248 research outputs found

    Approximating the long time average of the density operator: Diagonal ensemble

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    Structural Breaks, Long Memory, or Unit Roots in Stock Prices: Evidence from Emerging Markets

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    This paper investigates whether daily stock price indices from fourteen emerging markets are random walk (unit root) or mean reverting long memory processes. We use an efficient statistical framework that tests for random walks in the presence of multiple structural breaks at unknown dates. This approach allows us to investigate a broader range of persistence than that allowed by the I(0)/I(1) paradigm about the order of integration, which is usually implemented for testing the random walk hypothesis in stock market indices. Our approach extends Robinson’s (1994) efficient test of unit root against fractional integration to allow for multiple endogenously determined structural breaks. For almost all countries, we find support for the random walk hypothesis, with the exception of four stock markets, where weak evidence of mean reverting long memory exist. Structural breaks have impact on the unit root behavior only for Mexico; for all other 11 markets unit roots exist even when structural breaks are not taken into account. In order to check the robustness of our results, we use the two-step feasible exact local Whittle (FELW2ST) estimator of Shimotsu (2010), which allows for polynomial trends, non-normal distributions, and non-stationarity. The results from the semi-parametric FELW2ST approach shows that, except for Mexico, stock price indices of 13 emerging markets are not mean reverting

    Heterogeneous Delays in Neural Networks

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    We investigate heterogeneous coupling delays in complex networks of excitable elements described by the FitzHugh-Nagumo model. The effects of discrete as well as of uni- and bimodal continuous distributions are studied with a focus on different topologies, i.e., regular, small-world, and random networks. In the case of two discrete delay times resonance effects play a major role: Depending on the ratio of the delay times, various characteristic spiking scenarios, such as coherent or asynchronous spiking, arise. For continuous delay distributions different dynamical patterns emerge depending on the width of the distribution. For small distribution widths, we find highly synchronized spiking, while for intermediate widths only spiking with low degree of synchrony persists, which is associated with traveling disruptions, partial amplitude death, or subnetwork synchronization, depending sensitively on the network topology. If the inhomogeneity of the coupling delays becomes too large, global amplitude death is induced

    INCF/OCNS Software Working Group

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    Neuroscience cannot exist without its ecosystem of community-developed software tools that many of us rely heavily upon. The newly established Software Working Group, a community working group shared by the International Neuroinformatics Coordinating Facility (INCF) and the Organization for Computational Neurosciences (OCNS), aims to undertake activities that focus on these software tools. Members of the working group will find and discuss relevant software tools, learn and teach how to use them, test and review them, and report bugs to inform tool developers of issues when required. The working group will also strive to learn how these tools work to get involved in their development and maintenance. The aim is to ensure that the tools that our community depends on continue to be maintained by actively engaged community members, and to bring end users into close collaboration with tool developers. Since the working group includes many tool developers, it also serves as a platform to exchange design and development ideas, and will assist in improving interoperability between related tools. Another related goal of the working group is to help members define, improve, and teach transferable skills in the area of modern research software development, particularly in but not limited to, computational neuroscience. The working group is designed to be flexible, instead of being linked to a particular goal. This approach allows the group to pursue timely projects that its members value and are interested in working on. The current goals of the working group are: - To set up and maintain a living document of the current best practices in research software development to serve as a reference for the research community, especially tool developers - To host regular “developer sessions” where developer teams of various tools discuss their development pipelines (or workflows)—to disseminate various development practices, and help potential contributors get started. The activities of the working group can be followed on its website at https://ocns.github.io/SoftwareWG

    Phylogeny and evolution of infectious bursal disease virus circulating in Turkish broiler flocks

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    The emergence of new infectious bursal disease virus (IBDV) variants can threaten poultry health and production all over the world causing significant economic losses. Therefore, this study was performed to determine IBDV molecular epidemilogy, VP2 gene variation, and corresponding pathological lesions in IBDV infected chickens in Turkey. For this, 1855 bursa of Fabricius samples were collected from 371 vaccinated broiler flocks. Atrophia and haemorrhages were seen in the bursa Fabricius of very virulent IBDV (vvIBDV) infected chickens. Partial VP2 gene was sequenced and phylogenetic, recombination, and evolutionary analyses were performed. 1548 (83.5%) out of 1855 of bursa of Fabricius samples were IBDV positive and 1525 of those could be sequenced. The recombination analysis did not detect occurrence of any recombination event among the Turkish strains. Among 1525 sequenced samples, 1380 of them were found to be classical strains. Among 1380 classical strains, 1317 were similar to IBDV 2512, 11 to Faragher 52/70, 40 to 228 E, and 12 to Lukert strain. Out of 1525 reverse transcriptase ploymerase chain reaction positive samples, 144 of them were found to be similar to vvIBDV-VP2 gene reported to GenBank previously. The phylogenetic tree performed on a broad sequence dataset demonstrated grouping of vvIBDV Turkish strains in three different clusters, including sequences collected also from Iraq and Kuwait (Cluster 1), Indian (Cluster 2), and a distinct Turkish-only cluster (Cluster 3). The evolutionary rate estimation on branches/clades including Turkish strain mirrored the expected one for RNA viruses and no significant differences were found among different considered branches. In conclusion, results of this study indicate that vvIBDV strains similar to those circulating in various countries in the Middle East are present and undergoing evolution in chickens from Turkish broiler flocks. This point needs to be taken into account in planning adequate control strategies

