Cadenes de Markov i la seva aplicació a la neurofı́sica

Treballs Finals de Grau de Matemàtiques, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2016, Director: Olga Julià de FerranMarkov chains are primarily characterized by the probability distribution of their next state solely depending on their current one. This specific trait has enabled Markov chains to be applied in various fields of study, such as chemistry, economics and music. By expanding the theory of Markov chains to higher order Markov chains, where the probability distribution of their next state depends on their current one as well as on past ones, they also have an application in neurophysics. This work will study the theory behind Markov chains, going through higher order Markov chains and finally arriving to the expression of a powerful mathematical tool called transfer entropy, which quantifies the directionality and strength of connections among neurons, helping to shed some light into the mysteries of the brain

Transfer entropy: how to further understand connections among neurons

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2016, Tutor: Jordi Soriano FraderaMuch time and effort is being put to shed some light into the mysteries of the brain, and yet so much of it still remains unknown. This is why understanding the human brain and mind is considered one of the grand challenges of the XXI Century [1]. By implementing the recently developed information measure called Transfer Entropy, the strength and directionality of connections among neurons can be quantified. By the means of this mathematical tool, applied to trains of neuronal activity data measured in cultured neuronal networks, the structure of a neuronal network of 1,412 neurons has been analyzed and quantifie

Die COVID-19-Pandemie: Die Rolle von Demografie und Demograf*innen

Die COVID-19-Todesfälle sind nur die Spitze eines Eisbergs. Staatliche Maßnahmen zur Unterstützung von Familien könnten die Auswirkungen der Pandemie auf andere demografische Ereignisse, wie zum Beispiel die Fertilität, abmildern. - Bei der Bekämpfung von COVID-19 sollten politische Entscheidungsträger*innen berücksichtigen, inwiefern die Altersstruktur und Formen des Zusammenlebens die Infektionsund Todeszahlen beeinflussen können. - Auf nationaler Ebene müssen die statistischen Ämter ihre Datenerfassungssysteme verbessern, sodass auf Registerdaten besser und schneller zugegriffen werden kann. - Das Ausmaß der Übersterblichkeit variiert stark zwischen europäischen Ländern, und auch innerhalb eines Landes gibt es deutliche Unterschiede. Die genauen Gründe für den Erfolg oder Misserfolg einer Region stehen noch nicht fest, sodass in diesem Bereich mehr Forschung notwendig ist

Applying Short-term Memory to Social Search Agents

AbstractThis paper presents about our research in social search. Generally, the research in social search falls into two principal challenges. The first challenge is how to find more relevant answers to the question. The second one is how to increase speed in finding relevant answers.Recently, we had provided two algorithms called Asknext and Question Waves to find more relevant answers compared to the baseline algorithm BFS. But, the search speed of the two proposed algorithms still the subject to improve.In this paper, we introduce the agents’ ability of learning the answers from the interactions with other agents so that they can quickly answer the question of other agents. We model this learning process by implementing the concept of data caching as the short-term memory of each social search agent. The result improvement of the speediness and the reduction of the number of messages used to communicate between agents, after apply agent's short-term memory concept, demonstrates the usefulness of the proposed approach

Negotiation-Style Recommender Based on Computational Ecology in Open Negotiation Environments.

The system described herein represents the first example of a recommender system in digital ecosystems where agents negotiate services on behalf of small companies. The small companies compete not only with price or quality, but with a wider service-by-service composition by subcontracting with other companies. The final result of these offerings depends on negotiations at the scale of millions of small companies. This scale requires new platforms for supporting digital business ecosystems, as well as related services like open-id, trust management, monitors and recommenders. This is done in the Open Negotiation Environment (ONE), which is an open-source platform that allows agents, on behalf of small companies, to negotiate and use the ecosystem services, and enables the development of new agent technologies. The methods and tools of cyber engineering are necessary to build up Open Negotiation Environments that are stable, a basic condition for predictable business and reliable business environments. Aiming to build stable digital business ecosystems by means of improved collective intelligence, we introduce a model of negotiation style dynamics from the point of view of computational ecology. This model inspires an ecosystem monitor as well as a novel negotiation style recommender. The ecosystem monitor provides hints to the negotiation style recommender to achieve greater stability of an open negotiation environment in a digital business ecosystem. The greater stability provides the small companies with higher predictability, and therefore better business results. The negotiation style recommender is implemented with a simulated annealing algorithm at a constant temperature, and its impact is shown by applying it to a real case of an open negotiation environment populated by Italian companies.Fil: De La Rosa, Josep Lluis. Universidad de Girona; EspañaFil: Hormazábal, Nicolás. Universidad de Girona; EspañaFil: Aciar, Silvana Vanesa. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Lopardo, Gabriel Alejandro. Universidad de Girona; EspañaFil: Trias, Albert. Universidad de Girona; EspañaFil: Montaner, Miquel. No especifíca

