1,643 research outputs found
A machine learning based Distributed Congestion Control Protocol for multi-hop wireless networks
The application areas of multi-hop wireless networks are expected to experience sustained growth in the next years. This growth will be further supported by the current possibility of providing low-cost communication capabilities to any device. One of the main issues to consider with this type of networks is congestion control, that is, avoiding an excessive volume of data traffic that could lead to a loss of performance. In this work, a distributed congestion control mechanism is proposed for generic multi-hop networks. Different categories of data traffic are taken into account, each of them with different quality of service requirements. The mechanism is based on machine learning techniques, specifically, the CatBoost algorithm that uses gradient boosting on decision trees. The obtained decision trees are used to predict whether the packets to be transmitted over the network will reach their destination on time or not. This prediction will be made based on the network load state, which will be quantified by means of two parameters: the utilization factor of the different transmission channels, and the occupancy of the buffers of the network nodes. To make the values of these parameters available to all nodes in the network, an appropriate dissemination protocol has also been designed. Besides, a method to assign different transmission priorities to each traffic category, based on the estimation of the network resources required at any time, has also been included. The complete system has been implemented and evaluated through simulations, which show the correct functionality and the improvements obtained in terms of packet delivery ratio, network transit time, and traffic differentiation.Peer ReviewedPostprint (published version
Woody debris trapping phenomena evaluation in bridge piers: A Bayesian perspective
l artículo propone el uso de una red bayesiana y analiza sus ventajas y desventajas para realizar el diagnóstico y la propuesta de remediación en el caso de puentes sujetos a la acumulación de escombros de madera en la base de las pilas.A flood occurs when water and other materials such as woody debris overflow dry areas. If there is infrastructure present, woody fragments could be transported downstream and eventually trapped, leading to increments in the hydrodynamic forces over, say, a bridge. Moreover, local scour can be developed in the structure piers. The purpose of this research is to investigate the bridge pier scour phenomena induced by woody debris from a probabilistic point of view. A Non Parametric Bayesian Belief Network comprising seven nodes has consequently been developed. They are: water level, Froude number, blockage amount, drag force, scour depth, damage and overturning. Through both Monte Carlo Simulation and data from a real structure, the nodes’ non parametric probability distributions have been established, an area that has, to date, received very little attention in the literature. By combining the variables under study, it was possible to determine their interaction and dependencies, showing that the depth of the approaching flow is correlated with two nodes: damage and overturning. The results are useful for bridge managers willing to rank investments in maintenance actions within the industry, and to develop optimal risk based strategies for efficiently employing the scarce resources used to that end
Are Major Repeater Patients Addicted to Suicidal Behavior?
The literature provides support for the hypothesis that some major repeaters (individuals with \u3e=5 lifetime suicide attempts) are addicted to suicidal behavior (SB). This study explores whether major repeaters are addicted to SB or not using 7 criteria: tolerance (Criterion 1), withdrawal (Criterion 2), loss of control (Criterion 3), problems in quitting/cutting down (Criterion 4), much time spent using (Criterion 5), substantial reduction in activities (Criterion 6), and adverse physiological/physical consequences (Criterion 7). Total dependence on SB was indicated by the presence of 3 or more of the 7 criteria in the last 12 months. This cross-sectional study at Puerta de Hierro University Hospital (Madrid, Spain) recruited 118 suicide attempters including 8 major repeaters (7%, 8/118), who were all females. The association between each SB addiction criterion, physiological dependence and total dependence with major repeater status was tested for significance and for effect size with odds ratios (ORs) and their 95% confidence intervals. As hypothesized, major repeaters met significantly higher frequency of criteria for total dependence on SB, OR=62.9 (6.4-615). A backward stepwise logistic regression model was used to provide an OR between major repeater status and total dependence status corrected by confounding variables. Age, panic disorder without agoraphobia, borderline personality disorder, history of psychiatric inpatient admission, and total dependence on SB were introduced as independent variables with major repeater status as the dependent variable. The model selected total dependence and age as the remaining significant variables in the last step. Accordingly, major repeaters appear to be addicted to SB
SARS-CoV-2 en pediatría. Historia de una pandemia desde China hasta Colombia
