Lagrangians for Massive Dirac Chiral Superfields

A variant for the superspin one-half massive superparticle in $4D$, $\mathcal{N}=1$, based on Dirac superfields, is offered. As opposed to the current known models that use spinor chiral superfields, the propagating fields of the supermultiplet are those of the lowest mass dimensions possible: scalar, Dirac and vector fields. Besides the supersymmetric chiral condition, the Dirac superfields are not further constrained, allowing a very straightforward implementation of the path-integral method. The corresponding superpropagators are presented. In addition, an interaction super Yukawa potential, formed by Dirac and scalar chiral superfields, is given in terms of their component fields. The model is first presented for the case of two superspin one-half superparticles related by the charged conjugation operator, but in order to treat the case of neutral superparticles, the Majorana condition on the Dirac superfields is also studied. We compare our proposal with the known models of spinor superfields for the one-half superparticle and show that it is equivalent to them.Comment: 22 pages. Matches published versio

Electroweak phase transition in a model with gauged lepton number

In this work we study the electroweak phase transition in a model with gauged lepton number. Here, a family of vector-like leptons is required in order to cancel the gauge anomalies. Furthermore, these leptons can play an important role in the transition process. We find that this framework is able to provide a strong transition, but only for a very limited number of cases.Comment: 14 pages, 5 figures, matches published versio

Tropical Grass Growth Functions Modeling by Using Nonlinear Mixed Models

Nonlinear Growth curves are used for modeling plant physiological variables. These models are preferable because the polynomial coefficients of the equations have a biological significance. The response variables of the curves occurs commonly with repeated measurements over time and measurements are on different environments. The traditional statistical analysis does not include a repeated measures approach, which can lead to improper estimation of the error terms. It is important to study the growth of tropical grass (Da Silva and Carvalho 2005)

Análisis de crecimiento del pasto Toledo Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster en clima cálido subhúmedo

Objective: Perform a growth analysis of Toledo grass (Urochloa brizantha CIAT 26110) during de rainy season, from sowing to 180 days, to determine the optimum harvesting moment. Design/methodology/approach: The morphological composition (CM), growth rate (GR), plant height, intercepted radiation (RI), leaf / stem ratio (L:S), leaf / non-leaf (L:NL), and biomass accumulation were evaluated every fifteen days during a 180 days period, except for the first two samples (monthly). Data were analyzed using the GLM procedure of SAS, under an experimental design of randomized blocks, with repeated measures over time, with three replicates.  Results: The CM varied significantly (P<0.01) through the different physiological states. The maximum production of aerial biomass (19.9 t DM ha-1) and GR (131.9 kg DM ha-1 day-1) were reached 150 days after sowing (dap) and that of leaves (3.9 t DM ha-1) was at 135 dap. At this time the RI was 100% and the height of plant was 106 cm. Limitations on study/implications: Toledo grass should be planted in the rainy season to be used when the canopy reaches a coverage greater than 80%, because the proportion of leaves decreases as the age of the plant progresses. Findings/conclusions: The highest accumulated total biomass, so it is suggested that the cut be made at 135 days after plantingObjetivo: realizar un análisis de crecimiento del pasto Toledo (Urochloa brizantha CIAT 26110) en la época de lluvias, desde la siembra hasta los 180 días, para determinar el momento óptimo de cosecha. Diseño/metodología/aproximación: Se evaluó la composición morfológica (CM), tasa de crecimiento (TC), altura de planta, radiación interceptada (RI), relación hoja/tallo (H:T), hoja/no hoja (H:NH) y la acumulación de biomasa aérea, a intervalos de quince días, a excepción de los dos primeros muestreos que fueron mensuales. Los datos fueron analizados mediante el procedimiento GLM de SAS, bajo un diseño experimental de bloques al azar, con medidas repetidas en el tiempo, con tres repeticiones. Resultados: La CM varió (P£0.01) a través de los diferentes estados fisiológicos. La máxima producción de biomasa aérea (19.9 t MS ha-1) y TC (131.9 kg MS ha-1 día-1) se alcanzó a los 150 días después de la siembra (dds), y la de hojas (3.9 t MS ha-1) fue a los 135 dds, en este momento la RI fue del 100% y la altura de 106 cm. Limitaciones del estudio/implicaciones: El pasto Toledo debe ser sembrado a inicio de la época de lluvias para ser usado cuando la cobertura del suelo sea mayor a 80 %, debido a que la proporción de hojas decrece conforme avanza la edad de la planta. Hallazgos/conclusiones: La máxima TC coincidió con la mayor biomasa total acumulada a los 135 (dds), por lo que se sugiere realizar el corte en este momento

Influence of the game context and levels of physical activity on the behavior of basketball coaches

Coaches can exert a significant influence on players and games. The aim of this study is to assess behavior in the form of heart rate (HR) responses and distance traveled of basketball head coaches during matches considering the different match contexts faced as a score differences and time outs during the game direction and levels of physical activity and coaches experience. Four basketball head coaches are recruited in this case report. Mean and maximal absolute and relative HR are determined across matches. Scoring streaks (±6 consecutive points) and time outs are considered as influence value. The in-match distance traveled measured using microsensors, coaching experience, and daily activity on HR responses is also determined. Higher HR are evident across matches compared to periods prior to and following matches. HR is significantly (P <.05) elevated during later time-outs compared to earlier time-outs, with positive scoring streaks yielding a tendency towards higher HR compared to negative and no scoring streaks. Experience (rs= -0.91, P <.001), daily activity levels (rs = -0.83, P <.001), and weekly METS (rs= -0.78, P =.002) are negatively associated with match HR, while in-match distance (rs= 0.69, P =.013) is positively associated with match HR. These data indicate that matches elevate the cardiovascular stress imposed on basketball head coaches, with later time-outs and positive scoring streaks promoting heightened HR. Moreover, in-match activity and personal characteristics (less experience and lower physical activity) further augment match HR in coaches