We studied the long-term (20-year) cumulative effects of exclusion of livestock grazing on above- and belowground community properties compared with that before exclusion of livestock grazing in a ...typical steppe of the Loess Plateau, NW China. Our results show that twenty-year exclusion of livestock grazing significantly increased above- and belowground biomass, species richness, cover and height for five different communities. Most of belowground biomass was in the 0-20 cm horizon and grazing exclusion increased biomass especially at the depth of 0-10 cm. Our study suggests that long-term exclusion of livestock grazing can greatly improve community properties of typical steppe in the Loess Plateau.
Vascular endothelial growth factor (VEGF) exerts many of its effects by stimulating endothelial calcium influx, but little is known about channels mediating VEGF-induced cation entry. The aim of this ...study was to measure and characterize for the first time the VEGF-activated cation current in human microvascular endothelial cells (HMVECs).
Whole-cell patch-clamp recordings were made from HMVECs. During applied voltage ramps, VEGF activated a current that reversed at 0 mV, was sensitive to gadolinium, and required extracellular cations. Noise analysis yielded a single-channel conductance of 27 pS. The current was not dependent on intracellular calcium stores, and was not blocked by inositol triphosphate (IP3) receptor or serine/threonine kinase inhibition but was partially inhibited by flufenamic acid. A similar current was activated by 1-oleoyl-2-acetyl-sn-glycerol (OAG), a membrane-permeant analog of diacylglycerol (DAG). To determine whether VEGF could activate recombinant ion channels with similar properties, we investigated the effect of VEGF on Chinese hamster ovary cells cotransfected with VEGFR2 and the canonical transient receptor potential (TRPC) channels, TRPC3 or TRPC6. VEGF induced a similar current to that described above in VEGFR2-TRPC3 and VEGFR2-TRPC6 cells but not in cells transfected with either cDNA alone.
VEGF activates a receptor-operated cation current in HMVECs and OAG can activate directly a similar current in these cells. VEGF is also able to activate heterologously expressed TRPC3/6 channels through VEGFR2.
Experimental manipulation of protein abundance in living cells or organisms is an essential strategy for investigation of biological regulatory mechanisms. Whereas powerful techniques for protein ...expression have been developed in Caenorhabditis elegans, existing tools for conditional disruption of protein function are far more limited. To address this, we have adapted the auxin-inducible degradation (AID) system discovered in plants to enable conditional protein depletion in C. elegans. We report that expression of a modified Arabidopsis TIR1 F-box protein mediates robust auxin-dependent depletion of degron-tagged targets. We document the effectiveness of this system for depletion of nuclear and cytoplasmic proteins in diverse somatic and germline tissues throughout development. Target proteins were depleted in as little as 20-30 min, and their expression could be re-established upon auxin removal. We have engineered strains expressing TIR1 under the control of various promoter and 3' UTR sequences to drive tissue-specific or temporally regulated expression. The degron tag can be efficiently introduced by CRISPR/Cas9-based genome editing. We have harnessed this system to explore the roles of dynamically expressed nuclear hormone receptors in molting, and to analyze meiosis-specific roles for proteins required for germ line proliferation. Together, our results demonstrate that the AID system provides a powerful new tool for spatiotemporal regulation and analysis of protein function in a metazoan model organism.
Context:
Available data related to the metabolically healthy obesity (MHO) phenotype are mainly derived from studies in adults because studies during childhood are very limited to date.
Objective:
...The objective of the study was to determine the prevalence of MHO in Chinese children and to investigate environmental and genetic factors impacting on MHO status.
Design:
This was a cross-sectional study.
Participants:
A total of 1213 children with a body mass index at the 95th percentile or greater aged 6–18 years were included in this study. Participants were classified as MHO or of metabolically unhealthy obesity based on insulin resistance (IR) or cardiometabolic risk (CR) factors (blood pressure, lipids, and glucose). Twenty-two genetic variants previously reported from genome-wide association studies of obesity and diabetes plus the environmental factors of lifestyle, socioeconomic status, and birth weight was assessed.
Results:
The prevalence of MHO-IR and MHO-CR were 27.1% and 37.2%, respectively. Waist circumference was an independent predictor of MHO, regardless of definitions, whereas walking to school and KCNQ1-rs2237897 were independent predictors of MHO-CR. Acanthosis nigricans, birth weight, the frequency of soft drink consumption, the mother's education status, and KCNQ1-rs2237892 were independent predictors of MHO-IR. Multiplicative interaction effects were found between KCNQ1-rs2237897 and walking to school on MHO-CR (odds ratio 1.31 95% confidence interval 1.05–1.63) and between rs2237892 and consumption of soft drinks on MHO-IR (odds ratio 0.80 95% confidence interval 0.68–0.94).
Conclusions:
Approximately one-third of Chinese obese children can be classified as MHO. Both genetic predisposition and environment factors and their interaction contribute to the prediction of MHO status. This study provides novel insights into the heterogeneity of obesity and has the potential to impact the optimization of the intervention options and regimens in the management of pediatric obesity.
This study provides novel insights into the heterogeneity of obesity, and has the potential to impact the optimization of the intervention options and regimes in the management of pediatric obesity.
