1,791 research outputs found
A catalogue of accurate wavelengths in the optical spectrum of the Sun
We present accurate measurements of the central wavelengths of 4947 atomic
absorption lines in the solar optical spectrum. The wavelengths, precise to a
level ~ 50-150 m/s, are given for both flux and disc-centre spectra, as
measured in relatively recent FTS solar atlases. This catalogue modernizes
existing sources based on photographic measurements and provides a benchmark to
test and perform wavelength calibrations of astronomical spectra. It will also
permit observers to improve the absolute wavelength calibration of solar
optical spectra when lamps are not available at the telescope.Comment: 3 pages, 1 ASCII table (4947 records, download the source to view);
uses aa.cls (included); accepted for publication in A&A
Complementarity between human capital and trade in regional technological progress
The effect of openness and trade orientation on economic growth remains a highly contentious issue. Trade facilitates knowledge diffusion and the adoption of more advanced and efficient technologies which faster total factor productivity (TFP) growth and, hence, per capita income. New technologies that diffuse by trade require a sufficiently qualified labour force to adapt them into the domestic productive environment. Thus, openness and human capital accumulation will lead to TFP growth, and the larger the complementarity between both variables the higher TFP growth. The paper discusses the implications of these assumptions and tests their empirical validity using a pool of data for the industrial sector in the Spanish regions in a period in which both the stock of human capital and openness experienced a not able improvement. Key words: trade, human capital, technological progress and regions. JEL category: C23, D24, O33.
Complementarity between human capital and trade in regional technological progress
The effect of openness and trade orientation on economic growth remains a highly contentious issue in the literature. Trade facilitates the spread of knowledge and the adoption of more advanced and efficient technologies, which hastens total factor productivity (TFP) growth and, hence, per capita income. New technologies that spread through trade require a sufficiently skilled labour force to adapt them to the domestic productive environment. Thus, openness and human capital accumulation will lead to TFP growth and the greater the complementarity between both variables, the higher the TFP growth. This paper discusses the implications of these assumptions and tests their empirical validity, using a pool of data for manufacturing industry in Spanish regions in a period in which both the stock of human capital and openness experienced a notable increase.technological progress, industry, human capital, trade
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Detection of enteric parasite DNA in household and bed dust samples: potential for infection transmission.
BACKGROUND: Enteric parasites are transmitted in households but few studies have sampled inside households for parasites and none have used sensitive molecular methods. METHODS: We collected bed and living room dust samples from households of children participating in a clinical trial of anthelmintic treatment in rural coastal Ecuador. Dust was examined for presence of DNA specific for 11 enteric parasites (Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Toxocara canis and T. cati, Giardia lamblia, Blastocystis hominis, Cryptosporidium spp., and Entamoeba histolytica) by quantitative PCR (qPCR). RESULTS: Of the 38 households sampled, 37 had positive dust for at least one parasite and up to 8 parasites were detected in single samples. Positivity was greatest for B. hominis (79% of household samples) indicating a high level of environmental fecal contamination. Dust positivity rates for individual pathogens were: S. stercoralis (52%), A. lumbricoides (39%), G. lamblia (39%), Toxocara spp. (42%), hookworm (18%) and T. trichiura (8%). DNA for Cryptosporidium spp. and E. histolytica was not detected. Bed dust was more frequently positive than floor samples for all parasites detected. Positivity for A. lumbricoides DNA in bed (adjusted OR: 10.0, 95% CI: 2.0-50.1) but not floor dust (adjusted OR: 3.6, 95% CI: 0.3-37.9) was significantly associated with active infections in children. CONCLUSIONS: To our knowledge, this is the first use of qPCR on environmental samples to detect a wide range of enteric pathogen DNA. Our results indicate widespread contamination of households with parasite DNA and raise the possibility that beds, under conditions of overcrowding in a humid tropical setting, may be a source of transmission
CaracterizaciĂłn economica del municipio de Rionegro, Antioquia, 2004-2006
