Variabilidad del ADN cloroplástico y su contribución al conocimiento del estado de conservación de Ulmus glabra en el Sistema Central

En el presente trabajo se ha analizado la diversidad existente en el ADN cloroplástico (ADNcp) de 16 poblaciones distribuidas a lo largo del Sistema Central. Para ello, se ha empleado la técnica de PCR-RFLP (amplificación de fragmentos específicos y posterior digestión con enzimas de restricción) sobre 38 regiones del ADNcp (Grivet et al., 2001)

Identificación de homonimias en accesiones de Phaseolus vulgaris L. de la colección de frijol de Honduras

El frijol (Phaseolus vulgaris L.) es una leguminosa muy importante en la dieta diaria en Honduras, representa el segundo grano básico en importancia nacional. En la Escuela Agrícola Panamericana se encuentra localizado el Banco de Germoplasma de frijol de Honduras, donde se conservan 497 accesiones. Para este estudio se han seleccionado 56 de esas accesiones, 30 de ellas denominadas “Vaina Blanca”, 20 con el nombre de “Arbolito”, cuatro “Arbolito Vaina Blanca” y dos “Vaina Blanca Arbolito”, lo cual representa el 11% de la colección. Para la identificación y detección de homonimias en dicho material vegetal mediante marcadores moleculares, se han utilizado 12 microsatélites previamente descritos en P. vulgaris. Los resultados obtenidos muestran la existencia de una gran variabilidad en las 56 accesiones estudiadas. Se han detectado 48 genotipos diferentes, de manera que resulta imposible asignar un genotipo concreto tanto para el cultivar “Vaina Blanca” como para “Arbolito”

Variabilidad genética en razas locales de frijol común de Honduras

Las regiones agroecológicas Centro-Oriental (Francisco Morazón y El Paraíso) y Nor-Oriental (Olancho) aportan el 52% de la producción de frijol común (Phaseolus vulgaris) en Honduras. En el presente estudio se ha analizado la variabilidad genética en 59 razas locales colectadas en los tres departamentos de las dos regiones agroecológicas mencionadas, mediante cuatro loci microsatélites previamente descritos en P. vulgaris. Los resultados obtenidos muestran la existencia de una gran variabilidad en las 59 accesiones estudiadas, habiéndose detectado 53 genotipos diferentes. Por otra parte, los bajos valores de heterocigosis observados reflejan la condición eminentemente autógama de P. vulgaris

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements