171 research outputs found

    Spin-wave spectrum of copper metaborate in the commensurate phase 10K<T<21K

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    We have investigated the spin-wave spectrum of copper metaborate, CuB2_2O4_4, by means of inelastic neutron scattering in the commensurate magnetic phase. We have found two branches of spin-wave excitations associated with the two magnetic sublattices Cu(A) and Cu(B), respectively. In the temperature regime 10KT21K10K \le T \le 21K, where only the Cu(A) magnetic moments are ordered, the interaction between the two sublattices is found to be negligible. With this approximation we have determined the `easy plane' exchange parameters of the Cu(A) subsystem within standard spin-wave theory.Comment: 4 figure

    Lieb-Robinson Bounds for Spin-Boson Lattice Models and Trapped Ions

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    We derive a Lieb-Robinson bound for the propagation of spin correlations in a model of spins interacting through a bosonic lattice field, which satisfies a Lieb-Robinson bound in the absence of spin-boson couplings. We apply these bounds to a system of trapped ions and find that the propagation of spin correlations, as mediated by the phonons of the ion crystal, can be faster than the regimes currently explored in experiments. We propose a scheme to test the bounds by measuring retarded correlation functions via the crystal fluorescence

    Comparación de frecuencias alélicas y genotípicas de los polimorfismos CAPN1-316 Y CAPN1-4751 del gen de la Calpaina en tres poblaciones de ganado criollo boliviano

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    La terneza de la carne está en parte determinada por el sistema proteico calpaína (CAPN1) / calpastatina (CAST). Bolivia posee en los llanos tres biotipos de ganado Criollo: los Yacumeños, los Chaqueños y los Saavedreños. El objetivo del presente trabajo fue determinar la frecuencia alélica y genotípica del gen de la CAPN1 en tres poblaciones de ganado Criollo de Bolivia. Se obtuvieron muestras de sangre de 28 Criollos del Chaco (CCH), 85 Criollos Yacumeños (CYA) y 30 Criollos Saavedreños (CSV). El ADN se extrajo utilizando el kit comercial Wizard® Genomic Purification, y posteriormente se tipificaron dos polimorfismos (CAPN1-316 y CAPN1-4751) del gen CAPN1 mediante el método ARMS-PCR. La frecuencias alélicas y genotípicas, las heterocigosidades esperadas y observadas, así como, el índice FIS y el desequilibrio de ligamiento (LD) fueron calculadas mediante los programas MS-Tools y Genepop. Las frecuencias de los alelos asociados a mayor terneza para las poblaciones de CCH, CYA y CSV fueron: 23%, 22% y 33 % para el alelo C del SNP CAPN1-316 y 75%, 76% y 60% para el alelo C del CAPN1-4751. La heterocigocidad observada en las tres poblaciones se hallan en un rango de 0,30 a 0,46 para el marcador CAPN1-316 y de 0,21 a 0,60 para el polimorfismo CAPN1-4751. Los resultados demuestran que los bovinos criollos en las poblaciones analizadas poseen altas frecuencias alélicas para las variantes asociadas a mayor terneza de la carne. Por otra parte, no se observaron valores significativos de LD (P>0,01) entre los dos polimorfismos tipificados en las poblaciones estudiadas. Sería necesario tipificar ambos polimorfismos en futuros programas de selección asistida por marcadores genéticos.Meat tenderness is in part determined by the calpain (CAPN1) / calpastatin (CAST) genes. In the lowlands of Bolivia, three well differentiated Creole cattle populations can be distinguished: the Yacumeños, Chaqueños and Saavedreños. The main objective of this research was to determine the allelic and genotypic frequencies of two polymorphisms of the calpain gene in three Creole cattle populations in Bolivia. Blood samples of 28 Creole cattle from Chaqueño cattle (CCH), 85 from Yacumeño cattle (CYA) and 30 from Saavadreño cattle (CSV) were collected. Total DNA was extracted using the commercial kit Wizard® Genomic Purification and subsequently two polymorphisms (CAPN1-316 and CAPN1- 4751) of the CAPN1 gene were genotyped by the amplification refractory mutation system (ARMS-PCR) method. Allelic and genotypic frequencies, expected and observed heterozygosities, the FIS index and the magnitude of linkage disequilibrium (LD) were calculated using the software MS-Tools and Genepop. The allelic frequencies of variants associated with tenderness in the three populations CCH, CYA and CSV were 23%, 22% and 23% for the CAPN1- 316 and 75%, 76% and 60% for the CAPN1-4751. The observed heterozygosities in the three populations fluctuated between 0.30 and 0.46 for the CAPN1-316 marker and between 0.21 and 0.60 for the CAPN1-4751 marker. The results showed that the analysed populations of Creole cattle presented high frequencies of the alleles previously associated with tenderness in meat. The analysis of LD, however, did not show evidence of linkage between the two markers. It is necessary to perform a genetic analysis for both polymorphisms if included in future selection programs.Fil: Pereira, J. A. C.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Falomir Lockhart, Agustin Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Loza, A.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Villegas Castagnasso, Egle Etel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Rojas, P.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Carino, M. . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Ripoli, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Giovambattista, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin

    Design of a conservation program assited by genetic markers in a herd of Yacumeño cattle in Santa Cruz – Bolivia

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    La Facultad de Ciencias Veterinarias de la UAGRM consolido un programa de conservación del ganado Bovino Criollo Yacumeño a partir del año 2004. La conservación de recursos zoogenéticos generalmente se realiza en poblaciones pequeñas, las cuales tienen un tamaño poblacional efectivo muy reducido. En estos casos es importante realizar apareamientos que mantengan la variabilidad genética alta y los niveles de consanguinidad bajos. El objetivo del presente trabajo consistió en determinar las paternidades y los linajes paternos mediante el uso de marcadores moleculares. El ADN se extrajo partir de muestras de sangre de los 149 animales del hato y se procedió a genotipificar todos los individuos utilizando 18 microsatélites y 7 marcadores del cromosoma Y. Los resultados obtenidos permitieron identificar dos grandes grupos de vacas y 3 linajes paternos. Esta información servirá para diseñar un programa reproductivo que evite en lo posible la perdida de la variabilidad genética y mantenga niveles aceptables de consaguinidad en el hato a conservar.The Faculty of Veterinary Science of the UAGRM consolidated a conservation program of the Yacumeño Creole cattle. The conservation of zoogenetic resources is performed generally in small populations, which usually has a reduced effective population size. In those cases it is important to keep high genetic variability and low levels of consanguinity by performing specific mating among the animals. The main objective of this research consisted in determine the paternity and male lines by using molecular markers. The DNA was extracted from blood sample of 149 animals and were genotyped all the individuals using 18 microsatellites and 7 markers of the Y chromosome. The results obtained allowed to identify two groups of cows and 3 male lines. This information will be useful to design a reproductive program that avoids to a certain degree the lost of genetic variability and will keep acceptable levels of consanguinity among the herd.Fil: Pereira, J. A. C.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Carino, M. H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Hoyos, R.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Rogberg Muñoz, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Loza, A.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Liron, Juan Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Mamani, T.. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Ripoli, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Giovambattista, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin

    Association between GNRHR, LHR and IGF1 polymorphisms and timing of puberty in male Angus cattle

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    <p>Abstract</p> <p>Background</p> <p>In bovines, there are significant differences within and among beef breeds in the time when bulls reach puberty. Although the timing of puberty is likely to be a multigenic trait, previous studies indicate that there may also be single genes that exert major effects on the timing of puberty within the general population. Despite its economic importance, there are not many SNPs or genetic markers associated with the age of puberty in male cattle. In the present work, we selected three candidate genes, <it>GNRHR</it>, <it>LHR </it>and <it>IGF1</it>, and associated their polymorphisms with the age of puberty in Angus male cattle.</p> <p>Results</p> <p>After weaning, 276 Angus males were measured every month for weight (W), scrotal circumference (SC), sperm concentration (C) and percentage of motility (M). A total of 4 SNPs, two within <it>GNRHR</it>, one in <it>LHR </it>and one in <it>IGF1 </it>were genotyped using the pyrosequencing technique. <it>IGF1-SnaBI SNP </it>was significant associated (P < 0.01) with age at SC 28 cm, but it were not associated with age at M 10% and C 50 million. Genotype <it>CC </it>exhibited an average age at SC 28 cm of 7 and 11 days higher than <it>CT </it>(p = 0.037) and <it>TT </it>(p = 0.012), respectively. This SNP explained 1.5% of the genetic variance of age of puberty at SC28. <it>LHR-I499L</it>, <it>GNRHR-SNP5 </it>and <it>GNRHR-SNP6 </it>were not associated with any of the measurements. However, <it>GNRHR </it>haplotypes showed a suggestive association with age at SC 28 cm.</p> <p>Conclusions</p> <p>The findings presented here could support the hypothesis that <it>IGF1 </it>is a regulator of the arrival to puberty in male calves and is involved in the events that precede and initiate puberty in bull calves. Given that most studies in cattle, as well as in other mammals, were done in female, the present results are the first evidence of markers associated with age at puberty in male cattle.</p

