202 research outputs found

    Distributed Solvers for Network Linear Equations with Scalarized Compression

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    In this paper, we study distributed solvers for network linear equations over a network with node-to-node communication messages compressed as scalar values. Our key idea lies in a dimension compression scheme including a dimension compressing vector that applies to individual node states to generate a real-valued message for node communication as an inner product, and a data unfolding step in the local computations where the scalar message is plotted along the subspace generated by the compression vector. We first present a compressed average consensus flow that relies only on such scalar communication, and show that exponential convergence can be achieved with well excited signals for the compression vector. We then employ such a compressed consensus flow as a fundamental consensus subroutine to develop distributed continuous-time and discrete-time solvers for network linear equations, and prove their exponential convergence properties under scalar node communications. With scalar communications, a direct benefit would be the reduced node-to-node communication channel capacity requirement for distributed computing. Numerical examples are presented to illustrate the effectiveness of the established theoretical results.Comment: 8 pages, 4 figure

    Interrelation between rifting, faulting, sedimentation, and mantle serpentinization during continental margin formation-including examples from the Norwegian Sea

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    The conditions permitting mantle serpentinization during continental rifting are explored within 2-D thermotectonostratigraphic basin models, which track the rheological evolution of the continental crust, account for sediment blanketing effects, and allow for kinetically controlled mantle serpentinization processes. The basic idea is that the entire extending continental crust has to be brittle for crustal scale faulting and mantle serpentinization to occur. The isostatic and latent heat effects of the reaction are fully coupled to the structural and thermal solutions. A systematic parameter study shows that a critical stretching factor exists for which complete crustal embrittlement and serpentinization occurs. Increased sedimentation rates shift this critical stretching factor to higher values as sediment blanketing effects result in higher crustal temperatures. Sediment supply has therefore, through the temperature-dependence of the viscous flow laws, strong control on crustal strength and mantle serpentinization reactions are only likely when sedimentation rates are low and stretching factors high. In a case study for the Norwegian margin, we test whether the inner lower crustal bodies (LCB) imaged beneath the Møre and Vøring margin could be serpentinized mantle. Multiple 2-D transects have been reconstructed through the 3-D data set by Scheck-Wenderoth and Maystrenko (2011). We find that serpentinization reactions are possible and likely during the Jurassic rift phase. Predicted thicknesses and locations of partially serpentinized mantle rocks fit to information on LCBs from seismic and gravity data. We conclude that some of the inner LCBs beneath the Norwegian margin may be partially serpentinized mantle

    Three-dimensional controlled growth of monodisperse sub-50 nm heterogeneous nanocrystals

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    The ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such degree of control in a family of rare-earth-doped nanomaterials. We experimentally verify the co-existence and different roles of oleate anions (OA-) and molecules (OAH) in the crystal formation. We identify that the control over the ratio of OA- to OAH can be used to directionally inhibit, promote or etch the crystallographic facets of the nanoparticles. This control enables selective grafting of shells with complex morphologies grown over nanocrystal cores, thus allowing the fabrication of a diverse library of monodisperse sub-50 nm nanoparticles. With such programmable additive and subtractive engineering a variety of three-dimensional shapes can be implemented using a bottom-up scalable approach

    Antimicrobial Peptides in Marine Animals and Their Application in Food Preservation

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    Microbial contamination is considered an important contributor to both food spoilage and food safety issues, and the development of new natural antimicrobial agents with broad-spectrum and highly efficient bacterial inhibition has become a hot research topic in modern food safety. The antibacterial mechanisms of marine animal antimicrobial peptides are primarily mediated through the disruption of cell membranes, impairment of cell walls, and interference with intracellular substances. These peptides are recognized for their broad antibacterial spectrum, low resistance development, and low residue characteristics, and are considered potential novel antimicrobial agents to combat food spoilage. Therefore, marine animal antimicrobial peptides are proposed as promising antimicrobial agents for food preservation applications. In this paper, antimicrobial peptides derived from marine animals including fish, crustaceans (shrimp and crab), and mollusks are systematically reviewed, with their antimicrobial mechanisms and the challenges encountered in their research and application comprehensively analyzed. Additionally, feasible solutions are systematically proposed to offer theoretical and practical guidance for the sustainable development and application of marine animal antimicrobial peptides in food preservation and aquaculture

    Long-Term Telbivudine Treatment Results in Resolution of Liver Inflammation and Fibrosis in Patients with Chronic Hepatitis B

