3,396 research outputs found
Cities in the 21st century: a view from the developing world
In this (introductory) paper, we present i) some basic figures about the rise of cities in the developing world, and ii) the four papers of this special issue. This paper and the other four papers in the issue have the intention to bring to the frontline the reality of cities of the developing world in the 21st century, hoping to motivate further and much needed research.
Ceftiofur-loaded PHBV microparticles: A potential formulation for a long-acting antibiotic to treat animal infections
Indexación: Web of Science; ScieloBackground: The infectious diseases in the livestock breeding industry represent a significant drawback that generates substantial economic loss and have led to the indiscriminate use of antibiotics. The formulation of polymeric microparticles loaded with antibiotics for veterinary use can: reduce the number of required doses; protect the drug from inactivation; and maintain a sustained-release of the antibiotic drug at effective levels. Accomplishing all of these goals would have a significant economic and animal health impact on the livestock breeding industry. Results: In this work, we formulated ceftiofur-loaded PHBV microparticles (PHBV-CEF) with a spherical shape, a smooth surface and diameter sizes between 1.65 and 2.37 μm. The encapsulation efficiency was 39.5 ± 1.1% w/w, and we obtained a sustained release of ceftiofur in PBS-buffer (pH 7.4) over 7 days. The antibacterial activity of ceftiofur was preserved after the encapsulation procedure, and toxicity of PHBV-CEF microparticles evaluated by MTS was represented by an IC50 > 10 mg/mL. Conclusions: Our results suggest that PHBV-CEF particles have a potential application for improving the treatment of infectious diseases in the livestock breeding industry.
Keywords: ceftiofur, drug delivery, livestock breeding industry, PHBV, polymeric microparticle
Predicting RAD-seq marker numbers across the eukaryotic tree of life
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Genome Biology and Evolution 7 (2015): 3207-3225, doi:10.1093/gbe/evv210.High-throughput sequencing of reduced representation libraries obtained through digestion with restriction enzymes—generically known as restriction site associated DNA sequencing (RAD-seq)—is a common strategy to generate genome-wide genotypic and sequence data from eukaryotes. A critical design element of any RAD-seq study is knowledge of the approximate number of genetic markers that can be obtained for a taxon using different restriction enzymes, as this number determines the scope of a project, and ultimately defines its success. This number can only be directly determined if a reference genome sequence is available, or it can be estimated if the genome size and restriction recognition sequence probabilities are known. However, both scenarios are uncommon for nonmodel species. Here, we performed systematic in silico surveys of recognition sequences, for diverse and commonly used type II restriction enzymes across the eukaryotic tree of life. Our observations reveal that recognition sequence frequencies for a given restriction enzyme are strikingly variable among broad eukaryotic taxonomic groups, being largely determined by phylogenetic relatedness. We demonstrate that genome sizes can be predicted from cleavage frequency data obtained with restriction enzymes targeting “neutral” elements. Models based on genomic compositions are also effective tools to accurately calculate probabilities of recognition sequences across taxa, and can be applied to species for which reduced representation data are available (including transcriptomes and neutral RAD-seq data sets). The analytical pipeline developed in this study, PredRAD (https://github.com/phrh/PredRAD), and the resulting databases constitute valuable resources that will help guide the design of any study using RAD-seq or related methods.This research was supported by the Office of Ocean Exploration and Research of the National Oceanic and Atmospheric Administration (NA09OAR4320129 to T.S.); the Division of Ocean Sciences of the National Science Foundation (OCE-1131620 to T.S.); the Astrobiology Science and Technology for Exploring Planets program of the National Aeronautics and Space Administration (NNX09AB76G to T.S.); and the Academic Programs Office (Ocean Ventures Fund to S.H.), the Ocean Exploration Institute (Fellowship support to T.M.S.), and the Ocean Life Institute of the Woods Hole Oceanographic Institution (internal grant to T.M.S. and S.H.)
Culture, Gender, and Labor Force Participation: Evidence from Colombia
This study investigates the impact of integrating gender equality into the
Colombian constitution of 1991 on attitudes towards gender equality,
experiences of gender-based discrimination, and labor market participation.
Using a difference-in-discontinuities framework, we compare individuals exposed
to mandatory high school courses on the Constitution with those who were not
exposed. Our findings show a significant increase in labor market
participation, primarily driven by women. Exposure to these courses also shapes
attitudes towards gender equality, with men demonstrating greater support.
Women report experiencing less gender-based discrimination. Importantly, our
results suggest that women's increased labor market participation is unlikely
due to reduced barriers from male partners. A disparity in opinions regarding
traditional gender norms concerning household domains is observed between men
and women, highlighting an ongoing power struggle within the home. However, the
presence of a younger woman in the household appears to influence men's more
positive view of gender equality, potentially indicating a desire to empower
younger women in their future lives. These findings highlight the crucial role
of cultural shocks and the constitutional inclusion of women's rights in
shaping labor market dynamics
Propuesta de neuromarketing en valores Bancolombia
Actualmente el Marketing a desarrollado conjuntamente con las neurociencia una técnica llamada Neuromarketing, la cual explora el cerebro humano para resolver interrogantes que lleven a las organizaciones a conocer más a profundidad al ser humano, sus gustos, deseos, necesidades y motivadores de compra.
