1,087 research outputs found

    Fast Primal-Dual Gradient Method for Strongly Convex Minimization Problems with Linear Constraints

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    In this paper we consider a class of optimization problems with a strongly convex objective function and the feasible set given by an intersection of a simple convex set with a set given by a number of linear equality and inequality constraints. A number of optimization problems in applications can be stated in this form, examples being the entropy-linear programming, the ridge regression, the elastic net, the regularized optimal transport, etc. We extend the Fast Gradient Method applied to the dual problem in order to make it primal-dual so that it allows not only to solve the dual problem, but also to construct nearly optimal and nearly feasible solution of the primal problem. We also prove a theorem about the convergence rate for the proposed algorithm in terms of the objective function and the linear constraints infeasibility.Comment: Submitted for DOOR 201

    Complexity and Inapproximability Results for Parallel Task Scheduling and Strip Packing

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    We study the Parallel Task Scheduling problem Pm∣sizej∣Cmax⁥Pm|size_j|C_{\max} with a constant number of machines. This problem is known to be strongly NP-complete for each m≄5m \geq 5, while it is solvable in pseudo-polynomial time for each m≀3m \leq 3. We give a positive answer to the long-standing open question whether this problem is strongly NPNP-complete for m=4m=4. As a second result, we improve the lower bound of 1211\frac{12}{11} for approximating pseudo-polynomial Strip Packing to 54\frac{5}{4}. Since the best known approximation algorithm for this problem has a ratio of 43+Δ\frac{4}{3} + \varepsilon, this result narrows the gap between approximation ratio and inapproximability result by a significant step. Both results are proven by a reduction from the strongly NPNP-complete problem 3-Partition

    Pembrolizumab alone or in combination with chemotherapy as first-line therapy for patients with advanced gastric or gastroesophageal junction adenocarcinoma: results from the phase II nonrandomized KEYNOTE-059 study

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    BACKGROUND: The multicohort, phase II, nonrandomized KEYNOTE-059 study evaluated pembrolizumab ± chemotherapy in advanced gastric/gastroesophageal junction cancer. Results from cohorts 2 and 3, evaluating first-line therapy, are presented. METHODS: Patients ≄ 18 years old had previously untreated recurrent or metastatic gastric/gastroesophageal junction adenocarcinoma. Cohort 3 (monotherapy) had programmed death receptor 1 combined positive score ≄ 1. Cohort 2 (combination therapy) received pembrolizumab 200 mg on day 1, cisplatin 80 mg/m2 on day 1 (up to 6 cycles), and 5-fluorouracil 800 mg/m2 on days 1-5 of each 3-week cycle (or capecitabine 1000 mg/m2 twice daily in Japan). Primary end points were safety (combination therapy) and objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 by central review, and safety (monotherapy). RESULTS: In the combination therapy and monotherapy cohorts, 25 and 31 patients were enrolled; median follow-up was 13.8 months (range 1.8-24.1) and 17.5 months (range 1.7-20.7), respectively. In the combination therapy cohort, grade 3/4 treatment-related adverse events occurred in 19 patients (76.0%); none were fatal. In the monotherapy cohort, grade 3-5 treatment-related adverse events occurred in seven patients (22.6%); one death was attributed to a treatment-related adverse event (pneumonitis). The objective response rate was 60.0% [95% confidence interval (CI), 38.7-78.9] (combination therapy) and 25.8% (95% CI 11.9-44.6) (monotherapy). CONCLUSIONS: Pembrolizumab demonstrated antitumor activity and was well tolerated as monotherapy and in combination with chemotherapy in patients with previously untreated advanced gastric/gastroesophageal junction adenocarcinoma

    Somatostatin treatment attenuates proteinuria and prevents weight loss in NZB/W F1 mice

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    Somatostatin, a naturally occurring neuropeptide, is an immunomodulator which inhibits humoral and cell mediated immunity as well as secretion of proinflammatory cytokines. The objective of this study was to examine the effects of a somatostatin analogue on the severity of glomerulonephritis in the female NZB/W F1 murine model of systemic lupus erythematosus (SLE). Twenty female NZB/W F1 mice were treated at 23 weeks of age with 10 mg/kg of the somatostatin analogue Sandostatin-LAR, IM every four weeks. Ten control mice received IM injection of vehicle. Mice were assessed at fourweek intervals for weight change, proteinuria, anti-DNA antibodies and splenocyte cytokine profile. The mice were sacrificed at age 34.5 weeks. Kidneys were collected and evaluated by light and immunofluorescence (IF) microscopy. Spleens were collected and splenocyte intracellular cytokines were measured by FACS analysis. In the treatment group significantly less proteinuria was observed four weeks after the second somatostatin analogue injection (dipstik scale: Ï©2.07 Ïź 0.95 versus. Ï©3.5 Ïź 1.08, P Ï­ 0.0002). The treated mice did not lose weight while the control group lost weight over time (P Ï­ 0.016). No differences were noted between the groups in anti-DNA antibody titres, cytokine profile or the severity of lupus nephritis as assessed by light and IF microscopy. Somatostatin analogue treatment attenuated proteinuria and prevented weight loss in NZB/W F1 mice, suggesting a possible beneficial effect on renal parameters and systemic manifestations of the disease. Further studies will be needed to assess the value of somatostatin analogue treatment in lupus nephritis, utilizing higher doses, at different stages of the disease, for longer periods. Lupus (2006) 15, 526-531