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    The long-term goal of chronic hepatitis B (CHB) treatment is improvement of liver disease and prevention of cirrhosis. The aim of this study was to assess whether prolonged telbivudine treatment improves liver inflammation and fibrosis. The primary objective was to evaluate the proportion of patients with absence/minimal inflammation (Knodell necroinflammatory score a parts per thousand currency sign3) on liver biopsy at Year 5. Fifty-seven patients aged 16-70 years with a clinical history of CHB and active viral replication (38 hepatitis B e antigen [HBeAg] positive and 19 HBeAg negative) were followed for 6 years: 33 received telbivudine 600 mg/day continuously for 5 years; 24 received lamivudine 100 mg/day for 2 years and then telbivudine for 3 years. Liver biopsies were taken pre-treatment and after 5 years of treatment. At baseline, mean (standard deviation) serum hepatitis B virus (HBV) DNA load was 8.5 (1.7) log(10) copies/mL, Knodell necroinflammatory score was 7.6 (2.9), and Ishak fibrosis score was 2.2 (1.1). After antiviral treatment (median duration: 261 weeks), liver histology improved with increased proportions of patients with absence/minimal liver inflammation (Knodell necroinflammatory score a parts per thousand currency sign3), from 16% (9/57) at baseline to 98% (56/57), and absence/minimal fibrosis (Ishak score a parts per thousand currency sign1), from 25% (14/57) at baseline to 84% (48/57). At Year 5, HBV DNA load was < 300 copies/mL for all patients; cumulative HBeAg loss and seroconversion rates were 88% and 77%, respectively. At Year 6, 95% of patients with abnormal baseline glomerular filtration rate (60-90 mL/min/1.73 m(2)) improved to normal GFR (> 90 mL/min/1.73 m(2)). Long-term telbivudine treatment with profound and durable viral suppression significantly improved liver histology, thus achieving the long-term goals of CHB treatment. FibroScan(A (R)) results after 5 and 6 years of treatment (in almost 20% of patients) were consistent with this information. Novartis and National Science and Technology Major Project (2012ZX10002003). ClinicalTrials.gov # NCT00877149.Novartis; National Science and Technology Major Project [2012ZX10002003]; Novartis Pharma AGSCI(E)[email protected]

    The Cytoplasmic Domain of MUC1 Induces Hyperplasia in the Mammary Gland and Correlates with Nuclear Accumulation of β-Catenin

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    MUC1 is an oncoprotein that is overexpressed in up to 90% of breast carcinomas. A previous in vitro study by our group demonstrated that the cytoplasmic domain of MUC1 (MUC1-CD), the minimal functional unit of MUC1, contributes to the malignant phenotype in cells by binding directly to β-catenin and protecting β-catenin from GSK3β-induced degradation. To understand the in vivo role of MUC1-CD in breast development, we generated a MUC1-CD transgenic mouse model under the control of the MMTV promoter in a C57BL/6J background, which is more resistant to breast tumor. We show that the expression of MUC1-CD in luminal epithelial cells of the mammary gland induced a hyperplasia phenotype characterized by the development of hyper-branching and extensive lobuloalveoli in transgenic mice. In addition to this hyperplasia, there was a marked increase in cellular proliferation in the mouse mammary gland. We further show that MUC1-CD induces nuclear localization of β-catenin, which is associated with a significant increase of β-catenin activity, as shown by the elevated expression of cyclin D1 and c-Myc in MMTV-MUC1-CD mice. Consistent with this finding, we observed that overexpression of MUC1-C is associated with β-catenin nuclear localization in tumor tissues and increased expression of Cyclin D1 and c-Myc in breast carcinoma specimens. Collectively, our data indicate a critical role for MUC1-CD in the development of mammary gland preneoplasia and tumorigenesis, suggesting MUC1-CD as a potential target for the diagnosis and chemoprevention of human breast cancer

    A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization

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    A key legacy of the recently launched TESS mission will be to provide the astronomical community with many of the best transiting exoplanet targets for atmospheric characterization. However, time is of the essence to take full advantage of this opportunity. JWST, although delayed, will still complete its nominal five year mission on a timeline that motivates rapid identification, confirmation, and mass measurement of the top atmospheric characterization targets from TESS. Beyond JWST, future dedicated missions for atmospheric studies such as ARIEL require the discovery and confirmation of several hundred additional sub-Jovian size planets (R_p < 10 R_Earth) orbiting bright stars, beyond those known today, to ensure a successful statistical census of exoplanet atmospheres. Ground-based ELTs will also contribute to surveying the atmospheres of the transiting planets discovered by TESS. Here we present a set of two straightforward analytic metrics, quantifying the expected signal-to-noise in transmission and thermal emission spectroscopy for a given planet, that will allow the top atmospheric characterization targets to be readily identified among the TESS planet candidates. Targets that meet our proposed threshold values for these metrics would be encouraged for rapid follow-up and confirmation via radial velocity mass measurements. Based on the catalog of simulated TESS detections by Sullivan et al. (2015), we determine appropriate cutoff values of the metrics, such that the TESS mission will ultimately yield a sample of 300\sim300 high-quality atmospheric characterization targets across a range of planet size bins, extending down to Earth-size, potentially habitable worlds.Comment: accepted to PAS

    Self‐Healing Supramolecular Hydrogels for Tissue Engineering Applications

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    Self‐healing supramolecular hydrogels have emerged as a novel class of biomaterials that combine hydrogels with supramolecular chemistry to develop highly functional biomaterials with advantages including native tissue mimicry, biocompatibility, and injectability. These properties are endowed by the reversibly cross‐linked polymer network of the hydrogel. These hydrogels have great potential for realizing yet to be clinically translated tissue engineering therapies. This review presents methods of self‐healing supramolecular hydrogel formation and their uses in tissue engineering as well as future perspectives.Self‐healing supramolecular hydrogels are a novel class of biomaterials that offer unique advantages in tissue engineering. This review describes important methods of supramolecular hydrogel formation as well as recent advances and emerging applications of these hydrogels in regenerative medicine.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147853/1/mabi201800313_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147853/2/mabi201800313.pd
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