Publications by authors named "W R Hartman"

Seawater intrusion into freshwater wetlands causes changes in microbial communities and biogeochemistry, but the exact mechanisms driving these changes remain unclear. Here we use a manipulative laboratory microcosm experiment, combined with DNA sequencing and biogeochemical measurements, to tease apart the effects of sulfate from other seawater ions. We examined changes in microbial taxonomy and function as well as emissions of carbon dioxide, methane, and nitrous oxide in response to changes in ion concentrations.

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The impact of cancer cachexia on the colonic microbiota is poorly characterized. This study assessed the effect of two cachectic-producing tumor types on the gut microbiota to determine if a similar dysbiosis could be found. In addition, it was determined if a diet containing an immunonutrient-rich food (walnuts) known to promote the growth of probiotic bacteria in the colon could alter the dysbiosis and slow cachexia.

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Estuarine wetlands harbor considerable carbon stocks, but rising sea levels could affect their ability to sequester soil carbon as well as their potential to emit methane (CH). While sulfate loading from seawater intrusion may reduce CH production due to the higher energy yield of microbial sulfate reduction, existing studies suggest other factors are likely at play. Our study of 11 wetland complexes spanning a natural salinity and productivity gradient across the San Francisco Bay and Delta found that while CH fluxes generally declined with salinity, they were highest in oligohaline wetlands (ca.

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Article Synopsis
  • - The nasal mucosa is a key defense point against SARS-CoV-2, but vaccines given through injections typically don't produce strong antibody responses there.
  • - In a study of over 3,000 participants, researchers found that after getting the AZD1222 vaccine, detectable levels of IgG antibodies were present in nasal fluid, especially after the second dose, and these were correlated with serum IgG levels.
  • - The vaccine led to a strong immune response, with significant enhancements in nasal IgG levels that associated with decreased viral loads and shorter shedding durations during breakthrough infections.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019. To date, this coronavirus is responsible for greater than 90 million cases in the United States and more than 1 million confirmed deaths. When this virus came to the United States, testing was unorganized, no effective treatments were known, and no vaccines had been discovered.

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