850 research outputs found
Deconstructing the I and SLA in ISLA: One curricular approach
Instructed second language acquisition (ISLA) has been referenced in the larger field of the SLA literature for over two and a half decades. Currently, there are several theoretical underpinnings accounting for processes assumed to play a role in ISLA and quite an impressive number of studies have empirically addressed some aspect(s) of ISLA. Recently, a lengthy and relatively cohesive treatise of this substrand of SLA research in relation to both theoretical, empirical, and pedagogical perspectives has been published in two books (cf. Leow, 2015a; Loewen, 2015), and a new model of the L2 learning process in ISLA has been proposed (Leow, 2015a). These publications are timely and important given that the concept of ISLA not only needs to be clearly defined but also situated contextually. To this end, this article (a) revisits current definitions of ISLA in the SLA literature with the aim of identifying specific features of ISLA that underlie such definitions, (b) deconstructs ISLA by probing deeper into what comprises the terms instructed and SLA in ISLA, (c) provides a brief summary of the cognitive processes and variables postulated by the theoretical underpinnings of ISLA and pertinent empirical research, (d) recommends that ISLA be observed from one curricular approach together with its empirical and pedagogical ramifications, and (e) provides some measure of direction future ISLA research may follow
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Duration and cost variability of construction activities: an empirical study
The unique nature of construction projects can mean that construction activities often suffer from duration and cost variability. Because this variability is unplanned, it can present a problem when attempting to complete a project on time and on budget. Various factors causing this variability have been identified in the literature, but they predominantly refer to the nature and/or context of the whole project rather than specific activities. In this paper, the order of magnitude of and correlation between activity duration and cost variability is analyzed in 101 construction projects with over 5,000 activities. To do this, the first four moments (mean, standard deviation, skewness, and kurtosis) of actual versus planned duration and cost (log) ratios are analyzed by project, phase of execution, and activity type. Results suggest that, contrary to common wisdom, construction activities do not end late on average. Instead, the large variability in the activity duration is the major factor causing significant project delays and cost overruns. The values of average activity duration and cost variability gathered in this study will also serve as a reference for construction managers to improve future construction planning and project simulation studies with more realistic data
GoogleWave: Una herramienta para la evaluación de trabajos realizados fuera del aula
La evaluación de los trabajos en grupo es siempre
difÃcil para el profesorado porque éste desconoce
la cantidad de esfuerzo que ha dedicado cada
alumno al trabajo asignado. Este artÃculo
pretende presentar la herramienta Google Wave1
como una herramienta capaz de aportar una serie
de funcionalidades no aportadas anteriormente
por ninguna otra herramienta que facilitan al
profesorado la evaluación del esfuerzo de cada
alumno durante la realización de un trabajo en
grupo.Peer Reviewe
Diseño de una guÃa de prácticas de laboratorio de acuerdo con las orientaciones del EEES
La adaptación de la docencia universitaria al Espacio Europeo de Educación Superior (EEES) supone un cambio en los sistemas de enseñanza actual. En este sentido el desarrollo de guÃas de laboratorio capaces de informar al alumnado, y normalizar la confección y presentación de las prácticas de laboratorio, asegurando una mejor calidad de la docencia y coordinación entre grupos, viene a cumplir con algunos de los objetivos pretendidos en el contexto de la Convergencia Europea. La GuÃa que se presenta, destinada a su empleo en la docencia práctica de una asignatura troncal de la licenciatura en Farmacia en la Universidad de Granada, recoge las indicaciones necesarias para llevar a cabo un trabajo seguro y eficiente en los laboratorios
Symmetric derivatives of parametrized quantum circuits
Symmetries are crucial for tailoring parametrized quantum circuits to
applications, due to their capability to capture the essence of physical
systems. In this work, we shift the focus away from incorporating symmetries in
the circuit design and towards symmetry-aware training of variational quantum
algorithms. For this, we introduce the concept of projected derivatives of
parametrized quantum circuits, in particular the equivariant and covariant
derivatives. We show that the covariant derivative gives rise to the quantum
Fisher information and quantum natural gradient. This provides an operational
meaning for the covariant derivative, and allows us to extend the quantum
natural gradient to all continuous symmetry groups. Connecting to traditional
particle physics, we confirm that our covariant derivative is the same as the
one introduced in physical gauge theory. This work provides tools for tailoring
variational quantum algorithms to symmetries by incorporating them locally in
derivatives, rather than into the design of the circuit.Comment: 22+20 pages, 6+1 figure
Turn on fluorescence sensing of Zn2+ based on fused isoindole-imidazole scaffold
