Constraining non standard recombination: A worked example

We fit the BOOMERANG, MAXIMA and COBE/DMR measurements of the cosmic microwave background anisotropy in spatially flat cosmological models where departures from standard recombination of the primeval plasma are parametrized through a change in the fine structure constant $\alpha$ compared to its present value. In addition to $\alpha$ we vary the baryon and dark matter densities, the spectral index of scalar fluctuations, and the Hubble constant. Within the class of models considered, the lack of a prominent second acoustic peak in the measured spectrum can be accomodated either by a relatively large baryon density, by a tilt towards the red in the spectrum of density fluctuations, or by a delay in the time at which neutral hydrogen formed. The ratio between the second and first peak decreases by around 25% either if the baryon density $\Omega_bh^2$ is increased or the spectral index $n$ decreased by a comparable amount, or if neutral hydrogen formed at a redshift $z_*$ about 15% smaller than its standard value. We find that the present data is best fitted by a delay in recombination, with a lower baryon density than the best fit if recombination is standard. Our best fit model has $z_*= 900$, $\Omega_bh^2=0.024$, $\Omega_mh^2=0.14$, $H_0=49$ and $n=1.02$. Compatible with present data at 95% confidence level $780< z_*<1150$, $0.018<\Omega_bh^2<0.036$, $0.07< \Omega_m h^2 < 0.3$ and $0.9<n<1.2$.Comment: 9 pages, 6 figs. Version accepted for publication in Phys.Rev.

Perceived emotional intelligence as a predictor of depressive symptoms after a one year follow-up during adolescence

Research to date has identified various risk factors in the emergence of depressive disorders in adolescence. There are very few studies, however, which have analyzed the role of perceived emotional intelligence in depressive symptoms longitudinally during adolescence. This work aimed to analyze longitudinal relationships between perceived emotional intelligence and depressive symptoms in adolescence, developing an explanatory model of depression following a one-year follow-up. A longitudinal study was carried out with two waves separated by one year, with a sample of 714 Spanish adolescents. The instruments consisted of self-report measures of depressive symptoms and perceived emotional intelligence. Results underlined gender differences in depressive symptoms and emotional intelligence, and indicated that greater emotional intelligence was associated with a lower presence of depressive symptoms after a one year follow-up. A multiple partial mediation model was developed to explain longitudinally depressive symptoms based on perceived emotional intelligence skills and depressive symptoms. These contributions underscore the need to design programs to prevent depression in adolescence through the promotion of emotional intelligence.peer-reviewe

Hierarchical bioglass scaffolds: Introducing the "milky way" for templated bioceramics

Free standing hierarchical bioglass scaffolds were prepared by the ISISA (ice-segregation-induced self-assembly) method. Commercial low-cost precursors such as Ludox® HS-40 and cow milk were employed as the source of SiO2 and biominerals (Ca(ii), P(v), Na(i) and K(i)), respectively. Then, in a single macroscopic piece, three levels of porosity coexist due to the simultaneous templating effect of ice (macropores), milk (50-200 nm mesopores) and the voids left between preformed Ludox® nano building blocks (2-5 nm mesopores). These low cost and green biological nanotemplates, coupled with the ISISA texturing method, allows the preparation of free standing bioglass monoliths, with hierarchical porosity. The effect of the main preparative variables on the final texture is explored; in vitro biomineralization revealed a well-distributed hydroxyapatite-like nanoparticulated layer within 24 h of exposure to a simulated body fluid.Fil: Onna, Diego Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Minaberry, Yanina Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Jobbagy, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Adults density of Grapholita molesta in cages : Mendoza (Argentina)

Grapholita molesta es una importante plaga que afecta brotes y frutos del duraznero en Mendoza, Argentina. Algunos autores han citado que Carpocapsa pomonella requiere, en condiciones artificiales, una densidad poblacional de 100 adultos para alcanzar una alta fecundidad y que esta situación se puede extender a la especie en estudio. El objetivo del trabajo fue evaluar distintas densidades poblacionales de la especie mediante la fecundidad, viabilidad y longevidad. La especie se crió en una cámara con condiciones abióticas controladas. El diseño fue en bloques al azar para eliminar la influencia de la luz y el desarrollo generacional. Se realizaron cuatro repeticiones. Los resultados se procesaron mediante el programa Statistica. El análisis de los resultados entre bloques y tratamientos no tuvo diferencias significativas por lo que no hubo variación en la incidencia de la luz y el desarrollo generacional. La viabilidad tuvo diferencias significativas entre los tratamientos mientras que la fecundidad y la longevidad no las presentaron. La densidad poblacional influyó positivamente sobre la viabilidad cuando la cantidad de parejas fue la menor y disminuyó al incrementarse la proporción de las mismas. Es decir, el hacinamiento de los individuos afectó la viabilidad de Grapholita molesta pero no la fecundidad ni la longevidad.Grapholita molesta is an important pest that affects buds and fruits of peach tree in Mendoza, Argentina. Some authors have mentioned that Carpocapsa pomonella requires, in artificial conditions, a population density of 100 adults to reach high fecundity and this situation can be extended to Grapholita molesta. This work was done in order to evaluate different population densities of Grapholita molesta by mean of fecundity, viability and longevity. Rearing was made in a chamber with controlled abiotic conditions. Experimental design was blocks at random to eliminate light and generational development influence. It was made 4 replications. Results were processed by mean of Statistica software. Analysis of results between blocks and treatments did not have significant differences reason why there was no variation in the incidence of light and generational development. Viability had significant differences among treatments. Fecundity and longevity did not present significant differences. Population density influenced positively on viability when couple amount was the least, and it decreased when proportion of the same ones was increased. That is to say, individual stacking affected Grapholita molesta viability but it did not affect fecundity nor longevity.Fil: Ribbert, Diego Alfredo. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias BiológicasFil: Marín, María Susana. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias Biológica

The signature of river- and wind-borne materials exported from Patagonia to the southern latitudes: a view from REEs and implications for paleoclimatic interpretations

Riverine and wind-borne materials transferred from Patagonia to the SW Atlantic exhibit a homogeneous rare earth element (REE) signature. They match well with the REE composition of Recent tephra from the Hudson volcano,and hence this implies a dominance of material supplied by this source and other similar Andean volcanoes. Due to the trapping effect of proglacial and reservoir lakes,the larger Patagonian rivers deliver to the ocean a suspended load with a slightly modified Andean signature,that shows a REE composition depleted in heavy REEs. In this paper we redefine Patagonia as a source of sediments,which is in contrast with other sources located in southern South America. Quaternary sediments deposited in the northern and,to a lesser extent, in the southern Scotia Sea, and most of the dust in ice cores of east Antarctica have REE compositions very similar to the loess from Buenos Aires Province and to Patagonian eolian dust. However,we rule out Buenos Aires province as a Holocene major source of sediments. Similarly to Buenos Aires loess (a proximal facies),it is likely that the REE compositions of most sediment cores of the Scotia Sea and Antarctica reflect a distal transport of dust with an admixed composition from two main sources: a major contribution from Patagonia,and a minor proportion from source areas containing sediments with a clear upper crustal signature (e.g.,western Argentina) or from Bolivia’s Altiplano. Evidence indicates that only during the Last Glacial Maximum,Patagonian materials were the predominant sediment source to the southern latitudes

Consumer mobility awareness in named data networks

Mobile data traffic has increased significantly due to the evolution of wireless communication technologies. The Information Centric Network paradigm is considered as an alternative to bypass the restrictions imposed by the traditional IP networks, especially those related with the mobility of its users. Despite the potential advantages of this paradigm regarding mobile wireless environments, several research challenges remain unaddressed, more specifically the ones related with the communication damage caused by handovers. This work presents a Named Data Network (NDN) based solution that supports Consumer mobility. The proposed scheme addresses a mobility manager entity that monitors and anticipates trajectories, while compelling the infrastructure to adjust to the new paths. This process results in an efficient way to manage the Consumers' mobility, and therefore, in a better quality of service to its users. The implementation and evaluation of the proposed solution uses the ndnSIM, through functional and non-functional scenarios, and with real traces of urban vehicular mobility and connectivity. The results show that the proposed solution is superior to the native NDN workflow with respect to content delivery ratio and number of timeouts.info:eu-repo/semantics/publishedVersio

Iron and other transition metals in Patagonian riverborne and windborne materials: Geochemical control and transport to the southern South Atlantic Ocean

The bulk of particulate transition metals transported by Patagonian rivers shows an upper crustal composition. Riverine particulate 0.5 N HCl leachable trace metal concentrations are mainly controlled by Fe-oxides. Complexation of Fe by dissolved organic carbon (DOC) appears to be an important determinant of the phases transporting trace metals in Patagonian rivers. In contrast, aeolian trace elements have a combined crustal and anthropogenic origin. Aeolian materials have Fe, Mn, and Al contents similar to that found in regional topsoils. However, seasonal concentrations of some metals (e.g., Co, Pb, Cu, and Zn) are much higher than expected from normal crustal weathering and are likely pollutant derived. We estimate that Patagonian sediments are supplied to the South Atlantic shelf in approximately equivalent amounts from the atmosphere (30 106 T yr1) and coastal erosion (40 106 T yr1) with much less coming from the rivers (2.0 106 T yr1). Low trace metal riverine fluxes are linked to the low suspended particulate load of Patagonian rivers, inasmuch most of it is retained in pro-glacial lakes as well as in downstream reservoirs. Based on our estimation of aeolian dust fluxes at the Patagonian coastline, the high nutrient-low chlorophyll sub Antarctic South Atlantic could receive 1.0 to 4.0 mg m2 yr1 of leachable (0.5 N HCl) Fe. Past and present volcanic activity in the southern Andes—through the ejection of tephra—must be highlighted as another important source of Fe to the South Atlantic Ocean. Based on the 1991 Hudson volcano eruption, it appears that volcanic events can contribute several thousand-fold the mass of “leachable” Fe to the ocean as is introduced by annual Patagonian dust fallout

Spatial and temporal divergence of the torquatus species group of the subterranean rodent Ctenomys

Subterranean rodents of the genus Ctenomys have experienced an explosive radiation and rapidly colonized the southern cone of South America. The torquatus group, one of the main groups of the genus, comprises several species and species complexes which inhabit the eastern part of the distribution of Ctenomys including southern Brazil, northern and central Uruguay and north-eastern Argentina. This group has undergone a high chromosomal diversification with diploid numbers varying from 41 to 70. The aim of this study was to investigate the origins of the torquatus group as well as its diversification patterns in relation to geography and cladogenesis. Based on mitochondrial cytochrome b nucleotide sequences we conducted a Bayesian multi-calibrated relaxed clock analysis to estimate the ages of the torquatus group and its main lineages. Using the estimated evolutionary rate we performed a continuous phylogeographic analysis, using a relaxed random walk model to reconstruct the geographic diffusion of the torquatus group in a temporal frame. The torquatus group originated during the early Pleistocene between 1.25 and 2.32 million years from the present in a region that includes the northwest of Uruguay and the southeast of the Brazilian state of Río Grande do Sul. Most lineages have dispersed early towards their present distribution areas going through subsequent range expansions in the last 800,000 – 700,000 years. Ctenomys torquatus went through a rapid range expansion for the last 200,000 years, becoming the most widespread species of the group. The colonization of the Corrientes and Entre Ríos Argentinean provinces supposes at least two crossing events across the Uruguay River between 1.0 and 0.5 million years before the present, in the context of a cold and dry paleoenvironment. The resulting temporal and geographic frame enables the comprehension of the incidence of both, the amplitude of distribution areas and divergence times into the patterns of chromosomal diversification found in the group.Fil: Caraballo, Diego Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Rossi, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

La gastronomía sostenible como factor de mejoramiento de la cadena de suministro del sector gastronómico en Bogotá - Colombia.

36 páginasMagíster en Responsabilidad Social y SostenibilidadMaestrí

Fully dynamic and memory-adaptative spatial approximation trees

Hybrid dynamic spatial approximation trees are recently proposed data structures for searching in metric spaces, based on combining the concepts of spatial approximation and pivot based algorithms. These data structures are hybrid schemes, with the full features of dynamic spatial approximation trees and able of using the available memory to improve the query time. It has been shown that they compare favorably against alternative data structures in spaces of medium difficulty. In this paper we complete and improve hybrid dynamic spatial approximation trees, by presenting a new search alternative, an algorithm to remove objects from the tree, and an improved way of managing the available memory. The result is a fully dynamic and optimized data structure for similarity searching in metric spaces.Eje: Teoría (TEOR)Red de Universidades con Carreras en Informática (RedUNCI