166 research outputs found

    Variability of the air temperature and its comparison with MODIS Land Surface Temperature in the Hurd Peninsula of the Livingston Island, Antarctica, between 2000 and 2016

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    Ponencia presentada en: XVIII Congreso de la Asociación Española de Teledetección celebrado en Valladolid del 24 al 27 septiembre 2019.[ES]En los ambientes polares, tan vulnerables al cambio climático, el estudio de la temperatura es imprescindible. Por ello, y en el marco del proyecto PERMASNOW, en este trabajo hemos estudiado en detalle la variación de la temperatura del aire (Ta) en la península Hurd de la isla Livingston (Antártida) y hemos tratado de estimarla a partir de los datos de temperatura de la superficie terrestre (LST, por sus siglas en inglés) del sensor MODIS entre los años 2000 y 2016. Utilizamos datos de Ta media diaria obtenidos en seis puntos, tres estaciones meteorológicas de AEMET y tres estaciones del proyecto PERMASNOW: Juan Carlos I (JCI), Glaciar Johnson (GJ), Glaciar Hurd (GH), Incinerador (INC), Reina Sofía (RS) y Collado Ramos (CR), respectivamente. Los datos MODIS LST son los diurnos y nocturnos de los satélites Terra y Aqua. La tendencia en Ta se ha analizado mediante la regresión localmente ponderada (LOESS, por sus siglas en inglés) y la relación Ta -LST con regresiones lineales múltiples. Concluimos que Ta en el área de estudio varía: se observa en la estación JCI, más cercana a la costa, una tendencia al enfriamiento con valores entre –2,3 y –3,0°C década–1. En cambio, las estaciones más alejadas de la costa y de mayor altitud muestran una tendencia al calentamiento (entre +0,2 y +0,8°C década-1). Los mejores modelos de estimación de Ta a partir de LST y variables temporales se obtienen con los datos diurnos de Terra (R2 = 0,5-0,7; RSE = 2°C), exceptuando GJ, donde la variable LST no es significativa. Con la validación cruzada (CV) se aprecian también, excepto en GJ, mejores resultados con los datos diurnos de Terra (R2 CV = 0,5-0,6; RMSECV = 2,5-2,6°C). Finalmente, concluimos que los datos MODIS LST son útiles para estimar tendencias de Ta a largo plazo en el área de estudio.[EN]In polar zones, where satellite data are very useful due to the limited in situ data, it is therefore essential to study the air temperature behaviour. In the framework of the PERMASNOW project we estimated the air temperature (Ta) in the Hurd Peninsula of Livingston Island (Antarctica) from the land surface temperature (LST) data of the MODIS between 2000 and 2016. We worked with Ta data obtained at six stations (3 AEMET meteorological stations and 3 PERMASNOW project stations: Juan Carlos I (JCI), Johnson Glacier (JG), Hurd Glacier (HG), Incinerator (INC), Reina Sofia (RS) and Collado Ramos (CR), respectively. In addition, we analyzed daytime and nighttime LST data from the Terra and Aqua satellites. Locally weighted regression (LOESS) and multiple linear regressions were used for statistical analysis. We conclude that the Ta in the study area varies: a cooling trend with values between –2.3 and –3.0°C decade-1 is observed in JCI, which is closer to the coast. On the other hand, the stations farther from the coast and at higher altitudes show a warming trend (between +0.2 and +0.8°C decade-1). The best Ta models are obtained with Terra daytime data (R2 = 0.5-0.7 and RSE = 2°C), except JG, where the LST variable is not significant. With cross validation (CV), better results are also seen, except in JG, with the daytime Terra data (R2 CV = 0.5-0.6, RMSECV = 2.5-2.6°C). In summary, MODIS LST data are useful for estimating long-term Ta trends in the study area.Esta investigación fue posible gracias a la financiación de la Agencia Estatal de Investigación a través del proyecto PERMASNOW [CTM2014-52021-R], la ayuda de la Universidad de Oviedo al Grupo de Investigación RSApps en 2018 [PAPI-18-GR-2016-0005] y las ayudas obtenidas por A.C.-P. (“Severo Ochoa” del Gobierno del Principado de Asturias [BP17-151] y “Ayuda Predoctoral” de la Universidad de Oviedo)

