62 research outputs found

    A SYSTEMC/SIMULINK CO-SIMULATION ENVIRONMENT OF THE JPEG ALGORITHM

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    In the past decades, many factors have been continuously increasing like the functionality of embedded systems as well as the time-to-market pressure has been continuously increasing. Simulation of an entire system including both hardware and software from early design stages is one of the effective approaches to improve the design productivity. A large number of research efforts on hardware/software (HW/SW) co-simulation have been made so far. Real-time operating systems have become one of the important components in the embedded systems. However, in order to validate function of the entire system, this system has to be simulated together with application software and hardware. Indeed, traditional methods of verification have proven to be insufficient for complex digital systems. Register transfer level test-benches have become too complex to manage and too slow to execute. New methods and verification techniques began to emerge over the past few years. Highlevel test-benches, assertion-based verification, formal methods, hardware verification languages are just a few examples of the intense research activities driving the verification domain

    Maladie de Takayasu et polyarthrite rhumatoïde: une association rare - à propos d’une observation

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    L’artérite de Takayasu ou maladie de Takayasu (MT) et la polyarthrite rhumatoïde (PR) et sont deux maladies inflammatoires chroniques et leur association a été rapportée dans la littérature à travers quelques observations de cas sporadiques. Nous rapportons une nouvelle observation d’une telle association. Une patiente âgée de 44 ans, diagnostiquée avec une polyarthrite rhumatoïde à facteur rhumatoïde positif, qui a développé des céphalées avec des vertiges de caractère permanent. L’examen révélait un pouls radial et huméral abolis à droite, un souffle carotidien bilatéral et une tension artérielle imprenable à droite. L’artériographie a confirmé la présence d’une atteinte de l’arc aortique type MT. Le diagnostic d’une maladie de Takayasu associée à une polyarthrite rhumatoïde était retenu. La patiente était traitée par une corticothérapie (prednisone à la dose de 0,5 mg/kg par jour) et un traitement de fond par Méthotrexate avec une bonne réponse initiale. A travers notre observation et une revue de la littérature, les caractéristiques épidémiologiques, étiopathogéniques, cliniques, thérapeutiques et évolutives de cette association seront discutées. Pan African Medical Journal 2012; 12:6

    Does COVID-19 contribute to development of neurological disease?

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    Background: Although coronavirus disease 2019 (COVID-19) has been associated primarily with pneumonia, recent data show that the causative agent of COVID-19, the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can infect a large number of vital organs beyond the lungs, such as the heart, kidneys, and the brain. Thus, there is evidence showing possible retrograde transmission of the virus from the olfactory epithelium to regions of the brain stem. Methods: This is a literature review article. The research design method is an evidence-based rapid review. The present discourse aim is first to scrutinize and assess the available literature on COVID-19 repercussion on the central nervous system (CNS). Standard literature and database searches were implemented, gathered relevant material, and extracted information was then assessed. Results: The angiotensin-converting enzyme 2 (ACE2) receptors being the receptor for the virus, the threat to the central nervous system is expected. Neurons and glial cells express ACE2 receptors in the CNS, and recent studies suggest that activated glial cells contribute to neuroinflammation and the devastating effects of SARS-CoV-2 infection on the CNS. The SARS-CoV-2-induced immune-mediated demyelinating disease, cerebrovascular damage, neurodegeneration, and depression are some of the neurological complications discussed here. Conclusion: This review correlates present clinical manifestations of COVID-19 patients with possible neurological consequences in the future, thus preparing healthcare providers for possible future consequences of COVID-19

    Sleep Deprivation and Neurological Disorders

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    Sleep plays an important role in maintaining neuronal circuitry, signalling and helps maintain overall health and wellbeing. Sleep deprivation (SD) disturbs the circadian physiology and exerts a negative impact on brain and behavioural functions. SD impairs the cellular clearance of misfolded neurotoxin proteins like α-synuclein, amyloid-β, and tau which are involved in major neurodegenerative diseases like Alzheimer\u27s disease and Parkinson\u27s disease. In addition, SD is also shown to affect the glymphatic system, a glial-dependent metabolic waste clearance pathway, causing accumulation of misfolded faulty proteins in synaptic compartments resulting in cognitive decline. Also, SD affects the immunological and redox system resulting in neuroinflammation and oxidative stress. Hence, it is important to understand the molecular and biochemical alterations that are the causative factors leading to these pathophysiological effects on the neuronal system. This review is an attempt in this direction. It provides up-to-date information on the alterations in the key processes, pathways, and proteins that are negatively affected by SD and become reasons for neurological disorders over a prolonged period of time, if left unattended

    Effect of Exogenous Fibrolytic Enzymes Supplementation or Functional Feed Additives on In Vitro Ruminal Fermentation of Chemically Pre-Treated Sunflower Heads

