Algunas Propiedades de Consistencia de las Familias de Operadores de Agregación

Diversos estudios se han centrado en analizar amplia y profundamente distintas propiedades de los operadores de agregación. Sin embargo, no ha ocurrido lo mismo en el estudio de propiedades relativas a las Familias de Operadores de Agregación. ¿Debiera haber una relación entre los miembros de una familia de operadores de agregación?,¿es posible agregar n elementos de una base de datos con operadores de agregación de menor dimensión?, ¿debería haber algún tipo de consistencia interna en una familia de operadores de agregación?. En este trabajo se analiza la estabilidad para una familia de operadores de agregación, a fin de asegurar la consistencia entre operadores de una misma familia, y a través de esto, la robustez del proceso de agregación. La propiedad de Estabilidad que aquí se propone,intenta forzar a que una familia de operadores de agregación tenga una definición estable/contínua en términos de robustez de los resultados, para lo cual se condiciona que la agregación de n elementos no debe ser muy distinta a la de n − 1 elementos, cuando un ítem es el valor agregado de los otros. Se presentan algunas definiciones y resultados siguiendo esta idea para distintos niveles de estabilidad y dos tipos de estructuras en un proceso de agregación lineal

Charged Current b → cτ̅ν_τ Anomalies in a General W' Boson Scenario

Very recent experimental information obtained from the Belle experiment, along with that accumulated by the BABAR and LHCb experiments, has shown the existence of anomalies in the ratios R(D) and R(D∗) associated with the charged-current transition b → cτ̅ν_τ . Although the Belle measurements are in agreement with the standard model (SM) predictions, the new experimental world averages still exhibit a tension. In addition, the D∗ longitudinal polarization FL(D∗) related with the channel B → D∗τ ̄ντ observed by the Belle Collaboration and the ratio R(J/ψ) measured by the LHCb Collaboration also show discrepancies with their corresponding SM estimations. We present a model-independent study based on the most general effective Lagrangian that yields a tree-level effective contribution to the transition b → cτ ̄ντ induced by a general W ′ boson. Instead of considering any specific new physics (NP) realization, we perform an analysis by considering all of the different chiral charges to the charm-bottom and τ -ντ nteraction terms with a charged W ′ boson that explain the anomalies. We present a phenomenological study of parameter space allowed by the new experimental b → cτ ̄ντ data and ith the mono-tau signature pp → τhX + MET at the LHC. For comparison we include some of the W ′ boson NP realizations hat have already been studied in the literature

The impact of strong recombination on temperature determination in planetary nebulae

The long-standing difference in chemical abundances determined from optical recombination lines and collisionally excited lines raises questions about our understanding of atomic physics, as well as the assumptions made when determining physical conditions and chemical abundances in astrophysical nebulae. Here, we study the recombination contribution of [O III] 4363 and the validity of the line ratio [O III] 4363/4959 as a temperature diagnostic in planetary nebulae with a high abundance discrepancy. We derive a fit for the recombination coefficient of [O III] 4363 that takes into account the radiative and dielectronic recombinations, for electron temperatures from 200 to 30,000 K. We estimate the recombination contribution of [O III] 4363 for the planetary nebulae Abell 46 and NGC 6778 by subtracting the collisional contribution from the total observed flux. We find that the spatial distribution for the estimated recombination contribution in [O III] 4363 follows that of the O II 4649 recombination line, both peaking in the central regions of the nebula, especially in the case of Abell 46 which has a much higher abundance discrepancy. The estimated recombination contribution reaches up to 70% and 40% of the total [O III] 4363 observed flux, for Abell 46 and NGC 6778, respectively.Comment: Accepted in MNRAS Letter

Adipogenesis Regulation and Endocrine Disruptors: Emerging Insights in Obesity

Indexación: Scopus.Endocrine disruptors (EDs) are defined as environmental pollutants capable of interfering with the functioning of the hormonal system. They are environmentally distributed as synthetic fertilizers, electronic waste, and several food additives that are part of the food chain. They can be considered as obesogenic compounds since they have the capacity to influence cellular events related to adipose tissue, altering lipid metabolism and adipogenesis processes. This review will present the latest scientific evidence of different EDs such as persistent organic pollutants (POPs), heavy metals, "nonpersistent" phenolic compounds, triclosan, polybrominated diphenyl ethers (PBDEs), and smoke-derived compounds (benzo -alpha-pyrene) and their influence on the differentiation processes towards adipocytes in both in vitro and in vivo models.https://www.hindawi.com/journals/bmri/2020/7453786/#copyrigh

