El manejo estratégico del amamantamiento mejora el porcentaje de preñez en sistemas de producción bovina de doble propósito y cría libre

La tasa de natalidad es un indicador útil para saber cómo funciona la reproducción en una empresa ganadera. Algunos estudios realizados en la región Caribe han reportado tasas de natalidad del 66.3% y del 68.8%. El análisis de la información disponible revela que en los últimos 20 años no existen importantes progresos en relación con la eficiencia reproductiva de los hatos en esta zona del país.Ganado de doble propósito-Ganaderia doble propositoEstrategias de manejo de la hembra bovina para reducir el anestro posparto mediante sistemas de interrupción temporal del amamantamient

Retrievals of the main phytoplankton groups at Lake Constance using OLCI, DESIS, and evaluated with field observations

Phytoplankton play an important role in the aquatic biogeochemical cycling such as for the formation of organic matter by photosynthetic processes through the fixation of carbon dioxide, and assimilation of macro- and micronutrients depending on their metabolic needs. These processes are common to all phytoplankton, however some phytoplankton groups have specific needs and thus play different functional roles in the biogeochemical cycle, which are used to classify phytoplankton into different phytoplankton functional types (PFTs). Information on the phytoplankton groups can be obtained from satellite observations such as the Ocean and Land Colour Instrument (OLCI) onboard of ISS and Sentinel-3. PFTs global ocean abundance can be estimated based on the OC-PFT algorithm (Hirata et al. 2011 and related updates to it) which is based on the assumption that a marker pigment for a specific PFT varies in dependence to the chlorophyll-a concentration. In this study, OC-PFT retrieval has been developed and adapted for estimation of PFT from Lake Constance by using a large collection of in-situ HPLC data set measured since 2000 at the largest German inland water by the regional authority and further analysed to derive PFT using the diagnostic pigment analysis following Vidussi et al. (2001) with adapted coefficients for Lake Constance. The PFT retrieved from OLCI are validated using independent in situ data derived from HPLC pigment measurements from 4 field campaigns performed in 2019 and 2020 at Lake Constance. Concentrations for five phytoplankton groups (diatoms, dinoflagellates, cryptophytes, green algae, and prokaryotes) are retrieved for Lake Constance, being the dominants diatoms and cryptophytes and at lesser degree green algae. In addition, evaluation of synergistic PFT products are presented to enlarge the capabilities of PFT data in inland and coastal waters analytically retrieved from high spectral and high spatial data such as DESIS, EnMAP or PRISMA by synergistic use with OLCI OC-PFT data sets is discussed

Development and simulation of an advanced system of ambient control in agricultural greenhouses

Production in greenhouses is a technique that aims at protecting flowers and vegetable production against meteorological agents that affect production adversely, as well as allowing favorable environments throughout the year with productive and commercial advantages. One important issue regarding greenhouse systems is the control of the air temperature and relative humidity. The automatic environmental control allows the improvement of quality, and the efficient and rational use of resources. The aim of this work was to develop a system of temperature and humidity control for a greenhouse prototype in reduced scale, by using the concepts of Fuzzy Logic. The input variables were: air temperature and humidity, and the output variables were: changes in the environmental heating system and humidification. The environmental control was simulated and project parameters were adjusted. The results of the simulation showed that the air temperature and humidity adjustment based on the inference developed Fuzzy system, was satisfactory for the performance of the greenhouse environmental control.A produção em ambientes protegidos é uma técnica por meio da qual se objetiva proteger flores e hortaliças contra a ação dos elementos meteorológicos que a afetam, além de permitir ambientes favoráveis de produção durante todo o ano, com vantagens produtivas e comerciais. Um fator importante da produção em estufas é o controle da temperaturae da umidade relativa do ar. A automação do controle do ambiente possibilita o aumento da qualidade dos produtos, maior eficiência e uso racional dos recursos. O objetivo do presente trabalho foi desenvolver um sistema de controle de temperatura e umidade relativa do ar para o protótipo de uma ambiente protegido em escala reduzida, utilizando-se dos conceitos da lógica Fuzzy. As variáveis de entrada foram a temperatura e a umidade do ar e as variáveis de saída foram as atuações nos sistemas de aquecimento e de umidificação do ambiente. O processo de controle do ambiente foi simulado e os parâmetros do projeto foram ajustados. Os resultados obtidos na simulação demonstraram que os ajustes das variáveis Tar e UR, baseados no sistema de inferência Fuzzy desenvolvido, foram satisfatórios para o desempenho do sistema de controle do ambiente protegido.1194120

Renovada sismicidad superficial en el oriente venezolano después del sismo de Cariaco de julio de 1997

