Culture

Streptomyces bacteria are our primary source of antibiotics, which are produced in the transition from vegetative growth to sporulation in a complex developmental life cycle.

Previous research by Professor Mark Buttner's lab at the John Innes Centre has shown that the signalling molecule c-di-GMP binds BldD, a master repressor of gene activity, to control the initiation of development in these soil-dwelling bacteria.

c-di-GMP is an example of a nucleotide second messenger, an intracellular signal widespread in bacteria responsible for regulating crucial processes, including mobility, virulence and biofilm formation.

In a new study, experiments using the model species Streptomyces venezuelae show that c-di-GMP also intervenes later in development to control the differentiation of the reproductive hyphae into spores.

It does this by mediating an interaction between the major sporulation sigma factor in Streptomyces, WhiG, and the anti-sigma factor RsiG.

A sigma factor is a protein needed for the initiation of transcription, the process of turning DNA into RNA. Anti-sigma factors bind to the sigma and inhibit activity until the time is appropriate.

The study shows that RsiG and c-di-GMP bind and hide sigma WhiG, preventing its target genes being expressed and therefore stopping the reproductive hyphae turning into spores.

It is the first instance of c-di-GMP binding to a sigma factor and affecting its functionality.

First author of the study Dr Kelley Gallagher says: "As a result of this discovery, it is now clear that c-di-GMP signals through BldD and sigma WhiG respectively to control the two most dramatic transitions of the Streptomyces life cycle, the formation of the reproductive aerial hyphae and their differentiation into spore chains. In both cases, c-di-GMP functions as a brake."

New materials are needed to further reduce the size of electronic components and thus make devices such as laptops and smartphones faster and more efficient. Tiny nanostructures of the novel material graphene are promising in this respect. Graphene consists of a single layer of carbon atoms and, among other things, has a very high electrical conductivity. However, the extreme spatial confinement in such nanostructures influences strongly their electronic properties. A team led by Professor Michael Bonitz of the Institute for Theoretical Physics and Astrophysics (ITAP) at Kiel University has now succeeded in simulating the detailed behavior of electrons in these special nanostructures using an elaborate computational model. This knowledge is crucial for the potential use of graphene nanostructures in electronic devices.

Precise simulation of the properties of electrons in nanostructures

Last year, two research teams succeeded independently of each other in fabricating narrow, atomically precise graphene nanoribbons and measuring their electron energies. The width of the nanoribbons varies in a precisely controlled manner. Each section of the nanoribbons has its own energy states with their own electronic structure. "However, the measurement results could not be completely reproduced by previous theoretical models," says Bonitz, who heads the Chair of Statistical Physics at ITAP. Together with his Ph.D. student Jan-Philip Joost and their Danish colleague Professor Antti-Pekka Jauho from the Technical University of Denmark (DTU), they developed an improved model which led to an excellent agreement with the experiments. The physicists present their theoretical results in the current issue of the renowned journal Nano Letters.

The basis for the new and more precise computer simulations was the assumption that the deviations between the experiment and previous models were caused by the details of the mutual repulsion of the electrons. Although this Coulomb interaction also exists in metals, and indeed was included in earlier simulations in a rough way, the effect is much greater in the small graphene nanoribbons, and requires a detailed analysis. The electrons are expelled from their original energy states and have to 'search' for other places, as Bonitz explains: "We were able to prove that correlation effects due to the Coulomb interaction of the electrons have a dramatic influence on the local energy spectrum".

The shape of nanoribbons determines their electronic properties

How the permissible energy values of the electrons depend on the length, width, and shape of the nanostructures has been clarified by the team by investigating many such nanoribbons. "The energy spectrum also changes when the geometry of the nanoribbons, their width, and shape, is modified," adds Joost. "For the first time, our new data allow precise predictions to be made as to how the energy spectrum can be controlled by specifically varying the shape of the nanoribbons," says Jauho from the DTU in Copenhagen. The researchers hope that these predictions will now also be tested experimentally and lead to the development of new nanostructures. Such systems can make important contributions to the further miniaturisation of electronics.

(Boston)--Morbidity and mortality from prescription and synthetic opioid use and abuse continues to be a U.S. public health issue. In an effort to help curtail this crisis, researchers from Boston University School of Medicine (BUSM) describe an approach to ensure Physician Assistant (PA) students graduating from any PA program in Massachusetts will have the knowledge and skills to prescribe opiates safely.

"As health care educators charged with preparing the next generation of Physician Assistants, faculty in PA programs can impact this growing public health crisis of opioid misuse," explained corresponding author Susan E. White, MD, Program Director, Physician Assistant Program at BUSM. "PA faculty have the potential to improve the education of our students and hopefully have a positive impact on patient outcomes in Massachusetts and other states where our graduates will practice."

As a result, the Massachusetts Department of Public Health, along with the Massachusetts Association of Physician Assistants, created a working group for addressing the opioid crisis in the state by convening representatives from all nine PA programs to discuss curricular competencies as the Governor's Physician Assistant Education Working Group on Prescription Drug Misuse. The nine programs came together and adopted these competencies for a first-in-the-nation, cross-institutional partnership toward the prevention and management of prescription drug misuse.

In a Special Article in the Journal of Physician Assistant Education, the authors outline the consensus building techniques they used to build agreement. They also highlight the process used to bring all nine programs together and provide specific examples of how PA Programs teach students.

The authors feel the process, competencies and curricular innovations described in their article have the potential to serve as a road-map for the development of additional statewide, interdisciplinary collaborations around an educational approach to the opioid epidemic.

