A Survey for Spectroscopic Binaries Among Very Low-Mass Stars

We report on the results of a survey for radial velocity variability in a heterogeneous sample of very low-mass stars and brown dwarfs. One distinguishing characteristic of the survey is its timespan, which allows an overlap between spectroscopic binaries and those which can be found by high angular-resolution imaging. We are able to place a new constraint on the total binary fraction in these objects, which suggests that they are more likely the result of extending the same processes at work at higher masses into this mass range, rather than a distinct mode of formation. Our basic result is that there are $6 \pm 2$ out of 53, or $11^{+0.07}_{-0.04}$% spectroscopic binaries in the separation range 0-6 AU, nearly as many as resolved binaries. This leads to an estimate of an upper limit of $26 \pm 10$% for the binary fraction of VLM objects (it is an upper limit because of the possible overlap between the spectroscopic and resolved populations). A reasonable estimate for the very low-mass binary fraction is $20 - 25$%. We consider several possible separation and frequency distributions, including the same one as found for GK stars, a compressed version of that, a version of the compressed distribution truncated at 15 AU, and a theoretical distribution which considers the evaporation of small-N clusters. We conclude that the latter two bracket the observations, which may mean that these systems form with intrinsically smaller separations due to their smaller mass, and then are truncated due to their smaller binding energy. We do not find support for the ``ejection hypothesis'' as their dominant mode of formation, particularly in view of the similarity in the total binary fraction compared with slightly more massive stars, and the difficulty this mechanism has in producing numerous binary systems.Comment: 36 pages, accepted for publication in AJ, abstract shortened for arXiv.or

Evaluation of the anti-angiogenic potential of hydroxytyrosol derivatives

Angiogenesis, a process which allows the formation of new vessels from pre-existing ones, is an essential phenomenon for tumor survival since it allows cancer cells to obtain nutrients and oxygen. This explains the increasing interest showed by many groups of research and pharmaceutical companies to find compounds with potential to disrupt at least one of the steps within the angiogenic process. Hydroxytyrosol (3,4-dihydroxyphenyl ethanol) has been identified as the most important health-related phenolic compound of virgin olive oil because of its pleiotropic effects on multiple targets. In 2012, our group identified hydroxytyrosol as an anti-angiogenic compound able to inhibit several key steps in the angiogenic process. In the present study, the potential effects of six hydroxytyrosol derivatives are tested and compared with those exhibited by hydroxytyrosol by making use of several in vitro and in vivo assays. Results indicate that these are candidate new anti-angiogenic compounds with potential utility in anti-tumor and anti-angiogenic therapies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech [Our experimental work is supported by grants BIO2014-56092-R (MINECO and FEDER) and P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain)]. This communication has the support of a travel grant

Using the strategic relative alignment index for the selection of portfolio projects application to a public Venezuelan Power Corporation

In this paper a new approach that uses the alignment of projects with corporate strategic objectives to prioritize project portfolio in an efficient and reliable way is presented. For this purpose, corporate strategic objectives will be used as prioritization criteria to obtain the Relative Alignment Index (RAI) of each project which indicates how close or far each project is from the strategic objectives of the company. The approach presented uses the Analytic Network Process. This technique allows considering the influences among all the elements within the network, that means, the strategic objectives, and specially the projects within a portfolio. The proposed RAI index helps to select the best strategically aligned projects for the organization. The proposed RAI index and its form of evaluation have not previously been considered in the project portfolio literature until now. The research methodology for the development of RAI is based on a combination of a synthesis of the literature across the diverse fields of project management, project alignment, multicriteria decision methods and a parallel analysis of an industrial case study. The use of the proposed RAI index is demonstrated using a rigorous methodology with acceptable complexity which seeks to assist managers of the National Electricity Corporation of Venezuela, recently founded and composed by 13 merging old companies, both public and private, in their yearly resources' assignment on their projects portfolio. The aim being to determine a projects 'ranking based on their degree of alignment to corporate strategy and on the judgments of a group of experts, such as the management board. The new corporation assumed the challenge of setting strategic directions (Mission, Vision, Values, Strategic objectives, Plans, Programs, etc.) common to all merging companies. This approach with multi-stakeholders support allows managers to strategically allocate resources to each project in a consensual way.García-Melón, M.; Poveda Bautista, R.; Del Valle, JL. (2015). Using the strategic relative alignment index for the selection of portfolio projects application to a public Venezuelan Power Corporation. International Journal of Production Economics. 170:54-66. doi:10.1016/j.ijpe.2015.08.023S546617

