Mejoras a las pruebas eléctricas utilizadas en la validación de ChipSets.

Proyecto de Graduación (Licenciatura en Ingeniería Electrónica). Instituto Tecnológico de Costa Rica. Escuela de Ingeniería Electrónica, 2007.En el departamento Ingeniería del Producto específicamente en la plataforma de validación de ChipSets de la empresa Componentes Intel de Costa Rica no se contaba con la información suficiente para realizar un análisis del porqué se están dando ciertas fallas en la línea de producción, así como si la falla que se presentaba se debía a la máquina de pruebas o en causa propia de la unidad sometida a prueba. La principal consecuencia de que este problema no fuera resuelto es que se seguirían clasificando unidades en buen estado como unidades defectuosas. Además el origen de la falla sería una incógnita debido a la carencia de información necesaria. Finalmente el descartar unidades en buen estado hace que decaiga el índice de productividad del sitio, repercutiendo en la imagen y la confiabilidad por parte de la gerencia internacional. Los beneficios de la solución al problema planteado se notan en la confiabilidad sobre los resultados obtenidos en las pruebas, además de la retroalimentación que se obtenida al contar con información específica de la causa de la falla, de esta manera se permite tener mas eficiencia y se es mas certero a la hora de implementar las acciones correctivas al proceso. Para darle solución al problema se elaboraron una serie de diseños metodológicos de pruebas que cumplen con los requisitos estipulados para no afectar al producto y simultáneamente generar mayor información para el mantenimiento del módulo, así como acciones correctivas de algunas de las causas de error más comunes.Componentes Intel Costa Ric

Heat tolerance of two hair sheep breeds in the Federal District, Brazil

O objetivo deste estudo foi avaliar efeitos da temperatura ambiental sobre características fisiológicas de ovinos, no Distrito Federal. Foram selecionados dois grupos de 25 fêmeas vazias ou prenhas das raças Morada Nova e Santa Inês com idade variando entre dois e quatro anos. As fêmeas tiveram seus dados coletados seis vezes entre os meses de fevereiro e julho. As medições incluíram o peso vivo ( PV) (kg), a temperatura retal (TR), a freqüência respiratória (FR) e o batimento cardíaco (BC), às 8 e 14h, depois de expostas ao sol por um período de seis horas. Foram utilizados os procedimentos GLM, CORR e PRINCOMP do SAS e, para determinar grupamento e dissimilaridade, utilizou-se o programa GENES. Observaram-se grupos de alta e baixa resistência a ação do efeito calórico. As médias dos grupos às 14 hs foram: TR: 38,8 e 38,7°C; FR: 23,4 e 22,8 bat./min. e BC: 99,9 e 94,0 bat./min. para os animais das raças Morada Nova e Santa Inês, respectivamente. Houve ainda diferenças significativas entre matrizes não paridas e as paridas no período estudado, sendo maiores para não paridas: TR: 38,78 e 38,52°C; BC:23,13 e 22,82 bat./min.; FR: 96,98 e 96,36 bat./min., respectivamente. Os animais expostos ao sol pelo período de seis horas apresentaram resposta significativa ao estresse calórico, expresso pelo aumento da temperatura retal e pelo aumento no ritmo dos batimentos cardíacos e na freqüência respiratória. Os resultados obtidos permitiram estabelecer grupos de animais com maior e menor resistência às variações climáticas, ensejando a possibilidade de utilizar esses dados para seleção de animais em trabalhos de melhoramento.The objective of this study was to evaluate the effect of increased environmental temperature on physiological traits of Morada Nova (MN) and Santa Ines (SI) sheep breeds in the Federal District, Brazil. Two groups (25 MN and 25 SI) were selected for study and included both pregnant (EP) and non-pregnant (EPN) ewes, aged betwen 2 and 4 years. The fifty ewes were recorded, once a month, for six months, at 8 am and 2 pm, and measurements included body weight (W), RT (Rectal Temperature), RR (Respiration rate), and CR (Cardiac Rate) were analyzed using SAS (GLM, CORR, PRINCOMP procedures) and the program GENES. The differences between the two breeds were: RT: 38.8 and 38.7°C; RR: 23.4 and 22.8 (rate/min.); CR: 99.9 and 94.0 (rate/min.), for Morada Nova and Santa Ines breeds, respectively. Difference between non-pregnant and pregnant ewes were: RT: 38.78 and 38.52°C; RR: 23.13 and 22.82 (Rate/min); CR: 96.98 and 96.36 (Rate/min), respectively. Differences between breeds were significant, as were differences between animals within groups. It was therefore possible therefore to identify animals within a breed more or less resitant to the climate conditions. This information may be used in future breeding programs