"It is encouraging to know that we can find common ground and, in doing so, we have the potential to improve the education of our students and hopefully have a positive impact on patient outcomes," said White, who believes the process implemented in Massachusetts could be used to address other public health crises.

"Physician assistant students need to be prepared to prevent and treat opioid use disorder and opioid overdose," said DPH Commissioner Monica Bharel, MD, MPH. "We were pleased to work with the PA schools in Massachusetts to incorporate addiction treatment into their school curricula."

Soil erosion is a global problem that threatens food security and the functioning of ecosystems. It has an adverse effect on water and air and, of course, on the soil itself. It also produces a number of harmful knock-on effects; farmers, for example, have to compensate for the loss of natural soil productivity by increasing their use of fertiliser. As things stand, soil is being lost at a significantly greater rate than it is being created. Given that the agriculture and forestry industries simply cannot function without soil, many governments are trying to combat the erosion in their countries.

Soil erosion has a whole host of causes, many of which are still not well understood. We still don't know, for example, whether and indeed how different countries influence the erosion of their soils. Research so far has focussed on identifying reciprocal relationships known as correlations, such as the fact that erosion is more severe in poor countries than in rich ones. Identifying causal effects, on the other hand, has been and remains very difficult.

Remote sensing and modelling of soil erosion

David Wuepper and Robert Finger from the Group for Agricultural Economics and Policy at ETH Zurich and Pasquale Borrelli from the University of Basel have now employed satellite imagery and numerous other data sources to investigate the socio-economic causes of soil erosion around the world.

 On the basis of high-resolution remote sensing data and numerous other data sources, the researchers created an erosion map of the world. With the help of a statistical model, the researchers then investigated whether the erosion rate is generally changing continuously through space but "jumps" abruptly at country borders. Such abrupt "jumps" at political borders  reveal the influence of the countries that are left and right of the borders.

On a second map, the researchers also modelled the potential natural erosion rate. This enabled them to see how great the difference between current and natural erosion is and whether there are natural discontinuities in the erosion rate at the political borders.

National borders reveal where erosion is unnaturally high

It was through this approach that Wuepper and Finger were able to identify the "country effect" as a cause of soil erosion. The researchers present their findings in a study recently published in the journal Nature Sustainability.

This country effect is most visible along political borders as these areas offer the best basis for comparing observations. "The rate at which soils erode strongly depends on which side of a border, and accordingly, in which country the soil lies," says lead author David Wuepper.

To illustrate their approach, the researchers use the island of Hispaniola, home to Haiti and the Dominican Republic, as an example. In its natural form, Hispaniola would be uniformly covered with dense tropical forest and natural erosion would be very low because this vegetation would protect the soil from rain.

In reality, however, the researchers found that along the border, Haiti's soils lose 50 tonnes more per year and per hectare than those of the Dominican Republic. Wuepper explains that if Hispaniola had not been subject to human intervention and were still in its natural state, there would be no sharp increase in soil erosion along the border. "But the presence of such a rise points to political entities, not natural borders," he says.

The differential erosion along the border of the two Caribbean states is extremely high: 30 times higher than the global average, which - according to the researchers' calculations - stands at 1.4 tonnes per year and hectare of arable land. By comparison, the rate of erosion in Germany is 0.2 tonnes lower than that of neighbouring countries.

The researchers consider this to be very positive because it suggests that erosion is also fairly low in the countries that border Germany. "Our findings illustrate how inconsistent the pattern observed around the world is," Wuepper says. A country's strongest influence on soil erosion is its agriculture and the way that farmers cultivate the soil there. The income level in a particular country, however, has no influence.

High potential

In addition to highlighting failures and shortcomings in soil protection, the study also shows that there is clear potential for countries to improve their soil protection and how they go about it. Finger explains that before the study, nobody realised the huge leverage that the country effect would offer. In the past, soil erosion had been seen as a predominantly local problem. "Now we've shown that larger-scale factors also strongly influence erosion in a given country," he says.

In addition, the ETH Zurich researchers' method can be used to determine whether measures that countries take to improve soil protection are effective or not. One such measure, for example, is introducing economic incentives to encourage greater soil cover or reduced tillage. However, measures to protect against erosion can also result in new conflicts of interest if, for example, reduced tillage leads to increased use of pesticides for weed control. "The basis for good policy-making in this respect is to identify and quantify these conflicting goals," Finger says.

Romantic relationships are built on trust -- yet when it comes to money, even faithful partners are not always honest about their spending and saving habits.

New research from the University of Notre Dame introduces the concept of financial infidelity -- engaging in any financial behavior likely to be frowned upon by a romantic partner and intentionally failing to disclose that behavior. The study is the first to introduce, define and measure financial infidelity reliably and succinctly and to examine its antecedents and consequences.

"Love, Lies, and Money: Financial Infidelity in Romantic Relationships" is forthcoming in the Journal of Consumer Research from coauthors Emily Garbinsky, assistant professor of marketing in Notre Dame's Mendoza College of Business, Joe Gladstone of University College London, Hristina Nikolova from Boston College and Jenny Olson of Indiana University.

"My co-authors and I became really interested in the construct of financial infidelity or cheating with money," Garbinsky explains, "because we noticed numerous popular press pieces mentioned this term and how it's much more prevalent than people think. But every article used a different definition with a different set of financial behaviors falling under this umbrella term."

The team conducted 10 lab studies using online panels of hundreds of married individuals and one field study during a Football Friday at Notre Dame (also recruiting married participants). The researchers also analyzed real bank account data collected in partnership with a couple's money-management mobile application.

