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In Mexico, municipalities deposit their urban solid waste (USW) in uncontrolled sites or sanitary landfills (SL); therefore, there is a need to improve their conditions and know the existing impact on air, water and soil. The elemental characterization of the leachate, soil and water was carried out, a sample of well water near the SL (1.5 km) and leachate was characterized physicochemically and microbiologically. Air quality and weather conditions were analyzed. The leachate has a high organic load, nitrogenous matter and chlorides, and a low BOD5/COD biodegradability index of 0. The concentration of air pollutants is within the permissible limits because it is an open area and the wind speed favors their dispersion. In the soil there are concentrations of retained metals that prevent their migration to groundwater. [ABSTRACT FROM AUTHOR]

Introduction: The occurrence of lactation perturbations (LP) has negative impacts on milk production systems. Environmental effects have a direct relationship with the productive behavior of cows regarding LP. This can also be defined as the period between an initial decrease in milk production on a control day (DMPCD) and its subsequent recovery, because this decrease is understood as a fall in DMPCD that is not due to normal physiological processes Objective: To identify the probability of experiencing lactation perturbations according to farm effects, calving season, age at calving, and initial milk production level, using conditional probability analysis. Methods: Test day milk yield (TDMY) of 2725 first lactations of Lucerne cows were considered. The Wood model was used to estimate lactation curve parameters (a, b, and c). Conditional probability (CP) of experiencing at least one perturbation was calculated based on the factors: Farm (F1 and F2), calving season (CS, A, B, C, and D), age of the cow at calving (ACC), and initial milk production level (PL), these last two variables are categorized as low (less than 1 standard deviation), medium (between -1 and 1 standard deviation), and high (greater than 1 standard deviation) according to the distribution of each variable. Results and Discussion: The probabilities of experiencing disruptions for each level of each studied effect were: 0.87 and 0.93 (F1 and F2 respectively); 0.83 and 0.91, and between 0.86 and 0.94 for CS A to D in F1 and F2, respectively; between 0.79 and 0.94, and between 0.92 and 0.96 for ACC low to high in F1 and F2 respectively; between 0.84 to 0.87, and between 0.91 to 0.94 for PL low to high for F1 and F2, respectively. The PC by CS was higher in CS C (F1) and A (F2). Intermediate ACC and LP showed higher PC in both farms. Conclusion: Farm F2 exhibits a higher number of LP. The CP of LP according to CS, ACC, and LP changes according to the farm. [ABSTRACT FROM AUTHOR]

La ascosferosis o cría de cal, es una enfermedad infecciosa de las abejas melíferas (Apis mellifera) causada por el hongo Ascosphaera apis que ocasiona la muerte a sus larvas. En casos severos puede causar disminución de la población de abejas adultas y de productividad de la colonia. Este es el primer estudio que se realiza en México con la finalidad de determinar la prevalencia de A. apis en colonias de abejas melíferas en una región apícola. Se llevó a cabo en nueve municipios del sur de Jalisco, distribuidos en dos zonas climáticas (cálida subhúmeda y templada subhúmeda) y se analizó la relación del hongo con factores como altura sobre el nivel del mar, precipitación pluvial y temperatura ambiental. Se tomaron muestras de cría de abejas de 365 colonias, de las cuales, el 74.1 % fueron positivas a ascosferosis mediante análisis microscópico. El 75.6 % de las colonias de la zona cálida y el 72.2 % de la templada resultaron positivas a A. apis, respectivamente, y no fueron significativamente diferentes en la prevalencia de este hongo (P>0.05). El análisis de regresión logística indicó que al incrementarse la precipitación pluvial también se incrementa significativamente el número de colonias infectadas por A. apis (odds= 3.53; P

