220 research outputs found

    Nature-based solutions for flood mitigation and soil conservation in a steep-slope olive-orchard catchment (Arquillos, Spain)

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    The frequency and magnitude of flash floods in the olive orchards of southern Spain have increased because of climate change and unsustainable olive-growing techniques. Affected surfaces occupy >85% of the rural regions of the Upper Guadalquivir Basin. Dangerous geomorphic processes record the increase of runoff, soil loss and streamflow through time. We report on ripple/dune growth over a plane bed on overland flows, deep incision of ephemeral gullies in olive groves and rock-bed erosion in streams, showing an extraordinary sediment transport capacity of sub-daily pluvial floods. We develop a novel method to design optimal solutions for natural flood management and erosion risk mitigation. We adopt physical-based equations and build a whole-system model that accurately reproduces the named processes. The approach yields the optimal targeted locations of nature-based solutions (NbSs) for active flow-control by choosing the physical-model parameters that minimise the peak discharge and the erosion-prone area, maximising the soil infiltration capacity. The sub-metric spatial resolution used to resolve microtopographic features of terrains/NbS yields a computational mesh with millions of cells, requiring a Graphics Processing Unit (GPU) to run massive numerical simulations. Our study could contribute to developing principles and standards for agricultural-management initiatives using NbSs in Mediterranean olive and vineyard orchards.This work was funded by: “Programa Operativo FEDER 2014-2020” and “Consejería de Economía y Conocimiento de la Junta de Andalucía” grant number 138096; the European Union NextGenerationEU/PRTR and MCIN/AEI/10.13039/501100011033 grant number TED2021-129910B-I00

    Technological advances to rescue temporary and ephemeral wetlands: reducing their vulnerability, making them visible

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    Mediterranean temporary ponds are a priority habitat according to the Natura 2000 network of the European Union, and complete inventories of these ecosystems are therefore needed. Their small size, short hydroperiod, or severe disturbance make these ponds undetectable by most remote sensing systems. Here we show, for the first time, that the distributed hydrologic model IBER+ detects ephemeral and even extinct wetlands by fully exploiting the available digital elevation model and resolving many microtopographic features at drainage basin scales of about 1000 km2. This paper aims to implement a methodology for siting flood-prone areas that can potentially host a temporary wetland, validating the results with historical orthophotos and existing wetlands inventories. Our model succeeds in dryland endorheic catchments of the Upper Guadalquivir Basin: it has detected 89% of the previously catalogued wetlands and found four new unknown wetlands. In addition, we have found that 24% of the detected wetlands have disappeared because of global change. Subsequently, environmental managers could use the proposed methodology to locate wetlands quickly and cheaply. Finding wetlands would help monitor their conservation and restore them if needed.This work was funded by: “Programa Operativo FEDER 2014–2020” and “Consejería de Economía y Conocimiento de la Junta de Andalucía” grant number 138096; the European Union NextGenerationEU/PRTR and MCIN/AEI/10.13039/501100011033 grant number TED2021-129910BI00

    Análise do crescimento e desempenho morfofisiológico de três cultivares de quinoa colombiana cultivadas em casa de vegetação

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    Quinoa (Amaranthaceae) é um pseudo-cereal nativo produzido em toda a zona sul-americana, onde é utilizada como alimento e alternativa promissora para o cultivo em áreas edafoclimáticas afetadas por fatores antrópicos e naturais. Entre os principais problemas que afetam a produção agrícola, inclui-se aqueles relacionados ao crescimento, desenvolvimento e produção, gerados por limitações de adaptabilidade de novas cultivares em áreas específicas. Por este motivo, esta pesquisa teve como objetivo analisar o crescimento e o comportamento morfológico das cultivares de quinoa Blanca Soracá (BS), Blanca Jericó (BT) e Tunkahuan (T). O estudo foi realizado na estufa da Faculdade de Ciências Agrárias da Universidade de Cauca (Colômbia) a 1880 m.a.n.m A análise permitiu reconhecer que as três cultivares de quinoa apresentam diferentes épocas de desenvolvimento fenológico até a colheita (138,25 ± 2,3 e 161 ± 1,1 dias). O número de folhas, a altura das plantas e o número de ramos mostram ajuste às equações de regressão sigmoidal (R2 0,99 – 0,98) para as cultivares BJ e T, enquanto o teor de clorofila total foi ajustado para comportamento cúbica (R2 0,90 – 0,89). As cultivares de quinoa expressam comportamentos produtivos associados a ciclos precoces e tardios, mostrando diferenças na produção e peso das sementes

    Inducing a topological transition in graphene nanoribbon superlattices by external strain

