2,913 research outputs found

    Anthropogenic impacts on mosquito populations in North America over the past century.

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    The recent emergence and spread of vector-borne viruses including Zika, chikungunya and dengue has raised concerns that climate change may cause mosquito vectors of these diseases to expand into more temperate regions. However, the long-term impact of other anthropogenic factors on mosquito abundance and distributions is less studied. Here, we show that anthropogenic chemical use (DDT; dichlorodiphenyltrichloroethane) and increasing urbanization were the strongest drivers of changes in mosquito populations over the last eight decades in areas on both coasts of North America. Mosquito populations have increased as much as tenfold, and mosquito communities have become two- to fourfold richer over the last five decades. These increases are correlated with the decay in residual environmental DDT concentrations and growing human populations, but not with temperature. These results illustrate the far-reaching impacts of multiple anthropogenic disturbances on animal communities and suggest that interactions between land use and chemical use may have unforeseen consequences on ecosystems

    Seasonal variation and impact of waste-water lagoons as larval habitat on the population dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at two dairy farms in northern California.

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    The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012- to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the "overwintering" of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and dispersal of Culicoides midges is essential for the creation of models to predict BTV infection of livestock and to develop sound abatement strategies

    Analysis of virus genomes from glacial environments reveals novel virus groups with unusual host interactions

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    Microbial communities in glacial ecosystems are diverse, active, and subjected to strong viral pressures and infection rates. In this study we analyse putative virus genomes assembled from three dsDNA viromes from cryoconite hole ecosystems of Svalbard and the Greenland Ice Sheet to assess the potential hosts and functional role viruses play in these habitats. We assembled 208 million reads from the virus-size fraction and developed a procedure to select genuine virus scaffolds from cellular contamination. Our curated virus library contained 546 scaffolds up to 230 Kb in length, 54 of which were circular virus consensus genomes. Analysis of virus marker genes revealed a wide range of viruses had been assembled, including bacteriophages, cyanophages, nucleocytoplasmic large DNA viruses and a virophage, with putative hosts identified as Actinobacteria, Alphaproteobacteria, Cyanobacteria, Firmicutes, Gammaproteobacteria, eukaryotic algae and amoebae. Whole genome comparisons revealed the majority of circular genome scaffolds formed 12 novel groups, two of which contained multiple phage members with plasmid-like properties, including a group of phage-plasmids possessing plasmid-like partition genes and toxin-antitoxin addiction modules to ensure their replication and a satellite phage-plasmid group. Surprisingly we also assembled a phage that not only encoded plasmid partition genes, but a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas adaptive bacterial immune system. One of the spacers was an exact match for another phage in our virome, indicating that in a novel use of the system, the lysogen was potentially capable of conferring immunity on its bacterial host against other phage. Together these results suggest that highly novel and diverse groups of viruses are present in glacial environments, some of which utilise very unusual life strategies and genes to control their replication and maintain a long-term relationship with their hosts

    Increased utilization of total joint arthroplasty after Medicaid expansion

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    BACKGROUND: The expansion of state Medicaid programs under the U.S. Affordable Care Act has led to a dramatic increase in the number of Americans with health insurance coverage. Prior analyses of a limited number of states have suggested that greater utilization of total hip arthroplasty (THA) and total knee arthroplasty (TKA) should be expected after Medicaid expansion. The purpose of our study was to examine whether increased utilization of THA and TKA occurred across a broader range of states after Medicaid expansion. METHODS: We analyzed administrative data from the Healthcare Cost and Utilization Project from 9 states (Arkansas, Arizona, Colorado, Iowa, Massachusetts, Maryland, Nevada, New York, and Vermont) that expanded Medicaid in 2014 and 2 states that did not expand Medicaid (Florida and Missouri). We included patients who were 18 to 64 years of age and had a primary THA or TKA from 2012 to 2015 with Medicaid as the primary payer. Other payers (including dual-eligible Medicaid and Medicare beneficiaries) were excluded. We performed multivariable regression modeling with the number of Medicaid-insured THAs or TKAs as the dependent variable and the interaction between the state Medicaid expansion status and year as the main policy independent variable, with adjustment for community characteristics. RESULTS: Among all 11 states, there were 39,452 total joint arthroplasties (42% THA and 58% TKA) funded by Medicaid from 2012 to 2015. After adjusting for community characteristics, within expansion states, compared with 2013, THA and TKA increased 15% in 2014 (p \u3c 0.0001) and 23% in 2015 (p \u3c 0.0001) within expansion states. Within non-expansion states, compared with 2013, there were significant utilization decreases of 18% in 2014 (p \u3c 0.0001) and 11% in 2015 (p = 0.0002). CONCLUSIONS: Medicaid expansion was associated with significant increases in Medicaid-funded THA and TKA utilization in 9 states. As additional states consider expanding Medicaid programs and as alternative health reforms that increase insurance eligibility are debated, surgeons, administrators, and policymakers should prepare for a surge in the utilization of THA and TKA

    AMR policy dialogue : driving innovative solutions for antimicrobial discovery

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    Antimicrobial resistance (AMR) is a global strategic priority and sits within the UK Government’s National Risk Register. By 2050, AMR is predicted to cause 10 million deaths, more than cancer. In 2019 alone, there were an estimated 4.95 million deaths associated with bacterial AMR. Although global pharmaceutical research and development (R&D) spend continues to increase year on year, research into antimicrobial drug discovery is not currently an attractive commercial investment. This has had two major consequences: an ongoing decline of human capital for R&D in this field, and a decline over the longer term in availability of therapeutically effective antibiotics and other antimicrobial agents. Concerted and coordinated efforts are needed to translate high-level policy commitments into strategic actions for long-term funding and support for the R&D of new antimicrobials

    Early Life Socioeconomic Circumstance and Late Life Brain Hyperintensities : A Population Based Cohort Study

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    Funding: Image acquisition and image analysis for this study was funded by the Alzheimer's Research Trust (now Alzheimer's Research UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments The authors would like to thank the participants of the Aberdeen 1936 Birth Cohort (ABC36), without whom this research would not have been possible.Peer reviewedPublisher PD
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