• Wallabag.it! - Save to Instapaper - Save to Pocket -

    Pollution killed 9 million people in 2015

    First global look estimates the massive human and financial toll caused by pollution-related health problems.

    in Science News on October 20, 2017 09:50 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Dawn spacecraft will keep orbiting the dwarf planet Ceres indefinitely

    NASA just gave the Dawn spacecraft a second mission extension to orbit Ceres indefinitely.

    in Science News on October 20, 2017 07:15 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Problematic Neuropeptides And Statistics (PNAS)

    Back in May I discussed a paper published in PNAS which, I claimed, was using scientific terminology in a sloppy way. The authors, Pearce et al., used the word "neuropeptides" to refer to six molecules, but three of them weren't neuropeptides at all. The authors acknowledged this minor error and issued a correction. Now, it emerges that there may be more serious problems with the PNAS paper. In a letter published last week, researchers Patrick Jern and colleagues say that the statistics u

    in Discovery magazine - Neuroskeptic on October 20, 2017 04:17 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Retract, replace, retract: Beleaguered food researcher pulls article from JAMA journal (again)

    A high-profile food researcher who’s faced heavy criticism about his work has retracted the revised version of an article he’d already retracted last month. Yes, you read that right: Brian Wansink at Cornell University retracted the original article from JAMA Pediatrics in September, replacing it with a revised version. Now he’s retracting the revised version, citing […]

    The post Retract, replace, retract: Beleaguered food researcher pulls article from JAMA journal (again) appeared first on Retraction Watch.

    in Retraction watch on October 20, 2017 03:54 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Scientists battle over whether violence has declined over time

    People are no more violent in small-scale societies than in states, researchers contend.

    in Science News on October 20, 2017 01:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Estimate: Nearly 33,000 papers include misidentified cell lines. Experts talk ways to combat growing problem

    Although most researchers realize too many are using misidentified cell lines in their work, they may be shocked to see the scope of the problem: Approximately 32,755 articles report on research that relied on misidentified cells, according to a new report in PLoS ONE. And even though more people may be aware of the problem, it […]

    The post Estimate: Nearly 33,000 papers include misidentified cell lines. Experts talk ways to combat growing problem appeared first on Retraction Watch.

    in Retraction watch on October 20, 2017 12:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Resurrecting extinct species raises ethical questions

    'Rise of the Necrofauna' examines the technical and ethical challenges of bringing woolly mammoths and other long-gone creatures back from the dead.

    in Science News on October 20, 2017 11:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The effect of emotions on your behaviour depends partly on your expectations

    GettyImages-598165432.jpgBy Emma Young

    Will you get a better result from a business negotiation if you get angry or remain calm? What about a creative task – will you come up with more solutions to a problem if you’re excited, or relaxed?

    The answer, according a new study in Emotion, is that it depends at least in part on what you expect the impacts of emotions to be.

    Some theories linking emotion and behaviour hold that emotions activate fixed behavioural “programmes” (anger activates aggressive actions, for example). Others hold that while emotions do influence behaviour, how they do so depends upon the individual’s past experiences, and the current context. (Faced with a bullying boss, the anger you feel may lead you respond aggressively, if this has worked for you in the past; alternatively, it may prompt you to go off and strengthen bonds with colleagues.)

    Maya Tamir and Yochanan Bigman at the Hebrew University in Jerusalem, Israel, reasoned that if this second class of theory is correct, a given emotion will lead to a particular behaviour if a person expects it to do so – but if that expectation is not there, it won’t.

    For the first experiment, the researchers told volunteers that, as part of a study on peer influence, they would be completing a real negotiation task, with financial consequences. The negotiation was over the sharing of coloured chips. Each participant was given a table showing the monetary value of the chips, but they were also told that the other person’s table may not show the same values.

    Before going into the negotiation, half were assigned to an “angry” condition. They read testimonials purporting to be from people who had previously been successful at the negotiation task that included comments like, “Throughout the negotiation, I was persistent. Eventually I got angry and my partner felt compelled to give me what I wanted.” They also listened to “angry” music (music rated in a pilot study as inducing feelings of anger), such as Inquisition by the cello metal – yes, cello metal – band Apocalyptica. The control group read testimonials that did not mention emotions, but recommended being “reasonable”. They listened to music deemed to be emotionally neutral. Finally, the volunteers described their current emotional state, then went into the negotiation.

    The researchers found that the volunteers who said they felt angry made more money, but only if they’d read the testimonials advocating the benefits of anger, not if they hadn’t. Those who’d read the emotionally neutral testimonials did equally well, whether they felt angry or not.

    In another experiment, Tamir and Bigman recruited 159 more students, to look at how expectations about anger might affect performance on a first-person shooter video game.  Half the group was led to believe, via accounts from previous players, that feeling angry would help them kill more baddies, while the other half was led to believe that feeling calm would be beneficial. Those who expected anger to boost their performance played better if they actually felt angry, rather than relatively calm; in contrast, angry participants in the “calm is good” condition didn’t show this advantage. However, against the researchers’ expectations, feeling calm didn’t help the ‘calm is good’ group perhaps because in this context, the lower physiological arousal associated with calmness is a disadvantage, regardless of beliefs.

    For the final study, the researchers switched to creativity. Among people who were encouraged to believe that excitement benefits creativity, those who reported feeling excited did better (as measured by how many uses they could come up with for a brick) than those who reported feeling calm. In contrast, among the “calm is good” group, those who felt calm performed better than those who felt more excited – showing that there are contexts where a low arousal state can be advantageous if you believe it to be so.

    Clearly, more work is needed to explore just what types of performance can be influenced by expectations about the impacts of emotions, and actual emotional states. But this work does show that, as the researchers conclude, “At least in some cases, what we expect emotions to do may determine what they actually do.”

    Expectations Influence How Emotions Shape Behavior

    Emma Young (@EmmaELYoung) is Staff Writer at BPS Research Digest

    in The British Psychological Society - Research Digest on October 20, 2017 09:47 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Doubling up on ‘junk DNA’ helps make us human

    DNA duplicated only in humans may contribute to human traits and disease.

    in Science News on October 19, 2017 10:18 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Laws to protect athletes’ brains do reduce concussions — eventually

    Recurrent concussions among high school athletes went down about 2½ years after traumatic brain injury laws were on the books, a new study finds.

    in Science News on October 19, 2017 09:11 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Open Access Week 2017 – Open in Order to…

    As a proud co-founder of Open Access Week, we hope you will join us in celebrating progress and promoting awareness to help make Open Access – the founding principle of PLOS – the new norm in scholarship and research globally. This year’s theme is “Open in Order to…” and invites the community to focus on what openness enables.

    Since PLOS’ beginning, we’ve been open in order to accelerate progress in science and medicine through publishing, advocacy and innovation to benefit the research community and beyond. PLOS is open in order to ensure that: research outcomes are discoverable, accessible and available for discussion; science communication is constructive, transparent and verifiable; and publishing advances reproducibility, transparency and accountability.

    Join PLOS in an Open Access Week Event (and find other events near you):

    • Wed 10/25 5:30–8:00 pm PDT Open House & Poetry Slam at PLOS – Please join us at the PLOS office for refreshments, office tours to see how we work and an Open Mic Poetry Slam with guests invited to share poems, songs, or free verse on the OA Week theme: “Open in order to….” We’ll have fun prizes for all who choose to share!
    • Wed 10/25–Fri 10/27 FORCE 2017 | Changing the CultureAlison Mudditt, PLOS Chief Executive Officer and Emma Ganley, PLOS Biology Chief Editor will be in Berlin at this conference that brings together a diverse group of people interested in changing the way in which scholarly and scientific information is communicated and shared

    Explore PLOS Journals – which have now published more than 200,000 research articles:

    Follow PLOS Channels:

    Be Open in Order to:

    Get involved:

    • Learn about FASTR – As Open Access takes center stage with the Fair Access to Science and Technology Research Act in Congress, PLOS reaffirms its commitment to and support of Open Access
    • Join the conversation with PLOS Science Wednesdays 1:00 pm EDT – the Ask Me Anything (AMA) series with PLOS authors on redditscience

    Publish with PLOS and share your work with the world

    Stay in touch with PLOS

    Have a great Open Access Week!

    in The Official PLOS Blog on October 19, 2017 06:45 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The next wave of bird flu could be worse than ever

    Deadly bird flu can pass between ferrets through the air.

    in Science News on October 19, 2017 06:33 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Gene editing in the brain gets a major upgrade

    Scientists develop a new tool for precise genome editing in neurons

    Genome editing technologies have revolutionized biomedical science, providing a fast and easy way to modify genes. However, the technique allowing scientists to carryout the most precise edits, doesn’t work in cells that are no longer dividing – which includes most neurons in the brain. This technology had limited use in brain research, until now. Research Fellow Jun Nishiyama, M.D., Ph.D., Research Scientist, Takayasu Mikuni, M.D., Ph.D., and Scientific Director, Ryohei Yasuda, Ph.D. at the Max Planck Florida Institute for Neuroscience (MPFI) have developed a new tool that, for the first time, allows precise genome editing in mature neurons, opening up vast new possibilities in neuroscience research.

    This novel and powerful tool utilizes the newly discovered gene editing technology of CRISPR-Cas9, a viral defense mechanism originally found in bacteria. When placed inside a cell such as a neuron, the CRISPR-Cas9 system acts to damage DNA in a specifically targeted place. The cell then subsequently repairs this damage using predominantly two opposing methods; one being non-homologous end joining (NHEJ), which tends to be error prone, and homology directed repair (HDR), which is very precise and capable of undergoing specified gene insertions. HDR is the more desired method, allowing researchers flexibility to add, modify, or delete genes depending on the intended purpose.

    Coaxing cells in the brain to preferentially make use of the HDR DNA repair mechanism has been rather challenging. HDR was originally thought to only be available as a repair route for actively proliferating cells in the body. When precursor brain cells mature into neurons, they are referred to as post-mitotic or nondividing cells, making the mature brain largely inaccessible to HDR – or so researchers previously thought. The team has now shown that it is possible for post-mitotic neurons of the brain to actively undergo HDR, terming the strategy “vSLENDR (viral mediated single-cell labeling of endogenous proteins by CRISPR-Cas9-mediated homology-directed repair).” The critical key to the success of this process is the combined use of CRISPR-Cas9 and a virus.

    Adeno-associated virus (AAV) is a low immunogenic, nontoxic virus utilized by scientists as an efficient delivery mechanism for all kinds of genes. This virus can effectively provide the donor template necessary for HDR, increasing its efficiency. The team first packaged the necessary machinery for genome editing into the AAV and delivered it to neurons of transgenic Cas9 expressing mice, achieving spectacularly efficient HDR in post-mitotic neurons of the brain.
    They next created a dual-viral system allowing them to use the technology in animals that had not been engineered to express Cas9. They tested this dual-viral system in an aged Alzheimer’s disease mouse model showing that the vSLENDR technique can be applicable in pathological models even at advanced ages.

    vSLENDR is a powerful new tool for both basic and translational sciences alike, capable of the precise editing of genetic information regardless of cell type, cell maturity, brain region, or age. The new vSLENDR is more efficient, flexible, and concise, allowing researchers the potential to study a myriad of brain processes and functionalities with unprecedented ease. Equally important is its potential use in neuropathological disease models, accelerating research and the development of novel therapeutics; establishing today’s basic science as the foundation for tomorrow’s cures.

    This work was supported National Institute of Health, the Human Frontier Science Program and JST/PRESTO, Max Planck Florida Institute for Neuroscience and Max Planck Society. The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

    Virus-Mediated Genome Editing via Homology-Directed Repair in Mitotic and Postmitotic Cells in Mammalian Brain.

