Being a selfish jerk doesn't get you ahead: Study

 The evidence is in: Nice guys and gals don't finish last, and being a selfish jerk doesn't get you ahead.

That's the clear conclusion from research that tracked disagreeable people from college or graduate school to where they landed in their careers about 14 years later.

"I was surprised by the consistency of the findings. No matter the individual or the context, disagreeableness did not give people an advantage in the competition for power -- even in more cutthroat, 'dog-eat-dog' organizational cultures," said Berkeley Haas Prof. Cameron Anderson, who co-authored the study with Berkeley Psychology Prof. Oliver P. John, doctoral student Daron L. Sharps, and Assoc. Prof. Christopher J. Soto of Colby College.

The paper was published August 31 in the Proceedings of the National Academy of Sciences.

The researchers conducted two studies of people who had completed personality assessments as undergraduates or MBA students at three universities. They surveyed the same people more than a decade later, asking about their power and rank in their workplaces, as well as the culture of their organizations. They also asked their co-workers to rate the study participants' rank and workplace behavior. Across the board, they found those with selfish, deceitful, and aggressive personality traits were not more likely to have attained power than those who were generous, trustworthy, and generally nice.

That's not to say that jerks don't reach positions of power. It's just that they didn't get ahead faster than others, and being a jerk simply didn't help, Anderson said. That's because any power boost they get from being intimidating is offset by their poor interpersonal relationships, the researchers found. In contrast, the researchers found that extroverts were the most likely to have advanced in their organizations, based on their sociability, energy, and assertiveness -- backing up prior research.

"The bad news here is that organizations do place disagreeable individuals in charge just as often as agreeable people," Anderson said. "In other words, they allow jerks to gain power at the same rate as anyone else, even though jerks in power can do serious damage to the organization."

The age-old question of whether being aggressively Machiavellian helps people get ahead has long interested Anderson, who studies social status. It's a critical question for managers, because ample research has shown that jerks in positions of power are abusive, prioritize their own self-interest, create corrupt cultures, and ultimately cause their organizations to fail. They also serve as toxic role models for society at large.

For example, people who read former-Apple CEO Steve Jobs' biography might think, "Maybe if I become an even bigger asshole I'll be successful like Steve," the authors note in their paper. "My advice to managers would be to pay attention to agreeableness as an important qualification for positions of power and leadership," Anderson said. "Prior research is clear: agreeable people in power produce better outcomes."

While there's clearly no shortage of jerks in power, there's been little empirical research to settle the question of whether being disagreeable actually helped them get there, or is simply incidental to their success. Anderson and his co-authors set out to create a research design that would clear up the debate.

What defines a jerk? The participants had all completed the Big Five Inventory (BFI), an assessment based on general consensus among psychologists of the five fundamental personality dimensions: openness to experience, conscientiousness, extraversion, neuroticism, and agreeableness. It was developed by Anderson's co-author John, who directs the Berkeley Personality Lab. In addition, some of the participants also completed a second personality assessment, the NEO Personality Inventory-Revised (NEO PI-R).

"Disagreeableness is a relatively stable aspect of personality that involves the tendency to behave in quarrelsome, cold, callous, and selfish ways," the researchers explained. ." ..Disagreeable people tend to be hostile and abusive to others, deceive and manipulate others for their own gain, and ignore others' concerns or welfare."

In the first study, which involved 457 participants, the researchers found no relationship between power and disagreeableness, no matter whether the person had scored high or low on those traits. That was true regardless of gender, race or ethnicity, industry, or the cultural norms in the organization.

The second study went deeper, looking at the four main ways people attain power: through dominant-aggressive behavior, or using fear and intimidation; political behavior, or building alliances with influential people; communal behavior, or helping others; and competent behavior, or being good at one's job. They also asked the subjects' co-workers to rate their place in the hierarchy, as well as their workplace behavior (interestingly, the co-workers' ratings largely matched the subjects' self-assessments).