They developed and validated a financial infidelity scale, or FI-Scale, to measure individual variation in consumers' proneness to financial infidelity. The scale has strong psychological measurement properties and can be used to predict actual financial infidelity among married consumers. The FI-Scale predicts a broad range of consumption-related behaviors such as spending despite anticipated spousal disapproval, preferences for discreet payment methods and nondescript packaging, and concealing bank account information.

"It's important to point out that our definition of financial infidelity is comprised of two components: engaging in a financial behavior expected to elicit disapproval, coupled with intentional failure to disclose the behavior," Garbinsky says, "including both an act and subsequent concealment, such as buying something knowing it was outside the budget and then hiding the purchase from the partner. We argue if a behavior does not reflect both components, it is not considered financial infidelity."

Consequently, FI-Scale scores predict both the likelihood of engaging in a disapproved-of financial act and the likelihood of concealing the act via a variety of marketing-relevant consumption behaviors. Consumers more prone to financial infidelity exhibit a stronger preference for secretive purchase options, ambiguous packaging and shopping at inconspicuous stores.

"As one example, I recruited married participants at Notre Dame for a football weekend," Garbinsky says, "and asked them to complete a one-page survey that contained the financial infidelity scale. At the end of the survey, they were entered into a lottery to win a free massage, and they were able to choose either a massage for themselves or a couples massage. Both options were pretested to show that, on average, most people would be upset to learn that their spouse chose an experience for themselves, when they had the option to choose something they could do together.

After making their massage choice, all participants were asked what kind of envelope they would like for their lottery ticket. Once again, they were given a choice between two things -- a white, unmarked envelope or a bright teal envelope clearly labeled as containing a lottery ticket for a massage. What the researchers found is that individuals who scored on the upper end of the FI-Scale were more likely to select a massage for themselves, making them more likely to choose the option associated with greater anticipated spousal disapproval. In addition, FI-Scale scores predicted envelope choice for those who chose the couples massage. The higher one's FI-Scale score, the more likely they were to select the unmarked envelope to help conceal their lottery ticket from their spouse.

Most people would likely admit they don't detail every financial transaction with their partner, and Garbinsky says much of that is harmless.

"If you accidentally forget to tell your partner about something you bought, then that would not be considered financially unfaithful," Garbinsky clarifies. "And there also has to be this expectation of partner disapproval. If you're, for instance, secretly saving money for a birthday gift for your partner or for a surprise trip the two of you would take together, that also would not be considered financial infidelity."

Given the key role finances play in determining relationship well-being, consumers can benefit from understanding financial infidelity and its potentially negative consequences. It can sabotage a couple's ability to accomplish financial goals like building an emergency cash fund, saving for retirement or paying off a mortgage, as well as their ability to enjoy shared experiences and relationship satisfaction.

An understanding of financial infidelity also can benefit financial services companies and advisers as well as clinical therapists and relationship counselors, all of whom play a key role in promoting consumer well-being.

Unemployment significantly increases the odds of men entering jobs traditionally performed by women. And, notably, some men find real job advantages as a result.

The U.S. labor market has been in the midst of significant changes for decades, and some traditionally male-dominated work sectors have been shrinking. Accordingly, many men in these fields risk unstable job opportunities and frequent layoffs. Not surprisingly, labor force participation rates have been declining especially among men in fields that have seen many of their jobs disappear.

On the flip side, jobs predominately filled by women have some of the highest expected job and wage growth for the future (like education and health care). While this is good news for women, these labor market shifts beg the question whether men will enter these female-dominated jobs.

Overall, men have been reticent to enter female-dominated jobs, in part, because they often pay less than comparable male-dominated jobs, and because men may face derision from friends and family for associating a central masculine marker, their job, with femininity and women.

However, an economic condition--specifically unemployment--might change that reticence and encourage men to enter a female-dominated job. And, somewhat surprisingly, unemployed men who move to female-dominated professions are finding that there are potential benefits - increased pay and occupational prestige, when compared to their previous employment.

In a study published in the journal Social Science Research, Jill Yavorsky (PhD) from the University of North Carolina at Charlotte and Janette Dill (PhD) from the University of Minnesota find that men who previously worked in male-dominated or mixed-gender fields are significantly more likely to transition to female-dominated jobs following a bout of unemployment.

When they do, their wages increase, on average, by four percent from their previous employment and their occupational prestige also increases. Men who eventually find new employment in male-dominated or mixed-gender fields either maintain past levels or lose ground in these areas, the analysis indicates.

The research finding is based on analyses from the Survey of Income and Program Participation, surveys administered by the U.S. Census Bureau.

Yavorsky notes that, before studying the data, the researchers came into the study with two competing hypotheses: First, unemployed men faced with the stigma that often comes with job loss might "hunker down" and be less willing to accept a further hit to their masculinity that might come from doing a job traditionally seen as "women's work." The alternative hypothesis was that the practical stresses of unemployment and lack of income would provide enough stimulus to encourage men to think about previously ignored career choices.

The data clearly showed that the second expectation was true.

"What our study suggests is that unemployment may act as a shock that encourages men to consider job alternatives that they might not otherwise consider while employed," Yavorsky said. "When men are facing potentially missed housing, car payments, or the lack of an income stream, that's really meaningful."

This school-of-hard-knocks effect seemingly results in an important social adaptation.

"This is particularly important, given shifting labor market conditions. Over the past several decades, male-dominated jobs - and really working-class male-dominated jobs - have been disappearing. We know that the labor market is moving toward many female-dominated jobs, such as those in healthcare and education," Yavorsky noted.

"Research by economists and sociologists has pointed to the fact that if some men do not start to re-shift their job choices, they are at risk of being left behind, or facing persistent job instability due to frequent layoffs," Dill said.