    Jun Nishiyama*, Takayasu Mikuni*, and Ryohei Yasuda
    *Co-firt authors

    Neuron, October 19 2017, Advance online publication.
    DOI: 10.1016/j.neuron.2017.10.004

    in Max Plank Florida Institute for Neuroscience on October 19, 2017 04:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    After journal retracts their paper, authors post rebuttal on arXiv

    In July 2017, just days after accepting and publishing a paper, a physics journal discovered “several scientific errors” and decided to retract it. But the authors—Alexander Kholmetskii and Tolga Yarman—strongly objected to the journal’s decision, so much so they published a detailed rebuttal to the retraction on the preprint server arXiv. The paper explores a […]

    The post After journal retracts their paper, authors post rebuttal on arXiv appeared first on Retraction Watch.

    in Retraction watch on October 19, 2017 03:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Science Exchange Honored by Goldman Sachs for Entrepreneurship

    Co-Founder and CEO Elizabeth Iorns Among 100 Most Intriguing Entrepreneurs at 2017 Builders + Innovators Summit

    Palo Alto, CA – October 19, 2017 – Goldman Sachs (NYSE:GS) is recognizing Elizabeth Iorns, Ph.D., co-founder and CEO of Science Exchange as one of the 100 Most Intriguing Entrepreneurs of 2017 at its Builders + Innovators Summit in Santa Barbara, California.

    Goldman Sachs selected Elizabeth as one of 100 entrepreneurs from multiple industries to be honored at the two-day event.

    The life sciences research community has been transformed by Elizabeth’s ability to execute upon her vision to transform the procurement and delivery of outsourced R&D services. Thanks to her tenacity and drive, and her deep understanding of the need for improved R&D efficiency, Science Exchange is enabling breakthrough scientific discoveries by providing researchers with an online platform for efficient access to the world’s best outsourced R&D service providers.

    “This is a tremendous honor and I’m excited to be recognized by Goldman Sachs along with these other inspiring entrepreneurs,” said Elizabeth Iorns, Ph.D., co-founder and CEO of Science Exchange.  “The work our team at Science Exchange has been doing in outsourced R&D is critical for driving scientific breakthroughs and innovation and I’m proud to lead the team in this charge.”

    “We are pleased to recognize Elizabeth Iorns as one of the most intriguing entrepreneurs of 2017,” said David M. Solomon, President and Co-Chief Operating Officer at Goldman Sachs. “This is the sixth year that we’ve hosted the Builders + Innovators Summit where emerging business leaders gather to discuss their common interests in building prosperous organizations.”

    For more than 145 years, Goldman Sachs has been advising and financing entrepreneurs as they launch and grow their businesses. In addition to honoring 100 entrepreneurs, the Summit consists of general sessions and clinics led by Goldman Sachs experts, seasoned entrepreneurs, academics and business leaders as well as resident scholars.

    About Elizabeth Iorns

    Elizabeth Iorns, Ph.D., is the CEO and Founder of Science Exchange. Elizabeth Iorns has transformed scientific research by radically improving the procurement and delivery of outsourced research and development (R&D) services. Elizabeth Iorns, Ph.D. (Institute of Cancer Research, London) was an Assistant Professor at University of Miami’s Miller School of Medicine, where she investigated breast cancer development and progression, before launching Science Exchange in 2011. Elizabeth’s work has been featured in multiple media outlets, and she regularly speaks at thought leadership events, such as the 2017 TechCrunch Disrupt event in San Francisco, 2017 Society for Laboratory Automation and Screening annual meeting and the 2016 MassBio CRO/CMO Symposium. Her recent honors include Nature’s “Ten People that Mattered,” WIRED’s “50 Women Who Are Changing The World,” and the “Kauffman Foundation Emerging Entrepreneur Award.” She is a finalist for 2017 Scrip Executive of the Year Award.

    About Science Exchange
    Science Exchange is the world’s leading and most secure platform for outsourced research, providing an efficient procure-to-pay platform for ordering 6,000+ services from a network of more than 2,500 qualified scientific service providers, all with pre-established contracts in place that protect client intellectual property and confidentiality. The platform increases access to innovation and improves productivity, freeing scientists from administrative tasks and delays associated with sourcing, establishing and managing service provider contracts. Additionally, the Science Exchange enterprise program enables large R&D organizations to consolidate research outsourcing spend into a single strategic relationship, driving efficiency, improving transparency and oversight, and delivering cost savings. Since being founded in 2011, Science Exchange has raised more than $58 million from Norwest Venture Partners, Maverick Capital Ventures, Union Square Ventures, Collaborative Fund, Index Ventures, OATV, the YC Continuity Fund, and others. For more information, visit www.ScienceExchange.com. Follow the company on Twitter @ScienceExchange.

    in The Science Exchange Blog on October 19, 2017 01:35 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Ethical concerns arise for head of controversial stem cell clinic

    Journals are raising ethical concerns about the research of a doctor who offers controversial embryonic stem cell treatments. Two journals have issued expressions of concern for three papers by Geeta Shroff, who was the subject of a 2012 CNN investigative documentary. All cite ethical concerns; one mentions the potential link between the procedure the authors […]

    The post Ethical concerns arise for head of controversial stem cell clinic appeared first on Retraction Watch.

    in Retraction watch on October 19, 2017 12:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    50 years ago, engineers tried catching commercial planes in nets

    Fifty years ago, aviation experts tried helping commercial aircraft come to a stop during landing by catching them in massive nets. The idea crash-landed for commercial flights, but it’s still used in the military.

    in Science News on October 19, 2017 11:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Reverse “stereotype threat” – women chess players perform better against men

    GettyImages-103660991.jpgBy Alex Fradera

    Stereotype threat is one of those social psychology concepts that has managed to break out of the academic world and into everyday conversation: the idea that a fear of conforming to stereotypes – for example, that girls struggle at maths – can make those stereotypes self-fulfilling, thanks to the adverse effect of anxiety and excessive self-consciousness on performance.

    A recent review suggested that stereotype threat has a robust but small-to-medium sized effect on performance, but a meta-analysis suggests that publication bias may be a problem in this literature, inflating the apparent size of the effect. Also, the majority of the work has been done under laboratory conditions, which may not reflect what happens in the wider world. So when a field study comes along, it’s worth paying attention to, and a paper published as a pre-print at PsyArXiv from Tom Stafford at the University of Sheffield looks at a domain involving high pressure, clear success criteria, and a presupposition that’s it’s more a guy thing: chess.

    The handy thing about chess is that we have so much solid data: vast databases of matches, and effective ranking systems that allow accurate predictions of who is likely to win upcoming matches. To date, lab-based studies have suggested that women playing chess do suffer from stereotype threat, so Stafford’s question is: what does that look like in real play?

    To find out, he explored a dataset of youngish (average age 32) players ranked officially by FIDE, the World Chess Federation, including 150,000 men and 16,000 women, and the outcomes of over five million games.

    The average man had a higher ranking – 2070 versus 1978 – meaning plenty of the games would put the women players in a challenging situation, which is where stereotype threat is most likely to manifest. And yet the data showed that whether playing a stronger, matched or equal player, women performed better when playing a man than they did a woman. In other words, the data revealed exactly the opposite pattern of performance as predicted by the concept of stereotype threat.

    Stafford looked closer at the data, to see whether the expected threat effect emerged under certain conditions, such as among younger and less experienced players; for older players who conceivably grew up around more sexist assumptions; or for players from national leagues where women are even more in the minority. Nothing changed the pattern: women perform better when playing men.

    Nor was there evidence that stereotype threat triggered women to drop the ball on matches they were well placed to win. Looking at matches where one player had a rating 500 or more points above the other, Stafford found that female favourites were upset by men in 3.5 per cent of cases, but female underdogs beat the male favourite even more often, in 3.7 per cent of cases.

    Stafford notes that another factor that increases the likelihood of stereotype effect is when the task attempted is unfamiliar, and this isn’t the case here: the women players had years of experience. Still, the data didn’t merely show no effect, but a reversed one, so there seems to be some sort of gender-related psychological process exerting an effect. Perhaps in domains where women are skilled and self-confident, anticipating a stereotype-related challenge actually sharpens their focus to buckle down. Or, says Stafford, maybe it’s an issue of male under-performance, whether “male underestimation of female opponents, misplaced chivalry, or ‘choking’ due the ego-threat of being beaten by a women.”

    This isn’t the first field investigation of stereotype threat to show different effects from laboratory studies. For example, Thomas Wei’s investigation of children’s maths performance found that gender primes before the task actually led girls to do better than normal. Findings like these don’t prove that stereotype threat is non-existent in every situation, but they do suggest it is not as ubiquitous or straightforward as some have claimed. Just as with many phenomena in our rich, complex real world, gendered assumptions about performance may not have the same influence in every situation.

    Female chess players outperform expectations when playing men

    Image: Actress Lauren Bacall and her husband actor Humphrey Bogart pictured playing chess, USA, circa 1955. (Photo by Archive Photos/Getty Images)

    Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest

    in The British Psychological Society - Research Digest on October 19, 2017 07:09 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The physics of mosquito takeoffs shows why you don’t feel a thing

    Even when full of blood, mosquitoes use more wing force than leg force to escape a host undetected — clue to why they’re so good at spreading disease.

    in Science News on October 18, 2017 10:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Caught Our Notice: Another retraction for researcher paid $100k to leave uni

    When Retraction Watch began in 2010, our co-founders Ivan Oransky and Adam Marcus quickly realized they couldn’t keep up with the hundreds of retractions that appeared each year.  And the problem has only gotten worse — although we’ve added staff, the number of retractions issued each year has increased dramatically. According to our growing database, just shy of […]

    The post Caught Our Notice: Another retraction for researcher paid $100k to leave uni appeared first on Retraction Watch.

    in Retraction watch on October 18, 2017 06:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Animal study reveals how a fever early in pregnancy can cause birth defects

    Using chicken embryos, study shows that heat itself, not an infectious agent, is the driving factor behind certain heart and facial birth defects.

    in Science News on October 18, 2017 06:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The newest AlphaGo mastered the game with no human input

    AlphaGo Zero is the first AI system of its kind to learn the game just by playing against itself.

    in Science News on October 18, 2017 05:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Conspiring with engineers helps make science great

    Acting Editor in Chief Elizabeth Quill says the passion to acquire knowledge and apply it lives in both engineers and scientists.

    in Science News on October 18, 2017 04:30 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Readers question photons colliding, black sea snakes and more

    Readers had questions about brain flexibility, black sea snakes and photon collisions.

    in Science News on October 18, 2017 04:15 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Being a vampire can be brutal. Here’s how bloodsuckers get by.

    Blood-sucking animals have specialized physiology and other tools to live on a diet rich in protein and lacking in some nutrients.

    in Science News on October 18, 2017 04:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Journal: Publish here, and we’ll pay you $500

    A new journal is offering something we’ve never seen before: A cash reward to corresponding authors of papers it publishes. Normally, in the case of open-access journals, researchers have to pay article processing charges (APCs). But Minimally Invasive Surgical Oncology, an open-access journal launched at the end of last year, flips the typical narrative — […]

    The post Journal: Publish here, and we’ll pay you $500 appeared first on Retraction Watch.

    in Retraction watch on October 18, 2017 03:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Predicting a soldier’s potential for developing depression and PTSD

    Statistics concerning the occurrence of post-traumatic stress disorder, or PTSD, in soldiers returning from combat vary widely depending on when a veteran gets tested for the mental illness.

    However, one fact remains constant: anyone who works in a combat environment or other high-stress environment like those created by military service are at risk of developing PTSD during their deployment or after they return home.

    This isn’t a new occurrence. Four out of five Vietnam veterans reported recent symptoms of PTSD when interviewed decades after the end of that conflict.

    A new study has suggested a potential solution to this problem: a series of validated, self-reported questions administered early in the solder’s career.

    These questions could help to predict a soldier’s potential for developing PTSD, depression or other mental illnesses as a direct result of their military service.

    Extended combat scenarios

    Between the operations being conducted in Iraq and Afghanistan, the U.S. military has been participating in combat operations for almost 15 years.

