984 resultados para super-orbital re-entry
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[cat] Mentre que una creixent literatura que ha examinat la relaci entre la renda i la despesa sanitria suggereix que els serveis sanitaris sn un be de luxe (elasticitat renda superior a la unitat), aquesta conclusi es contnuament debatuda atesa l'heterogenetat dels resultats. Aquest article testa la hiptesis dels serveis sanitaris com bens de luxe fent server anlisi de meta- regressi, particularment analitzant l'existncia de biaixos de selecci de publicaci, precisi aix com biaixos d'agregaci. Els resultats apunten l'existncia d'un biaix de publicaci, robust independentment dels controls analitzats. Els biaixos de precisi i agregaci semblen tenir un paper en la generaci de les estimacions de l'elasticitat renda. Els nostres resultat suggereixen que l'elasticitat renda dels serveis sanitaris un cop corregir pels biaixos esmentat varien entre 0.26 i 0.84, per no podem rebutjar que la elasticitat renda es igual a la unitat en algunes estimacions de l'elasticitat corregides.
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In this review it is presented some aspects of electrothermal atomic absorption spectrometry with tungsten coil (ETAW-AAS) since its beginning until the present days as well as the perspectives for this technique. Some aspects concerning its development and theoretical concepts are discussed. The analytical figures of merit such as limit of detection (LD), characteristic mass (m0), relative standard deviation (RSD), accuracy and precision are evaluated, compared and discussed considering published works. It is also evaluated its advantages, applications, limitations and instrumental development. The use of diode laser as radiation source and its perspectives to ETAW are also discussed.
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Background: Polyphenols may lower the risk of cardiovascular disease (CVD) and other chronic diseases due to their antioxidant and anti-inflammatory properties, as well as their beneficial effects on blood pressure, lipids and insulin resistance. However, no previous epidemiological studies have evaluated the relationship between the intake of total polyphenols intake and polyphenol subclasses with overall mortality. Our aim was to evaluate whether polyphenol intake is associated with all-cause mortality in subjects at high cardiovascular risk. Methods: We used data from the PREDIMED study, a 7,447-participant, parallel-group, randomized, multicenter, controlled five-year feeding trial aimed at assessing the effects of the Mediterranean Diet in primary prevention of cardiovascular disease. Polyphenol intake was calculated by matching food consumption data from repeated food frequency questionnaires (FFQ) with the Phenol-Explorer database on the polyphenol content of each reported food. Hazard ratios (HR) and 95% confidence intervals (CI) between polyphenol intake and mortality were estimated using time-dependent Cox proportional hazard models. Results: Over an average of 4.8 years of follow-up, we observed 327 deaths. After multivariate adjustment, we found a 37% relative reduction in all-cause mortality comparing the highest versus the lowest quintiles of total polyphenol intake (hazard ratio (HR) = 0.63; 95% CI 0.41 to 0.97; P for trend = 0.12). Among the polyphenol subclasses, stilbenes and lignans were significantly associated with reduced all-cause mortality (HR =0.48; 95% CI 0.25 to 0.91; P for trend = 0.04 and HR = 0.60; 95% CI 0.37 to 0.97; P for trend = 0.03, respectively), with no significant associations apparent in the rest (flavonoids or phenolic acids). Conclusions: Among high-risk subjects, those who reported a high polyphenol intake, especially of stilbenes and lignans, showed a reduced risk of overall mortality compared to those with lower intakes. These results may be useful to determine optimal polyphenol intake or specific food sources of polyphenols that may reduce the risk of all-cause mortality.
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The truncated hemoglobin N, HbN, of Mycobacterium tuberculosis is endowed with a potent nitric oxide dioxygenase (NOD) activity that allows it to relieve nitrosative stress and enhance in vivo survival of its host. Despite its small size, the protein matrix of HbN hosts a two-branched tunnel, consisting of orthogonal short and long channels, that connects the heme active site to the protein surface. A novel dual-path mechanism has been suggested to drive migration of O(2) and NO to the distal heme cavity. While oxygen migrates mainly by the short path, a ligand-induced conformational change regulates opening of the long tunnel branch for NO, via a phenylalanine (PheE15) residue that acts as a gate. Site-directed mutagenesis and molecular simulations have been used to examine the gating role played by PheE15 in modulating the NOD function of HbN. Mutants carrying replacement of PheE15 with alanine, isoleucine, tyrosine and tryptophan have similar O(2)/CO association kinetics, but display significant reduction in their NOD function. Molecular simulations substantiated that mutation at the PheE15 gate confers significant changes in the long tunnel, and therefore may affect the migration of ligands. These results support the pivotal role of PheE15 gate in modulating the diffusion of NO via the long tunnel branch in the oxygenated protein, and hence the NOD function of HbN.