Estimation of genetic and phenotypic parameters for brazilian hair sheep in central Brazil

O objetivo deste trabalho foi estimar efeitos genéticos e fenotípicos na criação de ovinos deslanados e mestiços em um criatório no Distrito Federal. Foram analisados os efeitos de sexo, tipo de parto, mês e ano de nascimento sobre peso ao nascer, aos 30, 120 e 210 dias de idade, intervalo de partos (IDP) e idade ao primeiro parto (IPP) de 2337 nascimentos / parições em um rebanho comercial para produção de carne, das raças Morada Nova (MN), Santa Inês (SI) e mestiços Texel x Morada Nova (T x MN), controlado durante 14 anos (1986 a 1999). Os dados da raça MN foram analisados usando um Modelo Animal Univariado no programa MTDFREML para determinar herdabilidade e repetibilidade bem como correlações genéticas e fenotípicas entre as características. O número médio de crias por ovelha foi de 1,25 cordeiros. Os nascimentos ocorreram durante todo o ano, porém com maior índice de cordeiros nascidos (77%), entre os meses de março a setembro, indicando possível influência da extensão do dia ou disponibilidade de alimentação sobre a eficiência reprodutiva. As herdabilidades diretas para peso ao nascer, pesos com 30, 120 e 210 dias foram de 0,15; 0,11; 0,07; e 0,21, respectivamente, para a raça Morada Nova. As correlações genéticas entre os pesos variaram de 0,19 a 0,64. A herdabilidade para intervalo de partos foi de 0,17 e de 0,93 para número de crias. Os efeitos da raça e do peso ao nascer foram altamente significativos, para todos os pesos estudados. O tipo de parto influenciou o peso ao nascer e aos 30 e 210 dias. Os efeitos do número de partos e do mês de nascimento mostraram influências significativas sobre as características avaliadas.This study aims to estimate genetic and phenotypic parameters for the Morada Nova, Santa Inês e crossbred Texel x Morada Nova in Federal District of Brazil. Data were available on 2337 lambings over a period of 14 years (1986 to 1999) from a commercial holding for meat production. The herd had no fixed breeding season. The effects of sex, number of lambs per lambing, month and year of lambing were determined for weights at birth, 30, 120 and 210 days of age as well as lambing interval and age at first lambing using analysis of variance procedures in the SAS program. Heritability, repeatability as well as genetic and phenotypic correlations for the Morada Nova sheep in the herd were estimated using MTDFREML. The generation interval was 952 days, with a mean litter size of 1.25 lambs. Lambings were distributed throughout the year, but 77% occurred between March and September, indicating a possible influence of day length or food availability on reproductive traits. Direct heritabilities for birth weight, weight at 30, 120 and 210 days were, respectively, 0.15, 0.11, 0.07, and 0.21 for Morada Nova sheep. The correlations between these traits were positive (0.19 at 0.64). The heritability for lambing interval was 0.17 and 0.93 for number of lambs per litter. The results indicate that the breed and birth weight were highly significant for all weights studied. Lambing number and birth month affect all the traits examined

