Degradación simulada de la materia seca del matarratón (Gliricidia sepium jacq.) y su relación con la liberación de nitrogeno en un arreglo agroforestal de cultivo en callejones con maíz (Zea Mays)

El artículo esta basado en un trabajo realizado donde se estaban evaluando algunas características de la descomposición de la biomasa del matarratón (Gliricidia sepium Jacq.) en situaciones simuladas de campo, para conocer su importancia como abono orgánico para el suelo y su potencial de permanencia y uso como mejorador de calidad del mismo. Encontramos los materiales y métodos, los resultados y conclusiones de este trabajo.Maíz-Zea may

Riqueza y abundancia relativa de los batoideos de la pesquería artesanal en el archipiélago Espíritu Santo, BCS, México

Background: The Gulf of California possesses a high diversity of marine ichthyofauna while representing one of the main fishing areas in Mexico. The shark and ray fishery constitute an important economic and social importance. Goals: In the present study, the richness and relative abundance was estimated (expressed as CPUE), for 15 batoids species taken by the artisanal fisheries in the southern zone of the Espiritu Santo Island, State of B.C.S. from October 2013 to December 2015. Methods: Batoids were taxonomically identified to species level, measured, sexed and weighed and species richness calculated. Catch as CPUE was standardized to 100 m of gillnet per hour (x100 as a scaling factor) and evaluated among species and at different spatial scales (season, year, season per year and month). Results: A total of 2198 individuals were captured and comprised of four orders, 10 families, 10 genera, and 15 species. The nominal capture effort used was 27560 m of bottom-set gillnet and 1763 h submerged time. Four species, Rostroraja velezi, Pseudobatos glaucostigma, Urobatis maculatus and Mobula mobular, were added to the existing ichthyofauna listing for the Espiritu Santo Island. Additionally, Mobula munkiana and Hypanus dipterurus represented the highest contribution in abundance and weight during the time of this study. The first species is currently protected by national and international laws, whereas the latter is a commercially exploited species. Conclusions: The partial overlap of the highest CPUE values recorded in the warm season, with the fishing ban and the reproductive activity of some species in summer, could contribute as a population recovery effect if the fishing effort after the ban is regulated.Antecedentes: El Golfo de California presenta una alta diversidad de organismos marinos y es una de las principales áreas de pesca en México. La pesquería de tiburones y rayas constituye una importante actividad económica con relevancia social. Objetivo: En el presente estudio se estima la riqueza y abundancia relativa (expresada como CPUE), de 15 especies de batoideos capturados por la pesca artesanal en la zona sur de la Isla Espíritu Santo, B.C.S. desde octubre del 2013 a diciembre de 2015. Métodos: Los ejemplares capturados fueron determinados taxonómicamente al nivel de especie, medidos, sexados y pesados. La riqueza específica correspondió al número total de especies capturadas durante el periodo de estudio. Los datos de CPUE fueron estandarizados a 100 metros de red por hora (x100 como factor de escalamiento) y evaluados entre especies y a diferentes escalas temporales (época, año, época por año y meses). Resultados: Se capturó un total de 2198 individuos, agrupados en cuatro órdenes, 10 familias, 10 géneros y 15 especies. El esfuerzo nominal empleado fue de 27560 metros de red y 1763 horas de remojo. Las especies Rostroraja velezi, Pseudobatos glaucostigma, Urobatis maculatus y Mobula mobular fueron adicionadas a los listados ictiofaunísticos existentes para la Isla Espíritu Santo. Mobula munkiana e Hypanus dipterurus, fueron las especies de batoideos con la mayor contribución en abundancia y peso durante el tiempo de la investigación. La primera está protegida por leyes nacionales e internacionales y la segunda es una especie aprovechada comercialmente. Conclusiones: La superposición parcial de los valores de CPUE más altos registrados en la época cálida, con la veda y la actividad reproductiva de algunas especies en verano, podría contribuir como un efecto de recuperación poblacional si se regula el esfuerzo pesquero posterior a la veda

Smaller limbic structures are associated with greater immunosuppression in over 1000 HIV-infected adults across five continents: Findings from the ENIGMA-HIV Working Group