    Particulate metal exposures induce plasma metabolome changes in a commuter panel study

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    Introduction Advances in liquid chromatography-mass spectrometry (LC-MS) have enabled high-resolution metabolomics (HRM) to emerge as a sensitive tool for measuring environmental exposures and corresponding biological response. Using measurements collected as part of a large, panel-based study of car commuters, the current analysis examines in-vehicle air pollution concentrations, targeted inflammatory biomarker levels, and metabolomic profiles to trace potential metabolic perturbations associated with on-road traffic exposures. Methods A 60-person panel of adults participated in a crossover study, where each participant conducted a highway commute and randomized to either a side-street commute or clinic exposure session. In addition to in-vehicle exposure characterizations, participants contributed pre- and post-exposure dried blood spots for 2-hr changes in targeted proinflammatory and vascular injury biomarkers and 10-hr changes in the plasma metabolome. Samples were analyzed on a Thermo QExactive MS system in positive and negative electrospray ionization (ESI) mode. Data were processed and analyzed in R using apLCMS, xMSanalyzer, and limma. Features associated with environmental exposures or biological endpoints were identified with a linear mixed effects model and annotated through human metabolic pathway analysis in mummichog. Results HRM detected 10-hr perturbations in 110 features associated with in-vehicle, particulate metal exposures (Al, Pb, and Fe) which reflect changes in arachidonic acid, leukotriene, and tryptophan metabolism. Two-hour changes in proinflammatory biomarkers hs-CRP, IL-6, IL-8, and IL-1ÎČ were also associated with 10-hr changes in the plasma metabolome, suggesting diverse amino acid, leukotriene, and antioxidant metabolism effects. A putatively identified metabolite, 20-OH-LTB4, decreased after in-vehicle exposure to particulate metals, suggesting a subclinical immune response. Conclusions Acute exposures to traffic-related air pollutants are associated with broad inflammatory response, including several traditional markers of inflammation

    Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

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    Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≄ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters

    GeneCards Version 3: the human gene integrator

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    GeneCards (www.genecards.org) is a comprehensive, authoritative compendium of annotative information about human genes, widely used for nearly 15 years. Its gene-centric content is automatically mined and integrated from over 80 digital sources, resulting in a web-based deep-linked card for each of >73 000 human gene entries, encompassing the following categories: protein coding, pseudogene, RNA gene, genetic locus, cluster and uncategorized. We now introduce GeneCards Version 3, featuring a speedy and sophisticated search engine and a revamped, technologically enabling infrastructure, catering to the expanding needs of biomedical researchers. A key focus is on gene-set analyses, which leverage GeneCards’ unique wealth of combinatorial annotations. These include the GeneALaCart batch query facility, which tabulates user-selected annotations for multiple genes and GeneDecks, which identifies similar genes with shared annotations, and finds set-shared annotations by descriptor enrichment analysis. Such set-centric features address a host of applications, including microarray data analysis, cross-database annotation mapping and gene-disorder associations for drug targeting. We highlight the new Version 3 database architecture, its multi-faceted search engine, and its semi-automated quality assurance system. Data enhancements include an expanded visualization of gene expression patterns in normal and cancer tissues, an integrated alternative splicing pattern display, and augmented multi-source SNPs and pathways sections. GeneCards now provides direct links to gene-related research reagents such as antibodies, recombinant proteins, DNA clones and inhibitory RNAs and features gene-related drugs and compounds lists. We also portray the GeneCards Inferred Functionality Score annotation landscape tool for scoring a gene’s functional information status. Finally, we delineate examples of applications and collaborations that have benefited from the GeneCards suite

    Tribological performance of novel Nickel-based composite coatings with lubricant particles

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    Abstract The present study is focused on the evaluation of the tribological performance of novel Ni/hBN and Ni/WS2 composite coatings electrodeposited from an additive-free Watts bath with the assistance of ultrasound. Lubricated and non-lubricated scratch tests were performed on both novel composite coatings and on standard Ni deposits used as a benchmark coating to have an initial idea of the effect of the presence of particles within the Ni matrix. Under lubricated conditions, the performance of the Ni/hBN composite coating was very similar to the benchmark Ni coating, whereas the Ni/WS2 behaved quite differently, as the latter did not only show a lower coefficient of friction, but also prevented the occurrence of stick-slip motion that was clearly observed in the other coatings. Under non-lubricated conditions, whereas the tribological performance of the Ni/hBN composite coating was again very similar to that of the benchmark Ni coating, the Ni/WS2 composite coatings again showed a remarkable enhancement, as the incorporation of the WS2 particles into the Ni coating not only resulted in a lower coefficient of friction, but also in the prevention of coating failure
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