Measuring and Explaining the Increase of Travel Distance : A Multilevel Analysis Using Repeated Cross Sectional Travel Surveys

We want to shed some light on the development of person mobility by analysing the repeated cross-sectional data of the four National Travel Surveys (NTS) that were conducted in Germany since the mid seventies. The above mentioned driving forces operate on different levels of the system that generates the spatial behaviour we observe: Travel demand is derived from the needs and desires of individuals to participate in spatially separated activities. Individuals organise their lives in an interactive process within the context they live in, using given infrastructure. Essential determinants of their demand are the individual's socio-demographic characteristics, but also the opportunities and constraints defined by the household and the environment are relevant for the behaviour which ultimately can be realised. In order to fully capture the context which determines individual behaviour, the (nested) hierarchy of persons within households within spatial settings has to be considered. The data we will use for our analysis contains information on these three levels. With the analysis of this micro-data we attempt to improve our understanding of the afore subsumed macro developments. In addition we will investigate the prediction power of a few classic sociodemographic variables for the daily travel distance of individuals in the four NTS data sets, with a focus on the evolution of this predictive power. The additional task to correctly measure distances travelled by means of the NTS is threatened by the fact that although these surveys measure the same variables, different sampling designs and data collection procedures were used. So the aim of the analysis is also to detect variables whose control corrects for the known measurement error, as a prerequisite to apply appropriate models in order to better understand the development of individual travel behaviour in a multilevel context. This task is complicated by the fact that variables that inform on survey procedures and outcomes are only provided with the data set for 2002 (see Infas and DIW Berlin, 2003).

A new neuropsychological instrument measuring effects of age and drugs on fitness to drive: development, reliability, and validity of MedDrive

Background: Current guidelines underline the limitations of existing instruments to assess fitness to drive and the poor adaptability of batteries of neuropsychological tests in primary care settings. Aims: To provide a free, reliable, transparent computer based instrument capable of detecting effects of age or drugs on visual processing and cognitive functions. Methods: Relying on systematic reviews of neuropsychological tests and driving performances, we conceived four new computed tasks measuring: visual processing (Task1), movement attention shift (Task2), executive response, alerting and orientation gain (Task3), and spatial memory (Task4). We then planned five studies to test MedDrive's reliability and validity. Study-1 defined instructions and learning functions collecting data from 105 senior drivers attending an automobile club course. Study-2 assessed concurrent validity for detecting minor cognitive impairment (MCI) against useful field of view (UFOV) on 120 new senior drivers. Study-3 collected data from 200 healthy drivers aged 20-90 to model age related normal cognitive decline. Study-4 measured MedDrive's reliability having 21 healthy volunteers repeat tests five times. Study-5 tested MedDrive's responsiveness to alcohol in a randomised, double-blinded, placebo, crossover, dose-response validation trial including 20 young healthy volunteers. Results: Instructions were well understood and accepted by all senior drivers. Measures of visual processing (Task1) showed better performances than the UFOV in detecting MCI (ROC 0.770 vs. 0.620; p=0.048). MedDrive was capable of explaining 43.4% of changes occurring with natural cognitive decline. In young healthy drivers, learning effects became negligible from the third session onwards for all tasks except for dual tasking (ICC=0.769). All measures except alerting and orientation gain were affected by blood alcohol concentrations. Finally, MedDrive was able to explain 29.3% of potential causes of swerving on the driving simulator. Discussion and conclusions: MedDrive reveals improved performances compared to existing computed neuropsychological tasks. It shows promising results both for clinical and research purposes.

