Índices para la evaluación de un seguidor solar

The usage of solar trackers in solar energy technologies represents an alternative to increase the capture of solar radiation. However, the costs involved convert it into a prohibitive technology, having indexes and procedures that allow for its evaluation and determination of the viability of its use is of vital importance at the time of deciding its implementation and so to form the objective of this study. In the investigation carried out, the indexes of average gain, comparative efficiency and profitability are introduced and a procedure for the evaluation is developed, as a contribution to the decision-making process as to whether or not to use a solar tracker. It is confirmed that the use of trackers is completely viable when used with higher power technologies. Furthermore, it is shown that theoretically, the average gain index is higher than the values currently registered in scientific literature. Such factors support the possibility of designing and developing solar trackers with a higher gain, lower production costs and lower consumption indexes, as a way for their mass use in low power photovoltaic generators.El uso de los seguidores solares como tecnología de aprovechamiento de energía solar representa una alternativa para incrementar la captación de radiación solar. Sin embargo, sus costos lo convierten en una tecnología prohibitiva, por lo que disponer de índices y procedimientos que permitan su evaluación para determinar la viabilidad de uso es una herramienta de extrema importancia a la hora de decidir sobre su utilización y constituye el objetivo de este trabajo. Con la investigación realizada se introducen los índices de ganancia media, eficiencia comparativa y de utilidad y se desarrolla un procedimiento de evaluación, como contribución a la toma de decisiones sobre el uso o no de un seguidor solar. Se corrobora que su uso es totalmente viable mientras mayor es la potencia de las tecnologías en las cuales se utiliza. Además, se muestra que teóricamente el índice medio de ganancia es mayor que los valores registrados actualmente en la literatura científica. Tales elementos apoyan la posibilidad de diseñar y desarrollar seguidores solares con mayor ganancia, menores costos de fabricación y menores índices de consumo, como vía para su utilización masiva en generadores fotovoltaicos de baja potencia

Prevalence of infection with high-risk human papillomavirus in women in Colombia

AbstractThe prevalence of human papillomavirus (HPV) infections in 2109 females inhabiting five cities of Colombia was determined. Of the 49.2% with an HPV infection, 59.8% were infected with more than one viral type. Species 7 (of the the genus Alphapapillomavirus) was associated with multiple infections. Analysis of the socio-demographic data revealed a statistically significant protective effect associated with the status of civil union (civil recognition of cohabitation without marriage), and indigenous ethnicity proved to be a risk factor for HPV infection. This is the first study comparing HPV infection among women from geographical regions of Colombia with different socio-cultural structures

Effects of leucine-enriched whey protein supplementation on physical function in post-hospitalized older adults participating in 12-weeks of resistance training program: a randomized controlled trial

Age-related strength and muscle mass loss is further increased after acute periods of inactivity. To avoid this, resistance training has been proposed as an effective countermeasure, but the additional effect of a protein supplement is not so clear. The aim of this study was to examine the effect of a whey protein supplement enriched with leucine after resistance training on muscle mass and strength gains in a post-hospitalized elderly population. A total of 28 participants were included and allocated to either protein supplementation or placebo supplementation following resistance training for 12 weeks (2 days/week). Physical function (lower and upper body strength, aerobic capacity and the Short Physical Performance Battery (SPPB) test), mini nutritional assessment (MNA) and body composition (Dual X-ray Absorptiometry) were assessed at baseline and after 12 weeks of resistance training. Both groups showed improvements in physical function after the intervention (p 0.05). Muscle mass did not improve after resistance training in either group (p > 0.05). In conclusion, 12 weeks of resistance training are enough to improve physical function in a post-hospitalized elderly population with no further benefits for the protein-supplemented group.This study was supported by the Basque Government (2016111138), and the European Regional Development Funds (ERDF), the University of Granada Plan Propio de Investigación 2016 (Excellence Actions: Unit of Excellence on Exercise and Health [UCEES]) and the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades (ERDF: ref. SOMM17/6107/UGR). MA was supported by a grant from the University of the Basque Country (PIF17/186), IE by a grant from the University of the Basque Country in collaboration with the University of Bordeaux (Université of Bordeaux (UBX)) (PIFBUR16/07) and JRR by grants from the Spanish Ministry of Economy and Competitiveness (RYC 2010-05957; RYC-2011-09011 and BES-2014-068829).This work was also supported by grants from the Public University of Navarra, 'Plan de Promoción de Grupos de Investigación (2019)'

High-resolution seasonal and decadal inventory of anthropogenic gas-phase and particle emissions for Argentina

