141 research outputs found
Glory revealed in disk-integrated photometry of Venus
Context. Reflected light from a spatially unresolved planet yields unique
insight into the overall optical properties of the planet cover. Glories are
optical phenomena caused by light that is backscattered within spherical
droplets following a narrow distribution of sizes; they are well known on Earth
as localised features above liquid clouds. Aims. Here we report the first
evidence for a glory in the disk-integrated photometry of Venus and, in turn,
of any planet. Methods. We used previously published phase curves of the planet
that were reproduced over the full range of phase angles with model predictions
based on a realistic description of the Venus atmosphere. We assumed that the
optical properties of the planet as a whole can be described by a uniform and
stable cloud cover, an assumption that agrees well with observational evidence.
Results. We specifically show that the measured phase curves mimic the
scattering properties of the Venus upper-cloud micron-sized aerosols, also at
the small phase angles at which the glory occurs, and that the glory contrast
is consistent with what is expected after multiple scattering of photons. In
the optical, the planet appears to be brighter at phase angles of 11-13 deg
than at full illumination; it undergoes a maximum dimming of up to 10 percent
at phases in between. Conclusions. Glories might potentially indicate spherical
droplets and, thus, extant liquid clouds in the atmospheres of exoplanets. A
prospective detection will require exquisite photometry at the small
planet-star separations of the glory phase angles.Comment: In press. Astronomy & Astrophysics. Letter to the Editor; 201
Multilayer hazes over Saturn’s hexagon from Cassini ISS limb images
Producción CientíficaVer abstract
Interstitial Cells of Cajal and Enteric Nervous System in Gastrointestinal and Neurological Pathology, Relation to Oxidative Stress
The enteric nervous system (ENS) is organized into two plexuses-submucosal and myenteric-which regulate smooth muscle contraction, secretion, and blood flow along the gastrointestinal tract under the influence of the rest of the autonomic nervous system (ANS). Interstitial cells of Cajal (ICCs) are mainly located in the submucosa between the two muscle layers and at the intramuscular level. They communicate with neurons of the enteric nerve plexuses and smooth muscle fibers and generate slow waves that contribute to the control of gastrointestinal motility. They are also involved in enteric neurotransmission and exhibit mechanoreceptor activity. A close relationship appears to exist between oxidative stress and gastrointestinal diseases, in which ICCs can play a prominent role. Thus, gastrointestinal motility disorders in patients with neurological diseases may have a common ENS and central nervous system (CNS) nexus. In fact, the deleterious effects of free radicals could affect the fine interactions between ICCs and the ENS, as well as between the ENS and the CNS. In this review, we discuss possible disturbances in enteric neurotransmission and ICC function that may cause anomalous motility in the gut.info:eu-repo/semantics/publishedVersio
Interstitial cells of Cajal and enteric nervous system in gastrointestinal and neurological pathology. Relation to oxidative stress
The enteric nervous system (ENS) is organized into two plexuses—submucosal and myenteric—which regulate smooth muscle contraction, secretion, and blood flow along the gastrointestinal tract under the influence of the rest of the autonomic nervous system (ANS). Interstitial cells of Cajal (ICCs) are mainly located in the submucosa between the two muscle layers and at the intramuscular level. They communicate with neurons of the enteric nerve plexuses and smooth muscle fibers and generate slow waves that contribute to the control of gastrointestinal motility. They are also involved in enteric neurotransmission and exhibit mechanoreceptor activity. A close relationship appears to exist between oxidative stress and gastrointestinal diseases, in which ICCs can play a prominent role. Thus, gastrointestinal motility disorders in patients with neurological diseases may have a common ENS and central nervous system (CNS) nexus. In fact, the deleterious effects of free radicals could affect the fine interactions between ICCs and the ENS, as well as between the ENS and the CNS. In this review, we discuss possible disturbances in enteric neurotransmission and ICC function that may cause anomalous motility in the gut
