365 research outputs found
Selection in initial and return migration: Evidence from moves across Spanish cities
This paper investigates the sorting of more productive workers into denser cities using administrative data for Spain that follow individuals continuously throughout their working lives. Migrants who move to denser cities are positively selected in terms of education, occupational skills, and individual productivity as proxied by premigration position in the local earnings distribution. However, not everyone is able to benefit equally from denser cities and this leads to a second round of sorting. Returnees are not only exante less productive than permanent migrants, but are also those who, following the first move, have least boosted up their earnings in denser cities.selection; urban migration; return migration; skill sorting
City of dreams
Bigger cities offer more valuable experiences and opportunities in exchange for higher housing costs. While higher-ability workers benefit more from bigger cities, they are not more likely to move to one. Our model of urban sorting by workers with heterogeneous self-confidence and ability suggests flawed self-assessment is partly to blame. Analysis of the National Longitudinal Survey of Youth 1979 data shows that, consistent with our model, young workers with high self-confidence are more
likely to locate in a big city initially. For more experienced workers, ability plays a stronger role in determining location choices, but the lasting impact of earlier choices dampens their incentives to move
City of dreams
Higher ability workers benefit more from bigger cities while housing costs there are higher for everyone, and yet there is little sorting on ability. A possible explanation is that young individuals have an imperfect assessment of their ability, and, when they learn about it, early decisions have had a lasting impact and reduce their incentives to move. We formalize this idea through an overlapping generations model of urban sorting by workers with heterogenous ability and self-confidence, with the latter defined as individuals’ assessment of their own ability. We then test the location patterns predicted by the model over the life cycle on panel data from the National Longitudinal Survey of Youth 1979. We find that the city-size choices of individuals at different stages vary with ability and self-confidence in a way that closely matches our theoretical predictions
EL DESAFIO ACTUAL: IMPLEMENTACION DE UNA INNOVACIÓN PEDAGÓGICA, EL CICLO FORMACIÓN BÁSICA
Las políticas públicas actuales para el sector de educación Superior están dirigidas hacia la implementación de Ciclos Generales de Conocimientos Básicos, los cuales se han constituido en un desafío para las instituciones universitarias. La Facultad de Ciencias de la Salud de la Universidad Nacional de Entre Ríos ha tomado como propio dicho desafío, ya que constituye una estrategia dirigida a la flexibilización de las estructuras académicas, dado que la rigidez detectada en la currícula de las carreras, y la cristalización de las mismas genera un desfasaje entre la formación recibida y la requerida en los contextos actuales donde la generación, transferencia y distribución del conocimiento y formas de pensamiento resultan centrales. La comunidad educativa de nuestra institución ha venido trabajando desde hace un año en el diseño y la implementación de un Ciclo de Formación Básica Común a las cinco carreras lo que implicó los cambios curriculares de las mismas. En esta ponencia se relata el camino recorrido, algunas tensiones detectadas en el proceso de implementación del Ciclo
Predictive Control Applied to a Solar Desalination Plant Connected to a Greenhouse with Daily Variation of Irrigation Water Demand
The water deficit in the Mediterranean area is a known matter severely affecting agriculture. One way to avoid the aquifers’ exploitation is to supply water to crops by using thermal desalination processes. Moreover, in order to guarantee long-term sustainability, the required thermal energy for the desalination process can be provided by solar energy. This paper shows simulations for a case study in which a solar multi-effect distillation plant produces water for irrigation purposes. Detailed models of the involved systems are the base of a predictive controller to operate the desalination plant and fulfil the water demanded by the crops
Marine-derived fungi as biocatalysts
Marine microorganisms account for over 90% of ocean biomass and their
diversity is believed to be the result of their ability to adapt to extreme conditions
of the marine environment. Biotransformations are used to produce a wide range
of high-added value materials, and marine-derived fungi have proven to be a
source of new enzymes, even for activities not previously discovered. This review
focuses on biotransformations by fungi from marine environments, including
bioremediation, from the standpoint of the chemical structure of the substrate,
and covers up to September 202
Cutting down on the grog: the crystallisation of Neolithic ceramic traditions at Cova d’En Pardo (Alicante, Spain) and cultural change in the western Mediterranean basin (mid-6th and 5th millennia cal. BC)
This paper presents the characterisation of 48 ceramic samples from Cova d’En Pardo (Alicante, Spain). Provenance and technology analysis are carried out on materials dated back to different Early and Middle Neolithic cultural phases, including pioneer and Epicardial levels, poorly known in the area. The techniques employed are optical petrography and scanning electron microscope. Two main fabrics were identified, characterised by the heavy presence of temper (grog and calcite), along with five minor petrographic classes, including two imports, one of them probably from southern Iberia. The comparison among occupational phases within the site reveals changes along the stratigraphic series, especially during the transition from the 6th to 5th millennia cal. BC, which is reflected in temper choice. Evidence from the earliest occupation of the site also agrees with the picture of discontinuity previously observed on nearby contexts between pioneer and traditional Cardial ceramic technology, which might be connected to neolithization routes. Firing technology is characterised by the occurrence of microstructure gradients and signs of fast heating rates.Sample preparation and analyses were funded by the projects NEOMEDPOT (Marie Skłodowska-Curie program, European Commission, grant number 659466) and Espacios sociales y espacios de frontera durante el calcolítico y la Edad del Bronce en el Levante de la península Ibérica (HAR2016-76586-P, Ministerio de Economía y Competitividad and FEDER). Miguel del Pino is a postdoctoral researcher within the Viera y Clavijo program, funded by the Universidad de Las Palmas de Gran Canaria (Spain). The initial draft of the paper was finished while a postdoctoral researcher within the APOSTD program funded by the Generalitat Valenciana and FEDER funds (Spain)
Fsy1, the sole hexose-proton transporter characterized in Saccharomyces yeasts, exhibits a variable fructose:H+ stoichiometry
AbstractIn the model yeast Saccharomyces cerevisiae, hexose uptake is mediated exclusively by a family of facilitators (Hxt, hexose transporters). Some other Saccharomyces species (e.g. Saccharomyces bayanus and Saccharomyces pastorianus) possess, in addition, a specific fructose transporter (Fsy1, fructose symporter) that has been previously described to function as a proton symporter. In the present work, we compared growth of a yeast strain in which FSY1 occurs naturally in anaerobic, fructose- and glucose-limited chemostat cultures. Especially at low specific growth rates, fructose-proton symport was shown to have a strong impact on the biomass yield on sugar. We subsequently employed energized hybrid plasma membrane vesicles to confirm previous observations concerning the mode of operation and specificity of Fsy1 mediated transport. Surprisingly, these experiments suggested that the carrier exhibits an unusual fructose:H+ stoichiometry of 1:2. This energetically expensive mode of operation was also found consistently in vivo, in shake flask and in chemostat cultures, and both when Fsy1 is the sole transporter and when the Hxt carriers are present. However, it is observed only when Fsy1 is operating at higher glycolytic fluxes, a situation that is normally prevented by downregulation of the gene. Taken together, our results suggest the possibility that fructose symport with more than one proton may constitute an energetically unfavorable mode of operation of the Fsy1 transporter that, in growing cultures, is prevented by transcriptional regulation
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