Este trabajo caracteriza la actividad econĂłmica del Municipio de Rionegro (Antioquia) en el perĂodo 2004-2006. A partir del anĂĄlisis de la evoluciĂłn de su estructura productiva, las dinĂĄmicas recientes en los principales sectores econĂłmicos y las caracterĂsticas de su mercado laboral; todo enmarcado en el contexto del desempeño reciente de la economĂa del Oriente antioqueño. El dinamismo econĂłmico de esta regiĂłn ha tenido especial relevancia en el municipio de Rionegro como resultado, entre otros factores, del abastecimiento de productos agrĂcolas y materias primas para el Ărea Metropolitana del Valle de AburrĂĄ, del acelerado desarrollo urbano y turĂstico, de su infraestructura vial, de servicios y, telecomunicaciones de carĂĄcter departamental y nacional y por los servicios hoteleros de alta calidad. Rionegro es considerado eje central de la subregiĂłn, por su aparato productivo y laboral que le han permitido apalancar el desarrollo socioeconĂłmico de la zona y servir como modelo y referente en sus prĂĄcticas administrativas.Oriente Antioqueño - condiciones economicas, Rionegro (Antioquia) - aspectos economicos, Mercado laboral - Rionegro (Antioquia)
Health inequity in workers of Latin America and the Caribbean
Latin America and the Caribbean (LAC) is the worldâs most inequitable region in terms of wealth distribution. The full scale of social inequalities in health has been hidden by the lack of reliable data. This study aimed to measure and compare health inequalities in the working population within and between 15 countries of LAC
Productivity and Seasonality Drive Total Soil Respiration in Semi-Arid Juniper Woodlands (Juniperus thurifera L., Southern Spain)
We analyzed the relationship between forest productivity (joint effect of forest maturity and soil quality) and total soil respiration (mu mol CO2 m(-2) s(-1)) in semi-arid juniper woodlands (young woodlands growing in abandoned farmlands with deeper soils, and mature woodlands in lithic soils), and investigated the seasonal variation in soil CO2 efflux as a function of soil temperature and the soil water content. We measured the soil CO2 efflux from twelve cylinders in the soil over a three-year period using LI-6400 equipment. The results show that, in the more productive site (young woodland), soil CO2 efflux was higher due to greater respiration, mainly in the driest periods. Soil respiration followed a seasonal trend, being higher in spring and decreasing in cold periods. In both juniper woodlands and especially in the older forest, the CO2 efflux rates were low ( 25%) for both woodlands, coinciding with warm temperatures in the spring. This period also corresponded to the highest CO2 efflux recorded in both woodlands. The accumulation of organic C seems to also be important to maintain elevated soil respiration in summer, especially in young woodlands. Thus, apart from microclimatic conditions, factors related to productivity regulate respiratory activity
Osteoarthritis:Mechanistic Insights, Senescence, and Novel Therapeutic Opportunities
Osteoarthritis (OA) is the most common joint disease. In the last years, the research community has focused on understanding the molecular mechanisms that led to the pathogenesis of the disease, trying to identify different molecular and clinical phenotypes along with the discovery of new therapeutic opportunities. Different types of cell-to-cell communication mechanisms have been proposed to contribute to OA progression, including mechanisms mediated by connexin43 (Cx43) channels or by small extracellular vesicles. Furthermore, changes in the chondrocyte phenotype such as cellular senescence have been proposed as new contributors of the OA progression, changing the paradigm of the disease. The use of different drugs able to restore chondrocyte phenotype, to reduce cellular senescence and senescence-associated secretory phenotype components, and to modulate ion channel activity or Cx43 appears to be promising therapeutic strategies for the different types of OA. In this review, we aim to summarize the current knowledge in OA phenotypes related with aging and tissue damage and the new therapeutic opportunities currently available
Long-term exhaustion of the inbreeding load in Drosophila melanogaster
Inbreeding depression, the decline in fitness of inbred individuals, is a ubiquitous phenomenon of great relevance in evolutionary biology and in the fields of animal and plant breeding and conservation. Inbreeding depression is due to the expression of recessive deleterious alleles that are concealed in heterozygous state in noninbred individuals, the so-called inbreeding load. Genetic purging reduces inbreeding depression by removing these alleles when expressed in homozygosis due to inbreeding. It is generally thought that fast inbreeding (such as that generated by full-sib mating lines) removes only highly deleterious recessive alleles, while slow inbreeding can also remove mildly deleterious ones. However, a question remains regarding which proportion of the inbreeding load can be removed by purging under slow inbreeding in moderately large populations. We report results of two long-term slow inbreeding Drosophila experiments (125â234 generations), each using a large population and a number of derived lines with effective sizes about 1000 and 50, respectively. The inbreeding load was virtually exhausted after more than one hundred generations in large populations and between a few tens and over one hundred generations in the lines. This result is not expected from genetic drift alone, and is in agreement with the theoretical purging predictions. Computer simulations suggest that these results are consistent with a model of relatively few deleterious mutations of large homozygous effects and partially recessive gene action
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