794 research outputs found
LAGOVirtual: A Collaborative Environment for the Large Aperture GRB Observatory
We present the LAGOVirtual Project: an ongoing project to develop platform to
collaborate in the Large Aperture GRB Observatory (LAGO). This continental-wide
observatory is devised to detect high energy (around 100 GeV) component of
Gamma Ray Bursts, by using the single particle technique in arrays of Water
Cherenkov Detectors (WCD) at high mountain sites (Chacaltaya, Bolivia, 5300 m
a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m
a.s.l). This platform will allow LAGO collaboration to share data, and computer
resources through its different sites. This environment has the possibility to
generate synthetic data by simulating the showers through AIRES application and
to store/preserve distributed data files collected by the WCD at the LAGO
sites. The present article concerns the implementation of a prototype of
LAGO-DR adapting DSpace, with a hierarchical structure (i.e. country,
institution, followed by collections that contain the metadata and data files),
for the captured/simulated data. This structure was generated by using the
community, sub-community, collection, item model; available at the DSpace
software. Each member institution-country of the project has the appropriate
permissions on the system to publish information (descriptive metadata and
associated data files). The platform can also associate multiple files to each
item of data (data from the instruments, graphics, postprocessed-data, etc.).Comment: Second EELA-2 Conference Choroni, Venezuela, November 25th to 27th
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BIODIESEL FROM MICROALGAE: THE EFFECT OF FUEL PROPERTIES ON POLLUTANT EMISSIONS
Recently, biofuels have been presented as a viable alternative for the main challenges of the energy industry: the depleting supplies of petroleum and the global warming due to greenhouse effect. Biofuels may be produced from several different feedstocks, such as sugarcane, animal fat, oil crops or even microalgae. Replacing conventional petroleum sourced fuels with biofuels may significantly reduce global greenhouse effect gases emission when considering the life cycle of such fuels. Even with this advantage, biofuels present new challenges concerning the engine adaptation and the pollutant emissions. In this context, this paper aims to clarify the relation between fuel properties of microalgae biodiesel and pollutant emissions, studying which properties are desirable in these new fuels to guarantee engine operation without degradation of performance in comparison to conventional diesel
Test de Zohlen y su relación con el ángulo Q en población sin dolor patelofemoral
ResumenObjetivoDeterminar qué porcentaje de una población sin dolor anterior de rodilla tiene un test de Zohlen positivo, además determinar el ángulo Q de esta población y buscar si existe alguna relación entre la positividad del test de Zohlen y alteraciones en el ángulo Q.Material y métodoEstudio descriptivo-prospectivo observacional. Aplicación del test de Zohlen y medición del ángulo Q. La población se dividió en 2 grupos: test de Zohlen positivo y test de Zohlen negativo. Cuantificación y comparación de medias del ángulo Q en los dos grupos.Resultados90 sujetos evaluados, promedio de edad 20,18 años (18-40). Veinte sujetos (22,2%) con test de Zohlen positivo. Ángulo Q promedio en los sujetos con test de Zohlen negativo: 14,95°; ángulo Q promedio en los sujetos con test de Zohlen positivo: 16,9° (p < 0,05).Ángulo Q promedio en hombres con test de Zohlen negativo13,4°; ángulo Q promedio en hombres con test de Zohlen positivo: 16° (p < 0,05). Ángulo Q promedio en mujeres con test de Zohlen negativo: 16,5°; ángulo Q promedio en mujeres con test de Zohlen positivo: 18°, sin diferencias estadísticamente significativas entre ambos grupos.ConclusionesEl test de Zohlen tiene una correlación positiva con el ángulo Q en sujetos de sexo masculino. Dada la correlación entre un ángulo Q alterado y la presencia de dolor anterior de rodilla, en los pacientes que presentan un test de Zohlen positivo sin haber consultado por dolor anterior de rodilla, la prevención primaria de dolor anterior de rodilla puede ser de utilidad.AbstractObjectiveTo determine the percentage of a population without anterior knee pain with a positive Zohlen test, and also to determine the Q angle of this population and to determine if there is any relationship between the Zohlen test and Q angle anomalies.MethodsA prospective observational study was conducted in which Zohleńs test was applied and the Q angle was measured. The population was divided into 2 groups: Zohleńs positive and Zohleńs negative. Q angle was compared in the 2 groups.ResultsThe study included 90 subjects, with a mean age 20.18 years (18-40), of whom 20 subjects (22.2%) had positive Zohleńs test. The mean Q angle in subjects with negative Zohleńs test was 14.95°, and the mean Q angle in subjects with positive Zohleńs test was 16,9° (p<.05). The mean Q angle in men with negative Zohleńs test was 13.4°, and the mean Q angle in men with positive Zohleńs test was 16° (p < .05). The mean Q angle in women with negative Zohleńs test was 16.5°, with a mean Q angle of 18° in women with positive Zohleńs test, with no statistically significant differences found between groups.ConclusionsZohleńs test has a positive correlation with the Q angle in male subjects. Given the correlation between the Q angle and the presence of anterior knee pain in patients who have a positive test without symptoms, primary prevention of anterior knee pain can be achieved
A Preliminary Study to Understand How Mainstream Accessibility and Digital Assistive Technologies Reaches People in Lower- and Middle-Income Countries