Antimicrobial and antibiofilm capacity of chitosan nanoparticles against wild type strain of pseudomonas sp. Isolated from milk of cows diagnosed with bovine mastitis

Indexación; Scopus.Bovine mastitis (BM) is the most prevalent bacterial infection in the livestock sector, affecting the dairy industry greatly. The prevention and treatment of this disease is mainly made via antibiotics, but the increasing antimicrobial resistance of pathogens has affected the efficiency of conventional drugs. Pseudomonas sp. is one of the pathogens involved in this infection. The therapeutic rate of cure for this environmental mastitis-causing pathogen is practically zero, regardless of treatment. Biofilm formation has been one of the main virulence mechanisms of Pseudomonas hence presenting resistance to antibiotic therapy. We have manufactured chitosan nanoparticles (NQo) with tripolyphosphate (TPP) using ionotropic gelation. These NQo were confronted against a Pseudomonas sp. strain isolated from milk samples of cows diagnosed with BM, to evaluate their antimicrobial and antibiofilm capacity. The NQo showed great antibacterial effect in the minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC) and disk diffusion assays. Using sub lethal concentrations, NQo were tested for inhibition of biofilm formation. The results show that the nanoparticles exhibited biofilm inhibition and were capable of eradicate pre-existing mature biofilm. These findings indicate that the NQo could act as a potential alternative to antibiotic treatment of BM. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/2079-6382/9/9/55

Long-Standing International Cooperation in Parasitology Research: A Summary of 35 Years of Activities in the Bolivian Chaco

The Bolivian Chaco is a semiarid region with a low population density, situated in the southeast part of the Plurinational State of Bolivia. Here, despite the improvements of the last 15 years, poverty remains high in rural areas, where social vulnerability is widespread. The Guaraní ethnic group often lives in isolated communities with a low standard of hygiene and sanitation. This epidemiological scenario favors the spread of transmissible diseases, including several parasitic infections belonging to the neglected tropical diseases (NTDs) group. In this area, a long-standing research activity, built upon the synergism between local and foreign institutions, has been established since the late 1980s and helps to fill in the knowledge gap about the epidemiology dynamics of soil-transmitted helminths, vector-borne parasites, and other parasitic diseases. A 35-year history of cooperation programs in parasitology research has contributed to informing local health authorities of the NTD burden in the Bolivian Chaco and, ultimately, supports local healthcare providers in the management of parasitic diseases

Multi-Messenger Astronomy with Extremely Large Telescopes

The field of time-domain astrophysics has entered the era of Multi-messenger Astronomy (MMA). One key science goal for the next decade (and beyond) will be to characterize gravitational wave (GW) and neutrino sources using the next generation of Extremely Large Telescopes (ELTs). These studies will have a broad impact across astrophysics, informing our knowledge of the production and enrichment history of the heaviest chemical elements, constrain the dense matter equation of state, provide independent constraints on cosmology, increase our understanding of particle acceleration in shocks and jets, and study the lives of black holes in the universe. Future GW detectors will greatly improve their sensitivity during the coming decade, as will near-infrared telescopes capable of independently finding kilonovae from neutron star mergers. However, the electromagnetic counterparts to high-frequency (LIGO/Virgo band) GW sources will be distant and faint and thus demand ELT capabilities for characterization. ELTs will be important and necessary contributors to an advanced and complete multi-messenger network.Comment: White paper submitted to the Astro2020 Decadal Surve

Immunohistochemical assessment of Pax8 expression during pancreatic islet development and in human neuroendocrine tumors