Using alignment with corporate strategy for the selection of a project portfolio based on ANP

Trabajo presentado al 14th International Symposium on the Analytic Hierarchy Process celebrado en Washington (US) del 29 de junio al 2 de julio de 2014.In this paper a new approach to prioritize project portfolio in an efficient and reliable way is presented. The research methodology is based on a combination of a synthesis of the literature across the diverse fields of project management, project alignment, multicriteria decision methods and a parallel analysis of an industrial case study. The paper introduces a rigorous methodology with acceptable complexity which seeks to assist managers of the National Electricity Corporation of Venezuela (Corpoelec) in their yearly resources' assignment on their projects portfolio. The aim being to determine the degree of alignment of each project to corporate strategy based on the judgments of a group of experts on the expected contribution of the projects to the business strategic objectives. The model presented can be used both as a descriptive and a prescriptive model. The approach presented uses project prioritization based on the multi-criteria decisionmaking technique called Analytic Network Process. Thus the corporate strategic objectives will be used as prioritization criteria to obtain the Relative Alignment Index (RAI).Peer Reviewe

Antiretroviral Treatment for HIV Elite Controllers?

In most HIV-infected persons, the natural history of untreated infection is one of sustained viremia, progressive CD4 T cell depletion with resultant morbidity and mortality. The advent of effective combination antiretroviral therapy (ART) that controls HIV replication has altered this landscape dramatically. Yet a rare population of HIV-infected persons-elite controllers (EC)-can control HIV replication such that plasma levels of virus are "undetectable" without ART. The EC phenotype is heterogeneous, with some subjects durably controlling the virus-persistent elite controllers-and some eventually losing viral control-transient elite controllers. Overall, EC tend to have robust HIV-specific T cell responses and in some cases, mainly in transient elite controllers, elevated activation and inflammation indices that diminish with ART suggesting that endogenous defenses against this persistent pathogen come at the cost of heightened activation/inflammation. A limited data set suggests that cardiovascular disease risk as well as the occur-rence of other morbid events may be greater in the overall EC population than in treated HIV infection. ART in EC decreases activation indices but does not appear to increase circulating CD4 T cell numbers nor do we know if it alters clinical outcomes. Thus, it is difficult to recommend or discourage a decision to start ART in the EC population but the authors lean toward treatment particularly in those EC whose activation indices are high and those who are progressively losing circulating CD4 T cell numbers. Biomarkers that can reliably predict loss of virologic control and immune failure are needed

Identificación de cepas de micoplasma aviar y estudio serológico en la Sabana de Bogotá.

Con el objeto de emplear técnicas para aislamiento e identificación de cepas de micoplasma aviar en aves de la Sabana de Bogotá; estandarización de técnicas para el cultivo, adaptables a nuestro medio y determinación de niveles de infección a nivel de granjas utilizando métodos serológicos, se efectuaron muestreos de casos clínicos y muestreos serológicos en diferentes granjas avícolas de la Sabana de Bogotá. Las muestras fueron cultivadas en medio Frey modificado y luego identificadas por el método de inmunofluorescencia directa. Ocho cepas de M. gallisepticum fueron aisladas e identificadas de muestras de sacos aéreos en aves necropsiadas. De un total de 1.200 sueros sometidos a las pruebas serológicas de aglutinación en placa e inhibición de la hemaglutinación, 54.6 por ciento resultaron positivas a M. gallisepticum, mientras que a la prueba de inhibición de la hemaglutinación 51.08 por ciento de las muestras resultaron positivas, 22.5 por ciento sospechosas y 26.4 por ciento negativas. Para M. Synoviae en la prueba de aglutinación en placa se encontró un 26.1 por ciento de positividad y en la prueba de inhibición de la hemaglutinación 31.3 por ciento de los sueros fueron positivos, 13.8 por ciento sospechosos y 54.8 por ciento negativosAviculturaMaestría en CienciasMaestrí

