Efecto de la labor de despunte, realizada con distintas longitudes de estilo en las mazorcas, sobre el rendimiento de maiz semillero (Zea mays)

37 p.Se evaluó el efecto de la labor de despunte realizada con distintas longitudes de estilos en las mazorcas, sobre el rendimiento de maíz semillero (Zea mays). El experimento se insertó dentro de un cultivo de producción comercial de semillas híbridas; se ocupó como semilla básica dos líneas puras de maíz proporcionadas por la empresa ANASAC. Se utilizaron cuatro longitudes de estilo más un tratamiento testigo sin despuntar: T1 sin estilos expuesto, T2 inicio de emergencia de los estilos, T3 estilos con 2,5 cm. de longitud, T4 estilos con 5 cm. de longitud, y T0 testigo sin despuntar. Se utilizó un diseño completamente al azar, utilizando cuatro repeticiones por tratamiento; cada unidad experimental estuvo compuesta por cinco plantas. Los tratamientos a los estilos se realizaron en la etapa de floración del semillero. Para determinar el momento para realizar el despunte en cada tratamiento, se midió con una regla la longitud de los estilos desde que estos estaban expuestos, tomando la medida desde el ápice del estilo hasta el punto de emergencia del estilo con respecto a las hojas envolventes. La cosecha se efectuó el 15 de marzo del 2006, con una humedad de 38 %. Después de la cosecha, se procedió a secar las mazorcas durante 80 horas con aire forzado a 35º C hasta alcanzar 12,5 % de humedad en los granos. Luego se desgranó manualmente cada mazorca y se realizaron las siguientes mediciones: número total de hileras por mazorca, número total de granos por mazorca, peso de los granos por mazorca. Los resultados obtenidos permiten concluir que no hubo diferencias estadísticas entre los tratamientos sobre el número de hileras por mazorca. Realizar el despunte con longitudes de 2,5 cm. de estilos redujo en forma significativa tanto el número de granos por mazorca como el peso total de los granos por mazorca, respecto a los demás tratamientos

Síndromes compresivos del nervio mediano. Revisión y actualización de la bibliografía

El nervio mediano desciende por el brazo y, en el codo, comienza a atravesar estructuras que pueden generar compresión, como el ligamento de Struthers, el lacertus fibrosus, el pronador redondo, el flexor superficial de los dedos. Finalmente, en la muñeca, se encuentra otro sitio de compresión producido por el ligamento transverso del carpo. Todas estas estructuras pueden provocar signos y síntomas de atrapamiento nervioso y favorecer el deterioro funcional del nervio. Nuestro objetivo es dar a conocer una actualización sobre estos sitios de atrapamiento del nervio mediano, y cómo realizar un diagnóstico preciso e indicar un tratamiento adecuado

The Bacterial Product Violacein Exerts an Immunostimulatory Effect Via TLR8

Violacein, an indole-derived, purple-colored natural pigment isolated from Chromobacterium violaceum has shown multiple biological activities. In this work, we studied the effect of violacein in different immune cell lines, namely THP-1, MonoMac 6, ANA-1, Raw 264.7 cells, as well as in human peripheral blood mononuclear cells (PBMCs). A stimulation of TNF-α production was observed in murine macrophages (ANA-1 and Raw 264.7), and in PBMCs, IL-6 and IL-1β secretion was detected. We obtained evidence of the molecular mechanism of activation by determining the mRNA expression pattern upon treatment with violacein in Raw 264.7 cells. Incubation with violacein caused activation of pathways related with an immune and inflammatory response. Our data utilizing TLR-transfected HEK-293 cells indicate that violacein activates the human TLR8 (hTLR8) receptor signaling pathway and not human TLR7 (hTLR7). Furthermore, we found that the immunostimulatory effect of violacein in PBMCs could be suppressed by the specific hTLR8 antagonist, CU-CPT9a. Finally, we studied the interaction of hTLR8 with violacein in silico and obtained evidence that violacein could bind to hTLR8 in a similar fashion to imidazoquinoline compounds. Therefore, our results indicate that violacein may have some potential in contributing to future immune therapy strategies.Universidad de Costa Rica/[801-B2-519]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[FI-497-11]/MICITT/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[DFG-TR84]/MICITT/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[DFG-KFO325]/MICITT/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones Farmacéuticas (INIFAR

Memoria del IV Coloquio Internacional sobre Diversidad Cultural y Estudios Regionales

Esta memoria del IV Coloquio Internacional sobre Diversidad Cultural y Estudios Regionales: Escenarios de la heterogeneidad, memorias y culturas, realizada por el Centro de Investigaciones sobre Diversidad Cultural y Estudios Regionales, CIDICER, en 2016, compila las ponencias presentadas, las cuales se organizan por ejes temáticos, en 7 apartados: Culturas, Identidades e Imaginarios, Literatura Cultura e Identidades, Estéticas de la Heterogeneidad, Pluriculturalidad y Grupos Minoritarios, Diversidad Cultural e Identidades, Literatura, Identidades y Género.UCR::Sedes Regionales::Sede de Occidente::Recinto San Ramón::Centro de Investigaciones sobre Diversidad Cultural y Estudios Regionales (CIDICER

