A General Analytical Approximation to Impulse Response of 3-D Microfluidic Channels in Molecular Communication

In this paper, the impulse response for a 3-D microfluidic channel in the presence of Poiseuille flow is obtained by solving the diffusion equation in radial coordinates. Using the radial distribution, the axial distribution is then approximated accordingly. Since Poiseuille flow velocity changes with radial position, molecules have different axial properties for different radial distributions. We, therefore, present a piecewise function for the axial distribution of the molecules in the channel considering this radial distribution. Finally, we lay evidence for our theoretical derivations for impulse response of the microfluidic channel and radial distribution of molecules through comparing them using various Monte Carlo simulations.Comment: The manuscript is submitted to IEEE: Transactions on Nanobioscienc

CORNN: Convex optimization of recurrent neural networks for rapid inference of neural dynamics

Advances in optical and electrophysiological recording technologies have made it possible to record the dynamics of thousands of neurons, opening up new possibilities for interpreting and controlling large neural populations in behaving animals. A promising way to extract computational principles from these large datasets is to train data-constrained recurrent neural networks (dRNNs). Performing this training in real-time could open doors for research techniques and medical applications to model and control interventions at single-cell resolution and drive desired forms of animal behavior. However, existing training algorithms for dRNNs are inefficient and have limited scalability, making it a challenge to analyze large neural recordings even in offline scenarios. To address these issues, we introduce a training method termed Convex Optimization of Recurrent Neural Networks (CORNN). In studies of simulated recordings, CORNN attained training speeds ~100-fold faster than traditional optimization approaches while maintaining or enhancing modeling accuracy. We further validated CORNN on simulations with thousands of cells that performed simple computations such as those of a 3-bit flip-flop or the execution of a timed response. Finally, we showed that CORNN can robustly reproduce network dynamics and underlying attractor structures despite mismatches between generator and inference models, severe subsampling of observed neurons, or mismatches in neural time-scales. Overall, by training dRNNs with millions of parameters in subminute processing times on a standard computer, CORNN constitutes a first step towards real-time network reproduction constrained on large-scale neural recordings and a powerful computational tool for advancing the understanding of neural computation.Comment: Accepted at NeurIPS 202

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

Analyse génétique des adénovirus en situation clinique

Les HAdV appartiennent au genre Mastadenovirus de la famille des Adenoviridae. Ils constituent un ensemble vaste et varié de 7 espèces divisées en plus de 70 types connus à ce jour pouvant être responsables de nombreuses affections différentes, parmi lesquelles les gastro-entérites aiguës et les infections des voies respiratoires.A l’heure actuelle, leur diagnostic biologique consiste le plus souvent en l’analyse par tests de diagnostic rapide ou par biologie moléculaire des échantillons de selles ou de fluides respiratoires de patients atteints.L’objectif de ce mémoire est de réaliser d’une part un état des lieux épidémiologique des espèces et types d’HAdV ayant circulé à Marseille au cours de l’année calendaire 2017 et d’autre part une évaluation des techniques disponibles de diagnostic par PCR. Ce travail fut réalisé grâce à l’analyse à la fois par deux systèmes de qPCR, par PCR standard et enfin par séquençage Sanger sur les quelques 196 échantillons cliniques positifs (provenant d’autant de patients différents) collectés au cours de la période en question dans les différents services cliniques de l’APHM.L’analyse a permis de démontrer entre autre que les enfants sont plus souvent touchés que les adultes (médiane d’âge : 2 ans) et qu’une épidémie communautaire constituée d’HAdV de type 2 et 3 a eu lieu entre décembre 2017 et mi-janvier 2018. Du point de vue technique ce travail a également montré qu’en cas de réaction croisée en qPCR d’espèce, le résultat à retenir était dans 92% des cas celui associé au Ct le plus bas.Cette étude pourra servir à l’avenir de base pour d’autres réalisées sur un nombre plus important d’échantillons et sur de plus longues périodes