Estudio sobre el curso de reforzamiento en matemática de la prueba de capacidades académicas del Centro Regional Universitario de San Miguelito en el 2017

Esta investigación, analiza el programa del curso de reforzamiento para la Prueba de Capacidades Académicas, relacionada específicamente con el área de Matemática en el Centro Regional Universitario de San Miguelito, así como la metodología que emplean los docentes cuando imparten dicho curso de reforzamiento. Al finalizar la investigación nos encontramos con el hecho de que la mayoría de los docentes que han impartido este curso de reforzamiento, afirman que la metodología y el programa necesitan modificaciones más acordes con la realidad en la que se imparte dicho curso y, por otra parte, los estudiantes muestran un alto grado de apatía y poca habilidad para desarrollar problemas en donde estén involucrados los conocimientos Matemáticos. La investigación la hemos dividido en cinco capítulos organizados de la siguiente manera: En el capítulo uno, la parte introductoria del problema a investigar; el capítulo dos, trata de la sustentación teórica y conceptual en la que se fundamenta la investigación; en el capítulo tres, se expone la metodología empleada en el estudio; los resultados y el análisis del proyecto se encuentran expresados en el capítulo cuatro y; finalmente el capítulo cinco, presenta una propuesta del programa que se debe emplear en el curso de reforzamiento

Analysis of effective resistance calculation methods and their effect on modelling evapotranspiration in two different patches of vegetation in semi-arid SE Spain

Effective parameters are of major importance in modelling surface fluxes at different scales of spatial heterogeneity. Different ways to obtain these effective parameters for their use in meso-scale and GCM models have been studied. This paper deals with patch-scale heterogeneity, where effective resistances were calculated in two patches with different vegetation (Retama sphaerocarpa (L.) Boiss shrubs, and herbaceous plants) using different methods: aggregating soil and plant resistances in parallel, in series or by an average of both. Effective aerodynamic resistance was also calculated directly from patch fluxes. To assess the validity of the different methods used, the Penman-Monteith equation was used with effective resistances to estimate the total λE for each patch. The λE estimates found for each patch were compared to Eddy Covariance system measurements. Results showed that for effective surface resistances, parallel aggregation of soil and plant resistances led to λE estimates closer to the measured λE in both patches (differences of around 10%). Results for effective aerodynamic resistances differed depending on the patch considered and the method used to calculate them. The use of effective aerodynamic resistances calculated from fluxes provided less accurate estimates of λE compared to the measured values, than the use of effective aerodynamic resistances aggregated from soil and plant resistances. The results reported in this paper show that the best way of aggregating soil and plant resistances depends on the type of resistance, and the type of vegetation in the patch.This work received financial support from several different research projects: the PROBASE (ref.: CGL2006-11619/HID) and CANOA (ref.: CGL2004-04919-C02-01/HID) projects funded by the Spanish Ministry of Education and Science; and the BACAEMA (“Balance de carbono y de agua en ecosistemas de matorral mediterráneo en Andalucía: Efecto del cambio climático”, RNM-332) and CAMBIO (“Efectos del cambio global sobre la biodiversidad y el funcionamiento ecosistémico mediante la identificación de áreas sensibles y de referencia en el SE ibérico”, RNM 1280) projects funded by the regional government Junta de Andalucía. The first author enjoyed a pre-doctoral grant from the Spanish Ministry of Science and Technology

Route to turbulence in a trapped Bose-Einstein condensate

We have studied a Bose-Einstein condensate of $^{87}Rb$ atoms under an oscillatory excitation. For a fixed frequency of excitation, we have explored how the values of amplitude and time of excitation must be combined in order to produce quantum turbulence in the condensate. Depending on the combination of these parameters different behaviors are observed in the sample. For the lowest values of time and amplitude of excitation, we observe a bending of the main axis of the cloud. Increasing the amplitude of excitation we observe an increasing number of vortices. The vortex state can evolve into the turbulent regime if the parameters of excitation are driven up to a certain set of combinations. If the value of the parameters of these combinations is exceeded, all vorticity disappears and the condensate enters into a different regime which we have identified as the granular phase. Our results are summarized in a diagram of amplitude versus time of excitation in which the different structures can be identified. We also present numerical simulations of the Gross-Pitaevskii equation which support our observations.Comment: 6 pages, 3 figure