34 research outputs found

    Learning context-aware adaptive solvers to accelerate quadratic programming

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    Convex quadratic programming (QP) is an important sub-field of mathematical optimization. The alternating direction method of multipliers (ADMM) is a successful method to solve QP. Even though ADMM shows promising results in solving various types of QP, its convergence speed is known to be highly dependent on the step-size parameter ρ\rho. Due to the absence of a general rule for setting ρ\rho, it is often tuned manually or heuristically. In this paper, we propose CA-ADMM (Context-aware Adaptive ADMM)) which learns to adaptively adjust ρ\rho to accelerate ADMM. CA-ADMM extracts the spatio-temporal context, which captures the dependency of the primal and dual variables of QP and their temporal evolution during the ADMM iterations. CA-ADMM chooses ρ\rho based on the extracted context. Through extensive numerical experiments, we validated that CA-ADMM effectively generalizes to unseen QP problems with different sizes and classes (i.e., having different QP parameter structures). Furthermore, we verified that CA-ADMM could dynamically adjust ρ\rho considering the stage of the optimization process to accelerate the convergence speed further.Comment: 9 pages, 4 figure

    Tgif1 Counterbalances The Activity Of Core Pluripotency Factors In Mouse Embryonic Stem Cells

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    Core pluripotency factors, such as Oct4, Sox2, and Nanog, play important roles in maintaining embryonic stem cell (ESC) identity by autoregulatory feedforward loops. Nevertheless, the mechanism that provides precise control of the levels of the ESC core factors without indefinite amplification has remained elusive. Here, we report the direct repression of core pluripotency factors by Tgif1, a previously known terminal repressor of TGF beta/activin/nodal signaling. Overexpression of Tgif1 reduces the levels of ESC core factors, whereas its depletion leads to the induction of the pluripotency factors. We confirm the existence of physical associations between Tgif1 and Oct4, Nanog, and HDAC1/2 and further show the level of Tgif1 is not significantly altered by treatment with an activator/inhibitor of the TGF beta/activin/nodal signaling. Collectively, our findings establish Tgif1 as an integral member of the core regulatory circuitry of mouse ESCs that counterbalances the levels of the core pluripotency factors in a TGF beta/activin/nodal-independent manner.Cancer Prevention Research Institute of Texas (CPRIT) R1106Molecular Bioscience

    Assessing Food Insecurity Screening Among Healthcare Providers in Vermont

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    What influences primary care providers’ screening for food insecurity and recommending food resources? This study examined the barriers primary care providers have to screening for food insecurity and recommending resources to their patients. By analyzing the factors that drive or prevent providers from making recommendations, we can help address food insecurity within the healthcare setting • Food security is defined as having access to enough food in order to maintain an active and healthy life • An estimated 1 in 8 Americans suffer from food insecurity, which is associated with adverse health outcomes and an increase of $77.5 billion in additional healthcare costs annually • Resources exist to ease the burden of food insecurity, but these resources may be underutilized and poorly integrated within the healthcare fieldhttps://scholarworks.uvm.edu/comphp_gallery/1278/thumbnail.jp

    Cadmium carbonic anhydrase of marine diatoms: Diversity and expression

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    The enzyme carbonic anhydrase plays a key role in the acquisition of inorganic carbon for photosynthesis in phytoplankton. A recent study reported the isolation of the cadmium carbonic anhydrase (CDCA), a CA that can use either Zn or Cd as its metal center from the marine diatom, Thalassiosira weissflogii. Using degenerate primers designed from the sequences of T. weissflogii and a putative sequence in the genome of T. pseudonana, CDCA was shown to be widespread in diatom species and in the environment. Analysis of the amino acid sequence of CDCA showed that the putative Cd binding site resembles that of beta-class carbonic anhydrases. Because the use of Cd in CDCA is the only known biological function of Cd and is thought to explain the nutrient-like concentration profile of Cd in the oceans, the expression of CDCA was explored in cultures of Thalassiosira weissflogii and in samples from the Equatorial Pacific and coastal New Jersey. CDCA1 expression in T. weissflogii was highly modulated by pH changes, and induced by the addition of Cd. In samples from the Equatorial Pacific, peptide sequences matching CDCA1 were found. In samples from New Jersey coastal water, a high level of CDCA expression was found inversely correlated with pCO2. The presence of cadmium carbonic anhydrases in diatoms and in environments probably reflects the difficulty in acquiring inorganic carbon for photosynthesis. Diatoms may have become successful as the primary producers due to the ability to use Cd in carbon acquisition under conditions of very low CO2

    Retention Esophagitis as a Significant Clinical Predictor of Progression to Esophageal Cancer in Achalasia

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    Background/Aims Chronic liquid and/or food stasis caused by retention esophagitis (RE) in achalasia is a notable endoscopic finding because of the presence of a thickened or whitish esophageal mucosa and histologically altered squamous hyperplasia. We aimed to identify the clinical features of RE associated with achalasia and to clarify the clinical definition of RE in achalasia as a precancerous lesion identified by analyzing biomarker expressions. Methods From 2006 to 2015, we retrospectively reviewed 37 patients with achalasia without previous treatment. Among them, 21 patients had diagnostic findings of RE (RE+) and 16 patients had no diagnostic findings of RE (RE–). Immunohistochemical staining of p53, p16, and Ki-67 was performed on the endoscopic biopsy tissues from the patients with achalasia and 10 control patients with non-obstructive dysphagia. Results The symptom duration and transit delay were significantly longer in the RE+ group than in the RE– group. We found particularly high p53 positivity rates in the RE+ group (p<0.001). The rate of p16 expression was also significantly higher in the RE+ group than in the other two groups (p=0.003). Conclusions A high p53 expression rate was more frequently found in the RE+ group than in the other two groups. RE could be a meaningful clinical feature of achalasia for predicting esophageal carcinogenesis