Stationary waves and slowly moving features in the night upper clouds of Venus

At the cloud top level of Venus (65-70 km altitude) the atmosphere rotates 60 times faster than the underlying surface, a phenomenon known as superrotation. Whereas on Venus's dayside the cloud top motions are well determined and Venus general circulation models predict a mean zonal flow at the upper clouds similar on both day and nightside, the nightside circulation remains poorly studied except for the polar region. Here we report global measurements of the nightside circulation at the upper cloud level. We tracked individual features in thermal emission images at 3.8 and 5.0 $\mathrm{\mu m}$ obtained between 2006 and 2008 by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS-M) onboard Venus Express and in 2015 by ground-based measurements with the Medium-Resolution 0.8-5.5 Micron Spectrograph and Imager (SpeX) at the National Aeronautics and Space Administration Infrared Telescope Facility (NASA/IRTF). The zonal motions range from -110 to -60 m s$^{-1}$, consistent with those found for the dayside but with larger dispersion. Slow motions (-50 to -20 m s$^{-1}$) were also found and remain unexplained. In addition, abundant stationary wave patterns with zonal speeds from -10 to +10 m s$^{-1}$ dominate the night upper clouds and concentrate over the regions of higher surface elevation.Comment: 15 pages, 4 figures, 6 supplementary figure

Progesterona en leche, 2. Parámetros reproductivos evaluados mediante el análisis de progesterona en leche.

Se estudió en un grupo de 44 vacas la correlación de los perfiles típicos y atípicos, anestros e índices de preñez, diagnóstico precoz de preñez, incidencia de inseminaciones y ovulaciones perdidas, mediante la determinación de progesterona en leche por radioinmunoanálisis. Estos análisis se hicieron en el laboratorio de hormonas del Instituto de Asuntos Nucleares. Se estableció un criterio para definir si un perfil progestacional era típico o atípico, encontrando que las vacas con perfil progestacional tienden a presentar menos días abiertos. El promedio de días abiertos para las vacas con perfil progestacional típico fue de 161 y para aquellas con perfil progestacional atípico fue de 310. La duración del período anestro no difirió notablemente entre vacas preñadas y no preñadas. El índice de precisión para el diagnóstico precoz (21 días) de preñez fue positivo del 78 por ciento, mientras que para el negativo (vacas vacias) fue del 99 por ciento. El día post-inseminación más adecuado para la toma de muestra utilizada en este diagnóstico de preñez fue el día 21, aunque la diferencia no fue significativa con referencia a los días 19 y 23. El método permitió medir el número de inseminaciones y ovulaciones perdidasGanado de leche-Ganadería lech

Progesterona en leche, 1. Radio inmuno análisis de progesterona en leche.

Se desarrolló un método de análisis de progesterona en leche por RIA. En la estandarización de la técnica el tiempo de incubación antígeno-anticuerpo se redujo a 10 minutos. La leche dentro del sistema actuó como ligante no específico de la progesterona. Este efecto fue superado mediante la escogencia de una alicuota (10 ul) adecuada y la correlación introducida en la curva de calibración al adicionarle leche sin hormona detectable. La alícuota de 10 ul mencionada anteriormente contiene cantidades medibles dentro de los límites de máxima resolución del método (6,25 - 400 pg 0.1 ml). El uso de una suspensión de carbón-dextrano para la separación de la fracción libre y ligada no pudo ser sustituido por el de un segundo antisuero. Los valores en la leche se correlacionaron en forma altamente significativa con la existente en la sangre, no obstante, las concentraciones en leche fueron 5,2 veces más altas que en sangre. Estas dos circunstancias han ampliado la aplicabilidad y sensibilidad del método. Mediante análisis estadístico de datos allegados durante dos años, se comprobó la sensibilidad reproductiva y precisiónGanado de leche-Ganadería lech

Effects of seagrasses and algae of the Caulerpa family on hydrodynamics and particle-trapping rates