This work presents the integration of a gas-phase and particulate atmospheric emission inventory (AEI) for Argentina in high spatial resolution (0.025×0.025; approx. 2.5km×2.5 km) considering monthly variability from 1995 to 2020. The new inventory, called GEAA-AEIv3.0M, includes the following activities: Energy production, fugitive emissions from oil and gas production, industrial fuel consumption and production, transport (road, maritime, and air), agriculture, livestock production, manufacturing, residential, commercial, and biomass and agricultural waste burning. The following species, grouped by atmospheric reactivity, are considered: (i) greenhouse gases (GHGs)-CO2, CH4, and N2O; (ii) ozone precursors-CO, NOx (NO+NO2), and non-methane volatile organic compounds (NMVOCs); (iii) acidifying gases-NH3 and SO2; and (iv) particulate matter (PM)-PM10, PM2.5, total suspended particles (TSPs), and black carbon (BC). The main objective of the GEAA-AEIv3.0M high-resolution emission inventory is to provide temporally resolved emission maps to support air quality and climate modeling oriented to evaluate pollutant mitigation strategies by local governments. This is of major concern, especially in countries where air quality monitoring networks are scarce, and the development of regional and seasonal emissions inventories would result in remarkable improvements in the time and space chemical prediction achieved by air quality models. Despite distinguishing among different sectoral and activity databases as well as introducing a novel spatial distribution approach based on census radii, our high-resolution GEAA-AEIv3.0M shows equivalent national-wide total emissions compared to the Third National Communication of Argentina (TNCA), which compiles annual GHG emissions from 1990 through 2014 (agreement within ±7.5%). However, the GEAA-AEIv3.0M includes acidifying gases and PM species not considered in TNCA. Temporal comparisons were also performed against two international databases: Community Emissions Data System (CEDS) and EDGAR HTAPv5.0 for several pollutants; for EDGAR it also includes a spatial comparison. The agreement was acceptable within less than 30% for most of the pollutants and activities, although a >90% discrepancy was obtained for methane from fuel production and fugitive emissions and >120% for biomass burning. Finally, the updated seasonal series clearly showed the pollution reduction due to the COVID-19 lockdown during the first quarter of year 2020 with respect to same months in previous years. Through an open-access data repository, we present the GEAA-AEIv3.0M inventory as the largest and more detailed spatial resolution dataset for the Argentine Republic, which includes monthly gridded emissions for 12 species and 15 stors between 1995 and 2020.Fil: Puliafito, Salvador Enrique. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bolanõ Ortiz, Tomás R.. Universidad Tecnológica Nacional; Argentina. Universidad Técnica Federico Santa María; ChileFil: Fernandez, Rafael Pedro. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Berná, Lucas L.. Universidad Tecnológica Nacional; Argentina. Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica; ArgentinaFil: Pascual Flores, Romina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Urquiza, Josefina. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Lopez Noreña, Ana Isabel. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Tames, María Florencia. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin

Análise comparativa de métodos de genotipagem para avaliação da Síndrome da Musculatura Dupla em bovinos de corte.

Em diversas raças bovinas têm sido observadas mutações no gene que codifica a proteína miostatina (GDF-8), determinando a síndrome da hipertrofia muscular. Este fenótipo confere ao animal limitações fisiológicas e reprodutivas. Entretanto, com relação a aspectos econômicos, as carcaças destes animais são consideradas superiores, resultando em maior produção de carne, maior proporção de cortes nobres e carne mais macia e magra. Neste contexto, objetivou-se testar três metodologias de genotipagem e comparar qual a melhor em relação custo/benefício, com o intuito de avaliar a mutação nt821 em bovinos de corte. Foi extraído DNA genômico de amostras biológicas de 17 animais da raça Senepol, sendo sete com o fenótipo da musculatura dupla e dez sem o fenótipo. As amostras de DNA foram quantificadas por espectrofotometria e, posteriormente, foram submetidas à reação em cadeia da polimerase (PCR)

Widespread forest vertebrate extinctions induced by a mega hydroelectric dam in lowland Amazonia

Mega hydropower projects in tropical forests pose a major emergent threat to terrestrial and freshwater biodiversity worldwide. Despite the unprecedented number of existing, underconstruction and planned hydroelectric dams in lowland tropical forests, long-term effects on biodiversity have yet to be evaluated. We examine how medium and large-bodied assemblages of terrestrial and arboreal vertebrates (including 35 mammal, bird and tortoise species) responded to the drastic 26-year post-isolation history of archipelagic alteration in landscape structure and habitat quality in a major hydroelectric reservoir of Central Amazonia. The Balbina Hydroelectric Dam inundated 3,129 km2 of primary forests, simultaneously isolating 3,546 land-bridge islands. We conducted intensive biodiversity surveys at 37 of those islands and three adjacent continuous forests using a combination of four survey techniques, and detected strong forest habitat area effects in explaining patterns of vertebrate extinction. Beyond clear area effects, edge-mediated surface fire disturbance was the most important additional driver of species loss, particularly in islands smaller than 10 ha. Based on species-area models, we predict that only 0.7% of all islands now harbor a species-rich vertebrate assemblage consisting of ≥80% of all species. We highlight the colossal erosion in vertebrate diversity driven by a man-made dam and show that the biodiversity impacts of mega dams in lowland tropical forest regions have been severely overlooked. The geopolitical strategy to deploy many more large hydropower infrastructure projects in regions like lowland Amazonia should be urgently reassessed, and we strongly advise that long-term biodiversity impacts should be explicitly included in pre-approval environmental impact assessments

Activation-induced cytidine deaminase targets SUV4-20-mediated histone H4K20 trimethylation to class-switch recombination sites

Activation-induced cytidine deaminase (AID) triggers antibody diversification in B cells by catalysing deamination and subsequently mutating immunoglobulin (Ig) genes. Association of AID with RNA Pol II and occurrence of epigenetic changes during Ig gene diversification suggest participation of AID in epigenetic regulation. AID is mutated in hyper-IgM type 2 (HIGM2) syndrome. Here, we investigated the potential role of AID in the acquisition of epigenetic changes. We discovered that AID binding to the IgH locus promotes an increase in H4K20me3. In 293F cells, we demonstrate interaction between co-transfected AID and the three SUV4-20 histone H4K20 methyltransferases, and that SUV4-20H1.2, bound to the IgH switch (S) mu site, is replaced by SUV4-20H2 upon AID binding. Analysis of HIGM2 mutants shows that the AID truncated form W68X is impaired to interact with SUV4-20H1.2 and SUV4-20H2 and is unable to bind and target H4K20me3 to the Smu site. We finally show in mouse primary B cells undergoing class-switch recombination (CSR) that AID deficiency associates with decreased H4K20me3 levels at the Smu site. Our results provide a novel link between SUV4-20 enzymes and CSR and offer a new aspect of the interplay between AID and histone modifications in setting the epigenetic status of CSR sites