This allowed the researchers to better understand why disagreeable people do not get ahead faster than others. Even though jerks tend to engage in dominant behavior, their lack of communal behavior cancels out any advantage their aggressiveness gives them, they concluded.

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Nature conservation policy rarely changes people's behavior

 It is a well-known problem: too rarely do nature conservation initiatives, recommendations or strategies announced by politicians lead to people really changing their everyday behaviour. A German-Israeli research team led by the Helmholtz Centre for Environmental Research (UFZ) and the German Centre for Integrative Biodiversity Research (iDiv) has investigated the reasons for this. According to the team, the measures proposed by politicians do not sufficiently exploit the range of possible behavioural interventions and too rarely specify the actual target groups, they write in the journal Conservation Biology.

The protection of pollinating insects is a major issue in international nature conservation policy. Stirred up by scientific findings on high population losses of insect groups such as bees or butterflies, which, for example, affect pollination services in agriculture, Europe is putting insect protection at the forefront of environmental policy. Many governments in Europe have presented national strategies to ensure that pollinators are maintained. A team of researchers from UFZ, iDiv and Technion -- Israel Institute of Technology analysed the available eight national strategy papers to protect pollinators in terms of behavioural change interventions. The result: "Nature conservation policies to preserve pollinators are often too ineffective in this respect and change little in people's behaviour," says first author and environmental psychologist Dr. Melissa Marselle, who is conducting research at the UFZ and iDiv on the impact of biodiversity on human health.

The scientists coded around 610 behavioural measures in the strategy papers. Using the "Behaviour Change Wheel" theory, which originates from health psychology and integrates 19 different behavioural models, the scientists categorized the behavioural measures for pollinator conservation into the nine different types of interventions -- i.e. measures that could change people's behaviour. According to this, most of the 790 or so behavioral measures for pollinator conservation (23 percent) can be assigned to the behaviour change interventions of education and awareness raising, followed by structural measures such as planting hedges, sowing flower strips in fields or creating green spaces in the city (19 percent). Only around four percent of the behavioural measures for pollinator conservation can be summarized under the intervention of modeling, for example, peer-to-peer learning or the use of best-practice examples from farmers who work in exemplary fashion. Other little-mentioned behavioural interventions for pollinator conservation were incentive systems for farmers or municipalities (three percent) and statutory regulations (two percent). Interventions that create a financial cost to discourage a certain behaviour, such as additional taxes on the use of pesticides, did not appear in any of the policy papers for pollinator conservation.

"This shows that national biodiversity strategies focus primarily on educational and structural measures and neglect other effective instruments," says Melissa Marselle. "Educational measures to impart knowledge and to create understanding are important. But relying on education alone is not very effective if you really want to change environmental behaviour. It would be more effective to link it to a wider range of other measures." For example, clearly identifying supply chains and producer principles on labels can encourage many people to buy an organic or pollinator-friendly products -- even at a higher price. Stronger financial incentives for farmers who operate sustainably would also be effective, and the certification of sustainable buildings could be linked to the use of pollinator-friendly plants as flower beds. Taxes and additional costs for consumers also ensure rapid changes in behaviour: In the UK, for example, a compulsory levy on the purchase of plastic bags has led to a decline in their use.

A further shortcoming of the strategy papers was identified as the fact that in 41 percent of the behavioural measures for pollinator conservation the target groups whose behaviour needs to change were not named and specified. The objectives are often very well described, but mostly revolve around the question of how certain actions change the environment. However, it is often not defined in more detail to whom the actions are directed and who should implement them: the public, farmers or local authorities? It could be more effective to first consider what the different actors can do, with the help of behavioural researchers, and then, building on that, to consider measures to achieve certain goals.

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Face shield or face mask to stop the spread of COVID-19?

 If the United States Centers for Disease Control and Prevention (CDC) guidelines aren't enough to convince you that face shields alone shouldn't be used to stop the spread of COVID-19, then maybe a new visualization study will.

