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1.
J Plant Res ; 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39014142

RESUMEN

Plant biomass allocation is mainly affected by the environment where each individual grows. In this sense, through the rapid global expansion of impermeable areas, urbanization has strong, albeit poorly understood, consequences on the biomass allocation of plants found in this environment. Nevertheless, the comprehension of biomass allocation processes in urban shrubs remains unclear, because most studies of urban ecology focus on tree species. This is an important gap of knowledge because a great part of urban vegetation is composed of shrubs and their association with trees have positive impacts in urban ecosystem services. In this study, we explored the ecological and potential selective pressure effects of an urbanization gradient on the biomass allocation patterns of aboveground organs of Turnera subulata, a widely distributed tropical shrub. We have demonstrated that, for certain reproductive organs, biomass allocation decreases in locations with higher urbanization. Unlike expected, the biomass of vegetative organs was not affected by urbanization, and we did not observe any effect of urbanization intensity on the variance in biomass allocation to vegetative and reproductive organs. We did not record urbanization-mediated trade-offs in biomass allocation for reproductive and vegetative organs. Instead, the biomass of these structures showed a positive relationship. Our data suggest that urbanization does not result in radical changes in biomass allocation of T. subulata, and neither in the variation of these traits. They indicate that the ability of T. subulata to thrive in urban environments may be associated with life history and morphological mechanisms. Our findings contribute to the understanding of shrub plant responses to urbanization and highlight urbanization as a potential factor in resource allocation differences for different structures and functions in plants living in these environments.

2.
Arq. bras. med. vet. zootec. (Online) ; 73(3): 622-630, May-June 2021. tab
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1278347

RESUMEN

This study aimed to determine the physiological and hematological parameters of sheep in Brazil. Therefore, 5,081 observations were used from previous experiments with animals from different Brazilian regions with the time of day, gender, breed, age, physiological characteristics, hematological and climatic variables. The animals were classified according to their stress level, and only data of non-stressed animals were used to calculate the reference values. Respiratory rate was the parameter that most differed from the normal range, with values ​​above the limits usually reported for the species, being higher in commercial wool sheep. For hematological variables, differences were observed between the present results and the previously reported values in the literature. A higher number of red blood cells (RBC), lower hemoglobin and mean corpuscular hemoglobin concentration (MCHC) were observed in young animals. A higher number of RBC and MCHC were noted in sheep crossed with local breeds. Considering that physiological and hematological parameters are indicators of the animal's pathological or physiological state, for a correct interpretation of the results, the use of reference values based on animals with similar racial characteristics and subjected to similar environmental conditions is recommended.(AU)


O objetivo deste estudo foi determinar parâmetros fisiológicos e hematológicos de ovinos no Brasil. Portanto, foram utilizadas 5.081 observações de experimentos anteriores com animais de diversas regiões do Brasil, com diferentes horário, sexo, raça, idade, características fisiológicas, variáveis ​​hematológicas e climáticas. Os animais foram classificados de acordo com o nível de estresse, e apenas os dados dos animais não estressados ​​foram utilizados para o cálculo dos valores de referência. A frequência respiratória foi o parâmetro que mais diferiu em relação à normalidade, com valores acima dos limites usualmente relatados para a espécie, sendo maior em ovinos de lã comercial. Para as variáveis ​​hematológicas, também foram verificadas diferenças entre os resultados observados e os valores previamente relatados na literatura. Maior número de hemácias, menor hemoglobina e concentração de hemoglobina corpuscular média (CHbCM) foram observados em animais jovens e maior número de hemácias e CHbCM em ovinos cruzados com raças locais. Considerando que os parâmetros fisiológicos e hematológicos são indicadores do estado patológico ou fisiológico do animal, para uma correta interpretação dos resultados recomenda-se a utilização de valores de referência baseados em animais com características raciais semelhantes e submetidos a condições ambientais também semelhantes.(AU)


Asunto(s)
Animales , Ovinos/fisiología , Ovinos/sangre , Valores de Referencia , Clima Tropical , Temperatura Corporal , Brasil , Frecuencia Respiratoria , Pruebas Hematológicas/veterinaria
3.
Arq. bras. med. vet. zootec. (Online) ; 73(1): 123-131, Jan.-Feb. 2021. tab
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1153058

RESUMEN

The aim of this study was to evaluate the reproductive performance of sows in individual stalls (Stall) or group-housed into groups on days 3 to 5 (Pen5) or 38 to 42 (Pen42) after breeding. The reproductive data was collected from the operating system of the farm establishing the average of the weekly performances of the sows that gave birth, for four years, except for the Pen5 system, which was evaluated for three years. Statistical analyses were performed using SAS®, using MIXED (for quantitative traits), NPAR1WAY (for categorical traits) and LOGISTIC (binomial traits) procedures, using sows as a repeated measure. Sows in Stall system had piglets with higher birth weight them sows in the group-housed system (P<0.05), however the piglets born alive, total piglets weaned, average litter weight, and duration of farrowing were lower in this system than in the group-housed (P<0.0001). There was no difference between Pen5 and Stall systems for gestation period and mummified piglets. The Pen42 system had a higher percentage of mummified piglets and a shorter gestation period, when compared Pen5 and Stall systems (P<0.0001), and similar results to the Pen5 system for duration of farrowing, piglets born alive, stillbirths, total piglets weaned, average litter weight and birth weight (P<0.0001).(AU)


