1,472 research outputs found
Integrable and superintegrable systems associated with multi-sums of products
We construct and study certain Liouville integrable, superintegrable, and
non-commutative integrable systems, which are associated with multi-sums of
products.Comment: 26 pages, submitted to Proceedings of the royal society
Evaluation of coagulation activation after Rhinovirus infection in patients with asthma and healthy control subjects: an observational study
Background Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance. Methods 28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation). Results 13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01). Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1. Conclusions Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load
Maximum Class Separation as Inductive Bias in One Matrix
Maximizing the separation between classes constitutes a well-known inductive bias in machine learning and a pillar of many traditional algorithms. By default, deep networks are not equipped with this inductive bias and therefore many alternative solutions have been proposed through differential optimization. Current approaches tend to optimize classification and separation jointly: aligning inputs with class vectors and separating class vectors angularly. This paper proposes a simple alternative: encoding maximum separation as an inductive bias in the network by adding one fixed matrix multiplication before computing the softmax activations. The main observation behind our approach is that separation does not require optimization but can be solved in closed-form prior to training and plugged into a network. We outline a recursive approach to obtain the matrix consisting of maximally separable vectors for any number of classes, which can be added with negligible engineering effort and computational overhead. Despite its simple nature, this one matrix multiplication provides real impact. We show that our proposal directly boosts classification, long-tailed recognition, out-of-distribution detection, and open-set recognition, from CIFAR to ImageNet. We find empirically that maximum separation works best as a fixed bias; making the matrix learnable adds nothing to the performance. The closed-form implementation and code to reproduce the experiments are available on github
Online automatic tuning and control for fed-batch cultivation
Performance of controllers applied in biotechnological production is often below expectation. Online automatic tuning has the capability to improve control performance by adjusting control parameters. This work presents automatic tuning approaches for model reference specific growth rate control during fed-batch cultivation. The approaches are direct methods that use the error between observed specific growth rate and its set point; systematic perturbations of the cultivation are not necessary. Two automatic tuning methods proved to be efficient, in which the adaptation rate is based on a combination of the error, squared error and integral error. These methods are relatively simple and robust against disturbances, parameter uncertainties, and initialization errors. Application of the specific growth rate controller yields a stable system. The controller and automatic tuning methods are qualified by simulations and laboratory experiments with Bordetella pertussis
The impact of patent expiry on drug prices:insights from the Dutch market
Background: Currently literature on the impact of patent expiry on drug prices is lacking. Objective: To determine the impact of patent expiration and generic entry on drug prices in the Netherlands. Methods: Prescription and price data from 1999 up to and including December 2016 were collected from two national databases. The overall price ratio of drugs prices up to 48 months after patent expiration was compared to the price in the month before expiry. Sub-analyses were performed to provide insights in generic uptake, length of market exclusivity and price development for originators and generics separately. Results: In total 250 drugs faced patent expiration during the study period. Forty-eight months after patent expiration the median price ratio decreased to 0.59 (IQR = 0.23-0.86) compared to the month prior patent expiry. Major differences in price developments were observed depending on the level of revenue prior to patent expiration and the time of patent expiration with ratios ranging from 0.08 (IQR = 0.07-0.16) to 0.81 (IQR = 0.62-0.97). Prior to patent expiry, the price decreased by 2.3% annually while having market exclusivity for 11.3 years on average. Conclusion: This study showed that the median drug price after patent expiration decreased by 41% after 4 years. The results of this study can be used to provide more reliable estimates on drug prices over its lifecycle and can be implemented in economic evaluations to inform the cost-effectiveness and long-term budget impact of new drugs
Патогенетические механизмы повреждений бета-клеток панкреатических островков при диабете и влияние прерывистой гипоксии
У щурів з експериментальним цукровим діабетом та впливом на них переривчастої гіпоксії вивчені особливості синтезу інсуліну, цитоархітектоніки бета-клітин та експресія маркерів апоптозу та проліферації. Кількість бета-клітин підвищується, концентрація інсуліну залишається в межах інтактного показника. Значною мірою підвищується вироблення антиапоптотичного білку Bcl2. Гіпокситерапія призводить до суттєвого підвищення проліферативної активності ендокриноцитів панкреатичних острівців.At rats with an experimental diabetes and influence on intermittent hypoxia, features of synthesis of insulin, cells-architectonics beta-cells and an expression of markers apoptotic and proliferative are studied. Amount beta-cells increase, and concentration of insulin remains border of a control indicator. The production of anti-apoptotic protein Bcl2 increase to a considerable extent. Intermittent hypoxia significantly increase the proliferative activity endokrinotsitis pancreatic islets
Enhancement-mode PEDOT:PSS organic electrochemical transistors using molecular de-doping
Organic electrochemical transistors (OECTs) show great promise for flexible, low-cost, and low-voltage sensors for aqueous solutions. The majority of OECT devices are made using the polymer blend poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), in which PEDOT is intrinsically doped due to inclusion of PSS. Because of this intrinsic doping, PEDOT:PSS OECTs generally operate in depletion mode, which results in a higher power consumption and limits stability. Here, a straightforward method to de-dope PEDOT:PSS using commercially available amine-based molecular de-dopants to achieve stable enhancement-mode OECTs is presented. The enhancement-mode OECTs show mobilities near that of pristine PEDOT:PSS (≈2 cm2 V−1 s−1) with stable operation over 1000 on/off cycles. The electron and proton exchange among PEDOT, PSS, and the molecular de-dopants are characterized to reveal the underlying chemical mechanism of the threshold voltage shift to negative voltages. Finally, the effect of the de-doping on the microstructure of the spin-cast PEDOT:PSS films is investigated.</p
The Value of Preventative Dental Care:A Discrete-Choice Experiment
Acknowledgments We thank all of the respondents to our survey who took the time to share their opinions and preferences with us, as well as all members of the IQuaD study team who provided input, advice, and comments on draft versions of the survey. Open Access via the Jisc Sage Open Access Agreement Funder - national institute for health research 10.13039/501100000272 09/01/45 Funding The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The project was funded by the UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme (project number: 09/01/45). The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Department of Health or the funders that provide institutional support for the authors of this report. The Health Economics Research Unit and the Health Services Research Unit are funded by the Chief Scientist Office of the Scottish Government Health and Social Care DirectoratesPeer reviewedPublisher PD
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