    These extended combat scenarios have led to an increasing need for psychological health services for military personnel and service members. Depending on when a soldier’s mental state is assessed, the rate of service members returning from combat with symptoms of PTSD ranges from 5 to 45 percent.

    Many symptoms don’t present until after the solider has returned home, which can make transitioning back to civilian life hard.

    The hypothesis that service members who are assessed before or during the beginning of their career will enable mental health professionals in the military to be better prepared is not a new one, but it hasn’t yet been explored sufficiently.

    Proactive mental health screenings could have two potential benefits, though: they could help reduce overall mental health care costs over time, and could cut down on the number of people who are at risk for mental illness or PTSD from being exposed to stressful scenarios.

    The methods

    The Army received the data for this study in three sources: soldier-provided information in the form of the pre- and post-deployment health assessments, the soldiers’ responses to the military Global Assessment Tools and Army demographic information.

    The goal of this was to examine this information for one of two outcomes:

    • Soldiers who return home without any mental health concerns
    • Soldiers who have returned home at risk for PTSD, depression, or other mental health diagnoses

    Based solely on the post-deployment health assessment, roughly 7 percent of the sampled soldiers screened positive for depression, and 11 percent screened positive for PTSD.

    Having the soldier’s pre-combat mental state proved essential in determining the potential for the development of these mental health issues.

    Initially, these pre-deployment mental health screenings could cost the organization more, but those costs would likely be offset by the money saved on post-deployment mental health care.

    The one major limitation of this study is the lack of actual clinical diagnosis — while the data trended toward depression and PTSD, there were no official diagnoses made. This is also due in part to the negative stigma that surrounds mental illness and prevents people from reporting their concerns.  PTSD in the military is a problem with no quick or easy solutions.

    This hypothesis could potentially help move military mental health care in the right direction, both by providing more tools for people suffering from PTSD and depression, and helping recruiters to determine who is at risk for developing mental health concerns due to the stresses of military service and combat scenarios.

    These early screenings could also potentially save the military hundreds of thousands of dollars in mental health care in the long run.

    The post Predicting a soldier’s potential for developing depression and PTSD appeared first on BMC Series blog.

    in BMC Series blog on October 18, 2017 02:20 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Researcher apologizes for ignoring early warnings about earthquake data

    In 2016, three researchers published data they had collected on a series of devastating earthquakes that hit Japan earlier that year. But, in late September 2017, one of the authors—Hiroyuki Goto—revealed that the Kumamoto Earthquake data contained “wide reaching errors”—and an outside expert had warned him the data might be problematic nine months earlier.   Goto, […]

    The post Researcher apologizes for ignoring early warnings about earthquake data appeared first on Retraction Watch.

    in Retraction watch on October 18, 2017 12:52 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    A brief critique of predictive coding

    Predictive coding is becoming a popular theory in neuroscience (see for example Clark 2013). In a nutshell, the general idea is that brains encode predictions of their sensory inputs. This is an appealing idea because superficially, it makes a lot of sense: functionally, the only reason why you would want to process sensory information is if it might impact your future, so it makes sense to try to predict your sensory inputs.

    There are substantial problems in the details of predictive coding theories, for example with the arbitrariness of the metric by which you judge that your prediction matches sensory inputs (what is important?), or the fact that predictive coding schemes encode both noise and signal. But I want to focus on the more fundamental problems. One has to with “coding”, the other with “predictive”.

    It makes sense that brains anticipate. But does it make sense that brains code? Coding is a metaphor of a communication channel, and this is generally not a great metaphor for what the brain might do, unless you fully embrace dualism. I discuss this at length in a recent paper (Is coding a relevant metaphor for the brain?) so I won’t repeat the entire argument here. Predictive coding is a branch of efficient coding, so the same fallacy underlies its logic: 1) neurons encode sensory inputs; 2) living organisms are efficient; => brains must encode efficiently. (1) is trivially true in the sense that one can define a mapping from sensory inputs to neural activity. (2) is probably true to some extent (evolutionary arguments). So the conclusion follows. Critiques of efficient coding have focused on the “efficient” part: maybe the brain is not that efficient after all. But the error is elsewhere: living organisms are certainly efficient, but it doesn’t follow that they are efficient at coding. They might be efficient at surviving and reproducing, and it is not obvious that it entails coding efficiency (see the last part of the abovementioned paper for a counter-example). So the real strong assumption is there: the main function of the brain is to represent sensory inputs.

    The second problem has to with “predictive”. It makes sense that an important function of brains, or in fact of any living organism, is to anticipate (see the great Anticipatory Systems by Robert Rosen). But to what extent do predictive coding schemes actually anticipate? First, in practice, those are generally not prediction schemes but compression schemes, in the sense that they do not tell us what will happen next but what happens now. This is at least the case of the classical Rao & Ballard (1999). Neurons encode the difference between expected input and actual input: this is compression, not prediction. It uses a sort of prediction in order to compress: other neurons (in higher layers) produce predictions of the inputs to those neurons, but the term prediction is used in the sense that the inputs are not known to the higher layer neurons, not that the “prediction” occurs before the inputs. Thus the term “predictive” is misleading because it is not used in a temporal sense.

    However, it is relatively easy to imagine how predictive coding might be about temporal predictions, although the neural implementation is not straightforward (delays etc). So I want to make a deeper criticism. I started by claiming that it is useful to predict sensory inputs. I am taking this back (I can because I said it was superficial reasoning). It is not useful to know what will happen. What is useful is to know what might happen, depending on what you do. If there is nothing you can do about the future, what is the functional use of predicting it? So what is useful is to predict the future conditionally to a different set of potential actions. This is about manipulating models of the world, not representing the present.

    in Romain Brette on October 18, 2017 11:11 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Moms tweak the timbre of their voice when talking to their babies

    Mothers shift the timbre, or quality, of their voice when talking to their babies, a change that happens in many different languages.

    in Science News on October 18, 2017 11:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The concept of “compensation” makes sense of several autism puzzles

    Screenshot 2017-10-18 09.47.38.pngOn British television last night, naturalist and TV presenter Chris Packham described how he hid his autistic traits for most of his life

    By Alex Fradera

    A process involved in neurodevelopmental disorders that we are only just beginning to understand is “compensation” – the way that a deficit can be partially or wholly masked by automatic mental processes and/or deliberate behavioural strategies. For instance, a person with dyslexia may achieve typical levels of reading ability after an earlier diagnosis, not because the disorder has gone away (subtle tests might show continuing problems in phonological processing, for example) but through the use of behavioural strategies, such as reverse-engineering a tricky word from the meaning of words around it. In a new review in Neuroscience and Biobehavioral Reviews Lucy Anne Livingston and Francesca Happé, at the Institute of Psychiatry in London, take us through what compensation might mean for autism.

    Compensation in autism could make sense of several puzzles. One is how high-risk individuals – with an autistic sibling, and showing markers for the disorder at the age of one – sometimes beat the odds and go on to seemingly normal development. Similarly, some individuals are diagnosed with autism, but in adulthood achieve what is termed a “good outcome”: functional social relationships, work life, and general independence. These cases could be explained by compensation mechanisms kicking in at different times. Meanwhile, people who remain undiagnosed until later life could have been relying to that point on compensation mechanisms that have become ineffective, perhaps because their lives have become more complex.

    Moreover, scientists are reassessing the prevalence of autism in girls and women, now understood to stand at around one female for every three males according to one analysis. The reason for the historical under-estimate – even fairly recently standing at a male to female ratio of four to one – and for why autism may present differently in women (who are often diagnosed later in life), may again be compensation; one source of evidence for this is that women with autism report a higher inclination to camouflage their difficulties in order to fit in socially.

    A core deficit of autism is an impairment in Theory of Mind: difficulty figuring out what people are thinking in order to make sense of their behaviour. Livingston and Happé asked themselves how this might be compensated. It’s possible that what neurotypical people achieve implicitly can also be achieved explicitly, by reasoning through situations to predict behaviour and motives. If true, it’s likely higher intelligence would assist this compensatory process. Consistent with this account, intelligence is one of the strongest correlates of “good outcome”; it also tends to be higher in the unaffected siblings of those with autistic spectrum disorders (ASD), but lower in women diagnosed with autism.

    Another factor likely to be relevant to autistic compensation is “executive function” – the suite of meta-cognitive functions that includes planning and inhibiting action, flexibility in thinking and switching focus. It’s easy to see how being able to prevent undesirable behaviours and plan appropriate social responses ahead of an interaction might prevent visible faux pas and allow an individual to pass as neurotypical. For a long time, executive dysfunction was seen as core to autism, and Livingston and Happé point out this could be because when that dysfunction was present, compensation was lacking, making autism symptoms more obvious.

    For autistic people and those around them, understanding the nature of their compensation may be very useful. Compensation may be deep or shallow: Livingston and Happé refer to the development of echolocation by blind people, which genuinely restores some of the functionality of sight (i.e. deep compensation), versus the use of a cane, which serves a much more circumscribed role (shallow compensation). In autism, two individuals might present as equally adjusted to social situations, such as responding to jokes, but the one relying on a shallow strategy (for example, join in whenever other people laugh) is vulnerable to making errors and may struggle in novel situations (e.g. a one-on-one date).

    Moreover, compensatory strategies are likely to exact a cost, drawing on resources that would normally be invested into other tasks. A common complaint from those on the spectrum is it’s hard work to “act normal” – as recently expressed by TV presenter Chris Packham (see footnote). Diagnosed with Asperger’s later in life, Packham says he was “forced to develop” a number of coping mechanisms. Individuals who spent more of their life undiagnosed – and hence without a way to make sense of their difference – are likely to have spent extended periods working to pass invisibly in society, and this may go some way to explain the higher levels of suicidal ideation in this group – at 66 per cent, far higher than in those diagnosed in childhood. Understanding different forms of compensation and their consequences may be an important step in helping autistic people manage their mental health more effectively.

    Although it’s early days, we’re starting to understand how to identify compensation in autism. Work with “good outcome” individuals shows that with sufficiently sensitive tasks, such as anticipating where people direct their gaze in complex social scenarios, it’s possible to pick up Theory of Mind deficits that were otherwise undetectable. The next step, argue the authors of this new review, is to develop a gold-standard measure that we agree captures the core, deep marker of Theory of Mind deficits in ASD, just as precise phonological measures do in dyslexia. Through this, we can not only understand the disorder at a scientific, medical level, but we can arrive at a personalised account of the ways individuals live with the disorder, the situations that may challenge them the most, and the psychological toll that they pay to pass in neurotypical cultures.

    Conceptualising compensation in neurodevelopmental disorders: Reflections from autism spectrum disorder

    Chris Packham: Asperger’s and Me was broadcast last night on British television and is available in some regions on BBC iPlayer

    Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest

    in The British Psychological Society - Research Digest on October 18, 2017 08:57 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Dream jobs in research: teaching conservationists – and penguins in the office

    This conservation biologist finds ways to make her research count in the wider world; what’s your dream job?

    in Elsevier Connect on October 18, 2017 07:38 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Self-taught AI is best yet at strategy game Go

    Artificial-intelligence program AlphaGo Zero trained in just days, without any human input.

    Nature News doi: 10.1038/nature.2017.22858

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Sleeping sickness can now be cured with pills

    Researchers seek approval from regulators for this quicker, easier treatment.

    Nature News doi: 10.1038/nature.2017.22856

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Efforts to save leading Hungarian university hit hurdle

    US-registered Central European University faces another year of uncertainty over whether it can continue to operate in Hungary.

    Nature News doi: 10.1038/nature.2017.22855

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Mysterious particles spotted in Saturn’s atmosphere

    Source may be dust shed by planet’s iconic rings, according to data from NASA's doomed Cassini probe.

    Nature News doi: 10.1038/nature.2017.22838

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Top Chinese university to consider social-media posts in researcher evaluations

    Controversial policy means mainstream media are starting to rival rigorous academic publications in some universities in China.