To increase public awareness about the effectiveness of face shields alone as well as face masks with exhalation valves, researchers from Florida Atlantic University's College of Engineering and Computer Science used qualitative visualizations to test how face shields and masks with valves perform in impeding the spread of aerosol-sized droplets. Widespread public use of these alternatives to regular masks could potentially have an adverse effect on mitigation efforts.

For the study, just published in the journal Physics of Fluids, researchers employed flow visualization in a laboratory setting using a laser light sheet and a mixture of distilled water and glycerin to generate the synthetic fog that made up the content of a cough-jet. They visualized droplets expelled from a mannequin's mouth while simulating coughing and sneezing. By placing a plastic face shield and an N95-rated face mask with a valve, they were able to map out the paths of droplets and demonstrate how they performed.

Results of the study show that although face shields block the initial forward motion of the jet, the expelled droplets move around the visor with relative ease and spread out over a large area depending on light ambient disturbances. Visualizations for the face mask equipped with an exhalation port indicate that a large number of droplets pass through the exhale valve unfiltered, which significantly reduces its effectiveness as a means of source control.

"From this latest study, we were able to observe that face shields are able to block the initial forward motion of the exhaled jet, however, aerosolized droplets expelled with the jet are able to move around the visor with relative ease," said Manhar Dhanak, Ph.D., department chair, professor, and director of SeaTech, who co-authored the paper with Siddhartha Verma, Ph.D., lead author and an assistant professor; and John Frankenfeld, a technical professional, all within FAU's Department of Ocean and Mechanical Engineering. "Over time, these droplets can disperse over a wide area in both lateral and longitudinal directions, albeit with decreasing droplet concentration."

To demonstrate the performance of the face shield, researchers used a horizontal laser sheet in addition to a vertical laser sheet revealing how the droplets cross the horizontal plane. Not only did the researchers observe forward spread of the droplets, they found that droplets also spread in the reverse direction. Notably, face shields impede forward motion of the exhaled droplets to some extent, and masks with valves do so to an even lesser extent. However, once released into the environment, the aerosol-sized droplets get dispersed widely depending on light ambient disturbances.

Like the N-95-rated face mask used in this study, other types of masks such as certain cloth-based masks that are available commercially also come equipped with one to two exhale ports, located on either side of the facemask. The N95-rated face mask with the exhale valve used in this study had a small amount of exhaled droplets that escaped from the gap between the top of the mask and the bridge of the nose. Moreover, the exhalation port significantly reduced the effectiveness of the mask as a means of source control, as a large number of droplets passed through the valve unfiltered and unhindered.

"There is an increasing trend of people substituting regular cloth or surgical masks with clear plastic face shields as well as using masks that are equipped with exhalation valves," said Verma. "A driving factor for this increased adoption is better comfort compared to regular masks. However, face shields have noticeable gaps along the bottom and the sides, and masks with exhalation ports include a one-way valve which restricts airflow when breathing in, but allows free outflow of air. The inhaled air gets filtered through the mask material, but the exhaled breath passes through the valve unfiltered."

The researchers say that the key takeaway from this latest study illustrates that face shields and masks with exhale valves may not be as effective as regular face masks in restricting the spread of aerosolized droplets. Despite the increased comfort that these alternatives offer, they say it may be preferable to use well-constructed, high quality cloth or surgical masks that are of a plain design, instead of face shields and masks equipped with exhale valves. Widespread public adoption of the alternatives, in lieu of regular masks, could potentially have an adverse effect on ongoing mitigation efforts against COVID-19.

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Sea level rise from ice sheets track worst-case climate change scenario

 Ice sheets in Greenland and Antarctica whose melting rates are rapidly increasing have raised the global sea level by 1.8cm since the 1990s, and are matching the Intergovernmental Panel on Climate Change's worst-case climate warming scenarios.

