On the order of BEC transition in weakly interacting gases predicted by mean-field theory

Predictions from Hartree-Fock (HF), Popov (P), Yukalov-Yukalova (YY) and $t$-matrix approximations regarding the thermodynamics from the normal to the BEC phase in weakly interacting Bose gases are considered. By analyzing the dependence of the chemical potential $\mu$ on temperature $T$ and particle density $\rho$ we show that none of them predicts a second-order phase transition as required by symmetry-breaking general considerations. In this work we find that the isothermal compressibility $\kappa_{T}$ predicted by these theories does not diverge at criticality as expected in a true second-order phase transition. Moreover the isotherms $\mu=\mu(\rho,T)$ typically exhibit a non-singled valued behavior in the vicinity of the BEC transition, a feature forbidden by general thermodynamic principles. This behavior can be avoided if a first order phase transition is appealed. The facts described above show that although these mean field approximations give correct results near zero temperature they are endowed with thermodynamic anomalies in the vicinity of the BEC transition. We address the implications of these results in the interpretation of current experiments with ultracold trapped alkali gases.Comment: 16 pages, 5 figure

Determination of competencies in veterinary medicine within the socio-humanistic axis

El objetivo del presente trabajo fue determinar las competencias y asignaturas correspondientes del eje socio humanístico dentro del nuevo plan de estudios de la Licenciatura de Medicina Veterinaria y Zootecnia de la Universidad Autónoma de Zacatecas. El nuevo plan de estudios, que contemplan dichas competencias del eje socio humanístico, surge ante la necesidad de la revisión periódica de los contenidos del programa de licenciatura, además de que es un indicador de los organismos acreditadores.  Para cumplir con el objetivo, se organizaron mesas de trabajo con los núcleos académicos básicos de docentes expertos en educación veterinaria de la unidad académica. Se estableció la metodología propia para lograr los concesos respectos de las competencias del eje socio humanístico. Para ello, se tuvo el apoyo de la información científica, de marcos referenciales tanto locales, nacionales e internacionales de las competencias del médico veterinario zootecnia con el enfoque humanístico hacia una sola salud. Dentro de las competencias socio humanísticas resultantes de los concesos sobresalen: eficientar los procesos administrativos en los servicios médico veterinarios, ser capaz de elaborar, gestionar y ejecutar proyectos de producción agropecuaria, aplicar modelos de desarrollo rural sostenible preservando el bienestar animal como eje fundamental, tener la capacidad de identificar la actividad empresarial inherente a los servicios medico veterinarios y de la producción pecuaria y tener la capacidad de  comunicación. Se concluyó que el perfil profesional del médico veterinario debe contener un buen porcentaje de competencias socio humanísticas las cuales están dentro de materias específicas y contempladas de manera transversal en los distintos ejes del plan de estudios.The objective of this work was to determine the competences and corresponding subjects of the socio-humanistic axis within the new curriculum of the Degree in Veterinary Medicine and Zootechnics of the Autonomous University of Zacatecas. The new curriculum, which contemplates these competences of the socio-humanistic axis, arises from the need for periodic review of the contents of the bachelor's degree program, in addition to being an indicator of the accrediting bodies. To meet the objective, working groups were organized with the basic academic nuclei of expert teachers in veterinary education of the academic unit. The own methodology was established to achieve the concessions regarding the competences of the socio-humanistic axis. To this end, we had the support of scientific information, both local, national and international reference frameworks of the competences of the veterinary doctor zootechnics with the humanistic approach towards a single health. Among the socio-humanistic competences resulting from the concessions stand out: making the administrative processes in the veterinary medical services more efficient, being able to elaborate, manage and execute agricultural production projects, applying sustainable rural development models preserving animal welfare as a fundamental axis, having the ability to identify the business activity inherent in veterinary medical services and livestock production and having communication skills. It was concluded that the professional profile of the veterinarian must contain a good percentage of socio-humanistic competences which are within specific subjects and contemplated in a transversal way in the different axes of the curriculum. &nbsp

