661 research outputs found

    Comparación del modulo resiliente de la subrasante obtenido a partir de deflexiones de impacto y mediante ensayos de laboratorio en un proyecto vial del departamento de Cundinamarca

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    El presente estudio se llevará a cabo en la carretera El Portal El Antojo que vía une la ciudad de Bogotá, con la carretera Bogotá Villavicencio, esta es de gran importancia porque sirve de apoyo principalmente cuando la Concesión realiza labores de mantenimiento en el túnel de El Boquerón obligando a desviar el tráfico por esta carretera. Para calcular el módulo resiliente de la subrasante en carretera El Portal El Antojo se llevaron a cabo medidas de deflexión en el mes de enero de 2010, mediante el empleo del FWD KUAB 50 2m de la firma GEVIAL LTDA. Para el análisis y procesamiento de la información se llevará a cabo de acuerdo con los lineamientos y normas establecidos en la guía metodológica para la rehabilitación de pavimentos asfálticos de carreteras del INVIAS. Se determinarán parámetros estructurales como la deflexión central, el módulo resiliente de la subrasante, y el número estructural de la vía seleccionada a través de un procedimiento de retro cálcul

    Assessing Child Obesity and Physical Activity in a Hard-to-Reach Population in California's Central Valley, 2012-2013.

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    IntroductionIn California's agricultural Central Valley, the rate of childhood obesity is higher than the national average. Adequate physical activity contributes to obesity prevention and its assessment is useful to evaluate the impact of interventions.MethodsNiños Sanos, Familia Sana (Healthy Children, Healthy Family [NSFS]) uses community-based participatory research to implement an intervention program to reduce childhood obesity among people of Mexican origin in the Central Valley. Anthropometric measurements were conducted on more than 650 children enrolled in NSFS. Physical activity data from a subgroup of children aged 4 to 7 years (n = 134) were collected via a wearable accelerometer.ResultsChildren were classified on the basis of age and sex-adjusted body mass index as healthy weight (57.7%); overweight (19.3%), or obese (23%). Logistic regression showed that moderate to vigorous physical activity (MVPA) was associated with a child's likelihood of having a healthy BMI (odds ratio: 1.03; 95% CI, 1.01-1.05; P = .017).ConclusionNSFS's community-based participatory approach resulted in successful use of a commercial electronic device to measure physical activity quantity and quality in this hard-to-reach population. Promotion of adequate daily MVPA is an appropriate and necessary component of NSFS's childhood obesity prevention strategy

    The Impact of the California Drought on Food Security among Rural Families of Mexican Origin

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    Introduction: The year 2015 marks the fourth year of a drought in California. With no signs of the drought improving, communities in California are left to prioritize their water usage. In the Central Valley, the limited water supply has forced farmers to prioritize on acreage and planting, decisions that trickle down and may impact farmworker families. Objective: The purpose of this study was to explore the impact of a drought in California on family decision-making and coping strategies in the context of broader community changes affecting rural families of Mexican-origin. Methods: This study recruited participants from the Niños Sanos, Familia Sana (NSFS, Healthy Children, Healthy Family) childhood obesity intervention study, conducted from 2011-2015. The primary occupation of two-thirds of the NSFS families was agricultural work. Based on the US Department of Agriculture 18-item food security assessment tool, a baseline household survey among 336 families in 2012 revealed that 45% of the households were food insecure. In 2015, a bilingual graduate student moderated four focus groups in a convenience sample of 26 NSFS families, who were recruited by promotoras (local lay workers). Males and females were assigned to different focus group discussions, each of which lasted 1 ½ hours. Two researchers reviewed transcriptions of the audio recordings and analyzed them for emerging themes. Results/Conclusions: In this Mexican-origin rural population, households headed by less educated mothers, older fathers, and adults engaged in farm work were most vulnerable to food insecurity. The focus groups revealed community changes including out-migration of families, increased food prices, and changes in employment (fewer hours, less predictable, need to travel further to find work). These changes have led families to shift their family decision-making and economize to cope with the unpredictable nature of the agricultural workforce. Paying bills and rent takes priority over food, clothing, medicine and other expenses. All groups mentioned having to deny child requests and family outings. Women noted increased stress on the family and concern about keeping families together. Men expressed the desire to avoid disruption to their children’s lives but were actively considering moving elsewhere. As a community, they have remained united and working together to withstand the challenges the drought has introduced

    Adaptation of a culturally relevant nutrition and physical activity program for low-income, Mexican-origin parents with young children.

