84 research outputs found
Parent selection to maximize heterosis expression in soybean (Glycine max L. [Merr.])
Utilization of heterosis effects in breeding soybean (Glycine max (L.) Merr) cultivars for commercial production is still a possibility. One objective of this research was to determine heterosis expression in soybean germplasms obtained from the crossing of parents selected on the basis of restriction fragment length polymorphism (RFLP) diversity and isozyme loci (ISO) constitution compared to parents selected for high-yielding (HY) ability and differences in geographic origin (GO). The second objective was to compare mean heterotic performance of F[subscript]1 hybrids and F[subscript]2 bulks evaluated in hill- and row-plots;Twenty-one genotypes of each of Maturity Groups (MG) II and III, selected according to four criteria: HY, and for differences in RFLP, ISO, and GO were used in crossing to obtain 24 F[subscript]1 hybrids and their F[subscript]2 bulks. Parents, F[subscript]1 hybrids, and F[subscript]2 bulks grown in hill plots and parents and F[subscript]2 bulks grown in row plots were evaluated for seed yield (YLD), days to physiological maturity (MAT), lodging (LDG), height (HT), days to flowering (FLW), seed weight (SDWT), and protein (PROT) and oil (OIL) content in 1990 and 1991. Midparent (MPH) and high-parent (HPH) heterosis for the F[subscript]1 and F[subscript]2 generations were calculated for each hybrid combination. RFLP-based genetic distances among the parents of each hybrid were obtained and correlated with heterotic effects for YLD. Phenotypic and rank correlation coefficients for YLD were calculated over all criteria between all possible combinations of generations and plot types;The results indicated that of the two criteria at the molecular level, selecting parents for different isozyme constitution was more advantageous for the expression of heterosis in seed yield than the use of RFLP differences. The results observed in the study suggest that in soybean, the measure of genetic distances calculated from RFLP data may not be effective in establishing the genetic information required for the prediction of hybrid performance;The evaluations conducted in the F[subscript]1 and F[subscript]2 generations in hill and row plots of both MGs, suggested that midparent heterotic effects determined at the F[subscript]2 generation in hills could be of value to predict the F[subscript]1 hybrid heterotic performance if they also were planted in hill plots. There was no association between the heterotic expression evaluated in the F[subscript]2 generation tested in rows and in the F[subscript]1 generation planted in hills. (Abstract shortened by UMI.
Un indicador visual de la madurez fisiológica de habichuelas de inflorescencia indeterminada
Two indeterminate breeding lines, L-227 and RAB 205, were planted during two growing seasons for the purpose of identifying a visual indicator of physiological maturity of dry beans which could be used in the field. Ten-plant samples were taken at 2-day intervals beginning approximately 8 weeks after emergence to determine seed dry weight accumulation and number of green, yellow, and brown pods. In order to identify a stage of pod development which coincided with maximum accumulation of seed dry weight, the number of green, yellow and brown pods per plant was estimated with polinomial regression equations. Coefficients of determination for the number of yellow pods were relatively low, ranging from 0.52 to 0.77, whereas the coefficients of determination for most equations for green and brown pod numbers were near 0.9, indicating that the number of both green and brown pods may be useful as indicators of the occurrence of physiological maturity. Physiological maturity of L-227 occurred when plants had developed 1 to 2 green pods and 12 to T4 brown pods, whereas physiological maturity of RAB 205 occurred when 2 green pods and 8 brown pods were present on each plant. In the field, the number of green pods would be a better visual indicator of physiological maturity than the number of brown pods because fewer green pods have to be counted and because the green pods are on top of the plant.Dos líneas indeterminadas de habichuela, L-227 y RAB 205, se sembraron en dos estaciones del año para identificar un indicador visual de la etapa de madurez fisiológica que pudiera usarse en el campo. Muestras de 10 plantas se tomaron cada 2 días para