Este artículo tiene como propósito develar las percepciones que construyen los habitantes de los municipios de Arjona, Turbaco, El Carmen De Bolívar y Magangué, del departamento de Bolívar, sobre los efectos económicos, sociales y ambientales de la dinámica del oficio de mototaxismo, así como la efectividad de las acciones llevadas a cabo por las autoridades municipales y departamentales para su control. La estrategia metodológica empleada fue de corte cualitativo, a fin de visibilizar las voces de los actores locales que interactúan y se relacionan con el territorio en su cotidianidad. Para ello se desarrollaron entrevistas semi-estructuradas, dirigidas a usuarios y no usuarios del servicio de mototaxis y transportadores públicos y privados, así como grupos focales, conformados por funcionarios públicos de las alcaldías municipales. Los resultados muestran que, si bien el oficio de mototaxismo ha facilitado la movilidad tanto de las personas como de la mercancía de productores y comerciantes locales (formales e informales), ha generado conflictos sobre quién o quienes pueden transportar personas y mercancías, dada la legitimación de un oficio informal e ilegal que genera consecuencias al servicio de transporte legal. El oficio también ha traído consigo efectos ambientales, reflejados en la calidad del aire, conservación del suelo rural, el atractivo visual del municipio y la audición de la población. Respecto a las medidas de regulación de oficio del mototaxismo, se infiere un bajo conocimiento de ellas. Quienes indican conocerlas, consideran son poco efectivas, puesto que son transitorias y, en algunos casos, carecen de planificación.

An impact assessment should cover the following aspects: describe the proposed action, as well as other alternatives; predict the nature and magnitude of 'environmental effects'; predict human aspects; interpret the results and prevent environmental effects. In addition, a methodology must be available for the communication phases (information to the public and the executi ve) and, as the case may be, for inspection procedures during the construction and operation phase of the undertaking or action in question. [ABSTRACT FROM AUTHOR]

To characterize the reproductive performance of the Cuban Brown Creole rabbit breed, 7,488 mating, 5,876 born litters, 5,601 live litters and 3,567 weaned litters were used between 2014 and 2018. The traits fertility, total and live born, viability at birth and at weaning, number of weaned, litter weigh and individual at weaning were studied. Statistical analysis was performed with the SAS statistical package. The statistic general mean, coefficient of variation and standard deviation were determined. The influence of the trimester (4 classes) and the year (5 levels) was analyzed with a mixed generalized linear model, whose random effect was the breeder in each mating/kindling. Pearson correlations were also calculated between the studied traits. It was shown that the reproductive performance of this breed was affected by the trimester (P <0.05) and the year (P <0.0001). The 75 % of the characters showed better performance, when the mating and kindling occurred in the first trimester with respect to the third. The effect of the year showed the influence on the conditions of each year, with maximum expression in 2014. The trait live born was the most stable in time, an advantageous performance for the prolificacy of this breed. High correlations (+0.80) were found between total and live born, and between the weaned number and the litter weight. The reproductive performance of this breed is conditioned by environmental factors, so by improving its management, its productivity can be increased and a sustainable use of this zoogenetic resource can be made. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Latin American & Caribbean Studies (Taylor & Francis Ltd) is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Paideia (0103863X) is the property of Paideia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La contribución de la extracción de gas lutita en la sostenibilidad energética ha sido evalua-da de manera independiente, sin tener en cuenta su relación con la seguridad hídrica ni sus impactos en las fuentes de agua. Por esta razón, en la presente investigación se realizó un análisis de estos impactos a través de una revisión bibliográfica de carácter nacional e inter-nacional. Si bien el análisis hecho sugiere dos aspectos fundamentalmente importantes: 1) impactos en el recurso hídrico asociados a la cantidad y calidad de este y 2) efectos sísmi-cos o sismicidad inducida, este estudio se enfoca principalmente en el primero. Los resul-tados de la revisión demuestran un creciente aumento de investigaciones sobre el impacto del fracking; sin embargo, se encontró que hay deficiencias en el uso de modelos numéricos para cuantificar los efectos ambientales. Adicionalmente, los resultados muestran que los consumos asociados a la estimulación hidráulica no parecen ser significativos compara-dos con los usos típicos en otras prácticas económicas, como la agricultura (riegos). En este sentido, en el contexto colombiano los retos se basan en consolidar una mejor red de información piezométrica y en general un sistema de monitoreo más robusto para mejorar la toma de decisiones respecto al fracking, ya que este tipo de información representa el primer paso hacia la construcción de modelos hidrogeológicos que soporten la evaluación del riesgo y contribuyan a la reducción de la posible vulnerabilidad del recurso hídrico en el desarrollo de proyectos de aprovechamiento de gas lutita.