What is further good news in the study for men, and even more unexpected, are the findings that men's wages and occupational prestige may increase in making the transition after unemployment -- over what they were prior to unemployment. Wages, the study found, increase for men entering female-dominated fields by an average four percent and the prestige of their occupation increases significantly as well, on the basis of the Nakao-Treas prestige score, a standard occupational measure in sociology.

"These potential wage and prestige benefits are meaningful because they suggest that taking a female-dominated job may help some men to avoid the common scarring effects of unemployment," Yavorsky said.

"A host of social science research has shown that workers often take a hit to their wages and job status in the position they take after unemployment. Thus, it is significant that in some cases going into a female-dominated job may help offset typical costs associated with unemployment," she notes.

According to Yavorsky and Dill, there are a variety of possible explanations for why the change to female-dominated work means potential higher wages and increases in occupational prestige for men. During unemployment, men's searches for female-dominated jobs may be targeted toward upgraded jobs, in order to offset any stigma they may face for entering jobs traditionally thought of as "women's work." Additionally, men's previous experience in male-dominated or mixed-gender jobs may be more highly valued by employers, giving them a leg-up and allowing them to enter better jobs.

Yavorsky and Dill note that it is important to contextualize the increases in occupational prestige that some men experienced by entering female-dominated fields. Yavorsky states, "Many men transitioned from manual working-class jobs to entry-level white-collar female-dominated jobs. This is important because these white-collar jobs might offer greater long-term job security, given the precarity of many male-dominated working-class jobs."

Moreover, the authors point out that entrance into white-collar female-dominated jobs may be a springboard for future upward advancement.

"There is an interesting concept called 'the glass escalator' that has been pretty well studied over the last 25 years or so," Yavorsky said. "The glass escalator describes the advantages men often experience in female-dominated jobs. Specifically, men -- particularly white men -- tend to have higher wages and be promoted more quickly than their women peers."

"Of course, we do not see the reverse situation for women who go into male-dominated jobs," she noted. "In fact, research clearly documents that women continue to face a host of disadvantages, including lower wages and difficulties in getting promoted."

Overall, given that men have not made much progress entering female-dominated jobs over the past several decades, this study shows that individual economic conditions really matter for men's job decisions.

"Our study highlights the fact that men open up their job options to include female-dominated fields when faced with unemployment. Not only that, but there may be benefits associated with going into these jobs--benefits that could have real implications for men and their families given the financial constraints typically associated with unemployment," Yavorsky concluded.

At the same time, she cautions drawing too large of implications from the study.

"A key limitation is that the data used only allows us to look at short-term events. We don't know how men's careers continue in female-dominated jobs, how long they stay in these jobs, or how their wage trajectory goes."

Patients with active cannabis dependence and abuse were nearly twice as likely to suffer a heart attack after surgery, according to a study led by researchers at St. Michael's Hospital of Unity Health Toronto.

The study, published in the Online First edition of Anesthesiology, the peer-reviewed medical journal of the American Society of Anesthesiologists (ASA), also found the prevalence of cannabis dependence or abuse recorded among surgical patients increased significantly over the last decade.

Researchers analyzed the records of over 4 million adults in the United States from 2006 to 2015 undergoing one of 11 common elective procedures including knee or hip replacement, gallbladder removal, caesarian section, hysterectomy, and hernia repair.

"While cannabis is often purported as being safe or benign, we don't fully understand the health implications of this drug, particularly in heavy users," said Dr. Karim Ladha, a clinician-scientist at the Li Ka Shing Knowledge Institute of St. Michael's Hospital and lead author of the study.

"The results of this study make it clear that we need to pay more attention to cannabis users undergoing surgery," said Dr. Ladha.

Dr. Ladha noted that this research was the first step in determining whether there is any association between cannabis use disorders and perioperative outcomes. Dr. Ladha's subsequent work will prospectively follow patients with self-reported cannabis use disorder undergoing surgery using a more detailed method of data collection to determine if the association persists.

The findings did not show a difference in overall outcomes between patients who had a cannabis use disorder and those who did not. However, in addition to increased cardiac risk, there was evidence that patients with cannabis use disorders were possibly at an increased risk for a stroke.

Type 2 diabetics inject themselves with insulin, a hormone that regulates the movement of sugar into liver, muscle and fat cells, up to four times a day. But insulin injections are linked to weight gain and the loss of control of blood sugar levels. This triggers a vicious cycle of higher insulin doses, continuous weight gain, a higher incidence of cardiovascular disease and other complications.

A new Tel Aviv University study finds that a starch-rich breakfast consumed early in the morning coupled with a small dinner could replace insulin injections and other diabetes medications for many diabetics.

"The traditional diabetic diet specifies six small meals spread throughout the day. But our research proposes shifting the starch-rich calories to the early hours of the day. This produces a glucose balance and improved glycemic control among type 2 diabetics," explains Prof. Daniela Jakubowicz of TAU's Sackler Faculty of Medicine and Wolfson Medical Center's Diabetes Unit. "We believe that through this regimen it will be possible for diabetics to significantly reduce or even stop the injections of insulin, and most of antidiabetic medications, to achieve excellent control of glucose levels."

Prof. Jakubowicz is the lead author of the study, the result of a collaboration with Prof. Julio Wainstein and Dr. Zohar Landau of Wolfson Medical Center's Diabetes Unit and Prof. Oren Froy and Dr. Shani Tsameret of the Hebrew University of Jerusalem. The research was published in Diabetes Care in December.

