The effects of repeated droughts on different kinds of forests — ScienceDaily

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Drought is endemic to the American West along with heatwaves and intense wildfires. But scientists are only beginning to understand how the effects of multiple droughts can compound to affect forests differently than a single drought alone.

UC Santa Barbara forest ecologist Anna Trugman — along with her colleagues at the University of Utah, Stanford University and the U.S. Forest Service — investigated the effects of repeated, extreme droughts on various types of forests across the globe. They found that a variety of factors can increase and decrease a forest’s resilience to subsequent droughts. However, the study, published in Nature Climate Change, concluded that successive droughts are generally increasingly detrimental to forests, even when each drought was no more extreme than the initial one.

Droughts usually leave individual trees more vulnerable to subsequent droughts. “Compounding extreme events can be really stressful on forests and trees,” said Trugman, an assistant professor in the Department of Geography. She compares the experience to a person battling an illness: You’ll be harder hit if you get sick again while you’re still recovering.

That said, the case is not quite so clear cut. “Theoretically, responses to subsequent droughts could be quite varied depending on a wide range of tree-level and ecosystem-level factors,” said lead author William Anderegg, an assistant professor at the University of Utah. So, while a drought may place a tree under considerable stress, it could also kill off some of its neighbors, leaving the survivors with less competition for water should arid conditions return.

Trugman and her colleagues used a variety of data sources to investigate this effect on a broad scale. Tree ring data spanning over 100 years enabled them to see how trees that survived an initial drought grew afterward. Data from the U.S. Forest Inventory and Analysis gave

Effects of poverty on childhood development seen in children as young as 5 — ScienceDaily

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In a nationwide study, UCLA researchers have found that health inequities can be measured in children as young as 5 years old. The research, published in Health Affairs, contributes to a growing body of literature finding that children of color who are also poor face greater health inequities than their white counterparts.

Researchers trained kindergarten teachers in 98 school districts across the United States to administer the Early Development Instrument (EDI), a measure of children’s physical, social, emotional and language development.

The assessment was administered to more than 185,000 kindergarteners from 2010 to 2017. After analyzing and correlating the results according to where the children lived, the investigators found that 30 percent of children in the lowest-income neighborhoods were vulnerable in one or more domains of health development, compared to 17 percent of children in higher-income settings.

The researchers also found that income-related differences in developmental vulnerability varied substantially among children from different ethnic and racial groups. Black children, for example, were at highest risk, followed by Latina/o children. Asian children were at lowest risk. The differences in developmental vulnerability between Black children and white children were most pronounced at the higher socioeconomic levels and tended to narrow for Black and white children from lower-income neighborhoods. Such early disparities can have a profound influence on children’s long-term development, leading to higher rates of chronic conditions such as diabetes, heart disease, drug use, mental health disorders and dementia as adults.

“Our findings underscore the pronounced racialized disparities for young children,” says lead study author Neal Halfon, MD, director of the Center for Healthier Children, Families and Communities at UCLA. “Many other studies have highlighted patterns of income and racial inequality in health and educational outcomes. What this study shows is that these patterns of inequality are clearly evident and measurable

Has COVID-19 knocked us onto our backsides? Researchers study pandemic’s effects on physical activity and sedentary behavior — ScienceDaily

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Because of the COVID-19 pandemic, most universities across the United States transitioned from face-to-face classes to remote learning, closed campuses and sent students home this past spring. Such changes, coupled with social distancing guidelines, have altered social interactions and limited our access to fitness facilities, parks and gymnasiums. This is concerning as positive social interaction and access to exercise facilities both promote physical activity. Recently, a group of Kent State University researchers sought to examine the impact of these pandemic-related changes upon physical activity and sedentary behavior, specifically sitting, across the university population.

Kent State’s College of Education, Health and Human Services professors Jacob Barkley, Ph.D., Andrew Lepp, Ph.D., and Ellen Glickman, Ph.D., along with current and former Kent State doctoral students Greg Farnell, Ph.D., Jake Beiting, Ryan Wiet and Bryan Dowdell, Ph.D., assessed the impact of the COVID-19 pandemic on physical activity and sedentary behavior. More than 400 college students, faculty, staff and administrators reported their typical physical activity and sedentary behavior before the COVID-19 pandemic and after the transition to remote learning and the closure of campus.