Copyright of Lámpsakos is the property of Fundacion Universitaria Luis Amigo, Facultad de Ingenierias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bistua: Revista de la Facultad de Ciencias Básicas is the property of Facultad de Ciencias Basicas de la Universidad de Pamplona and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agriscientia is the property of Revista AgriScientia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Panorama Económico is the property of Universidad de Cartagena and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At a global level, the need to produce food for a growing population, demanded the search of suitable lands for that purpose. In this way, agricultural production generated the displacement of other land uses, which caused numerous environmental problems. Among them, the impact on the services provided by ecosystems is highlighted and its implications are not observed with the same intensity in all landscapes. The "Región Pampeana Austral (RPA)" [Southern Pampean Area], in the denominated "Región Pampeana Argentina" [Argentine Pampean Area], was not external to what happened. Thus, the work aims to analyze the land use changes in the county of Necochea, a representative área of the RPA, for the 2002-2017 period, through remote sensing. Besides, it is proposed to identify potential implications of these transformations on landscapes and its incidence on ecosystem services (ES). The results shown an increment of the agricultural área in 37,82% and a decline of livestock in a 53,75%. This situation is expressed with more emphasis in the landscapes of "Llanura ondulada" [Wavy plains] and "Llanura periserrana" [Mountains surrounding plains]. Likewise, it is observed that the provisioning and regulating services would be the most affected, and it is in the mentioned landscapes where the gratest implications would be evident. Finally, it is vital to incorporate the analysis of cultural ES and thus achieve a more complete contribution in order to set environmental management guidelines. [ABSTRACT FROM AUTHOR]

The records of Mambí de Cuba dairy cows (3/4 Holstein 1/4 Cebu), Siboney de Cuba (5/8 Holstein 3/8 Cebu) and Holstein, from three herds were used to determine the effect of the genetic group (GG) and various non-genetic factors, for milk production traits (131 658 lactations of 63 066 cows), reproduction (117 794 reproductive events of 36 331 cows), longevity (18 741 cows) and milk production per life (56 536 cows). The traits of cumulative milk production up to 305 days (M305), duration of lactation (DL), age at first service (A first service), parturition-first service interval (PSI), parturition-gestation interval (PGI), parturition interval (PI),productive life (PL), number of parturition per life (PN) and milk production per life (MPLife) were studied. A mixed linear model was applied, with the use of the SAS MIXED procedure. This model included the fixed effects of the genetics, herd, lactation number, year, parturition time, genetic group interactions x lactation number, genetic group x parturition year and genetic group x parturition time. As random, the cow nested in the herd and the errors were included. For the A first S, PL, PN and MPLife traits, the model did not include the lactation number or its interaction. The fixed effects were significant, except for the parturition time and its interaction with the genetic group in the reproductive and longevity traits. It is concluded that the Mambí de Cuba showed better milk production accumulated during life and high longevity. [ABSTRACT FROM AUTHOR]

Evolutionary theory suggests that natural selection should favor the ability of animals to modify their offspring sex ratios when the fitness benefits of producing one sex over the other vary in relation to environmental conditions. The Saltmarsh Sparrow (Ammodramus caudacutus) is an extreme habitat specialist, with breeding behavior influenced by the tidal cycle. The challenges of nesting in the harsh environment of salt marshes and the unique promiscuous mating system of the Saltmarsh Sparrow provide a context for offspring sex ratio manipulation. We investigated adaptive sex ratio manipulation in this system across multiple sites and years using a mixed modeling approach. We collected data on nest initiation and nestling survival from 370 nests of 210 females during 2011-2015 in 4 marshes in the northeastern United States. Using molecular techniques, we determined the sex of 990 offspring and characterized variation in site- and population-level sex ratios. Using binomial linear mixed-effects models, we tested the influence of environmental, temporal, and maternal factors on offspring sex ratios. Across years and sites, we found an even offspring sex ratio of 1.03:1, with an alternating pattern of interannual variation between male and female bias at both the population and site level. The fluctuating sex ratio mirrored that of the adult sex ratio in the preceding year. Sex ratios did not vary as a function of timing of breeding within the breeding season or in relation to tidal flooding. Offspring sex was also independent of female condition at the time of nest initiation. Taken together, our findings suggest that female Saltmarsh Sparrows do not manipulate the sex ratio of their clutches in relation to environmental, temporal, or maternal factors. Our finding of a 1:1 offspring sex ratio and interannual variation in offspring and adult sex ratios in a wild bird population is more consistent with the predictions of Fisher (1930) than with those of Trivers and Willard (1973). [ABSTRACT FROM AUTHOR]