According to the new research, our metabolism and biological clock are optimized for eating in the morning and for fasting during the evening and night, when we are supposed to be asleep. "But the usual diet recommended for type 2 diabetes consists of several small meals evenly distributed throughout the day -- for example, three meals and three snacks daily, including a snack before going to sleep to prevent a drop in sugar levels during the night," Prof. Jakubowicz says.

"But the '6M-diet,' as this is called, has not been effective for sugar control, so diabetics require additional medication and insulin. And insulin injections lead to weight gain, which further increases blood sugar levels," Prof. Jakubowicz adds.

The researchers studied 29 type 2 diabetes participants and compared a new "3M-diet," more in alignment with our biological clock, with a control group on the traditional 6M-diet. The experimental 3M-diet comprises a meal of bread, fruits and sweets in the early hours of the morning; a substantial lunch; and a small dinner specifically lacking starches, sweets and fruits.

The group on the traditional 6M-diet did not lose weight and did not experience any improvement of sugar levels, requiring an increase in medication and insulin doses. But the group on the 3M-diet not only lost weight but also experienced substantially improved sugar levels.

"Their need for diabetic medication, especially for insulin doses, dipped substantially. Some were even able to stop using insulin altogether," adds Prof. Jakubowicz. "In addition, the 3M-diet improved the expression of biological clock genes. This suggests that the 3M-diet is not only more effective in controlling diabetes. It may also prevent many other complications such as cardiovascular disease, aging and cancer, which are all regulated by the biological clock genes."

The upregulation of the biological clock gene expression in the 3M-diet might be the mechanism behind its success, as it enhances insulin secretion and improves sugar delivery into the muscles, creating a balanced daytime and nocturnal glucose metabolism. The researchers are now investigating the role certain proteins play in breakfast foods consumed by diabetics.

A new study into the recent history of the Great Barrier Reef has shown how it responds to rapid sea-level rise and other environmental stresses. The study, conducted at the University of Sydney's research station at One Tree Island, has upended the established model of Holocene-era reef growth.

Using unprecedented analysis of 12 new drilled reef cores with data going back more than 8000 years, the study shows that there have been three distinct phases of reef growth since the end of the Pleistocene era about 11,000 years ago.

"We wanted to understand past reef resilience to multiple environmental stresses during the formation of the modern reef," said lead author Kelsey Sanborn, a PhD student in the School of Geosciences at the University of Sydney.

The study, published in Sedimentary Geology, revealed a period between 8000 and 7000 years ago when the reef growth slowed as it was exposed to multiple stresses, including likely increases in sediment and nutrient flux on the reef.

As the ice caps and glaciers melted at the beginning of the Holocene era, sea level rapidly rose by up to seven metres every thousand years, flooding the continental shelf until about 7000 years ago. At the same time, it is estimated sea-surface temperatures likely increased several degrees between 8000 and 6000 years ago.

"We are fortunate that the sea level stabilised about 6000 to 7000 years ago. If it had continued to rise as fast as it had been, the reef might not have survived given its slow growth rate," Ms Sanborn said.

Associate Professor Jody Webster, a co-author of the paper and Ms Sanborn's supervisor, said that there are multiple environmental drivers affecting both the historic and modern reef system.

"We need to understand the past in order to predict the future. This paper and Kelsey's broader research examine how sea level, surface temperature, sediment in the water, nutrient influx and energy inputs into the reef system affect its vulnerability to environmental change," he said.

"The reef system survives because of a delicate balance these environmental factors. Anthropogenic climate change is threatening to interfere with this balance."

Three phases of growth

1. Clear water, fast growth

Between 1000 and 700 years after the continental shelf was flooded, corals started to grow, rebuilding the reef after a 100,000-year hiatus. Up to about 8000 years ago, the first corals to grow around One Tree Island were mostly shallow, clear-water and fast-growing, with a vertical reef growth of about 6 millimetres a year.

2. Slower, deeper growth

Between 8000 and 7000 years ago, reef growth slowed as waters continued to rise quickly. Temperatures rose and the quality of the water also changed in this period with an increase in sediment and nutrients. The types of corals were massive in form, sediment-tolerant and growth was deeper, at times up to 5 metres below sea level.

3. Catch-up growth

A slow-down and stabilisation of sea-level rise led to a fast (5 millimetres a year) vertical growth until the reef caught up to current sea levels about 6000 years ago. Growth in this period was mostly composed of shallow, branching coral assemblages.

New model of reef growth

A surprising result of the research is evidence that initial reef growth occurred on the low-energy, leeward side of the reef, ahead of growth on the high-energy, windward side.

"This is contrary to established models of reef growth," Ms Sanborn said. "In those models, the part of the reef exposed to higher energy inputs from waves and wind were thought to have been cleared of land-based ecosystems, clearing the way for reef development."

The paper proposes a new model that needs further testing in other regions of the Great Barrier Reef and reef systems around the world. What it establishes is that the more protected parts of the reef might have been more suitable for early coral development.

"This provides new constraints on how we understand changes in the environment controlling reef development through sea-level rise and inundation," Ms Sanborn said.

Scientists studying the weather and climate of Titan, Saturn's largest moon, have reported a significant seasonal variation in its energy budget - that is the amount of solar energy absorbed by the celestial body and the thermal energy it emits.

The findings, reported in the journal Geophysical Research Letters, could lead to new insights about climate on Earth.

Titan is the only body in the solar system, other than Earth, with a significant atmosphere and liquid surface lakes. "By studying Titan, we can learn a lot about Earth," said Ellen C. Creecy, a doctoral student in the Department of Earth and Atmospheric Sciences at the University of Houston and first author of the paper.

