518 research outputs found
The hammock: a reservoir of allergens
INTRODUCTION: Asthma affects approximately 10% of the world's population. Sensitization to allergens is an important risk factor, and exposure to allergens is associated with disease severity. METHODS: We performed skin tests to evaluate allergen sensitization to mites, cockroaches, cats, dogs, and molds in 73 asthmatic patients. Enzyme Linked Immunosorbent Assay was used to assay the mite and cockroach allergens found in dust from the bedding, hammocks, bedroom floors, living rooms, and kitchens of 29 patients and 14 controls. RESULTS: Fifty patients (68.5%) had positive skin test responses. There were positive responses to D. pteronyssinus (52.0%), B. tropicalis (53.4%), T. putrescentiae (15.0%), E. maynei (12.3%), L. destructor (8.2%), B. germanica (20.5%), P. americana (21.9%), Felis catus (10.9%), C. herbarium (2.7%), A. alternata (4.1%), and P. notatun (1.3%). The exposure to mite and cockroach allergens was similar in the patients and the controls. The Dermatophagoides pteronyssinus Group 1 levels were highest in the beds and hammocks. The Blattella germanica Group 1 levels were highest in the kitchens, living rooms and hammocks. DISCUSSION: The positive skin tests to mites, cockroaches and cats were consistent with previous studies. D pteronyssinus was the most prevalent home dust mite, and hammocks were a source of allergens. To improve asthma prophylaxis, it is important to determine its association with mite allergen exposure in hammocks
Quantum energy flow in mesoscopic dielectric structures
We investigate the phononic energy transport properties of mesoscopic,
suspended dielectric wires. The Landauer formula for the thermal conductance is
derived and its universal aspects discussed. We then determine the variance of
the energy current in the presence of a steady state current flow. In the final
part, some initial results are presented concerning the nature of the
temperature fluctuations of a mesoscopic electron gas thermometer due to the
absorption and emission of wire phonons.Comment: 20 pages, 2 figures. Submitted to Phys. Rev.
Efficient thermoelectric energy conversion on quasi-localized electron states in diameter modulated nanowires
It is known that the thermoelectric efficiency of nanowires increases when their diameter decreases. Recently, we proposed that increase of the thermoelectric efficiency could be achieved by modulating the diameter of the nanowires. We showed that the electron thermoelectric properties depend strongly on the geometry of the diameter modulation. Moreover, it has been shown by another group that the phonon conductivity decreases in nanowires when they are modulated by dots. Here, the thermoelectric efficiency of diameter modulated nanowires is estimated, in the ballistic regime, by taking into account the electron and phonon transmission properties. It is demonstrated that quasi-localized states can be formed that are prosperous for efficient thermoelectric energy conversion
MMT Extremely Metal Poor Galaxy Survey I. An Efficient Technique to Identify Metal Poor Galaxies
We demonstrate a successful strategy for identifying extremely metal poor
galaxies. Our preliminary survey of 24 candidates contains 10 metal poor
galaxies of which 4 have 12+log(O/H)<7.65, some of the lowest metallicity blue
compact galaxies known to date. Interestingly, our sample of metal poor
galaxies have systematically lower metallicity for their luminosity than
comparable samples of blue compact galaxies, dIrrs, and normal star-forming
galaxies. Our metal poor galaxies share very similar properties, however, with
the host galaxies of nearby long-duration gamma-ray bursts (GRBs), including
similar metallicity, stellar ages, and star formation rates. We use H\beta to
measure the number of OB stars present in our galaxies and estimate a
core-collapse supernova rate of ~10^-3 yr^-1. A larger sample of metal poor
galaxies may provide new clues into the environment where GRBs form and may
provide a list of potential GRB hosts.Comment: Accepted to AJ, 8 pages using emulateap
Effective use of personal health records to support emergency services
