4,736 research outputs found
Evidence for an endogenous rebound effect impacting long-run car use elasticity to fuel price
This paper presents a structural equation model of household fleet fuel efficiency and car use. It allows to weigh the contribution of car equipment changes and car use adjustments to the price elasticity of household demand for fuel. This model is implemented using a panel dataset of 322 households that were present in each annual wave of the French Car Fleet survey from 1999 to 2007. The longitudinal dimension of this dataset enables to assess the short and long-run adjustments at the household level over a period of fuel price increase. The estimated price elasticities of the demand for fuel are fully consistent with the literature: -0.30 in the short run and -0.76 in the long run. Regarding car use elasticities, accounting for an endogenous rebound effect allowed a striking finding: the sensitivity of household car use to fuel price changes is lower on the long run than on the short run. This paper thus not only provides the latest estimations of elasticities for France, in the early 2000's, it also shows that, on the long run, French households have managed to mitigate the impact of increasing fuel prices on their car mobility by using more fuel efficient cars.Elasticity, Fuel Price, Rebound effect, Energy consumption, Energy efficiency, Car use, Household, Panel data
Antenna technology for advanced mobile communication systems
The onboard antenna front end is the key subsystem conditioning configuration and performance of mobile communication satellites. The objectives of this paper are to demonstrate this key role and to review L-band satellite antenna technology for earth coverage and regional applications. Multibeam arrays are first discussed, then unfurlable and inflatable reflector antennas are described. These technologies are now qualified in Europe for future mobile systems, for which the optimum choice of antenna technology has been found to be the key to efficient use of spectrum and power resources
Sequential simulation used as a novel educational tool aimed at healthcare managers: a patient-centred approach
Background:
A new challenge for healthcare managers is to improve the patient experience. Simulation is often used for clinical assessment and rarely for those operating outside of direct clinical care. Sequential simulation (SqS) is a form of simulation that re-creates care pathways, widening its potential use.
Local problem Numbers, outcome measures and system profiling are used to inform healthcare decisions. However, none of these captures the personal subtleties of a patient’s experience.
Intervention 56 students attended a teaching module using SqS and facilitated workshops as part of their induction week on an MSc International Health Management course. The workshop was voluntary and was offered as an opportunity for the students to gain an insight into the UK health system through the medium of simulation.
Methods:
An evaluation survey incorporating quantitative and qualitative student feedback was conducted. Descriptive statistics were generated from the quantitative data, and thematic analysis was undertaken for the qualitative data.
Results:
There was strong agreement for the acceptability of the workshop approach in relation to the aims and objectives. Likert scale (1–-5) mean total=4.49. Participants responded enthusiastically (revealed through the qualitative data) with ideas related to perspectives sharing, understanding healthcare management and processes and the consideration of feasibility and practicalities. They also suggested other applications that SqS could be used for.
Conclusion:
The SqS approach has demonstrated that simulation has a wider potential than for clinical assessment alone. Further studies are required to determine its potential uses and affordances beyond its current format
Bird flu, avian influenza : the H5N1 virus, poultry, other animals, and people here and elsewhere, from Asia to Africa
Illustré d'une trentaine de photographies originales issues des missions de terrain des vétérinaires et ornithologues du Cirad dans les pays du Sud, le livret fait le point sur ce fléau qui a d'abord frappé les pays du Sud-Est asiatique depuis 1997, avant de gagner l'Europe puis l'Afrique au début 2006. La version anglaise apporte plusieurs éléments nouveaux. L'Inra s'ajoute aux neuf institutions partenaires de l'édition française. Les recherches, conduites dans ce domaine par l'institut, sont mentionnées en page 41 du livret. On trouve également, en page 42, le bilan des opérations de surveillance menées au cours de l'année 2006 dans diverses zones d'implantation des oiseaux sauvages. En pages 33 et 34, les cartes des pays touchés par le virus H5N1 ont été actualisées. Il en est de même concernant la rubrique " Pour en savoir beaucoup plus ", fournissant, en fin de livret, de nouvelles sources d'information accessibles sur le web
Seawater Dielectric Measurements at L-Band with Latest Improvements
Recently, the dielectric constant of seawater at L-band was determined by employing a resonant cavity technique. A dielectric model function has been developed based on the measurement data and the model function has been used for retrieving the ocean salinity. The results indicate that additional accuracy is still needed to resolve the bias correlated with sea surface temperature. This paper reports the improvements that have been made recently for the development of a more accurate seawater dielectric model function. The additional measurements for the open ocean will be addressed in the paper
Relations entre qualité du substrat, flux de matières et activités humaines. Connaissance pour la gestion des ressources en eau de la Région Aquitaine
Les résultats de ce travail de recherche, confirment une fois de plus l'absence de déterminisme apparent entre qualité du substrat et occupation des sols. Ils montrent qu'il n'y a pas de variables prépondérantes ou explicatives de facteurs sociaux ou physiques qui soient responsables des variations affectant les milieux étudiés. Cependant, les analyses régressives des rapports entre homme et milieu montrent les liens étroits entre habitat et types de sol. L'action humaine a des effets sur la couverture végétale, sur les sols et sur l'hydraulique qui avec le climat et la topographie constituent les principaux facteurs d'érosion
Non-targeted Stressful Effects in Normal Human Fibroblast Cultures Exposed to Low Fluences of High Charge, High-Energy (HZE) Particles: Kinetics of Biologic Responses and Significance of Secondary Radiations.
