4,783 research outputs found
Fluoroquinolone-Resistant Campylobacter Isolates from Conventional and Antibiotic-Free Chicken Products
The use of fluoroquinolones (FQs) in poultry production is an important issue in public health today. In February 2002, two prominent U.S. poultry companies pledged to stop using FQs for flock-wide treatment. One year later, we began a survey of Campylobacter isolates on chicken products from these two companies and from two producers claiming total abstention from antibiotic use. Using both standard isolation methods and new methods modified to enhance detection of FQ-resistant Campylobacter, we compared rates of FQ-resistant Campylobacter among these products. Four major findings were drawn from this study: a) antibiotic-free brands were not more likely to be contaminated with Campylobacter; b) a high percentage of products from the two conventional brands were contaminated with FQ-resistant Campylobacter (43 and 96%); c) these conventional brands had significantly higher odds of carrying resistant strains compared with antibiotic-free products; and d) supplementing media with FQs increased the sensitivity of detecting FQ-resistant strains among mixed populations of Campylobacter, thus reducing a bias toward underestimating the prevalence of FQ-resistant Campylobacter on samples. These results suggest that FQ resistance may persist in the commercial poultry environment in the absence of FQ-selective pressure and that these strains contaminate a larger proportion of foods than reported previously
Menstrual Dignity and the Bar Exam
This Article examines the issue of menstruation and the administration of the bar exam. Although such problems are not new, over the summer and fall of 2020, test takers and commentators took to social media to critique state board of law examinersâ (âBOLEâ) policies regarding menstruation. These problems persist. Menstruators worry that if they unexpectedly bleed during the exam, they may not have access to appropriately sized and constructed menstrual products or may be prohibited from accessing the bathroom. Personal products that are permitted often must be carried in a clear, plastic bag. Some express privacy concerns that the see-through bag outs test takersâ menstruation as well as their birth-assigned sex â an especially difficult problem for transgender, genderqueer/nonbinary, and intersex individuals who do not wish to share that information.The authors conducted a study documenting experiences with menstruation and the bar exam and examined BOLE policies and practices relevant to menstruation. The Article uses the data from these studies to delineate the contours and substance of the problem. To guide this analysis, the Article also analyzes BOLE policies under the Equal Protection Clause and local human rights laws, determining that current policies are likely unconstitutional and discriminatory. Finally, the Article proposes a comprehensive Model Policy that appropriately balances BOLE concerns against the important principles of privacy and respect, fairness and non-discrimination, promoting health, providing accommodations, and transparency. If adopted, the Model Policy would bring BOLE policies closer to the goals of the critical intersectional movements urging diversification of the legal profession, bar exam reform, and menstrual justice
Forest Cover Associated with Improved Child Health and Nutrition: Evidence from the Malawi Demographic and Health Survey and Satellite Data
Healthy forests provide human communities with a host of important ecosystem services, including the provision of food, clean water, fuel, and natural medicines. Yet globally, about 13 million hectares of forests are lost every year, with the biggest losses in Africa and South America. As biodiversity loss and ecosystem degradation due to deforestation continue at unprecedented rates, with concomitant loss of ecosystem services, impacts on human health remain poorly understood. Here, we use data from the 2010 Malawi Demographic and Health Survey, linked with satellite remote sensing data on forest cover, to explore and better understand this relationship. Our analysis finds that forest cover is associated with improved health and nutrition outcomes among children in Malawi. Children living in areas with net forest cover loss between 2000 and 2010 were 19% less likely to have a diverse diet and 29% less likely to consume vitamin A-rich foods than children living in areas with no net change in forest cover. Conversely, children living in communities with higher percentages of forest cover were more likely to consume vitamin A-rich foods and less likely to experience diarrhea. Net gain in forest cover over the 10-year period was associated with a 34% decrease in the odds of children experiencing diarrhea (P5.002). Given that our analysis relied on observational data and that there were potential unknown factors for which we could not account, these preliminary findings demonstrate only associations, not causal relationships, between forest cover and child health and nutrition outcomes. However, the findings raise concerns about the potential short- and long-term impacts of ongoing deforestation and ecosystem degradation on community health in Malawi, and they suggest that preventing forest loss and maintaining the ecosystems services of forests are important factors in improving human health and nutrition outcomes
