Partially observable Markov decision processes with partially observable random discount factors

summary:This paper deals with a class of partially observable discounted Markov decision processes defined on Borel state and action spaces, under unbounded one-stage cost. The discount rate is a stochastic process evolving according to a difference equation, which is also assumed to be partially observable. Introducing a suitable control model and filtering processes, we prove the existence of optimal control policies. In addition, we illustrate our results in a class of GI/GI/1 queueing systems where we obtain explicitly the corresponding optimality equation and the filtering process

Sub-critical long-term operation of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system

The aim of this study was to evaluate the long-term performance of hollow-fibre (HF) membranes used to treat urban wastewater in a submerged anaerobic MBR when operating sub-critically. To this end, a demonstration plant with two industrial scale HF ultrafiltration membrane modules was operated under different conditions. The main factor affecting membrane performance was the concentration of mixed liquor total solids (MLTS). The reversible fouling rate remained low even when MLTS levels (about 25 g L−1) in the membrane tank were high. No chemical cleaning was conducted whilst operating the plant for more than one year because no irreversible fouling problems were detected. The almost complete absence of irreversible fouling was mainly attributed to: operating at sub-critical filtration conditions; establishing a proper membrane operating mode; and to the characteristics of the anaerobic environment. No chemical precipitation problems were observed in the membranes due to the relatively low operating pH (always below 7) of the sludge. The biogas sparging encouraged high levels of dissolved CO2 in the sludge, resulting in pH levels below 7 and alkalinity values around 600 mg CaCO3 L−1.This research work has been supported by the Spanish Research Foundation (CICYT Projects CTM2008-06809-C02-01 and CTM2008-06809-C02-02, and MICINN FPI Grant BES-2009-023712) and Generalitat Valenciana (Projects GVA-ACOMP2010/130 and GVA-ACOMP2011/1182), which are gratefully acknowledged.Robles Martínez, Á.; Ruano García, MV.; Ribes Bertomeu, J.; Ferrer, J. (2012). Sub-critical long-term operation of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system. Separation and Purification Technology. 100:88-96. https://doi.org/10.1016/j.seppur.2012.09.010S889610

An approach for dynamic analysis of stationary cracks using XFEM

A numerical implementation of the eXtended Finite Element Method (XFEM) is presented. The proposed approach solves the system of discrete equations using an explicit integration scheme and it is capable of addressing dynamic and static fracture mechanics problems. Special attention to the mass matrix construction is required in order to avoid instability issues such a null stable time increment. Hence, different mass lumping strategies are adopted for enriched elements. The in-house implementation of this approach, so-called X in-house FE platform called MULE. Numerical tests demonstrate that the proposed approach is able to provide an accurate calculation of static and dynamic stress intensity factors (SIFs) for different geometries and loading scenarios. Finally, in order to extend our point of view, an experimental analysis of a 10◦ off-axis carbon fibre laminate is carried out using Digital Image Correlation (DIC)

Randomized Clinical Trials of obesity treatments in Mexican population. Systematic Review and Meta-Analysis

Background: Mexicans and Mexican Americans share similar culture, genetic background, and predisposition for obesity and diabetes. Randomized clinical trials (RCT) assessing obesity treatments (ObT) are reliable to assess efficacy. To date, there is no systematic review to investigate ObT tested by RCT in Mexican adults. Methods: We conducted systematic searches in Pubmed, Scopus, and Web of Science to retrieve ObT RCT from 1990 to 2019. The ObT included alternative medicine, pharmacological, nutritional, behavioral, and surgical interventions. The analyzed RCT were at least three months of duration, and reported: BMI, weight, waist circumference, triglycerides, glucose and blood pressure. Results: We found 634 entries; after removal of duplicates and exclusions based on eligibility criteria, we analyzed 43 and 2 multinational-collaborative studies. Most of the national studies had small sample sizes, and did not have replications from other studies. The nutrition/behavioral interventions were difficult to blind, and most studies had medium to high risk of bias. Random effects meta-analysis of nutritional/behavioral interventions and medications showed effects on BMI, waist circumference, and blood pressure. Simple measures like plain water instead of sweet beverages decreased triglycerides and systolic blood pressure. Participants with obesity and hypertension had beneficial effects with antioxidants, and the treatment with insulin increased weight in those with T2D. Conclusions: The RCT’s in Mexico reported effects on metabolic components despite small sample sizes and lack of replication. In the future we should analyze ObT in population living on the U.S.-Mexico border; therefore, bi-national collaboration is desirable to disentangle cultural effects on ObT response

Prevalence and factors associated with supportive care needs among newly diagnosed Mexican breast cancer patients

