52 research outputs found

    Procedimientos de seguridad para trabajos en altura en minería

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    Algunas de las tareas preliminares para la apertura de una explotación a Cielo Abierto, de un nuevo frente de ésta, de un acceso, así como las actividades de protección, sostenimiento o restauración de taludes finales, requieren la ejecución de trabajos en el medio vertical: desarrollados en laderas o taludes de elevada pendiente, con riesgos de caídas a gran altura y también, en ocasiones, con riesgo de desprendimiento de rocas. En el presente, las empresas que prestan servicios en este campo han adaptado procedimientos del mundo de la escalada o la espeleología, empleando utensilios y elementos de protección de contrastada eficacia pero sin que haya sido reconocida su homologación como tales. El personal, que también procede del ámbito deportivo, presenta excelentes aptitudes para estos trabajos pero no han sido tampoco establecidos los requisitos normativos que garanticen esa aptitud. La diversidad de actividades y las diferentes circunstancias que rodean a éstas convierten a los procedimientos de seguridad para trabajos en altura en una interesante línea de estudio de seguridad. Nosotros queremos con esta comunicación aportar algunos ejemplos con los que resaltar la importancia de eliminar el vacío o ambigüedad normativa en estos trabajos que tienen una repercusión económica elevada.Laboratorio oficial J.M. Madariaga. Universidad Politécnica de Madri

    The effect of a multicomponent intervention on steatosis is partially mediated by the reduction of intermuscular abdominal adipose tissue in children with overweight or obesity: the EFIGRO Project

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    OBJECTIVE: In adults, there is evidence that improvement of metabolic-associated fatty liver disease (MAFLD) depends on the reduction of myosteatosis. In children, in whom the prevalence of MAFLD is alarming, this muscle-liver crosstalk has not been tested. Therefore, we aimed to explore whether the effects of a multicomponent intervention on hepatic fat is mediated by changes in intermuscular abdominal adipose tissue (IMAAT) in children with overweight/obesity. RESEARCH DESIGN AND METHODS: A total of 116 children with overweight/obesity were allocated to a 22-week family-based lifestyle and psychoeducational intervention (control group, n = 57) or the same intervention plus supervised exercise (exercise group, n = 59). Hepatic fat percentage and IMAAT were acquired by MRI at baseline and at the end of the intervention. RESULTS: Changes in IMAAT explained 20.7% of the improvements in hepatic steatosis (P < 0.05). Only children who meaningfully reduced their IMAAT (i.e., responders) had improved hepatic steatosis at the end of the intervention (within-group analysis: responders -20% [P = 0.005] vs. nonresponders -1.5% [P = 0.803]). Between-group analysis showed greater reductions in favor of IMAAT responders compared with nonresponders (18.3% vs. 0.6%, P = 0.018), regardless of overall abdominal fat loss. CONCLUSIONS: The reduction of IMAAT plays a relevant role in the improvement of hepatic steatosis after a multicomponent intervention in children with overweight/obesity. Indeed, only children who achieved a meaningful reduction in IMAAT at the end of the intervention had a reduced percentage of hepatic fat independent of abdominal fat loss. Our findings suggest that abdominal muscle fat infiltration could be a therapeutic target for the treatment of MAFLD in childhood.This project was funded by the Spanish Ministry of Health's Fondos de Investigación Sanitaria del Instituto de Salud Carlos III (PI13/01335), the Spanish Ministry of the Economy Industry and Competitiveness (DEP2016-78377-R), and by European Regional Development Funds (ERDF): Una Manera de Hacer Europa. Support was also provided by the Regional Government of Navarra's Department of Economic Development (0011-1365-2019-000152 & 0011-1365-2020-000243), co-funded by European Regional Development Funds (ERDF 2014-2020 for Navarra). CC-S is supported by the Spanish Ministry of Science and Innovation (FJC2018-037925-I). MM is supported by Junta de Andalucía and European Union (SNGJ Ref-8025). MO is supported by the Spanish Ministry of Economy and Competitiveness (BES-2017-080770). This study was supported by the University of Granada Plan Propio de Investigación 2021 -Excellence actions: Unit of Excellence on Exercise, Nutrition and Health (UCEENS)- and the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades, European Regional Development Funds (ref. SOMM17/6107/UGR)