determinar la acumulación de materia seca en el grano y el número de vainas verdes, amarillas y secas. Se usaron ecuaciones de regresión lineales, cuadráticas y cúbicas para determinar el número de vainas verdes, amarillas y secas que coincidian con el punto de máxima acumulación de peso seco en el grano. Los coeficientes de determinación para el número de vainas amarillas fueron relativamente bajos; variaron de 0.52 a 0.77. Por otro lado, la mayoría de los coeficientes de determinación para las ecuaciones del número de vainas verdes y de secas fueron cercanos a 0.9, lo que indica que tanto el número de vainas verdes como el de vainas secas podían ser buenos indicadores de madurez fisiológica. La madurez fisiológica de L-227 ocurrió cuando a las plantas les quedaban de 1 a 2 vainas verdes y tenían de 12 a 14 vainas secas. La madurez fisiológica de RAB 205 ocurrió cuando las plantas tenían 2 vainas verdes y 8 vainas secas. Estos resultados indican que el número de vainas verdes, en condiciones de campo, podría ser un mejor indicador de la madurez fisiológica que el número de vainas secas, no solamente porque habrá menos vainas verdes que contar, sino porque las verdes estarían en la parte superior de la planta
Estabilidad del rendimiento de algunos genotipos de habichuela en Honduras
Bean (Phaseolus vulgaris L.) cultivars are grown under diverse environmental conditions in Central America because of geography, multiple growing seasons and variable inputs. The regression of mean genotype yields onto mean environment yields may provide useful information for selecting beans with greater yield stability when grown under these conditions. The principal objective of this research was to test yield stability of bean cultivars and promising breeding lines across a range of environments representative of the bean growing regions of Honduras. In 1984, 25 cultivars/breeding lines of various origins were grown in 23 field trials in Honduras. The trials were conducted during two seasons and in three different departments. Stability was examined on the basis of mean square deviations (MSD) from regression, large rank order changes among mean seed yield of genotypes were evident when different seasons and departments were compared. A highly significant correlation of the regression slope (b) with mean genotype yield supported use of MSD to assess yield stability. Mean yield and MSD were not correlated. The two determinate cultivars in the trial had poor stability characteristics. Honduran varieties had greater yield and better stability characteristics than most entries in the trial. Black-seeded lines 'B-190', '3B-5-1' and '8325-7' had high mean yield and good stability characteristics. These results show the importance of testing for yield stability if a cultivar is to be released for use in different regions and seasons in Central American countries. Also high yield and stability, judged on the basis of MSD, can occur in the same genotype.Varias cultivares de habichuela (Phaseolus vulgaris L.) se sembraron en América Central en una variedad de condiciones ambientales debido a la geografía de las áreas de siembra y a las diversas estaciones de crecimiento a lo largo de todo el año. Las regresiones de los promedios de rendimiento de los genotipos y de los rendimientos medios por ambiente pueden proveer información valiosa para seleccionar líneas con una mejor estabilidad de rendimiento. El objetivo principal de esta investigación fue estudiar la estabilidad de rendimiento de cultivares y líneas de mejoramiento de habichuela con características prometedoras para autorizar su uso en tres áreas productoras de habichuela de Honduras. Los experimentos se sembraron durante dos épocas de siembra en tres departamentos del país. La estabilidad de rendimiento se determinó a partir de las desviaciones del cuadrado medio (MSD). De las regresiones se pudo observar grandes cambios en el orden de los genotipos cuando se compararon las épocas y los lugares de siembra. Una correlación altamente significativa entre la pendiente de regresión y el promedio de rendimiento por genotipo respalda el uso del método de las MSD para estudiar estabilidad de rendimiento. El promedio de rendimiento y las MSD no estuvieron correlacionados. Las dos cultivares determinadas incluidas en los exprerimentos presentaron características pobres de estabilidad. De las cuatro variedades de Honduras, dos de ellas tuvieron mejores rendimientos y estabilidad que la mayoría de las cultivares incluidas en los experimentos. Las líneas negras B-190, 3B-5-1 y 8325-7 presentaron buena estabilidad y excelentes promedios de rendimiento. Estos resultados muestran la importancia que tiene estudiar la estabilidad de rendimiento de una cultivar de frijol que se autoriza para sembrarse en diferentes regiones y estaciones de siembra de los países centroamericanos y también nos indica que y los altos rendimientos y la estabilidad medidos a base de las MSD pueden estar presentes en el mismo genotipo