International audienceThe induction of nontargeted stressful effects in cell populations exposed to low fluences of high-charge (Z) and high-energy (E) particles is relevant to estimates of the health risks of space radiation. We investigated the up-regulation of stress markers in confluent normal human fibroblast cultures exposed to 1,000 MeV/u iron ions [linear energy transfer (LET) ∼151 keV/μm] or 600 MeV/u silicon ions (LET ∼50 keV/μm) at mean absorbed doses as low as 0.2 cGy, wherein 1-3% of the cells were targeted through the nucleus by a primary particle. Within 24 h postirradiation, significant increases in the levels of phospho-TP53 (serine 15), p21(Waf1) (CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation were detected, which suggested participation in the stress response of cells not targeted by primary particles. This was supported by in situ studies that indicated greater increases in 53BP1 foci formation, a marker of DNA damage. than expected from the number of primary particle traversals. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure of the cell cultures to 0.2 cGy of 3.7 MeV α particles (LET ∼109 keV/μm) that targets ∼1.6% of nuclei, but not after 0.2 cGy from 290 MeV/u carbon ions (LET ∼13 keV/μm) by which, on average, ∼13% of the nuclei were hit, which highlights the importance of radiation quality in the induced effect. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cell cultures exposed to HZE particles comprise <1% of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10-20 μm. Thus, the latter are unlikely to significantly contribute to stressful effects in cells not targeted by primary HZE particles
Inverse Problems in a Bayesian Setting
In a Bayesian setting, inverse problems and uncertainty quantification (UQ)
--- the propagation of uncertainty through a computational (forward) model ---
are strongly connected. In the form of conditional expectation the Bayesian
update becomes computationally attractive. We give a detailed account of this
approach via conditional approximation, various approximations, and the
construction of filters. Together with a functional or spectral approach for
the forward UQ there is no need for time-consuming and slowly convergent Monte
Carlo sampling. The developed sampling-free non-linear Bayesian update in form
of a filter is derived from the variational problem associated with conditional
expectation. This formulation in general calls for further discretisation to
make the computation possible, and we choose a polynomial approximation. After
giving details on the actual computation in the framework of functional or
spectral approximations, we demonstrate the workings of the algorithm on a
number of examples of increasing complexity. At last, we compare the linear and
nonlinear Bayesian update in form of a filter on some examples.Comment: arXiv admin note: substantial text overlap with arXiv:1312.504
Genome-wide diversity and gene expression profiling of Babesia microti isolates identify polymorphic genes that mediate host-pathogen interactions
Babesia microti, a tick-transmitted, intraerythrocytic protozoan parasite circulating mainly among small mammals, is the primary cause of human babesiosis. While most cases are transmitted by Ixodes ticks, the disease may also be transmitted through blood transfusion and perinatally. A comprehensive analysis of genome composition, genetic diversity, and gene expression profiling of seven B. microti isolates revealed that genetic variation in isolates from the Northeast United States is almost exclusively associated with genes encoding the surface proteome and secretome of the parasite. Furthermore, we found that polymorphism is restricted to a small number of genes, which are highly expressed during infection. In order to identify pathogen-encoded factors involved in host-parasite interactions, we screened a proteome array comprised of 174 B. microti proteins, including several predicted members of the parasite secretome. Using this immuno-proteomic approach we identified several novel antigens that trigger strong host immune responses during the onset of infection. The genomic and immunological data presented herein provide the first insights into the determinants of B. microti interaction with its mammalian hosts and their relevance for understanding the selective pressures acting on parasite evolution
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