    An unusual case of a microscopic alveolar adenoma coexisting with lung carcinoma: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>Alveolar adenomas are extremely rare, benign, primary lung tumors of unknown histogenesis that are characterized by proliferative type II alveolar epithelium and septal mesenchyma. Mostly incidental, they are clinically important as they can imitate benign primary and secondary malignant tumors and at times are difficult to differentiate from early-stage lung cancer. We describe the case of a 59-year-old man with an incidental microscopic alveolar adenoma coexisting with poorly differentiated lung carcinoma.</p> <p>Case presentation</p> <p>A 59-year-old Caucasian man with a medical history of smoking and chronic obstructive pulmonary disease was incidentally found to have a right upper lobe mass while undergoing a computed tomographic chest scan as part of a chronic obstructive pulmonary disease clinical trial. Our patient underwent a right upper lobectomy after a bronchoscopic biopsy of the mass revealed the mass to be a carcinoma. A pathological examination revealed an incidental, small, 0.2 cm, well circumscribed lesion on the staple line margin of the lobectomy in addition to the carcinoma. Histopathological and immunohistochemical examinations revealed the lesion to be an alveolar adenoma.</p> <p>Conclusions</p> <p>We report the rare presentation of a microscopic alveolar adenoma coexisting with lung carcinoma. Alveolar adenoma is an entirely benign incidental neoplasm that can be precisely diagnosed using immunohistochemical analysis in addition to its unique histopathological characteristics.</p

    Chest trauma experience over eleven-year period at al-mouassat university teaching hospital-Damascus: a retrospective review of 888 cases

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    <p>Abstract</p> <p>Background</p> <p>Thoracic trauma is one of the leading causes of morbidity and mortality in developing countries. In this study, we present our 11-year experience in the management and clinical outcome of 888 chest trauma cases as a result of blunt and penetrating injuries in our university hospital in Damascus, Syria.</p> <p>Methods</p> <p>We reviewed files of 888 consequent cases of chest trauma between January 2000 and January 2011. The mean age of our patients was 31 ± 17 years mostly males with blunt injuries. Patients were evaluated and compared according to age, gender, etiology of trauma, thoracic and extra-thoracic injuries, complications, and mortality.</p> <p>Results</p> <p>The leading cause of the trauma was violence (41%) followed by traffic accidents (33%). Pneumothorax (51%), Hemothorax (38%), rib fractures (34%), and lung contusion (15%) were the most common types of injury. Associated injuries were documented in 36% of patients (extremities 19%, abdomen 13%, head 8%). A minority of the patients required thoracotomy (5.7%), and tube thoracostomy (56%) was sufficient to manage the majority of cases. Mean hospital LOS was 4.5 ± 4.6 days. The overall mortoality rate was 1.8%, and morbidity (n = 78, 8.7%).</p> <p>Conclusions</p> <p>New traffic laws (including seat belt enforcement) reduced incidence and severity of chest trauma in Syria. Violence was the most common cause of chest trauma rather than road traffic accidents in this series, this necessitates epidemiologic or multi-institutional studies to know to which degree violence contributes to chest trauma in Syria. The number of fractured ribs can be used as simple indicator of the severity of trauma. And we believe that significant neurotrauma, traffic accidents, hemodynamic status and GCS upon arrival, ICU admission, ventilator use, and complication of therapy are predictors of dismal prognosis.</p

    Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet

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    \ua9 2024 The AuthorsIn the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI

    Low dimensional nanostructures of fast ion conducting lithium nitride

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    As the only stable binary compound formed between an alkali metal and nitrogen, lithium nitride possesses remarkable properties and is a model material for energy applications involving the transport of lithium ions. Following a materials design principle drawn from broad structural analogies to hexagonal graphene and boron nitride, we demonstrate that such low dimensional structures can also be formed from an s-block element and nitrogen. Both one- and two-dimensional nanostructures of lithium nitride, Li3N, can be grown despite the absence of an equivalent van der Waals gap. Lithium-ion diffusion is enhanced compared to the bulk compound, yielding materials with exceptional ionic mobility. Li3N demonstrates the conceptual assembly of ionic inorganic nanostructures from monolayers without the requirement of a van der Waals gap. Computational studies reveal an electronic structure mediated by the number of Li-N layers, with a transition from a bulk narrow-bandgap semiconductor to a metal at the nanoscale

    A Scalable and License Free 5G Internet of Radio Light Architecture for Services in Homes & Businesses

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    In this paper we present a 5G Internet Radio-Light (IoRL) architecture for homes that can be readily deployed because it utilizes unlicensed visible light and millimeter wave part of the spectrum, which does not require Mobile Network Operator (MNO) permission to deploy and which is used to provide inhabitants of houses with accurate location, interaction, access to Internet and Cloud based services such as high resolution video on a Tablet PC. The paper describes the home use cases and the IoRL architecture.EU Horizon 202
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