Extraction efficiency and quantification of dissolved metabolites in targeted marine metabolomics
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Limnology and Oceanography: Methods 15 (2017): 417â428, doi:10.1002/lom3.10181.The field of metabolomics seeks to characterize the suite of small molecules that comprise the end-products of cellular regulation. Metabolomics has been used in biomedical applications as well as environmental studies that explore ecological and biogeochemical questions. We have developed a targeted metabolomics method using electrospray ionizationâliquid chromatography tandem mass spectrometry to analyze metabolites dissolved in seawater. Preparation of samples from the marine environment presents challenges because dilute metabolites must be concentrated and desalted. We present the extraction efficiencies of 89 metabolites in our targeted method using solid phase extraction (SPE). In addition, we calculate the limits of detection and quantification for the metabolites in the method and compare the instrument response factors in five different matrices ranging from deionized water to spent medium from cultured marine microbes. High background organic matter content reduces the instrument response factor for only a small group of metabolites, yet enhances the extraction efficiency for other metabolites on the SPE cartridge used here, a modified styrene-divinylbenzene polymer called PPL. Aromatic or larger uncharged compounds, in particular, are reproducibly well retained on the PPL polymer. This method is suitable for the detection of dissolved metabolites in marine samples, with limits of detection ranging fromâ<â1 pM to ⌠2 nM dependent on the dual impacts of seawater matrix on extraction efficiency and on instrument response factors.Gordon and Betty Moore Foundation Grant Number: 3304;
National Science Foundation Grant Number: OCE-1154320;
Simons Foundation Internationa
Evidence for quorum sensing and differential metabolite production by a marine bacterium in response to DMSP
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in The ISME Journal 10 (2016): 2304â2316, doi:10.1038/ismej.2016.6.Microbes, the foundation of the marine foodweb, do not function in isolation, but rather rely on molecular level interactions among species to thrive. Although certain types of interactions between autotrophic and heterotrophic microorganisms have been well documented, the role of specific organic molecules in regulating inter-species relationships and supporting growth are only beginning to be understood. Here, we examine one such interaction by characterizing the metabolic response of a heterotrophic marine bacterium, Ruegeria pomeroyi DSS-3, to growth on dimethylsulfoniopropionate (DMSP), an abundant organosulfur metabolite produced by phytoplankton. When cultivated on DMSP, R. pomeroyi synthesized a quorum-sensing molecule, N-(3-oxotetradecanoyl)-l-homoserine lactone, at significantly higher levels than during growth on propionate. Concomitant with the production of a quorum-sensing molecule, we observed differential production of intra- and extracellular metabolites including glutamine, vitamin B2 and biosynthetic intermediates of cyclic amino acids. Our metabolomics data indicate that R. pomeroyi changes regulation of its biochemical pathways in a manner that is adaptive for a cooperative lifestyle in the presence of DMSP, in anticipation of phytoplankton-derived nutrients and higher microbial density. This behavior is likely to occur on sinking marine particles, indicating that this response may impact the fate of organic matter.This research is funded in part by the Gordon and Betty Moore Foundation through Grant GBMF3304 as well as by the National Science Foundation (Grants OCE-0928424 and OCE-1154320)
Exploring Womenâs Oxytocin Responses to Interactions With Their Pet Cats
Background. Extensive research has evaluated the involvement of the neuropeptide oxytocin (OT) in human social behaviors, including parent-infant relationships. Studies have investigated OTâs connection to human attachment to nonhuman animals, with the majority of the literature focusing on domestic dogs (Canis lupis familiaris). Utilizing what is known about OT and its role in maternal-infant and human-dog bonding, we apply these frameworks to the study of human-domestic cat (Felis catus) interactions. Methods. We investigated changes in salivary OT levels in 30 U.S. women of reproductive age before and after two conditions: reading a book (control) and interacting with their pet cat. Participant and cat behavioral patterns during the cat interaction condition were also quantified to determine if differences in womenâs OT concentrations were associated with specific human and cat behaviors. Results. Our results revealed no changes in womenâs OT levels during the cat interaction, relative to the control condition, and pre-cat interaction OT levels. However, differences in womenâs OT concentrations were correlated with some human-cat interactions (e.g., positively with petting cat and cat approach initiation, negatively with cat agonistic behavior) but not all observed behaviors (e.g., use of gentle or baby voice) coded during human-cat interactions. Discussion. This study is the first to explore womenâs OT in response to interactions with their pet cat and has identified distinct human and cat behaviors that influence OT release in humans
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