1,643 research outputs found

    Whole-Genome Sequence of a European Clone II and OXA-72-Producing Acinetobacter baumannii Strain from Serbia.

    Get PDF
    We report here the draft genome sequence of a carbapenem-resistant Acinetobacter baumannii strain isolated from a patient, a strain which previously stayed in Serbia. This isolate possessed the blaOXA-72 carbapenemase gene. The draft genome sequence consists of a total length of 3.91 Mbp, with an average G+C content of 38.8%

    Developing Intensity-Duration-Frequency (IDF) Curves From Satellite-Based Precipitation: Methodology and Evaluation

    Get PDF
    Given the continuous advancement in the retrieval of precipitation from satellites, it is important to develop methods that incorporate satellite-based precipitation data sets in the design and planning of infrastructure. This is because in many regions around the world, in situ rainfall observations are sparse and have insufficient record length. A handful of studies examined the use of satellite-based precipitation to develop intensity-duration-frequency (IDF) curves; however, they have mostly focused on small spatial domains and relied on combining satellite-based with ground-based precipitation data sets. In this study, we explore this issue by providing a methodological framework with the potential to be applied in ungauged regions. This framework is based on accounting for the characteristics of satellite-based precipitation products, namely, adjustment of bias and transformation of areal to point rainfall. The latter method is based on previous studies on the reverse transformation (point to areal) commonly used to obtain catchment-scale IDF curves. The paper proceeds by applying this framework to develop IDF curves over the contiguous United States (CONUS); the data set used is Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks – Climate Data Record (PERSIANN-CDR). IDFs are then evaluated against National Oceanic and Atmospheric Administration (NOAA) Atlas 14 to provide a quantitative estimate of their accuracy. Results show that median errors are in the range of (17–22%), (6–12%), and (3–8%) for one-day, two-day and three-day IDFs, respectively, and return periods in the range (2–100) years. Furthermore, a considerable percentage of satellite-based IDFs lie within the confidence interval of NOAA Atlas 14

    Evaluation of the environmental impacts of suckler calf-to-beef mixedcrop-livestock farms in northern Italy: A farm-based study

    Get PDF
    The issue of the environmental impacts of beef production has been extensively debated in recent years. However, the research on this theme has mainly been based on farm-model studies with limited attention to contribution analysis of impact categories and aspects linked to cropping systems and feed self-sufficiency in mixed crop-livestock farms. This study evaluated the cradle-tofarm gate environmental impacts of mixed-crop livestock farms rearing the Piedmontese beef breed and suckler calf-to-beef operations in Northwest Italy. Data have been collected from detailed on-farm questionnaires, field books, and invoices of 11 farms over two years (2017-2018). The environmental impacts have been evaluated in terms of land occupation (LO, m2/year), global warming potential (GWP, kg CO2-eq), acidification potential (AP, g SO2-eq) and non-renewable cumulative energy demand (CED, MJ), using life cycle assessment methodology. The functional unit considered was one kilogram of live weight produced at the farm gate. The Piedmontese beef production system showed comparable average environmental impacts with those found in other studies, even though high variability was observed in the studied farms. The GWP averaged 15.7 kg of CO2 eq/kg LW and ranged from 12.1 to 17.6 kg of CO2 eq/kg LW. The CED, LO and AP were on average 62.4 MJ/kg LW, 18.5 m2/y/kg LW and 305 g SO2 eq/kg LW, respectively. Differences in environmental impacts and GWP contribution analysis were mainly due to differences in cropping system management strategies and the consequent levels of feed self-sufficiency. A positive effect of high fertility and animal productivity was observed on the GWP (r=0.62; P<0.01), highlighting the importance of improving efficiency of these aspects for the reduction of emissions. From the contribution analysis of impact categories, the high cost of purchased feeds (in particular protein feeds), transport, and mineral fertilizers for feed production were highly relevant. However further research is needed to confirm these findings. Highlights - Study of 11 farms for two years. - High relevance of purchased feeds on environmental impacts. - Productive and reproductive performances are key points in reducing environmental impacts. - Importance of the valorisation of farm crop surfaces to satisfy animals' needs

    Porosity measurements of interstellar ice mixtures using optical laser interference and extended effective medium approximations

    Get PDF
    Aims. This article aims to provide an alternative method of measuring the porosity of multi-phase composite ices from their refractive indices and of characterising how the abundance of a premixed contaminant (e.g., CO2) affects the porosity of water-rich ice mixtures during omni-directional deposition. Methods. We combine optical laser interference and extended effective medium approximations (EMAs) to measure the porosity of three astrophysically relevant ice mixtures: H2O:CO2=10:1, 4:1, and 2:1. Infrared spectroscopy is used as a benchmarking test of this new laboratory-based method. Results. By independently monitoring the O-H dangling modes of the different water-rich ice mixtures, we confirm the porosities predicted by the extended EMAs. We also demonstrate that CO2 premixed with water in the gas phase does not significantly affect the ice morphology during omni-directional deposition, as long as the physical conditions favourable to segregation are not reached. We propose a mechanism in which CO2 molecules diffuse on the surface of the growing ice sample prior to being incorporated into the bulk and then fill the pores partly or completely, depending on the relative abundance and the growth temperature.Comment: 9 pages, 6 figures, 1 table. Accepted for publication in A&

