Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4

Pulsating low-mass white dwarf (WD) stars are WDs with stellar masses between 0.30 and 0.45 M⊙ that show photometric variability due to gravity-mode pulsations. Within this mass range, they can harbour both a helium core and hybrid core, depending if the progenitor experienced helium-core burning during the pre-WD evolution. SDSS J115219.99+024814.4 is an eclipsing binary system where both components are low-mass WDs, with stellar masses of 0.362 ± 0.014 M⊙ and 0.325 ± 0.013 M⊙. In particular, the less-massive component is a pulsating star, showing at least three pulsation periods of ∼1314, ∼1069, and ∼582.9 s. This opens the way to use asteroseismology as a tool to uncover its inner chemical structure, in combination with the information obtained using the light-curve modelling of the eclipses. To this end, using binary evolutionary models leading to helium- and hybrid-core WDs, we compute adiabatic pulsations for ℓ = 1 and ℓ = 2 gravity modes with Gyre. We found that the pulsating component of the SDSS J115219.99+024814.4 system must have a hydrogen envelope thinner than the value obtained from binary evolution computations, independently of the inner composition. Finally, from our asteroseismological study, we find a best-fitting model characterized by Teff=10917 K, M = 0.338 M⊙, and MH = 10−6 M⊙ with the inner composition of a hybrid WD

Lupus eritematoso tumidus y leishmaniasis: A propósito de un caso

Pocas veces se tiene en cuenta que la Leishmaniasis (enfermedad producida por un protozoo) y otras enfermedades de clínica similar como el Lupus Eritematoso (enfermedad de origen autoinmune) pueden presentarse en forma concomitante. El presente trabajo reporta el caso de una paciente a la cual se le diagnosticó en un primer momento Lupus Eritematoso Tumidus (LET) y posteriormente, ante la remisión parcial frente al tratamiento específico y debido a la procedencia de zona endémica de la paciente, se sospechó y se detectó la concomitancia con Leishmaniasis Mucosa (LM). OBJETIVO: Presentar el caso de una paciente a la cual se realizó diagnóstico de LET y LM. DISEÑO: Reporte de Caso. MATERIAL Y MÉTODO: Mujer de 47 años de edad procedente de Embarcación (departamento. San Martín, Salta), presentó lesión infiltrativa, costrosa y ulcerada en la mucosa nasal, dolorosa, con bordes no definidos, y perforación septal con bordes infiltrados, eritematosos y cubiertos con costras serohematicas. El diagnóstico en un primer momento se realizó a través de examen histopatológico de biopsia de piel nasal tomada con sacabocados, que resultó positivo para LET, y también mediante serología anti-Ro, anti-La y anti-ADN, con resultados negativos. Frente al tratamiento con hidrocloroquina (200mg/día-30 días) hubo mejoría parcial. Ante la sospecha de una posible concomitancia con LM, se realizaron raspados y aspirados de borde de septum nasal para microscopía, PCR (reacción en cadena de la polimerasa) y cultivo. Tanto la microscopía como la PCR resultaron positivas, permitiendo identificar como especie involucrada Leishmania (Leishmania) amazonensis. Al aplicar el tratamiento específico para LM (antimoniato de meglumina I.M., 425mg cada 12 hs. durante 29 días) se logró la remisión completa de la sintomatología. CONCLUSIONES: La amplia variedad de manifestaciones clínicas en la Leishmaniasis obligan a realizar el diagnóstico diferencial con numerosas enfermedades.Fil: Monroig, Sibila. Hospital San Bernardo;Fil: Garcia Bustos, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: González Prieto, G. Universidad Nacional de Salta. Facultad de Ciencias de la Salud; ArgentinaFil: Ramos, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Segura, Graciela. Hospital San Bernardo;Fil: Barrio. Alejandra Beatriz. Universidad Nacional de Salta. Facultad de Ciencias de la Salud; Argentin

Solidaridad en la gubernamentalidad liberal avanzada: un análisis en piezas publicitarias

