3,276 research outputs found
The role of atrial natriuretic peptide to attenuate inflammation in a mouse skin wound and individually perfused rat mesenteric microvessels.
We tested the hypothesis that the anti-inflammatory actions of atrial natriuretic peptide (ANP) result from the modulation of leukocyte adhesion to inflamed endothelium and not solely ANP ligation of endothelial receptors to stabilize endothelial barrier function. We measured vascular permeability to albumin and accumulation of fluorescent neutrophils in a full-thickness skin wound on the flank of LysM-EGFP mice 24Â h after formation. Vascular permeability in individually perfused rat mesenteric microvessels was also measured after leukocytes were washed out of the vessel lumen. Thrombin increased albumin permeability and increased the accumulation of neutrophils. The thrombin-induced inflammatory responses were attenuated by pretreating the wound with ANP (30Â min). During pretreatment ANP did not lower permeability, but transiently increased baseline albumin permeability concomitant with the reduction in neutrophil accumulation. ANP did not attenuate acute increases in permeability to histamine and bradykinin in individually perfused rat microvessels. The hypothesis that anti-inflammatory actions of ANP depend solely on endothelial responses that stabilize the endothelial barrier is not supported by our results in either individually perfused microvessels in the absence of circulating leukocytes or the more chronic skin wound model. Our results conform to the alternate hypothesis that ANP modulates the interaction of leukocytes with the inflamed microvascular wall of the 24Â h wound. Taken together with our previous observations that ANP reduces deformability of neutrophils and their strength of attachment, rolling, and transvascular migration, these observations provide the basis for additional investigations of ANP as an anti-inflammatory agent to modulate leukocyte-endothelial cell interactions
Characterizing temporary hydrological regimes at a European scale
Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios
Privacy-Preserving Tensor Factorization for Collaborative Health Data Analysis
Tensor factorization has been demonstrated as an efficient approach for
computational phenotyping, where massive electronic health records (EHRs) are
converted to concise and meaningful clinical concepts. While distributing the
tensor factorization tasks to local sites can avoid direct data sharing, it
still requires the exchange of intermediary results which could reveal
sensitive patient information. Therefore, the challenge is how to jointly
decompose the tensor under rigorous and principled privacy constraints, while
still support the model's interpretability. We propose DPFact, a
privacy-preserving collaborative tensor factorization method for computational
phenotyping using EHR. It embeds advanced privacy-preserving mechanisms with
collaborative learning. Hospitals can keep their EHR database private but also
collaboratively learn meaningful clinical concepts by sharing differentially
private intermediary results. Moreover, DPFact solves the heterogeneous patient
population using a structured sparsity term. In our framework, each hospital
decomposes its local tensors, and sends the updated intermediary results with
output perturbation every several iterations to a semi-trusted server which
generates the phenotypes. The evaluation on both real-world and synthetic
datasets demonstrated that under strict privacy constraints, our method is more
accurate and communication-efficient than state-of-the-art baseline methods
Development of a high-density CHO-C system enables rapid protein production in 10 days
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Tissue inhibitor of metalloproteinase-1 (TIMP-1) regulates mesenchymal stem cells through let-7f microRNA and Wnt/β-catenin signaling
Tissue inhibitor of metalloproteinases 1 (TIMP-1) is a matrix metalloproteinase (MMP)-independent regulator of growth and apoptosis in various cell types. The receptors and signaling pathways that are involved in the growth factor activities of TIMP-1, however, remain controversial. RNA interference of TIMP-1 has revealed that endogenous TIMP-1 suppresses the proliferation, metabolic activity, and osteogenic differentiation capacity of human mesenchymal stem cells (hMSCs). The knockdown of TIMP-1 in hMSCs activated the Wnt/β-catenin signaling pathway as indicated by the increased stability and nuclear localization of β-catenin in TIMP-1–deficient hMSCs. Moreover, TIMP-1 knockdown cells exhibited enhanced β-catenin transcriptional activity, determined by Wnt/β-catenin target gene expression analysis and a luciferase-based β-catenin–
activated reporter assay. An analysis of a mutant form of TIMP-1 that cannot inhibit MMP indicated that the effect of TIMP-1 on β-catenin signaling is MMP independent. Furthermore, the binding of CD63 to TIMP-1 on the surface of hMSCs is essential for the TIMP-1–mediated effects on Wnt/β-catenin signaling. An array analysis of microRNAs (miRNAs) and transfection studies with specific miRNA inhibitors and mimics showed that let-7f miRNA is crucial for the regulation of β-catenin activity and osteogenic differentiation by TIMP-1. Let-7f was up-regulated in TIMP-1–depleted hMSCs and demonstrably reduced axin 2, an antagonist of β-catenin stability. Our results demonstrate that TIMP-1 is a direct regulator of hMSC functions and reveal a regulatory network in which let-7f modulates Wnt/β-catenin activity
How is Vaping Framed on Online Knowledge Dissemination Platforms?