Alcohol and educational inequalities : hazardous drinking prevalence and all-cause mortality by hazardous drinking group in people aged 50 and older in Europe

The SHARE data collection has been funded by the European Commission through FP5 [QLK6-CT-2001-00360], FP6 [SHARE-I3: RII-CT-2006-062193, COMPARE: CIT5-CT-2005-028857, SHARELIFE: CIT4-CT-2006-028812], FP7 [SHARE-PREP: GA N°211909, SHARE-LEAP: GA N°227822, SHARE M4: GA N°261982] and Horizon 2020 [SHARE-DEV3: GA N°676536, SERISS: GA N°654221] and by DG Employment, Social Affairs & Inclusion. Additional funding from the German Ministry of Education and Research, the Max Planck Society for the Advancement of Science, the U.S. National Institute on Aging [U01_AG09740-13S2, P01_AG005842, P01_AG08291, P30_AG12815, R21_AG025169, Y1-AG-4553-01, IAG_BSR06-11, OGHA_04-064, HHSN271201300071C] and from various national funding sources is gratefully acknowledged.Background: We examined educational inequalities in hazardous drinking prevalence among individuals aged 50 or more in 14 European countries, and explored educational inequalities in mortality in hazardous drinkers in European regions. Methods: We analyzed data from waves 4, 5 and 6 of the Survey of Health Ageing and Retirement in Europe (SHARE). We estimated age-standardized hazardous drinking prevalence, and prevalence ratios (PR) of hazardous drinking by country and educational level using Poisson regression models with robust variance. We estimated the relative index of inequality (RII) for all-cause mortality among hazardous drinkers and non-hazardous drinkers using Cox proportional hazards regression models and for each region (North, South, East and West). Results: In men, educational inequalities in hazardous drinking were not observed (PRmedium = 1.09 [95%CI: 0.98-1.21] and PRhigh = 0.99 [95%CI: 0.88-1.10], ref. low), while in they were observed in women, having the highest hazardous drinking prevalence in the highest educational levels (PRmedium = 1.28 [95%CI: 1.15-1.42] and PRhigh = 1.53 [95%CI: 1.36 1.72]). Overall, the Relative Index of Inequality (RII) in all-cause mortality among hazardous drinkers was 1.12 [95%CI: 1.03-1.22] among men and 1.10 [95%CI: 0.97-1.25] among women. Educational inequalities among hazardous drinkers were observed in Eastern Europe for both men (RIIhazardous = 1.21 [95%CI: 1.01-1.45]) and women (RIIhazardous = 1.46 [95%CI: 1.13-1.87]). Educational inequalities in mortality among non-hazardous drinkers were observed in Southern, Western and Eastern Europe among men, and in Eastern Europe among women. Conclusions: Higher educational attainment is positively associated with hazardous drinking prevalence among women, but not among men in most of the analyzed European countries. Clear educational inequalities in mortality among hazardous drinkers were only observed in Eastern Europe. Further research on the associations between alcohol use and inequalities in all-cause mortality in different regions is needed

Alcohol and educational inequalities:Hazardous drinking prevalence and all-cause mortality by hazardous drinking group in people aged 50 and older in Europe

Background: We examined educational inequalities in hazardous drinking prevalence among individuals aged 50 or more in 14 European countries, and explored educational inequalities in mortality in hazardous drinkers in European regions. Methods: We analyzed data from waves 4, 5 and 6 of the Survey of Health Ageing and Retirement in Europe (SHARE). We estimated age-standardized hazardous drinking prevalence, and prevalence ratios (PR) of hazardous drinking by country and educational level using Poisson regression models with robust variance. We estimated the relative index of inequality (RII) for all-cause mortality among hazardous drinkers and non-hazardous drinkers using Cox proportional hazards regression models and for each region (North, South, East and West). Results: In men, educational inequalities in hazardous drinking were not observed (PRmedium = 1.09 [95%CI: 0.98–1.21] and PRhigh = 0.99 [95%CI: 0.88–1.10], ref. low), while in they were observed in women, having the highest hazardous drinking prevalence in the highest educational levels (PRmedium = 1.28 [95%CI: 1.15–1.42] and PRhigh = 1.53 [95%CI: 1.36–1.72]). Overall, the Relative Index of Inequality (RII) in all-cause mortality among hazardous drinkers was 1.12 [95%CI: 1.03–1.22] among men and 1.10 [95%CI: 0.97–1.25] among women. Educational inequalities among hazardous drinkers were observed in Eastern Europe for both men (RIIhazardous = 1.21 [95%CI: 1.01–1.45]) and women (RIIhazardous = 1.46 [95%CI: 1.13–1.87]). Educational inequalities in mortality among non-hazardous drinkers were observed in Southern, Western and Eastern Europe among men, and in Eastern Europe among women. Conclusions: Higher educational attainment is positively associated with hazardous drinking prevalence among women, but not among men in most of the analyzed European countries. Clear educational inequalities in mortality among hazardous drinkers were only observed in Eastern Europe. Further research on the associations between alcohol use and inequalities in all-cause mortality in different regions is needed