There are significant differences between the two, as well, she said. The surface liquid on Titan is liquid methane, rather than water, for example. And it takes Saturn and its moons far longer to complete an orbit around the sun.

Liming Li, a physics professor at UH and corresponding author on the paper, said it takes Saturn about 29 Earth years to complete its orbit. Still, he said, learning more about the energy budget of Titan can add to understanding of climate change on Earth.

Previous studies have detected a small energy imbalance on Earth, he said. "Earth's small energy imbalance has significant effects on its global warming and climate change," he said. "We expect that the dynamically-varying energy budget and the possible energy imbalance have important impacts on the weather and climate systems on Titan."

The researchers used data collected from the Cassini mission between 2004 and 2017 - the equivalent of about half an Earth year for Saturn and Titan, or portions of three seasons. That data provided the first opportunity to systematically examine the seasonal variations of Titan.

While previous studies have suggested Titan's energy budget is in balance, the researchers determined that both emitted thermal energy and absorbed solar energy decreased over the 14-year period studied. But thermal emissions dropped less - about 6.8%, compared with an 18.6% drop in solar energy at Titan. That varied between the northern and southern atmospheres of Titan, as well as depending on the moon's distance from the sun during its orbit.

The findings suggest the distance between the sun and Earth may play a role in Earth's energy balance, said Xun Jiang, professor of atmospheric science at UH. She and Li serve as co-doctoral advisors for Creecy, whose future research will be supported by a new $433,210 grant (10/1/2020-9/30/2023) from NASA. Li is principal investigator on that grant.

"Such a mechanism has not been examined for Earth's energy imbalance," Jiang said, noting that future work will compare Titan and Earth's energy budgets in order to better understand the climate systems on each.

In addition to Creecy, Li and Jiang, researchers on the project are C.A. Nixon of the NASA Goddard Space Flight Center and R.A. West and M.E. Kenyon of the Jet Propulsion Laboratory at the California Institute of Technology.

Creecy said additional work will be needed to better understand what the observed energy imbalance means for Titan.

"The possible energy imbalance means that Titan's atmospheric system keeps evolving," she said. "There are complicated interaction between the energy budget and atmospheric system, which is being explored by our research."

Pasadena, CA-- A surprising analysis of the composition of gas giant exoplanets and their host stars shows that there isn't a strong correlation between their compositions when it comes to elements heavier than hydrogen and helium, according to new work led by Carnegie's Johanna Teske and published in the Astronomical Journal. This finding has important implications for our understanding of the planetary formation process.

In their youths, stars are surrounded by a rotating disk of gas and dust from which planets are born. Astronomers have long wondered how much a star's makeup determines the raw material from which planets are constructed--a question that is easier to probe now that we know the galaxy is teeming with exoplanets.

"Understanding the relationship between the chemical composition of a star and its planets could help shed light on the planetary formation process," Teske explained.

For example, previous research indicated that the occurrence of gas giant planets increases around stars with a higher concentration of heavy elements, those elements other than hydrogen and helium. This is thought to provide evidence for one of the primary competing theories for how planets form, which proposes that gas giant planets are built from the slow accretion of disk material until a core about 10 times Earth's mass is formed. At this point, the solid baby planetary interior is able to surround itself with helium and hydrogen gas, birthing a mature giant planet.

"Previous work looked at the relationship between the presence of planets and how much iron exists in the host star, but we wanted to expand that to include the heavy element content of the planets themselves, and to look at more than just iron," explained co-author Daniel Thorngren, who completed much of the work as a graduate student at UC Santa Cruz and is now at the Université de Montréal.

Teske, Thorngren and their colleagues--Jonathan Fortney of UC Santa Cruz, Natalie Hinkel of the Southwest Research Institute, and John Brewer of San Francisco State University--compared the bulk heavy element content of 24 cool, gas giant planets to the abundances of "planet-forming elements" carbon, oxygen, magnesium, silicon, iron, and nickel in their 19 host stars. (Some stars host multiple planets.)

They were surprised to find that there was no correlation between the amount of heavy elements in these giant planets and the amount of these planet-forming elements in their host stars So how can astronomers explain the established trend that stars rich in heavy elements are more likely to host gas giant planets?

"Unraveling this discrepancy could reveal new details about the planet formation process," explained Fortney. "For example, what other factors are contributing to a baby planet's composition as it forms? Perhaps its location in the disk and how far it is from any neighbors. More work is necessary to answer these crucial questions."

One clue may come from the authors' combined results bundling the heavy elements into groupings that reflect their characteristics. The authors saw a tentative correlation between a planet's heavy elements and its host star's relative abundance of carbon and oxygen, which are called volatile elements, versus the rest of the elements included in this study, which fall into the group called refractory elements. These terms refer to the elements' low boiling points--volatility--or their high melting points--in the case of the refractory elements. Volatile elements may represent an ice-rich planetary composition, whereas refractory elements may indicate a rocky composition.

Teske said: "I'm excited to explore this tentative result further, and hopefully add more information to our understanding of the relationships between star and planetary compositions from upcoming missions like NASA's James Webb Space Telescope, which will be able to measure elements in exoplanet atmospheres."

The levels of PCBs in the air are high enough to affect thyroid hormones in people who reside close to the harbor, raising the risk of diabetes, low birth weight, and impaired neurodevelopment.

A new Boston University School of Public Health (BUSPH) study indicates that the contaminated water of New Bedford Harbor may pose an airborne health hazard for residents living nearby in Acushnet, Dartmouth, Fairhaven, and New Bedford. The U.S. Environmental Protection Agency (EPA) declared the southeastern Massachusetts harbor a Superfund site and has been cleaning up sediment contaminated with polychlorinated biphenyls (PCBs) since the 1990s, focusing efforts on PCB levels in the sediment and in fish consumed from the harbor, and associated cancer risks.