Background: Human immunodeficiency virus type-1 (HIV) infection can be controlled with combination antiretroviral therapy (cART), but neurocognitive impairment remains common even in chronic and treated HIV-infected (HIV+) cohorts. Identifying the neuroanatomical pathways associated with infection has the potential to delineate novel neuropathological processes underlying persisting deficits, yet individual neuroimaging studies have yielded inconsistent findings. The ENIGMA-HIV Working Group was established to harmonize data from diverse studies to identify the common effects of HIV-infection on brain structure. Methods: Data were pooled from 12 independent neuroHIV studies from Africa, Asia, Australia, Europe, and North America. Volume estimates for eight subcortical brain regions were extracted from T1-weighted MRI from 1,044 HIV+ adults (aged 22-81 years; 72.4% on cART; 70.3% male; 41.6% with detectable viral load (dVL)), to identify associations with plasma markers reflecting current immunosuppression (CD4+ T-cell count) or dVL. Follow-up analyses stratified data by cART status and sex. Bonferroni correction was used to determine statistical significance. Findings: LowercurrentCD4+ count was associated with smaller hippocampal (β= 20.3 mm3 per 100 cells/mm3; p = 0.0001) and thalamic volumes (β= 29.3; p = 0.003); in the subset of participants not on cART, it was associated with smaller putamen volumes (β= 65.1; p = 0.0009). On average, a dVL was associated with smaller hippocampal (Cohen’s d = 0.24; p = 0.0003) and amygdala volumes (d = 0.18; p = 0.0058).Interpretation: In HIV+ individuals across five continents, smaller limbic volumes were consistently associated with current plasma markers. As we assessed cohorts with different inclusion/exclusion criteria and demographic distributions, these deficits may represent a generalizable brain-signature of HIV infection in the cART era. Our findings support the importance of achieving viral suppression and immune restoration for maintaining brain health. Funding: This work was supported, in part, by NIH grant U54 EB020403

Association of Immunosuppression and Viral Load With Subcortical Brain Volume in an International Sample of People Living With HIV

International audienceIMPORTANCE Despite more widely accessible combination antiretroviral therapy (cART), HIV-1 infection remains a global public health challenge. Even in treated patients with chronic HIV infection, neurocognitive impairment often persists, affecting quality of life. Identifying the neuroanatomical pathways associated with infection in vivo may delineate the neuropathologic processes underlying these deficits. However, published neuroimaging findings from relatively small, heterogeneous cohorts are inconsistent, limiting the generalizability of the conclusions drawnto date.OBJECTIVE To examine structural brain associations with the most commonly collected clinicalassessments of HIV burden (CD4+T-cell count and viral load), which are generalizable acrossdemographically and clinically diverse HIV-infected individuals worldwide.DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study established the HIV WorkingGroup within the Enhancing Neuro Imaging Genetics Through Meta Analysis (ENIGMA) consortiumto pool and harmonize data from existing HIV neuroimaging studies. In total, data from 1295HIV-positive adults were contributed from 13 studies across Africa, Asia, Australia, Europe, and NorthAmerica. Regional and whole brain segmentations were extracted from data sets as contributingstudies joined the consortium on a rolling basis from November 1, 2014, to December 31, 2019.MAIN OUTCOMES AND MEASURES Volume estimates for 8 subcortical brain regions wereextracted from T1-weighted magnetic resonance images to identify associations with blood plasmamarkers of current immunosuppression (CD4+T-cell counts) or detectable plasma viral load (dVL) inHIV-positive participants. Post hoc sensitivity analyses stratified data by cART status.RESULTS After quality assurance, data from 1203 HIV-positive individuals (mean [SD] age, 45.7 [11.5]years; 880 [73.2%] male; 897 [74.6%] taking cART) remained. Lower current CD4+cell counts wereassociated with smaller hippocampal (mean [SE] β = 16.66 [4.72] mm3per 100 cells/mm3;P< .001)and thalamic (mean [SE] β = 32.24 [8.96] mm3per 100 cells/mm3;P< .001) volumes and largerventricles (mean [SE] β = −391.50 [122.58] mm3per 100 cells/mm3;P= .001); in participants nottaking cART, however, lowercurrent CD4+cell counts were associated with smaller putamen volumes(mean [SE] β = 57.34 [18.78] mm3per 100 cells/mm3;P= .003). A dVL was associated with smallerhippocampal volumes (d= −0.17;P= .005); in participants taking cART, dVL was also associated withsmaller amygdala volumes (d= −0.23;P= .004