The widespread decline of seagrass beds within the Mediterranean often results in the replacement of seagrasses by opportunistic green algae of the Caulerpa family. Because Caulerpa beds have a different height, stiffness and density compared to seagrasses, these changes in habitat type modify the interaction of the seafloor with hydrodynamics, influencing key processes such as sediment resuspension and particle trapping. Here, we compare the effects on hydrodynamics and particle trapping of Caulerpa taxifolia, C. racemosa, and C. prolifera with the Mediterranean seagrasses Cymodocea nodosa and Posidonia oceanica. All macrophyte canopies reduced near-bed volumetric flow rates compared to bare sediment, vertical profiles of turbulent kinetic energy revealed peak values around the top of the canopies, and maximum values of Reynolds stress increased by a factor of between 1.4 (C. nodosa) and 324.1 (P. oceanica) when vegetation was present. All canopies enhanced particle retention rates compared to bare sediment. The experimental C. prolifera canopy was the most effective at particle retention (m2 habitat); however, C. racemosa had the largest particle retention capacity per structure surface area. Hence, in terms of enhancing particle trapping and reducing hydrodynamic forces at the sediment surface, Caulerpa beds provided a similar or enhanced function compared to P.oceanica and C. nodosa. However, strong seasonality in the leaf area index of C. racemosa and C. taxifolia within the Mediterranean, combined with a weak rhizome structure, suggests that sediments maybe unprotected during winter storms, when most erosion occurs. Hence, replacement of seagrass beds with Caulerpa is likely to have a major influence on annual sediment dynamics at ecosystem scales.This research was funded by the European Network of Excellence ‘‘Marine Biodiversity and Ecosystem Function’’ (MarBEF); FP6, EC contract no. 505446 and a grant from the Fundacio ´n BBVA. EPM was supported by a European Union Marie Curie host fellowship for transfer of knowledge, MTKD-CT-2004-509254, the Spanish national project EVAMARIA (CTM2005-00395/MAR) and the regional government of Andalusia project FUNDIV(P07-RNM-2516)

Evaluación física y clínica de sementales bovinos en dos municipios de la costa chica de Guerrero, México

Objective: To evaluate the reproductive physical characteristics and general health of stallions in two municipalities of Costa Chica of Guerrero, Mexico. Design/methodology/approach: The study was carried out in the municipalities of Ometepec and Cuajinicuilapa. Thirty bulls between 2 and 10 years of age were evaluated. In the physical reproductive and clinical examination were performed by direct observation, using ultrasound to evaluate attached reproductive glands and testicular parenchyma. Blood samples were taken to determine the blood profile. Descriptive statistics was used to present the results. Results: The 86% of the bulls had adequate legs and feet as well as preputial length. Scrotal circumference was according to the age and breed of the animals. Testicular defects were showed for 30% of the bulls, the most common was hypoplasia and unilateral tumors of testicular parenchyma and epididymis, as well as calcifications of the testicular parenchyma. The 93% of the bulls had normal accessory genital glands. Clinically 24% of the bulls with signs suggestive of anaplasmosis were found. The 76% of the bulls, apparently healthy, presented monocytosis, thrombocytopenia and anemia. Limitations on study/implications: the lack of knowledge of the producers about the need for a comprehensive evaluation of the bulls allows them to suffer from diseases without receiving any type of treatment, decreasing their reproductive efficiency. Findings/conclusions: Most of the bulls evaluated had the minimum physical characteristics required, although the presence of anemia and respiratory diseases may have an indirect negative impact on the reproductive efficiency of the bulls.Objetivo: Evaluar las características físicas reproductivas y la salud general de los sementales en dos municipios de Costa Chica de Guerrero, México. Diseño/metodología/aproximación: Se evaluaron reproductiva y clínicamente 30 sementales, de entre 2 y 10 años. El examen reproductivo, se realizó por observación directa, empleándose ecografía para evaluar glándulas reproductivas anexas y el parénquima testicular. La evaluación clínica se realizó por medio del examen físico y perfil hemático. Se empleó estadística descriptiva para la presentación de los resultados. Resultados: El 86% de los sementales tuvieron aplomos y largo prepucial adecuado, así como circunferencia escrotal acorde a la edad y raza de los animales. El 30% de los sementales presentaron defectos testiculares, siendo los más comunes, hipoplasia y tumores unilaterales de parénquima testicular y epidídimos, así como calcificaciones del parénquima testicular. El 93% de las glándulas anexas fueron normales. Clínicamente se encontró un 24% de los sementales con signos sugerentes a anaplasmosis. El 76% de los toros, aparentemente sanos, presentaron monocitosis, trombocitopenia y anemia. Limitaciones del estudio/implicaciones: El desconocimiento de los productores sobre la necesidad de una evaluación integral de los sementales permite que éstos padezcan enfermedades que no son tratadas, disminuyendo su eficiencia reproductiva. Hallazgos/conclusiones: La mayoría de los sementales evaluados tuvieron las características físicas mínimas requeridas, aunque la presencia de anemia y enfermedades respiratorias pueden tener incidencia negativa indirecta sobre la eficiencia reproductiva de los sementales

Learning curves of basic laparoscopic psychomotor skills in SINERGIA VR simulator