La contribución de la extracción de gas lutita en la sostenibilidad energética ha sido evaluada de manera independiente, sin tener en cuenta su relación con la seguridad hídrica ni sus impactos en las fuentes de agua. Por esta razón, en la presente investigación se realizó un análisis de estos impactos a través de una revisión bibliográfica de carácter nacional e internacional. Si bien el análisis hecho sugiere dos aspectos fundamentalmente importantes: 1) impactos en el recurso hídrico asociados a la cantidad y calidad de este y 2) efectos sísmicos o sismicidad inducida, este estudio se enfoca principalmente en el primero. Los resultados de la revisión demuestran un creciente aumento de investigaciones sobre el impacto del fracking; sin embargo, se encontró que hay deficiencias en el uso de modelos numéricos para cuantificar los efectos ambientales. Adicionalmente, los resultados muestran que los consumos asociados a la estimulación hidráulica no parecen ser significativos comparados con los usos típicos en otras prácticas económicas, como la agricultura (riegos). En este sentido, en el contexto colombiano los retos se basan en consolidar una mejor red de información piezométrica y en general un sistema de monitoreo más robusto para mejorar la toma de decisiones respecto al fracking, ya que este tipo de información representa el primer paso hacia la construcción de modelos hidrogeológicos que soporten la evaluación del riesgo y contribuyan a la reducción de la posible vulnerabilidad del recurso hídrico en el desarrollo de proyectos de aprovechamiento de gas lutita.

This study estimates the regional environmental consequences of the impactor extraterrestrial body that could produce the probable Vichada impact crater structure on the Vichada Plain, in Colombia, South America. This paper details the parameter assumptions upon which the estimation is made. It describes an approach to quantifying the principal impact processes that could have affected the landscape in the vicinity of the probable Vichada impact event in the past. The key parameters are impactor diameter, impactor density, impact velocity before atmospheric entry, impact angle, and the distance from the impact at which the environmental effects are to be calculated, and the target type of sedimentary rock or crystalline rock. These parameters were chosen with support from The Vichada Structure dimensions obtained from remote sensing data interpretation, regional geologic mapping and interpreted satellite data and ground-based gravity and magnetic anomalies. The calculations are based on compiled novel algorithms for estimating the thermal radiation emitted by the impact-generated vapor plume or fireball, and the intensity of seismic shaking. Model validation is performed by obtaining the approximates various dimensions of the Vichada impact crater and ejecta deposit, as well as estimating the severity of the air blastin both crater-forming and air burst impacts. We illustrate the utility of the calculations by examining the predicted environmental consequences in seven localities of the Colombian territory, through hypothetical impact scenarios occurring in Cumaribo and Puerto Carreño (Vichada), Puerto Inirida (Guainía), Puerto Gaitán and Villavicencio (Meta), Mitú (Vaupes) and Bogotá, D.C. It is concluded that the most wide-reaching environmental consequence is seismic shaking. Both ejecta deposit thickness and air-blast pressure decay much more rapidly with distance than with seismic ground motion. Close to the impact site the most devastating effect is from thermal radiation; however, the curvature of the Earth implies that distant localities are shielded from direct thermal radiation because the fireball is below the horizon. These results would guide further detailed fieldwork hunting for direct impact crater evidences and/or interpreting high resolution geophysical studies and borehole that could be carried out in the probable Vichada impact crater area in the near future. [ABSTRACT FROM AUTHOR]

Copyright of Ciencia e Ingenieria Neogranadina is the property of Ciencia e Ingenieria Neogranadina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Este artículo tiene como objetivo analizar y determinar la asignación óptima de los recursos financieros a la zona minera "El Faique" con el fin de obtener una producción eficiente, sin causar efectos negativos al ambiente; la degradación ambiental ha cobrado gran importancia a nivel mundial en vista que los procesos de producción de cualquier tipo ocasionaran una afectación, en algunos casos irreversibles, que traerá como consecuencia una alteración en el presupuesto económico del proyecto, de allí, la importancia de investigar la planificación y posterior implemento en el presupuesto de un proyecto cuyo objetivo será minimizar todas estas interacciones negativas del proyecto. Contribuyendo con ello al desarrollo sustentable de los procesos productivos mineros. El estudio se realizó en el proyecto El Faique, evaluando los siguientes indicadores: campo minero, proceso de exploración, (franqueo de galerías), y la interacción con el área de influencia social del pro- yecto. Se utilizaron métodos descriptivos que determinen la forma de cómo se encuentra el sector, y luego a través de métodos automatizados proceder a describir las afectaciones. Los resultados determinan que no existe intercambio posible de bienes que permita aumentar el bienestar de alguien sin empeorar el bienestar de otra persona, sin embargo, que los componentes sociales son muy importantes al momento de realizar el presupuesto.