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    Armchair graphene nanoribbons, when forming a superlattice, can be classified into different topological phases, with or without edge states. By means of tight-binding and classical molecular dynamics (MD) simulations, we studied the electronic and mechanical properties of some of these superlattices. MD shows that fracture in modulated superlattices is brittle, as for unmodulated ribbons, and occurs at the thinner regions, with staggered superlattices achieving a larger fracture strain than inline superlattices. We found a general mechanism to induce a topological transition with strain, related to the electronic properties of each segment of the superlattice, and by studying the sublattice polarization we were able to characterize the transition and the response of these states to the strain. For the cases studied in detail here, the topological transition occurred at ∼3-5% strain, well below the fracture strain. The topological states of the superlattice - if present - are robust to strain even close to fracture. The topological transition was characterized by means of the sublattice polarization of the states.Fil: Flores Gutierréz, Esteban. Universidad de Chile; ChileFil: Mella, José D.. Universidad de Chile; ChileFil: Aparicio, Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad de Mendoza. Facultad de Ingenieria; ArgentinaFil: Gonzalez, Rafael I.. Universidad Mayor; Chile. Centro para el Desarrollo de la Nanociencia y la Nanotecnología; ChileFil: Parra, C.. Universidad Mayor; ChileFil: Bringa, Eduardo Marcial. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad de Mendoza. Facultad de Ingenieria; Argentina. Universidad Mayor; ChileFil: Munoz, Francisco. Centro para el Desarrollo de la Nanociencia y la Nanotecnología; Chile. Universidad de Chile; Chil

    Épocas de nacimiento basadas en un índice climático para el ajuste de modelos estadísticos para peso vivo de ganado bovino en México

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    Artículo de investigación científica publicado en revista indizada.El objetivo fue comparar los efectos de una metodología para la clasificación de épocas climáticas, que tradicionalmente son utilizadas para establecer épocas de nacimiento (EN) en estudios y experimentos estadísticos. Esta metodología se basa en un índice de aridez (IA) para clasificar las EN utilizando información meteorológica histórica. Se trabajó una base de datos con un pedigrí de 7,460 animales, se ajustaron dos modelos para peso al nacimiento y peso al destete en bovinos Charolais manejados en pastoreo extensivo. Los modelos incluyeron el efecto fijo de grupo contemporáneo (GC= subclase de hato, sexo, año y EN) y edad de la madre. Los mismos modelos se compararon utilizando una clasificación tradicional de estaciones del año para clasificar las EN. Al estimar los componentes de varianza y valores genéticos (DEP) con sus exactitudes, los modelos fueron diferentes de acuerdo a la prueba de razón de verosimilitudes (P<0.01). El número de GC se redujo en 25 % para la EN basada en el IA, con GC con mayor número de individuos. El principal efecto observado en los modelos analizados fue el cambio en la jerarquización de las DEP para ambas características. Este método de clasificación de épocas de nacimiento, puede ayudar a mejorar el ajuste de modelos estadísticos en los sistemas ganaderos manejados en pastoreo extensivo

    Runalytics, 3D gait analysis system

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    [EN] Nowadays running is one of the most popular sports, which has fostered the development of its technology, both in the materials used and in their selection. Footwear is the basic component for the practice of running, as well as the most important one due to its ability to adapt to each runner through the proper choice. Such was the case that nowadays there is a lack of substance in the methods used for counseling. Runalytics is created with the idea of analyzing in detail the biomechanical characteristics each runner, based on an exhaustive research study to facilitate the choice of footwear that best suits the needs of each runner.[ES] Actualmente el running es uno de los deportes más practicados, lo que ha fomentado el desarrollo de su tecnología, tanto en los materiales utilizados como en su elección. El calzado es el componente básico para la práctica de la carrera, siendo además el más importante por su capacidad de adaptación a cada corredor mediante una correcta elección del mismo. Tanto es así que actualmente se plantea una falta de métodos precisos y robustos para el asesoramiento en la selección del mejor calzado de running para un usuario específico. Runalytics nace con la idea de analizar al detalle las características biomecánicas de cada corredor a partir de criterios validados en un exhaustivo estudio de investigación con la finalidad de facilitar la elección del calzado que mejor se adapte a las necesidades de cada deportista.Medina Ripoll, E.; Parrilla Bernabé, E.; Romero Olucha, E.; Montero Vilela, J.; Parra Gonzalez, F.; Gonzalez Garcia, JC.; Gil Mora, S.... (2013). Runalytics, sistema de análisis 3D de la pisada. Revista de biomecánica. 60:21-24. http://hdl.handle.net/10251/38696S21246