El artículo presenta una reflexión sobre la manera en que en los últimos veinte años la promoción de un determinado tipo de solidaridad en Chile ha contribuido a la conformación de una gubernamentalidad liberal avanzada, necesaria para la instalación de un programa neoliberal. La reflexión se enmarca en los aportes teóricos de Michel Foucault y tiene por objeto empírico piezas de publicidad de promoción de la solidaridad emitidas en Chile entre los años 2009 y 2010, que han sido analizadas en el contexto del proyecto Fondecyt 1090534. Se presentan tres tipos de resultados: (a) se describen los sectores sociales que se construyen como agentes de la solidaridad, (b) se reflexiona sobre las prácticas solidarias más promovidas y (c) se indaga en la forma en que se interpela a los sujetos a ser solidarios.L’article présente une réflexion sur la manière selon laquelle au cours des vingt dernières années la promotion d’un type de solidarité déterminé au Chili a contribué à la conformation d’une gouvernementalité libérale avancée, nécessaire à l’établissement d’un programme néolibéral. La réflexion s’inscrit dans les contributions théoriques de Michel Foucault et son objet empirique correspond à des extraits de publicité de promotion de la solidarité émis au Chili entre les années 2009 et 2010, analysées au sein du projet Fondecyt 1090534. Trois types de résultats sont présentés : (a) une description des secteurs sociaux qui se construisent en tant qu’agents de la solidarité, (b) une réflexion sur les pratiques solidaires les plus promues et (c) une analyse de la manière à travers laquelle les sujets sont invités à être solidaires.The article presents an analysis on the way in which during the last twenty years the promotion of a certain kind of solidarity in Chile has contributed to the formation of an advanced liberal governmentality, necessary for the installation of a neoliberal agenda. The reflection follows the theoretical contributions of Michel Foucault and focuses on the empirical analysis of ads that promote solidarity, issued in Chile between 2009 and 2010, in the context of the project FONDECYT 1090534.  We present three types of results: (a) description of the social sectors that are constructed as agents of solidarity, (b) analysis on the most promoted solidarity practices and (c) investigation on the way it adresses the people in order to raise their solidarity.O artigo apresenta uma reflexão sobre como a maneira de incentivar um certo tipo de solidariedade no Chile tem contribuído para a formação de uma governamentalidade liberal avançada, necessária para a instalação de uma agenda neoliberal. A reflexão recai sobre as contribuições teóricas de Michel Foucault e analisa anúncios para promover a solidariedade emitida no Chile entre 2009 e 2010, no contexto do projeto Fondecyt 1090534. Nós apresentamos três tipos de resultados: (a) descreve os setores sociais que são construídas como agentes de solidariedade, (b) reflete sobre as práticas de solidariedade mais promovidos e (c) investiga a forma como ele desafia o sujeito a ser solidário

Efectos de histéresis en la producción de un destilador

Con el objetivo de optimizar la producción de destilado se realizaron ensayos con un destilador de laboratorio sometido a calentamiento que reproduce el calentamiento solar de día claro, cuyas cubiertas tienen una pendiente de 20º y se compararon con resultados previos obtenidos con una pendiente de 45º. Se observó que tanto el destilado promedio horario como el destilado total diario eran mayores en el caso de mayor pendiente. Se comprobó que la producción depende de la historia del funcionamiento del destilador, mostrando un efecto de histéresis y se analizó la influencia estacional.With the aim of optimizing the distillate production essays were performed on a laboratory still with 20º inclination of the covers, under conditions similar to clear day solar heating. The results were compared with those obtained previously with a 45º slope in the covers. It was observed that the hourly mean distillate as well as the total daily distillate were higher in the case of higher slope and that the still production depends on the history of the functioning of the still, showing an hysteresis effect. The stational influence was analyzed.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

HIGIENE EN INSTALACIONES Y MANIPULACIÓN DE ALIMENTOS EN OCHO ORFANATOS DEL MUNICIPIO DE TORREÓN, COAHUILA (MEXICO)