    Dietary glycemic index and glycemic load are positively associated with risk of developing metabolic syndrome in middle-aged and elderly adults

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    © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society. Objectives To evaluate how glycemic index (GI) and glycemic load (GL) are associated with the metabolic syndrome (MetS) and its features in middle-aged and elderly adults at high cardiovascular risk. Design Prospective, longitudinal, population-based cohort. Setting PREvenciõn con DIeta MEDiterránea study. Participants Men and women (N = 6,606) divided into three age groups (<65, 65-74, ≥75). Measurements Energy and nutrient intake was evaluated using a validated 137-item food frequency questionnaire. MetS and its features were defined in accordance with the criteria of the American Heart Association and National Heart, Lung, and Blood Institute. Results A positive association was observed between GI and MetS prevalence in the youngest and middle age groups for participants without diabetes mellitus, but no relationship was found for those with diabetes mellitus. During the median follow-up of 4.8 years, higher GI and GL were related to greater risk of MetS in the middle age group, independent of the presence of diabetes mellitus. Changes in dietary GI were associated with risk of developing the high fasting glucose component of the MetS in the oldest age category, and changes in dietary GL were associated with risk of developing abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, and high blood pressure in the youngest age category. Conclusion Dietary GI and GL have a potential role in the development of MetS and associated clinical features, with particular age-dependent considerations.Funded by: Centro Nacional de Investigaciones Cardiovasculares. Grant Number: 06/2007; Instituto de Salud Carlos III; Fondo de Investigación Sanitaria PI. Grant Number: 07/0473; Ministerio de Ciencia e Innovación. Grant Numbers: AGL-2009–13906-C02, AGL2010–22319-C03; Ministerio de Sanidad-Plan Nacional de Drogas. Grant Number: 2010/087; Fondo de Investigaciones Sanitarias. Grant Number: PI1002658 Fundación Mapfre 2010 Government of the Basque Country. Grant Number: IT386–10 University of the Basque Country. Grant Number: UFI 11/32 Catalan government Miguel Servet. Grant Number: 06/00100Peer Reviewe

    Olive oil intake and risk of cardiovascular disease and mortality in the PREDIMED Study

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    It is unknown whether individuals at high cardiovascular risk sustain a benefit in cardiovascular disease from increased olive oil consumption. The aim was to assess the association between total olive oil intake, its varieties (extra virgin and common olive oil) and the risk of cardiovascular disease and mortality in a Mediterranean population at high cardiovascular risk. Methods: We included 7,216 men and women at high cardiovascular risk, aged 55 to 80 years, from the PREvencion con DIeta MEDiterranea (PREDIMED) study, a multicenter, randomized, controlled, clinical trial. Participants were randomized to one of three interventions: Mediterranean Diets supplemented with nuts or extra-virgin olive oil, or a control low-fat diet. The present analysis was conducted as an observational prospective cohort study. The median follow-up was 4.8 years. Cardiovascular disease (stroke, myocardial infarction and cardiovascular death) and mortality were ascertained by medical records and National Death Index. Olive oil consumption was evaluated with validated food frequency questionnaires. Multivariate Cox proportional hazards and generalized estimating equations were used to assess the association between baseline and yearly repeated measurements of olive oil intake, cardiovascular disease and mortality. Results: During follow-up, 277 cardiovascular events and 323 deaths occurred. Participants in the highest energy-adjusted tertile of baseline total olive oil and extra-virgin olive oil consumption had 35% (HR: 0.65; 95% CI: 0.47 to 0.89) and 39% (HR: 0.61; 95% CI: 0.44 to 0.85) cardiovascular disease risk reduction, respectively, compared to the reference. Higher baseline total olive oil consumption was associated with 48% (HR: 0.52; 95% CI: 0.29 to 0.93) reduced risk of cardiovascular mortality. For each 10 g/d increase in extra-virgin olive oil consumption, cardiovascular disease and mortality risk decreased by 10% and 7%, respectively. No significant associations were found for cancer and all-cause mortality. The associations between cardiovascular events and extra virgin olive oil intake were significant in the Mediterranean diet intervention groups and not in the control group. Conclusions: Olive oil consumption, specifically the extra-virgin variety, is associated with reduced risks of cardiovascular disease and mortality in individuals at high cardiovascular risk

