Road Safety Valuation under a Stated Choice Framework

The value of fatal risk reductions is a vital input for road safety cost-benefit analysis. It has been traditionally estimated by means of contingent valuation in spite of growing criticism surrounding this approach. Furthermore, many believe that risk-money trade-offs are not well understood due to the difficulty in internalizing tiny risks. We have succeeded in applying the Stated Choice (SC) approach to tackle this problem, using as one of the attributes the number of accidents with fatal victims (i.e. a proxy for risk). To assess the robustness of SC, we conducted an external validity test based on results for three different studies. We investigated if preferences were well defined according to economic theory (i.e. as initial risk increases, the marginal willingness-to-pay should be higher). We also addressed the generally ignored issue of whether there should be a unique value of fatal risk reductions. We found that people can internalize risk consistently from an economic viewpoint, and that although each sample yields different values of risk reductions, there was a relationship between the risk level and the value of risk reductions in each context examined; this evidence could be most helpful within the context of developing countries. Finally, we offer an hypothesis to explain the differences between our values with those obtained in industrialised countries, highlighting the importance of doing local studies rather than transferring imported values

Application of X-Ray microanalysis, diffraction and cytochemical techniques in the study of the structure and chemical composition of inclusions in Olea europaea leaves

4 páginas, 11 figuras.-- Trabajo presentado al EMAG-MICRO 89 celebrado en Londres (Inglaterra) en Septiembre de 1989.Two types of inclusions have been found in mesophyll cells oÍ leaves of Olea eurooaea. The first type is located in the vacuole, and the application of X-Ray microanalysis, X-Ray diffraction and cytochemical techniques shown that these inclusions are composed of calcium oxalate. The second type of inclusion is intranuclear and its proteic nature is demonstrated by means of light microscopy stains. These crystal structures are probably well ordered in three dimensions.Peer reviewe

Mechanisms of dexamethasone-mediated chemokine down-regulation in mild and severe acute pancreatitis

AbstractThis study aimed to investigate the role of therapeutic dexamethasone (Dex) treatment on the mechanisms underlying chemokine expression during mild and severe acute pancreatitis (AP) experimentally induced in rats. Regardless of the AP severity, Dex (1 mg/kg), administered 1 h after AP, reduced the acinar cell activation of extracellular signal-regulated kinase (ERK) and c-Jun-NH2-terminal kinase (JNK) but failed to reduce p38-mitogen-activated protein kinase (MAPK) in severe AP. In both AP models, Dex inhibited the activation of nuclear factor-kappaB (NF-κB) and signal transducers and activators of transcription (STAT) factors. All of this resulted in pancreatic down-regulation of the chemokines monocyte chemoattractant protein-1 (MCP-1) and cytokine-induced neutrophil chemoattractant (CINC). Lower plasma chemokine levels as well as decreased amylasemia, hematocrit and plasma interleukin-1β (Il-1β) levels were found either in mild or severe AP treated with Dex. Pancreatic neutrophil infiltration was attenuated by Dex in mild but not in severe AP. In conclusion, by targeting MAPKs, NF-κB and STAT3 pathways, Dex treatment down-regulated the chemokine expression in different cell sources during mild and severe AP, resulting in decreased severity of the disease

Influence of survey engagement and multiple-choice heuristics in the estimation of the value of a statistical life

Estimating the value of non-market goods, such as reductions in mortality risks due to traffic accidents or air pollution, is typically done using stated choice (SC) data. However, issues with potential estimation biases due to the hypothetical nature of SC experiments arise, as protest choices are common and survey engagement is not constant across respondents. Further, if respondents choose to use different choice mechanisms and this is not considered, the results may also be biased. We designed an SC experiment to estimate the willingness to pay (WTP) for mortality risk reductions, that allowed us to simultaneously estimate the WTP to reduce the risk of traffic accident deaths and cardiorespiratory deaths due to air pollution. We formulated and estimated a multiple heuristic latent class model that also considered two latent constructs: Institutional Belief, to consider protest responses, and survey Engagement as a class membership covariate. We found, first, that individuals with lower institutional belief gave a higher probability of choice to the status-quo alternative, shying away from programs involving governmental action. Second, that not identifying respondents who do not appropriately engage in the experiment, biased the WTP estimators. In our case WTP decreased up to 26% when two different choice heuristics were allowed for in the model. © 202