Se realizó un estudio descriptivo transversal en 8 orfanatos de Torreón, México, para evaluar la higiene de la manipulación de alimentos y de de las instalaciones. Se visitaron los albergues y se formularon una serie de preguntas al personal directivo del centro, al personal de mantenimiento, y al personal de cocina.Posteriormente se realizó la inspección de las instalaciones. Los resultados del estudio mostraron que las condiciones higiénicas en la preparación de los alimentos, son deficientes en la mayoría de los orfanatos. Las condiciones de higiene y sanidad de las instalaciones variaron considerablemente entre las casas hogar, dependiendo del grado de compromiso de los trabajadores, de la antigüedad de los edificios y de los presupuestos económicos de las instituciones. Es necesario llevar a cabo acciones de capacitación en los trabajadores encaminadas a crear conciencia de la importancia de la higiene en la salud de los niños.Palabras clave: orfanatos, preparación higiénica de alimentos, sanidad e higiene de las instalacionesorphanages, sanitary and hygienic conditions, meal preparation, state of hygien

Venom alkaloids against Chagas disease parasite: search for effective therapies

Chagas disease is an important disease affecting millions of patients in the New World and is caused by a protozoan transmitted by haematophagous kissing bugs. It can be treated with drugs during the early acute phase; however, effective therapy against the chronic form of Chagas disease has yet to be discovered and developed. We herein tested the activity of solenopsin alkaloids extracted from two species of fire ants against the protozoan parasite Trypanosoma cruzi, the aetiologic agent of Chagas disease. Although IC50 determinations showed that solenopsins are more toxic to the parasite than benznidazole, the drug of choice for Chagas disease treatment, the ant alkaloids presented a lower selectivity index. As a result of exposure to the alkaloids, the parasites became swollen and rounded in shape, with hypertrophied contractile vacuoles and intense cytoplasmic vacuolization, possibly resulting in osmotic stress; no accumulation of multiple kinetoplasts and/or nuclei was detected. Overexpressing phosphatidylinositol 3-kinase—an enzyme essential for osmoregulation that is a known target of solenopsins in mammalian cells—did not prevent swelling and vacuolization, nor did it counteract the toxic effects of alkaloids on the parasites. Additional experimental results suggested that solenopsins induced a type of autophagic and programmed cell death in T. cruzi. Solenopsins also reduced the intracellular proliferation of T. cruzi amastigotes in infected macrophages in a concentration-dependent manner and demonstrated activity against Trypanosoma brucei rhodesiense bloodstream forms, which is another important aetiological kinetoplastid parasite. The results suggest the potential of solenopsins as novel natural drugs against neglected parasitic diseases caused by kinetoplastids.Fil: Silva, Rafael C. M. Costa. Universidade Federal do Rio de Janeiro; BrasilFil: Fox, Eduardo G. P.. Universidade Federal do Rio de Janeiro; Brasil. South China Agricultural University; ChinaFil: Gomes, Fabio M.. Universidade Federal do Rio de Janeiro; Brasil. National Institutes of Health; Estados UnidosFil: Feijó, Daniel F.. Universidade Federal do Rio de Janeiro; BrasilFil: Ramos, Isabela. Universidade Federal do Rio de Janeiro; BrasilFil: Koeller, Carolina M.. Universidade Federal do Rio de Janeiro; Brasil. University at Buffalo; Estados UnidosFil: Costa, Tatiana F. R.. Universidade Federal do Rio de Janeiro; BrasilFil: Rodrigues, Nathalia S.. Universidade Federal do Rio de Janeiro; BrasilFil: Lima, Ana P.. Universidade Federal do Rio de Janeiro; BrasilFil: Atella, Georgia C.. Universidade Federal do Rio de Janeiro; BrasilFil: Rocha de Miranda, Kildare. Universidade Federal do Rio de Janeiro; Brasil. Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem; BrasilFil: Schoijet, Alejandra Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Alonso, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: de Alcântara Machado, Ednildo. Universidade Federal do Rio de Janeiro; BrasilFil: Heise, Norton. Universidade Federal do Rio de Janeiro; Brasi

Mitochondrial Na+ controls oxidative phosphorylation and hypoxic redox signalling

