3,230 research outputs found
Seasonal decline in breeding performance of the Kelp Gull Larus dominicanus
The effects of timing of breeding on reproductive parameters of Kelp Gulls Larus dominicanus were studied in Patagonia, Argentina, during 1998 and 1999. Yearly and spatial variation in the study were assessed by sampling nests during two field seasons and in different areas within the colony, and accounted for variation with respect to breeding synchrony and breeding density. In both years and in three study areas, individuals laying earlier had higher hatching success, a larger number of chicks fledged, heavier chicks at one month and higher breeding success. Significant variation between study areas within the colony and between years was observed only for breeding success and number of chicks fledged. No effects of breeding synchrony on breeding parameters were detected. Timing of breeding, independent of study year and area, had no effect on either clutch size or egg size. Our results document for the first time the seasonal decline in breeding performance in the Kelp Gull, a species widely distributed in the southern hemisphere.Fil: Garcia Borboroglu, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Moreno, Juan. Consejo Superior de Investigaciones Científicas; EspañaFil: Potti Sánchez, Jaime. Consejo Superior de Investigaciones Científicas; Españ
Educator Responses to Migrant Children in Mexican Schools
A decade-long, five-state, mixed-method study of students encountered in Mexican schools with previous experience in the United States suggests there may be 400,000 such students in educación básica alone (elementary and middle school). The focus here, however, are data from 68 educators asked how they have responded to such students and their families. We offer an emergent taxonomy of teacher sensemaking about these students and teachers’ responsibilities to respond. We then assert that because they are at the interface between a national institution (school) and transnational phenomena (migration), educators can provide key insight into how migration is shaped and negotiated.
Un estudio de una década, en cinco estados, y que utiliza métodos mixtos con estudiantes que se encuentran en escuelas mexicanas con experiencias previas en los Estados Unidos sugiere que se pueden encontrar 400,000 estudiantes de este tipo tan sólo cursando la educación básica (primaria y secundaria). Sin embargo, el enfoque aquí son los datos de 68 educadores a quienes se les preguntó cómo responden a esta clase de estudiantes y a sus familias. Ofrecemos una taxonomía emergente sobre cómo es que los maestros dan sentido a las responsabilidades de tener que responder a este tipo de circunstancias, enfrentadas por estos estudiantes y sus maestros. Procedemos a afirmar que, a causa de que se encuentran en el punto de contacto entre una institución nacional (la escuela) y un fenómeno transnacional (la migración), los educadores pueden proveer información clave sobre cómo es que la migración se define y se negocia
Educator Responses to Migrant Children in Mexican Schools
A decade-long, five-state, mixed-method study of students encountered in Mexican schools with previous experience in the United States suggests there may be 400,000 such students in educación básica alone (elementary and middle school). The focus here, however, are data from 68 educators asked how they have responded to such students and their families. We offer an emergent taxonomy of teacher sensemaking about these students and teachers’ responsibilities to respond. We then assert that because they are at the interface between a national institution (school) and transnational phenomena (migration), educators can provide key insight into how migration is shaped and negotiated.
Un estudio de una década, en cinco estados, y que utiliza métodos mixtos con estudiantes que se encuentran en escuelas mexicanas con experiencias previas en los Estados Unidos sugiere que se pueden encontrar 400,000 estudiantes de este tipo tan sólo cursando la educación básica (primaria y secundaria). Sin embargo, el enfoque aquí son los datos de 68 educadores a quienes se les preguntó cómo responden a esta clase de estudiantes y a sus familias. Ofrecemos una taxonomía emergente sobre cómo es que los maestros dan sentido a las responsabilidades de tener que responder a este tipo de circunstancias, enfrentadas por estos estudiantes y sus maestros. Procedemos a afirmar que, a causa de que se encuentran en el punto de contacto entre una institución nacional (la escuela) y un fenómeno transnacional (la migración), los educadores pueden proveer información clave sobre cómo es que la migración se define y se negocia
Bringing action language C+ to normative contexts: preliminary report
C+ is an action language for specifying and reasoning about the e ects of actions and the persistence of facts over time. Based on it. we present CN+, an operational enhanced form of C+ designed for representing complex normative systems and integrate them easily into the semantics of the causal theory of actions. The proposed system contains a particular formalization of norms using a life-cycle approach to capture the whole normative meaning of a complex normative framework. We discuss this approach and illustrate it with examples.Peer ReviewedPostprint (author’s final draft
What is that thing called internal quality assurance system?
Purpose: The main purpose of this paper is to explore and to propose a comprehensive definition and conceptualization of an Internal Quality Assurance System (IQAS) for Higher Education Institution (HEI) by using Work Systems Theory (WST) as a theoretical lens.
Design/methodology/approach: The paper follows a multiple method research approach by grounding on a literature review and validating against a published study case.
Findings: After analysing a number of IQAS definitions, the paper shows how these systems can be defined as a specific case of a “work system”, the main unit of analysis and conceptualization provided by WST. To further demonstrate the academic relevance and practical applicability of the proposed conceptualization, we provide a concrete instantiation as a “work system” of the IQAS implemented in a real HEI case.
Research limitations: Additional instantiations of IQAS implemented in other different real contexts should be conducted to foster the generalizability of the proposed framework.
Practical implications: Using the same theoretical lens as a reference point, the paper provides insights and directions for further research as well as potential future uses and practical applications of the derived conceptualization.