La mastitis es la enfermedad que mayores pérdidas económicas ocasiona a las ganaderías de leche en el mundo, y el recuento de células somáticas (RCS) es una manera indirecta de medir la incidencia de esta infección. El intervalo entre ordeños es un factor que afecta el RCS, dificultando la precisión en la estimación de este, en programas de control de producción lechera y mejoramiento animal en los que solo se hagan mediciones en uno de los dos ordeños. El objetivo fue diseñar un modelo de predicción para el RCS total día, a partir de muestreos parciales en un solo ordeño, para ser utilizados posteriormente en programas de estimación de valores genéticos para la característica. La investigación fue realizada en tres hatos con 182 vacas Holstein, la información fue analizada mediante un modelo de regresión múltiple donde se encontró que los parámetros con mayor incidencia sobre el RCS fueron: número de parto, intervalo entre ordeños y días en lactancia. Posteriormente, a partir de los efectos significativos se ajustó un modelo de regresión múltiple definitivo que permite predecir el recuento de células somáticas día, a partir de muestreos parciales. Los coeficientes de regresión calculados para el intervalo entre ordeños y los días de lactancia con respecto al recuento de células somáticas fueron 13,4619 y 0,259182 respectivamente. Este modelo tuvo un coeficiente de determinación r2 de 0,953 convirtiéndose en un buen predictor de este parámetro.Abstract. Mastitis is the disease that causes the greatest economic losses in dairy herds in the world. Somatic cells count (SCC) is an indirect way of measuring the incidence of this infection. Milking interval is a factor that affects the SCC, preventingits accurate estimation in milk production control programs and animal improvement programs in which measurements are taken only in one of the two milkings. This research was aimed to obtain a prediction model for daily total SCC, based on information from a single milking, to be used on programs for estimating the RCS genetic values. The research was conducted on three herds with 182 dairy cows. Information was evaluated by multiple regression techniques, finding that the parameters that influenced SCC the most, were parity, milking interval and days in milk. A final multiple regression model was fitted using only the significant effects, which predicts the daily total SCC from partial sampling. Regression coefficients for the intervals between milking and days of lactation were 13.4619 and 0.259182, respectively. The model had a coefficient of determination of 0.953, becoming a good prediction model for daily total SCC.

Título en inglés: Environmental effects of agrochemicals and agricultural machinery in transgenic and conventional crops cotton Resumen La producción de alimentos se basa en el uso de diferentes tecnologías agrícolas, que pueden derivar en conflictos entre medioambiente y agricultura. Es significativo estudiar el impacto ambiental de las nuevas tecnologías aplicadas a la agricultura, la más importante de las cuales es la transgénesis. Este trabajo se realizó en la zona algodonera del municipio del Espinal, departamento del Tolima, para la cosecha de algodón del primer semestre de 2009, usando las metodologías de Brookes y Barfoot (2006) y Kovach y colaboradores (1992). Se estudió el efecto ambiental de la aplicación de agroquímicos y el uso de maquinaria agrícola en cultivos de algodón transgénico y convencional. Se recogió información mediante encuestas en veinte fincas productoras de algodón. El análisis de las encuestas se realizó de forma descriptiva, determinando diferencias de tipo cuantitativo y cualitativo para los predios que utilizan la tecnología convencional o la tecnología transgénicas (doble gen, Bt/RR), para luego realizar una correlación con el “Enviromental Index Quotient” (EIQ). No se encontraron diferencias entre el EIQ de campo de las dos tecnologías, aunque la tecnología transgénica tiene ventajas ambientales en el control de algunas plagas de lepidópteros. En relación con el uso de maquinaria agrícola, se encontró que la tecnología convencional genera menor liberación de CO2, gas de efecto invernadero. La metodología de Brookes y Barfoot puede adaptarse para estudios comparativos de tecnologías agrícolas en países tropicales. Palabras clave: algodón; cultivos transgénicos; efectos ambientales; maquinaria agrícola; emisiones CO2; EIQ. Abstract Food production is based on the use of various agricultural technologies, which can lead to conflicts between environment and agriculture. It is important to study the environmental impact of new technologies applied to agriculture, the most important of which is transgenesis. This work was carried out in the cotton belt of the town of Espinal, Tolima Department for the cotton crop in the first half of 2009, through methodologies Brookes & Barfoot (2006) and Kovach et al (1992). We studied the environmental impact of pesticide application and use of agricultural machinery for cultivation of transgenic and conventional cotton. Information was collected through surveys of 20 farms producing cotton. The analysis of the survey was conducted descriptively, by determining differences in quantitative and qualitative for the sites that use conventional technology, and transgenic (Bt gene and double RR / RR), and then make a correlation with the Environmental Index Quotient (EIQ). No differences were found between the fields EIQ the two technologies, although transgenic technology has environmental advantages in the control of some lepidopteran pests. In connection with the use of agricultural machinery, was found to conventional technology generates less release of CO2, greenhouse gas. The Brookes and Barfoot methodology could be adapted in comparative studies of agricultural technologies in tropical countries. Key words: Cotton; transgenic crops; environmental effects; agricultural machinery; CO2 emissions; EIQ.