From deep seated slope deformation to rock avalanche: Destabilization and transportation models of the Sierre landslide (Switzerland)

Sackung is a widespread post-glacial morphological feature affecting Alpine mountains and creating characteristic geomorphological expression that can be detected from topography. Over long time evolution, internal deformation can lead to the formation of rapidly moving phenomena such as a rock-slide or rock avalanche. In this study, a detailed description of the Sierre rock-avalanche (SW Switzerland) is presented. This convex-shaped postglacial instability is one of the larger rock-avalanche in the Alps, involving more than 1.5 billion m3 with a run-out distance of about 14 km and extremely low Fahrböschung angle. This study presents comprehensive analyses of the structural and geological characteristics leading to the development of the Sierre rock-avalanche. In particular, by combining field observations, digital elevation model analyses and numerical modelling, the strong influence of both ductile and brittle tectonic structures on the failure mechanism and on the failure surface geometry is highlighted. The detection of pre-failure deformation indicates that the development of the rock avalanche corresponds to the last evolutionary stage of a pre-existing deep seated gravitational slope instability. These analyses accompanied by the dating and the characterization of rock avalanche deposits, allow the proposal of a destabilization model that clarifies the different phases leading to the development of the Sierre rock avalanche.

Measuring cytoskeleton and cellular membrane mechanical properties by atomic force microscopy.

Atomic force microscope is an invaluable device to explore living specimens at a nanometric scale. It permits to image the topography of the sample in 3D, to measure its mechanical properties and to detect the presence of specific molecules bound on its surface. Here we describe the procedure to gather such a data set on living macrophages.

Validation study of the French version of the observer-rater scales measuring coping and cognitive errors (CE-CAP) on a non-clinical population

This study examined the validity and reliability of the French version of two observer-rated measures developed to assess cognitive errors (cognitive errors rating system [CERS]) [6] and coping action patterns (coping action patterns rating system [CAPRS]) [22,24]. The CE measures 14 cognitive errors, broken down according to their valence positive or negative (see the definitions by A.T. Beck), and the CAP measures 12 coping categories, based on an comprehensive review literature, each broken down into three levels of action (affective, behavioural, cognitive). Thirty (N = 30) subjects recruited in a community sample participated in the study. They were interviewed according to a standardized clinical protocol: these interviews were transcribed and analysed with both observer-rated systems. Results showed that the inter-rater reliability of the two measures is good and that their internal validity is satisfactory, due to a non-significant canonical correlation between CAP and CE. With regard to discriminant validity, we found a non-significant canonical correlation between CAPRS and CISS, one of most widely used self-report questionnaire measuring coping. The same can be said for the correlation with a self-report questionnaire measuring symptoms (SCL-90-R). These results confirm the absence of confounds in the assessment of cognitive errors and of coping as assessed by these observer-rated scales and add an argument in favour of the French validation of the CE-CAP rating scales. (C) 2010 Elsevier Masson SAS. All rights reserved.

Fécondation in vitro: intérêt et désavantage du remboursement par l'assurance maladie en Suisse [In-vitro fertilization: advantage and disadvantage of covering the costs of IVF/ICSI by the health insurance in Switzerland]

In-vitro fertilization: advantage and disadvantage of covering the costs of IVF/CSI by the health insurance in Switzerland The reimbursement of certain infertility treatments (stimulation with/without insemination) whereas IVF/ICSI is not leads patients with an indication of IVF to prefer treatments of low efficacy. The costs of multiple pregnancies issued by reimbursed or non-reimbursed fertility treatments are paid by the society. There should be measures to reduce these costs and to take the money used today to pay the complications of infertility treatments to reimburse IVF. The efficacy of such a system (single embryo transfer) has been proven in Belgium since several years. The dangers of complete reimbursement (IVF treatment in cases without any chances of success, only because it is for free) can be avoided by an Efficacy and Safety Board.

A validated assay for measuring doxorubicin in biological fluids and tissues in an isolated lung perfusion model: matrix effect and heparin interference strongly influence doxorubicin measurements.

