3,025 research outputs found
Análisis de la alimentación de estadios larvarios de Sardina pilchardus (Walbaum, 1792) en el mar Cantábrico central
Diet analysis of larval fish may clarify the role that zooplankton—not only its abundance but also its size structure and taxonomic composition—may have on larval growth and subsequent recruitment levels. Taking into account the increase in size during larval stages, we followed a larval size-dependent approach for the analysis of prey size in the diet of larval sardine (Sardina pilchardus). Studies on feeding patterns of clupeid larvae typically involve a problem due to regurgitation and defecation of gut contents during capture. Therefore, an alternative sampling method was tested in this study, but no significant differences from conventional methods were found. Despite the low feeding incidence observed (23%), we found a circadian feeding pattern with the highest mean gut contents after dawn, decreasing during the day and with the lowest values at night. Diet was mostly composed of copepod developmental stages, mainly nauplii, and prey size increased with larval size following a power function. Maximum and mean prey size were related to larval mouth gape, though other factors may be restricting the maximum prey size ingested, since most prey width values were between 20 and 40% of larval mandible width.El análisis de la dieta de las larvas de peces puede clarificar el papel que el zooplancton, no solo su abundancia sino también su estructura de tamaños y su composición taxonómica, pueden tener en el crecimiento larvario y los subsecuentes niveles de reclutamiento. Teniendo en cuenta el incremento de tamaño durante los estadíos larvarios, hemos seguido una aproximación dependiente del tamaño para el análisis del tamaño de presa en la dieta de larvas de sardina (Sardina pilchardus). Los estudios sobre los patrones de alimentación de las larvas de clupeidos suelen presentar problemas debido a la regurgitación y defecación de los contenidos digestivos durante la captura. En este sentido, en el presente estudio se probó un nuevo método de muestreo pero no se encontraron diferencias significativas respecto a los métodos convencionales. A pesar de la baja incidencia alimenticia observada (23%), encontramos un patrón alimenticio circadiano con valores medios de contenidos digestivos más elevados después del amanecer, que decrecen durante el día y se minimizan por la noche. La dieta se compuso fundamentalmente de estadíos de desarrollo de copépodo, sobre todo nauplii, y el tamaño de presa aumentó con el tamaño de larva siguiendo una función potencial. El tamaño máximo y medio de presa se relacionó con la apertura bucal de las larvas, aunque otros factores pueden restringir el tamaño máximo de presa ingerida, ya que el tamaño de la mayoría de las presas se encontró entre el 20 % y el 40 % de la anchura de mandíbula larvaria
A Service based Development Environment on Web 2.0 Platforms
Governments are investing on the IT adoption and promoting the socalled e-economies as a way to improve competitive advantages. One of the main government’s actions is to provide internet access to the most part of the population, people and organisations. Internet provides the required support for connecting organizations, people and geographically distributed developments teams. Software developments are tightly related to the availability of tools and platforms needed for products developments. Internet is becoming the most widely used platform. Software forges such as SourceForge provide an integrated tools environment gathering a set of tools that are suited for each development with a low cost. In this paper we propose an innovating approach based on Web2.0, services and a method engineering approach for software developments. This approach represents one of the possible usages of the internet of the future
Size-dependent behaviour of hard rock under triaxial loading
Understanding size effects is important to rigorously analyse the behaviour of rocks and rock masses at different scales and for different applications. A number of empirical and numerical studies have included size effects on the uniaxial compressive strength of different rocks, but only few have focussed on the triaxial compressive strength. In this study, several triaxial tests were conducted on granite samples at different confinements (from 0.2 to 15 MPa) and sizes (from 30 to 84 mm in diameter). The most relevant strength parameters were recovered including peak and residual strengths, orientation and frictional response of shear bands. Size effects were observed to be less dominant at high confining pressures for both peak and residual strengths. The resulting data were analysed in the context of size-dependent rock strength theories. For peak strength analyses, the unified size effect law (USEL) and the improved unified size law (IUSEL) were used, in which the double trends, ascending descending behaviours were observed. Size-dependent Hoek–Brown modified failure criteria based on USEL and IUSEL were fit to peak strengths exhibiting a good agreement between the models and the laboratory data. The brittle-ductile transition and the frictional behaviour of shear band under triaxial loading were also analysed. A clear brittle behaviour was particularly observed in samples with large-diameters tested at low confinements. Finally, in regards to frictional behaviour, the shear band angle found to be affected by both confinement and sample size.Ministerio de Ciencia e Innovación | Ref. PRE2019-087397Ministerio de Ciencia e Innovación | Ref. RTI2018-093563-B-I00Universidade de Vigo/CISU
