522 research outputs found
Water intake in sheeps fed different levles of prickly pear (Opuntia Ficus Indica) in Brazil
En 45 ovinos machos Santa Inés (peso vivo
medio de 27,50 ± 0, 48 kg) se evaluó el consumo
de agua, al consumir raciones con niveles crecientes
(0, 25, 50, 75, 100%) de nopal (Opuntia
fícus indica Mill) en sustitución al maíz molido. El
diseño fue en bloques al azar con nueve repeticiones.
El consumo de materia seca respondió de
modo cuadrático, perjudicando el peso final, que
disminuyó, con el aumento del nopal en la dieta.
Aumentó el consumo de materia natural disminuyendo
el de agua, el consumo total de agua
aumentó en el tratamiento con mayor cantidad de
nopal. La relación de consumos: agua voluntaria/
materia seca, disminuyó al aumentar el nopal. El
nopal constituye una reserva de agua para ovinos
Santa Inés en condiciones semiáridas de Brasil.The water intake in 45 male (27.50 ± 0.48 kg
of mena body weight) Santa Ines sheep fed with
increasing levels (0, 25, 50, 75, 100% DM basis)
of prickly pear (Opuntia ficus indica Mill) to replace
corn was studied. A completely randomized block
design with nine replications per treatment was
used. Quadratic behavior was observed for the
intake of dry matter, hitting the final weight, which
decreased with increasing the cactus in the diet.
There was an increase in the intake of natural
material and a decrease in voluntary water intake;
total water intake increased, and the ratio of
intakes: water/dry matter, decreased in the
treatment with larger cactus proportion. The pryckly
pear constitues a water reservoir for Santa Inês
sheep in Brazilian semiarid conditions
Histology of the skin of the blanca serrana goat bred in different production systems
Este trabajo tuvo como objetivo caracterizar la piel de caprinos de raza Blanca Serrana Andaluza, criados en sistemas de producción intensivo y extensivo. Fueron sacrificados 31 animales de la raza Blanca Serrana Andaluza (16 en extensivo y 15 en intensivo) con 20 kg de peso vivo. Se encontraron diferencias significativas (p0,05) entre los dos sistemas de producción analizados. Las características de la piel de los chivos revelaron pieles de primera calida
Ultraviolet Fixed Points in Gauge and SUSY Field Theories in Extra Dimensions
We consider gauge field theories in following the Wilson RG approach
and show that they possess the ultraviolet fixed points where the gauge
coupling is dimensionless in any space-time dimension. At the fixed point the
anomalous dimensions of the field and vertex operators are known exactly. These
fixed points are nonperturbative and correspond to conformal invariant
theories. The same phenomenon also happens in supersymmetric theories with the
Yukawa type interactions.Comment: LaTeX, 10pp. v2: Comments and references adde
Resonance expansions in quantum mechanics
The goal of this contribution is to discuss various resonance expansions that
have been proposed in the literature.Comment: 10 pages and 1 figure; presented at the Istanbul workshop on
pseudo-Hermitian Hamiltonian
Diverse young stellar populations in the intermediate-redshift radio galaxies 3C 213.1 and 3C 459: implications for the evolution of the host galaxies
We present European Southern Observatory Very Large Telescope (ESO VLT) and William Herschel Telescope (WHT) spectroscopic observations of two powerful radio galaxies at intermediate redshifts (3C 213.1 and 3C 459), obtained with the aim of establishing the nature and evolutionary status of the host galaxies. Spectral synthesis modelling has been used to demonstrate that young stellar populations (YSP) make a major contribution to the integrated optical light in both sources, contributing at least 37 and 80 per cent of the integrated B-band light in 3C 213.1 and 3C 459, respectively. While in the case of 3C 213.1 the YSP has an intermediate age (0.4–0.8 Gyr) and comprises 3–30 per cent of the total stellar mass, adequate fits to the spectra of 3C 459 require a combination of younger (<0.1 Gyr) and intermediate (0.2–1.2 Gyr) age YSP components that together comprise 5–100 per cent of the total stellar mass. Both the optical and far-IR properties of 3C 459 are consistent with its status as an ultraluminous infrared galaxy (ULIRG), and a scenario in which the observed radio source has been triggered close to the peak of star formation activity in a major gas-rich merger. On the other hand, in 3C 213.1 it is likely that the radio source has been triggered (or re-triggered) a significant period after the starburst peak, and the far-IR luminosity of the source is substantially lower. Following correction for the contributions of the YSP, the absolute magnitudes of the host galaxies of both sources are relatively modest (≤2L*), thus demonstrating that powerful radio activity is not always associated with the most massive and luminous elliptical galaxies. These results serve to emphasize that the radio source population is diverse, in terms of both the host galaxy properties and the triggering mechanism(s) for the radio source activity