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    peer reviewedThis study aims to provide possible utilization of sunflower head byproduct (SFH) as a feedstuff by implementing chemical pretreatments (4% sodium hydroxide (SFHNaOH) or 4% urea (SFHurea) and supplementation with either exogenous fibrolytic enzymes (EFE) or functional feed additive (FFA). The experimental EFE was a complex (1:1, v/v) of two enzyme products with high activity of β-1,3-1,4-glucanase and endo-1,4-β-D-xylanase and applied at 0 (SFHout), 1, 2, 5, and 10 µL/ gdry matter, while FFA was a fermentation byproduct rich in cellulase and xylanase activities, applied at 0 (SFHout), 0.5, 1, 2, and 4 mg/g DM. SFHurea had the highest (p < 0.05) crude protein (CP) content compared to other SFH substrates. Linear enhancements (p < 0.05) in kinetics of gas production (GP), metabolizable energy (ME), organic matter digestibility (OMD) and total short-chain fatty acids (SCFAs) concentrations were observed for all SFH substrates supplemented with EFE. The SFHout had the highest (p < 0.05) potential GP, maximum rate (Rmax) of GP, ME, OMD and SCFAs. Supplementation of EFE was more pronounced than FFA in affecting the kinetic parameters of in vitro GP for all SFH substrates. SFHout supplemented with EFE seems to be the most promising substrate to enhance microbial fermentation in vitro

    Sleep deprivation and neurological disorders

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    Sleep plays an important role in maintaining neuronal circuitry, signalling and helps maintain overall health and wellbeing. Sleep deprivation (SD) disturbs the circadian physiology and exerts a negative impact on brain and behavioural functions. SD impairs the cellular clearance of misfolded neurotoxin proteins like α-synuclein, amyloid-β, and tau which are involved in major neurodegenerative diseases like Alzheimer's disease and Parkinson's disease. In addition, SD is also shown to affect the glymphatic system, a glial-dependent metabolic waste clearance pathway, causing accumulation of misfolded faulty proteins in synaptic compartments resulting in cognitive decline. Also, SD affects the immunological and redox system resulting in neuroinflammation and oxidative stress. Hence, it is important to understand the molecular and biochemical alterations that are the causative factors leading to these pathophysiological effects on the neuronal system. This review is an attempt in this direction. It provides up-to-date information on the alterations in the key processes, pathways, and proteins that are negatively affected by SD and become reasons for neurological disorders over a prolonged period of time, if left unattended

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Analyse de la dynamique de certains modèles proie-prédateur et applications

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    This thesis is devoted to the study of the dynamics of some problems Leslie Gower-type predator-prey with ordinary differential equations and reaction-diffusion equations. The main objective is to make mathematical analysis, numerical simulation of constructed models. The thesis is divided in three parts : The first part is devoted to a predator-prey system with prey harvesting, the model is given by an ordinary differential equation system. The aim of this part is to study the impact of harvesting on the system behavior. In the second part, we introduce the spatial dimension in the dynamic model considered without harvesting, modeling a food chain of two species with diffusion on the circular area and Holling Type II response function. We perform a complete theoretical analysis of the spatiotemporal dynamics model built and the system study on the circular area. A similar mathematical study is conducted as part of the functional response of Benddington-DeAngelis.We study, also the qualitative behavior of a food chain of three species with a Holling type II response function. In the last party, we introduce of cross-diffusion terms in the considered dynamic model in order to have the effect of the latter on the system behavior.Cette thèse est consacrée à l’étude de la dynamique de quelques problèmes de proie-prédateur de type Leslie-Gower avec des systèmes d’équations différentielles ordinaires et des équations de réaction-diffusion. L’objectif principal est de faire l’analyse mathématique, la simulation numérique des modèles construits. La thèse est divisée en trois parties : La première partie est consacrée à un système proie-prédateur avec récolte de proie, le modèle est donné par un système d’équation différentielle ordinaire. Le but de cette partie est d’étudier l’impact de la récolte sur le comportement du système. Dans la deuxième partie, nous introduisons la dimension spatiale dans le modèle dynamique considéré sans récolte, modélisant une chaîne alimentaire de deux espèces avec diffusion sur un domaine circulaire et une fonction de réponse de Holling type II. Nous effectuons une analyse théorique complète de la dynamique spatio-temporelle du modèle construit ainsi que l’étude du système sur le domaine circulaire. Une étude mathématique similaire est menée dans le cadre de la réponse fonctionnelle de Benddington-DeAngelis. Nous étudions, aussi le comportement qualitatif d’une chaîne alimentaire de trois espèces avec une réponse fonctionnelle de Holling type II. Dans la dernière partie, nous introduisons des termes de diffusions croisées dans le modèle dynamique considéré dans le but d’avoir l’effet de ce dernier sur le comportement du système
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