Originality/value: To our best knowledge, this is the first comprehensive formal IQAS definition and first WST-based conceptualizing an IQAS for HEIs.Peer ReviewedPostprint (published version
Exploring the ring-closing metathesis for the construction of the solomonamide macrocyclic core: identification of bioactive precursors
New synthetic strategies directed toward the novel cyclopeptides solomonamides have been explored utilizing an olefin metathesis as the key reaction. In the various strategies investigated, we worked on minimally oxidized systems, and the olefin metathesis reaction demonstrated efficiency and validity for the construction of the macrocyclic core. The described synthetic strategies toward the solomonamides are well suited for the subsequent access to the natural products and represent flexible and diversityoriented routes that allow for the generation of a variety of analogues via oxidative transformations. In addition, preliminary biological evaluations of the generated solomonamide precursors revealed antitumor activity against various tumor cell lines.This work was financially supported by the Ministerio de Economía y Competitividad (MINECO) (ref BIO2014-56092-R, CTQ2014-60223-R and CTQ2016-76311-R) and Junta de Andalucía and “Fondo Europeo de Desarrollo Regional-FEDER” (P12
CTS-1507). I.C.-S. thanks Ministerio de Educación, Cultura y Deporte for a predoctoral fellowship (FPU programme)
El modelado proteico como herramienta para el análisis funcional de efectores haustoriales de Podosphaera xanthii
Los oídios son patógenos biotrofos obligados que requieren células vegetales vivas para
completar su ciclo de vida asexual. Podosphaera xanthii, principal agente causal del oídio
de las cucurbitáceas, es uno de los patógenos más destacados que limitan la productividad
de estos cultivos en España. Este hongo desarrolla unas estructuras especializadas de
parasitismo denominadas haustorios que prosperan dentro de las células epidérmicas y
son responsables de la relación directa entre el patógeno y el huésped, participando en la
absorción de nutrientes de la planta y en la liberación de efectores en las células del
huésped.
Con el objetivo de identificar genes clave para la patogénesis de Podosphaera xanthii y,
partiendo del transcriptoma haustorial y del correspondiente secretoma analizados
previamente en nuestro laboratorio, se ha realizado el modelado de las proteínas asociadas
a diferentes contigs que carecen de anotación funcional y que pudieran corresponder a
proteínas efectoras secretadas candidatas, con la intención de dilucidar su posible función
en la interacción patógeno-planta mediante similaridad estructural con proteínas
cristalografiadas disponibles en bases de datos.
Aunque esta aproximación no es definitiva, nos aporta una valiosa información para
realizar el posterior análisis funcional in vivo e identificar aquellos genes clave en la
patogénesis de P. xanthii.
Los resultados obtenidos arrojan una serie de proteínas cuyas funciones, según los
modelos predichos y su comparación posterior con proteínas cristalografiadas, parecen
estar directamente relacionadas con distintos aspectos de la patogénesis. Por ello, hemos
establecido el modelado proteico como el primer paso del proceso de análisis funcional
de proteínas secretadas efectoras candidatas sin función conocida de P. xanthii.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Global Positioning System Analysis of Physical Demands in Elite Women’s Beach Handball Players in an Official Spanish Championship
This cross-sectional study aims to analyze the physical demands of elite beach handball players during an official competition. Nine elite female (mean age: 24.6 ± 4.0 years; body weight: 62.4 ± 4.6 kg; body height: 1.68 ± 0.059 m; training experience: 5 years; training: 6 h/week) beach handball players of the Spanish National Team were recruited for this study. A Global Positioning System was incorporated on each player’s back to analyze their movement patterns. Speed and distance were recorded at a sampling frequency of 15 Hz, whereas acceleration was recorded at 100 Hz by means of a built-in triaxial accelerometer. The main finding of the study is that 53% of the distance travelled is done at speeds between 1.5 and 5 km/h and 30% of the distance is between 9 and 13 km/h (83% of the total distance covered), which shows the intermittent efforts that beach handball involves at high intensity, as reflected in the analysis of the internal load with 62.82 ± 14.73% of the game time above 80% of the maximum heart rate. These data help to orientate training objectives to the physical demands required by the competition in order to optimize the players’ performance
Easy asteroid phase curve fitting for the Python ecosystem: Pyedra
A trending astronomical phenomenon is the variation in brightness of asteroids. This can be caused by its rotation on its own axis and/or its position relative to the sun. The latter behavior can be visualized on a phase curve, which shows the reduced magnitude as a function of the phase angle. To enable the comparison between several models for the dependence of reduced magnitude on phase angle we present a Python package called Pyedra. Pyedra implements three phase-curve-models, and also provides tools for visualization as well as integration with external datasets. The package is fully documented and tested following a strict quality-assurance workflow, with a user-friendly programmatic interface. In future versions, we will include more models, and additional estimation of quantities derived from parameters such as diameter and different albedos, and correlation of information of physical and orbital parameters.Fil: Colazo, Milagros Rita. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Cabral, Juan Bautista. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chalela Garcia, Martin. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Sánchez, Bruno Orlando. University of Duke; Estados Unido
A comparison of high-order time integrators for thermal convection in rotating spherical shells
A numerical study of several time integration methods for solving the threedimensional
Boussinesq thermal convection equations in rotating spherical shells
is presented. Implicit and semi-implicit time integration techniques based on
backward differentiation and extrapolation formulae are considered. The use of
Krylov techniques allows the implicit treatment of the Coriolis term with low
storage requirements. The codes are validated with a known benchmark, and
their efficiency is studied. The results show that the use of high order methods,
especially those with time step and order control, increase the efficiency of the
time integration, and allows to obtain more accurate solutions.Postprint (author’s final draft
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