We analyze 1,888 articles and 1,119,453 vaping posts to study how vaping is
framed across multiple knowledge dissemination platforms (Wikipedia, Quora,
Medium, Reddit, Stack Exchange, wikiHow). We use various NLP techniques to
understand these differences. For example, n-grams, emotion recognition, and
question answering results indicate that Medium, Quora, and Stack Exchange are
appropriate venues for those looking to transition from smoking to vaping.
Other platforms (Reddit, wikiHow) are more for vaping hobbyists and may not
sufficiently dissuade youth vaping. Conversely, Wikipedia may exaggerate vaping
harms, dissuading smokers from transitioning. A strength of our work is how the
different techniques we have applied validate each other. Based on our results,
we provide several recommendations. Stakeholders may utilize our findings to
design informational tools to reinforce or mitigate vaping (mis)perceptions
online.Comment: arXiv admin note: text overlap with arXiv:2206.07765,
arXiv:2206.0902
Growth of Pure Zinc-Blende GaAs(P) Core-Shell Nanowires with Highly Regular Morphology
The growth of self-catalyzed core–shell nanowires (NWs) is investigated systematically using GaAs(P) NWs. The defects in the core NW are found to be detrimental for the shell growth. These defects are effectively eliminated by introducing beryllium (Be) doping during the NW core growth and hence forming Be–Ga alloy droplets that can effectively suppress the WZ nucleation and facilitate the droplet consumption. Shells with pure zinc-blende crystal quality and highly regular morphology are successfully grown on the defect-free NW cores and demonstrated an enhancement of one order of magnitude for room-temperature emission compared to that of the defective shells. These results provide useful information on guiding the growth of high-quality shell, which can greatly enhance the NW device performance
Self-assembly of quantum dots: effect of neighbor islands on the wetting in coherent Stranski-Krastanov growth
The wetting of the homogeneously strained wetting layer by dislocation-free
three-dimensional islands belonging to an array has been studied. The array has
been simulated as a chain of islands in 1+1 dimensions. It is found that the
wetting depends on the density of the array, the size distribution and the
shape of the neighbor islands. Implications for the self-assembly of quantum
dots grown in the coherent Stranski-Krastanov mode are discussed.Comment: 4 pages, 6 figures, accepted version, minor change
UK agriculture and care visas: worker exploitation and obstacles to redress
This is a summary of research conducted by five academics (led by Primary Investigator Dr Inga Thiemann) in partnership with four non-governmental organisations (NGOs): Focus on Labour Exploitation (FLEX), Joint Council for the Welfare of Immigrants (JCWI), Southeast and East Asian Centre (SEEAC) and Kanlungan Filipino Consortium (Kanlungan), with support from UNISON. The project was funded through an open call for proposals by the Modern Slavery and Human Rights Policy and Evidence Centre (Modern Slavery PEC), which in turn is funded and supported by the UK Arts and Humanities Research Council (AHRC). The Modern Slavery PEC has actively supported the production of this Research Summary. However, the views expressed in this summary and the full report are those of the authors and not necessarily of the funders
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