Improving scope sensitivity in contingent valuation: joint and separate evaluation of health states

We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called “evaluability,” does not apply here. The paper presents new explanations based on the role of preference imprecision

On the Sigma-invariants of even Artin groups of FC-type

In this paper we study Sigma-invariants of even Artin groups of FC-type, extending some known results for right-angled Artin groups. In particular, we define a condition that we call the strong n-link condition for a graph Gamma and prove that it gives a sufficient condition for a character chi : A(Gamma) -> Z to satisfy chi] is an element of Sigma(n)(A(Gamma), Z). This implies that the kernel A(Gamma)(chi) = ker chi is of type FPn. We prove the homotopical version of this result as well and discuss partial results on the converse. We also provide a general formula for the free part of H-n(A(Gamma)(chi); F) as an Ft(+/- 1)]-module with the natural action induced by chi. This gives a characterization of when H-n(A(Gamma)(chi); F) is a finite dimensional vector space over F

Even Artin Groups

Right-angled Artin groups form an interesting family of groups both from analgebraic and a topological point of view. There are a lot of well-known propertiesof right-angled Artin groups: for example they are poly-free, locallyindicable, right orderable and residually finite. Besides, also many importantproblems are well understood for these groups such as the word problem, therigidity problem, Serre's question or the K(pi, 1) conjecture.In this thesis, we will study some of these properties for a bigger andinteresting subfamily of Artin groups: even Artin groups. We generalizemany of these properties either for even Artin groups in full genarility or forsome big and interesting subfamilies.In particular, we prove that even Artin groups of FC type and large evenArtin groups are poly-free (which, as we will see, implies that they are alsolocally indicable and right orderable) and that even Artin groups of FC typeand general Artin groups based on trees are residually finite. Finally, weanswer Serre's question for the whole family of even Artin groups.<br /

La valoración monetaria de los costes humanos de la siniestralidad vial en España

ResumenLos análisis coste-beneficio en el ámbito de la seguridad vial han de computar la totalidad de los costes, y dentro de ellos ocupan un lugar clave los costes humanos. En esta nota se da cuenta de dos estudios promovidos por la Dirección General de Tráfico orientados a la obtención de valores oficiales para España de los costes asociados a las víctimas mortales y no mortales de los accidentes de tráfico. Mediante la combinación del enfoque de la valoración contingente con la técnica de la lotería estándar (modificada), y con muestras amplias (n1=2020, n2=2000) representativas de la población española, se estimó en 1,4 millones de euros el valor monetario de prevenir un fallecido por accidente de tráfico. Para las lesiones graves y leves, los valores estimados fueron de 219.000 y 6100 euros, respectivamente. Las cifras obtenidas tienen un orden de magnitud similar al de los países de nuestro entorno.AbstractCost-benefit analyses in the field of road safety compute human costs as a key component of total costs. The present article presents two studies promoted by the Directorate-General for Traffic aimed at obtaining official values for the costs associated with fatal and non-fatal traffic injuries in Spain. We combined the contingent valuation approach and the (modified) standard gamble technique in two surveys administered to large representative samples (n1=2,020, n2=2,000) of the Spanish population. The monetary value of preventing a fatality was estimated to be 1.4 million euros. Values of 219,000 and 6,100 euros were obtained for minor and severe non-fatal injuries, respectively. These figures are comparable to those observed in neighboring countries

Grafted Sepiolites for the Removal of Pharmaceuticals in Water Treatment

The increased detection of pharmaceuticals in finished drinking water has become a growing cause of concern in recent years. The removal of atenolol, ranitidine, and carbamazepine by sepiolite, following functionalization of its surface by organosilane grafting, constituted the subject of this investigation. Silylated surfaces include octyl, γ-aminopropyl, 3-chloropropyl, and triphenyl moieties. The sorption of atenolol and ranitidine was higher on sepiolite functionalized with 3-chloropropyl, while carbamazepine showed a higher sorption on sepiolite with triphenyl groups. Filtration experiments of both ranitidine and carbamazepine on octyl- and triphenyl-sepiolite, respectively, showed a higher retention of ranitidine in comparison to carbamazepine, in spite of the fact that the number of sorption sites was lower due to its higher binding rate.Ministerio de Educación y Cultura CTM2013-42306-R, CTM2016-77168-