But the new study, published in Science of the Total Environment, is the first to estimate the non-cancer health effects of breathing airborne PCBs around the harbor, namely thyroid hormone effects.

"Residents have been concerned about the air for over a decade. Our study shows that they are correct to be concerned," says Dr. Wendy Heiger-Bernays, the study's corresponding author and a clinical professor of environmental health at BUSPH. "It also indicates that it's important to monitor the PCBs in air as a measure of a successful cleanup."

By request from community members, the researchers previously measured airborne PCB levels in various locations around the harbor in 2015 and 2016, including during a period of hydraulic dredging as part of the site's cleanup. For the new study, the researchers estimated the health effects of these measurements. The EPA has no published guidelines for the amount of PCBs in air that might be safe to breathe, so the BUSPH team used evidence from other researchers' rodent studies to develop a human-equivalent estimate of the likelihood of different levels of airborne PCB exposure to cause "unreasonable risk" as the EPA defines it. They found that the airborne PCB levels were high enough to potentially affect the thyroid hormones of residents, particularly those living within 625 meters (0.4 miles) of the harbor.

"In addition to cancers, residents have been very concerned about other health problems that are not typically considered by health agencies when regulating exposures," says Dr. Madeleine Scammell, associate professor of environmental health at BUSPH and co-lead of the study. "Although clean-up of the harbor is nearly complete, and some may feel this is 'too little too late,' we hope our results can inform other settings where inhaled PCBs are a risk, so that subtler human health risks are factored into the equation."

Young children whose household received a housing voucher were admitted to the hospital fewer times and incurred lower hospital costs in the subsequent two decades than children whose households did not receive housing vouchers, according to a new study from researchers at Johns Hopkins Bloomberg School of Public Health.

The study was published online December 3 in JAMA.

The findings, which tracked hospitalizations over time after households participated in a voucher program, are potentially relevant for the approximately four million children living in low-income households receiving Housing and Urban Development assistance, the researchers say.

The study found that children age 12 or under whose household received a housing voucher had 27 percent lower spending on hospitalizations--nearly $200 per year--than children whose household did not receive a housing voucher. Children 12 or younger whose family received a housing voucher were hospitalized 18 percent less than children whose family did not during the follow-up period. Moving to a lower-poverty neighborhood was linked with lower health care spending and fewer hospital admissions for younger children. The study did not find comparable savings or fewer hospitalizations in older children or in adults whose households received housing vouchers to move to lower-poverty neighborhoods.

The study used data collected by the U.S. Department of Housing and Urban Development in an experimental program--the Moving To Opportunity for Fair Housing Demonstration Project--that gave low-income families living in public housing the chance to move with a housing voucher. Researchers linked households with insurance and hospital data representing 11 years to 21 years after enrollment in the program.

"While the long-term financial benefits of helping young children move out of high-poverty neighborhoods has increasingly been recognized, these findings underscore the potentially significant health impacts," says lead author Craig Evan Pollack, MD, associate professor in the Bloomberg School's Department of Health Policy and Management. "The fact that we see lower hospital spending over such a long follow-up period suggests the enduring importance of helping young children live in opportunity neighborhoods."

The Moving to Opportunity for Fair Housing Demonstration Project enrolled 4,604 families living in public housing developments or in high-poverty neighborhoods in Baltimore, Boston, Chicago, Los Angeles, and New York from 1994 to 1998. Families were randomly selected to 1) receive a housing voucher that needed to be used in a low-poverty neighborhood, 2) receive a housing voucher without neighborhood restrictions, or 3) were assigned to a control group.

The study sample focused on 4,072 adults and 9,118 children ages 18 years or younger at the time of receiving the housing voucher. Children under 18 were then divided by age, 13 years and older and 12 and under, and by gender. Households were followed up to 21 years after enrolling in the Moving to Opportunity for Fair Housing Demonstration Project.

Researchers linked participants to hospital discharge and Medicaid data to evaluate the association of housing vouchers with hospital utilization and spending among children and adults from 1995 to 2015, depending on city and health records. The study focused on the number of annual hospitalizations, the number of inpatient hospital days per year, and total annual hospital spending for adults, children under 18, and children under 13.

Researchers found that children under 18 whose family received a housing voucher had an 18 percent reduction in annual hospital spending compared to children who did not receive a housing voucher ($633 dollars compared to $785). They also found that there was a 15 percent lower rate of hospitalizations for children under 18 who received a housing voucher. For every 10 percentage point reduction in neighborhood poverty--e.g., moving from a neighborhood where 40 percent of the households lived below the poverty line to one with 30 percent below the poverty line--households, on average, spent $152 less per year in the hospital on children under 18.

There were no significant associations with rates of hospitalizations, number of hospital days, or annual spending in adults.

On average, adults were 32 years old at the time they received a housing voucher. Sixty-four percent were black, and 32 percent were Hispanic. About a quarter of the adult study sample were employed and about a third (37 percent) had a high school diploma. Children were 8 years old on average at the time the household received a housing voucher. Sixty-five percent identified as black and approximately 31 percent were Hispanic.

"Reducing the level of poverty that children are exposed to in the neighborhoods where they grow up may be one way to lower health care costs," explains Pollack. "Housing policies should take into account the potential implications for health care use over the long run."