    Empirically-derived food patterns and the risk of total mortality and cardiovascular events in the PREDIMED study

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    BACKGROUND & AIMS: There is little evidence on post hoc-derived dietary patterns (DP) and all-cause mortality in Southern-European populations. Furthermore, the potential effect modification of a DP by a nutritional intervention has not been sufficiently assessed. We assessed the association between a posteriori defined baseline major DP and total mortality or cardiovascular events within each of the three arms of a large primary prevention trial (PREDIMED) where participants were randomized to two active interventions with Mediterranean-type diets or to a control group (allocated to a low-fat diet). DESIGN: We followed-up 7216 participants for a median of 4.3 years. A validated 137-item food-frequency questionnaire was administered. Baseline DP were ascertained through factor analysis based on 34 predefined groups. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) for cardiovascular disease (CVD) or mortality across quartiles of DP within each of the three arms of the trial. RESULTS: We identified two major baseline DP: the first DP was rich in red and processed meats, alcohol, refined grains and whole dairy products and was labeled Western dietary pattern (WDP). The second DP corresponded to a 'Mediterranean-type' dietary pattern (MDP). During follow-up, 328 participants died. After controlling for potential confounders, higher baseline adherence to the MDP was associated with lower risk of CVD (adjusted HR for fourth vs. first quartile: 0.52; 95% CI (Confidence Interval): 0.36, 0.74; p-trend <0.001) and all-cause mortality (adjusted HR: 0.53; 95% CI: 0.38, 0.75; p-trend <0.001), regardless of the allocated arm of the trial. An increasing mortality rate was found across increasing quartiles of the WDP in the control group (allocated to a low-fat diet), though the linear trend was not statistically significant (p = 0.098). CONCLUSIONS: Higher adherence to an empirically-derived MDP at baseline was associated with a reduced risk of CVD and mortality in the PREDIMED trial regardless of the allocated arm. The WDP was not associated with higher risk of mortality or cardiovascular events

    Pemetrexed disodium in recurrent locally advanced or metastatic squamous cell carcinoma of the head and neck

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    This phase II study determined response rate of patients with locally advanced or metastatic head and neck cancer treated with pemetrexed disodium, a new multitargeted antifolate that inhibits thymidylate synthase, dihydrofolate reductase and glycinamide ribonucleotide formyl transferase. 35 patients with local or metastatic relapse of squamous cell carcinoma of the head and neck (31 male, 4 female; median age 53 years) were treated with pemetrexed 500 mg m2 administered as a 10-minute infusion on day 1 of a 21-day cycle. Patients received 1 to 8 cycles of therapy. 9 patients (26.5%) had an objective response, with a median response duration of 5.6 months (range 2.9–20 months). 15 (44.1%) had stable disease, and 8 (23.5%) had progressive disease. 2 patients were not assessable for response. Median overall survival was 6.4 months (range 0.7–28.1 months; 95% CI: 3.9–7.7 months). 24 patients (68.6%) experienced grade 3/4 neutropenia, with febrile neutropenia in 4 (11.4%). Grade 3/4 anaemia and thrombocytopenia occurred in 11 (34.3%) and 6 (17.1%) patients, respectively. The most frequent non-haematological toxicity was grade 3/4 mucositis (17.1%; 6 patients). In conclusion, pemetrexed is active in squamous cell carcinoma of the head and neck. Although substantial haematological toxicities were experienced by patients, subsequent studies have shown that these toxicities can be proactively managed by folic acid and vitamin B12 supplementation. © 2001 Cancer Research Campaign http://www.bjcancer.co

    An X-ray Baldwin effect for the narrow Fe K-alpha lines observed in Active Galactic Nuclei

