159 research outputs found

    Sinóptico de una danza

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    Fabricación de alcohol etílico para carburante por sacarificación de la madera

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    Latin American Economic Integration

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    Irrigation efficiency and water-policy implications for river basin resilience

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    Rising demand for food, fiber, and biofuels drives expanding irrigation withdrawals from surface water and groundwater. Irrigation efficiency and water savings have become watchwords in response to climate-induced hydrological variability, increasing freshwater demand for other uses including ecosystem water needs, and low economic productivity of irrigation compared to most other uses. We identify three classes of unintended consequences, presented here as paradoxes. Ever-tighter cycling of water has been shown to increase resource use, an example of the <i>efficiency paradox</i>. In the absence of effective policy to constrain irrigated-area expansion using "saved water", efficiency can aggravate scarcity, deteriorate resource quality, and impair river basin resilience through loss of flexibility and redundancy. Water scarcity and salinity effects in the lower reaches of basins (symptomatic of the <i>scale paradox</i>) may partly be offset over the short-term through groundwater pumping or increasing surface water storage capacity. However, declining ecological flows and increasing salinity have important implications for riparian and estuarine ecosystems and for non-irrigation human uses of water including urban supply and energy generation, examples of the <i>sectoral paradox</i>. This paper briefly considers three regional contexts with broadly similar climatic and water-resource conditions – central Chile, southwestern US, and south-central Spain – where irrigation efficiency directly influences basin resilience. The comparison leads to more generic insights on water policy in relation to irrigation efficiency and emerging or overdue needs for environmental protection

    Norovirus Infection and Disease in an Ecuadorian Birth Cohort: Association of Certain Norovirus Genotypes With Host FUT2 Secretor Status.

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    BACKGROUND: Although norovirus is the most common cause of gastroenteritis, there are few data on the community incidence of infection/disease or the patterns of acquired immunity or innate resistance to norovirus. METHODS: We followed a community-based birth cohort of 194 children in Ecuador with the aim to estimate (1) the incidence of norovirus gastroenteritis from birth to age 3 years, (2) the protective effect of norovirus infection against subsequent infection/disease, and (3) the association of infection and disease with FUT2 secretor status. RESULTS: Over the 3-year period, we detected a mean of 2.26 diarrheal episodes per child (range, 0-12 episodes). Norovirus was detected in 260 samples (18%) but was not found more frequently in diarrheal samples (79 of 438 [18%]), compared with diarrhea-free samples (181 of 1016 [18%]; P = .919). A total of 66% of children had at least 1 norovirus infection during the first 3 years of life, and 40% of children had 2 infections. Previous norovirus infections were not associated with the risk of subsequent infection. All genogroup II, genotype 4 (GII.4) infections were among secretor-positive children (P < .001), but higher rates of non-GII.4 infections were found in secretor-negative children (relative risk, 0.56; P = .029). CONCLUSIONS: GII.4 infections were uniquely detected in secretor-positive children, while non-GII.4 infections were more often found in secretor-negative children

    Excavation at Aguas Buenas, Robinson Crusoe Island, Chile, of a gunpowder magazine and the supposed campsite of Alexander Selkirk, together with an account of early navigational dividers

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    Excavations were undertaken of a ruined building at Aguas Buenas, identified as an 18th-century Spanish gunpowder magazine. Evidence was also found for the campsite of an early European occupant of the island. A case is made that this was Alexander Selkirk, a castaway here from 1704 to 1709. Selkirk was the model for Defoe’s Robinson Crusoe. A detailed discussion is given of a fragment of copper alloy identifi ed as being from a pair of navigational dividers

    Vasoactive intestinal peptide gene polymorphisms, associated with its serum levels, predict treatment requirements in early rheumatoid arthritis

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    We previously reported that early arthritis (EA) patients with low vasoactive intestinal peptide (VIP) serum levels demonstrate a worse clinical disease course. In this study, we analysed whether variants in the VIP gene correlated with its serum levels and clinical EA parameters. The VIP gene was sequenced in patients with extremely high/low VIP levels, measured by enzyme immunoassay. Sixteen single nucleotide polymorphisms (SNPs) were diferentially distributed between both groups, which were subsequently genotyped in two patients’ sets. We observed that patients with rs688136 CC genotype showed higher VIP levels in both discovery (n=91; p=0.033) and validation populations (n=131; p=0.007). This efect was attenuated by the presence of minor alleles rs35643203 and rs12201140, which showed a clear trend towards low VIP level association (p=0.118 and p=0.049, respectively). Functional studies with miR-205-5p, which has a target site in the 3′ UTR close to rs688136, revealed a miRNA-mediated regulatory mechanism explaining the higher VIP gene expression in homozygous patients. Moreover, patients with an rs688136 CC genotype and no minor alleles of the other polymorphisms required less treatment (p=0.009). We concluded that the identifcation of polymorphisms associated with VIP serum levels would complement the clinical assessment of the disease severity in rheumatoid arthritis patients

