1,626 research outputs found

    The Effect of Conservation Agriculture and Environmental Factors on CO2 Emissions in a Rainfed Crop Rotation

    Get PDF
    There are many factors involved in the release of CO2 emissions from the soil, such as the type of soil management, the soil organic matter, the soil temperature and moisture conditions, crop phenological stage, weather conditions, residue management, among others. This study aimed to analyse the influence of these factors and their interactions to determine the emissions by evaluating the environmental cost expressed as the kg of CO2 emitted per kg of production in each of the crops and seasons studied. For this purpose, a field trial was conducted on a farm in Seville (Spain). The study compared Conservation Agriculture, including its three principles (no-tillage, permanent soil cover, and crop rotations), with conventional tillage. Carbon dioxide emissions measured across the four seasons of the experiment showed an increase strongly influenced by rainfall during the vegetative period, in both soil management systems. The results of this study confirm that extreme events of precipitation away from the normal means, result in episodes of high CO2 emissions into the atmosphere. This is very important because one of the consequences for future scenarios of climate change is precisely the increase of extreme episodes of precipitation and periods extremely dry, depending on the area considered. The total of emission values of the different plots of the study show how the soils under the conventional system (tillage) have been emitting 67% more than soils under the conventional agriculture system during the 2010/11 campaign and 25% for the last campaign where the most appreciable differences are observed

    Validation of metabolic syndrome using medical records in the SUN cohort

    Get PDF
    The objective of this study was to evaluate the validity of self reported criteria of Metabolic Syndrome (MS) in the SUN (Seguimiento Universidad de Navarra) cohort using their medical records as the gold standard. METHODS: We selected 336 participants and we obtained MS related data according to Adult Treatment Panel III (ATP III) and International Diabetes Federation (IDF). Then we compared information on the self reported diagnosis of MS and MS diagnosed in their medical records. We calculated the proportion of confirmed MS, the proportion of confirmed non-MS and the intraclass correlation coefficients for each component of the MS. RESULTS: From those 336 selected participants, we obtained sufficient data in 172 participants to confirm or reject MS using ATP III criteria. The proportion of confirmed MS was 91.2% (95% CI: 80.7- 97.1) and the proportion of confirmed non-MS was 92.2% (95% CI: 85.7-96.4) using ATP III criteria. The proportion of confirmed MS using IDF criteria was 100% (95% CI: 87.2-100) and the proportion of confirmed non-MS was 97.1% (95% CI: 85.1-99.9). Kappa Index was 0.82 in the group diagnosed by ATP III criteria and 0.97 in the group diagnosed by IDF criteria. Intraclass correlation coefficients for the different component of MS were: 0.93 (IC 95%:0.91- 0.95) for BMI; 0.96 (IC 95%: 0.93-0.98) for waist circumference; 0.75 (IC 95%: 0.66-0.82) for fasting glucose; 0.50 (IC 95%:0.35-0.639) for HDL cholesterol; 0.78 (IC 95%: 0.70-0.84) for triglycerides; 0.49 (IC 95%:0.34-0.61) for systolic blood pressure and 0.55 (IC 95%: 0.41-0.65) for diastolic blood pressure. CONCLUSIONS: Self-reported MS based on self reported components of the SM in a Spanish cohort of university graduates was sufficiently valid as to be used in epidemiological studies

    Limits on Associated Production of Visibly and Invisibly Decaying Higgs Bosons from Z Decays

    Get PDF
    Many extensions of the standard electroweak model Higgs sector suggest that the main Higgs decay channel is "invisible", for example, hJJh \to J J where JJ denotes the majoron, a weakly interacting pseudoscalar Goldstone boson associated to the spontaneous violation of lepton number. In many of these models the Higgs boson may also be produced in association to a massive pseudoscalar boson (HA), in addition to the standard Bjorken mechanism (HZ). We describe a general strategy to determine limits from LEP data on the masses and couplings of such Higgs bosons, using the existing data on acoplanar dijet events as well as data on four and six bb jet event topologies. For the sake of illustration, we present constraints that can be obtained for the ALEPH data.Comment: FTUV/94-36, IFIC/94-31 TIFR/TH/94--25, 12 pages + 4 figures (included as ps files at the end

    Magnetic Nanoparticles for Power Absorption: optimizing size, shape and magnetic properties

    Get PDF
    We present a study on the magnetic properties of naked and silica-coated Fe3O4 nanoparticles with sizes between 5 and 110 nm. Their efficiency as heating agents was assessed through specific power absorption (SPA) measurements as a function of particle size and shape. The results show a strong dependence of the SPA with the particle size, with a maximum around 30 nm, as expected for a Neel relaxation mechanism in single-domain particles. The SiO2 shell thickness was found to play an important role in the SPA mechanism by hindering the heat outflow, thus decreasing the heating efficiency. It is concluded that a compromise between good heating efficiency and surface functionality for biomedical purposes can be attained by making the SiO2 functional coating as thin as possible.Comment: 15 pages, 7 figures, 2 table

    A Mediterranean lifestyle reduces the risk of cardiovascular disease in the “Seguimiento Universidad de Navarra” (SUN) cohort