Highlights • EEG oscillatory power was correlated with ratings of the conditioning stimuli (CS) in a fear conditioning protocol. • Only the delta/theta (0-8 Hz) Time Frequency Windows showed an ...effect of CS on power. • The Expectancy rating was the likelihood that the CS predicted the painful laser unconditioned stimulus. • Expectancy was related to power less often than CS Valence (unpleasantness) or Salience (ability to capture attention). • EEG was related to Valence and Salience more than Expectancy to produce the unpleasant attentional aspect of a threat.
COVID-19 emerged at varying intervals in different regions of the United States in 2020. This report details the epidemiologic and genetic evolution of Severe acute respiratory syndrome coronavirus 2 ...(SARS-CoV-2) during the first year of the epidemic in the state of Nebraska using data collected from the Creighton Catholic Health Initiatives (CHI) health system. Statistical modelling identified age, gender, and previous history of diabetes and/or stroke as significant risk factors associated with mortality in COVID-19 patients. In parallel, the viral genomes of over 1,000 samples were sequenced. The overall rate of viral variation in the population was 0.07 mutations/day. Genetically, the first 9 months of the outbreak, which include the initial outbreak, a small surge in August and a major outbreak in November 2020 were primarily characterized by B.1. lineage viruses. In early 2021, the United Kingdom variant (B.1.1.7 or alpha) quickly became the dominant variant. Notably, surveillance of non-consensus variants detected B.1.1.7 defining mutations months earlier in Fall 2020. This work provides insights into the regional variance and evolution of SARS-CoV-2 in the Nebraska region during the first year of the pandemic.
Jupiter's moon lo is known to host active volcanoes. In February and March 2007, the New Horizons spacecraft obtained a global snapshot of lo's volcanism. A 350-kilometer-high volcanic plume was seen ...to emanate from the Tvashtar volcano (62°N, 122°W), and its motion was observed. The plume's morphology and dynamics support nonballistic models of large lo plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source. In images taken in Jupiter eclipse, nonthermal visible-wavelength emission was seen from individual volcanoes near lo's sub-Jupiter and anti-Jupiter points. Near-infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150- to 1335-kelvin range, consistent with basaltic composition.
•A capillary bundle model is used to predict the permeability and streaming potential of a porous transducer.•The bulk porosity and the particle size distribution of the transducer are used to ...specify the model structure.•A model of zeta potential and a method to relate the particle size to the capillary radius are applied.•The proposed model shows good accuracy and can be used to optimize the transducer design.
A capillary bundle model is used to evaluate the permeability and streaming potential coupling coefficient of a porous transducer, which is the key element of a fluid-based angular accelerometer. The capillary bundle is specified with structural parameters and a method to transform the particle size distribution into the capillary radius distribution. Together with a theoretical model of zeta potential and specific surface conductance, the model is applied to determine permeability and streaming potential prediction. Three types of transducers are fabricated and experiments validate the proposed model, which is an important part of the sensor model for engineering application.
ABSTRACT
We present in this paper one of the largest galaxy morphological classification catalogues to date, including over 20 million galaxies, using the Dark Energy Survey (DES) Year 3 data based ...on convolutional neural networks (CNNs). Monochromatic i-band DES images with linear, logarithmic, and gradient scales, matched with debiased visual classifications from the Galaxy Zoo 1 (GZ1) catalogue, are used to train our CNN models. With a training set including bright galaxies (16 ≤ i < 18) at low redshift (z < 0.25), we furthermore investigate the limit of the accuracy of our predictions applied to galaxies at fainter magnitude and at higher redshifts. Our final catalogue covers magnitudes 16 ≤ i < 21, and redshifts z < 1.0, and provides predicted probabilities to two galaxy types – ellipticals and spirals (disc galaxies). Our CNN classifications reveal an accuracy of over 99 per cent for bright galaxies when comparing with the GZ1 classifications (i < 18). For fainter galaxies, the visual classification carried out by three of the co-authors shows that the CNN classifier correctly categorizes discy galaxies with rounder and blurred features, which humans often incorrectly visually classify as ellipticals. As a part of the validation, we carry out one of the largest examinations of non-parametric methods, including ∼100 ,000 galaxies with the same coverage of magnitude and redshift as the training set from our catalogue. We find that the Gini coefficient is the best single parameter discriminator between ellipticals and spirals for this data set.
Almost 1-2% of the human genome is located within 500 bp of either side of a transcription initiation site, whereas a far larger proportion (≈25%) is potentially transcribable by elongating RNA ...polymerases. This observation raises the question of how the genome is packaged into chromatin to allow start sites to be recognized by the regulatory machinery at the same time as transcription initiation, but not elongation, is blocked in the 25% of intragenic DNA. We developed a chromatin scanning technique called ChAP, coupling the chromatin immunoprecipitation assay with arbitrarily primed PCR, which allows for the rapid and unbiased comparison of histone modification patterns within the eukaryotic nucleus. Methylated lysine 4 (K4) and acetylated K9/14 of histone H3 were both highly localized to the 5′ regions of transcriptionally active human genes but were greatly decreased downstream of the start sites. Our results suggest that the large transcribed regions of human genes are maintained in a deacetylated conformation in regions read by elongating polymerase. Common models depicting widespread histone acetylation and K4 methylation throughout the transcribed unit do not therefore apply to the majority of human genes.
PDF