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El present estudi t com a finalitat estudiar qu s el reposicionament i quins sn els factors que lenvolten. Pretn establir quines sn les principals causes que condueixen a reposicionar una marca, aix com tamb analitzar si el reposicionament s equivalent que quan va sorgir, o si pel contrari ha evolucionat, i com ho ha fet. Amb aquest estudi intentarem esbrinar com es reposicionen les marques en lactualitat.
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In this paper, we report a preliminary analysis of the impact of Global Navigation Satellite System Reections (GNSS-R) data on ionospheric monitoring over the oceans. The focus will be on a single polar Low Earth Orbiter (LEO) mission exploiting GNSS-R as well as Navigation (GNSS-N) and Occultation (GNSS-O) total electron content (TEC) measurements. In order to assess impact of the data, we have simulated GNSS-R/O/N TEC data as would be measured from the LEO and from International Geodesic Service (IGS) ground stations, with an electron density (ED) eld generated using a climatic ionospheric model. We have also developed a new tomographic approach inspired by the physics of the hydrogen atom and used it to effectively retrieve the ED eld from the simulated TEC data near the orbital plane. The tomographic inversion results demonstrate the signicant impact of GNSS-R: three-dimensional ionospheric ED elds are retrieved over the oceans quite accurately, even as, in the spirit of this initial study, the simulation and inversion approaches avoided intensive computation and sophisticated algorithmic elements (such as spatio-temporal smoothing). We conclude that GNSS-R data over the oceans can contribute signicantly to a Global/GNSS Ionospheric Observation System (GIOS). Index Terms Global Navigation Satellite System (GNSS), Global Navigation Satellite System Reections (GNSS-R), ionosphere, Low Earth Orbiter (LEO), tomography.
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Daphne du Mauriers popular classic Rebecca (1938) was traditionally marketed as a Gothic romance in which two lovers conquered the evil women that separated them. In more recent years, some feminist critics have provided a very different view of the story as a Gothic narrative about the dangers women suffer under patriarchal control. In this thesis, I propose, through a Gothic Studies and a Gender Studies reading, that the victim/abuser statuses in du Mauriers novel cannot be equated to femininity and masculinity, respectively. Instead, I argue that villainy in Rebecca comes from being in a powerful position within patriarchya position that is occupied by both male and female characters
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The present thesis in focused on the minimization of experimental efforts for the prediction of pollutant propagation in rivers by mathematical modelling and knowledge re-use. Mathematical modelling is based on the well known advection-dispersion equation, while the knowledge re-use approach employs the methods of case based reasoning, graphical analysis and text mining. The thesis contribution to the pollutant transport research field consists of: (1) analytical and numerical models for pollutant transport prediction; (2) two novel techniques which enable the use of variable parameters along rivers in analytical models; (3) models for the estimation of pollutant transport characteristic parameters (velocity, dispersion coefficient and nutrient transformation rates) as functions of water flow, channel characteristics and/or seasonality; (4) the graphical analysis method to be used for the identification of pollution sources along rivers; (5) a case based reasoning tool for the identification of crucial information related to the pollutant transport modelling; (6) and the application of a software tool for the reuse of information during pollutants transport modelling research. These support tools are applicable in the water quality research field and in practice as well, as they can be involved in multiple activities. The models are capable of predicting pollutant propagation along rivers in case of both ordinary pollution and accidents. They can also be applied for other similar rivers in modelling of pollutant transport in rivers with low availability of experimental data concerning concentration. This is because models for parameter estimation developed in the present thesis enable the calculation of transport characteristic parameters as functions of river hydraulic parameters and/or seasonality. The similarity between rivers is assessed using case based reasoning tools, and additional necessary information can be identified by using the software for the information reuse. Such systems represent support for users and open up possibilities for new modelling methods, monitoring facilities and for better river water quality management tools. They are useful also for the estimation of environmental impact of possible technological changes and can be applied in the pre-design stage or/and in the practical use of processes as well.
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Invocatio: [hepreaa].
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Invocatio: Q.F.F.Q.S.
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Painovuosi nimekkeest.
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A simple, four-step method for better introducing undergraduate students to the fundamentals of molecular orbital (MO) theory of the polyatomic molecules H2O, NH3, BH3 and SiH4 using group theory is reported. These molecules serve to illustrate the concept of ligand group orbitals (LGOs) and subsequent construction of MO energy diagrams on the basis of molecular symmetry requirements.
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1 kartta : vr. ; 43,8 x 54,8 cm, lehti 46 x 56,7 cm.
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La Carelie, et lIngrie, ou Ingermenland. Par le S:r Sanson geogr ord:re du roy. 1 kartta : vr. ; 46,7 x 55 cm, lehti 48,5 x 59,3 cm.