Smart City systems capture and exchange information with the aim to improve public services. Particularly, healthcare data could help emergency services to plan resources and make life-saving decisions. However, the delivery of healthcare information to emergency bodies must be balanced against the concerns related to citizens’ privacy. Besides, emergency services face challenges in interpreting this data; the heterogeneity of sources and a large amount of information available represent a significant barrier. In this paper, we focus on a case study involving the use of personal health records to support emergency services in the context of a fire building evacuation. We propose a methodology involving a knowledge engineering approach and a common-sense knowledge base to address the problem of deriving useful information from health records and, at the same time, preserve citizens’ privacy. We perform extensive experiments involving a synthetic dataset of health records and a curated gold standard to demonstrate how our approach allows us to identify vulnerable people and interpret their particular needs while avoiding the disclosure of personal information
Diversidad cultural y escenarios migratorios : un estudio sobre formación de profesores
Ante los desafíos que supone enfrentarse con eficacia a las nuevas tareas educativas generadas por la diversidad presente en la actual sociedad abierta, multicultural y en continuo cambio, el enfoque intercultural debe incorporarse en la cualificación del profesorado, a fin de capacitarlo con las competencias que demanda la educación y el desarrollo humano del siglo XXI. El objetivo de esta investigación es analizar la presencia de la interculturalidad en los planes de formación inicial y permanente de los maestros de educación infantil y primaria, y los profesores de educación secundaria de Galicia. Para ello, se han revisado las materias impartidas en los grados para la formación de maestros y los másteres universitarios en Profesorado de Educación Secundaria en las tres universidades gallegas, así como la formación continua ofrecida por el Centro Autonómico de Formación e Innovación. Los resultados ponen de manifiesto una notable carencia formativa en este campo y la necesidad de promover los cambios oportunos en la preparación del profesorado. Finalmente, se formulan algunas propuestas de mejora dirigidas tanto a la administración educativa como a la propia universidad.Davant els reptes que suposa enfrontar-se amb eficàcia a les noves tasques educatives que genera la diversitat present en l'actual societat oberta, multicultural i en continu canvi, l'enfocament intercultural ha de ser incorporat en la qualificació dels professors, per tal de capacitar-los amb les habilitats que demanda l'educació i el desenvolupament humà per al segle xxi. L'objectiu d'aquest estudi és analitzar la presència de la interculturalitat en els plans de formació inicial i permanent dels professors d'educació infantil i primària i els mestres d'educació secundària de Galícia. Amb aquesta finalitat, hem revisat les assignatures impartides en els graus per a la formació de mestres i els màsters universitaris en Professorat d'Educació Secundària de les tres universitats gallegues, així com la formació proporcionada pel Centro Autonómico de Formación e Innovación. Els resultats posen de manifest una notable falta de formació en aquest camp i la necessitat d'impulsar els canvis oportuns en la preparació de professors. Finalment, s'hi formulen algunes propostes de millora tant a l'administració educativa com a la mateixa universitat.Faced with the challenges of coping effectively with the new educational tasks due to the present diversity in today's open, multicultural and continuously evolving society, the intercultural approach has to be incorporated into teacher training in order to provide them with the competences required of education and human development in the 21st century. This study aims to analyze the presence of interculturality in the initial and permanent training programs of childhood, primary and secondary education teachers in Galicia. To this end, the subjects taught in the teacher training degrees and the Master's Degree in Secondary Education of the three Galician universities have been reviewed, as well as the continuing education provided by the Autonomous Center for Training and Innovation. The results show a notable lack of training in this field and the need for timely changes in teacher education. Finally, some proposals for improvement directed at both the educational administration and the university itself are discussed
Control of Dephasing and Phonon Emission in Coupled Quantum Dots
We predict that phonon subband quantization can be detected in the non-linear
electron current through double quantum dot qubits embedded into nano-size
semiconductor slabs, acting as phonon cavities. For particular values of the
dot level splitting , piezo-electric or deformation potential
scattering is either drastically reduced as compared to the bulk case, or
strongly enhanced due to phonon van Hove singularities. By tuning via
gate voltages, one can either control dephasing, or strongly increase emission
into phonon modes with characteristic angular distributions.Comment: 4 pages, 3 figures, accepted for publication as Rapid Comm. in Phys.