Baixos níveis de chumbo no sangue e sucesso escolar nas crianças entre os 7-8 anos na Comunidade de Madrid (Espanha)

Background: Lead affects the behavioral and cognitive functions of children. The current lead safety level for avoiding these adverse effects is still controversial.Methods of study: A cross-sectional study included 511 children from 23 primary schools within the Comunidad de Madrid (the Madrid Region –including the city of Madrid and the large urban-industrial conurbation of satellite towns surrounding it), Spain. The children’s blood lead levels were determined by atomic absorption spectrophotometry. In addition, the teachers completed an eight-item questionnaire about the children’s behavior and academic achievement. Parents filled in a self-completion survey about the sociodemographic variables of the children and the family.Results: The mean Blood Lead Level (BLL) of the children was 4.1 μg/dL SD 1.6 μg/dL (log transformed 3.8 μg/dL SD 0.2 μg/dL). Multivariate analysis controlling for relevant sociodemographic cofactors (among others, sex, age and educational level of the parents) showed a negative association, but this was not statistically significant.Conclusions: Despite the low blood lead levels found in the children of the Comunidad de Madrid (Spain) and the design limitations of the study, the results obtained suggest the existence of a harmful, but not statistically significant, effect of blood lead on the behavior and academic achievement of children.Objetivos: El plomo en sangre provoca en los niños efectos sobre las funciones cognitivas y sobre el comportamiento. No existe acuerdo sobre los niveles en sangre que evitarían esos efectos.Métodos: Estudio transversal en el que participaron 511 niños pertenecientes a 23 colegios de la Comunidad de Madrid (la ciudad de Madrid y su Corona Metropolitana), España, a los que se les determinaron los niveles de plomo en sangre por espectrofotometría de absorción atómica. Además, los profesores cumplimentaron un cuestionario de ocho preguntas sobre aspectos conductuales y de rendimiento académico de los niños. Los padres rellenaron a su vez una encuesta relativa a las variables sociodemográficas de los niños y su familia.Resultados: El nivel medio de plomo en sangre fue de 4,1 μg/dL DE 1,6 μg/dL (log transformado 3,8 μg/dL, DE 0,2 μg/dL). El análisis multivariado controlando por cofactores sociodemográficos relevantes (entre otros, sexo, edad y nivel de educación de los padres) mostró una asociación negativa, pero sin significación estadística.Conclusiones: A pesar de las bajas concentraciones de plomo encontradas en la sangre de los niños de la Comunidad de Madrid y de las limitaciones del diseño, los resultados obtenidos sugieren la existencia de un efecto nocivo del plomo en sangre sobre la conducta y el rendimiento académico de los niños, no significativo.Enquadramento: O chumbo afeta as funções comportamentais e cognitivas das crianças. Não há consenso acerca do atual nível de segurança do chumbo que visa evitar estes efeitos adversos.Métodos: Estudo transversal com 511 crianças de 23 escolas primárias da Comunidade de Madrid, Espanha (Região de Madrid -incluindo a cidade de Madrid e a aglomeração urbano-industrial das cidades satélites que a rodeiam). O nível de chumbo no sangue das crianças foi determinado por espectrofotometria de absorção atómica. Além disso, os professores responderam a um questionário de oito itens sobre o comportamento das crianças e desempenho escolar. Os pais preencheram um questionário sobre as variáveis sociodemográficas das crianças e da família.Resultados: O nível médio de chumbo no sangue das crianças foi de 4,1 μg/dL SD 1,6 μg/dL (log transformado 3,8 μg/dL SD 0,2 μg/ dL). A análise multivariada controlada pelas variáveis sociodemográficas (idade, sexo e nível de escolaridade dos pais, entre outros) mostrou uma associação negativa, mas esta não foi estatisticamente significativa.Conclusões: Apesar dos baixos níveis de chumbo encontrados no sangue das crianças da Comunidade de Madrid (Espanha) e das limitações do desenho do estudo os resultados obtidos, embora não estatisticamente significativos, sugerem a existência de efeitos nocivos do chumbo no sangue das crianças sobre o seu comportamento e desempenho escolar

