Combining Averting Behavior and Contingent Valuation Data: An Application to Drinking Water Treatment

This paper is an empirical application that combines averting behavior with contingent valuation data. Consistency tests are performed incorporating alternative heteroscedastic structures in the bivariate probit models by taking advantage of the different information content that characterizes each data source. We look at three covariates not yet examined in the literature when combining stated and revealed preferred data to explain the variance in the models: income, the bid in the contingent valuation questionnaire, and the distance between the bid and the averting expenditures with drinking water. The models estimated include between and within data sources heteroscedasticity. The results obtained allow the combination of the two data sources under a common preference structure.averting behavior, combination of data sets, consistency tests, contingent valuation, revealed preferred data

Identifying Nonrational Behavior in Recreation Demand Models

In the context of an estimated RPL (Random Parameters Logit) choice model of recreational demand for the game reserves of the KwaZulu-Natal province in South Africa, a test on the existence of an underlying rational preference structure is presented. The proposed procedure allows to identify nonrational behavior in the sample. Using two different data sets extracted from the original data base, we show that by improving the data, apparent nonrationality can be eliminated and welfare analysis may be safely conducted.N/

Combining Averting Behavior and Contingent Valuation Data: an Application to Drinking Water Treatment

This paper is an empirical application that combines averting behavior with contingent valuation data. Consistency tests are performed incorporating alternative heteroscedastic structures in the bivariate probit models by taking advantage of the different information content that characterizes each data source. We look at three covariates not yet examined in the literature when combining stated and revealed preferred data to explain the variance in the models: income, the bid in the contingent valuation questionnaire, and the distance between the bid and the averting expenditures with drinking water. The models estimated include between and within data sources heteroscedasticity. The results obtained allow the combination of the two data sources under a common preference structure.N/

Lower Extremity Motor Impairments in Ambulatory Chronic Hemiparetic Stroke: Evidence for Lower Extremity Weakness and Abnormal Muscle and Joint Torque Coupling Patterns

Although global movement abnormalities in the lower extremity poststroke have been studied, the expression of specific motor impairments such as weakness and abnormal muscle and joint torque coupling patterns have received less attention. We characterized changes in strength, muscle coactivation and associated joint torque couples in the paretic and nonparetic extremity of 15 participants with chronic poststroke hemiparesis (age 59.6 ± 15.2 years) compared with 8 age-matched controls. Participants performed isometric maximum torques in hip abduction, adduction, flexion and extension, knee flexion and extension, ankle dorsi- and plantarflexion and submaximal torques in hip extension and ankle plantarflexion. Surface electromyograms (EMGs) of 10 lower extremity muscles were measured. Relative weakness (paretic extremity compared with the nonparetic extremity) was measured in poststroke participants. Differences in EMGs and joint torques associated with maximum voluntary torques were tested using linear mixed effects models. Results indicate significant poststroke torque weakness in all degrees of freedom except hip extension and adduction, adductor coactivation during extensor tasks, in addition to synergistic muscle coactivation patterns. This was more pronounced in the paretic extremity compared with the nonparetic extremity and with controls. Results also indicated significant interjoint torque couples during maximum and submaximal hip extension in both extremities of poststroke participants and in controls only during maximal hip extension. Additionally, significant interjoint torque couples were identified only in the paretic extremity during ankle plantarflexion. A better understanding of these motor impairments is expected to lead to more effective interventions for poststroke gait and posture