    Nature News doi: 10.1038/nature.2017.22822

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The Human Cell Atlas: from vision to reality

    As an ambitious project to map all the cells in the human body gets officially under way, Aviv Regev, Sarah Teichmann and colleagues outline some key challenges.

    Nature News doi: 10.1038/550451a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The second Renaissance

    Ian Goldin calls on scientists to help society to weather the disruptive transformations afoot.

    Nature 550 327 doi: 10.1038/550327a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Lessons from history for the future of work

    Global comparisons of previous social and economic upheavals suggest that what is to come depends on where you are now, argues Robert C. Allen.

    Nature 550 321 doi: 10.1038/550321a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The shape of work to come

    Three ways that the digital revolution is reshaping workforces around the world.

    Nature 550 316 doi: 10.1038/550316a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The future of work

    Digital technologies are upending the workforce. The right research can tell us how.

    Nature 550 315 doi: 10.1038/550315a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    New definitions of scientific units are on the horizon

    Metrologists are poised to change how scientists measure the Universe.

    Nature 550 312 doi: 10.1038/550312a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Epic star collision, asteroid fly-by and journal resignations

    The week in science: 13–19 October 2017.

    Nature 550 306 doi: 10.1038/550306a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Blue is in the eye of the bee-holder

    Flowers have evolved an ingenious way to attract pollinators.

    Nature 550 302 doi: 10.1038/550302a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Science must examine the future of work

    As automation changes employment, researchers should gather the evidence to help map the implications.

    Nature 550 301 doi: 10.1038/550301b

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Molecular basis of USP7 inhibition by selective small-molecule inhibitors

    Ubiquitination controls the stability of most cellular proteins, and its deregulation contributes to human diseases including cancer. Deubiquitinases remove ubiquitin from proteins, and their inhibition can induce the degradation of selected proteins, potentially including otherwise ‘undruggable’ targets. For example, the inhibition of ubiquitin-specific protease 7 (USP7) results in the degradation of the oncogenic E3 ligase MDM2, and leads to re-activation of the tumour suppressor p53 in various cancers. Here we report that two compounds, FT671 and FT827, inhibit USP7 with high affinity and specificity in vitro and within human cells. Co-crystal structures reveal that both compounds target a dynamic pocket near the catalytic centre of the auto-inhibited apo form of USP7, which differs from other USP deubiquitinases. Consistent with USP7 target engagement in cells, FT671 destabilizes USP7 substrates including MDM2, increases levels of p53, and results in the transcription of p53 target genes, induction of the tumour suppressor p21, and inhibition of tumour growth in mice.

    Nature doi: 10.1038/nature24451

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    The dynamics of molecular evolution over 60,000 generations

    The outcomes of evolution are determined by a stochastic dynamical process that governs how mutations arise and spread through a population. However, it is difficult to observe these dynamics directly over long periods and across entire genomes. Here we analyse the dynamics of molecular evolution in twelve experimental populations of Escherichia coli, using whole-genome metagenomic sequencing at five hundred-generation intervals through sixty thousand generations. Although the rate of fitness gain declines over time, molecular evolution is characterized by signatures of rapid adaptation throughout the duration of the experiment, with multiple beneficial variants simultaneously competing for dominance in each population. Interactions between ecological and evolutionary processes play an important role, as long-term quasi-stable coexistence arises spontaneously in most populations, and evolution continues within each clade. We also present evidence that the targets of natural selection change over time, as epistasis and historical contingency alter the strength of selection on different genes. Together, these results show that long-term adaptation to a constant environment can be a more complex and dynamic process than is often assumed.

    Nature doi: 10.1038/nature24287

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Disorder in convergent floral nanostructures enhances signalling to bees

    Diverse forms of nanoscale architecture generate structural colour and perform signalling functions within and between species. Structural colour is the result of the interference of light from approximately regular periodic structures; some structural disorder is, however, inevitable in biological organisms. Is this disorder functional and subject to evolutionary selection, or is it simply an unavoidable outcome of biological developmental processes? Here we show that disordered nanostructures enable flowers to produce visual signals that are salient to bees. These disordered nanostructures (identified in most major lineages of angiosperms) have distinct anatomies but convergent optical properties; they all produce angle-dependent scattered light, predominantly at short wavelengths (ultraviolet and blue). We manufactured artificial flowers with nanoscale structures that possessed tailored levels of disorder in order to investigate how foraging bumblebees respond to this optical effect. We conclude that floral nanostructures have evolved, on multiple independent occasions, an effective degree of relative spatial disorder that generates a photonic signature that is highly salient to insect pollinators.

    Nature doi: 10.1038/nature24285

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Structure of phycobilisome from the red alga Griffithsia pacifica

    Life on Earth depends on photosynthesis for its conversion of solar energy to chemical energy. Photosynthetic organisms have developed a variety of light-harvesting systems to capture sunlight. The largest light-harvesting complex is the phycobilisome (PBS), the main light-harvesting antenna in cyanobacteria and red algae. It is composed of phycobiliproteins and linker proteins but the assembly mechanisms and energy transfer pathways of the PBS are not well understood. Here we report the structure of a 16.8-megadalton PBS from a red alga at 3.5 Å resolution obtained by single-particle cryo-electron microscopy. We modelled 862 protein subunits, including 4 linkers in the core, 16 rod–core linkers and 52 rod linkers, and located a total of 2,048 chromophores. This structure reveals the mechanisms underlying specific interactions between linkers and phycobiliproteins, and the formation of linker skeletons. These results provide a firm structural basis for our understanding of complex assembly and the mechanisms of energy transfer within the PBS.

    Nature doi: 10.1038/nature24278

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Indirect effects drive coevolution in mutualistic networks

    Ecological interactions have been acknowledged to play a key role in shaping biodiversity. Yet a major challenge for evolutionary biology is to understand the role of ecological interactions in shaping trait evolution when progressing from pairs of interacting species to multispecies interaction networks. Here we introduce an approach that integrates coevolutionary dynamics and network structure. Our results show that non-interacting species can be as important as directly interacting species in shaping coevolution within mutualistic assemblages. The contribution of indirect effects differs among types of mutualism. Indirect effects are more likely to predominate in nested, species-rich networks formed by multiple-partner mutualisms, such as pollination or seed dispersal by animals, than in small and modular networks formed by intimate mutualisms, such as those between host plants and their protective ants. Coevolutionary pathways of indirect effects favour ongoing trait evolution by promoting slow but continuous reorganization of the adaptive landscape of mutualistic partners under changing environments. Our results show that coevolution can be a major process shaping species traits throughout ecological networks. These findings expand our understanding of how evolution driven by interactions occurs through the interplay of selection pressures moving along multiple direct and indirect pathways.

    Nature doi: 10.1038/nature24273

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Inflammatory memory sensitizes skin epithelial stem cells to tissue damage

    The skin barrier is the body’s first line of defence against environmental assaults, and is maintained by epithelial stem cells (EpSCs). Despite the vulnerability of EpSCs to inflammatory pressures, neither the primary response to inflammation nor its enduring consequences are well understood. Here we report a prolonged memory to acute inflammation that enables mouse EpSCs to hasten barrier restoration after subsequent tissue damage. This functional adaptation does not require skin-resident macrophages or T cells. Instead, EpSCs maintain chromosomal accessibility at key stress response genes that are activated by the primary stimulus. Upon a secondary challenge, genes governed by these domains are transcribed rapidly. Fuelling this memory is Aim2, which encodes an activator of the inflammasome. The absence of AIM2 or its downstream effectors, caspase-1 and interleukin-1β, erases the ability of EpSCs to recollect inflammation. Although EpSCs benefit from inflammatory tuning by heightening their responsiveness to subsequent stressors, this enhanced sensitivity probably increases their susceptibility to autoimmune and hyperproliferative disorders, including cancer.

    Nature doi: 10.1038/nature24271

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Mastering the game of Go without human knowledge

    A long-standing goal of artificial intelligence is an algorithm that learns, tabula rasa, superhuman proficiency in challenging domains. Recently, AlphaGo became the first program to defeat a world champion in the game of Go. The tree search in AlphaGo evaluated positions and selected moves using deep neural networks. These neural networks were trained by supervised learning from human expert moves, and by reinforcement learning from self-play. Here we introduce an algorithm based solely on reinforcement learning, without human data, guidance or domain knowledge beyond game rules. AlphaGo becomes its own teacher: a neural network is trained to predict AlphaGo’s own move selections and also the winner of AlphaGo’s games. This neural network improves the strength of the tree search, resulting in higher quality move selection and stronger self-play in the next iteration. Starting tabula rasa, our new program AlphaGo Zero achieved superhuman performance, winning 100–0 against the previously published, champion-defeating AlphaGo.

    Nature 550 354 doi: 10.1038/nature24270

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Single-molecule imaging reveals receptor–G protein interactions at cell surface hot spots

    G-protein-coupled receptors mediate the biological effects of many hormones and neurotransmitters and are important pharmacological targets. They transmit their signals to the cell interior by interacting with G proteins. However, it is unclear how receptors and G proteins meet, interact and couple. Here we analyse the concerted motion of G-protein-coupled receptors and G proteins on the plasma membrane and provide a quantitative model that reveals the key factors that underlie the high spatiotemporal complexity of their interactions. Using two-colour, single-molecule imaging we visualize interactions between individual receptors and G proteins at the surface of living cells. Under basal conditions, receptors and G proteins form activity-dependent complexes that last for around one second. Agonists specifically regulate the kinetics of receptor–G protein interactions, mainly by increasing their association rate. We find hot spots on the plasma membrane, at least partially defined by the cytoskeleton and clathrin-coated pits, in which receptors and G proteins are confined and preferentially couple. Imaging with the nanobody Nb37 suggests that signalling by G-protein-coupled receptors occurs preferentially at these hot spots. These findings shed new light on the dynamic interactions that control G-protein-coupled receptor signalling.

    Nature doi: 10.1038/nature24264

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Photobiology: How flowers get the blues to lure bees

    The petals of a range of flowers harbour repeated patterns of nanostructures that show similar levels of disorder across species. This degree of disorder produces a blue halo of scattered light that helps bees to find flowers.

    Nature doi: 10.1038/nature24155

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Inflammation: Memory beyond immunity

    Epithelial stem cells maintain the skin's epidermis and promote wound healing in response to injury. Scientists from two fields discuss implications of the discovery that these stem cells harbour a memory of previous injuries, which enables skin to respond rapidly to subsequent assaults.

    Nature doi: 10.1038/nature24154

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Molecular evolution: No escape from the tangled bank

    Ecological interactions emerge spontaneously in an experimental study of bacterial populations cultured for 60,000 generations, and sustain rapid evolution by natural selection.

    Nature doi: 10.1038/nature24152

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Glucose feeds the TCA cycle via circulating lactate

    Mammalian tissues are fuelled by circulating nutrients, including glucose, amino acids, and various intermediary metabolites. Under aerobic conditions, glucose is generally assumed to be burned fully by tissues via the tricarboxylic acid cycle (TCA cycle) to carbon dioxide. Alternatively, glucose can be catabolized anaerobically via glycolysis to lactate, which is itself also a potential nutrient for tissues and tumours. The quantitative relevance of circulating lactate or other metabolic intermediates as fuels remains unclear. Here we systematically examine the fluxes of circulating metabolites in mice, and find that lactate can be a primary source of carbon for the TCA cycle and thus of energy. Intravenous infusions of 13C-labelled nutrients reveal that, on a molar basis, the circulatory turnover flux of lactate is the highest of all metabolites and exceeds that of glucose by 1.1-fold in fed mice and 2.5-fold in fasting mice; lactate is made primarily from glucose but also from other sources. In both fed and fasted mice, 13C-lactate extensively labels TCA cycle intermediates in all tissues. Quantitative analysis reveals that during the fasted state, the contribution of glucose to tissue TCA metabolism is primarily indirect (via circulating lactate) in all tissues except the brain. In genetically engineered lung and pancreatic cancer tumours in fasted mice, the contribution of circulating lactate to TCA cycle intermediates exceeds that of glucose, with glutamine making a larger contribution than lactate in pancreatic cancer. Thus, glycolysis and the TCA cycle are uncoupled at the level of lactate, which is a primary circulating TCA substrate in most tissues and tumours.