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    Latino children experience higher rates of obesity than do non-Latino white children. Family-centered nutrition interventions can slow the rate of weight gain in this population. Niños Sanos, Familia Sana (Healthy Children, Healthy Family) is a 5-year, community-based, participatory research study that targets rural Mexican-origin farmworker families with children aged 2 to 8 years in California's Central Valley. Adaptation of a culturally relevant obesity prevention program involved qualitative research to tailor key obesity prevention messages, pilot testing and implementation of key messages and activities at family nights, and continual modification to incorporate culturally innovative elements. Of the 238 families enrolled, 53% (125) attended the recommended minimum of 5 (of 10 possible) classes during the first year. A university and community partnership can guide development of a culturally tailored obesity prevention program that is suitable for reaching a high-risk Mexican-origin audience through cooperative extension and other public health programs

    Comparison of the VIMOS-VLT Deep Survey with the Munich semi-analytical model. II. The colour-density relation up to z=1.5

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    [Abridged] We perform on galaxy mock catalogues the same colour-density analysis made by Cucciati et al. (2006) on a 5 Mpc/h scale using the VVDS-Deep survey, and compare the results from mocks with observed data. We use mocks with the same flux limits (I=24) as the VVDS (CMOCKS), built using the semi- analytic model by De Lucia & Blaizot (2007) applied to the Millennium Simulation. From CMOCKS, we extracted samples of galaxies mimicking the VVDS observational strategy (OMOCKS). We computed the B-band Luminosity Function LF and the colour-density relation (CDR) in the mocks. We find that the LF in mocks roughly agrees with the observed LF, but at z<0.8 the faint-end slope of the model LF is steeper than the VVDS one. Computing the LF for early and late type galaxies, we show that mocks have an excess of faint early-type and of bright late-type galaxies with respect to data. We find that the CDR in OMOCKS is in excellent agreement with the one in CMOCKS. At z~0.7, the CDR in mocks agrees with the VVDS one (red galaxies reside mainly in high densities). Yet, the strength of the CDR in mocks does not vary within 0.2<z<1.5, while the observed relation flattens with increasing z and possibly inverts at z=1.3. We argue that the lack of evolution in the CDR in mocks is not due only to inaccurate prescriptions for satellite galaxies, but that also the treatment of central galaxies has to be revised. The reversal of the CDR can be explained by wet mergers between young galaxies, producing a starburst event. This should be seen on group scales. A residual of this is found in observations at z=1.5 on larger scales, but not in the mocks, suggesting that the treatment of physical processes affecting satellites and central galaxies in models should be revised.Comment: 15 pages, 12 figures, accepted for publication in A&

    A Sustained Increase in Intracellular Ca2+ Is Required for the Acrosome Reaction in Sea Urchin Sperm

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    AbstractThe acrosome reaction (AR), necessary for fertilization in many species, requires an increase in intracellular Ca2+ ([Ca2+]i). In sea urchin sperm, the AR is triggered by an egg-jelly factor: the associated [Ca2+]i elevation lasts minutes and involves two Ca2+ permeable channels. Both the opening of the second channel and the onset of the AR occur ∼5 s after treatment with egg factor, suggesting that these events are linked. In agreement, removal of Ca2+ from sea water or addition of Ca2+ channel blockers at the time when opening of the second channel is first detected inhibits AR and causes a “rapid” (t1/2 = 3–15 s) decrease in [Ca2+]i and partial inhibition of the intracellular pH change associated with the AR. Simultaneous addition of NH4Cl and either EGTA, Co2+, or Ni2+ 5 s after egg factor prevents the partial inhibition of the evoked pHi change observed but does not reverse AR inhibition. Therefore, the sustained increase in [Ca2+]i caused by the second Ca2+ channel is needed for the sperm AR. Experiments with agents that induce capacitative Ca2+ uptake (thapsigargin and cyclopiazonic acid) suggest that the second channel opened during the AR could be a store-operated Ca2+ channel

    An assessment of the effect of hepatitis B vaccine in decreasing the amount of hepatitis B disease in Italy