Optical chemosensors caused a revolution in the field of sensing due to their high specificity, sensitivity, and fast detection features. Imidazole derivatives have offered promising features in the literature as they bear suitable donor/acceptor groups for the selective analytes in the skeleton. In this work, an isoindole-imidazole containing a Schiff base chemosensor (1-{3-[(2-Diethylamino-ethylimino)-methyl]-2-hydroxy-5-methyl-phenyl}-2H-imidazo[5,1-a]isoindole-3,5-dione) was de-signed and synthesized. The complete sensing phenomena have been investigated by means of UV-Vis, fluorescence, lifetime measurement, FT-IR, NMR and ESI-MS spectroscopic techniques. The optical properties of the synthesized ligand were investigated in 3:7 HEPES buffer:DMSO medium and found to be highly selective and sensitive toward Zn2+ ion through a fluorescence turn-on response with detection limit of 0.073 µm. Furthermore, this response is effective in gel form also. The competition studies reveal that the response of the probe for Zn2+ ion is unaffected by other relevant metal ions. The stoichiometric binding study was performed utilizing Job’s method which indicated a 1:1 sensor–Zn2+ ensemble. Computational calculations were performed to pinpoint the mechanism of sensin
Fructose metabolism in Chromohalobacter salexigens: interplay between the Embden–Meyerhof–Parnas and Entner–Doudoroff pathways
Background
The halophilic bacterium Chromohalobacter salexigens metabolizes glucose exclusively through the Entner–Doudoroff (ED) pathway, an adaptation which results in inefficient growth, with significant carbon overflow, especially at low salinity. Preliminary analysis of C. salexigens genome suggests that fructose metabolism could proceed through the Entner–Doudoroff and Embden–Meyerhof–Parnas (EMP) pathways. In order to thrive at high salinity, this bacterium relies on the biosynthesis and accumulation of ectoines as major compatible solutes. This metabolic pathway imposes a high metabolic burden due to the consumption of a relevant proportion of cellular resources, including both energy molecules (NADPH and ATP) and carbon building blocks. Therefore, the existence of more than one glycolytic pathway with different stoichiometries may be an advantage for C. salexigens. The aim of this work is to experimentally characterize the metabolism of fructose in C. salexigens.
Results
Fructose metabolism was analyzed using in silico genome analysis, RT-PCR, isotopic labeling, and genetic approaches. During growth on fructose as the sole carbon source, carbon overflow was not observed in a wide range of salt concentrations, and higher biomass yields were reached. We unveiled the initial steps of the two pathways for fructose incorporation and their links to central metabolism. While glucose is metabolized exclusively through the Entner–Doudoroff (ED) pathway, fructose is also partially metabolized by the Embden–Meyerhof–Parnas (EMP) route. Tracking isotopic label from [1-13C] fructose to ectoines revealed that 81% and 19% of the fructose were metabolized through ED and EMP-like routes, respectively. Activities of enzymes from both routes were demonstrated in vitro by 31P-NMR. Genes encoding predicted fructokinase and 1-phosphofructokinase were cloned and the activities of their protein products were confirmed. Importantly, the protein encoded by csal1534 gene functions as fructose bisphosphatase, although it had been annotated previously as pyrophosphate-dependent phosphofructokinase. The gluconeogenic rather than glycolytic role of this enzyme in vivo is in agreement with the lack of 6-phosphofructokinase activity previously described.
Conclusions
Overall, this study shows that C. salexigens possesses a greater metabolic flexibility for fructose catabolism, the ED and EMP pathways contributing to a fine balancing of energy and biosynthetic demands and, subsequently, to a more efficient metabolism.University of Murcia and University of Seville was supported by projects: BIO2015-63949-R, BIO2014-54411-C2-1-REuropa MINECO/FEDER RTI2018-094393-B-C21Fundación Séneca (Grant no. 19236/PI/14
Development and Evaluation of Fuzzy Logic Controllers for Improving Performance of Wind Turbines on Semi-Submersible Platforms under Different Wind Scenarios
Among renewable energy technologies, wind energy features one of the best possibilities for large-scale integration into power systems. However, there are specific restrictions regarding the installation areas for this technology, thus resulting in a growing, yet restricted, rate of penetration of the technology because of the limited viable sites onshore or in shallow waters. In this context, the use of offshore semi-submersible platforms appears as a promising option, which additionally enables the incorporation of other elements, such as wave energy converters or aquaculture. Nevertheless, this kind of offshore facility involves interactions between platform movements and the wind turbine, increasing the complexity of the system, causing traditional control techniques to not be able to fully cope with the dynamics of the system, and thus limiting the efficiency of energy extraction. On the contrary, the use of intelligent control techniques is an interesting option to take full account of the said interactions and to improve energy capture efficiency through the control of the pitch of the blades, especially under turbulent, above-rated wind profiles. This work presents an original fuzzy logic controller that has been validated by comparing it with previously validated controllers, following a developed methodology that allows comparison of controllers for wind turbines in semi-submersible platforms using performance indexes.This work was partially supported by the Ministry of Economy and Competitiveness (Government of Spain) and European Union (RTC-2016-5712-3); by the European Union, CDTI (Spain) and BEISS (UK) through the call H2020 ERA-NET DEMOWIND (WIP10+ project); by the Regional Government of Andalusia and European Union (UMA-CEIATECH-18); and finally, by partial funding for open access charge from the Universidad de Málaga. Partial funding for open access charge: Universidad de Málag
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