Introduction: Coronavirus until 1930 were part of the viruses that only disturbed the animal niche. Severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) a type of coronavirus that causes coronavirus disease (COVID-19); In the last year it has become a concern for international public health due to the triggered pandemic, due to its high transmissibility and high mortality that it has caused. Objective: describe SARS-COV-2 infection in pediatrics with special emphasis on virological, epidemiological aspects, transmission mechanism, clinical manifestations, and expectations of treatment in pediatric age. Methods: A review of articles in Spanish and English was made, using valid terms, on the PubMed, ScienceDirect and Medline databases related to the disease. Articles with a publication period of no more than 5 years were considered. Results: The epidemiology, pathophysiology, clinical manifestations, complications, isolation and possibilities of treatment of SARS-CoV-2 in pediatric age are described. Conclusions: SARS-CoV-2 is highly contagious, the pediatric population has mostly mild clinical manifestations. The importance of an appropriate approach in this population is to avoid spreading to other ages of greater morbidity and mortality and possible associated complications.Introducción: Hasta 1930 los coronavirus eran parte de los virus que solo afectaban animales. El síndrome respiratorio agudo severo por Coronavirus 2 (SARS-CoV-2), es un tipo de coronavirus causante de la enfermedad por coronavirus (COVID-19), el cual se ha convertido en un importante problema para la salud pública mundial por la pandemia desencadenada y su alta transmisibilidad y mortalidad. Objetivo: Describir la infección por SARS-CoV-2 en pediatría realizando especial énfasis en aspecto virológicos, epidemiológicos, mecanismo de transmisión, manifestaciones clínicas y expectativas de tratamiento en la edad pediatría. Métodos: Se hizo una revisión de artículos en español e inglés, usando términos estandarizados, sobre las bases de datos PubMed, ScienceDirect y Medline relacionados con la enfermedad. Se tuvieron en cuenta artículos con periodo de publicación no mayor a 5 años. Resultados: Se describe la epidemiologia, fisiopatología, manifestaciones clínicas, complicaciones, aislamiento y posibilidades de tratamiento de SARS-CoV-2 en edad pediátrica Conclusiones: SARS-CoV-2 es altamente contagioso, la población pediátrica tiene en su mayoría manifestaciones clínicas moderadas y leves. La importancia del abordaje adecuado en esta población es evitar la propagación a personas con edades de mayor morbimortalidad y posibles complicaciones asociadas
Platelet Count in First Trimester of Pregnancy as a Predictor of Perinatal Outcome
AIM: To rule out maternal and pregnancy factors that may contribute to platelet count (PLT) changes in the first trimester of gestation and examine if there is any association between its levels and adverse perinatal outcome.METHODS: The study population included all patients from the first-trimester visit between 2013-2015 with pregnancy results. Linear multiple regression was constructed to rule out variables that may have a significant contribution to PLT. For each adverse outcome at birth, multiple logistic regression analysis was implemented to estimate the PLT effect.RESULTS: PLT was measured in 6092 patients. There was the significant contribution on PLT in the first trimester from maternal weight, the presence of rheumatologic disease, BHCG levels and MPV. There was a significant association between PLT and abnormal cardiotocography at delivery (OR 1.004; IC95% 1.001 to 1.007) and C-Section due to abnormal CTG (OR 1.005; IC95% 1.002 to 1.008). When adjusted for factors that interact with PLT there was also a significant association with pH at birth < 7.10 and gestational diabetes.CONCLUSIONS: Maternal and pregnancy factors can poorly predict relevant changes in PLT at the first trimester of gestation. PLT at first trimester of pregnancy might predict adverse perinatal outcome in combination with other markers
Results of a survey on peri-operative nutritional support in pancreatic and biliary surgery in Spain
Introduction: a survey on peri-operative nutritional support in pancreatic and biliary surgery among Spanish hospitals in 2007 showed that few surgical groups followed the 2006 ESPEN guidelines. Ten years later we sent a questionnaire to check the current situation. Methods: a questionnaire with 21 items sent to 38 centers, related to fasting time before and after surgery, nutritional screening use and type, time and type of peri-operative nutritional support, and number of procedures. Results: thirty-four institutions responded. The median number of pancreatic resections (head/total) was 29.5 (95 % CI: 23.0-35; range, 5-68) (total, 1002); of surgeries for biliary malignancies (non-pancreatic), 9.8 (95 % CI: 7.3-12.4; range, 2-30); and of main biliary resections for benign conditions, 10.4 (95 % CI: 7.6-13.3; range, 2-33). Before surgery, only 41.2 % of the sites used nutritional support (< 50 % used any nutritional screening procedure). The mean duration of preoperative fasting for solid foods was 9.3 h (range, 6-24 h); it was 6.6 h for liquids (range, 2-12). Following pancreatic surgery, 29.4 % tried to use early oral feeding, but 88.2 % of the surveyed teams used some nutritional support; 26.5 % of respondents used TPN in 100 % of cases. Different percentages of TPN and EN were used in the other centers. In malignant biliary surgery, 22.6 % used TPN always, and EN in 19.3 % of cases. Conclusions: TPN is the commonest nutrition approach after pancreatic head surgery. Only 29.4 % of the units used early oral feeding, and 32.3 % used EN; 22.6 % used TPN regularly after surgery for malignant biliary tumours. The 2006 ESPEN guideline recommendations are not regularly followed 12 years after their publication in our country
Women with psychotic episodes during pregnancy show increased markers of placental damage with Tenney-Parker changes
y. Psychosis is a hazardous and functionally
disruptive psychiatric condition which may affect
women in pregnancy, entailing negative consequences
for maternofetal well-being. The precise pathophysiological basis and consequences of a psychotic episode in
pregnancy remain to be further elucidated. The placenta
is a pivotal tissue with many functions in the gestational
period, critically influencing the fate and development of
pregnancy. Although detrimental alterations have been
observed in women undergoing severe psychiatric
disorders in pregnancy, there are little studies evaluating
the consequences of suffering from a psychotic episode
in the placental tissue In this work, we have evaluated
the histopathological consequences of a first episode of
psychosis in pregnancy (FE-PW; N=22) and compare
them with healthy pregnant women (HC-PW; N=20) by
using histological, immunohistochemical and gene
expression techniques. Our results define that the
placental tissue of FE-PW display an increase in the
number of placental villi, bridges, syncytial knots and
syncytial knots/villi. Besides, we have also observed an
enhanced gene and protein expression in FE-PW of the