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 11

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 11, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR), Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTAG), Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kleber Ramírez (UPTM), Mérida – Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (C.A.B.B.O.P.P), Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE), Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia - Venezuela, Centro de Investigaciones Internacionales SAS (CIN), Antioquia - Colombia.y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

Degradación de la materia seca del matarratón (Gliricidia sepium Jacq) y su relación con liberación de nitrógeno en arreglos agroforestales

This Project was made in center of Research Palmira, Corpoica (Valle del Cauca-Colombia), to 980 m.a.l.s.; with temperature average of 24oC and 1002 mm precipitation year-l. the type of climate is of Bst to Bh-st. the present experiment determined the simulated degradation of the dry matter of Gliricidia sepium in the soil, in four treatments of alive fences, protein bank, pasture in alleys and cropping in alleys; using nylon bags, during a period of 16 weeks; in predetermined times and it evaluated the characteristics of the biomass and the nitrogen liberation to know its importance as organic installment for the soil and its potential use to improve the quality of soil. The main results were the biomass of Gliricidia presented a rate of mineralization or mean of degradation of 3,4% per week, in addition the nitrogen contribution was evident on the past of Gliricidia to the soil, where it presented a good liberation per week of approximately 5,5% adapted to maintain the presence of this element in the soil, and of fast way since as of the four weeks the greater levels of liberation are reported and environmentally Gliricidia aid to promote the conservation of the natural resources since its interaction with the soil presents positive and important results for a sustainability of organic origin, being avoided this way the use of chemical or toxic elements that leave effects undesirable for environment.Este proyecto se realizo en el Centro de Investigaciones Palmira, Corpoica, Valle del Cauca, a una altura de 980 msnm.; con temperatura promedio de 24oC y con 1002 mm precipitación por año. El tipo de clima es de Bst a Bh-st. El presente experimento determinó la degradación simulada de la materia seca del matarraton Gliricidia sepium en el suelo, en cuatro tratamientos de cercas vivas, banco de proteína, pastura en callejones y cultivo en callejones; usando bolsas de nylon, durante un periodo de 16 semanas; en tiempos predeterminados y evaluó las características de la biomasa y la liberación de nitrógeno para conocer su importancia como abono orgánico para el suelo y su potencial uso para mejorar la calidad del mismo. Los principales resultados fueron; la biomasa del matarraton presento una tasa de mineralización o degradación promedia de 3.4% por semana, además fue evidente el aporte de nitrógeno por parte del matarraton al suelo, donde presento una buena liberación por semana de aproximadamente 5.5% adecuada para mantener la presencia de este elemento en el suelo, y de forma rápida ya que a partir de las cuatro semanas se reportan los mayores niveles de liberación y ambientalmente el matarratón ayuda a promover la conservación de los recursos naturales ya que su interacción con el suelo presenta resultados positivos e importantes para una sostenibilidad de origen orgánico, evitándose de esta manera la utilización de elementos químicos o tóxicos que dejen efectos indeseables para el medio ambiente.

Importance of Weak Trophic Interactions in the Structure of the Food Web in La Paz Bay, Southern Gulf of California: A Topological Approach

Here, we describe the trophic structure of the La Paz Bay, Baja California Sur, Mexico, and evaluate the role of weak trophic interactions in the ecosystem using a suite of topological indices. We used information derived from published and unpublished stomach contents analysis studies from the region to construct an unweighted and directional trophic network (comprising 250 nodes and 1528 associated interactions) to assess the impact of predators in three scenarios. Each scenario simulated the removal of weak interactions corresponding to removal of those nodes with trophic contributions less than 5%, 10%, and 15%. In each removal scenario, the nodes phytoplankton and zooplankton exhibited the greatest betweenness and closeness centrality, suggesting that they are critical groups in the structure of the web, especially in the transference of indirect effects to the largest number of possible nodes in the network. The multiphyletic nature of the phytoplankton and zooplankton, and their ubiquity in diets served to increase their connectivity to all taxonomic groups. We note the presence of numerous weak interactions (67% of taxa have weak trophic interactions) and speculate that this characteristic confers ecological resilience in the Bay of La Paz coastal marine ecosystem