Accessibility to mainstream digital devices and the use of Digital Assistive Technologies (Digital AT) facilitates participation and improves function and independece of people with disabilities in these regions. However, mainstream access is not fully realised in LMICs and there are multiple barriers in the way for the uptake and use of Digital AT. Through a thematic analysis of interviews with eight expert professionals in the domain of provisioning Digital AT and its related services in LMICs, we discuss five steps or barriers for the uptake and use of Digital AT and have identified three practical strategies that have shown evidence to overcome these barriers. Developers of Digital AT will find these insights useful and the same will provide an understanding of the market to business strategists to deliver pathways to better accessibility services and new Digital AT
Alfalfa grazing increases vitamin E content and improves fatty acid profile in L. dorsi from light lambs
Polyunsaturated fatty acid biosynthesis is involved in phenylephrine-mediated calcium release in vascular smooth muscle cells
Stimulation of vascular smooth muscle (VSM) ?1-adrenoceptors induces myosin phosphorylation and vasoconstriction via mobilisation of intracellular calcium and production of specific eicosanoids. Polyunsaturated fatty acid (PUFA) biosynthesis in VSM cells is involved, although the precise mechanism is not known. To address this, we characterised PUFA biosynthesis in VSM cells and determined its role in intracellular calcium release and eicosanoid production. Murine VSM cells converted 18:2n-6 to longer chain PUFA including 22:5n-6. ?6 (D6d) and ?5 (D5d) desaturase, and elongase (Elovl) 5 were expressed. Elovl2 was not detected in human, mouse or rat VSM cells, or in rat or mouse aortae, but tit was not associated with hypermethylation of its promoter. D6d or D5d inhibition reduced 18:3n-6 and 20:4n-6 synthesis, respectively, and induced concentration-related decrease in phenylephrine-mediated calcium release, and in PGE2 and PGF2? secretion. Together these findings suggest that PUFA biosynthesis in VSM cells is involved in calcium release associated with vasoconstriction
Prenatal development is linked to bronchial reactivity: epidemiological and animal model evidence
Chronic cardiorespiratory disease is associated with low birthweight suggesting the importance of the developmental environment. Prenatal factors affecting fetal growth are believed important, but the underlying mechanisms are unknown. The influence of developmental programming on bronchial hyperreactivity is investigated in an animal model and evidence for comparable associations is sought in humans. Pregnant Wistar rats were fed either control or protein-restricted diets throughout pregnancy. Bronchoconstrictor responses were recorded from offspring bronchial segments. Morphometric analysis of paraffin-embedded lung sections was conducted. In a human mother-child cohort ultrasound measurements of fetal growth were related to bronchial hyperreactivity, measured at age six years using methacholine. Protein-restricted rats' offspring demonstrated greater bronchoconstriction than controls. Airway structure was not altered. Children with lesser abdominal circumference growth during 11-19 weeks' gestation had greater bronchial hyperreactivity than those with more rapid abdominal growth. Imbalanced maternal nutrition during pregnancy results in offspring bronchial hyperreactivity. Prenatal environmental influences might play a comparable role in humans
Socioeconomic inequalities and the equity impact of population-level interventions for adolescent health: an overview of systematic reviews
Objectives: Despite robust evidence on health inequalities in adulthood, less attention has been paid to inequalities in adolescence. The aim of this overview was to examine systematic review (SR) evidence on the equity impact of population-level interventions intended to improve health, happiness and wellbeing for adolescents. Study Design: An overview (review of systematic reviews). Methods: Eleven electronic databases were systematically searched to identify SRs of population-level interventions for adolescent health. A secondary data analysis of socioeconomic inequality was conducted to identify whether SRs reported on primary studies in terms of disadvantage, by measures of socioeconomic status (SES) and by differential effects. Results: 35,310 review titles were screened; 566 full texts were retrieved and 140 SRs met the predefined selection criteria. Differential intervention effects were considered in 42/140 (30%) SRs, 18/140 (13%) reported primary studies using an SES measure and 16/140 (11%) explicitly reported differential effects. 15/140 SRs (11%) explicitly focused on socioeconomic inequalities; of these 4/15 reported differential intervention effects in more detail, 7/15 concluded there was insufficient primary evidence to identify the impact of interventions on socioeconomic inequalities and 4/15 planned to examine differential effects by SES, but this was not reported further. Conclusions: Our overview identifies that there is limited SR evidence on the equity impact of population-level interventions for adolescent health. Strengthening the evidence on whether interventions narrow or widen inequalities for adolescents must be a priority for public health research
Cerebroespinal fluid control of neurogenesis induced by retinoic acid during early brain development
Producción CientíficaEmbryonic-cerebrospinal fluid (E-CSF) plays crucial roles in early brain development including the control
of neurogenesis. Although FGF2 and lipoproteins present in the E-CSF have previously been shown
to be involved in neurogenesis, the main factor triggering this process remains unknown. E-CSF contains
all-trans-retinol and retinol-binding protein involved in the synthesis of retinoic acid (RA), a neurogenesis
inducer. In early chick embryo brain, only the mesencephalic-rombencephalic isthmus (IsO) is able to
synthesize RA. Here we show that in chick embryo brain development: (1) E-CSF helps to control RA synthesis
in the IsO by means of the RBP and all-trans-retinol it contains; (2) E-CSF has retinoic acid activity,
which suggests it may act as a diffusion pathway for RA; and (3) the influence of E-CSF on embryonic
brain neurogenesis is to a large extent due to its involvement in RA synthesis. These data help to
understand neurogenesis from neural progenitor cells2015-05-2
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