    On the role of finite grid extent in SOLPS-ITER edge plasma simulations for JET H-mode discharges with metallic wall

    Get PDF
    The impact of the finite grid size in SOLPS-ITER edge plasma simulations is assessed for JET H-mode discharges with a metal wall. For a semi-horizontal divertor configuration it is shown that the separatrix density is at least 30% higher when a narrow scrape-off layer (SOL) grid width is chosen in SOLPS-ITER compared to the case for which the SOL grid width is maximised. The density increase is caused by kinetic neutrals being not confined inside the divertor region because of the reduced extent of the plasma grid. In this case, an enhanced level of reflections of energetic neutrals at the low-field side (LFS) metal divertor wall is observed. This leads to a shift of the ionisation source further upstream which must be accounted for as a numerical artefact. An overestimate in the cooling at the divertor entrance is observed in this case, identified by a reduced heat flux decay parameters lambda(div)(q). Otherwise and further upstream the mid-plane heat decay length lambda(q) parameter is not affected by any change in divertor dissipation. This confirms the assumptions made for the ITER divertor design studies, i.e. that lambda(q) upstream is essentially set by the assumptions for the ratio radial to parallel heat conductivity. It is also shown that even for attached conditions the decay length relations lambda(ne)>lambda(Te)>lambda(q) hold in the near-SOL upstream. Thus for interpretative edge plasma simulations one must take the (experimental) value of lambda(ne) into account, rather than lambda(q), as the former actually defines the required minimum upstream SOL grid extent.EURATOM 63305

    PLA scaffolds production from Thermally Induced Phase Separation: effect of process parameters and development of an environmentally improved route assisted by supercritical carbon dioxide

    Get PDF
    In this work, a relatively large scale of PLA scaffolds was produced using thermally induced phase separation (TIPS) combined with a supercritical carbon dioxide (SC-CO2) drying step as a green alternative. For the TIPS step, the phase separation of PLA and 1,4-dioxane solvent was controlled by adjusting the process conditions such as the polymer concentration and molecular weight, the 1,4-dioxane solvent power and the cooling conditions. The scaffolds morphology was analyzed by scanning electron microscopy. Their structural and mechanical properties were correlated together with the possibility to tune them by controlling the process conditions. An environmental analysis using the Life Cycle Assessment (LCA) methodology confirmed a reduction of at least 50% of the environmental impact of the whole process using the SC-CO2 drying compared to the traditional freeze-drying technology. This work is the first known attempt to conduct the LCA methodology on TIPS process for the PLA scaffolds production

    Assessment of Chimpanzee Nests Detectability on Drone-Acquired Images

    Get PDF
    As with other species of great apes, chimpanzee numbers have declined during the past decades. Proper conservation of the remaining chimpanzees requires accurate and frequent data on their distribution and density. In Tanzania, 75% of the chimpanzees live at low densities on land outside national parks and little is known about their distribution, density, behavior or ecology. Given the sheer scale of chimpanzee distribution across western Tanzania (>20,000 km2), we need new methods that are time and cost efficient while providing precise and accurate data across broad spatial scales. Scientists have recently demonstrated the usefulness of drones to detect wildlife, including apes. Whilst direct observation of chimpanzees is unlikely given their elusiveness, we investigated the potential of drones to detect chimpanzee nests in the Issa valley, western Tanzania. Between 2015 and 2016, we tested and compared the capabilities of two fixed-wing drones. We surveyed twenty-two plots (50x500m) in gallery forests and miombo woodlands to compare nest observations from the ground with those from the air. We performed mixed-effects logistic regression models to evaluate the impact of image resolution, seasonality, vegetation type, nest height and color on nest detectability. An average of 10% of the nests spotted from the ground were detected from the air. From the factors tested, only image resolution significantly influenced nest detectability on drone-acquired images. We discuss the potential, but also the limitations of this technology for determining chimpanzee distribution and density and provide guidance for future investigation on the use of drones for ape population surveys. Combining traditional and novel technological methods of surveying allows more accurate collection on animal distribution and habitat connectivity that has important implications for apes conservation in an increasingly anthropogenically disturbed landscape

    Holocene subsurface temperature variability in the eastern Antarctic continental margin

    Get PDF
    We reconstructed subsurface (∼45-200m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX 86 L). Our results reveal that subsurface temperature changes were probably positively coupled to the variability of warmer, nutrient-rich Modified Circumpolar Deep Water (MCDW, deep water of the Antarctic circumpolar current) intrusion onto the continental shelf. The TEX 86 L record, in combination with previously published climatic records, indicates that this coupling was probably related to the thermohaline circulation, seasonal variability in sea ice extent, sea temperature, and wind associated with high frequency climate dynamics at low-latitudes such as internal El Nio Southern Oscillation (ENSO). This in turn suggests a linkage between centennial ENSO-like variability at low-latitudes and intrusion variability of MCDW into the eastern Antarctic continental shelf, which might have further impact on ice sheet evolution. Copyright 2012 by the American Geophysical Union
    • …
    corecore