3,160 research outputs found

    Scaling and trends of hourly precipitation extremes in two different climate zones – Hong Kong and the Netherlands

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    Hourly precipitation extremes in very long time series from the Hong Kong Observatory and the Netherlands are investigated. Using the 2 m dew point temperature from 4 h before the rainfall event as a measure of near surface absolute humidity, hourly precipitation extremes closely follow a 14% per degree dependency – a scaling twice as large as following from the Clausius-Clapeyron relation. However, for dew point temperatures above 23 °C no significant dependency on humidity was found. Strikingly, in spite of the large difference in climate, results are almost identical in Hong Kong and the Netherlands for the dew point temperature range where both observational sets have sufficient data. Trends in hourly precipitation extremes show substantial increases over the last century for both De Bilt (the Netherlands) and Hong Kong. For De Bilt, not only the long term trend, but also variations in hourly precipitation extremes on an inter-decadal timescale of 30 yr and longer, can be linked very well to the above scaling; there is a very close resemblance between variations in dew point temperature and precipitation intensity with an inferred dependency of hourly precipitation extremes of 10 to 14% per degree. For Hong Kong there is no connection between variations in humidity and those in precipitation intensity in the wet season, May to September. This is consistent with the found zero-dependency of precipitation intensity on humidity for dew points above 23 °C. Yet, outside the wet season humidity changes do appear to explain the positive trend in hourly precipitation extremes, again following a dependency close to twice the Clausius-Clapeyron relation

    A targeted gene panel that covers coding, non-coding and short tandem repeat regions improves the diagnosis of patients with neurodegenerative diseases

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    Genetic testing for neurodegenerative diseases (NDs) is highly challenging because of genetic heterogeneity and overlapping manifestations. Targeted-gene panels (TGPs), coupled with next-generation sequencing (NGS), can facilitate the profiling of a large repertoire of ND-related genes. Due to the technical limitations inherent in NGS and TGPs, short tandem repeat (STR) variations are often ignored. However, STR expansions are known to cause such NDs as Huntington\u27s disease and spinocerebellar ataxias type 3 (SCA3). Here, we studied the clinical utility of a custom-made TGP that targets 199 NDs and 311 ND-associated genes on 118 undiagnosed patients. At least one known or likely pathogenic variation was found in 54 patients; 27 patients demonstrated clinical profiles that matched the variants; and 16 patients whose original diagnosis were refined. A high concordance of variant calling were observed when comparing the results from TGP and whole-exome sequencing of four patients. Our in-house STR detection algorithm has reached a specificity of 0.88 and a sensitivity of 0.82 in our SCA3 cohort. This study also uncovered a trove of novel and recurrent variants that may enrich the repertoire of ND-related genetic markers. We propose that a combined comprehensive TGPs-bioinformatics pipeline can improve the clinical diagnosis of NDs

    Development of Shear Modulus Reduction Curves Based on Lotung Downhole Ground Motion Data

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    In this study, equivalent shear moduli (or shear-wave velocities) and their variations with shearing strain at the Lotung seismic experiment site were back-calculated from recorded downhole array ground motions. Ground motion data for various levels of shaking (peak ground surface accelerations ranging from 0.03g to 0.21g) recorded during seven earthquakes were used in the analyses. Results show that downhole array ground motion data can be used to infer in-situ dynamic soil properties over a wide strain range

    Astrogliopathy predominates the earliest stage of corticobasal degeneration pathology.

