Reproducción de conejos bajo condiciones tropicales, efectos negativos y posibles soluciones / Reproduction of rabbits under tropical conditions, negative effects and possible solutions

RESUMEN La fisiología digestiva y capacidad reproductiva hacen del conejo una especie con potencial para la producción de carne. En clima templado, su adecuado manejo reproductivo permite obtener entre 6 y 10 partos anuales con camadas de 6 y hasta 12 gazapos. En zonas tropicales, el estrés calórico disminuye su capacidad reproductiva. Las hembras presentan un incremento en la secreción de corticosteroides, modificando la secreción de la hormona liberadora de gonadotropina (GnRH), la hormona estimulante del folículo (FSH) y la hormona luteinizante (LH), disminuyendo el crecimiento y desarrollo folicular, calidad de ovocitos y la ovulación, y con ello el número de partos y tamaño de camada. En los machos se afecta la libido y la capacidad de monta. En la calidad seminal, disminuye 7.8 % el volumen, 7.7 % la concentración, 1.7 % la morfología y 5.5 % la motilidad. El objetivo del presente trabajo fue describir las estrategias utilizadas para disminuir el estrés calórico, que incluyó regular la temperatura en las instalaciones, suplementos alimenticios, cruzamiento de razas locales con razas mejoradas, desarrollo de líneas genéticas para climas tropicales, implementación de biotecnologías reproductivas como la inseminación artificial o criopreservación de semen, mejorando el comportamiento reproductivo del conejo bajo condiciones tropicales.

ABSTRACT The digestive physiology and reproductive capacity of the rabbit make it a species with potential for meat production. In a temperate climate, its adequate reproductive management allows to obtain between 6 and 10 annual litters per female with 6 up to 12 kits per litter. In tropical areas, heat stress alters metabolism and hormonal function, decreasing their reproductive capacity. In females, the main changes include an increase in the secretion of corticosteroids, modifying the secretion of gonadotropinreleasing hormone (GnRH), stimulating follicle hormone (FSH) and luteinizing hormone (LH), decreasing the growth and follicular development, oocyte quality and ovulation, and with it the number of births and size of litter. In males, libido and ability to mate are affected. In the seminal quality, a decrease of 7.8 % in volume, 7.7 % in concentration, 1.7 % in morphology and 5.5 % in motility is observed. The objective of the present work was to describe the strategies used to reduce the caloric stress. These included regulating the temperature in the facilities, supplementary food, crossing of local breeds with improved breeds, development of genetic lines for tropical climates, implementation of reproductive biotechnologies such as artificial insemination or cryopreservation of semen, improving the reproductive behavior of the rabbit under tropical conditions.

Setting individualized positive end-expiratory pressure level with a positive end-expiratory pressure decrement trial after a recruitment maneuver improves oxygenation and lung mechanics during one-lung ventilation.

BACKGROUND: We investigated whether individualized positive end-expiratory pressure (PEEP) improves oxygenation, ventilation, and lung mechanics during one-lung ventilation compared with standardized PEEP. METHODS: Thirty patients undergoing thoracic surgery were randomly allocated to the study or control group. Both groups received an alveolar recruitment maneuver at the beginning and end of one-lung ventilation. After the alveolar recruitment maneuver, the control group had their lungs ventilated with a 5 cm·H2O PEEP, while the study group had their lungs ventilated with an individualized PEEP level determined by a PEEP decrement trial. Arterial blood samples, lung mechanics, and volumetric capnography were recorded at multiple timepoints throughout the procedure. RESULTS: The individualized PEEP values in study group were higher than the standardized PEEP values (10 ± 2 vs 5 cm·H2O; P < 0.001). In both groups, arterial oxygenation decreased when bilateral-lung ventilation was switched to one-lung ventilation and increased after the alveolar recruitment maneuver. During one-lung ventilation, oxygenation was maintained in the study group but decreased in the control group. After one-lung ventilation, arterial oxygenation was significantly higher in the study group (306 vs 231 mm·Hg, P = 0.007). Static compliance decreased in both groups when bilateral-lung ventilation was switched to one-lung ventilation. Static compliance increased significantly only in the study group (P < 0.001) after the alveolar recruitment maneuver and optimal PEEP adjustment. The alveolar recruitment maneuver did not decrease cardiac index in any patient. CONCLUSIONS: During one-lung ventilation, the improvements in oxygenation and lung mechanics after an alveolar recruitment maneuver were better preserved by ventilation by using individualized PEEP with a PEEP decrement trial than with a standardized 5 cm·H2O of PEEP.

Trace gases and particulate matter emissions from wildfires and agricultural burning in Northeastern Mexico during the 2000 fire season.

An inventory of air pollutants emitted from forest and agricultural fires in Northeastern Mexico for the period of January to August of 2000 is presented. The emissions estimates were calculated using an emissions factor methodology. The inventory accounts for the emission of carbon monoxide (CO), methane, nonmethane hydrocarbons, ammonia, nitrogen oxides, and particulate matter (PM). Particulate matter emissions include estimates for fine PM and coarse PM. A total of 2479 wildfires were identified in the domain for the period of interest, which represented approximately 810,000 acres burned and 621,130 short tons emitted (81% being CO). The main source of information used to locate and estimate the extent of the fires came from satellite imagery. A geographic information system was used to determine the type of vegetation burned by each fire. More than 54% of the total area burned during the period of study was land on the State of Tamaulipas. However, >58% of the estimated emissions came from the State of Coahuila. This was because of the mix of vegetation types burned in each state. With respect to the temporal distribution, 76.9% of the fires occurred during the months of April and May consuming almost 78% of the total area burned during the period of study. Analysis of wind forward trajectories of air masses passing through the burned areas and 850-mb wind reanalyses indicate possible transboundary transport of the emissions from Mexico to the United States during the occurrence of the major wildfires identified.

Programa educativo em medidas de precauçäo universais: uma metodologia de abordagem / Updating measures on universal precautions: a new approach methodology

No Centro de Atençäo Integral à Saúde da Mulher (CAISM) desenvolveu-se um programa de reciclagem sobre as Medidas de Precauçäo Universais (MPU) e divulgou-se, através de uma cartilha, essas medidas e os procedimentos em caso de acidente de trabalho. Primeiramente, o funcionário era sensibilizado para a questäo do estresse e sua influência sobre a qualidade de vida e, após, era realizada a reciclagem promovendo-se a reflexäo sobre as consequências da näo adoçäo das MPU. Foram respondidos e analisados 286 pré-testes e 242 pós-testes com um índice de acertos significativamente maior nestes últimos (p<0,01), principalmente quanto ao uso adequado de luvas.