According to a new study from the University of Leeds and the Danish Meteorological Institute, if these rates continue, the ice sheets are expected to raise sea levels by a further 17cm and expose an additional 16 million people to annual coastal flooding by the end of the century.

Since the ice sheets were first monitored by satellite in the 1990s, melting from Antarctica has pushed global sea levels up by 7.2mm, while Greenland has contributed 10.6mm. And the latest measurements show that the world's oceans are now rising by 4mm each year.

"Although we anticipated the ice sheets would lose increasing amounts of ice in response to the warming of the oceans and atmosphere, the rate at which they are melting has accelerated faster than we could have imagined," said Dr Tom Slater, lead author of the study and climate researcher at the Centre for Polar Observation and Modelling at the University of Leeds.

"The melting is overtaking the climate models we use to guide us, and we are in danger of being unprepared for the risks posed by sea level rise."

The results are published today in a study in the journal Nature Climate Change. It compares the latest results from satellite surveys from the Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) with calculations from climate models. The authors warn that the ice sheets are losing ice at a rate predicted by the worst-case climate warming scenarios in the last large IPCC report.

Dr Anna Hogg, study co-author and climate researcher in the School of Earth and Environment at Leeds, said: "If ice sheet losses continue to track our worst-case climate warming scenarios we should expect an additional 17cm of sea level rise from the ice sheets alone. That's enough to double the frequency of storm-surge flooding in many of the world's largest coastal cities."

So far, global sea levels have increased in the most part through a mechanism called thermal expansion, which means that volume of seawater expands as it gets warmer. But in the last five years, ice melt from the ice sheets and mountain glaciers has overtaken global warming as the main cause of rising sea levels.

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Study finds missing link in the evolutionary history of carbon-fixing protein Rubisco

 A team led by researchers at the University of California, Davis, has discovered a missing link in the evolution of photosynthesis and carbon fixation. Dating back more than 2.4 billion years, a newly discovered form of the plant enzyme rubisco could give new insight into plant evolution and breeding.

Rubisco is the most abundant enzyme on the planet. Present in plants, cyanobacteria (also known as blue-green algae) and other photosynthetic organisms, it's central to the process of carbon fixation and is one of Earth's oldest carbon-fixing enzymes.

"It's the primary driver for producing food, so it can take CO2 from the atmosphere and fix that into sugar for plants and other photosynthetic organisms to use. It's the primary driving enzyme for feeding carbon into life that way," said Doug Banda, a postdoctoral scholar in the lab of Patrick Shih, assistant professor of plant biology in the UC Davis College of Biological Sciences.

Form I rubisco evolved over 2.4 billion years ago before the Great Oxygenation Event, when cyanobacteria transformed the Earth's atmosphere by producing oxygen through photosynthesis. Rubisco's ties to this ancient event make it important to scientists studying the evolution of life.

In a study appearing Aug. 31 in Nature Plants, Banda and researchers from UC Davis, UC Berkeley and the Lawrence Berkeley National Laboratory report the discovery of a previously unknown relative of form I rubisco, one that they suspect diverged from form I rubisco prior to the evolution of cyanobacteria.

The new version, called form I-prime rubisco, was found through genome sequencing of environmental samples and synthesized in the lab. Form I-prime rubisco gives researchers new insights into the structural evolution of form I rubisco, potentially providing clues as to how this enzyme changed the planet.

An invisible world

Form I rubisco is responsible for the vast majority of carbon fixation on Earth. But other forms of rubisco exist in bacteria and in the group of microorganisms called Archaea. These rubisco variants come in different shapes and sizes, and even lack small subunits. Yet they still function.

"Something intrinsic to understanding how form I rubisco evolved is knowing how the small subunit evolved," said Shih. "It's the only form of rubisco, that we know of, that makes this kind of octameric assembly of large subunits."

Study co-author Professor Jill Banfield, of UC Berkeley's earth and planetary sciences department, uncovered the new rubisco variant after performing metagenomic analyses on groundwater samples. Metagenomic analyses allow researchers to examine genes and genetic sequences from the environment without culturing microorganisms.