PURPOSE: Mexican breast cancer patients are generally diagnosed in advanced stages of the disease and often experience delays in cancer treatment delivery. Currently, little is known about these patients' psychological care needs. This study assessed levels and correlates of supportive care needs of Mexican breast cancer patients around the time of cancer diagnosis. METHODS: One hundred seventy-three newly diagnosed Mexican breast cancer patients participated in the study. Supportive care needs, anxiety, depression, and patients' sociodemographic and clinical characteristics were assessed. Multiple regression analyses were used to examine factors associated with care needs. RESULTS: Up to 44% of patients showed unmet care needs. Health system/information needs were the most prevalent (68%), while physical/daily living needs the least (19%). Level of depressive symptoms was most consistently related to care needs. Patients with higher levels of depressive symptoms had higher psychological (β = 0.38), physical/daily living (β = 0.43), patient care/support (β = 0.17), and additional unmet care needs (β = 0.30), than patients with lower levels of depressive symptoms. CONCLUSIONS: This study suggests that mainly health system/information needs arise at the time of cancer diagnosis among Mexican breast cancer patients. Patients suffering high levels of depressive symptoms reported the highest levels of unmet needs. Future studies should be conducted to elucidate the care needs throughout the disease trajectory, as such information can inform health care professionals and policy makers and lead to improvements in the organization and provision of health care services for Mexican breast cancer patients

Multimodal Functional Network Connectivity: An EEG-fMRI Fusion in Network Space

EEG and fMRI recordings measure the functional activity of multiple coherent networks distributed in the cerebral cortex. Identifying network interaction from the complementary neuroelectric and hemodynamic signals may help to explain the complex relationships between different brain regions. In this paper, multimodal functional network connectivity (mFNC) is proposed for the fusion of EEG and fMRI in network space. First, functional networks (FNs) are extracted using spatial independent component analysis (ICA) in each modality separately. Then the interactions among FNs in each modality are explored by Granger causality analysis (GCA). Finally, fMRI FNs are matched to EEG FNs in the spatial domain using network-based source imaging (NESOI). Investigations of both synthetic and real data demonstrate that mFNC has the potential to reveal the underlying neural networks of each modality separately and in their combination. With mFNC, comprehensive relationships among FNs might be unveiled for the deep exploration of neural activities and metabolic responses in a specific task or neurological state

Risk factors for mortality caused by pseudomonas aeruginosa infection in hospitalized patients with oncologic diagnosis in three cities of Colombia

Pseudomonas aeruginosa es una bacteria oportunista Gram negativa particularmente eficiente en la adquisición de mecanismos de resistencia y de alta prevalencia en infecciones nosocomiales en pacientes oncológicos. Objetivo: identificar los factores de riesgo para mortalidad en pacientes oncológicos con aislamiento de P. aeruginosa. Metodología: estudio descriptivo, la población de estudio fueron los casos reportados con aislamiento de P. aeruginosa en el servicio de hospitalización de Oncólogos de Occidente en Pereira, Armenia y Manizales durante el año 2015. Se realizaron análisis univariados y multivariados; la supervivencia se estableció según el método de Kaplan-Meier. Se estableció un valor de p <0.05. Se usó el software STATA. Se tuvo aval de bioética de la Universidad Tecnológica de Pereira. Resultados: se estudió 41 casos confirmados de cultivos positivos de P. aeruginosa. El sexo masculino (46.3%), anemia (46.3%), neutropenia febril (41%), trombocitopenia (29.3%) y haber sido hospitalizado en la unidad de cuidados intensivos (29.3%) fueron asociados estadísticamente con mayor mortalidad (p=0.019); con estos resultados se diseñó una escala de riesgo (alfa de Cronbach =0.72). Los pacientes con cuatro de estas exposiciones mostraron mayor riesgo de mortalidad al egreso hospitalario con una sensibilidad del 68% y especificidad del 90%. La P. aeruginosa presentó resistencia a cefepime (36.6%) y a aztreonam (34.1%), mientras que la letalidad global fue del 26.8%. Conclusión: El sexo masculino, la coexistencia de anemia, trombocitopenia, y neutropenia febril, así como la estancia en la unidad de cuidados intensivos aumentan la mortalidad en los pacientes oncológicos infectados con P. aeruginosa.Pseudomonas aeruginosa is a Gram-negative and rod-shape opportunistic bacterium that is particularly efficient in the acquisition of resistance mechanisms and its high prevalence in nosocomial infections in cancer patients. Objective: To identify risk factors for mortality in cancer patients with P. aeruginosa infection. Methodology: A descriptive study was carried out in patients with P. aeruginosa infection during the hospitalization service of “Oncólogos de Occidente” in Pereira, Armenia and Manizales during 2015. Univariate and multivariate analyzes were performed. The survival analysis was established according to the Kaplan-Meier method. A value of p<0.05 was established for it. The analyses were examined with the STATA software. This study was endorsed by the bioethics committee of the “Universidad Tecnológica de Pereira”. Results: Fourty-one patients with positive culture for P. aeruginosa were studied. Males (46.3%), anemia (46.3%), febrile neutropenia (41%), thrombocytopenia (29.3%) and previous hospitalization in an intensive care unit (29.3%) were associated with higher mortality risk (p = 0.019); a risk scale was designed with these factors (Cronbach´s alpha = 0.72). Patients who presented four of these exposures were at higher risk of mortality with a sensitivity of 68% and specificity of 90% at the moment of discharge. P. aeruginosa showed 36.6% of resistance to cefepime, 34.1% to aztreonam, the mortality rate was 26.8%. Conclusion: Male sex, anemia, thrombocytopenia, febrile neutropenia and previous hospitalization in an intensive care unit increase the mortality rate in patients with cancer who were infected by P. aeruginosa.

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30