    Monte carlo clinical dosimetry

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    The choice of the most appropriate strategy for radiotherapy treatment is mainly based on the use of a planning system. With the introduction of new techniques (conformal and/or small fields, asymmetrical and non coplanar beams, true 3D calculation, IMRT) the trustworthiness of the algorithms used is questioned. An alternative verification procedure has become increasingly more necessary to warranty treatment delivery.The reliability of the Monte Carlo method is generally acknowledged. However, its clinical use has not been practical due to the high CPU time required. During the last few years our objective has decreased CPU time by means of a new process distribution technique. This reduction has made it feasible, not only to apply physical dosimetry under special conditions, but also to use it in numerous clinical cases employing photon and electron conformal fields, in radiosurgery, and IMRT.The procedure carried out is presented. Furthermore, conventional Treatment Planning System calculations are compared with the Monte Carlo simulations

    Differences in areal bone mineral density between metabolically healthy and unhealthy overweight/obese children: the role of physical activity and cardiorespiratory fitness

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    “This manuscript was published by SPRINGERNATURE in Pediatric Research on June 2020, available at: doi: 10.1038/s41390-019-0708-x.”OBJECTIVES: To examine whether areal bone mineral density (aBMD) differs between metabolically healthy (MHO) and unhealthy (MUO) overweight/obese children and to examine the role of moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF) in this association. METHODS: A cross-sectional study was developed in 188 overweight/obese children (10.4 ± 1.2 years) from the ActiveBrains and EFIGRO studies. Participants were classified as MHO or MUO based on Jolliffe and Janssen’s metabolic syndrome cut-off points for triglycerides, glucose, high-density cholesterol and blood pressure. MVPA and CRF were assessed by accelerometry and the 20-m shuttle run test, respectively. Body composition was measured by dual-energy X-ray absorptiometry. RESULTS: In model 1 (adjusted for sex, years from peak high velocity, stature and lean mass), MHO children had significantly higher aBMD in total body less head (Cohen’s d effect size, ES = 0.34), trunk (ES = 0.43) and pelvis (ES = 0.33) than MUO children. These differences were attenuated once MVPA was added to model 1 (model 2), and most of them disappeared once CRF was added to the model 1 (model 3). CONCLUSIONS: This novel research shows that MHO children have greater aBMD than their MUO peers. Furthermore, both MVPA and more importantly CRF seem to partially explain these findings.The authors thank the staff and participants of the ActiveBrains and EFIGRO studies for their important contributions. This study has been partially funded by the University of Granada, UGR Research and Knowledge Transfer Fund (PPIT) 2016, Excellence Actions Programme: Units of Scientific Excellence; Scientific Unit of Excellence on Exercise and Health (UCEES), and by the Regional Government of Andalusia, Regional Ministry of Economy, Knowledge, Enterprises and University and European Regional Development Fund (ERDF), ref. SOMM17/6107/UGR. The ActiveBrains study was funded by the Spanish Ministry of Economy and Competitiveness (Reference DEP2013-47540, DEP2016-79512-R, and DEP2017-91544-EXP). The EFIGRO study was funded by the Spanish Ministry of Health, “Fondo de Investigación Sanitaria del Instituto de Salud Carlos III” (PI13/01335), “Fondos Estructurales de la Unión Europea (FEDER), Una manera de hacer Europa,” and by the University of the Basque Country (GIU14/21). L.G.-M. is supported by “La Caixa” Foundation within the Junior Leader fellowship programme (ID 100010434); M.M. is supported by the Spanish Ministry of Education, Culture and Sport (FPU14/03329) and EST17/00210; L.A. is supported by the Education Department of the Government of the Basque Country (PRE_2016_1_0057, PRE_2017_2_0224 and PRE_2018_2_0057); J.M.-G. and J.H.M. are supported by the Spanish Ministry of Education, Culture and Sport (FPU14/06837 and FPU15/02645, respectively)

    Rehabilitación de una presa de residuos mineros mediante la aplicación de lodo de mármol y purín de cerdo para el desarrollo de una fitoestabilización asistida

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    Abandoned tailings ponds produce environmental and human health hazards due to the transfer of heavy metals through wind and water erosion or leaching. To reduce these hazards, a reclamation strategy has been developed on a tailings pond based on aided phytostabilization. In 2011 marble mud and pig slurry were applied to the surface of a tailings pond and in the spring of 2012 thirteen native vegetal species were introduced. The evolution of different soil properties and the bio-available fraction of the heavy metals Cd, Pb and Zn were monitored for two years (2012-2013). The results showed that the pH, aggregate stability, organic carbon, total nitrogen and cation exchange capacity increased after the application of the amendments and the growth of vegetation, whilst the bio-available fraction of the heavy metals drastically decreased (90-99%). Thus, the strategy followed proved to be positive for reducing the availability of heavy metals and improving soil quality and fertility. These results are promising in areas with extractive activity of carbonated materials, since the generated waste can be used for the reclamation of soils affected by heavy metals, transforming a residual material into a useful by-product.Este trabajo ha sido cofinanciado por el proyecto de la Unión Europea LIFE+ MIPOLARE (LIFE09 ENV/ES/000439)