    TOpic: rare and special cases, the real "Strange cases"

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    Introduction: The bladder hernia represents approximately 1-3% of all inguinal hernias, where patients aged more than 50 years have a higher incidence (10%). Many factors contribute to the development of a bladder hernia, including the presence of a urinary outlet obstruction causing chronic bladder distention, the loss of bladder tone, pericystitis, the perivesical bladder fat protrusion and the obesity

    Mediciones de dióxido de azufre en aire mediante métodos activos y pasivos

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    El trabajo tiene como objetivos el estudio, desarrollo y aplicación de técnicas para la medición de contaminantes atmosféricos derivados del azufre en zonas de La Plata y alrededores del Polo Petroquímico mediante métodos activos y pasivos. En la obtención de datos sobre concentranciones de dióxido de azufre se utiliza un método activo, el analizador de SO₂ por fluorescencia en el UV. Los datos logrados se comparan con los que se obtienen utilizando técnicas pasivas de medición química y biológicas, tales como la tasa de sulfatación, que se constituye en uno de los indicadores válidos para estimar el estado general del aire en una zona determinada y la comparación de la flora liquénica de las areas en estudio con la de otras no contaminadas. Todas las determinaciones se correlacionan con los factores climáticos y además, para que resulten comparativas en sí mismas, se efectúan en diversas zonas consideradas de "mayor riesgo", que se contrastan con otras. consideradas de "bajo riesgo".Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

    Greenhouse gas emission associated with sugar production in southern Brazil

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    <p>Abstract</p> <p>Background</p> <p>Since sugarcane areas have increased rapidly in Brazil, the contribution of the sugarcane production, and, especially, of the sugarcane harvest system to the greenhouse gas emissions of the country is an issue of national concern. Here we analyze some data characterizing various activities of two sugarcane mills during the harvest period of 2006-2007 and quantify the carbon footprint of sugar production.</p> <p>Results</p> <p>According to our calculations, 241 kg of carbon dioxide equivalent were released to the atmosphere per a ton of sugar produced (2406 kg of carbon dioxide equivalent per a hectare of the cropped area, and 26.5 kg of carbon dioxide equivalent per a ton of sugarcane processed). The major part of the total emission (44%) resulted from residues burning; about 20% resulted from the use of synthetic fertilizers, and about 18% from fossil fuel combustion.</p> <p>Conclusions</p> <p>The results of this study suggest that the most important reduction in greenhouse gas emissions from sugarcane areas could be achieved by switching to a green harvest system, that is, to harvesting without burning.</p

    Design of a Conservation Program Assited by Genetic Markers in a Herd of YacumeñO Cattle in Santa Cruz – Bolivia

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    La Facultad de Ciencias Veterinarias de la UAGRM consolido un programa de conservación del ganado Bovino Criollo Yacumeño a partir del año 2004. La conservación de recursos zoogenéticos generalmente se realiza en poblaciones pequeñas, las cuales tienen un tamaño poblacional efectivo muy reducido. En estos casos es importante realizar apareamientos que mantengan la variabilidad genética alta y los niveles de consanguinidad bajos. El objetivo del presente trabajo consistió en determinar las paternidades y los linajes paternos mediante el uso de marcadores moleculares. El ADN se extrajo partir de muestras de sangre de los 149 animales del hato y se procedió a genotipificar todos los individuos utilizando 18 microsatélites y 7 marcadores del cromosoma Y. Los resultados obtenidos permitieron identificar dos grandes grupos de vacas y 3 linajes paternos. Esta información servirá para diseñar un programa reproductivo que evite en lo posible la perdida de la variabilidad genética y mantenga niveles aceptables de consaguinidad en el hato a conservar.The Faculty of Veterinary Science of the UAGRM consolidated a conservation program of the Yacumeño Creole cattle. The conservation of zoogenetic resources is performed generally in small populations, which usually has a reduced effective population size. In those cases it is important to keep high genetic variability and low levels of consanguinity by performing specific mating among the animals. The main objective of this research consisted in determine the paternity and male lines by using molecular markers. The DNA was extracted from blood sample of 149 animals and were genotyped all the individuals using 18 microsatellites and 7 markers of the Y chromosome. The results obtained allowed to identify two groups of cows and 3 male lines. This information will be useful to design a reproductive program that avoids to a certain degree the lost of genetic variability and will keep acceptable levels of consanguinity among the herd.Instituto de Genética Veterinari
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