Positive solutions for some indefinite nonlinear eigenvalue elliptic problems with Robin boundary conditions

We consider a nonlinear eigenvalue problem with indefinite weight under Robin boundary condition. We prove the existence and multiplicity of positive solutions. To this end, we carry out a detailed study of some linear eigenvalues problems and we use mainly bifurcation and sub-supersolution methods.Ministerio de Economía y CompetitividadFondo Nacional de Desarrollo Científico y Tecnológico (Comisión Nacional de Investigación Científica y Tecnológica) (Chile

Scale-free foraging by primates emerges from their interaction with a complex environment

Scale-free foraging patterns are widespread among animals. These may be the outcome of an optimal searching strategy to find scarce randomly distributed resources, but a less explored alternative is that this behaviour may result from the interaction of foraging animals with a particular distribution of resources. We introduce a simple foraging model where individuals follow mental maps and choose their displacements according to a maximum efficiency criterion, in a spatially disordered environment containing many trees with a heterogeneous size distribution. We show that a particular tree size frequency distribution induces non-Gaussian movement patterns with multiple spatial scales (L\'evy walks). These results are consistent with tree size variation and Spider monkey (Ateles geoffroyi) foraging patterns. We discuss the consequences that our results may have for the patterns of seed dispersal by foraging primates.Comment: 31 pages, 4 figures. To appear in Proc. Roy. Soc. B. Minor revision

Caracterización de pacientes con infarto miocárdico con elevación del ST complicados no trombolizados

Introduction: Acute coronary syndrome is the ultimate expression of coronary disease, early diagnosis and proper treatment help to reduce the incidence of fatal complications and mortality associated with it.Material and  methods: an observational, longitudinal and prospective study was conducted in the Intensive Care Unit of cardiology at  “Arnaldo Milián Castro" Clinical Surgical Hospital of Villa Clara from January 2007 to December 2009 in order to characterize patients with myocardial elevation acute myocardial ST segment complicated and not thrombolyzed.Results: electrical complications presented 45.05 % of the patients and cardiogenic shock 22; died 100% of those with mechanical complications and 86.36 % of those with cardiogenic shock.Discussion: in this study the electrical complications were the most common and the most lethal were mechanical, cardiogenic shock and ventricular fibrillation, mechanical were more frequent in females, all generally predominated in older and had a higher representation in acute myocardial infarction of the extensive right ventricle, overall mortality was high and was associated with female sex, advanced age and extensive and lateral previuos topography.Introducción: El síndrome coronario agudo es la máxima expresión de la enfermedad coronaria, su diagnóstico precoz y su tratamiento adecuado contribuyen a disminuir la incidencia de complicaciones letales y la mortalidad asociada al mismo.Material y método: se realizó un estudio observacional, longitudinal y prospectivo en la Unidad de Cuidados Intensivos Cardiológicos del Hospital Clínico Quirúrgico “Arnaldo Milián Castro” de la Ciudad de Santa Clara, Provincia de  Villa Clara, desde enero de 2007 hasta diciembre de 2009 con el propósito de caracterizar a los pacientes con  infarto miocárdico agudo con elevación del segmento ST complicado y no trombolizados.Resultados: presentaron complicaciones eléctricas el 45.05% de los pacientes y el choque cardiogénico 22; fallecieron el 100% de los que presentaron complicaciones mecánicas y el 86.36% de los que tenían choque cardiogénico.Discusión: en este estudio las complicaciones eléctricas fueron las más frecuentes y las más letales resultaron las mecánicas, el choque cardiogénico y la fibrilación ventricular; las mécanicas fueron más frecuentes en el sexo femenino; todas en general predominaron en la edad avanzada y tuvieron una mayor representacion en los infarto miocárdico agudo de ventrículo derecho y anterior extenso; la mortalidad general fue elevada y se relacionó con el sexo femenino, la edad avanzada y la topografía anterior extensa y lateral

Protocolos de bioseguridad para la atención odontológica durante la pandemia COVID-19 en países de América Latina

Los protocolos de bioseguridad son importantes para la protección del personal de salud. En odontología estas medidas ayudarán a cuidar la salud de médico y paciente. Sin embargo, en América Latina el riesgo de contagio por la pandemia, ha obligado a adoptar medidas más drásticas que deben respetarse cuidadosamente. Describir los protocolos de bioseguridad recomendados por los Ministerios de Salud en los países de Latinoamérica para la atención odontológica durante la pandemia. Se realizó una búsqueda detenida sobre protocolos de bioseguridad; publicadas con una antigüedad de 1 año y medio en la base de datos de cada Ministerio de Salud y en Google. Los artículos de investigación, la información se hallaba en el idioma español, inglés, francés y portugués, se utilizó el método de comparación para ejecutar la revisión. Fueron encontrados 52 protocolos concernientes a la atención odontológica y aplicando criterios de comparación se hallaron 17. Los protocolos que se identificaron coinciden en su mayoría con los recomendados por la OMS, protocolos clínicos, sustancias a usarse y dispositivos utilizados, asimismo en algunos países no se encontraron ningún tipo de protocolo, o simplemente se rigen a las normas generales impuestas a los servicios de salud

