272 research outputs found

    Impact of a Major Inflow Event on the Composition and Distribution of Bacterioplankton Communities in the Baltic Sea

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    Major Baltic inflow (MBI) events carry highly saline water from the North Sea to the central Baltic Sea and thereby affect both its environmental conditions and its biota. While bacterioplankton communities in the Baltic Sea are strongly structured by salinity, how MBIs impact the composition and distribution of bacteria is unknown. The exceptional MBI in 2014, which brought saline and oxygenated water into the basins of the central Baltic Sea, enabled the linkage of microbiological investigations to hydrographic and modeling studies of this MBI. Using sequence data of 16S ribosomal RNA (rRNA) and 16S rRNA genes (rDNA), we analyzed bacterioplankton community composition in the inflowing water and in the uplifted former bottomwater at stations reached by the MBI. Bacterial diversity data were compared with respective data obtained from previous, non-inflow conditions. Changes in bacterial community composition following the 2014 MBI were mainly apparent at the genus level. A number of specific taxa were enriched in the inflowing water, with large changes in the rRNA/rDNA ratios indicating the different activity levels between of the water masses. The relative similarity of the bacterial communities in the inflowing and uplifted waters as well as the results from an inflow-simulating numerical model showed that the inflowing water did not originate directly from the North Sea but mostly from adjacent areas in the Baltic Sea. This suggested that the inflow event led to a series of shifts in Baltic Sea water masses among the Baltic Sea basins and a gradual mixing of the water bodies. Dramatic changes in the bacterial community composition occurred when the bottomwater inflow reached the anoxic, sulfidic deep basins, resulting in an uplifting of the formerly anoxic bacterial community, dominated by Epsilonproteobacteria. Our study of the impact of MBIs on bacterioplankton communities therefore highlights two relevant underlying mechanisms that impact the distribution and possibly also the activities of planktonic bacteria in the Baltic Sea: (1) the successive dilution of inflowing North Sea water with ambient waters and (2) the uplifting of former bottom-water communities to higher water strata.This work was funded by the Deutsche Forschungsgemeinschaft (DFG) (projects JU367/15-1, JU367/16-1 to KJ and LA1466/8- 1 to ML). DH was supported by the European Regional Development Fund and the Estonian Research Council Mobilitas Plus Top Researcher grant “MOBTT24.” UG was supported by the BMBF project “Hydrodynamic observations and simulations of munition in the sea,” a subproject of the collaborative project “Environmental monitoring for the delaboration of munitions in the sea” (Grant No. #03F0747C).This work was funded by the Deutsche Forschungsgemeinschaft (DFG) (projects JU367/15-1, JU367/16-1 to KJ and LA1466/8- 1 to ML). DH was supported by the European Regional Development Fund and the Estonian Research Council Mobilitas Plus Top Researcher grant “MOBTT24.” UG was supported by the BMBF project “Hydrodynamic observations and simulations of munition in the sea,” a subproject of the collaborative project “Environmental monitoring for the delaboration of munitions in the sea” (Grant No. #03F0747C)

    A behavioural intervention increases physical activity in people with subacute spinal cord injury: a randomised trial

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    AbstractQuestions: For people with subacute spinal cord injury, does rehabilitation that is reinforced with the addition of a behavioural intervention to promote physical activity lead to a more active lifestyle than rehabilitation alone? Design: Randomised, controlled trial with concealed allocation, intention-to-treat analysis, and blinded assessors. Participants: Forty-five adults with subacute spinal cord injury who were undergoing inpatient rehabilitation and were dependent on a manual wheelchair. The spinal cord injuries were characterised as: tetraplegia 33%; motor complete 62%; mean time since injury 150 days (SD 74). Intervention: All participants received regular rehabilitation, including handcycle training. Only the experimental group received a behavioural intervention promoting an active lifestyle after discharge. This intervention involved 13 individual sessions delivered by a coach who was trained in motivational interviewing; it began 2 months before and ended 6 months after discharge from inpatient rehabilitation. Outcome measures: The primary outcome was physical activity, which was objectively measured with an accelerometer-based activity monitor 2 months before discharge, at discharge, and 6 and 12 months after discharge from inpatient rehabilitation. The accelerometry data were analysed as total wheeled physical activity, sedentary time and motility. Self-reported physical activity was a secondary outcome. Results: The behavioural intervention significantly increased wheeled physical activity (overall between-group difference from generalised estimating equation 21minutes per day, 95% CI 8 to 35). This difference was evident 6 months after discharge (28minutes per day, 95% CI 8 to 48) and maintained at 12 months after discharge (25minutes per day, 95% CI 1 to 50). No significant intervention effect was found for sedentary time or motility. Self-reported physical activity also significantly improved. Conclusion: The behavioural intervention was effective in eliciting a behavioural change toward a more active lifestyle among people with subacute spinal cord injury. Trial registration: NTR2424. [Nooijen CFJ, Stam H, Bergen MP, Bongers-Janssen HMH, Valent L, van Langeveld S, Twisk J, Act-Active Research Group, van den Berg-Emons RJG (2016) A behavioural intervention increases physical activity in people with subacute spinal cord injury: a randomised trial. Journal of Physiotherapy 62: 35–41

    Climate change threatens polar bear populations : a stochastic demographic analysis