A study of the relationship between parental mediation and adolescents' digital skills, online risks and online opportunities

In recent years, discussions have sparked about the risks and opportunities that digital technologies may have for adolescents. Some researchers argue that the best way to increase online opportunities and avoid online risks is to increase adolescents' digital skills. For this reason, the first goal of this study was to examine how adolescents' digital skills are related to their online opportunities and online risks behaviours. A second goal was to examine the influence of two ways of parental mediation (active and restrictive) on the level of teenagers’ digital skills, and subsequently their online opportunities and online risks. Finally, we intended to establish the validity and the structure of the Digital Literacy Scale. Using data from a cross-sectional survey of 1.446 Spanish secondary school pupils, we found that more digitally skilled adolescents take more opportunities, and experience more risks. Digital literacy mediates the relationship between restrictive (but not of active) parental mediation and online risks and opportunities. Furthermore, the Digital Literacy Scale was shown to be valid in terms of construct validity. The findings suggest that digital literacy remains essential as it lets teenagers take more opportunities, and that parents should opt for other ways of mediation rather than restrictive mediation

The use of in situ hybridisation and immunocytochemistry to characterise coiled bodies in plant meiocytes

2 páginas, 2 figuras.-- Trabajo presentado a la XI European Conference on Electron Microscopy- EUREM11 celebrada en Dublín (Irlanda) del 26 al 30 de Agosto de 1996.This study was supported by project DGICYT PB92-0079-CO3-O3.Peer reviewe

Preliminary characterization of ssps (Seed Storage Proteins) in Argania spinosa L.

4 páginas, 2 figuras, 1 tabla.-- Comunicación presentada al 3rd International SMBBM Congress, IUBMB Special Meeting & 6th FASBMB Congress, celebrado en Marrakech (Marruecos) del 20 al 24 de Abril de 2009.SSPs (Seed Storage Proteins) of the 11S type have been preliminary characterized in the seeds of the argan tree, an endemic species from Morocco. Protein extracts from mature seeds were prepared by using different solutions in order to assess the solubility of the major protein forms. SSPs of the 11S type were classified as albumins according to the further SDS-PAGE analysis of these extracts. The combination of both reducing- and non-reducing conditions for the SDS-PAGE analysis, together with immunoblot experiments allowed us to determine the presence of three precursor forms of these proteins (pro1, pro2 and pro3), which are composed of six individual peptides (p1 to p6) in different combinations.This work was funded by Spanish BFU2004-00601/BFI and BFU2008-00629 projects. M. Allach thanks the research bursary granted by UNESCO/L´ORÉAL and L´ORÉAL Morocco.Peer reviewe

Sucesión y restauración en ambientes semiáridos

Extensas áreas abandonadas del sureste peninsular están experimentando actualmente procesos de sucesión secundaria sobre los que tenemos un conocimiento muy escaso. La sucesión secundaria en ambientes áridos es muy lenta y su resultado incierto, ya que el establecimiento de determinadas especies y comunidades está muy limitado. Los esfuerzos para restaurar zonas abandonadas deben basarse en un conocimiento sólido de la sucesión, empleando especies viables, propias de etapas intermedias, capaces de impulsar la sucesión vegetal

Estimating the willingness-to-pay and value of risk reduction for car occupants in the road environment

In recent years there has been a re-focus on the valuation of a statistical life (VSL) from the ex post or human capital method to an ex ante willingness to pay approach. This is in part a recognition that we may have been undervaluing the cost of fatalities and injuries to society associated with crashes, but also a strong belief in the need to focus on establishing the amount, ex ante, that individuals are willing to pay to reduce the risk of exposure to circumstances that might lead to death or degree of injury on the road network. This study has developed a framework in which to identify the heterogeneity in willingness to pay (WTP) by individuals who are drivers or passengers in cars to avoid being killed or injured. A stated choice experiment approach is developed. The empirical setting is a choice of route for a particular trip that a sample of individuals periodically undertakes in Australia. The particular trip is described in enough detail to provide the respondent with a familiar market environment, providing all the relevant background information required for making a decision. Mixed logit models are estimated to obtain the marginal (dis)utilities associated with each influence on the choice amongst the attribute packages offered in the stated choice scenarios. These estimates are used to obtain the WTP distributions for fatality and injury avoidance, which are then aggregated to obtain estimates of the value of risk reduction (VRR), often referred to generically as the value of a statistical life