530 research outputs found

    Spatial patterns of linear and nonparametric long-term trends in Baltic sea-level variability

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    The study of long-term trends in tide gauge data is important for understanding the present and future risk of changes in sea-level variability for coastal zones, particularly with respect to the ongoing debate on climate change impacts. Traditionally, most corresponding analyses have exclusively focused on trends in mean sea-level. However, such studies are not able to provide sufficient information about changes in the full probability distribution (especially in the more extreme quantiles). As an alternative, in this paper we apply quantile regression (QR) for studying changes in arbitrary quantiles of sea-level variability. For this purpose, we chose two different QR approaches and discuss the advantages and disadvantages of different settings. In particular, traditional linear QR poses very restrictive assumptions that are often not met in reality. For monthly data from 47 tide gauges from along the Baltic Sea coast, the spatial patterns of quantile trends obtained in linear and nonparametric (spline-based) frameworks display marked differences, which need to be understood in order to fully assess the impact of future changes in sea-level variability on coastal areas. In general, QR demonstrates that the general variability of Baltic sea-level has increased over the last decades. Linear quantile trends estimated for sliding windows in time reveal a wide-spread acceleration of trends in the median, but only localised changes in the rates of changes in the lower and upper quantiles

    LAITOR - Literature Assistant for Identification of Terms co-Occurrences and Relationships

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    BACKGROUND: Biological knowledge is represented in scientific literature that often describes the function of genes/proteins (bioentities) in terms of their interactions (biointeractions). Such bioentities are often related to biological concepts of interest that are specific of a determined research field. Therefore, the study of the current literature about a selected topic deposited in public databases, facilitates the generation of novel hypotheses associating a set of bioentities to a common context. RESULTS: We created a text mining system (LAITOR: Literature Assistant for Identification of Terms co-Occurrences and Relationships) that analyses co-occurrences of bioentities, biointeractions, and other biological terms in MEDLINE abstracts. The method accounts for the position of the co-occurring terms within sentences or abstracts. The system detected abstracts mentioning protein-protein interactions in a standard test (BioCreative II IAS test data) with a precision of 0.82-0.89 and a recall of 0.48-0.70. We illustrate the application of LAITOR to the detection of plant response genes in a dataset of 1000 abstracts relevant to the topic. CONCLUSIONS: Text mining tools combining the extraction of interacting bioentities and biological concepts with network displays can be helpful in developing reasonable hypotheses in different scientific backgrounds

    Induction of a gloverin-like antimicrobial polypeptide in the sugarcane borer Diatraea saccharalis challenged by septic injury

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    Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) is an important pest for Brazilian sugarcane. In the present study, we detected two distinct spots in hemolymph from septic injured larvae (HDs1 and HDs2), which are separated by 2DE gel electrophoresis. Both spots were subjected to in-gel tryptic digestion and MALDI-TOF/TOF analysis, which revealed the sequence VFGTLGSDDSGLFGK present in both HDs1 and HDs2. This sequence had homology and 80% identity with specific Lepidoptera antimicrobial peptides called gloverins. Analyses using the ImageMaster 2D software showed pI 8.94 of the HDs1 spot, which is similar to that described to Hyalophora gloveri gloverin (pI 8.5). Moreover, the 14-kDa molecular mass of the spot HDs1 is compatible to that of gloverins isolated from the hemolymph of Trichoplusia ni, Helicoverpa armigera and H. gloveri. Antimicrobial assays with partially purified fractions containing the HDs1 and HDs2 polypeptides demonstrated activity against Escherichia coli. This is the first report of antimicrobial polypeptides in D. saccharalis, and the identification of these peptides may help in the generation of new strategies to control this pest

    The current and future burden of hepatitis B in Switzerland: a modelling study.

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    Chronic hepatitis B infection (defined as sustained detection of hepatitis B virus [HBV] surface antigen [HBsAg] protein in serum) is a leading cause of cirrhosis, hepatocellular carcinoma and liver-related deaths. A situation analysis carried out by the Swiss Federal Office of Public Health estimated the HBsAg prevalence in Switzerland to be 0.53% (95% CI: 0.32-0.89%) in 2015 (~44,000 cases). A lower prevalence of chronic HBV in the younger generation and the adoption of universal coverage in the first year of life are expected to decrease the burden of HBV; however, a number of people in key populations (including migrants) remain undiagnosed and untreated, and infected individuals remain at risk of progressing to cirrhosis, hepatocellular carcinoma and death. Our primary objective was to examine the current and estimate the future disease burden of HBV in Switzerland and the impact of migration. The secondary objective was to estimate the impact of changing future treatment numbers. A modelling study was performed using an existing, validated model (PRoGReSs Model) applied to the Swiss context. Model inputs were selected through a literature search and expert consensus. Population data from the Federal Statistical Office were used alongside prevalence data from the Polaris Observatory to estimate the number of HBV infections among people born abroad. The PRoGReSs Model was populated with and calibrated to the available data and what-if scenarios were developed to explore the impact of intervention on the future burden of disease. A Monte Carlo simulation was used to estimate 95% uncertainty intervals (95% UIs). In 2020, there were an estimated 50,100 (95% UI: 47,500-55,000) HBsAg+ cases among people born abroad. Among people born in Switzerland, there were approximately 62,700 (UI: 58,900-68,400) total HBV infections (0.72% [UI: 0.68-0.79%] prevalence). Prevalence among infants and children under the age of 5 were both <0.1%. By 2030, prevalence of HBV is expected to decrease, although morbidity and mortality will increase. Increasing diagnosis (90%) and treatment (80% of those eligible) to meet the global health sector strategy on viral hepatitis programme targets could prevent 120 cases of hepatocellular carcinoma and 120 liver-related deaths. Thanks to the historical vaccination programmes and the continued rollout of universal 3-dose coverage in the first year of life, Switzerland is expected to exceed the global health sector strategy targets for the reduction of incidence. While overall prevalence is decreasing, the current diagnosis and treatment levels remain below global health sector strategy targets

    Entangled-Photon Generation from Parametric Down-Conversion in Media with Inhomogeneous Nonlinearity

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    We develop and experimentally verify a theory of Type-II spontaneous parametric down-conversion (SPDC) in media with inhomogeneous distributions of second-order nonlinearity. As a special case, we explore interference effects from SPDC generated in a cascade of two bulk crystals separated by an air gap. The polarization quantum-interference pattern is found to vary strongly with the spacing between the two crystals. This is found to be a cooperative effect due to two mechanisms: the chromatic dispersion of the medium separating the crystals and spatiotemporal effects which arise from the inclusion of transverse wave vectors. These effects provide two concomitant avenues for controlling the quantum state generated in SPDC. We expect these results to be of interest for the development of quantum technologies and the generation of SPDC in periodically varying nonlinear materials.Comment: submitted to Physical Review
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