1,145 research outputs found

    Health Impacts at the Advent of Agriculture

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    The transition from a hunting and gathering lifestyle to one based in agriculture may have been the most crucial development made by past peoples, transforming not only diet, but social structure, mobility, and resource use. I present human skeletal evidence illustrating the consequences of agriculture on human health using case studies from prehistoric Mesoamerica, the American southwest, and regions in Asia. Such evidence has indicated that intensification of maize agriculture in the New World correlates with increased infant mortality rate, dental caries, iron-deficiency anemia, and an overall decline in general health while these health problems have little to no correlation to early intensification of rice agriculture in Asia. This is likely due to the decreased cariogenic nature of rice and its greater nutritional value compared to maize. Other possible causes include processing differences and greater dietary variety in Asia

    Comparing the selective and co-selective effects of different antimicrobials in bacterial communities

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    This is the author accepted manuscript. The final version is available on open access from Elsevier via the DOI in this recordBacterial communities are exposed to a cocktail of antimicrobial agents, including antibiotics, heavy metals and biocidal antimicrobials such as quaternary ammonium compounds (QACs). The extent to which these compounds may select or co-select for antimicrobial resistance (AMR) is not fully understood. In this study, human associated, wastewater derived, bacterial communities were exposed to either benzalkonium chloride (BAC), ciprofloxacin or trimethoprim at sub-point of use concentrations for one week, in order to determine selective and co-selective potential. Metagenome analyses were performed to determine effects on bacterial community structure and prevalence of antibiotic resistance genes (ARGs) and metal or biocide resistance genes (MBRGS). Ciprofloxacin had the greatest co-selective potential, significantly enriching for resistance mechanisms to multiple antibiotic classes. Conversely, BAC exposure significantly reduced relative abundance of ARGs and MBRGS, including the well characterised qac efflux genes. However, BAC exposure significantly impacted bacterial community structure. This suggests BAC and potentially other QACs did not play as significant a role in co-selection for AMR relative to antibiotics such as ciprofloxacin at below point of use concentrations in this study. This approach can be used to identify priority compounds for further study, to better understand evolution of AMR in bacterial communities exposed to sub-point of use concentrations of antimicrobials.Natural Environment Research Council (NERC)Biotechnology and Biological Sciences Research Council (BBSRC

    NMR shim coil design utilising a rapid spherical harmonic calculation method

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    A rapid spherical harmonic calculation method is used for the design of Nuclear Magnetic Resonance shim coils. The aim is to design each shim such that it generates a field described purely by a single spherical harmonic. By applying simulated annealing techniques, coil arrangements are produced through the optimal positioning of current-carrying circular arc conductors of rectangular cross-section. This involves minimizing the undesirable harmonies in relation to a target harmonic. The design method is flexible enough to be applied for the production of coil arrangements that generate fields consisting significantly of either zonal or tesseral harmonics. Results are presented for several coil designs which generate tesseral harmonics of degree one

    Integrating human and environmental health in antibiotic risk assessment: A critical analysis of protection goals, species sensitivity and antimicrobial resistance

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    This is the author accepted manuscriptAntibiotics are vital in the treatment of bacterial infectious diseases but when released into the environment they may impact non-target organisms that perform vital ecosystem services and enhance antimicrobial resistance development with significant consequences for human health. We evaluate whether the current environmental risk assessment regulatory guidance is protective of antibiotic impacts on the environment, protective of antimicrobial resistance, and propose science-based protection goals for antibiotic manufacturing discharges. A review and meta-analysis was conducted of aquatic ecotoxicity data for antibiotics and for minimum selective concentration data derived from clinically relevant bacteria. Relative species sensitivity was investigated applying general linear models, and predicted no effect concentrations were generated for toxicity to aquatic organisms and compared with predicted no effect concentrations for resistance development. Prokaryotes were most sensitive to antibiotics but the range of sensitivities spanned up to several orders of magnitude. We show reliance on one species of (cyano)bacteria and the ā€˜activated sludge respiration inhibition testā€™ is not sufficient to set protection levels for the environment. Individually, neither traditional aquatic predicted no effect concentrations nor predicted no effect concentrations suggested to safeguard for antimicrobial resistance, protect against environmental or human health effects (via antimicrobial resistance development). Including data from clinically relevant bacteria and also more species of environmentally relevant bacteria in the regulatory framework would help in defining safe discharge concentrations for antibiotics for patient use and manufacturing that would protect environmental and human health. It would also support ending unnecessary testing on metazoan species.AstraZeneca Global SHE Research Programm

    Evolution of antibiotic resistance at low antibiotic concentrations including selection below the minimal selective concentration

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: The datasets associated with Figs. 1ā€“6 are included in this published article as a Supplementary Data file. Metagenome sequence files have been deposited in the European Nucleotide Archive. Accession number: PRJEB38942.Code availability: Code used for metagenome analysis: FastQC; MultiQC; FLASH2; Metaphlan2; Hclust2 and ARGs-OAP v2.Determining the selective potential of antibiotics at environmental concentrations is critical for designing effective strategies to limit selection for antibiotic resistance. This study determined the minimal selective concentrations (MSCs) for macrolide and fluoroquinolone antibiotics included on the European Commission's Water Framework Directive's priority hazardous substancesĀ Watch List. The macrolides demonstrated positive selection for ermF at concentrations 1-2 orders of magnitude greater (>500 and 7.8 and <15.6ā€‰Āµg/L). This highlights the need for compound specific assessment of selective potential. In addition, a sub-MSC selective window defined by the minimal increased persistence concentration (MIPC) is described. Differential rates of negative selection (or persistence) were associated with elevated prevalence relative to the no antibiotic control below the MSC. This increased persistence leads to opportunities for further selection over time and risk of human exposure and environmental transmission.Biotechnology and Biological Sciences Research Council (BBSRC)Natural Environment Research Council (NERC

    The effect of biologging devices on reproduction, growth and survival of adult sea turtles

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    This is the final version. Available from BMC via the DOI in this record.The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.Background Telemetry and biologging systems, ā€˜trackingā€™ hereafter, have been instrumental in meeting the challenges associated with studying the ecology and behaviour of cryptic, wide-ranging marine mega-vertebrates. Over recent decades, globally, sea turtle tracking has increased exponentially, across species and life-stages, despite a paucity of studies investigating the effects of such devices on study animals. Indeed, such studies are key to informing whether data collected are unbiased and, whether derived estimates can be considered typical of the population at large. Methods Here, using a 26-year individual-based monitoring dataset on sympatric green (Chelonia mydas) and loggerhead (Caretta caretta) turtles, we provide the first analysis of the effects of device attachment on reproduction, growth and survival of nesting females. Results We found no significant difference in growth and reproductive correlates between tracked and non-tracked females in the years following device attachment. Similarly, when comparing pre- and post-tracking data, we found no significant difference in the reproductive correlates of tracked females for either species or significant carry-over effects of device attachment on reproductive correlates in green turtles. The latter was not investigated for loggerhead turtles due to small sample size. Finally, we found no significant effects of device attachment on return rates or survival of tracked females for either species. Conclusion While there were no significant detrimental effects of device attachment on adult sea turtles in this region, our study highlights the need for other similar studies elsewhere and the value of long-term individual-based monitoring

    Mapping the methodological quality of international primary-secondary transitions research literature : A systematic methodological review.

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    Funding Information This article is partly based on a study funded by the Scottish Government (PI Jindal-Snape; CI Cantali; CI MacGillivray; CI Hannah).Peer reviewe
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