Consequences of habitat fragmentation on the reproductive success of two Tillandsia species with contrasting life history strategies

Fragmentation of natural habitats generally has negative effects on the reproductive success of many plant species; however, little is known about epiphytic plants. We assessed the impact of forest fragmentation on plant pollinator interactions and female reproductive success in two epiphytic Tillandsia species with contrasting life history strategies (polycarpic and monocarpic) in Chamela, Jalisco, Mexico, over three consecutive years. Hummingbirds were the major pollinators of both species and pollinator visitation rates were similar between habitat conditions. In contrast, the composition and frequency of floral visitors significantly varied between habitat conditions in polycarpic and self-incompatible T. intermedia but not in monocarpic self-compatible T. makoyana. There were no differences between continuous and fragmented habitats in fruit set in either species, but T. makoyana had a lower seed set in fragmented than in continuous forests. In contrast, T. intermedia had similar seed set in both forest conditions. These results indicate that pollinators were effective under both fragmented and continuous habitats, possibly because the major pollinators are hummingbird species capable of moving across open spaces and human-modified habitats. However, the lower seed set of T. makoyana under fragmented conditions suggests that the amount and quality of pollen deposited onto stigmas may differ between habitat conditions. Alternatively, changes in resource availability may also cause reductions in seed production in fragmented habitats. This study adds to the limited information on the effects of habitat fragmentation on the reproductive success of epiphytic plants, showing that even related congeneric species may exhibit different responses to human disturbance. Plant reproductive systems, along with changes in pollinator communities associated with habitat fragmentation, may have yet undocumented consequences on gene flow, levels of inbreeding and progeny quality of dry forest tillandsias.Fil: Sáyago, Roberto. Universidad Nacional Autónoma de México; México. Universidad Autonoma de Guerrero; MéxicoFil: Quesada, Mauricio. Universidad Autonoma de Guerrero; México. Universidad Nacional Autónoma de México; MéxicoFil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lopezaraiza-Mikel, Martha. Universidad Nacional Autónoma de México; México. Universidad Autonoma de Guerrero; MéxicoFil: Martén-Rodríguez, Silvana. Universidad Nacional Autónoma de México; Méxic

A global review of pollination syndromes: a response to ollerton et al. 2015

In a recent literature review, we demonstrated that the evolution of floral traits is driven by adaptation to the most effective pollinators. In a critique of this study, Ollerton et al. 2015 claimed there were apparent flaws with data collection, analyses and interpretation of results. We disagree since many of OLT´s observations and recommendations are subjective and overlook basic aspects of meta-analysis. Here, we address the main criticisms of Ollerton et al 2015.Fil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Martén Rodríguez, Silvia . Universidad Nacional Autónoma de México; México. Instituto de Ecología; MéxicoFil: Avila Sakar, Germán. The University of Winnipeg; CanadáFil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Lopezaraiza Mikel, Martha. Universidad Autónoma de Guerrero; MéxicoFil: Quesada, Mauricio. Universidad Nacional Autónoma de México; Méxic

The role of tropical dry forests for biodiversity, carbon and water conservation in the neotropics: lessons learned and opportunities for its sustainable management

In this paper, we provide a comprehensive evaluation of the current regional literature associated with tropical dry forest (TDF) along three main axes: biodiversity, carbon and water conservation in the neotropics. Our analysis provides three key findings: (1) from the biodiversity point of view, we document that high degrees of endemism, diversity of plant life forms and ecophysiological types as key elements for their conservation across the Americas, (2) from the carbon storage point of view, we found that if the world’s TDFs were restored they whole ecosystem would comprise 22 Pg of carbon in aboveground biomass. In the Americas alone, TDF restoration could potentially add 8 Pg of carbon to the potential total ecosystem carbon stock, (3) we found that at least 66 % of water reservoirs in the neotropics are located within dry forest ecoregions; therefore, the conservation of the quality of freshwater sources for human consumption in the neotropics is directly dependent on the sustainable management of TDF-dominated landscapes. In this paper, we stress that advocacy for conservation and sustainable management of TDF will benefit from integrating it’s value in biophysical terms (e.g. carbon, biodiversity) with key ecosystem services and uses (e.g. its impact on hydrological dynamics and its potential for fostering ecotourism initiatives and entrepreneurship). By doing this, support and awareness could be wider and more effective in the long term, especially from national and local communities. © 2014, Springer-Verlag Berlin Heidelberg