Púrpura de Schönlein-Henoch fulminante

A female patient of 51 years old with personal pathological precedent of bronchial asthma, hypertension and ulcerative colitis and infection by chikungunya virus for a month. She incomes with dark pasty diarrhea with mucus and blood, she evolved unfavorably with flaccid paraplegia and recticularis livedo, which became extensive purple; then phlyctena and generalized edema. She remained hypotensive with electrolyte imbalance and impairment of consciousness, complementaries were performed, she was transfused and underwent to hemodialysis; she evolved to coma and death. The pathological findings showed an adult, fulminant and deadly form of anaphylactoid purpura or Henoch-Schönlein. Mesangial proliferation with fushinofílicos mesangial deposits werefound corresponding to immunoglobulin A with immunofluorescence, leukocytoclastic vasculitis and necrotizing vasculitis of small vessels. Purple of Schönlein-Henoch is a peculiar form of vasculitis that tends to spontaneous healing and occasionally may have a fatal course or proceed to a chronic nephritis.Se trata de paciente femenina de 51 años, con antecedentes patológicos personales de asma bronquial, hipertensión arterial y colitis ulcerativa e infección por el virus de la chikungunya desde hacía un mes. Ingresó con diarreas pastosas oscuras con moco y sangre, evolucionó desfavorablemente con paraplejia flácida y livedo reticularis, que se transformó en púrpura extensa; posteriormente flictenas y edema generalizado. Se mantuvo hipotensa con desequilibrio hidroelectrolítico y deterioro del estado de conciencia, se le realizaron complementarios, fue transfundida y se le realizó hemodiálisis; evolucionó al coma y a la muerte. Los hallazgos anatomopatológicos mostraron una forma adulta, fulminante y mortal de púrpura anafilactoide o de Schönlein-Henoch. Se encontró proliferación mesangial con depósitos mesangiales fushinofílicos correspondientes a inmunoglobulina A con inmunofluorescencia, vasculitis leucocitoclástica y vasculitis necrotizante de pequeños vasos. La púrpura de Schönlein-Henoch es una forma peculiar de vasculitis que tiende a la curación espontánea y, ocasionalmente, puede tener un curso mortal o proseguir hacia una nefritis crónica

DarkCideS 1.0, a global database for bats in karsts and caves

Tanalgo, Krizler C., Tabora, John Aries G., de Oliveira, Hernani Fernandes Magalhães, Haelewaters, Danny, Beranek, Chad T., Otálora-Ardila, Aída, Bernard, Enrico, Gonçalves, Fernando, Eriksson, Alan, Donnelly, Melissa, González, Joel Monzón, Ramos, Humberto Fernández, Rivas, Alberto Clark, Webala, Paul W., Deleva, Stanimira, Dalhoumi, Ridha, Maula, Jaycelle, Lizarro, Dennis, Aguirre, Luis F., Bouillard, Nils, Quibod, Ma. Niña Regina M., Barros, Jennifer, Turcios-Casco, Manfredo Alejandro, Martínez, Marcio, Ordoñez-Mazier, Diego Iván, Orellana, José Alejandro Soler, Ordoñez-Trejo, Eduardo J., Ordoñez, Danny, Chornelia, Ada, Lu, Jian Mei, Xing, Chen, Baniya, Sanjeev, Muylaert, Renata L., Dias-Silva, Leonardo Henrique, Ruadreo, Nittaya, Hughes, Alice Catherine (2022): DarkCideS 1.0, a global database for bats in karsts and caves. Scientific Data 9 (1): 155, DOI: 10.1038/s41597-022-01234-4, URL: http://dx.doi.org/10.1038/s41597-022-01234-

Modeling complex metabolic reactions, ecological systems, and financial and legal networks with MIANN models based on Markov-Wiener node descriptors

[Abstract] The use of numerical parameters in Complex Network analysis is expanding to new fields of application. At a molecular level, we can use them to describe the molecular structure of chemical entities, protein interactions, or metabolic networks. However, the applications are not restricted to the world of molecules and can be extended to the study of macroscopic nonliving systems, organisms, or even legal or social networks. On the other hand, the development of the field of Artificial Intelligence has led to the formulation of computational algorithms whose design is based on the structure and functioning of networks of biological neurons. These algorithms, called Artificial Neural Networks (ANNs), can be useful for the study of complex networks, since the numerical parameters that encode information of the network (for example centralities/node descriptors) can be used as inputs for the ANNs. The Wiener index (W) is a graph invariant widely used in chemoinformatics to quantify the molecular structure of drugs and to study complex networks. In this work, we explore for the first time the possibility of using Markov chains to calculate analogues of node distance numbers/W to describe complex networks from the point of view of their nodes. These parameters are called Markov-Wiener node descriptors of order kth (Wk). Please, note that these descriptors are not related to Markov-Wiener stochastic processes. Here, we calculated the Wk(i) values for a very high number of nodes (>100,000) in more than 100 different complex networks using the software MI-NODES. These networks were grouped according to the field of application. Molecular networks include the Metabolic Reaction Networks (MRNs) of 40 different organisms. In addition, we analyzed other biological and legal and social networks. These include the Interaction Web Database Biological Networks (IWDBNs), with 75 food webs or ecological systems and the Spanish Financial Law Network (SFLN). The calculated Wk(i) values were used as inputs for different ANNs in order to discriminate correct node connectivity patterns from incorrect random patterns. The MIANN models obtained present good values of Sensitivity/Specificity (%): MRNs (78/78), IWDBNs (90/88), and SFLN (86/84). These preliminary results are very promising from the point of view of a first exploratory study and suggest that the use of these models could be extended to the high-throughput re-evaluation of connectivity in known complex networks (collation)

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years