    Nature doi: 10.1038/nature24057

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Network control principles predict neuron function in the Caenorhabditis elegans connectome

    Recent studies on the controllability of complex systems offer a powerful mathematical framework to systematically explore the structure–function relationship in biological, social, and technological networks. Despite theoretical advances, we lack direct experimental proof of the validity of these widely used control principles. Here we fill this gap by applying a control framework to the connectome of the nematode Caenorhabditis elegans, allowing us to predict the involvement of each C. elegans neuron in locomotor behaviours. We predict that control of the muscles or motor neurons requires 12 neuronal classes, which include neuronal groups previously implicated in locomotion by laser ablation, as well as one previously uncharacterized neuron, PDB. We validate this prediction experimentally, finding that the ablation of PDB leads to a significant loss of dorsoventral polarity in large body bends. Importantly, control principles also allow us to investigate the involvement of individual neurons within each neuronal class. For example, we predict that, within the class of DD motor neurons, only three (DD04, DD05, or DD06) should affect locomotion when ablated individually. This prediction is also confirmed; single cell ablations of DD04 or DD05 specifically affect posterior body movements, whereas ablations of DD02 or DD03 do not. Our predictions are robust to deletions of weak connections, missing connections, and rewired connections in the current connectome, indicating the potential applicability of this analytical framework to larger and less well-characterized connectomes.

    Nature doi: 10.1038/nature24056

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Mfsd2b is essential for the sphingosine-1-phosphate export in erythrocytes and platelets

    Sphingosine-1-phosphate (S1P), a potent signalling lipid secreted by red blood cells and platelets, plays numerous biologically significant roles. However, the identity of its long-sought exporter is enigmatic. Here we show that the major facilitator superfamily transporter 2b (Mfsd2b), an orphan transporter, is essential for S1P export from red blood cells and platelets. Comprehensive lipidomic analysis indicates a dramatic and specific accumulation of S1P species in Mfsd2b knockout red blood cells and platelets compared with that of wild-type controls. Consistently, biochemical assays from knockout red blood cells, platelets, and cell lines overexpressing human and mouse Mfsd2b proteins demonstrate that Mfsd2b actively exports S1P. Plasma S1P level in knockout mice is significantly reduced by 42–54% of that of wild-type level, indicating that Mfsd2b pathway contributes approximately half of the plasma S1P pool. The reduction of plasma S1P in knockout mice is insufficient to cause blood vessel leakiness, but it does render the mice more sensitive to anaphylactic shock. Stress-induced erythropoiesis significantly increased plasma S1P levels and knockout mice were sensitive to these treatments. Surprisingly, knockout mice exhibited haemolysis associated with red blood cell stomatocytes, and the haemolytic phenotype was severely increased with signs of membrane fragility under stress erythropoiesis. We show that S1P secretion by Mfsd2b is critical for red blood cell morphology. Our data reveal an unexpected physiological role of red blood cells in sphingolipid metabolism in circulation. These findings open new avenues for investigating the signalling roles of S1P derived from red blood cells and platelets.

    Nature doi: 10.1038/nature24053

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    USP7 small-molecule inhibitors interfere with ubiquitin binding

    The ubiquitin system regulates essential cellular processes in eukaryotes. Ubiquitin is ligated to substrate proteins as monomers or chains and the topology of ubiquitin modifications regulates substrate interactions with specific proteins. Thus ubiquitination directs a variety of substrate fates including proteasomal degradation. Deubiquitinase enzymes cleave ubiquitin from substrates and are implicated in disease; for example, ubiquitin-specific protease-7 (USP7) regulates stability of the p53 tumour suppressor and other proteins critical for tumour cell survival. However, developing selective deubiquitinase inhibitors has been challenging and no co-crystal structures have been solved with small-molecule inhibitors. Here, using nuclear magnetic resonance-based screening and structure-based design, we describe the development of selective USP7 inhibitors GNE-6640 and GNE-6776. These compounds induce tumour cell death and enhance cytotoxicity with chemotherapeutic agents and targeted compounds, including PIM kinase inhibitors. Structural studies reveal that GNE-6640 and GNE-6776 non-covalently target USP7 12 Å distant from the catalytic cysteine. The compounds attenuate ubiquitin binding and thus inhibit USP7 deubiquitinase activity. GNE-6640 and GNE-6776 interact with acidic residues that mediate hydrogen-bond interactions with the ubiquitin Lys48 side chain, suggesting that USP7 preferentially interacts with and cleaves ubiquitin moieties that have free Lys48 side chains. We investigated this idea by engineering di-ubiquitin chains containing differential proximal and distal isotopic labels and measuring USP7 binding by nuclear magnetic resonance. This preferential binding protracted the depolymerization kinetics of Lys48-linked ubiquitin chains relative to Lys63-linked chains. In summary, engineering compounds that inhibit USP7 activity by attenuating ubiquitin binding suggests opportunities for developing other deubiquitinase inhibitors and may be a strategy more broadly applicable to inhibiting proteins that require ubiquitin binding for full functional activity.

    Nature doi: 10.1038/nature24006

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Social behaviour shapes hypothalamic neural ensemble representations of conspecific sex

    All animals possess a repertoire of innate (or instinctive) behaviours, which can be performed without training. Whether such behaviours are mediated by anatomically distinct and/or genetically specified neural pathways remains unknown. Here we report that neural representations within the mouse hypothalamus, that underlie innate social behaviours, are shaped by social experience. Oestrogen receptor 1-expressing (Esr1+) neurons in the ventrolateral subdivision of the ventromedial hypothalamus (VMHvl) control mating and fighting in rodents. We used microendoscopy to image Esr1+ neuronal activity in the VMHvl of male mice engaged in these social behaviours. In sexually and socially experienced adult males, divergent and characteristic neural ensembles represented male versus female conspecifics. However, in inexperienced adult males, male and female intruders activated overlapping neuronal populations. Sex-specific neuronal ensembles gradually separated as the mice acquired social and sexual experience. In mice permitted to investigate but not to mount or attack conspecifics, ensemble divergence did not occur. However, 30 minutes of sexual experience with a female was sufficient to promote the separation of male and female ensembles and to induce an attack response 24 h later. These observations uncover an unexpected social experience-dependent component to the formation of hypothalamic neural assemblies controlling innate social behaviours. More generally, they reveal plasticity and dynamic coding in an evolutionarily ancient deep subcortical structure that is traditionally viewed as a ‘hard-wired’ system.

    Nature 550 388 doi: 10.1038/nature23885

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Breaking and entering

    Escape is not an option.

    Nature 550 424 doi: 10.1038/550424a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Cancer treatment: Bacterial snack attack deactivates a drug

    Tumour cells can develop intrinsic adaptations that make them less susceptible to chemotherapy. It emerges that extrinsic bacterial action can also enable tumour cells to escape the effects of drug treatment.

    Nature 550 337 doi: 10.1038/550337a

    in Nature Biological Sciences Research on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    PhD students: side jobs are no solution

    Nature 550 333 doi: 10.1038/550333e

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    PhD students: living wage key to diversity

    Nature 550 333 doi: 10.1038/550333d

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Open data: Spot data glitches before publication

    Nature 550 333 doi: 10.1038/550333c

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Ornithology: Danish dairy farmer delivers data coup

    Nature 550 333 doi: 10.1038/550333b

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Federal funding: Stifled by budgets, not irrelevance

    Nature 550 333 doi: 10.1038/550333a

    in Nature News & Comment on October 18, 2017 12:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Here’s what space toilets can teach us about finding signs of alien life

    Lessons learned from flushing space toilets can help researchers plan life-hunting missions to icy moons.

    in Science News on October 17, 2017 09:38 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    How volcanoes may have ended the dynasty of Ptolemy and Cleopatra

    Volcanic ash in polar ice reveal a link between eruptions and the timing of revolts in Cleopatra’s Egypt.

    in Science News on October 17, 2017 07:54 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Cross-Journal Initiative Helps Manuscripts Take Flight

    All properly executed science deserves to be published as quickly as possible. One common frustration of scientists related to publication speed is the review-rejection cycle that in action resembles a cross between cycling on a hamster wheel and jumping through a hoola-hoop. To offer authors a way out of this cycle of delay, PLOS launched a journal transfer initiative earlier this year that provides authors an alternative to starting from scratch for papers not initially accepted by a subset of PLOS journals.

    How It Works

    Manuscripts submitted to PLOS Computational Biology, PLOS Genetics, PLOS Neglected Tropical Diseases or PLOS Pathogens undergo the usual rigorous peer review. The paper’s editors assess the reviews and if they decide the work does not meet the journal’s criteria for perceived novelty or impact but is sound, well-designed and well-executed, they will offer acceptance and publication in the multidisciplinary journal, PLOS ONE. Publication can take place in as little as three weeks after the offer is accepted by the authors.

    Papers which merit publication will go through the peer review and revision process only once, saving authors, reviewers and academic editors time, speeding the way to publication for quality research.

    Why It Works

    The benefit to authors is that instead of rejecting the paper outright, editors now may use the decision letter to offer either immediate publication or publication after minor revisions. Importantly, to move the paper along faster for authors – rather than moving the goal posts – the same academic editor will consider the revision. This also ensures consistency of the feedback to authors and expedites the work for editors. Provided the authors agree to the offer, the manuscript will be published in PLOS ONE with both the original date of submission to PLOS Computational Biology, PLOS Genetics, PLOS Neglected Tropical Diseases or PLOS Pathogens and the name of that journal’s academic editor listed in the article’s metadata. As for all articles published by PLOS, this metadata appears together with citation, copyright, data availability, funding and competing interest information.

    Open In Order To Succeed

    PLOS has piloted this initiative over the past six months and we’re pleased to report that with substantial support from journal editorial boards and uptake from authors, we will continue this initiative that relieves authors, reviewers and editors of some of the repetition involved in publishing while bringing quality work to the public, faster. There are now notifications of the program on the relevant journal Editorial and Peer Review Process pages. Alongside existing manuscript transfer routes between PLOS journals, this newest initiative offers an effective means for scientists to rapidly communicate ideas, results and discoveries to each other and to the broader public.

    Open Access has changed the way readers and researchers around the world discover, use and reuse the scientific literature. Open data provides opportunities for new analysis, new discovery and even previously unrecognized new directions in research. Together with open source software, open source hardware and preprint servers, forward movement along the path toward a more Open Science has the potential to expand the venues, styles, and frequency of sharing work. Let your manuscript take flight! PLOS authors who take this opportunity for rapid publication in PLOS ONE can play an active role in accelerating the discovery and dissemination of their work. With International Open Access Week right around the corner, what better motto to adopt than Open In Order To Succeed—for it is success that we seek for reviewers, editors and most importantly, all authors.

    in The Official PLOS Blog on October 17, 2017 07:09 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    This stretchy implant could help kids avoid repeated open-heart surgeries

    A new type of surgical implant grows along with its recipient.

    in Science News on October 17, 2017 03:58 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    21 faculty at Johns Hopkins threaten to resign from board if journal doesn’t retract paper

    More than 20 faculty members at Johns Hopkins University have signed a letter to Scientific Reports saying they will resign from the editorial board if the journal doesn’t retract a 2016 paper. The paper is problematic, they argue, because a biologist at Johns Hopkins claims it plagiarized his work. One of that biologist’s colleagues at […]

    The post 21 faculty at Johns Hopkins threaten to resign from board if journal doesn’t retract paper appeared first on Retraction Watch.

    in Retraction watch on October 17, 2017 03:22 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Here’s a breakdown of the animals that crossed the Pacific on 2011 tsunami debris

    Hundreds of marine animals from Japan have washed up on U.S. beaches since the destructive 2011 earthquake and tsunami.

    in Science News on October 17, 2017 03:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    A universal flu shot may be nearing reality

    Scientists are developing a universal vaccine against flu, making annual shots a thing of the past.

    in Science News on October 17, 2017 12:52 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Boys will be boys: Data error prompts U-turn on study of sex differences in school

    The authors of a 2017 paper on emotional and behavioral gaps between boys and girls have retracted the article after discovering a coding error that completely undermined their conclusions. The revelation prompted the researchers to republish their findings in the same journal, this time with a title that flips the narrative. The PsychJournal study, first […]

    The post Boys will be boys: Data error prompts U-turn on study of sex differences in school appeared first on Retraction Watch.

    in Retraction watch on October 17, 2017 12:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Believers in conspiracy theories and the paranormal are more likely to see “illusory patterns”

    GettyImages-177765632.jpgBy Emma Young

    Democratic bankers caused the global financial crisis to get Barack Obama elected. 