In this before-and-after comparison, participants reported nearly eight hours more sitting per week after transitioning from face-to-face classes to remote learning. Changes in physical activity were not so straightforward. Those participants who were not highly active before the pandemic actually increased physical activity after the closure of campus and the transition to remote learning, while participants who were highly active before the pandemic experienced a decrease in overall physical during the pandemic.

“It appears that the participants who were most physically active before the pandemic may have been the most negatively affected,” Barkley said. “This makes sense as these active individuals are more likely to utilize the fitness facilities that were closed when the pandemic hit. However, the increases in physical

Ocean warming and acidification effects on calcareous phytoplankton communities

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IMAGE

IMAGE: Examples of normally formed (a, c) and malformed (b, d) specimens of E. huxleyi (above) and R. clavigera (below) observed in the mesocosm samples
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Credit: ICTA-UAB

A new study led by researchers from the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) warns that the negative effects of rapid ocean warming on planktonic communities will be exacerbated by ocean acidification.

The research, recently published in the journal Scientific Reports of Nature, shows that some of the major environmental changes projected for this century in the Mediterranean Sea (e.g., ocean acidification, ocean warming, and the increasingly frequent marine heatwaves in summer) can have adverse effects on the productivity of calcifying phytoplankton communities (coccolithophores).

Carbon dioxide (CO2) emissions by human activities have alarmingly increased in the past decades. A quarter of this anthropogenic CO2 has been absorbed by the ocean, changing the chemistry and ultimately lowering the pH of the seawater, a phenomenon known as ocean acidification.

The extra heat trapped in the atmosphere due to greenhouse gases is also causing the warming of the seawater (which annually absorbs up to 90% of this heat). The process hampers the supply of nutrients to the upper ocean layers, due to a sharp stratification of the surface water column.

“Atmospheric warming is expected to evolve in the Mediterranean area 20% faster than the global average, and marine heatwaves will occur with increasing frequency by the end of the 21st century, with serious consequences for marine biodiversity and production”, says Dr Patrizia Ziveri, ICREA Research Professor at the ICTA-UAB.

Coccolithophores, a very abundant group of marine calcifying phytoplankton, play a major role in the biogeochemical cycles and in the regulation of the global climate. These tiny algae, which measure 2 through

Mosquitos lost an essential gene with no ill effects

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Mosquitos lost an essential gene with no ill effects
The exoskeletons of a normal mosquito larva on the left and a mosquito larva with the gooseberry gene edited out on the right. Credit: Alys Jarvela/University of Maryland.

University of Maryland entomologists discovered that a gene critical for survival in other insects is missing in mosquitos—the gene responsible for properly arranging the insects’ segmented bodies. The researchers also found that a related gene evolved to take over the missing gene’s job. Although laboratory studies have shown that similar genes can be engineered to substitute for one another, this is the first time that scientists identified a gene that naturally evolved to perform the same critical function as a related gene long after the two genes diverged down different evolutionary paths.


The work emphasizes the importance of caution in genetic studies that use model animals to make conclusions across different species. It also points to a new potential avenue for research into highly targeted mosquito control strategies. The research study was published in the September 30, 2020, issue of the journal Communications Biology.

“Every single arthropod has a segmented body plan. And you would think it develops the same way in all of them. But what we found is that it doesn’t,” said Alys Jarvela, a postdoctoral associate in the UMD Department of Entomology and the lead author of the study. “We learn a lot in biology by studying a process in a model organism and assuming that it works essentially the same way, using the same genes, in other organisms. That is still an incredibly useful approach. But, now we know that there is also a possibility for gene substitutions to be made in nature.”

Jarvela discovered the missing gene in mosquitos by accident. She was studying crickets and attempting to cross-check her genetic samples by comparing the gene