How a butterfly tree becomes a web
2021-07-16
(Press-News.org) Evolution is often portrayed as a tree, with new species branching off from existing lineages, never again to meet. The truth however is often much messier. In the case of adaptive radiation, in which species diversify rapidly to fill different ecological niches, it can be difficult to resolve relationships, and the phylogeny (i.e. evolutionary tree) may look more like a bush than a tree. This is because lineages may continue to interbreed as new species are established, and/or they may diverge and then re-hybridize, resulting in genetically mixed populations (known as admixture). Even after species diverge, the introduction of genes from one species to another (known as introgression) can occur. All of this results in a network of related species, rather than a simple tree. The extent to which these processes occur and their evolutionary and genomic impacts are not well understood, partially due to the "tree-like" assumptions of the models that are used to construct phylogenies. In a new study in Genome Biology and Evolution titled END
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Common COVID-19 antibiotic no more effective than placebo
2021-07-16
A UC San Francisco study has found that the antibiotic azithromycin was no more effective than a placebo in preventing symptoms of COVID-19 among non-hospitalized patients, and may increase their chance of hospitalization, despite widespread prescription of the antibiotic for the disease.
"These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection," said lead author Catherine E. Oldenburg, ScD, MPH, an assistant professor with the UCSF Proctor Foundation. SARS-CoV-2 is the virus that causes COVID-19.
Azithromycin, a broad-spectrum antibiotic, is widely prescribed as a treatment for COVID-19 in the United States and the rest of the world. "The hypothesis is that it has anti-inflammatory properties that ...
Artificial sweeteners enable delivery of carbon monoxide to treat organ injury
2021-07-16
ATLANTA--An oral prodrug developed by a team of scientists led by Binghe Wang, Regents' Professor of Chemistry at Georgia State University, delivers carbon monoxide to protect against acute kidney injury, according to a new paper published in Chemical Science.
Although carbon monoxide (CO) gas is toxic in large doses, scientists have discovered it can have beneficial effects by reducing inflammation and protecting cells against injury. Previous studies have demonstrated the protective effects of CO against injury in the kidneys, lungs, gastrointestinal tract and liver, among other organs. For the past five years, Wang and his collaborators have worked to design a safe way to deliver CO to human patients via prodrugs -- inactive compounds that ...
From birth control to mammograms, many women missed out on preventive care for all of 2020
2021-07-16
The COVID-19 pandemic knocked many women off schedule for important health appointments, a new study finds, and many didn't get back on schedule even after clinics reopened. The effect may have been greatest in areas where such care is already likely falling behind experts' recommendations.
The study, by health care researchers in the University of Michigan END ...
Study examines the role of deep-sea microbial predators at hydrothermal vents
2021-07-16
The hydrothermal vent fluids from the Gorda Ridge spreading center in the northeast Pacific Ocean create a biological hub of activity in the deep sea. There, in the dark ocean, a unique food web thrives not on photosynthesis but rather on chemical energy from the venting fluids. Among the creatures having a field day feasting at the Gorda Ridge vents is a diverse assortment of microbial eukaryotes, or protists, that graze on chemosynthetic bacteria and archaea.
This protistan grazing, which is a key mechanism for carbon transport and recycling in microbial food webs, exerts a higher predation pressure at hydrothermal vent sites than in the surrounding deep-sea environment, a new paper finds.
"Our ...
COVID-19 vaccination: Examining negative dominance on social media
2021-07-16
Vaccine negativity and reluctance didn't just emerge during the COVID-19 pandemic. In a recent study published in the Disaster Medicine and Public Health Preparedness journal, authors from Loyola University Maryland and Johns Hopkins Bloomberg School of Public Health explored the appearance of negative dominance - a concept in which negative messages outweigh positive, solution-oriented messages in audiences' perceptions - in the context of COVID-19 vaccine-related information and activity online.
Prior research has looked at media coverage to identify vaccine concerns among the public and its impact on vaccine-related beliefs and behaviors, the spread of misinformation and fake news on the Internet, and the role ...
SUV39H2: A direct genetic link to autism spectrum disorders
2021-07-16
New research from the RIKEN Center for Brain Science (CBS) in Japan shows that a deficit in histone methylation could lead to the development of autism spectrum disorders (ASD). A human variant of the SUV39H2 gene led researchers to examine its absence in mice. Published in Molecular Psychiatry, the study found that when absent, adult mice exhibited cognitive inflexibility similar to what occurs in autism, and embryonic mice showed misregulated expression of genes related to brain development. These findings represent the first direct link between the SUV39H2 gene and ASD.
Genes are turned ...
Primary care payment model, telemedicine use for Medicare Advantage during pandemic
2021-07-16
What The Study Did: The association between primary care payment models and the use of telemedicine for Medicare Advantage enrollees during the COVID-19 pandemic was examined in this study.
Authors: Brian W. Powers, M.D., M.B.A., of Humana Inc. in Louisville, Kentucky, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamahealthforum.2021.1597)
Editor's Note: The article includes conflicts of interest disclosures. Please see the article for additional information, including other authors, author ...
Outcomes of patients treated by female vs male physicians
2021-07-16
What The Study Did: Researchers investigated whether death, other hospital outcomes and processes of care differed between patients cared for by female and male physicians at hospitals in Canada.
Authors: Fahad Razak, M.D., M.Sc., of the University of Toronto in Ontario, Canada, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamahealthforum.2021.1615)
Editor's Note: The article includes conflicts of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.
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Media advisory: The full study is linked to this news ...
Exploring gap between excess mortality, COVID-19 deaths in 67 countries
2021-07-16
What The Study Did: National health care systems have different capacities to correctly identify people who died of COVID-19. Researchers in this study analyzed the gap between excess mortality and COVID-19 confirmed mortality in 67 countries to determine the extent to which official data on COVID-19 deaths might be considered reliable.
Authors: Davide Golinelli, M.D., Alma Mater Studiorum-University of Bologna in Italy, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamanetworkopen.2021.17359)
Editor's ...
No sign of COVID-19 vaccine in breast milk
2021-07-16
Messenger RNA vaccines against COVID-19 were not detected in human milk, according to a small study by UC San Francisco, providing early evidence that the vaccine mRNA is not transferred to the infant.
The study, which analyzed the breast milk of seven women after they received the mRNA vaccines and found no trace of the vaccine, offers the first direct data of vaccine safety during breastfeeding and could allay concerns among those who have declined vaccination or discontinued breastfeeding due to concern that vaccination might alter human milk. The paper appears in JAMA Pediatrics.
Research has demonstrated that vaccines with mRNA inhibit transmission ...