    Horoscopes are right too often for it to be a coincidence. 

    Irrational beliefs – unfounded, unscientific and illogical assumptions about the world – are widespread among “the population of normal, mentally sane adults” note the authors of a new study in European Journal of Social Psychology. It’s been proposed that they arise from a mistaken perception of patterns in the world. But though this idea is popular among psychologists, there’s been surprisingly little direct evidence in favour of it. The new work, led by Jan-Willem van Prooijen at the Free University of Amsterdam, helps to fill the void.

    Pattern perception is a crucial cognitive ability. It allows us to identify meaningful relationships between events – such as “red traffic light means danger” or “drinking water quenches thirst”. When people join the dots between events that are in fact unrelated (I wore red socks and aced my exam – they are “lucky socks”), they engage in so-called illusory pattern perception.

    To explore whether an adherence to conspiracy theories or a belief in the supernatural really are grounded in illusory pattern perception, the researchers devised a series of studies.

    First, they assessed belief in existing, well-known – and also fictitious – conspiracy theories in a group of 264 American adults. The participants were asked, for example, to indicate, on a scale of 1 to 9, how strongly they believed in the statement: “The US government had advance knowledge of the 9/11 attacks”. Their belief in the supernatural was evaluated using a scale that measured agreement with statements like “I think I could learn to read other people’s minds if I wanted to”.

    When shown the results of a series of randomly generated coin tosses, people who scored relatively highly on these two scales were more likely to mistakenly perceive patterns – they believed that the series of heads and tails wasn’t random even though it was. “These findings are the first to directly suggest a relationship between belief in conspiracy theories and pattern perception, and [to] conceptually replicate this relationship for supernatural beliefs,” the researchers wrote.

    In further studies with different groups, they explored this further. To investigate whether spotting patterns in general – whether they’re illusory or real – can stoke irrational beliefs, they asked volunteers to what extent they saw patterns in paintings by two modern artists: Victor Vasarely (a French-Hungarian artist whose geometric abstract art contains obvious patterns) and Jackson Pollock (an abstract expressionist painter whose work the researchers described as “unstructured” and therefore likely to feature only illusory patterns).

    Only a perception of patterns in the unstructured Pollack paintings was correlated with belief in existing conspiracy theories, fictitious conspiracy theories (about purported underhand activities of a beverage company, for instance) and supernatural beliefs. Seeing patterns in the highly structured Vasarely paintings was unrelated to these beliefs.

    In another study, the researchers found that reading about paranormal or conspiracy beliefs (but not sceptical writings) caused a slight increase in the perception of patterns in coin tosses, paintings, and also “life” (as measured by agreement with statements like “Societal events that seem unrelated frequently are in fact related”). They further found that reading about one conspiracy theory made volunteers more likely to believe in other conspiracy theories. This supports the idea that conspiracy theorising increases the perception of illusory patterns in world events, the researchers said.

    Irrational beliefs are not necessarily harmless, as the researchers note. Belief in conspiracy theories is linked to increased hostility and radicalisation, while supernatural beliefs may lead people to hand over money to spiritual healers or tarot card readers. Uncertain times breed these kinds of beliefs, which can be seen as ways to make an unpredictable and potentially threatening environment feel more predictable.

    “The present findings offer empirical evidence for the role of illusory pattern perception in irrational beliefs,” the researchers write in their paper. “We conclude that illusory pattern perception is a central cognitive ingredient of beliefs in conspiracy theories and supernatural phenomena.”

    Connecting the dots: Illusory pattern perception predicts belief in conspiracies and the supernatural

    Emma Young (@EmmaELYoung) is Staff Writer at BPS Research Digest

    in The British Psychological Society - Research Digest on October 17, 2017 09:44 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    It shouldn’t happen to a researcher: top 6 lab book disasters

    What can go wrong with paper lab notebooks – and how Hivebench can prevent these problems

    in Elsevier Connect on October 17, 2017 08:25 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    New physics books don’t censor the math behind reality

    Special Relativity and Classical Theory and The Physical World offer deep dives into physical reality’s mathematical foundations.

    in Science News on October 16, 2017 07:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Gut fungi might be linked to obesity and inflammatory bowel disorders

    Fungi are overlooked contributors to health and disease.

    in Science News on October 16, 2017 06:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    To understand the origins of pain, ask a flatworm

    A danger-sensing protein responds to hydrogen peroxide in planarians, results that hint at the evolutionary origins of people’s pain sensing.

    in Science News on October 16, 2017 04:46 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Division director leaving U.S. research watchdog after nearly 15 years

    The director of the Division of Investigative Oversight at the U.S. Office of Research Integrity is leaving the agency. Susan Garfinkel told Retraction Watch that her last day is November 10. She is taking a position as assistant vice president in the Office of Research Compliance at The Ohio State University (OSU). Garfinkel declined to […]

    The post Division director leaving U.S. research watchdog after nearly 15 years appeared first on Retraction Watch.

    in Retraction watch on October 16, 2017 03:37 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Electrical Brain Stimulation in Treatment of Neurodegenerative Diseases

    The early Egyptians and Romans recognized the numbing effect of the electric properties of catfish. In fact, Romans were the first to cultivate electric fishes for pain relieving effect. But since then, not much has changed in the development of electricity based medical treatments. Things only started to change two millennia later with the discovery of electricity and a better understanding of neurophysiology.

    Electroconvulsive therapy was born in the middle of the 19th century. In the early days, it was primarily used to treat neuropsychiatric disorders. In the mid-19th century, direct electric current was used for electroconvulsive therapy. By the end of 19th-century, the alternate current was discovered, and its use along with the use of magnetic fields became the subject of experiments not only investigating neuropsychiatric conditions but also other diseases like epilepsy and chronic severe headaches.

    Electroconvulsive therapy is still used in the treatment of severe neuropsychiatric conditions like schizophrenia or depression, where suicidal tendencies do not respond to pharmacological agents. Unlike in the old days, now this is a non-invasive treatment usually performed under general anesthesia. The therapy non-selectively resets various centers in the brain and thus has wide-ranging side effects like loss of memory, headaches, and muscle aches.

    Considering the widespread side effects of electroconvulsive therapy, the need for more selective stimulation of particular brain centers specific for a particular disease was obvious. The improvements in understanding of brain physiology and surgical techniques gave rise to “deep brain stimulation” (DBS). This is an invasive method where electrodes are surgically placed inside the specific part of the brain that are connected to a small electrical device that generates the stimulation.

    At present, DBS has been shown to be effective in the treatment of Parkinson’s disease, epilepsy, obsessive compulsive disorder, and dystonia. It is being studied for applications in treating depression, drug addiction, and other neurodegenerative disorders such as dementia. As the method is invasive and involves the surgical implantation of electrodes inside the brain, it is reserved for cases that fail to respond to pharmacological therapy.

    Deep brain stimulation in Parkinson’s disease

    Dopamine is a chemical messenger in the brain that plays an important role in physical movement. In Parkinson’s disease, there is a progressive loss of dopamine-producing neurons resulting in motor deficiencies. Thus, the first line therapy for this disease is to give dopamine replacement therapy by prescribing a drug called levodopa.

    The problem is, one-third of cases of Parkinson’s disease progress quickly and stop responding to the therapy with levodopa or other pharmacological agents, thus necessitating a treatment like DBS.

    For the best results, it is recommended to go for DBS well before the symptoms become debilitating. In the later stages, the effectiveness of DBM tends to be lower.

    DBS in Parkinson’s disease involves the application of continuous high-frequency electrical pulses through electrodes implanted in the subthalamic nucleus (STN) in the brain (though sometimes other locations may also be chosen). The STN is demonstrated to be over-activated in Parkinson’s disease. These electrodes are connected to the compatible pulse generating device. The pulse generator uses various pulses to achieve the optimal effect, where the right kind of settings can be chosen for a person by assessing treatment effectiveness.

    Continuous DBS was shown to improve motor symptoms in more than two-thirds of patients, as compared to no stimulation or intermitted stimulation.

    In one of the clinical studies, bilateral STN DBS was performed on patients that were not responding to the maximum dose of levodopa or to a continuous infusion of apomorphine. DBS showed marked improvement in motor function in 61% of cases. After the procedure, there was a 37.1% decrease in the daily dosage of levodopa in the patients. There was an almost 70% decrease in the need for apomorphine, with some patients not requiring apomorphine at all. Thus, the effectiveness of bilateral STN DBS in advanced Parkinson’s disease is well established.

    Although the exact mechanism whereby DBS is effective is still unknown, it is believed to involve overcoming abnormal electrical patterns generated in the basal ganglia.

    With the devices and surgical technique being constantly refined,  the effectiveness of this treatment may improve sufficiently enough to be widely used during the early stages of the disease in the future.

    Deep brain stimulation in Alzheimer’s disease

    In Alzheimer’s disease, DBS is still an experimental treatment. Lots of research with the use of various techniques has been done on animals, some with positive results. In one such study in monkeys, intermittent DBS was used with 60 pulses for 20 seconds with an interval of 40 seconds in between. The experiment demonstrated improvements in the memory of the primates. The experiment also showed deterioration of memory following continuous stimulation. The differences with results in the treatment of Parkinsonism might be explained by the differing pathological mechanisms involved.

    After months of intermittent stimulation, the monkeys demonstrated improvements in memory even on discontinuation of stimulation. This lasting effect has not yet been explained. It is quite possible that such intermittent stimulation results in an improved connection between neurons, or higher levels of release of the neurotransmitter acetylcholine.

    DBS has certain benefits over drugs, as it stimulates specific areas of the brain, while anticholinergic drugs used to treat Alzheimer’s have widespread non-selective action. Thus, DBM may prove to be a safer treatment option in the future.

    It has to be noted that apart from DBS, non-invasive neurostimulation using transcranial magnetic stimulation has also demonstrated promising effects in animal studies.


    Dubljevi?, V., Saigle, V., Racine, E., 2014. The Rising Tide of tDCS in the Media and Academic Literature. Neuron 82, 731–736. doi:10.1016/j.neuron.2014.05.003.

    Elder, G.J., Taylor, J.-P., 2014. Transcranial magnetic stimulation and transcranial direct current stimulation: treatments for cognitive and neuropsychiatric symptoms in the neurodegenerative dementias? Alzheimers Res. Ther. 6, 74. doi:10.1186/s13195-014-0074-1.

    Green, A.L., Bittar, R.G., Bain, P., Scott, R.B., Joint, C., Gregory, R., Aziz, T.Z., 2006. STN vs. Pallidal Stimulation in Parkinson Disease: Improvement with Experience and Better Patient Selection: STN vs. Pallidal DBS. Neuromodulation Technol. Neural Interface 9, 21–27. doi:10.1111/j.1525-1403.2006.00038.x.

    Hansen, N., 2014. Brain Stimulation for Combating Alzheimer’s Disease. Front. Neurol. 5. doi:10.3389/fneur.2014.00080.