Positive Selection of B Cells Expressing Low Densities of Self-reactive BCRs

B cell tolerance or autoimmunity is determined by selective events. Negative selection of self-reactive B cells is well documented and proven. In contrast, positive selection of conventional B cells is yet to be firmly established. Here, we demonstrate that developing self-reactive B cells are not always highly sensitive to the deletion mechanisms imposed by membrane-bound self-antigens. At low amounts, membrane-bound antigens allow survival of B cells bearing a single high affinity self-reactive B cell receptor (BCR). More importantly, we show that forced allelic inclusion modifies B cell fate; low quantities of self-antigen induce the selection and accumulation of increased numbers of self-reactive B cells with decreased expression of antigen-specific BCRs. By directly measuring antigen binding by intact B cells, we show that the low amounts of self-antigen select self-reactive B cells with a lower association constant. A fraction of these B cells is activated and secretes autoantibodies that form circulating immune complexes with self-antigen. These findings demonstrate that conventional B cells can undergo positive selection and that the fate of a self-reactive B cell depends on the quantity of self-antigen, the number of BCRs engaged, and on its overall antigen-binding avidity, rather than on the affinity of individual BCRs

Grandfather international : a cross-country comparison of an older people integrated assessment Portugal and Italy

Scientists theorize that aging likely results from a combination of many factors. Genes, lifestyle and disease can all affect the rate of ageing. Studies have indicated that people age at different rates and in different ways. Frailty is a state of increased vulnerability with multisystem loss of physiologic reserves and decreased response to stressors, predicting adverse health outcomes. The phenotype of frailty is characterized by: unintentional weight loss, self-reported exhaustion, weakness (low grip strength), slow walking speed and low physical activity. From our knowledge no studies were found that relate the frailty, hearing, the executive functions of language, speech rate and also the swallowing process. The research question is as follows: Is there any relation between frailty speech, language, hearing and swallow? This study is part of a project between Italy and Portugal involving professionals from various fields.N/

Molecular structure and polymorphism of a cyclohexanediol: trans-1,4-cyclohexanedimethanol

This study aims to investigate the molecular structure and polymorphism of trans-1,4-cyclohexanedimethanol, including the bi-axial/bi-equatorial equilibrium and the nature of the intermolecular H-bond networks in condensed phases created by the hydroxyl group torsions. The full conformational space of the single molecule was explored by MP2 calculations, showing that the optimized bi-equatorial conformers have similar stability and the bi-axial ones have much higher energies. The hydroxymethyl substituents have preference for gauche/anti or gauche+/gauche− conformations. Polymorphic forms were generated by crystallization from solutions and by cooling the melt, which were characterized by a combination of techniques: DSC, PLTM and XRD. Two polymorphs were isolated and their crystal structures were solved by direct methods based on single-crystal X-ray analysis. Both were found to contain two of the most stable conformers found in the computational calculations. The influence of H-bonding in the polymorphic structures was verified by analysis of the structural differences between the geometries present in the polymorphs determined by XRD and their single molecule counterparts resulting from the theoretical calculations. The bi-axial conformations are destabilized over the bi-equatorial ones in isolated and crystalline forms of trans-1,4-cyclohexanedimethanol

Water-sediment physicochemical dynamics in a large reservoir in the Mediterranean region under multiple stressors

Nowadays, the Mediterranean freshwater systems face the threat of water scarcity, along with multiple other stressors (e.g., organic and inorganic contamination, geomorphological alterations, invasive species), leading to the impairment of their ecosystem services. All these stressors have been speeding up, due to climate variability and land cover/land use changes, turning them into a big challenge for the water management plans. The present study analyses the physicochemical and phytoplankton biomass (chlorophyll-a) dynamics of a large reservoir, in the Mediterranean region (Alqueva reservoir, Southern Portugal), under diverse meteorological conditions and land cover/land use real scenarios (2017 and 2018). The most important stressors were identified and the necessary tools and information for a more effective management plan were provided. Changes in these parameters were further related to the observed variations in the meteorological conditions and in the land cover/land use. The increase in nutrients and ions in the water column, and of potentially toxic metals in the sediment, were more obvious in periods of severe drought. Further, the enhancement of nutrients concentrations, potentially caused by the intensification of agricultural activities, may indicate an increased risk of water eutrophication. The results highlight that a holistic approach is essential for a better water resources management strategy