Rev.
Simulation of dimensionality effects in thermal transport
The discovery of nanostructures and the development of growth and fabrication
techniques of one- and two-dimensional materials provide the possibility to
probe experimentally heat transport in low-dimensional systems. Nevertheless
measuring the thermal conductivity of these systems is extremely challenging
and subject to large uncertainties, thus hindering the chance for a direct
comparison between experiments and statistical physics models. Atomistic
simulations of realistic nanostructures provide the ideal bridge between
abstract models and experiments. After briefly introducing the state of the art
of heat transport measurement in nanostructures, and numerical techniques to
simulate realistic systems at atomistic level, we review the contribution of
lattice dynamics and molecular dynamics simulation to understanding nanoscale
thermal transport in systems with reduced dimensionality. We focus on the
effect of dimensionality in determining the phononic properties of carbon and
semiconducting nanostructures, specifically considering the cases of carbon
nanotubes, graphene and of silicon nanowires and ultra-thin membranes,
underlying analogies and differences with abstract lattice models.Comment: 30 pages, 21 figures. Review paper, to appear in the Springer Lecture
Notes in Physics volume "Thermal transport in low dimensions: from
statistical physics to nanoscale heat transfer" (S. Lepri ed.
Geo‐Hydromorphological Assessment of Europe’s Southernmost Blanket Bogs
Blanket bogs are a globally rare type of ombrotrophic peatland internationally recognised for long‐term terrestrial carbon storage, the potential to serve as carbon sinks, habitat provision and for their palaeoenvironmental archive. This habitat is protected in the European Union under the Habitats Directive (92/43/EEC), but a number of blanket bogs located in the Cantabrian Mountains (northern Spain), representing the southernmost known edge‐of‐range for this habitat in Europe, are currently not recognised and are at increased threat of loss.
Using climatic data, topography, aerial photography and peat depth surveys, this study has identified ten new areas of blanket bog located between the administrative regions of Cantabria and Castilla y León. Peat depth data and topography were used to provide a detailed geomorphological description and hydromorphological classification (mesotope units) of these currently unrecognised areas of blanket bog.
Maximum peat depth measured across the ten sites ranged from 1.61 m to 3.78 m covering a total area of 18.6 ha of blanket bog (> 40 cm peat depth). The volume of peat accumulated across the sites was determined to be more than 216,000 m3 and is estimated to hold 19.89 ± 3.51kt C. Twenty‐four individual hydrological mesotope units were described indicating a diverse assemblage of blanket bogs in this region.
The peatlands identified in this research extend the known limit of blanket bogs in Europe farther south than previously recorded and combined with four other unprotected blanket bogs recently identified in the Cantabrian Mountains, these peatlands represent 10.5% of blanket bog currently recognised and protected in Spain. The range of anthropogenic pressures currently acting on peatlands in the Cantabrian Mountains indicates that without protection these important landforms and carbon stored may be lost. An urgent update of European peatland inventories is thus required to preserve these valuable carbon stores and potential carbon sinks
Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials
Recent years witnessed a rapid growth of interest of scientific and
engineering communities to thermal properties of materials. Carbon allotropes
and derivatives occupy a unique place in terms of their ability to conduct
heat. The room-temperature thermal conductivity of carbon materials span an
extraordinary large range - of over five orders of magnitude - from the lowest
in amorphous carbons to the highest in graphene and carbon nanotubes. I review
thermal and thermoelectric properties of carbon materials focusing on recent
results for graphene, carbon nanotubes and nanostructured carbon materials with
different degrees of disorder. A special attention is given to the unusual size
dependence of heat conduction in two-dimensional crystals and, specifically, in
graphene. I also describe prospects of applications of graphene and carbon
materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe
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