Obeticholic acid for the treatment of non-alcoholic steatohepatitis: interim analysis from a multicentre, randomised, placebo-controlled phase 3 trial

Background Non-alcoholic steatohepatitis (NASH) is a common type of chronic liver disease that can lead to cirrhosis. Obeticholic acid, a farnesoid X receptor agonist, has been shown to improve the histological features of NASH. Here we report results from a planned interim analysis of an ongoing, phase 3 study of obeticholic acid for NASH. Methods In this multicentre, randomised, double-blind, placebo-controlled study, adult patients with definite NASH,non-alcoholic fatty liver disease (NAFLD) activity score of at least 4, and fibrosis stages F2–F3, or F1 with at least oneaccompanying comorbidity, were randomly assigned using an interactive web response system in a 1:1:1 ratio to receive oral placebo, obeticholic acid 10 mg, or obeticholic acid 25 mg daily. Patients were excluded if cirrhosis, other chronic liver disease, elevated alcohol consumption, or confounding conditions were present. The primary endpointsfor the month-18 interim analysis were fibrosis improvement (≥1 stage) with no worsening of NASH, or NASH resolution with no worsening of fibrosis, with the study considered successful if either primary endpoint was met. Primary analyses were done by intention to treat, in patients with fibrosis stage F2–F3 who received at least one dose of treatment and reached, or would have reached, the month 18 visit by the prespecified interim analysis cutoff date. The study also evaluated other histological and biochemical markers of NASH and fibrosis, and safety. This study is ongoing, and registered with ClinicalTrials.gov, NCT02548351, and EudraCT, 20150-025601-6. Findings Between Dec 9, 2015, and Oct 26, 2018, 1968 patients with stage F1–F3 fibrosis were enrolled and received at least one dose of study treatment; 931 patients with stage F2–F3 fibrosis were included in the primary analysis (311 in the placebo group, 312 in the obeticholic acid 10 mg group, and 308 in the obeticholic acid 25 mg group). The fibrosis improvement endpoint was achieved by 37 (12%) patients in the placebo group, 55 (18%) in the obeticholic acid 10 mg group (p=0·045), and 71 (23%) in the obeticholic acid 25 mg group (p=0·0002). The NASH resolution endpoint was not met (25 [8%] patients in the placebo group, 35 [11%] in the obeticholic acid 10 mg group [p=0·18], and 36 [12%] in the obeticholic acid 25 mg group [p=0·13]). In the safety population (1968 patients with fibrosis stages F1–F3), the most common adverse event was pruritus (123 [19%] in the placebo group, 183 [28%] in the obeticholic acid 10 mg group, and 336 [51%] in the obeticholic acid 25 mg group); incidence was generally mild to moderate in severity. The overall safety profile was similar to that in previous studies, and incidence of serious adverse events was similar across treatment groups (75 [11%] patients in the placebo group, 72 [11%] in the obeticholic acid 10 mg group, and 93 [14%] in the obeticholic acid 25 mg group). Interpretation Obeticholic acid 25 mg significantly improved fibrosis and key components of NASH disease activity among patients with NASH. The results from this planned interim analysis show clinically significant histological improvement that is reasonably likely to predict clinical benefit. This study is ongoing to assess clinical outcomes

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Relación entre nematodos y la productividad del banano (Musa AAA) en Ecuador

El objetivo del presente trabajo fue determinar el efecto de los nematodos en la producción de banano. En seieis hectáreaeas, en el 2007, dentro de una plantación comerciaial de banano en Ecuador, 110 hijos de sucesión de 1,5-1,75 m de altura de plantas recién florecidas fueron muestreaeados papara estimar el contenido de raíces y número de nematodos. Las raíces fueron lavadas, pepesadas, licuadas y los nematodos recolectados en una criba de 0,025 mm (población = número por 100 g de raíces). A la cosecha de las plantas madre se registró el pepeso del racimo, número de manos y la calibración promedio de los tres frutos centrales de la fila externa de la segunda mano basal. Con excepción del agrupapamieiento de plantas por número de R. similis, el pepeso de raíz funcional sieiempre correlacionó (r > 0,94; p < 0,0068) con el pepeso de raíz total. Indepeepeependieientemente, del agrupapamieiento de plantas, R. similis sieiempre correlacionó (r > 0,84; p < 0,0217) con nematodos totales. Cuando las plantas fueron agrupapas por pepeso de raíz total, R. similis (r= 0,86; P= 0,0287) y nematodos totales (r= 0.89; P= 0.0156) correlacionaron con el número de manos por racimo. Al agrupapar los hijos por el número de R. similis, se encontró que conforme aumentó el nematodo se redujo el pepeso de raíz funcional (r= -0,96; P= 0,0080) y total (r= -0,98; P= 0,0028). En experimentos futuros debería relacionarse la población de nematodos de plantas cerca de, o a la diferenciación floral, con su rendimiento