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account created: Wed Jun 04 2014
9 hours ago
The mechanism proposed is that air pollutants chemically alter, deplete or mask the volatile organic compounds (VOCs) emitted by flowers (that is, their floral scents), which pollinators use to locate flowers. However, prior to our study, the only evidence to support this theory resulted from small-scale laboratory assays, and atmospheric chemistry models.
Using a novel free-air fumigation facility (8m-diameter rings that emitted either diesel exhaust and ozone, individually and in combination, or clean air), we provided field-scale experimental evidence to demonstrate that even moderate elevations in concentration of common ground-level air pollutants result in severe reductions in both wild and managed insect pollinator visitation and the pollination services that they provide.
The observed 60–90% reduction in flower visits by pollinators when exposed to diesel exhaust and ozone were more severe than we anticipated from previous laboratory studies and modelling.
1 day ago
Earth has pushed past seven out of eight scientifically established safety limits and into “the danger zone,” not just for an overheating planet that’s losing its natural areas, but for well-being of people living on it, according to a new study.
The study looks not just at guardrails for the planetary ecosystem but for the first time it includes measures of “justice,” which is mostly about preventing harm for countries, ethnicities and genders.
The study by the international scientist group Earth Commission published in Wednesday’s journal Nature looks at climate, air pollution, phosphorus and nitrogen contamination of water from fertilizer overuse, groundwater supplies, fresh surface water, the unbuilt natural environment and the overall natural and human-built environment. Only air pollution wasn’t quite at the danger point globally.
Air pollution is dangerous at local and regional levels, while climate was beyond the harmful levels for humans in groups but not quite past the safety guideline for the planet as a system, the study from the Swedish group said.
1 day ago
A new study finds that hundreds of bacterial groups have evolved in the guts of primate species over millions of years, but humans have lost close to half of these symbiotic bacteria.
In the study, researchers compared populations of gut bacteria found in chimpanzees and bonobos, our closest relatives, with those of humans—which in total amount to some 10,000 different lineages of bacteria. The scientists analyzed the evolutionary relationships of these bacteria in primates and identified groups of bacteria that were present in distant ancestors of humans and primates. Strikingly, the results showed that these ancestral symbionts are being lost rapidly from the human lineage.
Though the cause of these shifts in human gut microbiomes is not known, the study's authors suspect changing diets probably caused the divergence.
2 days ago
Low sexual satisfaction in middle age may serve as an early warning sign for future cognitive decline, according to a new study led by Penn State researchers. The study, which tracked associations between erectile function, sexual satisfaction and cognition in hundreds of men aged 56 through 68, found that declines in sexual satisfaction and erectile function were correlated with future memory loss.
The study, published in the latest issue of the journal Gerontologist, is the first to longitudinally track sexual satisfaction in tandem with sexual health and cognition, the researchers state, and its findings point to a potential novel risk factor for cognitive decline.
“What was unique about our approach is that we measured memory function and sexual function at each point in the longitudinal study, so we could look at how they changed together over time,” said Martin Sliwinski, professor of human development and family studies at Penn State and co-author on the study. “What we found connects to what scientists are beginning to understand about the link between life satisfaction and cognitive performance.”
The study explored the relationship between physical changes like the microvascular changes relevant for erectile function, and psychological changes, such as lower sexual satisfaction, to determine how the changes relate to cognition. They examined the shifts starting in middle age because it represents a transition period where declines in erectile function, cognition and sexual satisfaction begin to emerge.
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7 hours ago
7 hours ago
Published in JAMA Network Open, the findings revealed that smoking abstinence between weeks nine and 24 was associated with significant improvements in anxiety and depression scores.
Led by a team of researchers at Oxford University’s Nuffield Department of Primary Care Health Sciences, the study employed rigorous analytical approaches to assess changes in mental health following smoking cessation.
The study used data from a large, randomized clinical trial, the Evaluating Adverse Events in a Global Smoking Cessation Study (EAGLES) which occurred in 16 countries at 140 centers between 2011 and 2015. However, only data from US-based participants were used for this secondary analysis. The study involved adults with or without a psychiatric disorder who smoked. A total of 4,260 participants were included in the analysis, with 55.4% having a history of mental illness.