Rational Hausdorff Divisors: a New approach to the Approximate Parametrization of Curves

In this paper we introduce the notion of rational Hausdorff divisor, we analyze the dimension and irreducibility of its associated linear system of curves, and we prove that all irreducible real curves belonging to the linear system are rational and are at finite Hausdorff distance among them. As a consequence, we provide a projective linear subspace where all (irreducible) elements are solutions to the approximate parametrization problem for a given algebraic plane curve. Furthermore, we identify the linear system with a plane curve that is shown to be rational and we develop algorithms to parametrize it analyzing its fields of parametrization. Therefore, we present a generic answer to the approximate parametrization problem. In addition, we introduce the notion of Hausdorff curve, and we prove that every irreducible Hausdorff curve can always be parametrized with a generic rational parametrization having coefficients depending on as many parameters as the degree of the input curve

Organizational readiness for wellness promotion - a survey of 100 African American church leaders in South Los Angeles.

BackgroundChurches are an important asset and a trusted resource in the African American community. We needed a better understanding of their readiness to engage in health promotion before launching a large-scale health promotion effort in partnership with South Los Angeles churches.MethodsIn 2017, we conducted surveys with leaders of 100 churches. Surveys were conducted face-to-face (32%) or by telephone (68%) with senior pastors (one per church) and lasted on average 48 min. We compared small (less than 50 active members), medium (50-99 active members) and large churches (at least 100 active members), and assessed which church characteristics were associated with the implementation of wellness activities.ResultsMedium and large churches conducted significantly more wellness activities than small churches and were more likely to have wellness champions and health policies. Regardless of church size, insufficient budget was the most commonly cited barrier to implement wellness activities (85%). A substantial proportion of churches was not sure how to implement wellness activities (61%) and lacked volunteers (58%). Forty-five percent of the variation in the number of wellness activities in the last 12 months was explained by church characteristics, such as size of congregation, number of paid staff, leadership engagement, having a wellness ministry and barriers.ConclusionsMany churches in South Los Angeles are actively engaged in health promotion activities, despite a general lack of resources. We recommend a comprehensive assessment of church characteristics in intervention studies to enable the use of strategies (e.g., stratification by size) that reduce imbalances that could mask or magnify study outcomes. Our data provide empirical support for the inner settings construct of the Consolidated Framework for Implementation Research in the context of health promotion in African American churches

ESCENARIO LABORAL DEL DECANATO DE CIENCIAS ECON 3MICAS Y EMPRESARIALES DE LA UCLA DESDE LA PERSPECTIVA DE LA CAPACITACI 3N DEL PERSONAL DE APOYO.

En el presente art\uedculo se analiza el escenario laboral del personal de apoyo del Decanato de Ciencias Econ\uf3micas y Empresariales de la Universidad Centroccidental "Lisandro Alvarado", con la finalidad de conocer el proceso de capacitaci\uf3n. Se desarroll\uf3 en dos fases, un diagn\uf3stico con la opini\uf3n de tres grupos inherentes a la capacitaci\uf3n y otra de contraste a igualdad de t\ue9rminos, generando una matriz que permiti\uf3 describir el escenario laboral del decanato. La poblaci\uf3n estuvo conformada por 36 sujetos, a quienes se les aplic\uf3 un instrumento previamente validado y su confiabilidad se determin\uf3 por medio del m\ue9todo de Alfa de Cr\uf6nbach. Los resultados evidenciaron que los cursos de formaci\uf3n recibidos por el personal administrativo de apoyo no son suficientes, que no existe un instrumento para conocer sus necesidades de capacitaci\uf3n, carencia de periodicidad para aplicar la capacitaci\uf3n al personal, ni responsabilidad de realizar medici\uf3n de desempe\uf1o en los diferentes cargos, que el trabajador no recibe una adecuada capacitaci\uf3n profesional en atenci\uf3n a los objetivos del \ue1rea donde se va a desenvolver. Se concluye que existe una necesidad apremiante de instrumentar innovaciones de capacitaci\uf3n que partan de la relaci\uf3n entre las necesidades de cada Decanato. Palabras Clave: Capital humano, capacitaci\uf3n, competencias, escenario laboral. ABSTRACT This article analyzes the labor scenario of the support staff of the Faculty of Economics and Business Sciences of the "Lisandro Alvarado" Centroccidental University, in order to know the training process. It was developed in two phases, a diagnosis with the opinion of three groups inherent to the training and another one in equal terms as a contrast, generating a matrix that allowed to describe the work scenario in the Faculty. Population included 36 subjects, who were given a previously validated instrument and their reliability was determined using the Cr\uf6nbach Alpha method. The results showed that the training courses received by support staff are not sufficient, there is no instrument to know their training needs, there is no training periodicity, nor measurement responsibility of performance in positions, and employees do not receive an adequate professional training in attention to the objectives of the area where it is going to develop. It is concluded that there is an urgent need to implement training innovations based on the needs of each Faculty. Keywords: Human capital, training, skills, labor scenario. RESUMO Neste artigo \ue9 analisado o cen\ue1rio de trabalho do pessoal de apoio da faculdade de ci\ueancias econ\uf4micas e empresariais da Universidade Centroccidental "Lisandro Alvarado" (UCLA), com o fim de conhecer o processo de forma\ue7\ue3o. O trabalho foi desenvolvido em duas fases, uma de diagn\uf3stico com a opini\ue3o de tr\ueas grupos inerente \ue0 forma\ue7\ue3o e outra de contraste com igualdade de condi\ue7\uf5es, gerando uma matriz que permitiu descrever o cen\ue1rio de trabalho da faculdade. A popula\ue7\ue3o esteve conformada de 36 indiv\uedduos aos quais se aplicou um instrumento previamente validado e sua confiabilidade foi determinada pelo m\ue9todo de alfa de Cronbach. Os resultados mostraram que a forma\ue7\ue3o recebida pelo pessoal de apoio administrativo n\ue3o s\ue3o suficientes, que n\ue3o h\ue1 nenhuma ferramenta para determinar as suas necessidades de forma\ue7\ue3o, falta de periodicidade para a implementa\ue7\ue3o da forma\ue7\ue3o do pessoal n\ue3o h\ue1 responsabilidade de realizar a medi\ue7\ue3o do desempenho nas diferentes fun\ue7\uf5es dos trabalhadores e n\ue3o recebem forma\ue7\ue3o profissional adequada aos objetivos da \ue1rea onde eles v\ue3o se desenvolver. Concluiu-se que h\ue1 uma necessidade premente para implementar inova\ue7\uf5es de forma\ue7\ue3o que se originem da rela\ue7\ue3o entre as necessidades de cada faculdade. Palavras-chave: Capital humano, habilidades, treinamento. <br