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    Abstract Background Hepatitis B (HBV) infection is an important cause of morbidity and mortality and it is associated to a higher risk of chronic evolution in infected children. In Italy the anti-HBV vaccination was introduced in 1991 for newborn and twelve years old children. Our study aims to evaluate time trends of HBV incidence rates in order to provide an assessment of compulsory vaccination health impact. Method Data concerning HBV incidence rates coming from Acute Viral Hepatitis Integrated Epidemiological System (SEIEVA) were collected from 1985 to 2006. SEIEVA is the Italian surveillance national system that registers acute hepatitis cases. Time trends were analysed by joinpoint regression using Joinpoint Regression Program 3.3.1 according to Kim's method. A joinpoint represents the time point when a significant trend change is detected. Time changes are expressed in terms of the Expected Annual Percent Change (EAPC) with 95% confidence interval (95% CI). Results The joinpoint analysis showed statistically significant decreasing trends in all age groups. For the age group 0–14 EAPC was -39.0 (95% CI: -59.3; -8.4), in the period up to 1987, and -12.6 (95% CI: -16.0; -9.2) thereafter. EAPCs were -17.9 (95% CI: -18.7; -17.1) and -6.7 (95% CI: -8.0; -5.4) for 15–24 and ≥25 age groups, respectively. Nevertheless no joinpoints were found for age groups 15–24 and ≥25, whereas a joinpoint at year 1987, before compulsory vaccination, was highlighted in 0–14 age group. No joinpoint was observed after 1991. Discussion Our results suggest that the introduction of compulsory vaccination could have contribute partly in decreasing HBV incidence rates. Compulsory vaccination health impact should be better investigated in future studies to evaluate the need for changes in current vaccination strategy.</p

    Extracellular Vesicles from Healthy Cells Improves Cell Function and Stemness in Premature Senescent Stem Cells by miR-302b and HIF-1α Activation.

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    Aging is accompanied by the accumulation of senescent cells that alter intercellular communication, thereby impairing tissue homeostasis and reducing organ regenerative potential. Recently, the administration of mesenchymal stem cells (MSC)-derived extracellular vesicles has proven to be more effective and less challenging than current stem cell-based therapies. Extracellular vesicles (EVs) contain a cell-specific cargo of proteins, lipids and nucleic acids that are released and taken up by probably all cell types, thereby inducing functional changes via the horizontal transfer of their cargo. Here, we describe the beneficial properties of extracellular vesicles derived from non-senescent MSC, cultured in a low physiological oxygen tension (3%) microenvironment into prematurely senescent MSC, cultured in a hyperoxic ambient (usual oxygen culture conditions, i.e., 21%). We observed that senescent MCS, treated with EVs from non-senescent MCS, showed reduced SA-β-galactosidase activity levels and pluripotency factor (OCT4, SOX2, KLF4 and cMYC, or OSKM) overexpression and increased glycolysis, as well as reduced oxidative phosphorylation (OXPHOS). Moreover, these EVs' cargo induced the upregulation of miR-302b and HIF-1α levels in the target cells. We propose that miR-302b triggered HIF-1α upregulation, which in turn activated different pathways to delay premature senescence, improve stemness and switch energetic metabolism towards glycolysis. Taken together, we suggest that EVs could be a powerful tool to restore altered intercellular communication and improve stem cell function and stemness, thus delaying stem cell exhaustion in aging

    Preventive medicine center and health care for students of medicine and health professions at the Sapienza University of Rome: a research protocol

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    This project aims to develop a Center of Preventive Medicine and Health Care for the students of Medicine and Health profession at Sapienza University of Rome. At the beginning of the university career students, both residents and nonresident s, have to face several difficulties such as: starting smoking or the increase in cigarette consumption ; the independent management of their own health (especially for non residents consequently to the distance of the family doctor) ; unhealthy diet; tuberculosis (TB) biological risk during their university training. These aspects , especially if present at the same time, act as a source stress and adversely affect the quality of life and the academic performance. Specific aims of the project will be: implementing an ambulatory of Preventive Medicine; implementing a virtual ambulatory of general medicine; creating a website on the problems mentioned above. Data collected will be computerized to keep an electronic health record (HER) and to use the information for the purposes of scientific research. The Centre will act in close relationship with the Central Administration, with the Headmasters of the Medical Faculties, and in close collaboration with the Center of Occupational Medicine of Sapienza University
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