PNAS (Chemistry)

Societal stereotypes depict girls as less interested than boys in computer science and engineering. We demonstrate the existence of these stereotypes among children and adolescents from first to 12th grade and their potential negative consequences for girls’ subsequent participation in these fields. Studies 1 and 2 (n = 2,277; one…

Published in: "PNAS".

Responsible stewardship of temperate forests can address key challenges posed by climate change through sequestering carbon, producing low-carbon products, and mitigating climate risks. Forest thinning and fuel reduction can mitigate climate-related risks like catastrophic wildfire. These treatments are often cost prohibitive, though, in part because of low demand for low-value…

Published in: "PNAS".

The beginning of understanding sperm biology coincided with the design and invention of the light microscope in 1677 by Antonie van Leeuwenhoek. He was the first person to observe sperm cells, and described them as “small animals,” because they move! Indeed, motility is one of the essential features of sperm…

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Among CD4+ T cells, T helper 17 (Th17) cells are particularly susceptible to HIV-1 infection and are depleted from mucosal sites, which causes damage to the gut barrier, resulting in a microbial translocation-induced systemic inflammation, a hallmark of disease progression. Furthermore, a proportion of latently infected Th17 cells persist long…

Published in: "PNAS".

The hippocampus is essential for consolidating transient experiences into long-lasting memories. Memory consolidation is facilitated by postlearning sleep, although the underlying cellular mechanisms are largely unknown. We took an unbiased approach to this question by using a mouse model of hippocampally mediated, sleep-dependent memory consolidation (contextual fear memory). Because synaptic…

Published in: "PNAS".

Lipid membranes are complex quasi–two-dimensional fluids, whose importance in biology and unique physical/materials properties have made them a major target for biophysical research. Recent single-molecule tracking experiments in membranes have caused some controversy, calling the venerable Saffman–Delbrück model into question and suggesting that, perhaps, current understanding of membrane hydrodynamics is…

Published in: "PNAS".

Understanding the functional role of protein-excited states has important implications in protein design and drug discovery. However, because these states are difficult to find and study, it is still unclear if excited states simply result from thermal fluctuations and generally detract from function or if these states can actually enhance…

Published in: "PNAS".

The COVID-19 pandemic has led to an increased demand for single-use plastics that intensifies pressure on an already out-of-control global plastic waste problem. While it is suspected to be large, the magnitude and fate of this pandemic-associated mismanaged plastic waste are unknown. Here, we use our MITgcm ocean plastic model…

Published in: "PNAS".

Lipofuscin granules enclose mixtures of cross-linked proteins and lipids in proportions that depend on the tissue analyzed. Retinal lipofuscin is unique in that it contains mostly lipids with very little proteins. However, retinal lipofuscin also presents biological and physicochemical characteristics indistinguishable from conventional granules, including indigestibility, tendency to cause lysosome…

Published in: "PNAS".

A prevailing paradigm suggests that species richness increases with area in a decelerating way. This ubiquitous power law scaling, the species–area relationship, has formed the foundation of many conservation strategies. In spatially complex ecosystems, however, the area may not be the sole dimension to scale biodiversity patterns because the scale-invariant…

Published in: "PNAS".

Zika virus (ZIKV) during pregnancy infects fetal trophoblasts and causes placental damage and birth defects including microcephaly. Little is known about the anti-ZIKV cellular immune response at the maternal–fetal interface. Decidual natural killer cells (dNK), which directly contact fetal trophoblasts, are the dominant maternal immune cells in the first-trimester placenta,…

Published in: "PNAS".

The perception that cannabis can be safely consumed without health risks or that use is safer than alternative recreational drugs is perhaps an unintended consequence of recent marijuana legalization campaigns in the United States and other countries. Often missing in the debates about cannabis legalization is the potential harm caused…

Published in: "PNAS".