This research shows a clear increase in shallow seismicity in the 21st century, after the Cariaco July 09th, 1997 earthquake, from the qualitative-quantitative analysis of a more than 30-year-long record of instrumental seismicity (1983-2017). The seismic activity increase is not randomly distributed but comes in patches, which align along with the El Pilar (FEP), Los Bajos (FLB), El Soldado (FES) and Bohordal (FB) faults, very particularly with their portions close or within the Paria gulf. Equally, this seismicity occurs South of the easternmost south-dipping FEP segment, and East of the San Juan Graben fault system. No major or destructive historical and instrumental earthquake is associated to this segment for the last 520 years. From the assumption that the contiguous-to-the-west FEP segment recurs roughly every 350-450 years with an Mw +7.0 event, we invoke that stress transfer from the recently-broken 1997 segment is responsible for the unusually high crustal seismicity happening in this 21st century, activating the easternmost FEP segment as well as the mechanically interconnected southern faults. This could lead to a major destructive (eventually  tsunamigenic) earthquake on FEP in the near future. On the other hand, the higher creep (50 over 40%) and slower slip rate (10 vs 12 mm/yr) of the easternmost segment than its western contiguous segment could account for the longer return period; longer than the 350-450 year return period determined from paleoseismic trench studies undertaken across the 1997 earthquake rupture. La presente investigación muestra que la región oriental venezolana se caracteriza por una mayor actividad sísmica en el presente siglo XXI, después de la ocurrencia del sismo de Cariaco del 09 de julio de 1997 de magnitud Mw 6,9, a partir del análisis cualitativo-cuantitativo de la sismicidad instrumental sobre una ventana temporal de más de 30 años (1983-2017). Este incremento de la actividad sísmica no es aleatorio y se presenta bajo “nubes” de sismos corticales que se alinean a lo largo de las fallas El Pilar (FEP), Los Bajos (FLB), El Soldado (FES) y Bohordal (FB), particularmente en sus porciones circunscritas al golfo de Paria. Igualmente, tal sismicidad se ubica al Sur del segmento más oriental de la FEP de buzamiento sur y al Este del sistema de fallas del Graben de San Juan. A este segmento de FEP se le desconoce sismo histórico, o instrumental, destructor, de profundidad cortical, sobre al menos 520 años. Dado que el segmento contiguo al Oeste de la FEP recurre cada 350-450 años con sismos Mw +7,0, cabe proponer que la sismicidad actual inusitada, sobre FEP y todas las fallas cuaternarias mecánicamente vinculadas a ellas, resulte de transferencia de esfuerzos de la ruptura reciente del segmento al Occidente en 1997, preparando al segmento más oriental de FEP para su eventual ruptura con un sismo de capacidad destructora, Mw +7,0, con eventual asociación de tsunami (sismo tsunamigénico). El hecho de presentar un porcentaje de movimiento asísmico (creep) más elevado que aquel roto durante el sismo de Cariaco de 1997 (50% vs 40%), así como una tasa de movimiento algo más lenta también (10 vs 12 mm/a), justificaría que su período de retorno sea algo más largo que 350-450 años; éste último estimado de evaluaciones paleosísmicas para el segmento activado en 1997.&nbsp

Determinación de la vida útil de una protección costera a través de la interacción oleaje-estructura

La vida útil de las estructuras costeras está en función de las fuerzas ejercidas por la acción combinada del oleaje y el nivel medio del mar. Sin embargo, el estudio de la interacción oleaje-estructura requiere conocer el papel de la rotura, el cual es en un fenómeno complejo que no se puede estudiar de forma analítica. Por tanto, en el presente trabajo propone extender una metodología existente para determinar la vida útil de los diques verticales, utilizando datos de un retroanálisis de oleaje y modelación numérica. Se empleó un algoritmo de máxima disimilitud para seleccionar 600 casos representativos de las condiciones de oleaje y nivel del mar en la zona de estudio, que fueron utilizados para el forzamiento de un modelo de propagación de oleaje. El modelo de propagación de oleaje se encadenó con un modelo no lineal, basado en las ecuaciones no hidrostáticas de aguas someras para calcular las fuerzas sobre la estructura y el rebase. Las fuerzas calculadas fueron utilizadas por un modelo de análisis estructural para cuantificar los movimientos asociados con la interacción oleaje-estructura. Los resultados de rebase y fuerzas fueron interpolados para las condiciones no modeladas, con el fin de reconstruir la serie temporal de 30 años. Estos resultados permiten caracterizar el fallo asociado con diferentes periodos de retorno. Finalmente, los resultados numéricos fueron utilizados para calibrar modelos semianalíticos y paramétricos para su uso en la zona de estudio