Muscle-on-a-chip with an on-site multiplexed biosensing system for in situ monitoring of secreted IL-6 and TNF-α

Despite the increasing number of organs-on-a-chip that have been developed in the past decade, limited efforts have been made to integrate a sensing system for in situ continual measurements of biomarkers from three-dimensional (3D) tissues. Here, we present a custom-made integrated platform for muscle cell stimulation under fluidic conditions connected with a multiplexed high-sensitivity electrochemical sensing system for in situ monitoring. To demonstrate this, we use our system to measure the release levels and release time of interleukin 6 and tumor necrosis factor alpha in vitro by 3D muscle microtissue under electrical and biological stimulations. Our experimental design has enabled us to perform multiple time point measurements using functionalized screen-printed gold electrodes with sensitivity in the ng mL−1 range. This affordable setup is uniquely suited for monitoring factors released by 3D single cell types upon external stimulation for metabolic studies

Microphysiological sensing platform for an in-situ detection of tissue-secreted cytokines

Understanding the protein-secretion dynamics from single, specific tissues is critical toward the advancement of disease detection and treatments. However, such secretion dynamics remain difficult to measure in vivo due to the uncontrolled contributions from other tissue populations. Here, we describe an integrated platform designed for the reliable, near real-time measurements of cytokines secreted from an in vitro single-tissue model. In our setup, we grow 3D biomimetic tissues to discretize cytokine source, and we separate them from a magnetic microbead-based biosensing system using a Transwell insert. This design integrates physiochemically controlled biological activity, high-sensitivity protein detection (LOD < 20 pg mL−1), and rapid protein diffusion to enable non-invasive, near real-time measurements. To showcase the specificity and sensitivity of the system, we use our setup to probe the inflammatory process related to the protein Interleukine 6 (IL-6) and to the Tumor Necrosis Factor (TNF-α). We show that our setup can monitor the time-dependence profile of IL-6 and TNF-α secretion that results from the electrical and chemical stimulation of 3D skeletal muscle tissues. We demonstrate a novel and affordable methodology for discretizing the secretion kinetics of specific tissues for advancing metabolic-disorder studies and drug-screening applications

Clinical Outcomes of Severe COVID-19 Patients Admitted to an Intermediate Respiratory Care Unit

Introduction: Many severe COVID-19 patients require respiratory support and monitoring. An intermediate respiratory care unit (IMCU) may be a valuable element for optimizing patient care and limited health-care resources management. We aim to assess the clinical outcomes of severe COVID-19 patients admitted to an IMCU. Methods: Observational, retrospective study including patients admitted to the IMCU due to COVID-19 pneumonia during the months of March and April 2020. Patients were stratified based on their requirement of transfer to the intensive care unit (ICU) and on survival status at the end of follow-up. A multivariable Cox proportional hazards method was used to assess risk factors associated with mortality. Results: A total of 253 patients were included. Of them, 68% were male and median age was 65 years (IQR 18 years). Ninety-two patients (36.4%) required ICU transfer. Patients transferred to the ICU had a higher mortality rate (44.6 vs. 24.2%; p < 0.001). Multivariable proportional hazards model showed that age ≥65 years (HR 4.14; 95%CI 2.31-7.42; p < 0.001); chronic respiratory conditions (HR 2.34; 95%CI 1.38-3.99; p = 0.002) and chronic kidney disease (HR 2.96; 95%CI 1.61-5.43; p < 0.001) were independently associated with mortality. High-dose systemic corticosteroids followed by progressive dose tapering showed a lower risk of death (HR 0.15; 95%CI 0.06-0.40; p < 0.001). Conclusions: IMCU may be a useful tool for the multidisciplinary management of severe COVID-19 patients requiring respiratory support and non-invasive monitoring, therefore reducing ICU burden. Older age and chronic respiratory or renal conditions are associated with worse clinical outcomes, while treatment with systemic corticosteroids may have a protective effect on mortality