Design of a conservation program assited by genetic markers in a herd of Yacumeño cattle in Santa Cruz – Bolivia
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
Fauna de insectos hematófagos del sur del Parque Natural Nacional Chiribiquete, Caquetá, Colombia
As part of the management and conservation study at the Chiribiquete National Natural Park developed by the Puerto Rastrojo Foundation, an entomological study was done at the Puerto Abeja Biological Station (Mesay river, Solano municipality, Caqueta department). Jaccard similarity index, Shannon-Vileaver diversity index and attacks rates were calculated for diurnal diptera in each of the six forests evaluated. 31 species of Culicidae, 1 of Triatominae, 1 of Ceratopogonidae, 2 of Simuliidae. 10 of Phlebotomine and 6 of Tabanidae were reported. Three new Culicidae species were reported for Colombia: Sabethes glaucodaemon. Trichoprosopon espini and Uranotaenia pallidoventer and the Caqueta department hematophagous insect's distribution was enlarged. Diurna1 species activity and association between species and forests was obtained. Control measures were recommended aimed at preventing vectorial tropical diseases transmission and the epidemiological importante of potential vectors captured in the area was highlighted.Como parte del estudio para el manejo y la conservación del Parque Natural Nacional Chiribiquete, desarrollado por la Fundación Puerto Rastrojo, se realizó un inventario de la fauna entomológica hematófaga en la estación biológica de Puerto Abeja (rio Mesay, municipio de Solano, departamento de Caquetá). Se calcularon los índices de similitud de Jaccard y el indice de diversidad de Shannon-Weaver y se determinaron los patrones de picadura de los dipteros diurnos para los seis tipos de bosques evaluados. Se registraron 31 especies de Culicidae, 1 de Triatominae, 1 de Ceratopogonidae, 2 de Simuliidae, 10 de Phlebotominae y 6 de Tabanidae. Se obtuvieron tres nuevos registros de especies de Culicidae para Colombia: Sabethes glaucodaemon, Trichoprosopon espini y Uranotaenia pallidoventer; y se amplió el registro de varios insectos hematófagos en el departamento de Caquetá. Se presentan los patrones de actividad de las especies diurnas y su relación con los tipos de bosque y se sugieren posibles medidas de control para evitar enfermedades transmitidas por diferentes vectores, resaltando la importancia epidemiológica de las especies capturadas que presentan capacidad vectorial
Design of a Conservation Program Assited by Genetic Markers in a Herd of YacumeñO Cattle in Santa Cruz – Bolivia
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
Design of a Conservation Program Assited by Genetic Markers in a Herd of YacumeñO Cattle in Santa Cruz – Bolivia
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
Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study
The VESSEL12 (VESsel SEgmentation in the Lung) challenge objectively compares the performance of different algorithms to identify vessels in thoracic computed tomography (CT) scans. Vessel segmentation is fundamental in computer aided processing of data generated by 3D imaging modalities. As manual vessel segmentation is prohibitively time consuming, any real world application requires some form of automation. Several approaches exist for automated vessel segmentation, but judging their relative merits is difficult due to a lack of standardized evaluation. We present an annotated reference dataset containing 20 CT scans and propose nine categories to perform a comprehensive evaluation of vessel segmentation algorithms from both academia and industry. Twenty algorithms participated in the VESSEL12 challenge, held at International Symposium on Biomedical Imaging (ISBI) 2012. All results have been published at the VESSEL12 website http://vessel12.grand-challenge.org. The challenge remains ongoing and open to new participants. Our three contributions are: (1) an annotated reference dataset available online for evaluation of new algorithms; (2) a quantitative scoring system for objective comparison of algorithms; and (3) performance analysis of the strengths and weaknesses of the various vessel segmentation methods in the presence of various lung diseases.Rudyanto, RD.; Kerkstra, S.; Van Rikxoort, EM.; Fetita, C.; Brillet, P.; Lefevre, C.; Xue, W.... (2014). Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study. Medical Image Analysis. 18(7):1217-1232. doi:10.1016/j.media.2014.07.003S1217123218
- …