Internal and relative motions of the Taurus and Ophiuchus star-forming regions

We investigate the internal and relative motions of the Taurus and Ophiuchus star-forming regions using a sample of young stars with accurately measured radial velocities and proper motions. We find no evidence for expansion or contraction of the Taurus complex, but a clear indication for a global rotation, resulting in velocity gradients, this suggests a common origin, possibly related to that of Gould's Belt.Comment: 2 figure

Chemical analysis by X-ray spectroscopy near phase transitions in the solid state

The methods discussed in this work show that the types of changes which may be observed, by precise XAS measurements of Absorbance A versus temperature, across a phase transition are: the changes in the relaxation time of the final states due to fluctuations near a phase transition; the detection of the anomalous Bragg condition coupled to phonon modes XAS enhancement that identifies the temperature interval where the phonon modes are active, the symmetry changes which introduce new allowed transitions to finite states below an element edge, near Tc indicate what symmetry changes occur, and the method of XTDAFST0 = XAFS(T) - XAFS(T0), allows the precise measurement of the progressive changes in the Debye-Waller factor versus T near a phase transition, and identify (when no other structural changes occur, except in the vibrational modes of a specific bond) the bond responsible for the transition. The methods have been applied to the superconducting transition in layer cuprates and the metal to insulator transition in NiS2-xSex

The investigation of EPR paramagnetic probe line width and shape temperature dependence in high-temperature superconductors of Bi–Pb–Sr–Ca–Cu–O system

The work is related with the finding out of magnetic phases in strongly anisotropic high-temperature superconductor Bi1,7Pb0,3Sr2Ca2Cu3O10-δ in the temperature region where the superconductor is in the normal state. It was studied the temperature dependence of the paramagnetic probe EPR line width. In the normal state at T\u3eTc near 175 K it was revealed a pick in the temperature dependence of line width. In this region it was observed the time increase of the line width with the characteristic time ~ 17 min. This shows the possibility of magnetic phase formation in this material

Evolution of the spherical cavity radius generated around a subsurface drip emitter

The emitter discharge in subsurface drip irrigation can be affected by soil properties. A positive pressure develops at the emitter outlet where a spherical cavity is assumed to form. In steady-state conditions, the pressure in the soil relates to soil hydraulic properties, the emitter discharge, and the cavity radius. This pressure in the soil is very sensitive to the cavity radius. In this paper, the development of the cavity around the emitter outlet was measured for various emitter discharges in laboratory tests carried out in containers with uniform loamy soils. A trend between soil pressure and emitter discharge was established that illustrates the performance of buried emitters in the field. Its application to the prediction of water distribution in subsurface drip irrigation units and its effect on the estimation of irrigation performance are also shown

An algorithm to parametrize approximately space curves

This is the author’s\ud version of a work that was accepted for publication in\ud Journal of Symbolic Computation. Changes resulting from the publishing\ud process, such as peer review, editing, corrections,\ud structural formatting, and other quality control mechanisms may not be\ud reflected in this document.\ud Changes may have been made to this work since it was submitted for\ud publication.\ud A definitive version was subsequently published in Journal of Symbolic\ud Computation vol. 56 pp. 80-106 (2013).\ud DOI: 10.1016/j.jsc.2013.04.002We present an algorithm that, given a non-rational irreducible\ud real space curve, satisfying certain conditions, computes a rational\ud parametrization of a space curve near the input one. For a given\ud tolerance \epsilon > 0, the algorithm checks whether a planar projection\ud of the given space curve is \epsilon -rational and, in the affirmative\ud case, generates a planar parametrization that is lifted to a space\ud parametrization. This output rational space curve is of the same\ud degree as the input curve, both have the same structure at infinity,\ud and the Hausdorff distance between their real parts is finite.\ud Moreover, in the examples we check that the distance is small.This work has been developed, and partially supported, by the Spanish “Ministerio de Ciencia e\ud Innovación” under the Project MTM2008-04699-C03-01, and by the “Ministerio de Economía y Competitividad”\ud under the project MTM2011-25816-C02-01. All authors belong to the Research Group\ud ASYNACS (Ref. CCEE2011/R34)