Las tecnologías de la información y las comunicaciones (TIC), tienen un profundo impacto en la economía y en el ambiente. La mejora en el desempeño de las tic lleva a un amento creciente del consumo de productos y servicios relacionados con TIC, lo cual tiene numerosas implicaciones ambientales en diferentes niveles. En este artículo, los autores resaltan la analogía entre los efectos rebote en el sector de energía y los efectos del crecimiento en TIC. De la literatura de economía energética se toman diferentes taxonomías de los efectos rebote con el fin de estructurar la discusión sobre las implicaciones ambientales del crecimiento en el uso de productos y aplicaciones de las TIC. El autor distingue dos niveles de impactos ambientales de las TIC. El primero, tiene que ver con ciclo de vida del hardware de las TIC y el segundo con la forma como se usan las aplicaciones de las TIC. Por medio de ejemplos, el artículo ilustra la complejidad de los impactos ambientales y resalta el rol decisivo del comportamiento humano en determinar su significancia. Los temas presentados son de gran relevancia para cualquier tomador de decisiones que ha puesto grandes expectativas en las TIC, y que necesita ser advertido sobre sus potenciales implicaciones ambientales en los complejos sistemas socioeconómicos de hoy. Se suelen hacer inversiones cuantiosas en este sector con la expectativa de crecimiento económico y mejoramiento ambiental, pero se ignora que el efecto rebote causa el riesgo de mala asignación de recursos. Disponer de mayor información sobre los efectos y causas de estos, permitirá a los tomadores de decisiones optimizar el desarrollo con un balance entre el crecimiento y la calidad ambiental.

In order to evaluate genetic and environmental factors that influence on milk production and reproduction in cows with different proportions of Bos taurus x Bos indicus genes, an amount of 19,643 lactations of Mambí de Cuba (3/4 Holstein ¼ Zebu) cows and 15,925 lactations of Siboney de Cuba (5/8 Holstein 3/8 Zebu) cows were used, which belonged to three cattle farms, during the parturition years, from 1987 to 2012. The studied traits were accumulated milk production up to 305 d (L305), lactation duration (LD), milk production per day (MPD), period between parturition and gestation (PPG), period between parturitions (PP) and milk production per day during the period between parturitions (MPPP). A linear mix model was applied with the use of MIXED procedure of SAS. Fixed effects included genetic groups, herd, lactation number, year, parturition season, interactions of genetic group x lactation number, genetic group x parturition year and genetic group x parturition season. The cow nested in the herd and the error were considered as random effects. Mambí de Cuba and Siboney de Cuba cows showed similar reproductive performance and lactation duration. However, milk productions were superior in Mambí de Cuba cows in 84.43 kg, 0.29 kg/d and 0.69 kg/d, for L305, MPD and MPPP, respectively. It can be concluded that there was better milk performance in Mambí de Cuba and similar averages for reproductive periods and lactation duration. [ABSTRACT FROM AUTHOR]

This article proposes the use of a hybrid methodology for solving CVRP (Capacitated Vehicle Routing Problem) considering environmental effects. The problem is solved under route-first, cluster-second. The routing step is solved exactly using an integer linear model. The assigning step is performed by applying a modified genetic algorithm that considers the sequence found in the above step as a starting point to generate the initial population. Optimize the objective function corresponds to the minimization of weight-distance travel along the route, as an indicator of environmental impact. The methodology is validated with test cases from the literature. [ABSTRACT FROM AUTHOR]