    Get PDF
    Background and aims: A healthy lifestyle is essential to prevent cardiovascular disease (CVD). However, beyond dietary habits, there is a scarcity of studies comprehensively assessing the typical traditional Mediterranean lifestyle with a multi-dimensional index. We assessed the association between the Mediterranean lifestyle (measured with the MEDLIFE index including diet, physical activity, and other lifestyle factors) and the incidence of CVD. Methods and results: The “Seguimiento Universidad de Navarra” (SUN) project is a prospective, dynamic and multipurpose cohort of Spanish university graduates. We calculated a MEDLIFE score, composed of 28 items on food consumption, dietary habits, physical activity, rest, social habits, and conviviality, for 18,631 participants by assigning 1 point for each typical Mediterra- nean lifestyle factor achieved, for a theoretically possible final score ranging from 0 to 28 points. During an average follow-up of 11.5 years, 172 CVD cases (myocardial infarction, stroke or cardio- vascular death) were observed. An inverse association between the MEDLIFE score and the risk of primary cardiovascular events was observed, with multivariable-adjusted hazard ratio (HR) Z 0.50; (95% confidence interval, 0.31e0.81) for the highest MEDLIFE scores (14e23 points) compared to the lowest scores (0e9 points), p (trend) Z 0.004. Conclusion: A higher level of adherence to the Mediterranean lifestyle was significantly associ- ated with a lower risk of CVD in a Spanish cohort. Public health strategies should promote the Mediterranean lifestyle to preserve cardiovascular health

    Tecnologías de materiales con aplicaciones en fusión y su desarrollo en la instalación TechnoFusión

    Full text link
    El futuro Centro Nacional de Tecnologías para la Fusión, TechnoFusión, tiene como objetivo desarrollar aquellas tecnologías, relacionadas con materiales, metales líquidos, manipulación remota y simulación, que permitan avanzar en los actuales retos que supone el uso de la fusión nuclear. Sus instalaciones, abiertas al servicio de la comunidad científica externa, garantizarán una destacada participación de empresas y grupos de investigación españoles. En esta contribución se describirán y analizarán las instalaciones que TechnoFusión construirá con capacidad para abordar: la fabricación y procesado de nuevas aleaciones a escala semiindustrial; el comportamiento de materiales, simulando las condiciones durante operación mediante una instalación de triple irradiación (iones pesados, hidrógeno y helio), generadores de plasma lineal (continuo y pulsado) y un circuito de litio líquido; y la caracterización del efecto que las severas condiciones de experimentación producen en las propiedades, en la composición y en la microestructura de materiales estructurales y funcionales (técnicas convencionales e in-situ)

    Prospective study of changes in sugar-sweetened beverages consumption and incidence of metabolic syndrome and its components

    Get PDF
    The incidence of the metabolic syndrome (MetS) is increasing and lifestyle behaviours may play a role. The aim of the present study was to prospectively assess the association between changes in the consumption of sugar-sweetened beverages (SSB) and the incidence of the MetS and its components in a Spanish cohort of university graduates. We included 8157 participants initially free of the MetS and followed up during at least 6 years. SSB consumption was collected by a FFQ previously validated in Spain. The change in SSB consumption was calculated as the difference between SSB consumption at a 6-year follow-up and baseline consumption. The MetS was defined according to the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute's new definition of the MetS that had harmonised previous definitions. The associations between changes in SSB intake and the MetS were examined using multiple logistic regression. We observed 361 incident cases of the MetS. Participants who increased their consumption of SSB (upper v. lower quintile) had a significantly higher risk of developing the MetS (adjusted OR 2·2, 95 % CI 1·4, 3·5; P for trend = 0·003). Similarly, they presented a significantly higher risk of developing high blood pressure (adjusted OR 1·6, 95 % CI 1·3, 2·1), central obesity (adjusted OR 2·3, 95 % CI 1·9, 2·7), hypertriacylglycerolaemia (adjusted OR 1·7, 95 % CI 1·1, 2·6) or impaired fasting glucose (adjusted OR 1·6, 95 % CI 1·1, 2·2). In conclusion, an increase in SSB consumption was associated with a higher risk of developing the MetS and other metabolic disorders after 6 years of follow-up in a Mediterranean cohort of university graduates

    Smoking and incidence of glaucoma The SUN Cohort

    Get PDF
    Smoking is a serious global public health concern that has been related to many chronic diseases. However, the effect of smoking on eye disorders has been less studied. The aim of this cohort study was to assess the association between current tobacco smokers and the risk of developing glaucoma and furthermore to evaluate the relationship between passive or former smokers and glaucoma. In this prospective and dynamic cohort, 16,797 participants initially who were found not to have glaucoma were followed up for a median of 8.5 years. Validated data on lifestyle, including tobacco consumption, were assessed at baseline. Information about new diagnosis of glaucoma was collected by follow-up questionnaires every 2 years. The outcome was the incidence of self-reported glaucoma during the follow-up. A subsample was used to validate the glaucoma diagnosis. During the 8.5 years of follow-up, 184 new glaucoma cases were identified. Current smokers had a significantly higher risk of glaucoma compared to participants who had never smoked after controlling for potential confounders (Hazard ratio [HR] 1.88 [95% coefficient interval (CI): 1.26–2.81]; P=0.002). A nonsignificant increased risk was found among former smokers (HR 1.27 [95% CI: 0.88–1.82]; P=0.198). When we assessed the exposure as per the number of cigarette pack-years, a dose–response relationship between pack-years and the risk of glaucoma was found (HR for the 5th quintile versus the 1st quintile: 1.70 [95% IC: 1.10–2.64], P for trend, 0.009). However, no relationship was found between passive smokers and glaucoma. (HR 0.67 [95% CI: 0.37–1.21]; P=0.189). Our results suggest a direct association between current smokers and the incidence of glaucoma. In particular, this association was related to the number of pack-years, which was not found in the case of former smokers nor in the case of passive smokers. Abbreviations: IOP = intraocular pressure, POAG = primary open angle glaucoma, SUN = Seguimiento Universidad de Navarra
    corecore