hypoxic marker HIF-1α, together with the apoptotic
markers BAX and Bcl-2. To our knowledge, this is the
first study demonstrating significant histopathological
changes in the placenta of women suffering a new-onset
psychotic episode in pregnancy. Further studies should
be aimed at deepening the knowledge about the
pernicious effects of psychosis in the maternofetal
tissues, as well as the potential implications of these
alterations
Machine learning on difference image analysis: A comparison of methods for transient detection
We present a comparison of several Difference Image Analysis (DIA) techniques, in combination with Machine Learning (ML) algorithms, applied to the identification of optical transients associated to gravitational wave events. Each technique is assessed based on the scoring metrics of Precision, Recall, and their harmonic mean F1, measured on the DIA results as standalone techniques, and also in the results after the application of ML algorithms, on transient source injections over simulated and real data. These simulations cover a wide range of instrumental configurations, as well as a variety of scenarios of observation conditions, by exploring a multi dimensional set of relevant parameters, allowing us to extract general conclusions related to the identification of transient astrophysical events. The newest subtraction techniques, and particularly the methodology published in Zackay et al., (2016) are implemented on an Open Source Python package, named properimage, suitable for many other astronomical image analyses. This together, with the ML libraries we describe, provides an effective transient detection software pipeline. Here we study the effects of the different ML techniques, and the relative feature importances for classification of transient candidates, and propose an optimal combined strategy. This constitutes the basic elements of pipelines that could be applied in searches of electromagnetic counterparts to GW sources.Fil: Sánchez, Bruno Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Dominguez Romero, Mariano Javier de Leon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Lares Harbin Latorre, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Beroiz, Martin Isidro Ramon. University of Texas; Estados UnidosFil: Cabral, Juan Bautista. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Gurovich, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Quiñones, Cecilia. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Artola, Rodolfo Alfredo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Colazo, Carlos A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Schneiter, Ernesto Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Girardini, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Tornatore, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Nilo Castellón, José Luis. Universidad de La Serena; ChileFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Díaz, Mario Coma. University of Texas At Brownsville. Center for Gravitational Wave Astronomy; Estados Unido
Maternal, Perinatal and Neonatal Outcomes of Triplet Pregnancies According to Chorionicity: A Systematic Review of the Literature and Meta-Analysis
Triplet pregnancies are rare events that affect approximately 93 in 100,000 deliveries in the world, especially due to the increased use of assisted reproductive techniques and older maternal age. Triplet pregnancies are associated with a higher risk of fetal and maternal morbidity and mortality compared to twins and singletons. Chorionicity has been proposed as a major determinant of perinatal and maternal outcomes in triplet pregnancies, although further evidence is needed to clarify the extent and real influence of this factor. Thus, the aim of this study was to conduct a systematic review of the literature and a meta-analysis of the maternal and perinatal outcomes of triplet pregnancies, evaluating how chorionicity may influence these results. A total of 46 studies with 43,653 triplet pregnancies and 128,145 live births were included. Among the main results of our study, we found a broad spectrum of fetal and maternal complications, especially in the group of monochorionic and dichorionic pregnancies. Risk of admission to NICU, respiratory distress, sepsis, necrotizing enterocolitis, perinatal and intrauterine mortality were all found to be higher in non-TCTA pregnancies than in TCTA pregnancies. To date, our meta-analysis includes the largest population sample and number of studies conducted in this field, evaluating a wide variety of outcome measures. The heterogeneity and retrospective design of the studies included in our research represent the main limitations of this review. More evidence is needed to fully assess outcome measures that could not be studied in this review due to scarcity of publications or insufficient sample size
The Use of Prebiotics from Pregnancy and Its Complications: Health for Mother and Offspring—A Narrative Review
Pregnancy involves a metabolic reprogramming that includes changes in the gut microbiota
composition in women. Evidence shows that maternal dysbiosis is linked to neonatal dysbiosis, and
this factor can determine health status in adulthood. Although there is little literature available on
this topic, high heterogeneity is a limitation when examining nutritional interventions. Information
has been gathered to contrast the benefits of prebiotic usage, specifically in pregnancy, in its possible
complications and in newborns’ gut microbiota development. The objective pursued in this brief
narrative review is to provide a clear summary of relevant content when searching with regard to the
use of prebiotics in pregnancy, the effects in prenatal and postnatal periods, and to help in clinical
decision-making in pregnancy management and lactation. A search has found that the nutritional
status of the pregnant mother is key for the earliest microbial colonization in newborns, and thus
intervention programs from pregnancy could assure better outcomes in both the mother and offspring.
In this sense, prebiotics (administered to mothers who breastfeed or provided in formula milk) are
feasible and cost-effective elements that can prevent allergies, colic, and other maladies in newborn
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