Microarrays as Platform for Multiplex Assays in Biomarker and Drug Discovery
Despite the tremendous advances in the understanding of the molecular mechanisms and the complexity of the diseases is one of the present challenges for the scientific community; then, novel strategies are required to be designed and developed for effective strategies for early diagnosis and treatment. As many cellular alterations are observed at protein level, high-throughput assays are dramatically needed for biomarker discovery. Herein, we describe advantages and limitations of protein microarrays, as proteomics strategy useful for multiplex and high-throughput protein characterization in clinical samples. Finally, a few examples are discussed; mostly of them related to currently disease biomarkers already identified in proximal fluids by protein arrays are discussed
Toppling susceptibility of a single rock block resting on a regularly rough base
Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGToppling of individual rock blocks resting on an inclined surface has often been observed in nature. This instability mechanism has typically been analysed for simple block geometries, considering the contact between the block and the base where it lies is a planar surface. In this study, the authors analyse the case where this contact is a regularly rough surface. To do that, the authors resort to analytical limit equilibrium formulations, laboratory physical models and discrete element methods. All these approaches show a consistent trend of behaviour, where roughness does affect the toppling response. Regularly rough surfaces are studied in detail and a general analytical formulation able to show the potential influence of roughness on the block toppling response is derived. Additionally, some considerations are provided regarding the combined effects of rough bases and rounded corners on toppling stability. The authors show how under particular circumstances, roughness can control the potential failure mechanism of a block to produce toppling instead of sliding, and they eventually discuss the impact of rough bases on the toppling response of natural rock blocks.Agencia Estatal de Investigación | Ref. RTI2018-093563-B-I0
Language and Cultural Awareness of a Non-Native ESP Teacher
Introduction. The relation between culture and language is a central issue in foreign language teaching and research where the need to give cultural content the same value as language content and language skills has been stressed. However, conceptualization of teacher language awareness, by focusing largely on formal aspects of language, largely neglects culture as a component of teacher cognition. This paper expands the category of ESP-teacher language awareness suggesting the inclusion of cultural awareness as a separate component of teacher cognition. This concept extension actualizes ESP teaching in the situation shaped by unprecedented mobility and intercultural contacts.
Materials and Methods. The historic-logical method was used to determine shortcomings of pedagogical experience and the need to teach culture in ESP. Grounded theory, as an inductive methodology, was utilized to generate conceptual expansion theoretically tied with research in medical and business communication as well as with data on population movement and international s cientific cooperation.
Results. We defined ESP-cultural knowledge as a system comprising the permanent (know-that) and temporary (know-of) cultural manifestations in a society as well as how they are manifested through language (know-how). That system practical representation is exemplified in medicine and business English discourse. The study expands the structure of ESP-TLA, claiming the focus on cultural awareness as part of ESP discourse which fosters cultural-response education.
Discussion and Conclusion. Such claim is pertinent to practitioners involved in the tourism industry, health care, economics, and academic activities such as research and development. This paper is relevant for teachers of English for Specific purposes in the fields mention ed above as well as for researchers engaged in analyzing the problems and methods of teaching a foreign language. However, because of the multiple manifestations and complexity of student motivation to get ESP course, the paper acknowledges the difficulties in addressing cultural content salient to all student s in class, an aspect meriting further research
Prevalence of intestinal parasitic infection among children from a shanty town in Tucuman, Argentina