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    The majority of Active Galactic Nuclei (AGN) observed by XMM-Newton reveal narrow Fe K-alpha lines at ~ 6.4 keV, due to emission from cold (neutral) material. There is an X-ray Baldwin effect in Type I AGN, in that the equivalent width of the line decreases with increasing luminosity, with weighted linear regression giving EW ~ L^{-0.17+/-0.08} (Spearman Rank probability of > 99.9%). With current instrumental capabilities it is not possible to determine the precise origin for the narrow line, with both the Broad Line Region and putative molecular torus being possibilities. A possible explanation for the X-ray Baldwin effect is a decrease in covering factor of the material forming the fluorescence line.Comment: 8 pages, 6 figures, accepted by MNRA

    A phase II study of docetaxel in patients with metastatic squamous cell carcinoma of the head and neck

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    This study was designed to evaluate the activity, safety and tolerance of docetaxel (D) in a selected population with metastatic squamous cell carcinoma of the head and neck (SCCHN). Twenty-four patients with no prior palliative therapy were enrolled and received D 100 mg m−2 by 1 h of infusion, every 3 weeks. All but two patients had been evaluated for efficacy on lung metastatic sites. No prophylactic administration of anti-emetics or growth factors was given. A pharmacokinetic study was performed in 22 patients. Twenty-one patients were assessable for response and 24 for toxicity. One hundred and four cycles were administered with a median of 4.5 (range 1–9) per patient. The median cumulative dose was 449 mg m−2. Partial responses were achieved in five patients with a median duration of 18.7 weeks (range 13.1–50.3). The overall response rate was 20.8% with a median duration of 11.0 weeks (range 2.4–52.6). The most frequent side-effect was neutropenia (79.2% grade IV) but with a short duration (median 4 days) and no febrile neutropenia. The incidence of moderate/severe fluid retention was 29.2% with one treatment discontinuation. Other toxicities (all grades) were common (skin 75%, asthenia 50%, infection 29.2%, nausea 16.7%, diarrhoea 12.5%, stomatitis 16.7%, vomiting 8.3% and HSR 8.3%). A mean clearance of 19.6 l h−1 m−2 and an area under the curve of 6.00 μg ml−1 h−1 was found in the pharmacokinetic analysis. Docetaxel is active in this selected population with metastatic SCCHN, with a good tolerance. © 1999 Cancer Research Campaig

    Multiwavelength observations of short time-scale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability

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    This paper combines data from the three preceding papers in order to analyze the multi-waveband variability and spectral energy distribution of the Seyfert~1 galaxy NGC~4151 during the December 1993 monitoring campaign. The source, which was near its peak historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in medium energy (\sim1.5~keV) X-rays, with a normalized variability amplitude (NVA) of 24\%. Weaker (NVA = 6\%) variations (uncorrelated with those at lower energies) were seen at soft γ\gamma-ray energies of \sim100~keV. No significant variability was seen in softer (0.1--1~keV) X-ray bands. In the ultraviolet/optical regime, the NVA decreased from 9\% to 1\% as the wavelength increased from 1275~\AA\ to 6900~\AA. These data do not probe extreme ultraviolet (1200~\AA\ to 0.1~keV) or hard X-ray (2--50~keV) variability. The phase differences between variations in different bands were consistent with zero lag, with upper limits of \ls0.15~day between 1275~\AA\ and the other ultraviolet bands, \ls0.3~day between 1275~\AA\ and 1.5~keV, and \ls1~day between 1275~\AA\ and 5125~\AA. These tight limits represent more than an order of magnitude improvement over those determined in previous multi-waveband AGN monitoring campaigns. The ultraviolet fluctuation power spectra showed no evidence for periodicity, but were instead well-fitted with a very steep, red power-law (a=2.5 a = -2.5 ). If photons emitted at a ``primary" waveband are absorbed by nearby material and ``reprocessed" to produce emission at a secondary waveband, causality arguments require that variations in the secondary band follow those in the primary band. The tight interband correlation and limits on the ultraviolet andComment: 35 pages, LaTeX (including aaspp4), including 7 PostScript figures; To appear in the ApJ (October 20, 1996) Vol. 47
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