Doxorubicin is an antineoplasic agent active against sarcoma pulmonary metastasis, but its clinical use is hampered by its myelotoxicity and its cumulative cardiotoxicity, when administered systemically. This limitation may be circumvented using the isolated lung perfusion (ILP) approach, wherein a therapeutic agent is infused locoregionally after vascular isolation of the lung. The influence of the mode of infusion (anterograde (AG): through the pulmonary artery (PA); retrograde (RG): through the pulmonary vein (PV)) on doxorubicin pharmacokinetics and lung distribution was unknown. Therefore, a simple, rapid and sensitive high-performance liquid chromatography method has been developed to quantify doxorubicin in four different biological matrices (infusion effluent, serum, tissues with low or high levels of doxorubicin). The related compound daunorubicin was used as internal standard (I.S.). Following a single-step protein precipitation of 500 microl samples with 250 microl acetone and 50 microl zinc sulfate 70% aqueous solution, the obtained supernatant was evaporated to dryness at 60 degrees C for exactly 45 min under a stream of nitrogen and the solid residue was solubilized in 200 microl of purified water. A 100 microl-volume was subjected to HPLC analysis onto a Nucleosil 100-5 microm C18 AB column equipped with a guard column (Nucleosil 100-5 microm C(6)H(5) (phenyl) end-capped) using a gradient elution of acetonitrile and 1-heptanesulfonic acid 0.2% pH 4: 15/85 at 0 min-->50/50 at 20 min-->100/0 at 22 min-->15/85 at 24 min-->15/85 at 26 min, delivered at 1 ml/min. The analytes were detected by fluorescence detection with excitation and emission wavelength set at 480 and 550 nm, respectively. The calibration curves were linear over the range of 2-1000 ng/ml for effluent and plasma matrices, and 0.1 microg/g-750 microg/g for tissues matrices. The method is precise with inter-day and intra-day relative standard deviation within 0.5 and 6.7% and accurate with inter-day and intra-day deviations between -5.4 and +7.7%. The in vitro stability in all matrices and in processed samples has been studied at -80 degrees C for 1 month, and at 4 degrees C for 48 h, respectively. During initial studies, heparin used as anticoagulant was found to profoundly influence the measurements of doxorubicin in effluents collected from animals under ILP. Moreover, the strong matrix effect observed with tissues samples indicate that it is mandatory to prepare doxorubicin calibration standard samples in biological matrices which would reflect at best the composition of samples to be analyzed. This method was successfully applied in animal studies for the analysis of effluent, serum and tissue samples collected from pigs and rats undergoing ILP.

Measuring spiritual well-being in older rehabilitation patients using the facit-sp

Objectives: To determine psychometric properties of the Functional Assessment of Chronic Illness Therapy-Spiritual well-being (FACIT-Sp) in a cohort of older patients admitted to rehabilitation. Method: Patients aged 65+, with MMSE score>19, admitted consecutively over 6 months in post-acute rehabilitation were enrolled (N=144, 81.27.2 years, 68.8% women). Data on medical, functional, and mental status were systematically collected upon admission. Spiritual well-being was assessed within 3 days after admission using the FACIT-Sp (12 items, score from 0 to 48, high spiritual well-being defined as a score ≥36) and the single question "Are you at peace?" (score from 0 to 10 on a visual analog scale). Results: FACIT-Sp scores ranged from 7 to 44(mean=29.87.7). Overall, 24.3% of the patients had high spiritual well-being. Internal consistency was optimal for total score (Cronbach's alpha =0.85). Itemto- total correlations were all significant, ranging from 0.28 to 0.73. A confirmatory factorial analysis yielded a 2-factor solution, consistent with Meaning and Faith proposed subscales and accounting for 52% of the variance . FACIT-Sp total score correlated positively with the question «Are you at peace ?» (Spearman's rho 0.49, P<.001) and negatively with depressive symptoms (Spearman's rho -0.37, P<.001), confirming FACIT-Sp validity. Compared to the others, patients with higher spiritual well-being had significantly better function at admission (Barthel's score 74.817.1 vs 68.514.1, P=.014). Conclusions: The FACIT-Sp remains a reliable and valid measure to assess spiritual well-being in older patients undergoing rehabilitation. The relatively low proportion of patients with high spiritual well-being deserves further investigation.