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    Animal models have shown that tau seeding and propagation are strain- and neural network-specific. The study of preclinical cases is valuable to gain insights into early pathological features of corticobasal degeneration and its progression. Three preclinical corticobasal degeneration cases and six age-matched end-stage corticobasal degeneration cases were included in this study. Tau immunohistochemistry performed in 20 brain regions and quantitative assessment of regional tau load using image analysis were performed. Semi-quantitative grading of tau-positive cellular lesions and neuronal loss in the frontal, parietal and temporal cortices, striatum, substantia nigra and subthalamic nucleus were assessed. All preclinical cases were clinically asymptomatic but had widespread tau lesions in the typically affected regions in corticobasal degeneration and the pathognomonic astrocytic plaques were the most prominent lesion type in the anterior frontal and striatal regions. Mean total tau load (sum of all regional tau load) of end-stage corticobasal degeneration cases were nine times greater than that of the preclinical cases (P = 0.04) and less tau load was found in all regions of the preclinical cases. An anterior-to-posterior tau load ratio in the frontal cortex in preclinical cases was 12-fold greater than in end-stage corticobasal degeneration cases. Relatively greater tau burden in the anterior frontal cortex, striatum and subthalamic nucleus suggests the striatal afferent connection to the dorsolateral prefrontal cortex and basal ganglia circuitry are the earliest neural network connections affected by corticobasal degeneration-related tau pathology. Differential distribution of the tau pathology to selective cortical regions in these preclinical cases implies phenotypic presentation may be predetermined at a very early stage of the disease process. Neuronal loss of the substantia nigra was either absent or very mild in the preclinical cases and was moderate to severe in end-stage corticobasal degeneration cases (P < 0.05). Our findings suggest that a threshold of pathological burden in the ‘right’ anatomical regions needs to be reached before the onset of clinical symptoms. The early prominence of the astrocytic plaques in relation to sparse neuronal lesions leads one to speculate that corticobasal degeneration may begin as an astrogliopathy at a very early disease stage but neuronal lesions gradually take over as the predominant lesion type in advanced disease

    Non-ancient solution of the Ricci flow

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    For any complete noncompact Ka¨\ddot{a}hler manifold with nonnegative and bounded holomorphic bisectional curvature,we provide the necessary and sufficient condition for non-ancient solution to the Ricci flow in this paper.Comment: seven pages, latex fil

    Sio: A spatioimageomics pipeline to identify prognostic biomarkers associated with the ovarian tumor microenvironment

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    Stromal and immune cells in the tumor microenvironment (TME) have been shown to directly affect high-grade serous ovarian cancer (HGSC) malignant phenotypes, however, how these cells interact to influence HGSC patients’ survival remains largely unknown. To investigate the cell-cell communication in such a complex TME, we developed a SpatioImageOmics (SIO) pipeline that combines imaging mass cytometry (IMC), location-specific transcriptomics, and deep learning to identify the distribution of various stromal, tumor and immune cells as well as their spatial relationship in TME. The SIO pipeline automatically and accurately segments cells and extracts salient cellular features to identify biomarkers, and multiple nearest-neighbor interactions among tumor, immune, and stromal cells that coordinate to influence overall survival rates in HGSC patients. In addition, SIO integrates IMC data with microdissected tumor and stromal transcriptomes from the same patients to identify novel signaling networks, which would lead to the discovery of novel survival rate-modulating mechanisms in HGSC patients

    Emerging invasive group A Streptococcus M1UK lineage detected by allele-specific PCR, England, 2020

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    Increasing reports of invasive Streptococcus pyogenes infections mandate surveillance for toxigenic lineage M1UK. An allele-specific PCR was developed to distinguish M1UK from other emm1 strains. The M1UK lineage represented 91% of invasive emm1 isolates in England in 2020. Allele-specific PCR will permit surveillance for M1UK without need for genome sequencing

    Equidistribution of zeros of holomorphic sections in the non compact setting

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    We consider N-tensor powers of a positive Hermitian line bundle L over a non-compact complex manifold X. In the compact case, B. Shiffman and S. Zelditch proved that the zeros of random sections become asymptotically uniformly distributed with respect to the natural measure coming from the curvature of L, as N tends to infinity. Under certain boundedness assumptions on the curvature of the canonical line bundle of X and on the Chern form of L we prove a non-compact version of this result. We give various applications, including the limiting distribution of zeros of cusp forms with respect to the principal congruence subgroups of SL2(Z) and to the hyperbolic measure, the higher dimensional case of arithmetic quotients and the case of orthogonal polynomials with weights at infinity. We also give estimates for the speed of convergence of the currents of integration on the zero-divisors.Comment: 25 pages; v.2 is a final update to agree with the published pape
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