Evaluación de riesgos laborales por puestos de trabajo en el taller de la empresa Industria López, Managua
Identificación de riesgos de los cuales destacan los riesgos físicos como “afectaciones auditivas” y otros colectivos como “incendio por cortocircuito” e “incendio por combustión de gas licuado de petróleo”, ambos relacionados a condiciones deplorables seguridad, problemas con espacio y limpieza y la inexistencia total de equipos de lucha contra incendio como son los extintores, hasta entonces el taller de la empresa Industrias López se encontraba en niveles muy bajos correspondiente a la higiene y seguridad ocupacional, por lo que, para fundamentar la evidencia encontrada se procedió a evaluar los riesgos definidos por puestos de trabajo con la normativa “ Acuerdo Ministerial jchg-000-0809 Procedimiento técnico de higiene y seguridad del trabajo para la evaluación de riesgo en los centros de trabajo
Cuidado humanizado y satisfacción del paciente del servicio de medicina de un hospital público, Trujillo-2022
El presente estudio tiene como objetivo determinar la relación entre cuidado
humanizado y satisfacción del paciente del servicio de medicina del hospital público,
Trujillo -2022. Es de tipo básica, de diseño correlacional, de corte transversal, con
una muestra de 62 pacientes, por lo cual, se aplicó un cuestionario
multidimensional de percepción de comportamientos de cuidado humanizado de
enfermería (PCHE) y el cuestionario multidimensional sobre satisfacción de usuaria
SERVQUAL, adaptados para su aplicación en pacientes hospitalizados en el
servicio de medicina. Los resultados obtenidos fueron que el 40.3% consideran un
cuidado humanizado regular y a la vez se sienten poco satisfechos, mientras que en
su minoría el 1.6% consideran un cuidado humanizado regular y se sienten
insatisfechos, con relación al cuidado humanizado el 50 % de pacientes
encuestados consideran que existe un nivel bueno, por el contrario, la minoría del
8.1% nivel malo y en base a la satisfacción del paciente se obtuvo que el 71% se
muestran poco satisfechos, y por el contrario la minoría de del 9.7% insatisfechos.
Concluyendo que existe relación significativa entre el cuidado humanizado de
enfermería y satisfacción del paciente del servicio de medicina del hospital
público, Trujillo – 2022, dado que se encuentra dentro de los parámetros
aceptables de (0.625) del coeficiente de Spearman
Moderate-to-Vigorous Physical Activity is Related With Retinal Neuronal and Axonal Integrity in Persons With Multiple Sclerosis
Background
Moderate-to-vigorous physical activity (MVPA) may confer benefits for axonal and/or neuronal integrity in adults with multiple sclerosis (MS). Purpose
Examine the association between device-measured MVPA with optical coherence tomography (OCT) metrics of retinal nerve fiber layer (RNFL) thickness and total macular volume (TMV) in persons with and without MS. Methods
Adults with MS (N = 41), along with sex-matched healthy control (HC) participants (N = 79), underwent measurements of retinal morphology via OCT and wore an accelerometer for a period of 7 days as a measure of MVPA. Results
Persons with MS had significantly lower MVPA, RNFL thickness, and TMV compared with HCs. MVPA was correlated with RNFL (r = .38, P \u3c .01) thickness and TMV (r = .49, P \u3c .01). Hierarchical linear regression analyses indicated that addition of MVPA attenuated the Group effect on RNFL and TMV. MVPA accounted for 8% and 3% of the variance in TMV (β = .343, P \u3c .01) and RNFL thickness (β = .217, P = .03), respectively. Conclusion
MVPA was positively associated with axonal and neuronal integrity assessed by OCT and partially explained group differences in those metrics. These results present possible future targets for MS management by increasing MVPA
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
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