All metazoans depend on O2 delivery and consumption by the mitochondrial oxidative phosphorylation (OXPHOS) system to produce energy. A decrease in O2 availability (hypoxia) leads to profound metabolic rewiring. In addition, OXPHOS uses O2 to produce reactive oxygen species (ROS) that can drive cell adaptations through redox signalling, but also trigger cell damage1–4, and both phenomena occur in hypoxia4–8. However, the precise mechanism by which acute hypoxia triggers mitochondrial ROS production is still unknown. Ca2+ is one of the best known examples of an ion acting as a second messenger9, yet the role ascribed to Na+ is to serve as a mere mediator of membrane potential and collaborating in ion transport10. Here we show that Na+ acts as a second messenger regulating OXPHOS function and ROS production by modulating fluidity of the inner mitochondrial membrane (IMM). We found that a conformational shift in mitochondrial complex I during acute hypoxia11 drives the acidification of the matrix and solubilization of calcium phosphate precipitates. The concomitant increase in matrix free-Ca2+ activates the mitochondrial Na+/Ca2+ exchanger (NCLX), which imports Na+ into the matrix. Na+ interacts with phospholipids reducing IMM fluidity and mobility of free ubiquinone between complex II and complex III, but not inside supercomplexes. As a consequence, superoxide is produced at complex III, generating a redox signal. Inhibition of mitochondrial Na+ import through NCLX is sufficient to block this pathway, preventing adaptation to hypoxia. These results reveal that Na+ import into the mitochondrial matrix controls OXPHOS function and redox signalling through an unexpected interaction with phospholipids, with profound consequences in cellular metabolism

Mortality risk factors in primary Sjögren syndrome:a real-world, retrospective, cohort study

BACKGROUND: What baseline predictors would be involved in mortality in people with primary Sjögren syndrome (SjS) remains uncertain. This study aimed to investigate the baseline characteristics collected at the time of diagnosis of SjS associated with mortality and to identify mortality risk factors for all-cause death and deaths related to systemic SjS activity measured by the ESSDAI score.METHODS: In this international, real-world, retrospective, cohort study, we retrospectively collected data from 27 countries on mortality and causes of death from the Big Data Sjögren Registry. Inclusion criteria consisted of fulfilling 2002/2016 SjS classification criteria, and exclusion criteria included chronic HCV/HIV infections and associated systemic autoimmune diseases. A statistical approach based on a directed acyclic graph was used, with all-cause and Sjögren-related mortality as primary endpoints. The key determinants that defined the disease phenotype at diagnosis (glandular, systemic, and immunological) were analysed as independent variables.FINDINGS: Between January 1st, 2014 and December 31, 2023, data from 11,372 patients with primary SjS (93.5% women, 78.4% classified as White, mean age at diagnosis of 51.1 years) included in the Registry were analysed. 876 (7.7%) deaths were recorded after a mean follow-up of 8.6 years (SD 7.12). Univariate analysis of prognostic factors for all-cause death identified eight Sjögren-related variables (ocular and oral tests, salivary biopsy, ESSDAI, ANA, anti-Ro, anti-La, and cryoglobulins). The multivariate CPH model adjusted for these variables and the epidemiological features showed that DAS-ESSDAI (high vs no high: HR = 1.68; 95% CI, 1.27-2.22) and cryoglobulins (positive vs negative: HR = 1.72; 95% CI, 1.22-2.42) were independent predictors of all-cause death. Of the 640 deaths with available information detailing the specific cause of death, 14% were due to systemic SjS. Univariate analysis of prognostic factors for Sjögren-cause death identified five Sjögren-related variables (oral tests, clinESSDAI, DAS-ESSDAI, ANA, and cryoglobulins). The multivariate competing risks CPH model adjusted for these variables and the epidemiological features showed that oral tests (abnormal vs normal results: HR = 1.38; 95% CI, 1.01-1.87), DAS-ESSDAI (high vs no high: HR = 1.55; 95% CI, 1.22-1.96) and cryoglobulins (positive vs negative: HR = 1.52; 95% CI, 1.16-2) were independent predictors of SjS-related death.INTERPRETATION: The key mortality risk factors at the time of SjS diagnosis were positive cryoglobulins and a high systemic activity scored using the ESSDAI, conferring a 2-times increased risk of all-cause and SjS-related death. ESSDAI measurement and cryoglobulin testing should be considered mandatory when an individual is diagnosed with SjS.FUNDING: Novartis.</p