    Hybrid passive cooling and heating system for Mediterranean greenhouses. Microclimate and sweet pepper crop response

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    The microclimate of low-tech, unheated greenhouses in Mediterranean areas, associated with the local outdoor climate, is often outside the optimal range for most horticultural crops during both the warm and cold growing season. The use of a new hybrid system of passive cooling (evaporative screens) and heating (water-filled sleeves), in combination with an internal movable shading/thermal screen, was evaluated on a representative summer transplanted sweet pepper crop grown in perlite growing bags. The experiment was carried out in two identical greenhouses at the IFAPA La Mojonera research center in Almeria (SE Spain): one greenhouse with the hybrid passive system of cooling and heating, in combination with a shading/thermal screen, and another (reference greenhouse) using common local greenhouse climate management practices. Evaporative screens, in combination with a movable shading screen, improved the greenhouse climate, in particular the air vapour pressure deficit, and increased the leaf area index in the early stages of the crop, which, in turn, increased the early production of leaf and shoot dry matter and marketable fruit, compared to the reference greenhouse crop. In addition, the combined use of water-filled sleeves and thermal screen during the cold growth period increased greenhouse air temperatures, especially at night, and substrate temperatures. Overall, by improving the greenhouse microclimate during the warm and cold growth periods, the hybrid passive cooling/heating system, in combination with the shading/thermal screen, increased the marketable yield of a summer transplanted sweet pepper crop by 25 %, reduced the irrigation water supply by 8 %, and improved the irrigation water use efficiency by 20 % (including the potential water used to humidify the evaporative screens)

    Prediction of poor outcome in clostridioides difficile infection: A multicentre external validation of the toxin B amplification cycle

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    Producción CientíficaClassification of patients according to their risk of poor outcomes in Clostridioides difficile infection (CDI) would enable implementation of costly new treatment options in a subset of patients at higher risk of poor outcome. In a previous study, we found that low toxin B amplification cycle thresholds (Ct) were independently associated with poor outcome CDI. Our objective was to perform a multicentre external validation of a PCR-toxin B Ct as a marker of poor outcome CDI. We carried out a multicentre study (14 hospitals) in which the characteristics and outcome of patients with CDI were evaluated. A subanalysis of the results of the amplification curve of real-time PCR gene toxin B (XpertTM C. difficile) was performed. A total of 223 patients were included. The median age was 73.0 years, 50.2% were female, and the median Charlson index was 3.0. The comparison of poor outcome and non–poor outcome CDI episodes revealed, respectively, the following results: median age (years), 77.0 vs 72.0 (p = 0.009); patients from nursing homes, 24.4% vs 10.8% (p = 0.039); median leukocytes (cells/μl), 10,740.0 vs 8795.0 (p = 0.026); and median PCR-toxin B Ct, 23.3 vs 25.4 (p = 0.004). Multivariate analysis showed that a PCR-toxin B Ct cut-off <23.5 was significantly and independently associated with poor outcome CDI (p = 0.002; OR, 3.371; 95%CI, 1.565–7.264). This variable correctly classified 68.5% of patients. The use of this microbiological marker could facilitate early selection of patients who are at higher risk of poor outcome and are more likely to benefit from newer and more costly therapeutic options

    Sistemas pasivos de calefacción en invernaderos mediterráneos.

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    El libro es un compendio de las técnicas de calefacción pasiva de interés para los invernaderos de clima mediterráneo. Se analizan seis técnicas: materiales de cubierta, acolchados, dobles techos, pantallas térmicas, mangas de agua y “tunelillos”, nombre popular con el que se conoce el pequeño túnel que cubre las hileras de plantas en las primeras fases de cultivo

    Teoría económica aplicada

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    El objetivo de este libro es lograr un mayor acercamiento entre los trabajos meramente cuantitativos y los puramente teóricos. Así, los quince trabajos presentados desarrollan modelos teóricos para representar la situación a estudiar de la realidad mexicana y son complementados con información cuantitativa. Se incluyen diversos temas que van desde el análisis de la conducta de los delincuentes y el entorno en que actúan, hasta el análisis de legislaciones que rigen diversas actividades y mercados. Se habla de seguridad social, impuestos, banca de desarrollo, sector externo, servicios públicos como agua, educación, trabajo infantil, costo compartido, discriminación de precios, reglas de reparto y seguros de vida. La intención es invitar al lector a conocer la relevancia de la teoría económica y sus modelos cuantitativos en las decisiones de la vida real.Enrique R. Casares; Leobardo Plata, compiladore
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