    Little, S., Pogosyan, A., Neal, S., Zavala, B., Zrinzo, L., Hariz, M., Foltynie, T., Limousin, P., Ashkan, K., FitzGerald, J., Green, A.L., Aziz, T.Z., Brown, P., 2013. Adaptive deep brain stimulation in advanced Parkinson disease. Ann. Neurol. 74, 449–457. doi:10.1002/ana.23951.

    Mallet, L., 2010. Deep Brain Stimulation in Psychiatric Disorders, in: Koob, G.F., Moal, M.L., Thompson, R.F. (Eds.), Encyclopedia of Behavioral Neuroscience. Academic Press, Oxford, pp. 376–381. doi:10.1016/B978-0-08-045396-5.00249-9.

    Sharifi, M.S., 2013. Treatment of Neurological and Psychiatric Disorders with Deep Brain Stimulation; Raising Hopes and Future Challenges. Basic Clin. Neurosci. 4, 266–270. PMCID: PMC4202568.

    Varma, T.R.K., Fox, S.H., Eldridge, P.R., Littlechild, P., Byrne, P., Forster, A., Marshall, A., Cameron, H., McIver, K., Fletcher, N., Steiger, M., 2003. Deep brain stimulation of the subthalamic nucleus: effectiveness in advanced Parkinson’s disease patients previously reliant on apomorphine. J Neurol Neurosurg Psychiatry 74, 170–174. doi:10.1136/jnnp.74.2.170.

    Image via PublicDomainPictures/Pixabay.

    in Brain Blogger on October 16, 2017 03:30 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Neutron star collision showers the universe with a wealth of discoveries

    A collision of neutron stars was spotted with gravitational waves for the first time. Telescopes captured gamma rays, visible light and more from the smashup.

    in Science News on October 16, 2017 02:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Caught Our Notice: Investigation finds “accidental mistakes” in PNAS stem cell paper

    When Retraction Watch began in 2010, our co-founders Ivan Oransky and Adam Marcus quickly realized they couldn’t keep up with the hundreds of retractions that appeared each year.  And the problem has only gotten worse — although we’ve added staff, the number of retractions issued each year has increased dramatically. According to our growing database, […]

    The post Caught Our Notice: Investigation finds “accidental mistakes” in PNAS stem cell paper appeared first on Retraction Watch.

    in Retraction watch on October 16, 2017 12:30 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    36 hours of hacking medicine at Johns Hopkins MedHacks 2017

    Students we mentored created apps to prevent bed sores and remind you when to take your meds

    in Elsevier Connect on October 16, 2017 09:19 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    How researchers are using NLP and machine learning to ease your information overload

    Elsevier teams are working with academic researchers to use technology to improve scholarly communication

    in Elsevier Connect on October 16, 2017 09:01 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Find a gym buddy – not letting them down can be a powerful incentive

    GettyImages-668194250.jpgBy guest blogger Juliet Hodges

    Spreading information about the benefits of exercise – including how it reduces the risk of chronic diseases and improves mental health and wellbeing, from sleep quality to self-esteem – hasn’t been enough to change people’s behaviour. Only 30 to 40 per cent of adults in the UK say they get the recommended amount of physical activity per week, and this figure drops to just 5 per cent when using accelerometers to measure movement. It’s a similar story even for people who have made the effort to join a gym – in a recent poll, a third of members reported visiting their gym three times a year or less. It seems we need to get more creative to persuade people to get active.

    To test out some innovative psychological approaches, a new study published in the Journal of Behavioral and Experimental Economics selected 181 infrequent gym-goers at the University of West Chester, who went on average less than once a week before the experiment. All students at the university have free access to the fitness centre, and their attendance is automatically recorded when they swipe in.

    The researchers tested three types of intervention, in isolation or combined, over the course of three weeks. First was the financial incentive: everyone (except the control group) was entered into a lottery, with a chance to win an $80 Amazon voucher if they met their weekly exercise goal of three 30-minute sessions. Second, some participants were partnered up, and were only eligible for the lottery if both members of the team had met the goal. Finally, half of the participants were given information midweek about how many other individuals or teams had already reached the weekly target. In all, there were five participant groups: the control, individuals with information (about others’ attendance), individuals without information, teams with information and teams without information.

    The lottery increased gym attendance in all groups during the study from their pre-experiment average of less than once a week. Individuals enrolled in the lottery on their own, but without information about others, more than doubled their attendance to almost 1.5 visits per week, although this effect was not statistically significant. The individuals enrolled in the lottery on their own and who also had access to information about other people’s behaviour increased their visits to almost twice per week. The most impressive result was for the participants enrolled in the lottery in a two-person team – whether they had access to information about other people’s behaviour or not, they tripled their average visit rate to more than three times per week.

    The researchers also monitored behaviour for several weeks after the experiment. All groups kept going to the gym slightly more than they had done before the experiment, particularly the individuals with information. Looking specifically at non-users, defined as those who had not used the gym at all in the four weeks before the study, the researchers found that 80 per cent went at least once during and once after the intervention. Furthermore, non gym-users who received information were more likely to keep going than other groups. However, none of the interventions had a lasting effect beyond the Thanksgiving break four weeks after the experiment finished.

    It is not entirely surprising that the lottery alone was less motivating than being in a team or receiving information. Financial incentives or penalties aren’t always the best way to change behaviour; as most of us know, paying for a gym membership is no guarantee you’ll actually go. However, other studies using financial rewards for exercise have found better uptake and maintenance even after they were removed. The less impressive results in the current study could be due to a number of reasons, such as the short duration of the experiment, the relatively small amount of money, or the reward being a lottery rather than a guaranteed amount.

    Participants in teams exercised most frequently during the experiment, which is consistent with research in a range of domains that finds people are more motivated when others are also relying on them. The researchers didn’t indicate whether participants were introduced to their teammates, which can make these interventions more effective. People are less willing to disappoint people they know, so friends increase each other’s attendance when they are paired up, while an anonymous partner can be less effective than an individual incentive.

    The mechanism behind the effectiveness of the information intervention is unclear. It could simply have acted as a reminder for people to squeeze three sessions in, prompting a spike in attendance towards the end of the week. The researchers suggest that knowing what others were doing could have made the lottery prize seem more accessible, as very few had completed three sessions by midweek. This seems more likely than a social norm explanation, which would assume the low numbers would reduce motivation.

    It would be unwise to draw too many conclusions from this study, particularly given its short duration and limited sample size. It does however suggest that information and team dynamics, together or in isolation, can be cost-effective, easy-to-deliver ways to promote physical activity.  For example, gyms could trial providing feedback on how many members had attended that week – although they may be unwilling to do so, given their business models often rely on people paying but not turning up.

    Get thee to the gym! A field experiment on improving exercise habits

    Juliet Hodges photo
    Post written for the BPS Research Digest by Juliet Hodges. Juliet has a background in psychology and behavioural economics, and has applied this in advertising and now healthcare. Follow @hulietjodges on TwitterLinkedIn or read her posts for the Bupa Newsroom here.

    in The British Psychological Society - Research Digest on October 16, 2017 08:54 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    A Parade of Scientific Mice

    Recently I was reading a neuroscience paper and was struck by the cuteness of the two mice that formed part of Figure 1: So I decided to look further and collect a montage of scientific mice. All of these drawings are taken from peer-reviewed scientific papers. As you can see, the styles vary greatly. Some mice are little more than circles with ears, while others look ready to leap off the page in search of cheese: I should note that I didn't include mice found in Graphical Abstrac

    in Discovery magazine - Neuroskeptic on October 15, 2017 07:07 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Is Parkinson's A Prion Disease?

    The Journal of Neuroscience recently featured a debate over the hypothesis that Parkinson's disease is, at least in some cases, caused by a prion-like mechanism - misfolded proteins that spread from neuron to neuron. A prion is a protein that has taken on an abnormal shape and that can spread itself by making other, healthy molecules of the same protein adopt its abnormal configuration. The best-known prion disease is variant CJD aka "mad cow disease", but some researchers believe that Pa

    in Discovery magazine - Neuroskeptic on October 14, 2017 07:45 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Weekend reads: Systemic fraud in China; science without journals; authorship rules decay

    The week at Retraction Watch featured the retraction of a paper that had been called “anti-vaccine pseudoscience,” a retraction following threats of violence against an editor, and an editorial board member’s resignation over how a journal handled a case of plagiarism. Here’s what was happening elsewhere: “Now, a recent string of high-profile scandals over questionable […]

    The post Weekend reads: Systemic fraud in China; science without journals; authorship rules decay appeared first on Retraction Watch.

    in Retraction watch on October 14, 2017 02:24 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    When the Larsen C ice shelf broke, it exposed a hidden world

    Scientists plan urgent missions to visit the world the Larsen C iceberg left behind.

    in Science News on October 13, 2017 05:33 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Detrimental Effects of Bright Screens on Sleep Patterns

    We often complain about people around us constantly being glued to their phone. Mobile technology is everywhere these days. When not on the go, we still tend to stare at computer screens both in the office and back at home. For many, this addiction to high-tech devices represents a way to be connected to friends and family. Many others think that these devices isolate us from real interaction with the world around us. One way or another, we do indeed spend too much time with our computers, laptops, tablets, and smartphones.

    Apart from changing the way we communicate (for better or worse), all these devices have one more thing in common: bright screens. These light emitting screens can seriously affect our sleeping pattern. Moreover, the blue light (of a wavelength of ~470 nm) that is emitted by these devices is particularly harmful to normal sleep.

    These days, an increasingly large number of people report problems with sleeping. Many people can’t fall asleep in the evening and then do not feel refreshed the next morning when they have to go to work. Lots of people complain about disturbed shallow sleeping and frequent awakenings at night. With normal sleeping hours often affected, people sleep less at night and if they can, compensate for this lack of sleep with daytime naps.

    Disturbed sleep patterns are often linked to a diminished ability to focus on work, lack of motivation, and a generally low mood. This may lead to conflicts and stress at the workplace resulting, in some cases, in anxiety and depression. There are long-term negative consequences for other organs and systems of the body too. For instance, the link between chronically bad sleep and cardiovascular problems is well documented. Sleeping pattern disturbances also contribute to excessive body weight. It is estimated that around half of all Americans suffer from chronic stress at moderate or severe levels. Disturbingly, this number is growing in recent years.

    Apart from many social and psychological factors, the growing level of stress in the general population can also be linked to the growing and excessive use of computers and smartphones. Exposure to bright screens in the evening hours is particularly harmful.

    Our circadian rhythm (the sleep-wake pattern) is regulated by our exposure to light. There are several components of this system that are particularly important. First, we have specific cells in our eye retina that function as detectors of the duration and intensity of light. These cells, called intrinsically photosensitive retinal ganglion cells (ipRGCs), are particularly sensitive to short wavelength blue light.

    Light-exposed ipRGC cells send signals to the suprachiasmatic nucleus in the brain. This region is responsible for setting the body clock, achieved by regulating the production of the hormone melatonin in the pineal gland. Melatonin plays a role in the adjusting mechanism: it synchronizes the body’s circadian rhythms with the real-life cycle of day and night experienced by the body. The problem is, this system can be easily fooled by prolonged exposure to artificial light. When you stare at your laptop screen late in the evening, you are also sending a signal to your brain that you are currently experiencing daytime. Your body will try to adjust accordingly to help you take advantage of daytime hours—it will reduce your desire to sleep. And once the screen is off, you don’t feel like sleeping anymore…

    Recently published experimental data demonstrated that just two hours of evening exposure to bright computer screens emitting blue light decreases sleep duration and, more importantly, dramatically reduces its quality. People exposed to computer screens were awakening during the night much more often compared to those who did not use computers in the evening. The data also demonstrated that both the type of light emitted by the screens and its intensity is important for nighttime sleep quality. The screens with low brightness were less disturbing for sleep quality, and the screens emitting red light did not affect nighttime sleep at all.