"We know almost nothing about what sort of microbial life exists in the world around us, and so the vast majority of diversity has been invisible," said Banfield. "The sequences that we handed to Patrick's lab actually come from organisms that were not represented in any databases."

Banda and Shih successfully expressed form I-prime rubisco in the lab using E. coli and studied its molecular structure.

Form I rubisco is built from eight core large molecular subunits with eight small subunits perched on top and bottom. Each piece of the structure is important to photosynthesis and carbon fixation. Like form I rubisco, form I-prime rubisco is built from eight large subunits. However, it does not possess the small subunits previously thought essential.

"The discovery of an octameric rubisco that forms without small subunits allows us to ask evolutionary questions about what life would've looked like without the functionality imparted by small subunits," said Banda. "Specifically, we found that form I-prime enzymes had to evolve fortified interactions in the absence of small subunits, which enabled structural stability in a time when Earth's atmosphere was rapidly changing."

According to the researchers, form I-prime rubisco represents a missing link in evolutionary history. Since form I rubisco converts inorganic carbon into plant biomass, further research on its structure and functionality could lead to innovations in agriculture production.

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Can a black hole fire up the cold heart of the Phoenix Galaxy Cluster?

 Radio astronomers have detected jets of hot gas blasted out by a black hole in the galaxy at the heart of the Phoenix Galaxy Cluster, located 5.9 billion light-years away in the constellation Phoenix. This is an important result for understanding the coevolution of galaxies, gas, and black holes in galaxy clusters.

Galaxies are not distributed randomly in space. Through mutual gravitational attraction, galaxies gather together to form collections known as clusters. The space between galaxies is not entirely empty. There is very dilute gas throughout a cluster which can be detected by X-ray observations.

If this intra-cluster gas cooled, it would condense under its own gravity to form stars at the center of the cluster. However, cooled gas and stars are not usually observed in the hearts of nearby clusters, indicating that some mechanism must be heating the intra-cluster gas and preventing star formation. One potential candidate for the heat source is jets of high-speed gas accelerated by a super-massive black hole in the central galaxy.

The Phoenix Cluster is unusual in that it does show signs of dense cooled gas and massive star formation around the central galaxy. This raises the question, "does the central galaxy have black hole jets as well?"

A team led by Takaya Akahori at the National Astronomical Observatory of Japan used the Australia Telescope Compact Array (ATCA) to search for black hole jets in the Phoenix Galaxy Cluster with the highest resolution to date. They detected matching structures extending out from opposite sides of the central galaxy. Comparing with observations of the region taken from the Chandra X-ray Observatory archive data shows that the structures detected by ATCA correspond to cavities of less dense gas, indicating that they are a pair of bipolar jets emitted by a black hole in the galaxy. Therefore, the team discovered the first example, in which intra-cluster gas cooling and black hole jets coexist, in the distant Universe.

Further details of the galaxy and jets could be elucidated through higher-resolution observations with next generation observational facilities, such as the Square Kilometre Array scheduled to start observations in the late 2020s.

From Science Daily

Astrophysics: A direct view of star/disk interactions

 A team including researchers from the Institute for Astrophysics of the University of Cologne has for the first time directly observed the columns of matter that build up newborn stars. This was observed in the young star TW Hydrae system located approximately 163 light years from Earth. This result was obtained with the Very Large Telescope Interferometer (VLTI) and its GRAVITY instrument of the European Southern Observatory (ESO) in Chile. The article 'A measure of the size of the magnetospheric accretion region in TW Hydrae' has been published in a recent issue of Nature.

The formation of stars in the Galaxy involves processes in which primordial matter such as gas and dust present in the giant molecular clouds is rapidly aggregated via gravity to form a protostar. This 'accretion' of gas occurs through the disk that forms around the newborn star and represents the major mechanism of supply of material to the growing central baby star. These so-called protoplanetary disks are one of the key ingredients to explain the formation of very diverse exoplanets that are to date frequently discovered orbiting our closest neighbours.