    Demographic parameters in the population of dogs and cats in human settlements of the district of Ventanilla, Callao-Peru

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    El estudio tuvo como objetivo determinar indicadores demográficos de la población de canes y gatos domésticos con dueño en asentamientos humanos del distrito de Ventanilla, Callao (Perú). Se realizó un muestreo por conglomerado para seleccionar los grupos poblacionales y un muestreo estratificado y sistemático para seleccionar las viviendas. La información fue recolectada mediante una encuesta. Se calcularon las características demográficas de la tenencia de canes y gatos, y la relación can:persona y gato:persona. El 61.9 y 40.0% de las viviendas poseían canes y gatos, respectivamente. El número de mascotas por vivienda fue de 1.8 para ambas especies. El número de crías en los canes fue de 4.3 y en gatos de 3.1. La tasa de supervivencia estimada de las crías fue de 56.2 ± 3.0% en canes y de 66.4 ± 3.9% en gatos. La esperanza de vida estimada fue de 4.21 ± 0.44 años en canes y de 2.64 ± 0.46 años en gatos. Se estimó que existía 1 can por cada 3.98 personas y 1 gato por cada 5.34 personas. El 23% de encuestados manifestó mantener canes vagabundos en el exterior de las viviendas. Se espera que la información ofrecida sirva a las autoridades de salud para planificar programas de control poblacional y tenencia responsable de animales de compañía en esta población.The study aimed to determine demographic indicators of the population of domestic dogs and cats with owner in human settlements in the district of Ventanilla, Callao (Peru). A cluster sampling was performed to select the population groups and a stratified and systematic sampling was used to select the dwellings. The information was collected through a survey. The demographic characteristics of dogs and cats, and the relation dog:person and cat:person was calculated. In total, 61.9 and 40.0% of the houses owned dogs and cats, respectively. The number of pets per household was 1.8 in both species. The number of offspring in dogs was 4.3 and in cats was 3.1. The estimated survival rate was 56.2 ± 3.0% for puppies and 66.4 ± 3.9% for kittens. The estimated life expectancy was 4.21 ± 0.44 years in dogs and 2.64 ± 0.46 years in cats. It was estimated that there were 1 dog per 3.98 persons and 1 cat per 5.34 persons. Twenty-three percent of respondents said they maintained stray dogs outside homes. It is expected that the information provided will serve health authorities to plan population control programs and responsible pet ownership in this population

    Yaws elimination in Ecuador: Findings of a serological survey of children in Esmeraldas province to evaluate interruption of transmission.

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    BACKGROUND: The WHO roadmap for neglected tropical diseases includes yaws eradication requiring certification of elimination of transmission in all endemic and formerly endemic countries worldwide. A community-based programme for yaws control was considered to have achieved elimination of the infection in the endemic focus in Ecuador after 1993. We did a serosurvey of children in this focus to provide evidence for interruption of transmission. METHODS: Survey of serum samples collected from children aged 2 to 15 years living in the formerly endemic and in geographically contiguous areas. A convenience sample of sera collected between 2005 were 2017 from non-yaws studies, were analyzed using immunochromatic rapid tests to screen (OnSite Syphilis Ab Combo Rapid Test) for Treponema pallidum-specific antibodies and confirm (DPP Syphilis Screen and Confirm) seroreactivity based on the presence antibodies to treponemal and non-treponemal antigens. RESULTS: Seroreactivity was confirmed in 6 (0.14%, 95% CI 0.06-0.30) of 4,432 sera analyzed and was similar in formerly endemic (0.11%, (95% CI 0.01-0.75) and non-endemic (0.14%, 95% CI 0.06-0.34) communities. All seroreactors were of Afro-Ecuadorian ethnicity and most were male (4/6) and aged 10 or more years (5/6), the latter possibly indicating venereal syphilis. Only 1 seroreactor lived in a community in the Rio Santiago, that was formerly hyperendemic for yaws. CONCLUSION: We observed very low levels of treponemal transmission in both formerly endemic and non-endemic communities which might be indicative of congenital or venereal syphilis and, if yaws, would likely be insufficient to maintain transmission of this endemic childhood infection. Additional surveys of children aged 1 to 5 years are planned in Rio Santiago communities to exclude yaws transmission
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