    Exposure to blue light-emitting bright screens in the morning is actually a positive thing: it can help to readjust the body to the correct time of the day. In fact, morning exposure to blue light is even used in a number of bright light therapy methods aimed at normalizing the circadian cycle, particularly in elderly people who often experience sleep-wake pattern disturbances.

    It is quite unlikely that after reading this article anyone will immediately give up the habit of late-night internet browsing or chatting with friends via social networks before going to sleep. There are, however, several simple methods to reduce evening exposure to blue light emitted by screens. First, you can reduce the brightness of your screen. You can also change the background color while reading some types of documents. Text with white letters on a black background definitely reduces light exposure. If you anticipate working with documents in the evening, it might be a good idea to print them out. Paper is certainly much friendlier to the eyes. It is also possible to cover your computer screens with special filters that block out blue light. These small changes won’t require any major changes to your habits and routine but will help you to regain a normal sleep-wake pattern and bolster feeling refreshed the next day.


    Arendt J. (2006) Melatonin and human rhythms. Chronobiol Int. 23(1-2): 21-37. DOI: 10.1080/07420520500464361.

    Figueiro, M.G., Wood, B., Plitnick, B. et al. (2011) The impact of light from computer monitors on melatonin levels in college students. Neuro Endocrinol Lett. 32(2):158-63. PMID: 21552190.

    Skene DJ, Arendt J. (2006) Human circadian rhythms: physiological and therapeutic relevance of light and melatonin. Ann Clin Biochem. 43(Pt 5): 344-53. DOI: 10.1258/000456306778520142.

    Wright HR, Lack LC, Kennaway DJ. (2004) Differential effects of light wavelength in phase advancing the melatonin rhythm. J Pineal Res. 36(2): 140-4. DOI: 10.1046/j.1600-079X.2003.00108.x.

    Image via simonwijers/Pixabay.

    in Brain Blogger on October 13, 2017 03:30 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Are rich people meaner? While trying to find out, two teams find errors in each other’s work

    Is having money linked to bad behavior? A high profile paper published in 2012 in the Proceedings of the National Academy of Sciences (PNAS) set out to answer that question — and found that yes, the more money people have, the more likely they are to lie, cheat, and steal. And the greedier they are, […]

    The post Are rich people meaner? While trying to find out, two teams find errors in each other’s work appeared first on Retraction Watch.

    in Retraction watch on October 13, 2017 02:11 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    11th International Conference on Behavior, Physiology and Genetics of Wildlife

    The conference started with a plenary by Cheryl Asa from the AZA Reproductive Management Center at Saint Louis Zoo. Reproduction in zoos is important to maintain captive populations without importing animals from the wild. Cheryl spoke on the evolving role of reproductive biology in zoos including its challenges such as genetic health, mate incompatibility and female infertility.

    Other interesting talks on the first day focused on wolf conservation in Portugal, the restoration of the North Persian leopard population in the Russian Caucasus and snaring of spotted hyenas in the Serengeti. Annika Tiesmeyer’s research on the assessment of the conservation status through a clever monitoring technique on the example of the European wildcat was a nice example of a citizen science project where average citizens helped by collecting wildcat DNA from valerian-treated hair traps.

    The second day was opened with an excellent plenary talk by Steven R. Beissinger from the University of California on the climate and land-use impacts on the metacommunity dynamics of California birds and mammals. A key aspect of Steven’s talk was the importance of linking the past to the future on the example of the pen and paper notes by Joseph Grinnell and his colleagues. Steven and his team resampled historical biodiversity surveys of Grinnell originally surveyed for birds and mammals from 1908-1939 to understand the influence of 20th century environmental changes on biodiversity. In this context, Steven stressed that one day the notes we take today will be historic and highlighted the importance of data preservation. Incidentally, our sister journal BMC Research Notes has recently launched data notes with the goal to support researchers with good data practice and to preserve valuable research data.

    Someday your data will be historic. How will you preserve it?

    Steven R. Beissinger

    During the 2nd poster session in one of the impressive glasshouses of the Berlin Botanical Garden, thunderstorm “Xavier” reached full strength and forced delegates to stay inside. The organizers’ talent for improvisation came to light as delegates could not come to the talks; the talks were brought to the delegates. Daniel Blumenstein opened the session with an excellent overview of his work on social relationships in marmots. An interesting take away message was that meaningful social relationships can buffer stress and enhance security in marmots – perhaps something for all of us to remember!

    Another fantastic plenary talk was delivered on the final day by Klaus-Peter Koepfli from the Smithsonian Conservation Biology Institute National Zoological Park. In his talk, Klaus-Peter Koepfli provided an overview of a program to develop and apply data derived from whole genome sequences to the management of ex situ population of endangered species, specifically the sable anteleope and the black-footed ferret.

    BMC sponsored the conference and the winner and runner-up of the poster competition received a full and half-waiver of the article processing charge for a publication in a BMC series journal. Iris Tarmann won the prize for best poster with her work on the impact of global warming on hibernation of garden dormice. Jessica Svea Cornils was a close second by popular vote with her work on why edible dormice prefer areas with diverse tree species to optimize survival and reproduction.

    Credit: Leibniz-IZW.

    Following the closing session, delegates were invited to a guided tour through the Leibniz-IZW. As an internationally respected research institution, the Leibniz-IZW conducts research on the evolutionary adaptation of wildlife populations and develops new concepts and measures for wildlife conservation with a focus on mammals. A highlight of the tour was the presentation of the cutting-edge CT scanner in veterinary medicine by Guido Fritsch which can be used for large cats and has even seen famous Berlin polar bear Knut following his unexpected death in 2011.

    The BPG conference organized every two years by the IZW and EAZA is a small but fantastic conference that researchers working on the behavior, physiology and genetics of wildlife animals will enjoy. BMC Zoology was impressed with the line-up of high quality plenary speakers and we would be delighted to visit Berlin again in two years.

    The post 11th International Conference on Behavior, Physiology and Genetics of Wildlife appeared first on BMC Series blog.

    in BMC Series blog on October 13, 2017 01:17 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    Surgeon aims to diagnose deformities of extinct saber-toothed cats

    Using CT scans, one orthopedic surgeon is on a quest to diagnose deformities in long-dead saber-toothed cats.

    in Science News on October 13, 2017 01:00 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    An accomplished philosopher invented a pseudonym. Why?

    In 1980, Leila Tov-Ruach published a book chapter in which she thanked the editor of the book, Amélie Oksenberg Rorty, “for the hospitality that made the writing of this paper possible.” Normally, such an acknowledgement wouldn’t raise eyebrows. But, the trouble is, Tov-Ruach and Rorty are the same person:  Leila Tov-Ruach is a pseudonym for […]

    The post An accomplished philosopher invented a pseudonym. Why? appeared first on Retraction Watch.

    in Retraction watch on October 13, 2017 12:15 PM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    An American astronomical evangelist coined the phrase ‘island universe’

    Ormsby MacKnight Mitchel, a Civil War general nicknamed ‘Old Stars,’ first used ‘island universe’ in his monthly astronomy magazine.

    in Science News on October 13, 2017 11:00 AM.

  • Wallabag.it! - Save to Instapaper - Save to Pocket -

    A hazardous undertaking: how ant queens prevent disease during colony foundation

    When most people think of an ant queen, they are likely to have an image of a monarch, tended to and protected by her daughters, the sterile workers. Unlike the workers, which carry out all the hard and dangerous tasks, the queen is kept safe, deep within a subterranean bunker that is her nest. There she will live, for perhaps as long as several decades (the current record being about 30 years), laying hundreds of eggs every day, whilst being fed and cleaned by a retinue of workers.

    However, life for an ant queen does not typically start out this way. In fact, the majority of queens are likely to die before they have even raised their first batch of workers. This is because new queens, produced by mature ant colonies, must leave the parental nest to found new ones.

    It is estimated that less than 1% of queens actually survive beyond their first year.

    Many founding queens fall prey to birds, spiders and the workers of other colonies during the process, as well as contracting bacterial and fungal infections from the soil that cause disease and death. Moreover, because they do not forage, they must breakdown their own body tissue in order to feed themselves and their brood until their workers emerge, making starvation a likely possibility.

    Young colonies are also at risk of being raided by larger ones, which will steal their brood and kill the queen. As a consequence, it is estimated that less than 1% of queens actually survive beyond their first year.

    A joint venture

    To improve their chances of survival, some queens will found a colony with unrelated queens from other nests. Termed co-founding, this behaviour is thought to be beneficial as a pair of queens may raise more workers faster than a single queen, potentially giving them a competitive edge. Yet, the exact reasons behind co-founding are up for debate and it may simply be the result of overcrowding and competition for the best nest sites.

    Co-founding still has its drawbacks, however, since the queens fight to the death for control of the nest once it has workers. Additionally, before this, co-founding may increase a queen’s risk of infection if her co-founder falls sick and dies. In mature colonies, dead and/or infected nest mates are quickly removed from the nest, or destroyed by the workers. These “undertaking” behaviours keep the nest clean and prevent diseases from spreading. In the absence of workers, how do co-founding queens overcome this problem?

    A dead queen infected with the pathogenic fungus Metarhizium. The green “blocks” are dense packages of infectious fungal spores.

    We set out to answer this question in our recent BMC Evolutionary Biology article, using queens of the common black garden ant and a generalist fungal pathogen. In our first experiment, we carried out a choice test, to see whether queens, faced with the choice of founding a colony alone or with a queen carrying infectious fungal spores on her body, avoid the pathogen-exposed queen. As a control, another set of queens could choose to found alone or with a sham-treated queen.

    Despite the risk of nesting with a pathogen-exposed queen, we found co-founding to be high (about 60%) in all of our treatment groups, suggesting that the avoidance of pathogen-exposed queen is not a mechanism queens use to reduce their risk of contracting infections from co-founders.

    In a second experiment, we paired queens with either a pathogen-exposed or sham-treated queen, in either closed or open nests ­­– the latter having a hole that opens to a small arena. Once the pathogen-exposed queens started dying of infections, we freeze-killed the queens in the control group to see how the surviving queens react to both infected and uninfected corpses.

    Freshly collected founding queens were painted for identification in experiments.
    Freshly collected founding queens were painted for identification in experiments.

    Strange undertakings

    We found that the surviving queens performed undertaking behaviours. Namely, corpses were bitten into pieces and buried, or, in the open nests, removed from the nest entirely.

    We found that the surviving queens performed undertaking behaviours. Namely, corpses were bitten into pieces and buried, or, in the open nests, removed from the nest entirely. Interestingly, although queens carried out these behaviours before the fungal pathogen became infectious (grew out of the corpse), it seems unlikely that the queens are responding directly to the presence of an infection, because the uninfected corpses were treated exactly the same.

    Queens therefore seem to perform undertaking behaviour prophylactically, i.e. before there are any signs of disease on the corpse. From the perspective of the queen, it makes sense to treat all corpses as equally risky, because waiting until the pathogen grows out may be too late to prevent disease transmission. Indeed, we found that biting the corpses into pieces and burying them significantly reduced the risk of the queens contracting a lethal infection from the corpse when the fungus did grow out, presumably because burial prevents transmission of the fungal spores. In other words, performing undertaking behaviours improved founding queen survival.

    Our work shows that, in contrast to the typical view of ant queens focussing solely on reproduction and avoiding all risky tasks, queens can perform complex behaviours to protect themselves when they lack workers to do so for them. In fact, there are some ant queens, considered to be more evolutionarily basal species, which still forage during colony foundation. Furthermore, queens that fail to mate and remain in their parental nest begin behaving like workers, and will even forage outside of the nest.

    Understanding this behavioural flexibility, and its underlying genetic mechanisms, could provide an interesting insight into what makes a queen a queen, and the evolution of separate queen and worker castes in the social insects.

    The post A hazardous undertaking: how ant queens prevent disease during colony foundation appeared first on BMC Series blog.

    in BMC Series blog on October 13, 2017 08:30 AM.