Vacuum field energy and spontaneous emission in anomalously dispersive cavities

Anomalously dispersive cavities, particularly white light cavities, may have larger bandwidth to finesse ratios than their normally dispersive counterparts. Partly for this reason, their use has been proposed for use in LIGO-like gravity wave detectors and in ring-laser gyroscopes. In this paper we analyze the quantum noise associated with anomalously dispersive cavity modes. The vacuum field energy associated with a particular cavity mode is proportional to the cavity-averaged group velocity of that mode. For anomalously dispersive cavities with group index values between 1 and 0, this means that the total vacuum field energy associated with a particular cavity mode must exceed $\hbar \omega/2$. For white light cavities in particular, the group index approaches zero and the vacuum field energy of a particular spatial mode may be significantly enhanced. We predict enhanced spontaneous emission rates into anomalously dispersive cavity modes and broadened laser linewidths when the linewidth of intracavity emitters is broader than the cavity linewidth.Comment: 9 pages, 4 figure

EVALUATION OF THE DELTA STATE SKILLS TRAINING AND ENTREPRENEURSHIP PROGRAMME (STEP)

This study evaluated the extent to which the goals of the Delta State Skills Training and Entrepreneurship Programme (STEP) have been achieved. Three research questions guided the study. The population of the study comprised 4,559 beneficiaries. A sample size of 1,000 beneficiaries was selected through proportionate stratified and convenience sampling techniques. A questionnaire was used to collect data. Experts’ judgement was used to validate the instrument. The test-retest method of reliability was used to determine the reliability of the instrument, with a coefficient of 0.82. Frequency and percentage were used to analyse the data. The findings of the study revealed that STEP has trained beneficiaries in the following skill options: Fashion design, Catering, Hairdressing, Make-up, Fishery, Decoration and event management, Electrical installation and repairs, Welding and fabrication, ICT and Farming; all the 1000 participants evaluated have established their own enterprises, indicating a 100% goal achievement; and that majority of the beneficiaries have employed other youths after graduating from the programme. The study recommended amongst others that the program be expanded to accommodate more economically viable skills and vocations, including commerce/trade apprenticeship.  Article visualizations

On the Instanton Contributions to the Masses and Couplings of E6E_6 Singlets

We consider the gauge neutral matter in the low--energy effective action for string theory compactification on a \cym\ with $(2,2)$ world--sheet supersymmetry. At the classical level these states (the \sing's of $E_6$) correspond to the cohomology group H^1(\M,{\rm End}\>T). We examine the first order contribution of instantons to the mass matrix of these particles. In principle, these corrections depend on the \K\ parameters $t_i$ through factors of the form e^{2\p i t_i} and also depend on the complex structure parameters. For simplicity we consider in greatest detail the quintic threefold \cp4[5]. It follows on general grounds that the total mass is often, and perhaps always, zero. The contribution of individual instantons is however nonzero and the contribution of a given instanton may develop poles associated with instantons coalescing for certain values of the complex structure. This can happen when the underlying \cym\ is smooth. Hence these poles must cancel between the coalescing instantons in order that the superpotential be finite. We examine also the \Y\ couplings involving neutral matter \ysing\ and neutral and charged fields \ymix, which have been little investigated even though they are of phenomenological interest. We study the general conditions under which these couplings vanish classically. We also calculate the first--order world--sheet instanton correction to these couplings and argue that these also vanish.Comment: 40 pages, plain TeX with epsf, one uuencoded figur

Perturbative Quantum (In)equivalence of Dual σ\sigma Models in 22 dimensions

Various examples of target space duality transformations are investigated up to two loop order in perturbation theory. Our results show that when using the tree level (`naive') transformation rules the dual theories are in general {\it inequivalent} at two loops to the original ones, (both for the Abelian and the non Abelian duality).Comment: 11 pages, Latex, uses espcrc2.st

First record of promops davisoni (Thomas, 1921) (chiroptera, molossidae) from Chile and a description of its echolocation calls

[Primer registro de promops davisoni (Thomas, 1921) (chiroptera, molossidae) en Chile, y des-cripción de sus llamadas de ecolocación]Few studies have been conducted on the bat fauna of the Arica and Parinacota region, northern Chile. The genus Promops (Gervais, 1855) is a poorly known group of molossid bats, with three species widely distributed in Central and South America. We report for the first time the species Promops davisoni in Chile. Identification was based on echolocation calls obtained at the Azapa and Lluta valleys and compared to reference calls from Tacna, Peru. We report the species as far as 127 km south of the previous published southernmost record in Pampa Alta, Peru. In addition we obtained an individual found at the Anzota caves, near the city of Arica. The species is found on the coast and in the fluvial valleys of Northern Chile, with altitudes ranging from sea level to 822 m a.s.l. We propose that the distribution of P. davisoni may extend further south, to the locality of Tana in the Tarapacá region, based on the capacity of the species to cross distances of over 100 km over large desert areas. With this species, we increase the known bat fauna of Chile to 14 species, and the bat fauna of the Arica and Parinacota region to nine species. © SAREM, 2018.Peer reviewe