Based on theoretical and observational evidence, many scenarios were hypothesized to describe the mechanism of interaction between the star and the parent circumstellar disk, like for instance the funnelling and accretion of host gas onto the central star along the local magnetic field. But this could never be directly observed and proven so far with any telescope. The main reason is that the level of details of the image -- astronomers talk about angular resolution -- necessary to observe what happens very close to the star was simply out of reach. For comparison, detecting these events would be like discerning a small one-cubic meter box on the surface of the Moon. With a normal telescope, this is not possible. However, with an interferometer like the VLTI in Chile and its instrument GRAVITY, which delivers unprecedented angular resolution in the infrared, such a precise observation has now become possible. An interferometer collects and combines the light from different telescopes a few hundred meters apart, which provides the same level of accuracy as a hypothetical giant telescope with a comparable diameter.

With the contribution of members of Cologne's Institute for Astrophysics, astrophysicists from several European institutions exploited the GRAVITY instrument at the VLTI to probe the closest regions around the young solar analog TW Hydrae, which is thought to be the most representative example of what our Sun may have looked like at the time of its formation, more than 5 billion years ago. By measuring very precisely the typical angular size of the very inner gaseous regions -- using a particular infrared atomic transition of the hot hydrogen gas -- the scientists were able to directly prove that the hot gas emission was indeed resulting from magnetospheric accretion taking place very close to the stellar surface. 'This is an important milestone in our attempt to confirm the mechanisms at work in the field of star formation', said Professor Lucas Labadie, co-author of the paper. 'We now want to extend such exploration to other young stars of different nature to understand how the evolution of the circumstellar disk, the birthplace of planets, goes.' T

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How antibiotics interact

 It is usually difficult to predict how well drugs will work when they are combined. Sometimes, two antibiotics increase their effect and inhibit the growth of bacteria more efficiently than expected. In other cases, the combined effect is weaker. Since there are many different ways of combining drugs -- such as antibiotics -- it is important to be able to predict the effect of these drug combinations. A new study has found out that it is often possible to predict the outcomes of combining certain antibiotics by quantitatively characterizing how individual antibiotics work. That is the result of a joint study by Professor Tobias Bollenbach at the University of Cologne with Professor Gasper Tkacik and the doctoral researcher Bor Kavcic at the Institute of Science and Technology Austria. The paper 'Mechanisms of drug interactions between translation-inhibiting antibiotics' has been published in Nature Communications.

'We wanted to find out how antibiotics that inhibit protein synthesis in bacteria work when combined with each other, and predict these effects as far as possible, using mathematical models,' Bollenbach explained. As head of the research group 'Biological Physics and Systems Biology' at the University of Cologne, he explores how cells respond to drug combinations and other signals.

Bacterial ribosomes can gradually translate the DNA sequence of genes into the amino acid sequence of proteins (translation). Many antibiotics target this process and inhibit translation. Different antibiotics specifically block different steps of the translation cycle. The scientists found out that the interactions between the antibiotics are often caused by bottlenecks in the translation cycle. For example, antibiotics that inhibit the beginning and middle of the translation cycle have much weaker effects when combined.

In order to clarify the underlying mechanisms of drug interactions, the scientists created artificial translation bottlenecks that genetically mimic the effect of specific antibiotics. If such a bottleneck is located in the middle of the translation cycle, a traffic jam of ribosomes forms, which dissolves upon introducing another bottleneck at the beginning of the translation cycle. Using a combination of theoretical models from statistical physics and experiments, the scientists showed that this effect explains the drug interaction between antibiotics that block these translation steps.

Tobias Bollenbach concluded: 'A quantitative understanding of the effect of individual antibiotics allows us to predict the effect of antibiotic combinations without having to test all possible combinations by trial and error. This finding is important because the same approach can be applied to other drugs, enabling the development of new, particularly effective drug combinations in the long term.'