A parasitological survey was conducted in children living in a poor area next to a drainage channel, in Tucumán province, Argentina. Stool specimens from 115 children were collected and samples were analyzed by direct microscopy examination and concentration techniques. The prevalence rate of intestinal parasites infection was high (78.3%) and Blastocystis hominis was the most frequent protozoan parasite found (68.9%) followed by Giardia intestinalis (33.3%), Entamoeba coli (24.4%), Endolimax nana (12.2%), Chilomastix mesnili (5.6%) and Iodamoeba bütschlii (2.2%). Ascaris lumbricoides was the most prevalent intestinal helminth, with an infection frequency of 38.9%, followed by Trichuris trichiura (13.3%), Strongyloides stercoralis (13.3%), Hymenolepis nana (7.8%) and Enterobius vermicularis (3.3%). Multiple parasitic infections were also high, affecting 71.1% of infected population. These results indicate that sanitary policies, including health care and sanitary education have been inadequate for the control of intestinal parasitism in this high-risk population. Implementation of sanitation programs is a basic need and a joint collaboration between public servant and health professionals should be a priority.Fil: Dib, Julian Rafael. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Fernandez Zenoff, Maria Veronica. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Oquilla, Juana del Valle. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Lazarte, S.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Gonzalez, Silvia Nelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentin
Sub-micro- and nano-sized polyethylene terephthalate deconstruction with engineered protein nanopores
The identification or design of biocatalysts to mitigate the accumulation of plastics, including sub-micro- and nano-sized polyethylene terephthalate (nPET), is becoming a global challenge. Here we computationally incorporated two hydrolytic active sites with geometries similar to that of Idionella sakaiensis PET hydrolase, to fragaceatoxin C (FraC), a membrane pore-forming protein. FraCm1/m2 could be assembled into octameric nanopores (7.0 nm high × 1.6–6.0 nm entry), which deconstructed (40 °C, pH 7.0) nPET from GoodFellow, commodities and plastic bottles. FraCm1 and FraCm2 degrade nPET by endo- and exo-type chain scission. While FraCm1 produces bis(2-hydroxyethyl) terephthalate as the main product, FraCm2 yields a high diversity of oligomers and terephthalic acid. Mechanistic and biochemical differences with benchmark PET hydrolases, along with pore and nPET dynamics, suggest that these pore-forming protein catalytic nanoreactors do not deconstruct macro-PET but are promising in nanotechnology for filtering, capturing and breaking down nPET, for example, in wastewater treatment plants.This study was conducted under the auspices of the FuturEnzyme Project funded by the European Union’s Horizon 2020 Research and Innovation Programme under the auspices of the FuturEnzyme Project (grant agreement no. 101000327) and the PlasticsFatE project (grant agreement no. 95921), and Horizon Europe Research and Innovation Programme under grant agreement no. GA101060625 (Nymphe project). We also acknowledge financial support under grants PID2020-112758RB-I00 (M.F.), PDC2021-121534-I00 (M.F.), TED2021-130544B-I00 (M.F.), PID2019-106370RB-I00 (V.G.) and PID2019-105838RB-C31 (F.J.P.) from the Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (AEI) (Digital Object Identifier MCIN/AEI/10.13039/501100011033), Fondo Europeo de Desarrollo Regional (ERDF) A way of making Europe and the European Union NextGenerationEU/PRTR, UCM-Banco Santander Grants PR87/19-22556 and PR108/20-26896 and UnaEuropa (Unano) SF2106 (to A.M.P.). S.G.-L. was supported by a Real Colegio Complutense Postdoctoral Fellowship for Distinguished Junior Scholars. S.R. thanks the Spanish Ministry of Science and Innovation for a PhD fellowship (FPU19/00608). D.H.-M. thanks Complutense University of Madrid and Banco Santander for a PhD fellowship (CT82/20/CT83/20). A.R.-M. thanks the Spanish Ministry of Science and Innovation for a PhD fellowship (PRE2020-091825) and the project PID2019-106370RB-I00. We thank M. J. Vicente for the ESI–MS analysis, performed at the Servicio Interdepartamental de Investigación (SIDI) from the Autonomous University of Madrid, Spain.Peer Reviewed"Article signat per 16 autors/es: Ana Robles-Martín, Rafael Amigot-Sánchez, Laura Fernandez-Lopez, Jose L. Gonzalez-Alfonso, Sergi Roda, Víctor Alcolea-Rodriguez, Diego Heras-Márquez, David Almendral, Cristina Coscolín, Francisco J. Plou, Raquel Portela, Miguel A. Bañares, Álvaro Martínez-del-Pozo, Sara García-Linares, Manuel Ferrer & Víctor Guallar"Postprint (published version
Study of size effects on the peak and residual strength of intact and artificially fissured granite samples
There are not many studies on jointed rock specimens, which can be considered small scale rock mass analogs. On the other hand, the scale effects in the mechanical properties of such samples have seldom been studied. With the aim of continuing previous research on intact granite rocks, the authors have carried out sets of 25 stress-strain triaxial compressive tests on 1 sub-vertical and 2 sub-horizontal 38 mm, 54 mm and 84 mm diameter jointed granite specimens at various confinements. Peak and residual strength values were obtained and compared to those recovered form intact rock samples. Results suggest that peak strength follows similar trends with scale to those observed on intact rock, even if lower strength values are logically recorded. Regarding residual strength, the obtained results are in line with those observed trends for standard size samples, showing a similar trend for all cases independently of scale, even if we observe larger variability for jointed samples. The authors have also compared the values fitting the generalized Hoek-Brown criterion for rock masses to better understand the behavior in relation to sample size. So scale effects clearly appear on jointed rock peak strength of jointed sample; even if residual strength seems hardly affected by scale.Agencia Estatal de Investigación | Ref. RTI2018-093563-B-I0
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