Evaluación genética del ganado criollo y sus cruces en Colombia

Colombia has seven Criollo breed s of cattle adapted to tropical conditions, with a total number of pure breds of about 18.000, and about 50.000 cattle if Criollo crossbreds are also considered. The 1986 Livestock Development Project suggested increasing their numbers and developing animal improvement programs at a farm level. These goals can be achieved through the development of a national genetic evaluation program involving all Criollo breeds and their cross breds. The basic population and data structures that would allow the realization of a national genetic evaluation are presented and discussed in terms of the Colombian situation. Current unibreed and multibreed linear methodology, and computational procedures, are discussed, and computer software programs are suggested. A general strategy to develop a National Genetic Evaluation Program is outlined, and specific points discussed in further detail from a Colombian perspective. The implementation of a large national genetic evaluation program will not only benefit the Criollo breeds and their crossbreds, but it can serve as a model for the genetic evaluation of all cattle breed s and their cross breds in Colombia.Colombia posee siete razas de bovinos criollos adaptadas a las condiciones tropicales; el número total de animales puros es menor de 18.000, aunque si se consideran los animales criollos cruzados, dicho censo asciende a 50.000 animales aproximadamente. El Proyecto de Desarrollo Ganadero de 1986 sugirió aumentar su número y desarrollar planes de mejoramiento a nivel de finca. Estos objetivos se pueden lograr mediante un programa de evaluación genética nacional que incluya todas las razas criollas y sus cruces. El presente artículo presenta las estructuras básicas de las poblaciones y de los datos, a partir de los cuales es posible realizar una evaluación genética nacional, la cual se analiza en términos de la actual situación colombiana. Se discuten además, métodos lineales y procedimientos computacionales unirraciales y multirraciales para su manejo, y se sugiere el uso de programas de computación. Así mismo, se plantea una estrategia general para desarrollar dicho Programa Nacional de Evaluación Genética, enfatizando en algunos aspectos específicos desde el punto de vista colombiano. La implementación de dicho programa beneficiaría la conservación y el desarrollo de las razas criollas y de sus cruces, además de servir como modelo para desarrollar de manera sistemática la evaluación genética de los bovinos colombianos. 

ArgoNeuT and the Neutrino-Argon Charged Current Quasi-Elastic Cross Section

ArgoNeuT, a Liquid Argon Time Projection Chamber in the NuMI beamline at Fermilab, has recently collected thousands of neutrino and anti-neutrino events between 0.1 and 10 GeV. The experiment will, among other things, measure the cross section of the neutrino and anti-neutrino Charged Current Quasi-Elastic interaction and analyze the vertex activity associated with such events. These topics are discussed along with ArgoNeuT's automated reconstruction software, currently capable of fully reconstructing the muon and finding the event vertex in neutrino interactions.Comment: 6 pages, 4 figures, presented at the International Nuclear Physics Conference, Vancouver, Canada, July 4-9, 2010, to be published in Journal of Physics: Conference Series (JPCS

Dressing Cosets

The account of the Poisson-Lie T-duality is presented for the case when the action of the duality group on a target is not free. At the same time a generalization of the picture is given when the duality group does not even act on \si-model targets but only on their phase spaces. The outcome is a huge class of dualizable targets generically having no local isometries or Poisson-Lie symmetries whatsoever.Comment: 11 pages, LaTe

Open Strings and D-branes in WZNW model

An abundance of the Poisson-Lie symmetries of the WZNW models is uncovered. They give rise, via the Poisson-Lie $T$-duality, to a rich structure of the dual pairs of $D$-branes configurations in group manifolds. The $D$-branes are characterized by their shapes and certain two-forms living on them. The WZNW path integral for the interacting $D$-branes diagrams is unambiguously defined if the two-form on the $D$-brane and the WZNW three-form on the group form an integer-valued cocycle in the relative singular cohomology of the group manifold with respect to its $D$-brane submanifold. An example of the $SU(N)$ WZNW model is studied in some detail.Comment: 28 pages, LaTe

SAÚDE MENTAL EM JOVENS UNIVERSITÁRIOS: RELATOS DA INFÂNCIA

Este trabajo muestra los primeros resultados de una investigación que busca atender una seria problemática que asola a la universidad pública, los casos de suicidio y trastornos mentales en jóvenes universitarios. Se espera avanzar en el conocimiento sobre el suicidio y problemáticas psicológicas o psiquiátricas a través de la psicología clínica y en perspectiva interdisciplinaria con la fenomenología de la vida, además de las ya existentes en el medio científico. El método es esencialmente cualitativo, de observación de casos e interlocución en la acogida a los estudiantes. La metodología fenomenológica en la clínica posibilita conocer el fenómeno que se presenta en los diálogos con los estudiantes y la comunidad tal como se manifiestan. Los resultados iniciales de 17 jóvenes nos muestran que traen quejas de ansiedad, depresión, uso de medicamentos, soledad, futuro incierto, necesidad de psicoterapia a medio y largo plazo. No hay quejas significativas en relación a las presiones universitarias o políticas universitarias, pero lo que llama la atención es la expresión de sus historias relacionadas a la infancia y la preadolescencia. Los relatos de la infancia no están en el pasado, pero todavía presentes en las vivencias cotidianas de los jóvenes universitarios y nos ayudan a comprender y cuidar de los aspectos psicológicos y comunitarios en la formación universitaria