From Science Daily

Using math to examine the sex differences in dinosaurs

 Male lions typically have manes. Male peacocks have six-foot-long tail feathers. Female eagles and hawks can be about 30% bigger than males. But if you only had these animals' fossils to go off of, it would be hard to confidently say that those differences were because of the animals' sex. That's the problem that paleontologists face: it's hard to tell if dinosaurs with different features were separate species, different ages, males and females of the same species, or just varied in a way that had nothing to do with sex. A lot of the work trying to show differences between male and female dinosaurs has come back inconclusive. But in a new paper, scientists show how using a different kind of statistical analysis can often estimate the degree of sexual variation in a dataset of fossils.

"It's a whole new way of looking at fossils and judging the likelihood that the traits we see correlate with sex," says Evan Saitta, a research associate at Chicago's Field Museum and the lead author of the new paper in the Biological Journal of the Linnean Society. "This paper is part of a larger revolution of sorts about how to use statistics in science, but applied in the context of paleontology."

Unless you find a dinosaur skeleton that contains the fossilized eggs that it was about to lay, or a similar dead giveaway, it's hard to be sure about an individual dinosaur's sex. But many birds, the only living dinosaurs, vary a lot between males and females on average, a phenomenon called sexual dimorphism. Dinosaurs' cousins, the crocodilians, show sexual dimorphism too. So it stands to reason that in many species of dinosaurs, males and females would differ from each other in a variety of traits.

But not all differences in animals of the same species are linked to their sex. For example, in humans, average height is related to sex, but other traits like eye color and hair color don't neatly map onto men versus women. We often don't know precisely how the traits we see in dinosaurs relate to their sex, either. Since we don't know if, say, larger dinosaurs were female, or dinosaurs with bigger crests on their heads were male, Saitta and his colleagues looked for patterns in the differences between individuals of the same species. To do that, they examined measurements from a bunch of fossils and modern species and did a lot of math.

Other paleontologists have tried to look for sexual dimorphism in dinosaurs using a form of statistics (called significance testing, for all you stats nerds) where you collect all your data points and then calculate the probability that those results could have happened by pure chance rather than an actual cause (like how doctors determine whether a new medicine is more helpful than a placebo). This kind of analysis sometimes works for big, clean datasets. But, says Saitta, "with a lot of these dinosaur tests, our data is pretty bad" -- there aren't that many fossil specimens, or they're incomplete or poorly preserved. Using significance testing in these cases, Saitta argues, results in a lot of false negatives: since the samples are small, it takes an extreme amount of variation between the sexes to trigger a positive test result. (Significance testing isn't just a consideration for paleontologists -- concerns over a "replication crisis" have plagued researchers in psychology and medicine, where certain studies are difficult to reproduce.)

Instead, Saitta and his colleagues experimented with another form of stats, called effect size statistics. Effect size statistics is better for smaller datasets because it attempts to estimate the degree of sex differences and calculate the uncertainty in that estimate. This alternative statistical method takes natural variations into account without viewing dimorphism as black-or-white-many sexual dimorphisms can be subtle. Co-author Max Stockdale of the University of Bristol wrote the code to run the statistical simulations. Saitta and his colleagues uploaded measurements of dinosaur fossils to the program, and it yielded estimates of body mass dimorphism and error bars in those estimates that would have simply been dismissed using significance testing.

"We showed that if you adopt this paradigm shift in statistics, where you attempt to estimate the magnitude of an effect and then put error bars around that, you can often produce a fairly accurate estimate of sexual variation even when the sexes of the individuals are unknown," says Saitta.

For instance, Saitta and his colleagues found that in the dinosaur Maiasaura, adult specimens vary a lot in size, and the analyses show that these are likelier to correspond to sexual variation than differences seen in other dinosaur species. But while the current data suggest that one sex was about 45% bigger than the other, they can't tell if the bigger ones are males or females.