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    Author Posting. © Ecological Society of America, 2010. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 91 (2010): 2883–2897, doi:10.1890/09-1641.1.The polar bear (Ursus maritimus) depends on sea ice for feeding, breeding, and movement. Significant reductions in Arctic sea ice are forecast to continue because of climate warming. We evaluated the impacts of climate change on polar bears in the southern Beaufort Sea by means of a demographic analysis, combining deterministic, stochastic, environment-dependent matrix population models with forecasts of future sea ice conditions from IPCC general circulation models (GCMs). The matrix population models classified individuals by age and breeding status; mothers and dependent cubs were treated as units. Parameter estimates were obtained from a capture–recapture study conducted from 2001 to 2006. Candidate statistical models allowed vital rates to vary with time and as functions of a sea ice covariate. Model averaging was used to produce the vital rate estimates, and a parametric bootstrap procedure was used to quantify model selection and parameter estimation uncertainty. Deterministic models projected population growth in years with more extensive ice coverage (2001–2003) and population decline in years with less ice coverage (2004–2005). LTRE (life table response experiment) analysis showed that the reduction in λ in years with low sea ice was due primarily to reduced adult female survival, and secondarily to reduced breeding. A stochastic model with two environmental states, good and poor sea ice conditions, projected a declining stochastic growth rate, log λs, as the frequency of poor ice years increased. The observed frequency of poor ice years since 1979 would imply log λs ≈ − 0.01, which agrees with available (albeit crude) observations of population size. The stochastic model was linked to a set of 10 GCMs compiled by the IPCC; the models were chosen for their ability to reproduce historical observations of sea ice and were forced with “business as usual” (A1B) greenhouse gas emissions. The resulting stochastic population projections showed drastic declines in the polar bear population by the end of the 21st century. These projections were instrumental in the decision to list the polar bear as a threatened species under the U.S. Endangered Species Act.We acknowledge primary funding for model development and analysis from the U.S. Geological Survey and additional funding from the National Science Foundation (DEB-0343820 and DEB-0816514), NOAA, the Ocean Life Institute and the Arctic Research Initiative at WHOI, and the Institute of Arctic Biology at the University of Alaska–Fairbanks. Funding for the capture–recapture effort in 2001–2006 was provided by the U.S. Geological Survey, the Canadian Wildlife Service, the Department of Environment and Natural Resources of the Government of the Northwest Territories, and the Polar Continental Shelf Project, Ottawa, Canada

    Characterization of single gene copy number variants in schizophrenia

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    Background Genetic studies of schizophrenia have implicated numerous risk loci including several copy number variants (CNVs) of large effect and hundreds of loci of small effect. In only a few cases has a specific gene been clearly identified. Rare CNVs affecting a single gene offer a potential avenue to discovering schizophrenia risk genes. Methods CNVs were generated from exome-sequencing of 4,913 schizophrenia cases and 6,188 controls from Sweden. We integrated multiple CNV calling methods (XHMM and ExomeDepth) to expand our set of single-gene CNVs and leveraged two different approaches for validating these variants (qPCR and Nanostring). Results We found a significant excess of all rare CNVs (deletions p=0.0004, duplications p=0.0006) and single-gene CNVs (deletions p=0.04, duplications p=0.03) in schizophrenia cases compared to controls. An expanded set of CNVs generated from integrating multiple approaches showed a significant burden of deletions in 11/21 gene-sets previously implicated in schizophrenia and across all genes in those sets (p=0.008), although no tests survived correction. We performed an extensive validation of all deletions in the significant set of voltage-gated calcium channels among CNVs called from both exome-sequencing and genotyping arrays. In total, 4 exonic, single-gene deletions validated in cases and none in controls (p=0.039), of which all were identified by exome-sequencing. Conclusions These results point to the potential contribution of single-gene CNVs to schizophrenia, that the utility of exome-sequencing for CNV calling has yet to be maximized and single-gene CNVs should be included in gene focused studies using other classes of variation

    Environment And Genetics in Lung cancer Etiology (EAGLE) study: An integrative population-based case-control study of lung cancer

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    Background: Lung cancer is the leading cause of cancer mortality worldwide. Tobacco smoking is its primary cause, and yet the precise molecular alterations induced by smoking in lung tissue that lead to lung cancer and impact survival have remained obscure. A new framework of research is needed to address the challenges offered by this complex disease. Methods/Design: We designed a large population-based case-control study that combines a traditional molecular epidemiology design with a more integrative approach to investigate the dynamic process that begins with smoking initiation, proceeds through dependency/smoking persistence, continues with lung cancer development and ends with progression to disseminated disease or response to therapy and survival. The study allows the integration of data from multiple sources in the same subjects (risk factors, germline variation, genomic alterations in tumors, and clinical endpoints) to tackle the disease etiology from different angles. Before beginning the study, we conducted a phone survey and pilot investigations to identify the best approach to ensure an acceptable participation in the study from cases and controls. Between 2002 and 2005, we enrolled 2101 incident primary lung cancer cases and 2120 population controls, with 86.6% and 72.4% participation rate, respectively, from a catchment area including 216 municipalities in the Lombardy region of Italy. Lung cancer cases were enrolled in 13 hospitals and population controls were randomly sampled from the area to match the cases by age, gender and residence. Detailed epidemiological information and biospecimens were collected from each participant, and clinical data and tissue specimens from the cases. Collection of follow-up data on treatment and survival is ongoing. Discussion: EAGLE is a new population-based case-control study that explores the full spectrum of lung cancer etiology, from smoking addiction to lung cancer outcome, through examination of epidemiological, molecular, and clinical data. We have provided a detailed description of the study design, field activities, management, and opportunities for research following this integrative approach, which allows a sharper and more comprehensive vision of the complex nature of this disease. The study is poised to accelerate the emergence of new preventive and therapeutic strategies with potentially enormous impact on public health
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