The paired box transcription factor Pax8 is critical for development of the eye, thyroid gland as well as the urinary and reproductive organs. In adult, Pax8 overexpression is associated with kidney, ovarian and thyroid tumors and has emerged as a specific marker for these cancers. Recently, Pax8 expression was also reported in human pancreatic islets and in neuroendocrine tumors, identifying Pax8 as a novel member of the Pax family expressed in the pancreas. Herein, we sought to provide a comprehensive analysis of Pax8 expression during pancreogenesis and in adult islets. Immunohistochemical analysis using the most employed Pax8 polyclonal antibody revealed strong nuclear staining in the developing mouse pancreas and in mature human and mouse islets. Astonishingly, Pax8 mRNA in mouse islets was undetectable while human islets exhibited low levels. These discrepancies raised the possibility of antibody cross-reactivity. This premise was confirmed by demonstrating that the polyclonal Pax8 antibody also recognized the islet-enriched Pax6 protein both by Western blotting and immunohistochemistry. Thus, in islets polyclonal Pax8 staining corresponds mainly to Pax6. In order to circumvent this caveat, a novel Pax8 monoclonal antibody was used to re-evaluate whether Pax8 was indeed expressed in islets. Surprisingly, Pax8 was not detected in neither the developing pancreas or in mature islets. Reappraisal of pancreatic neuroendocrine tumors using this Pax8 monoclonal antibody exhibited no immunostaining as compared to the Pax8 polyclonal antibody. In conclusion, Pax8 is not expressed in the pancreas and cast doubts on the value of Pax8 as a pancreatic neuroendocrine tumor marker

Indicated school-based intervention to improve depressive symptoms among at risk Chilean adolescents: a randomized controlled trial

Background: Depression is a disabling condition affecting people of all ages, but generally starting during adolescence. Schools seem to be an excellent setting where preventive interventions may be delivered. This study aimed to test the effectiveness of an indicated school-based intervention to reduce depressive symptoms among at-risk adolescents from low-income families. Methods: A two-arm, parallel, randomized controlled trial was conducted in 11 secondary schools in vulnerable socioeconomic areas in Santiago, Chile. High-risk students in year 10 (2° Medio) were invited to a baseline assessment (n = 1048). Those who scored ≥10 (boys) and ≥15 (girls) in the BDI-II were invited to the trial (n = 376). A total of 342 students consented and were randomly allocated into an intervention or a control arm in a ratio of 2:1. The intervention consisted of 8 group sessions of 45 min each, based on cognitive-behavioural models and delivered by two trained psychologists in the schools. Primary (BDI-II) and secondary outcomes (measures of anxiety, automatic thoughts and problem-solving skills) were administered before and at 3 months post intervention. The primary outcome was the recovery rate, defined as the proportion of participants who scored in the BDI-II <10 (among boys) and <15 (among girls) at 3 months after completing the intervention. Results: There were 229 participants in the intervention group and 113 in the control group. At 3-month follow-up 81.4 % in the intervention and 81.7 % in the control group provided outcome data. The recovery rate was 10 % higher in the intervention (50.3 %) than in the control (40.2 %) group; with an adjusted OR = 1.62 (95 % CI: 0.95 to 2.77) (p = 0.08). No difference between groups was found in any of the secondary outcomes. Secondary analyses revealed an interaction between group and baseline BDI-II score. Conclusions: We found no clear evidence of the effectiveness of a brief, indicated school-based intervention based on cognitive-behavioural models on reducing depressive symptoms among Chilean adolescents from low-income families. More research is needed in order to find better solutions to prevent depression among adolescents

Asociación entre bajo peso al nacer y malformaciones congénitas

Introducción: Las anomalías congénitas son defectos estructurales o funcionales durante la vida intrauterina. Es poco conocida la relación existente entre el bajo peso al nacer y la predisposición a una anomalía congénita. Objetivo: Evaluar la asociación entre el bajo peso al nacer y la manifestación de anomalías congénitas en neonatos. Métodos: Se realizó un estudio transversal. La población de estudio fueron madres que dieron a luz a neonatos en un hospital de Asunción, Paraguay, en 2018. Se crearon fichas de recolección de datos con las características maternas y neonatales. La variable desenlace fue malformaciones congénitas al nacimiento. La variable exposición fue bajo peso al nacer, definido como el reporte clínico de peso menor a 2 500 gramos en un neonato. Resultados: De 225 mujeres, se encontró que el 26,7 % presentó infecciones de transmisión maternoneonatal (60/165); 102 (45,3 %) fueron prematuros y 79 (35,1 %) presentaron malformaciones congénitas. Se evidenció asociación positiva entre antecedente de bajo peso al nacer y malformaciones congénitas (RP= 2,32; IC 95 %: 1,68-3,20). Conclusiones: Se evidencia una asociación positiva entre el antecedente de bajo peso al nacer y la presencia de malformaciones congénitas.Campus Lima Centr