Measuring ecological niche overlap from occurrence and spatial environmental data

1. Aim - Concerns over how global change will influence species distributions, in conjunction with increased emphasis on understanding niche dynamics in evolutionary and community contexts, highlight the growing need for robust methods to quantify niche differences between or within taxa. We propose a statistical framework to describe and compare environmental niches from occurrence and spatial environmental data.¦2. Location - Europe, North America, South America¦3. Methods - The framework applies kernel smoothers to densities of species occurrence in gridded environmental space to calculate metrics of niche overlap and test hypotheses regarding niche conservatism. We use this framework and simulated species with predefined distributions and amounts of niche overlap to evaluate several ordination and species distribution modeling techniques for quantifying niche overlap. We illustrate the approach with data on two well-studied invasive species.¦4. Results - We show that niche overlap can be accurately detected with the framework when variables driving the distributions are known. The method is robust to known and previously undocumented biases related to the dependence of species occurrences on the frequency of environmental conditions that occur across geographic space. The use of a kernel smoother makes the process of moving from geographical space to multivariate environmental space independent of both sampling effort and arbitrary choice of resolution in environmental space. However, the use of ordination and species distribution model techniques for selecting, combining and weighting variables on which niche overlap is calculated provide contrasting results.¦5. Main conclusions - The framework meets the increasing need for robust methods to quantify niche differences. It is appropriate to study niche differences between species, subspecies or intraspecific lineages that differ in their geographical distributions. Alternatively, it can be used to measure the degree to which the environmental niche of a species or intraspecific lineage has changed over time.

Measuring surface potential changes on leaves.

We provide here a detailed protocol for studying the changes in electrical surface potential of leaves. This method has been developed over the years by plant physiologists and is currently used in different variants in many laboratories. The protocol records surface potential changes to measure long-distance electrical signals induced by diverse stimuli such as leaf wounding or current injection. This technique can be used to determine signaling speeds, to measure the connectivity between different plant organs and-by exploiting mutant plants-to identify transporters and ion channels involved in electrical signaling. The approach can be combined with the analysis of mRNA expression and of metabolite concentrations to correlate electrical signaling to specific physiological events. We describe how to use this protocol on Arabidopsis, looking at the effects of leaf wounding; however, it is broadly applicable to other plants and can be used to study other aspects of plant physiology. After wound infliction, surface potential recording takes ∼20 min per plant.

Measuring alcohol-related consequences in school surveys: alcohol-attributable consequences or consequences with students' alcohol attribution.

In alcohol epidemiology surveys, there is a tradition of measuring alcohol-related consequences using respondents' attribution of alcohol as the cause. The authors aimed to compare the prevalence and frequency of self-attributed consequences to consequences without self-attribution using alcohol-attributable fractions (AAF). In 2007, a total of 7,174 Swiss school students aged 13-16 years reported the numbers of 6 alcohol-related adverse consequences (e.g., fights, injuries) they had incurred in the past 12 months. Consequences were measured with and without attribution of alcohol as the cause. The alcohol-use measures were frequency and volume of drinking in the past 12 months and number of risky single-occasion (> or =5 drinks) drinking episodes in the past 30 days. Attributable fractions were derived from logistic (> or =1 incident) and Poisson (number of incidents) regression analyses. Although relative risk estimates were higher when alcohol-attributed consequences were compared with nonattributed consequences, the use of AAFs resulted in more alcohol-related consequences (10,422 self-attributed consequences vs. 24,520 nonattributed consequences determined by means of AAFs). The likelihood of underreporting was higher among drinkers with intermediate frequencies than among either rare drinkers or frequent drinkers. Therefore, the extent of alcohol-related adverse consequences among adolescents may be underestimated when using self-attributed consequences, because of differential attribution processes, especially among infrequent drinkers.