A scientific note on the first record of nesting sites of Peponapis crassidentata (Hymenoptera: Apidae)

Fil: Delgado Carrillo, Oliverio. Escuela Nacional de Estudios Superiores, Morelia, Mexi; México. Universidad Nacional Autónoma de México; MéxicoFil: Lopezaraiza Mikel, Martha. Universidad Autonoma de Guerrero; México. Universidad Nacional Autónoma de México; MéxicoFil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional Autónoma de México; MéxicoFil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional Autónoma de México; MéxicoFil: Lobo, Jorge A.. Universidad de Costa Rica; Costa RicaFil: Quesada, Mauricio. Universidad Nacional Autónoma de México; Méxic

Pollination Syndromes: A Global Pattern of Convergent Evolution Driven by the Most Effective Pollinator

Convergent evolution of floral traits driven by pollinators has resulted in fl oral syndromes shared among different plant lineages. However, the flowers of many plant species are often visited by different pollinator groups, which apparently contradict the idea of syndromes. Here, we demonstrate that the most efficient pollinators consistently correspond to the ones predicted by the syndrome, and the predictive accuracy of the syndrome tends to be higher for species pollinated exclusively by one functional group than for species pollinated by more than one functional group. Secondary pollinator functional groups affected deferentially the relative efficiency of the primary pollinator depending of the syndrome. The most frequent secondary pollinator group of a given syndrome is also the least efficient one. Floral symmetry did not influence predictability of pollination syndromes. Except for the bee-syndrome plants, pollination syndromes were more effective on plants that depend strongly on animal pollination than on less dependent plants. Last, effective pollinators for each fl oral syndrome were better predicted for plants from tropical regions, particularly for the bat, bee, and bird syndromes. Our results have implications on the effects of global change on floral evolution and suggest that current suites of fl oral traits in most plant species have the potential to adapt to new conditions under changing selective pollination environments.Fil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Martén Rodriguez, Silvana. Instituto de Ecología; MéxicoFil: Lopez Araiza, Martha. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; MéxicoFil: Avila Sakar, German. University Of Winnipeg; CanadáFil: Quesada, Mauricio. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; Méxic

Conservation genetics of relict tropical species of Magnolia (section Macrophylla)

Special conservation efforts should be made for relict species, as they usually have small population sizes and restricted distributions, placing them in critical extinction risk. To achieve conservation, information about genetic diversity distribution is needed. Here, using nine nuclear microsatellites, we analyzed 23 populations of five recently described species of Magnolia distributed in Mexico, which were previously assigned to Magnolia dealbata. We aimed to determine the level of genetic diversity and the distribution of genetic variation and proposed conservation measures. Compared to other endemic and relict species, we found a moderate level of genetic diversity in most populations; however, we identified two populations with no genetic variation. Additionally, we found evidence of positive values of inbreeding likely due to geitonogamy. We found a strong population structure, low effective population size, and no evidence of bottlenecks. Patterns of genetic differentiation did not support the morphological distinction of five species, so we hypothesized that the gene pools may instead represent well-differentiated populations of a single species. We argue that the pattern of genetic differentiation is explained by the natural fragmentation of the cloud forests after glaciation events, and the effects of genetic drift in small populations poorly connected by gene flow. Despite the moderate levels of genetic diversity, special attention is needed to guarantee conservation, with emphasis on the populations in the central region of the country as well as the valuable populations identified in the southwestern region