En este documento se presenta como estrategia para una firma comisionista el conocimiento de cada uno de sus clientes para entregar a cada uno de ellos una propuesta de valor diferente, sin dejar a un lado que los valores éticos y morales que se deben aplicar en la utilización de este tipo de tecnologías no pueden dejar a un lado la integridad, libertad y respeto por el cliente
Effects of foliar versus soil water application on ecophysiology, leaf anatomy and growth of pineapple
In the subtropics, pineapple [Ananas comosus (L.) Merr.] can be grown in plastic greenhouses to avoid low temperature, which is the main limiting factor to production outside of the tropics. Foliar water application and subsequent evaporative cooling can help avoid excessive leaf temperatures in greenhouses during the hot seasons. The effects of foliar versus soil irrigation on ecophysiology, leaf anatomy and leaf temperature of pineapple in protected culture were tested to determine if the crop could receive sufficient irrigation to avoid plant stress solely from misting the foliage. Materials and methods - Relative water content, relative chlorophyll content, normalized difference vegetation index, membrane stability, and cross sectional leaf anatomy were measured at periodic intervals. Pineapple plants were subjected to soil irrigation, misting and drought. At the beginning and at the end of the experiment, total leaf area, plant biomass and assimilate partitioning to leaves, stems and roots were measured. Results and discussion - The normalized difference vegetation index revealed differences among treatments after fifteen days without irrigation. Pineapple plants endured thirty days of water stress without membrane damage. Plants irrigated by applying water only to the leaves did not receive adequate water amounts and showed similar signs of drought stress as those of the non-irrigated treatment. Conclusion - Based on ecophysiological, anatomical and growth responses, soil water application alone is sufficient for avoiding water stress and excessively high leaf temperatures of pineapple plants grown in protected culture in the subtropics, whereas only misting the leaves does not provide adequate water supply to prevent water stress.Fil: Demarco, Paula. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Produccion Vegetal.; ArgentinaFil: Gómez Herrera, Melanie Desirée. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Gonzalez, A.M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Alayón Luaces, Paula. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Produccion Vegetal.; Argentin
Dos ensayos sobre discriminación: discriminación salarial y discriminación en acceso al empleo por origen étnico y por género
El existencia o no de la discriminación en el mercado laboral ha sido un tema difícil de analizar. Comencemos por aclarar que para los propósitos de esta investigación, discriminación es un término que aplica a grupos claramente identificables por sus características físicas, religiosas, étnicas, por sus prácticas sociales, o por cualquier otro rasgo fácilmente observable1. En principio existe discriminación si las personas de dichos grupos reciben un tratamiento diferente basado solamente en su pertenencia al grupo en mención y dicho tratamiento diferente las coloca en una posición desventajosa. En el lenguaje comúnmente usado en la literatura sobre discriminación, el grupo discriminado generalmente se denomina minoría y el resto se denomina mayoría. Así por ejemplo, se habla de la población femenina o la población afrodescendiente como minorías, aunque en ocasiones pueden ser una población numéricamente más grande que la denominada mayoría.
Rumination: Practicing Retrieval of Autobiographical Memories
Background
People who ruminate about negative personal experiences seem to be engaged in practicing retrieval, with the expected consequences of perpetuating those very memories (see Roediger and Butler in Trends Cogn Sci 15:20–27, 2011). Method
To provide an experimental model of the effect of retrieval practice on subsequent recall of autobiographical memories, we recruited students with low and high scores on the Ruminative Response Scale (Treynor et al. in Cogn Ther Res 27:247–259, 2003), gave them positive and ruminative cues to generate memories, and cued three rounds of practice of half of the memories from each valence. Results
A week later, final cued recall for all memories showed strong practice effects, with the exception that ruminators benefited very little from the request to practice positive memories. Conclusion
Recalling personal memories benefits from prior practice in bringing them to mind. However, these results provide insufficient evidence to recommend training recall of positive autobiographical memories to counteract rumination
Diferencias en el desempleo por género. ¿ Hay discriminación en el acceso al trabajo?
Esta investigación analiza la iferencia existente entre las tasas de desempleo de hombres y mujeres en Colombia. Se observa que la tasa de desempleo de la mujer siempre ha sido superior a la del hombre y que en los últimos años la diferencia ha disminuido. Se busca establecer cuáles son las características de la mujer que hacen que su tasa de desempleo sea mayor a la del hombre. El proceso de esta investigación consiste en, primero, fijar las variables que afectan la probabilidad de desempleo, para luego estimar dichas probabilidades mediante modelos logit. Estas variables se pueden clasificar en dos grupos: el primero las que afectan el salario de reserva y el segundo las que afectan las ofertas salariales. De este modo, se hace un intento por encontrar que parte de la diferencia del desempleo entre hombres y mujeres se debe a los salarios de reserva y a las ofertas salariales. Es posible también determinar el impacto que tiene la diferencia de características promedio y de los coeficientes de las estimaciones sobre dicha diferencia. Para ello, se realizaron tres tipos de descomposiciones diferentes. Los resultados obtenidos apuntan a que la diferencia en coeficientes, que se puede tomar como el trato que se les da a las mujeres, explica en mayor parte la diferencia en las tasas de desempleo y que la diferencia en características lo hacen n menor medida. Por otro lado, se encontró que la diferencia en salarios de reserva afecta en forma positiva la diferencia entre las tasas de desempleo de hombres y mujeres, mientras que la de los salarios ofrecidos la reduce.
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