    Vibrational properties of CdGa2S4 at high pressure

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    [EN] Raman scattering measurements have been performed in cadmium digallium sulphide (CdGa2S4) with defect chalcopyrite structure up to 25 GPa in order to study its pressure-induced phase transitions. These measurements have been complemented and compared with latticedynamics ab initio calculations including the TO-LO splitting at high pressures in order to provide a better assignment of experimental Raman modes. In addition, experimental and theoretical Gruneisen parameters have been reported in order to calculate the molar heat capacity and thermal expansion coefficient of CdGa2S4. Our measurements provide evidence that CdGa2S4 undergoes an irreversible phase transition above 15 GPa to a Raman-inactive phase, likely with a disordered rock salt structure. Moreover, the Raman spectrum observed on downstroke from 25 GPa to 2 GPa has been attributed to a new phase, tentatively identified as a disordered zinc blende structure, that undergoes a reversible phase transition to the Raman-inactive phase above 10 GPa. Published under license by AIP Publishing.The authors thank the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) under Grant Nos. MAT2016-75586-C4-2/3-P and MAT2015-71070-REDC (MALTA Consolider) and the Generalitat Valenciana under Project No. PROMETEO/2018/123-EFIMAT. E. P.-G., A. M., and P. R.-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster.Gallego-Parra, S.; Gomis, O.; Vilaplana Cerda, RI.; Ortiz, H.; Perez-Gonzalez, E.; Luna Molina, R.; Rodríguez-Hernández, P.... (2019). Vibrational properties of CdGa2S4 at high pressure. Journal of Applied Physics. 125(11):1-12. https://doi.org/10.1063/1.5080503S11212511Gomis, O., Santamaría-Pérez, D., Vilaplana, R., Luna, R., Sans, J. A., Manjón, F. J., … Ursaki, V. V. (2014). Structural and elastic properties of defect chalcopyrite HgGa2S4 under high pressure. Journal of Alloys and Compounds, 583, 70-78. doi:10.1016/j.jallcom.2013.08.123Cohen, M. L. (1985). Calculation of bulk moduli of diamond and zinc-blende solids. Physical Review B, 32(12), 7988-7991. doi:10.1103/physrevb.32.7988Kim, J. W., & Kim, Y. J. (2007). Optical Properties of Eu Doped M-Ga2S4 (M:Zn, Ca, Sr) Phosphors for White Light Emitting Diodes. Journal of Nanoscience and Nanotechnology, 7(11), 4065-4068. doi:10.1166/jnn.2007.066Yu, R., Noh, H. M., Moon, B. K., Choi, B. C., Jeong, J. H., Jang, K., … Jang, J. K. (2013). Photoluminescence properties of a new red-emitting Mn-activated ZnGa2S4 phosphor. 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A., … Burke, K. (2008). Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces. Physical Review Letters, 100(13). doi:10.1103/physrevlett.100.136406Sans, J. Á., Santamaría-Pérez, D., Popescu, C., Gomis, O., Manjón, F. J., Vilaplana, R., … Tiginyanu, I. M. (2014). Structural and Vibrational Properties of CdAl2S4under High Pressure: Experimental and Theoretical Approach. The Journal of Physical Chemistry C, 118(28), 15363-15374. doi:10.1021/jp5037926Lottici, P. P., & Razzetti, C. (1984). Raman scattering in mixed defect chalcopyrite crystals. Journal of Molecular Structure, 115, 133-136. doi:10.1016/0022-2860(84)80032-0Kerimova, T. G., Abdullaev, N. A., Mamedova, I. A., Badalova, Z. I., Guliev, R. A., Paucar, R., … Mamedov, N. T. (2013). Optical phonons in CdGa2S4x Se4(1 − x) alloys. Semiconductors, 47(6), 761-766. doi:10.1134/s1063782613060110Tiginyanu, I. M., Lottici, P. P., Razzetti, C., & Gennari, S. (1993). Effects of the Cations on the Raman Spectra of Sulphur Defect Chalcopyrites. Japanese Journal of Applied Physics, 32(S3), 561. doi:10.7567/jjaps.32s3.561Kerimova, T. G., Mamedova, I. A., Abdullayev, N. A., Asadullayeva, S. Q., & Badalova, Z. I. (2014). Raman scattering in ZnGa2Se4 single crystals. Semiconductors, 48(7), 868-871. doi:10.1134/s1063782614070112Razzetti, C., & Lottici, P. P. (1993). Raman Scattering in Defective AIIB2IIIX4VICompounds and Alloys. Japanese Journal of Applied Physics, 32(S3), 431. doi:10.7567/jjaps.32s3.431Syrbu, N. N., Nemerenco, L. L., & Cojocaru, O. (2002). Vibrational and Polariton Spectra of CdGa2S4 and CdAl2S4 Crystals. Crystal Research and Technology, 37(1), 101-110. doi:10.1002/1521-4079(200202)37:13.0.co;2-dGomis, O., Vilaplana, R., Manjón, F. J., Santamaría-Pérez, D., Errandonea, D., Pérez-González, E., … Ursaki, V. V. (2013). High-pressure study of the structural and elastic properties of defect-chalcopyrite HgGa2Se4. 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    Produção de carne nos trópicos secos de Tamaulipas, México: cruzamento de Bos taurus e Bos indicus