Psychometric characteristics of a commuting-to-school behaviour questionnaire for families
The purposes of this study were: (a) to describe the patterns of modes of commuting to school (children) and to work (parents) separated by gender and age, (b) to validate the questions on children’s mode of commuting to and from school according to their parents, and (c) to analyse the reliability of a family questionnaire focused on commuting to school behaviours. A total of 611 parents (mean age: 43.28 ± 6.25 years old) from Granada (Spain) completed “Family commuting-to-school behaviour” questionnaire in two sessions separated by 14 days, (2016 and 2018). The validation between family and children’s questions was assessed using the Kappa and Spearman correlation coefficients, and the test–retest reliability within the family questions was assessed using the Kappa and the weighted Kappa. The children’s modes of commuting to school (mean age: 11.44 ± 2.77 years old) were mainly passive (57.7% to school) while parents’ modes of commuting to work were mainly active (71.6%). The validity of the mode of commuting was significant with high Kappa and Spearman coefficients. The test–retest reliability presented a good agreement for the mode of commuting to school in children, distance and time to school, and the mode of commuting to work in parents, while the questions on acceptable distance to walk or cycle to school showed a moderate to good agreement. The “Family commuting-to-school behaviour” questionnaire could be a useful tool to assess the mode of commuting of children, distance and time to school for researchers and practitioners
Probing quantum gravity using photons from a flare of the active galactic nucleus Markarian 501 observed by the MAGIC telescope
We analyze the timing of photons observed by the MAGIC telescope during a
flare of the active galactic nucleus Mkn 501 for a possible correlation with
energy, as suggested by some models of quantum gravity (QG), which predict a
vacuum refractive index \simeq 1 + (E/M_{QGn})^n, n = 1,2. Parametrizing the
delay between gamma-rays of different energies as \Delta t =\pm\tau_l E or
\Delta t =\pm\tau_q E^2, we find \tau_l=(0.030\pm0.012) s/GeV at the 2.5-sigma
level, and \tau_q=(3.71\pm2.57)x10^{-6} s/GeV^2, respectively. We use these
results to establish lower limits M_{QG1} > 0.21x10^{18} GeV and M_{QG2} >
0.26x10^{11} GeV at the 95% C.L. Monte Carlo studies confirm the MAGIC
sensitivity to propagation effects at these levels. Thermal plasma effects in
the source are negligible, but we cannot exclude the importance of some other
source effect.Comment: 12 pages, 3 figures, Phys. Lett. B, reflects published versio
Estimation of transpiration of the 'Valencia' orange young plant using thermal dissipation probe method
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
Presencia de metales pesados en Pato Mexicano (Anas diazi Ridgway)
Resumen
Objetivo: identificar la presencia de metales pesados en órganos de Anas diazi (pato mexicano).
Metodología/diseño: Revisión bibliográfica de publicaciones científicas.
Resultados:
Los metales pesados son partículas que se bioacumulan en los organismos, estos tienen repercusiones negativas a la salud, tales como afectar el crecimiento y desarrollo adecuado de los mismos. Para el estudio y análisis de partículas toxicas como los metales pesados se monitorea en su mayoría aves acuáticas.Estas aves habitan en humedales que se ven afectados por la presencia de metales pesados debido a las actividades antropogénicas desarrolladas cerca de estos, tales como la ganadería, la industria y la caza furtiva de anátidos. Una de las cinco especies de anátidos registrados en México es Anas diazi que habita en el altiplano centro y norte de México.Los principales metales pesados a los que están expuestos los anátidos son mercurio, arsénico, plomo y cromo.
Limitaciones del estudio /implicaciones: La contaminación por metales pesados se ha convertido en un problema de salud pública muy importante, dado el alto grado de gravedad o repercusión en los animales, plantas, agua, suelo, aire y el humano, teniendo como resultado afectaciones en la salud del organismo.
Hallazgos/conclusiones: Se requieren implementar medidas de remediación en los humedales y exigir a las autoridades ambientales que se hagan cargo del asunto, exigiendo propuestas para la disminución de contaminación a industrias, minas o cualquier fuete de contaminación al medio ambiente por metales pesados
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