Linking plant phenology to conservation biology

Phenology has achieved a prominent position in current scenarios of global change research given its role inmonitoring and predicting the timing of recurrent life cycle events. However, the implications of phenology to environmental conservation and management remain poorly explored. Here,we present the first explicit appraisal of howphenology-amultidisciplinary science encompassing biometeorology, ecology, and evolutionary biology- can make a key contribution to contemporary conservation biology. We focus on shifts in plant phenology induced by global change, their impacts on species diversity and plant-animal interactions in the tropics, and how conservation efforts could be enhanced in relation to plant resource organization. We identify the effects of phenological changes and mismatches in the maintenance and conservation of mutualistic interactions, and examine how phenological research can contribute to evaluate, manage and mitigate the consequences of land-use change and other natural and anthropogenic disturbances, such as fire, exotic and invasive species. Wealso identify cutting-edge tools that can improve the spatial and temporal coverage of phenological monitoring, from satellites to drones and digital cameras. We highlight the role of historical information in recovering long-term phenological time series, and track climate-related shifts in tropical systems. Finally, we propose a set of measures to boost the contribution of phenology to conservation science.Weadvocate the inclusion of phenology into predictive models integrating evolutionary history to identify species groups that are either resilient or sensitive to future climate-change scenarios, and understand how phenological m ismatches can affect community dynamics, ecosystem services, and conservation over time

Mendelian Randomization Analysis of the Relationship Between Native American Ancestry and Gallbladder Cancer Risk

Background A strong association between the proportion of Native American ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest Native American people in Chile. We set out to investigate the causal association between Native American Mapuche ancestry and GBC risk, and the possible mediating effects of gallstone disease and body mass index (BMI) on this association. Methods Markers of Mapuche ancestry were selected based on the informativeness for assignment measure and then used as instrumental variables in two-sample mendelian randomization (MR) analyses and complementary sensitivity analyses. Result We found evidence of a causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% for every 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.6×10-5). Mapuche ancestry was also causally linked to gallstone disease (IVW risk increase of 3.6% per 1% increase in Mapuche proportion, 95% CI 3.1% to 4.0%, p = 1.0×10-59), suggesting a mediating effect of gallstones in the relationship between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative causal effect on BMI (IVW estimate -0.006 kg/m2 per 1% increase in Mapuche proportion, 95% CI -0.009 to -0.003, p = 4.4×10-5). Conclusions The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between Mapuche ancestry and GBC risk previously noted in observational studies appears to be causal, primary and secondary prevention strategies that take into account the individual proportion of Mapuche ancestry could be particularly efficient

Glyoxal tropospheric column retrievals from TROPOMI – multi-satellite intercomparison and ground-based validation

We present the first global glyoxal (CHOCHO) tropospheric column product derived from the TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel-5 Precursor satellite. Atmospheric glyoxal results from the oxidation of other non-methane volatile organic compounds (NMVOCs) and from direct emissions caused by combustion processes. Therefore, this product is a useful indicator of VOC emissions. It is generated with an improved version of the BIRA-IASB scientific retrieval algorithm relying on the differential optical absorption spectroscopy (DOAS) approach. Among the algorithmic updates, the DOAS fit now includes corrections to mitigate the impact of spectral misfits caused by scene brightness inhomogeneity and strong NO2 absorption. The product comes along with a full error characterization, which allows for providing random and systematic error estimates for every observation. Systematic errors are typically in the range of 1 ×10^14–3 ×10^14 molec. cm−2 (∼30 %–70 % in emission regimes) and originate mostly from a priori data uncertainties and spectral interferences with other absorbing species. The latter may be at the origin, at least partly, of an enhanced glyoxal signal over equatorial oceans, and further investigation is needed to mitigate them. Random errors are large ( molec. cm−2) but can be reduced by averaging observations in space and/or time. Benefiting from a high signal-to-noise ratio and a large number of small-size observations, TROPOMI provides glyoxal tropospheric column fields with an unprecedented level of detail. Using the same retrieval algorithmic baseline, glyoxal column data sets are also generated from the Ozone Monitoring Instrument (OMI) on Aura and from the Global Ozone Monitoring Experiment-2 (GOME-2) on board Metop-A and Metop-B. Those four data sets are intercompared over large-scale regions worldwide and show a high level of consistency. The satellite glyoxal columns are also compared to glyoxal columns retrieved from ground-based Multi-AXis DOAS (MAX-DOAS) instruments at nine stations in Asia and Europe. In general, the satellite and MAX-DOAS instruments provide consistent glyoxal columns both in terms of absolute values and variability. Correlation coefficients between TROPOMI and MAX-DOAS glyoxal columns range between 0.61 and 0.87. The correlation is only poorer at one mid-latitude station, where satellite data appear to be biased low during wintertime. The mean absolute glyoxal columns from satellite and MAX-DOAS generally agree well for low/moderate columns with differences of less than 1×10^14 molec. cm−2. A larger bias is identified at two sites where the MAX-DOAS columns are very large. Despite this systematic bias, the consistency of the satellite and MAX-DOAS glyoxal seasonal variability is high