Precision Measurement of the π+→e+νe Branching Ratio in the PIENU Experiment

The PIENU experiment at TRIUMF aims to measure the branching ratio of the pion decay modes Rπ=[π+→e+νe(γ)]/[π+→μ+νμ(γ)] with precision of <0.1%. Precise measurement of Rπ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented

Ecological impact of revegetation on a microphilous desert scrub ecosystem

Este trabajo presenta los resultados obtenidos en dos monitoreos realizados sobre un área revegetada de un matorral desértico micrófilo, al sur de la provincia biótica del Desierto Chihuahuense, para evaluar la situación que guardan sus especies representativas: Parthenium incanum, Larrea tridentata, Salvia ballotiflora, Acacia constricta, Lycium berlandieri, Jatropha dioica y Atriplex canescens; en dos tipos de suelo: somero y profundo, a 10 y 20 años de haber sido tratada. El estudio se llevó a cabo sobre franjas aclareadas con presencia de curvas a nivel, bajo un diseño de bloques completos al azar con 5 repeticiones, utilizando transectos de muestreo de 50 m2. Se registró la abundancia relativa (Ar), la frecuencia relativa (Fr), y la dominancia relativa (Dr) de las especies estudiadas. Se estudiaron los efectos de los factores principales y de las interacciones entre a) especie y suelo; b) especie y tratamiento, y c) especie y año de muestreo. Se encontraron diferencias significativas entre en la Ar, para todas las interacciones, y para la Dr se encontró diferencia significativa solo para la interacción entre especies y tratamiento. Finalmente, con respecto al de grado de progreso de las especies en el intervalo entre los años 2010 y 2020todas ellas, a excepción de la Jatropha dioica y la Atriplex canescens, presentaron un incremento que mostraron una disminución ligera en sus poblaciones. Además, los resultados obtenidos indican que no existió un impacto negativo de la revegetación aplicada en el año 2000, sobre las especies representativas del ecosistema de estudio, a 20 años de su ejecuciónThis paper presents the results obtained in two monitoring studies carried out on a revegetated area of a microphilous desert scrubland, at the south of the biotic province of the Chihuahuan Desert, to assess the conditions of its representative species: Parthenium incanum, Larrea tridentata, Salvia ballotiflora, Acacia constricta, Lycium berlandieri, Jatropha dioica and Atriplex canescens; in two types of soil: shallow and deep, 10 and 20 years after having been revegetated. The study was carried out on cleared fringes with the presence of contour lines, under a randomized complete block design with 5 replications, using 50 m2 sampling transects. Relative abundance (Ar), relative frequency (Fr), and relative dominance (Dr) of the species studied were recorded. Effects of the main factors and interactions between a) species and soil; b) species and treatment, and c) species and sampling year were studied. Significant differences were found between Ar, for all interactions, and for Dr a significant difference was found only for the interaction between species and treatment. Finally, with respect to the degree of progress of the species in the interval between 2010 and 2020, all of them, except for Jatropha dioica and Atriplex canescens, presented an increase and showed a slight decrease in their populations. In addition, the results obtained indicate that there was no negative impact of the revegetation applied in 2000 on the species representative of the study ecosystem, 20 years after its implementation

Status of the TRIUMF PIENU Experiment

The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio $R={\Gamma}({\pi}^+{\rightarrow}e^+{\nu}_e({\gamma}))/{\Gamma}({\pi}^+{\rightarrow}{\mu}^+{\nu}_{\mu}({\gamma}))$ with precision $<0.1$% to provide a sensitive test of electron-muon universality in weak interactions. The current status of the PIENU experiment is presented.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 4 eps figure

Improved Search for Heavy Neutrinos in the Decay π→eν\pi\rightarrow e\nu

A search for massive neutrinos has been made in the decay $\pi\rightarrow e^+ \nu$. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos ($\pi\rightarrow e^+ \nu_h$). Upper limits (90 \% C.L.) on the neutrino mixing matrix element $|U_{ei}|^2$ in the neutrino mass region 60--135 MeV/$c^2$ were set, which are %representing an order of magnitude improvement over previous results