O objetivo deste estudo foi avaliar a performance reprodutiva de matrizes suínas alojadas individualmente (Individual) ou em grupos, nos dias 3 a 5 (Grupo 5) ou 38 a 42 (Grupo 42) após a inseminação. Os dados reprodutivos foram coletados do sistema operacional da granja, estabelecendo-se a média dos desempenhos semanais das matrizes que pariram por semana, durante quatro anos, exceto para o sistema Grupo 5, que foi avaliado por três anos. A análise estatística foi realizada com SAS®, usando-se os procedimentos MIXED (para variáveis quantitativas), NPAR1WAY (para variáveis categóricas) e LOGISTIC (para variáveis binomiais), tendo a matriz como uma medida repetida. As matrizes no sistema Individual tiveram leitões com maior média de peso ao nascer do que as matrizes nos sistemas de alojamento em grupo (P<0,05), porém os leitões nascidos vivos, o total de leitões nascidos, o peso médio da leitegada e a duração do parto foram menores no sistema Individual do que nos sistemas de alojamento em grupo (P<0,0001). Não houve diferença entre os sistemas Grupo 5 e Individual para o tempo de duração da gestação e o número de leitões mumificados. O sistema Grupo 42 apresentou maior porcentagem de leitões mumificados e menor período de gestação, quando comparado aos sistemas Grupo 5 e Individual (P<0,0001), e resultados semelhantes ao sistema Grupo 5 para duração do parto, leitões nascidos vivos, natimortos, total de leitões desmamados, peso médio da leitegada e peso ao nascer (P<0,0001).(AU)


Asunto(s)
Animales , Femenino , Reproducción , Porcinos/fisiología , Bienestar del Animal , Tasa de Natalidad , Parto
4.
Rev Sci Instrum ; 91(5): 053301, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32486736

RESUMEN

This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.

5.
Trop Anim Health Prod ; 49(5): 975-982, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28429190

RESUMEN

The ability to predict the effects of climatic factors on animals and their adaptability is important for livestock production. The aim of the present study was to analyze whether existing indices are suitable for evaluating heat stress in Santa Ines and Morada Nova sheep, which are locally adapted hair sheep breeds from northeastern Brazil, and if the limits used to classify thermal stress are suitable for these breeds. Therefore, climatic, physiological, and physical parameters, as well as thermographic images, were collected in 26 sheep, 1 1/2 years old, from two genetic groups (Santa Ines 12 males and 4 females; Morada Nov. 7 males and 3 females) for 3 days in both morning (4:00 a.m.) and afternoon (2:00 p.m.) with six repetitions, totalizing 156 repetitions. Statistical analysis included correlations and broken-line regressions. Iberia and Benezra indices were the tolerance tests that best correlated with the assessed parameters. High correlations between environmental indices and rectal or skin surface temperatures was observed, which indicates that these indices can be used for Santa Ines and Morada Nova sheep raised in central Brazil. However, some indicative values of thermal discomfort are different from the existing classification. Therefore, in order to classify appropriately, the model used needs to be carefully studied, because these classifying values can vary according to the species and model. Further research is necessary to establish indicators of thermal stress for sheep breeds raised in the region.


Asunto(s)
Crianza de Animales Domésticos/métodos , Ambiente , Oveja Doméstica/fisiología , Termotolerancia , Animales , Brasil , Femenino , Masculino , Oveja Doméstica/genética , Especificidad de la Especie
6.
Phys Rev Lett ; 116(20): 206803, 2016 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-27258881

RESUMEN

The relation between unusual Mexican-hat band dispersion, ferromagnetism, and ferroelasticity is investigated using a combination of analytical, first-principles, and phenomenological methods. The class of material with Mexican-hat band edge is studied using the α-SnO monolayer as a prototype. Such a band edge causes a van Hove singularity diverging with 1/sqrt[E], and a charge doping in these bands can lead to time-reversal symmetry breaking. Herein, we show that a material with Mexican-hat band dispersion, α-SnO, can be ferroelastic or paraelastic depending on the number of layers. Also, an unexpected multiferroic phase is obtained in a range of hole density for which the material presents ferromagnetism and ferroelasticity simultaneously.

7.
Nat Commun ; 6: 7630, 2015 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-26138034

RESUMEN

Topological insulators are a new class of matter characterized by the unique electronic properties of an insulating bulk and metallic boundaries arising from non-trivial bulk band topology. While the surfaces of topological insulators have been well studied, the interface between topological insulators and semiconductors may not only be more technologically relevant, but the interaction with non-topological states may fundamentally alter the physics. Here, we present a general model to show that this type of interaction can lead to vertical twinning of the Dirac cone, whereby the hybridized non-spin-degenerate interfacial states cross twice as they span the bulk bandgap. This hybridization leads to spin-momentum locking of non-topological states with either helical (clockwise or anticlockwise) or even anti-helical (negative winding number) spin orientation depending on the parametization of the interaction. Model results are corroborated by first-principles calculations of the technologically relevant Bi2Se3 film van der Waals bound to a Se-treated GaAs substrate.

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