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    The objective of this study was evaluated the productive performance in Charolais (CH), Simmental (SM) and Braunvieh (BR) sires and Zebu, (ZE), Suiss (SU) x ZE and CH x ZE dams, among birth and weaning calves weights. The environment is dry tropical with summer rains. The livestock grassing in a introducing grasses Star grass (Cynodon nlemfuensis) y Guinea (Panicum maximun). The reproduction was artificial insemination with CH, SM and BR semen and natural insemination with CH sires after insemination. The calves were identificated at birth with the mother number and were weighted in the first 24 ours. The data were analyzed with minimum squares method to determinate, season (SE), calf sex (SX) and dam age (DE). The average for birth weight (BW) was 34.6 kg and only the SE were statistical significant (P &lt; 0.05) for this characteristic. For weaning weight (WW) the mean was 165.7 kg and SE and DE and were statistical significant (P &lt; 0.05). The conclusion is that the environmental effects in this study was more important than genetics effects both BW and WW variables.El objetivo del presente estudio fue evaluar la productividad de toros Charoláis (CH), Simmental (SM) y Pardo Suizo (PS) con vacas Cebú (CE), PS x CE y CH x CE a través del peso al nacimiento y al destete de los becerros. El rancho contaba con praderas de Estrella de África (Cynodon nlemfuensis) y Guinea (Panicum maximun), utilizadas con pastoreo rotacional. La reproducción de las vacas fue a través de inseminación artificial con semen de SM, CH y PS y fueron repasadas por toros CH. Los becerros fueron tatuados en la oreja con el número de la madre y se pesaron en las primeras 24 h después del nacimiento. Los datos fueron analizados por el método de cuadrados mínimos para determinar los efectos de año (AN) y estación de nacimiento (EN), sexo de la cría (SX) y edad de la vaca (EV). La media general para peso al nacimiento fue 34.6 kg, solo los efectos de AN y EN influenciaron (P &lt; 0.05) el peso al nacimiento. El mayor peso se observó en los becerros nacidos en 1994 durante la época de lluvias. Para el caso del PD la media fue de 165.7 kg, los efectos de AN, EN, EV y la correlación de AN x EN fueron estadísticamente significativos (P &lt; 0.05), donde los mayores pesos fueron de los becerros nacidos en el año 1994 durante la época de sequía. Se puede concluir que en este trabajo los factores medioambientales fueron más importantes que los factores genéticos para ambas variables.Resumo. O objetivo deste trabalho foi avaliar a produtividade de touros Charolês (CH), Simental (SM) e Pardo Suíço (PS) com vacas Zebu (CE), PS x CE e CH x CE através dos pesos ao nascimento e à desmama dos bezerros. A fazenda possuía pastagens African Star (Cynodon nlemfuensis) e Guinea (Panicum maximun), utilizadas com pastejo rotacionado. As vacas foram cruzadas por inseminação artificial com sêmen de SM, CH e PS e foram cruzadas com touros CH. Os bezerros foram tatuados na orelha com o número da mãe e pesados nas primeiras 24 horas após o nascimento. Os dados foram analisados pelo método dos mínimos quadrados para determinar os efeitos da estação de nascimento (EN), sexo do bezerro (SX) e idade da vaca (EV). A média geral para os pesos ao desmame dos bezerros foi de 34,6 kg, apenas os efeitos da EN influenciaram (P &lt; 0,05) o peso ao nascer. Os maiores pesos foram observados nos bezerros nascidos na estação chuvosa. Para PD a média foi de 165,7 kg, os efeitos de EN e EV foram estatisticamente significativos (P &lt; 0,05), onde os maiores pesos foram dos bezerros nascidos na estação seca. Pode-se concluir que neste trabalho os fatores ambientais foram mais importantes que os fatores genéticos para ambas as variáveis
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