Abacavir/Lamivudine Versus Tenofovir/Emtricitabine in Virologically Suppressed Patients Switching from Ritonavir-Boosted Protease Inhibitors to Raltegravir

There are few clinical data on the combination abacavir/lamivudine plus raltegravir. We compared the outcomes of patients from the SPIRAL trial receiving either abacavir/lamivudine or tenofovir/emtricitabine at baseline who had taken at least one dose of either raltegravir or ritonavir-boosted protease inhibitors. For the purpose of this analysis, treatment failure was defined as virological failure (confirmed HIV-1 RNA ≥50 copies/ml) or discontinuation of abacavir/lamivudine or tenofovir/emtricitabine because of adverse events, consent withdrawal, or lost to follow-up. There were 143 (72.59%) patients with tenofovir/emtricitabine and 54 (27.41%) with abacavir/lamivudine. In the raltegravir group, there were three (11.11%) treatment failures with abacavir/lamivudine and eight (10.96%) with tenofovir/emtricitabine (estimated difference 0.15%; 95% CI -17.90 to 11.6). In the ritonavir-boosted protease inhibitor group, there were four (14.81%) treatment failures with abacavir/lamivudine and 12 (17.14%) with tenofovir/emtricitabine (estimated difference -2.33%; 95% CI -16.10 to 16.70). Triglycerides decreased and HDL cholesterol increased through the study more pronouncedly with abacavir/lamivudine than with tenofovir/emtricitabine and differences in the total-to-HDL cholesterol ratio between both combinations of nucleoside reverse transcriptase inhibitors (NRTIs) tended to be higher in the raltegravir group, although differences at 48 weeks were not significant. While no patient discontinued abacavir/lamivudine due to adverse events, four (2.80%) patients (all in the ritonavir-boosted protease inhibitor group) discontinued tenofovir/emtricitabine because of adverse events (p=0.2744). The results of this analysis do not suggest that outcomes of abacavir/lamivudine are worse than those of tenofovir/emtricitabine when combined with raltegravir in virologically suppressed HIV-infected adults

Stability Analysis of a Run-of-River Diversion Hydropower Plant With Surge Tank And Spillway in the Head Pond

Run-of-river hydropower plants usually lack significant storage capacity; therefore, the more adequate control strategy would consist of keeping a constant water level at the intake pond in order to harness the maximum amount of energy from the river flow or to reduce the surface flooded in the head pond. In this paper, a standard PI control system of a run-of-river diversion hydropower plant with surge tank and a spillway in the head pond that evacuates part of the river flow plant is studied. A stability analysis based on the Routh-Hurwitz criterion is carried out and a practical criterion for tuning the gains of the PI controller is proposed. Conclusions about the head pond and surge tank areas are drawn from the stability analysis. Finally, this criterion is applied to a real hydropower plant in design state; the importance of considering the spillway dimensions and turbine characteristic curves for adequate tuning of the controller gains is highlighte

San Pedro Martir observations of microvariability in obscured quasars

Fast brightness variations are a unique tool to probe the innermost regions of active galactic nuclei (AGN). These variations are called microvariability or intra-night variability, and this phenomenon has been monitored in samples of blazars and unobscured AGNs. Detecting optical microvariations in targets hidden by the obscuring torus is a challenging task because the region responsible for the variations is hidden from our sight. However, there have been reports of fast variations in obscured Seyfert galaxies in X-rays, which rises the question whether microvariations can also be detected in obscured AGNs in the optical regime. Because the expected variations are very small and can easily be lost within the noise, the analysis requires a statistical approach. We report the use of a one-way analysis of variance, ANOVA, with which we searched for microvariability. ANOVA was successfully employed in previous studies of unobscured AGNs. As a result, we found microvariable events during three observing blocks: in two we observed the same object (Mrk 477), and in another, J0759+5050. The results on Mrk 477 confirm previous findings. However, since Mrk 477 is quite a peculiar target with hidden broad-line regions, we cannot rule out the possibility that we have serendipitously chosen a target prone to variations.Comment: Research note, 5 pages, 2 figures, accepted for publication in Astronomy and Astrophysic