Purpose: Surgical simulators are currently essential within any laparoscopic training program because they provide a low-stakes, reproducible and reliable environment to acquire basic skills. The purpose of this study is to determine the training learning curve based on different metrics corresponding to five tasks included in SINERGIA laparoscopic virtual reality simulator. Methods: Thirty medical students without surgical experience participated in the study. Five tasks of SINERGIA were included: Coordination, Navigation, Navigation and touch, Accurate grasping and Coordinated pulling. Each participant was trained in SINERGIA. This training consisted of eight sessions (R1–R8) of the five mentioned tasks and was carried out in two consecutive days with four sessions per day. A statistical analysis was made, and the results of R1, R4 and R8 were pair-wise compared with Wilcoxon signed-rank test. Significance is considered at P value <0.005. Results: In total, 84.38% of the metrics provided by SINERGIA and included in this study show significant differences when comparing R1 and R8. Metrics are mostly improved in the first session of training (75.00% when R1 and R4 are compared vs. 37.50% when R4 and R8 are compared). In tasks Coordination and Navigation and touch, all metrics are improved. On the other hand, Navigation just improves 60% of the analyzed metrics. Most learning curves show an improvement with better results in the fulfillment of the different tasks. Conclusions: Learning curves of metrics that assess the basic psychomotor laparoscopic skills acquired in SINERGIA virtual reality simulator show a faster learning rate during the first part of the training. Nevertheless, eight repetitions of the tasks are not enough to acquire all psychomotor skills that can be trained in SINERGIA. Therefore, and based on these results together with previous works, SINERGIA could be used as training tool with a properly designed training program

A few StePS forward in unveiling the complexity of galaxy evolution: Light-weighted stellar ages of intermediate-redshift galaxies with WEAVE

The upcoming new generation of optical spectrographs on four-meter-class telescopes will provide invaluable information for reconstructing the history of star formation in individual galaxies up to redshifts of about 0.7. We aim at defining simple but robust and meaningful physical parameters that can be used to trace the coexistence of widely diverse stellar components: younger stellar populations superimposed on the bulk of older ones. We produce spectra of galaxies closely mimicking data from the forthcoming Stellar Populations at intermediate redshifts Survey (StePS), a survey that uses the WEAVE spectrograph on the William Herschel Telescope. First, we assess our ability to reliably measure both ultraviolet and optical spectral indices in galaxies of different spectral types for typically expected signal-to-noise levels. Then, we analyze such mock spectra with a Bayesian approach, deriving the probability density function of r- and u-band light-weighted ages as well as of their difference. We find that the ultraviolet indices significantly narrow the uncertainties in estimating the r- and u-band light-weighted ages and their difference in individual galaxies. These diagnostics, robustly retrievable for large galaxy samples even when observed at moderate signal-to-noise ratios, allow us to identify secondary episodes of star formation up to an age of ~0.1 Gyr for stellar populations older than ~1.5 Gyr, pushing up to an age of ~1 Gyr for stellar populations older than ~5 Gyr. The difference between r-band and u-band light-weighted ages is shown to be a powerful diagnostic to characterize and constrain extended star-formation histories and the presence of young stellar populations on top of older ones. This parameter can be used to explore the interplay between different galaxy star-formation histories and physical parameters such as galaxy mass, size, morphology, and environment

Systems and technologies for objective evaluation of technical skills in laparoscopic surgery

Minimally invasive surgery is a highly demanding surgical approach regarding technical requirements for the surgeon, who must be trained in order to perform a safe surgical intervention. Traditional surgical education in minimally invasive surgery is commonly based on subjective criteria to quantify and evaluate surgical abilities, which could be potentially unsafe for the patient. Authors, surgeons and associations are increasingly demanding the development of more objective assessment tools that can accredit surgeons as technically competent. This paper describes the state of the art in objective assessment methods of surgical skills. It gives an overview on assessment systems based on structured checklists and rating scales, surgical simulators, and instrument motion analysis. As a future work, an objective and automatic assessment method of surgical skills should be standardized as a means towards proficiency-based curricula for training in laparoscopic surgery and its certification

<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data

Open and Hidden Charm Production in 920 GeV Proton-Nucleus Collisions

The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B spectrometer covers negative values of xF up to xF=-0.3 and a broad range in transverse momentum from 0.0 to 4.8 GeV/c. The studies presented in this paper include J/psi differential distributions and the suppression of J/psi production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.Comment: 5 pages, 9 figures, to be published in the proceedings of the 6th International Conference on Hyperons, Charm & Beauty Hadrons (BEACH04), Chicago, IL, June 27 - July 3, 200