1,692 research outputs found
On the Sensitivity of Massive Star Nucleosynthesis and Evolution to Solar Abundances and to Uncertainties in Helium Burning Reaction Rates
We explore the dependence of pre-supernova evolution and supernova
nucleosynthesis yields on the uncertainties in helium burning reaction rates.
Using the revised solar abundances of Lodders (2003) for the initial stellar
composition, instead of those of Anders & Grevesse (1989), changes the
supernova yields and limits the constraints that those yields place on the
12C(a,g)16O reaction rate. The production factors of medium-weight elements (A
= 16-40) were found to be in reasonable agreement with observed solar ratios
within the current experimental uncertainties in the triple alpha reaction
rate. Simultaneous variations by the same amount in both reaction rates or in
either of them separately, however, can induce significant changes in the
central 12C abundance at core carbon ignition and in the mass of the supernova
remnant. It therefore remains important to have experimental determinations of
the helium burning rates so that their ratio and absolute values are known with
an accuracy of 10% or better.Comment: Accepted for publication by the Astrophysical Journa
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Digital artefacts for reflection on identity in the first year of teacher education: the teacher I want to be
This paper presents an analysis of digital reflective narratives of identity constructed by student teachers in their first year in a Spanish University. The literature review demonstrates the multidimensional nature of teacher identity, showing that, during the transition of their first year at University, student teachers’ ideas of identity reflect a highly emotional and committed stance on
childhood and social justice. The innovative approach taken in the current work includes a review of the possibilities of digital artefacts, as OER, for reflection. The conclusion discusses the importance of scaffolding approaches to the development of teacher identity through a reflective methodology
Analysis of Participation in Multifunctional Agriculture: U.S. Rice Farms
Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional relationships we estimate a binary logistic model where the dependent variable takes a value equal to one if the farm operator reports in the ARMS survey participation in conservation programs, recreation or agritourism. Results show that the level of farm operator education and cultural practices that use conservation technical assistance are significant at the 0.01 and 0.10 levels, respectively, in explaining participation. Farm financial characteristics were not significant. Location (state where operator is located) is also not significant.multifunctional agriculture, agri-environmental policy, rice, logistic model, Agricultural and Food Policy, Land Economics/Use, Q18, Q26, Q28,
Analysis of Participation in Multifunctional Agriculture: U.S. Rice Farms
Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional relationships we estimate a binary logistic model where the dependent variable takes a value equal to one if the farm operator reports in the ARMS survey participation in conservation programs, recreation or agritourism. Results show that the level of farm operator education and cultural practices that use conservation technical assistance are significant at the 0.01 and 0.10 levels, respectively, in explaining participation. Farm financial characteristics were not significant. Location (state where operator is located) is also not significant.multifunctional agriculture, agri-environmental policy, rice, logistic model, Agricultural and Food Policy, Community/Rural/Urban Development, Crop Production/Industries, Environmental Economics and Policy, Land Economics/Use, Q18, Q26, Q28,
The development of the reflective practitioner through digital storytelling
This paper presents a multiple case study on the use of digital storytelling to support the development of reflection and digital skills in professional education. Students from two universities, one group studying health and social care, the other training to be teachers, were asked to produce two artefacts, at the beginning and end of their respective modules, in which they reflected on the aspects of professional and personal learning. The artefacts, some of which were produced in groups, others by individual students, were analysed for recurring themes, levels of reflection and digital competence, particularly in the use of open educational resources. Findings from the analysis support the use of digital storytelling methods to develop a range of key skills pertinent to professional education in general but concluded that the deeper levels of reflection may be most evident in individual artefacts produced in the later stages of professional education. The study provides some important insights for teaching and learning in professional education as it suggests that digital storytelling provides a highly engaging way of introducing both reflective and open educational practices
Sertaconazole antifungal profile determined by a microdilution method versus nine topical substances against dermatophyte fungi
Antifungal activity and in vitro inhibition time for sertaconazole (STZ) and 9 other topical drugs, namely amorolfine, bifonazole, clotrimazole, econazole, ketoconazole, miconazole, oxiconazole, terbinafine, and tioconazole were determined against 124 clinical isolates of dermatophyte (12 species) fungi by the microdilution method in a liquid medium and the measurement of optical density. STZ's antifungal activity was not always affected by the tested dermatophyte genus, as was the case with the remaining antifungals. In vitro antifungal activity was at the same level for all the studied azole derivatives, but, in terms of partial inhibitory concentrations, STZ starts its in vitro inhibitory activity in a shorter time than the other tested substances, particularly in those incubation periods when the growth of the dermatophyte fungi was more developed.Fil: Carrillo Muñoz, A. J.. No especifĂca;Fil: Tur Tur, C.. No especifĂca;Fil: Cárdenes, D.. No especifĂca;Fil: Rojas, Florencia Dinorah. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; ArgentinaFil: Giusiano, Gustavo Emilio. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; Argentin
Els cnidaris bentònics
En aquest treball es presenten 85 espècies de cnidaris bentònics trobats als fons que envolten l'Arxipèlag de Cabrera. També es fa esment de la distribució bionòmica de les espècies més representatives i es compara la fauna trobada amb la de la immediata costa de Mallorca, la costa catalana, i, en general, les del litoral de la Mediterrà nia central i occidental.A check-list of the benthic Cnidaria inhabiting the Archipelago of Cabrera is presented, with comments on the bionomic distribution of the most representative species. The faunistic composition and the species distribution is very similar to the other Balearic islands and the species pool is representative of the coastal Mediterranean Cnidarian fauna
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