All neurodegenerative diseases have a common thread: the appearance of protein clumps in the brain such as amyloid-beta plaques in Alzheimer's disease and alpha synuclein aggregates in Parkinson's. The root cause of this buildup has been hard to pinpoint, but Rockefeller scientists have identified a likely culprit that opens up a new avenue for developing treatments.

In a pair of studies carried out in flies and mice, the researchers discovered that the issue lies in the system that transports proteasomes, the molecular machinery that breaks down proteins, to specific locations within a cell.

"This is the first study to find a mechanism by which the proteasomes are moved to nerve endings to do their job," says Hermann Steller, the Strang Professor at Rockefeller. "When this mechanism gets disrupted, there are severe consequences for the function and long-term survival of nerve cells."

Location, location, location

Proteasomes are made in the cell body of a neuron and need to be transported over long distances to reach the nerve endings where the neuron connects with other cells--a journey of more than one meter in some cases. When proteasomes fail to reach these critical communication hubs, the cell descends into turmoil.

"Instead of being degraded, damaged proteins in these sites hang around long enough to interact with other binding partners, form aggregates, and disrupt cell function," Steller says. Over time, this causes degeneration of nerve fibers and ultimately cell death.

When Steller and his team began investigating the proteasome transportation system in fruit flies, they identified a protein called PI31, which plays a crucial role in loading the proteasomes onto the cellular components that ferry them around. In research published in Developmental Cell, they show that PI31 enhances binding and promotes movement of proteasomes with cellular motors. Without it, transport is halted. This is the case in both fly and mouse neurons, suggesting that the transport mechanism is common between many species.

Digging deeper into what happens when PI31 is defective, the scientists worked with Mary Beth Hatten's lab to generate mice whose PI31 gene was switched off in two groups of brain cells with particularly long extensions. In research published in the Proceedings of the National Academy of Sciences, they found that without PI31, proteasomes cannot travel, resulting in abnormal proteins levels at the tips of neuronal branches. The PI31-lacking neurons also looked peculiar, both with respect to their branches and to their synapses, the structures where branches from two neurons connect.

"Notably, these structural changes became progressively more severe with age," says Steller. "Inactivation of PI31 in these neurons was reminiscent of the severe behavioral and anatomical defects we see in some human neurogenerative disease."

Opportunities for therapy

There are other reasons to suspect that the lab's findings could inform the treatment of neurodegenerative diseases. For example, mutations in a human gene called PARK15, which is critical for PI31 activity, have been identified in a severe form of early-onset Parkinson's disease; and mutations in the PI31 gene itself have been linked to Alzheimer's disease.

Steller and his team are now working to determine if PI31, or molecules that affect its activity, are viable drug targets. The fact that PI31 appears to be involved in the early stages of nerve cell degeneration is especially compelling, as it could mean that drugs blocking this protein might have the potential to halt brain damage early on in the process.

As for what actually causes brains to degenerate, Steller believes the formation of aggregates is likely not the direct disease mechanism, but rather a symptom of bigger problems. "Our work suggests that it really starts with a local defect in proteasomes, resulting in the failure to degrade proteins that are critical for nerve function" he says. "These undigested proteins subsequently form aggregates and activate additional damage control pathways.  But eventually, these clearance systems are overwhelmed, which causes a slow but steady progression to a detectable disease."

Steller and his colleagues are now investigating ways to stimulate the transportation pathway to get proteasomes out to the distal branches--work they believe could have a broad impact on the treatment of neurodegenerative diseases.

In a paper published in the Journal of Biological Chemistry, University of Illinois at Chicago researchers and colleagues report a new mechanism for detecting foreign material during early immune responses.

Viruses, bacteria and cancer have many ways to replicate and survive in our bodies. For viruses and bacteria, they invade a cell directly to avoid detection. Cancer cells have the advantage of being native in the body. However, the body has safeguards against such sneaky tactics.

"There are proteins in the cell that await the presence of foreign material," said Marlene Bouvier, senior author and UIC professor of microbiology and immunology at the College of Medicine. "One protein, called endoplasmic reticulum aminopeptidase 1, or ERAP1, is programmed to find foreign material, like viral and bacterial proteins, and break it into smaller parts, also known as peptides. Another protein -- major histocompatibility complex class I, or MHC I -- is programmed to attach itself to a foreign peptide and move it to the cell's surface. With the foreign peptide outside the cell, immune cells can recognize and destroy the infected cell."

This is an example of a normal process, Bouvier said, but sometimes a foreign peptide, once bound to MHC I, remains in the cell. This happens when the foreign material is not broken down to a small enough size or is too long.

Bouvier and colleagues used X-ray crystallography -- a method to see structures on an atomic level -- and mass spectrometry -- used to identify peptide length by mass -- to show that ERAP1 can cut extra-long peptides even after they have bound to MHC I.

"X-ray crystallography allowed us to determine three-dimensional structures to see how these longer peptides bound to the MHC I groove with high resolution," Bouvier said. "Using an ERAP1 enzymatic assay with mass spectrometry gave us the ability to show, for the first time, that ERAP1 can trim peptides bound to MHC I. These tools allowed us to develop a model of this new immune response mechanism."

Bouvier said this new information may help researchers leverage ERAP1 to fight infections and cancer.

"This research can have major implications for immunotherapies," said Bouvier. "For example, cancer cells do not always present enough peptides to be labeled as 'foreign' -- allowing the cancer cells to replicate and grow. But if you have a way to manipulate how ERAP1 generates cancer peptides, then you can hopefully skew the peptide repertoire that is presented on the cell surface in our favor. This is the most translational application of our research."

This study was selected as the journal's "Editors' Pick" for the significance and importance of their research to the immunology field.