While there's a lot of work yet to be done, Saitta says he's excited that the statistical simulations gave such consistent results despite the limits of the fossil data.

"Sexual selection is such an important driver of evolution, and to limit ourselves to ineffective statistical approaches hurts our ability to understand the paleobiology of these animals," he says. "We need to account for sexual variation in the fossil record."

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Study rules out dark matter destruction as origin of extra radiation in galaxy center

 The detection more than a decade ago by the Fermi Gamma Ray Space Telescope of an excess of high-energy radiation in the center of the Milky Way convinced some physicists that they were seeing evidence of the annihilation of dark matter particles, but a team led by researchers at the University of California, Irvine has ruled out that interpretation.

In a paper published recently in the journal Physical Review D, the UCI scientists and colleagues at Virginia Polytechnic Institute and State University and other institutions report that -- through an analysis of the Fermi data and an exhaustive series of modeling exercises -- they were able to determine that the observed gamma rays could not have been produced by what are called weakly interacting massive particles, most popularly theorized as the stuff of dark matter.

By eliminating these particles, the destruction of which could generate energies of up to 300 giga-electron volts, the paper's authors say, they have put the strongest constraints yet on dark matter properties.

"For 40 years or so, the leading candidate for dark matter among particle physicists was a thermal, weakly interacting and weak-scale particle, and this result for the first time rules out that candidate up to very high-mass particles," said co-author Kevork Abazajian, UCI professor of physics & astronomy.

"In many models, this particle ranges from 10 to 1,000 times the mass of a proton, with more massive particles being less attractive theoretically as a dark matter particle," added co-author Manoj Kaplinghat, also a UCI professor of physics & astronomy. "In this paper, we're eliminating dark matter candidates over the favored range, which is a huge improvement in the constraints we put on the possibilities that these are representative of dark matter."

Abazajian said that dark matter signals could be crowded out by other astrophysical phenomena in the Galactic Center -- such as star formation, cosmic ray deflection off molecular gas and, most notably, neutron stars and millisecond pulsars -- as sources of excess gamma rays detected by the Fermi space telescope.

"We looked at all of the different modeling that goes on in the Galactic Center, including molecular gas, stellar emissions and high-energy electrons that scatter low-energy photons," said co-author Oscar Macias, a postdoctoral scholar in physics and astronomy at the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo whose visit to UCI in 2017 initiated this project. "We took over three years to pull all of these new, better models together and examine the emissions, finding that there is little room left for dark matter."

Macias, who is also a postdoctoral researcher with the GRAPPA Centre at the University of Amsterdam, added that this result would not have been possible without data and software provided by the Fermi Large Area Telescope collaboration.

The group tested all classes of models used in the Galactic Center region for excess emission analyses, and its conclusions remained unchanged. "One would have to craft a diffuse emission model that leaves a big 'hole' in them to relax our constraints, and science doesn't work that way," Macias said.

Kaplinghat noted that physicists have predicted that radiation from dark matter annihilation would be represented in a neat spherical or elliptical shape emanating from the Galactic Center, but the gamma ray excess detected by the Fermi space telescope after its June 2008 deployment shows up as a triaxial, bar-like structure.

"If you peer at the Galactic Center, you see that the stars are distributed in a boxy way," he said. "There's a disk of stars, and right in the center, there's a bulge that's about 10 degrees on the sky, and it's actually a very specific shape -- sort of an asymmetric box -- and this shape leaves very little room for additional dark matter."

Does this research rule out the existence of dark matter in the galaxy? "No," Kaplinghat said. "Our study constrains the kind of particle that dark matter could be. The multiple lines of evidence for dark matter in the galaxy are robust and unaffected by our work."

Far from considering the team's findings to be discouraging, Abazajian said they should encourage physicists to focus on concepts other than the most popular ones.

"There are a lot of alternative dark matter candidates out there," he said. "The search is going to be more like a fishing expedition where you don't already know where the fish are."

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