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Bartolini G.,University of Cagliary | Levant A.,Tel Aviv University | Plestan F.,University of Cagliary | Taleb M.,Ecole Centrale Nantes | Punta E.,CNR Institute of Intelligent Systems for Automation
IMA Journal of Mathematical Control and Information | Year: 2013

Adaptive sliding-mode strategies of first and second sliding orders are developed for single-input singleoutput systems of the first and second relative degrees, respectively. Since the only concrete known uncertainty bounds are assumed to be the upper bounds of logarithmic derivatives, no standard slidingmode technique can solve the problem. © The authors 2012. Source

Luck T.,University of Leipzig | Luppa M.,University of Leipzig | Angermeyer M.C.,Center for Public Mental Health | Angermeyer M.C.,University of Cagliary | And 3 more authors.
Psychological Medicine | Year: 2011

Background Early diagnosis of dementia requires knowledge about associated predictors. The aim of this study was to determine the impact of mild cognitive impairment (MCI) and impairment in instrumental activities of daily living (IADL) on the time to an incident dementia diagnosis. Method Data were derived from the Leipzig Longitudinal Study of the Aged (LEILA75+), a population-based study of individuals aged ≥75 years. Kaplan-Meier survival analysis was used to determine time to incident dementia. Cox proportional hazards models were applied to determine the impact of MCI and IADL impairment on the time to incident dementia. Results In total, 180 (22.0%) of 819 initially dementia-free subjects developed dementia by the end of the study. Mean time to incident dementia was 6.7 years [95% confidence interval (CI) 6.5-6.9]. MCI combined with IADL impairment was associated with a higher conversion rate to dementia, a shorter time to clinically manifest diagnosis and a lower chance of reversibility to cognitive normal. The highest risk for a shorter time to incident dementia was found for amnestic MCI combined with IADL impairment. The mean time to incident dementia was 3.7 years (95% CI 2.9-4.4) and thus half as long as in subjects without MCI and IADL impairment. Conclusions Subjects with MCI and IADL impairment constitute a high-risk population for future dementia. The consideration of both - MCI and IADL impairment - might help to improve the prediction of dementia. © Cambridge University Press 2010. Source

Then F.S.,University of Leipzig | Luppa M.,University of Leipzig | Schroeter M.L.,University of Leipzig | Schroeter M.L.,Max Planck Institute for Human Cognitive and Brain Sciences | And 4 more authors.
PLoS ONE | Year: 2013

Background:The high incidence of cognitive impairments in the aging population together with the challenges it imposes on health systems raise the question of what effect working life has on cognitive abilities. Animal models have demonstrated that so called enriched environments protect against neurodegenerative diseases, such as dementia. The aim was to investigate the impact of enriched environment at work on the incidence of dementia.Methods:The Leipzig Longitudinal Study of the Aged (LEILA 75+) is an ongoing representative population cohort study that examines cognitive functioning and dementia in individuals aged 75 years and older. The participants' occupational information was matched to O*NET SOC codes and the relevant job descriptors were used to create occupational context indices describing enriched environment at work.Results:Results of logistic regression modeling suggest that a higher level of the index Executive was associated with a lower risk of incident dementia (odds ratio = 0.61, 95% confidence interval = 0.47-0.79, p<0.001). Adjustment for various confounders did not alter the association. The cognitive stimulation indices were only significant in univariate analysis. The Novelty-index remained non-significant.Conclusions:The results suggest that occupational contexts enriched with independent planning/performance of work tasks might decrease the risk of developing dementia. A protective effect of enriched environment at work in general, namely high cognitive stimulation or confrontation with new tasks, could not be confirmed by the results. © 2013 Then et al. Source

Zieger M.,University of Leipzig | Luppa M.,University of Leipzig | Matschinger H.,University of Leipzig | Meisel H.J.,Berufsgenossenschaftliche Kliniken Bergmannstrost | And 6 more authors.
Social Psychiatry and Psychiatric Epidemiology | Year: 2011

Purpose At present only a small number of studies have investigated psychiatric comorbidity in disc surgery patients. Objectives of this study are (1) to examine the prevalence rate of comorbid affective, anxiety, and substance- related disorders in nucleotomy patients in comparison to the German general population and (2) to investigate associations between psychiatric comorbidity and socio-demographic and illness-related characteristics. Methods The study refers to 349 consecutive disc surgery patients (response rate 87%) between the age of 18 and 55 years.Thefinal study sample consists of 239 lumbar and 66 cervical nucleotomy patients. Face-to-face interviews were conducted approximately 3.45 days (SD 3.170) after disc surgery, during hospital stay. Psychiatric comorbidity was assessed by means of the Composite International Diagnostic Interview (CIDI-DIA-X). The corresponding data of the German general population were derived from the German National Health Interview and Examination Survey (GHS). Results 12-Month prevalence rates of any affective, anxiety or substance-related disorders range between 33.7% in cervical and 23.5% in lumbar disc surgery patients. Four-week prevalence rates of any affective, anxiety or substance disorder vary between 13.2% in cervical and 14.0% in lumbar nucleotomy patients. Disc surgery patients suffer more often from affective disorders and illicit substance abuse than the general population. Significant associations were found between psychiatric comorbidity and gender, as well as pain intensity. Conclusions Disc surgery patients show a higher risk to suffer from mental disorders than the general population. The assessment of psychiatric distress and the assistance by mental health professionals should be considered during hospital and rehabilitation treatment. © The Author(s) 2010. Source

Cerdan O.,Bureau de Recherches Geologiques et Minieres | Govers G.,Catholic University of Leuven | Le Bissonnais Y.,IRD Montpellier | Van Oost K.,University of Leuven La Neuve | And 14 more authors.
Geomorphology | Year: 2010

An extensive database of short to medium-term erosion rates as measured on erosion plots in Europe under natural rainfall was compiled from the literature. Statistical analysis confirmed the dominant influence of land use and cover on soil erosion rates. Sheet and rill erosion rates are highest on bare soil; vineyards show the second highest soil losses, followed by other arable lands (spring crops, orchards and winter crops). A land with a permanent vegetation cover (shrubs, grassland and forest) is characterised by soil losses which are generally more than an order of magnitude lower than those on arable land. Disturbance of permanent vegetation by fire leads to momentarily higher erosion rates but rates are still lower than those measured on arable land. We also noticed important regional differences in erosion rates. Erosion rates are generally much lower in the Mediterranean as compared to other areas in Europe; this is mainly attributed to the high soil stoniness in the Mediterranean. Measured erosion rates on arable and bare land were related to topography (slope steepness and length) and soil texture, while this was not the case for plots with a permanent land cover. We attribute this to a fundamental difference in runoff generation and sediment transfer according to land cover types.On the basis of these results we calculated mean sheet and rill erosion rates for the European area covered by the CORINE database: estimated rill and interrill erosion rates are ca. 1.2tha-1year-1 for the whole CORINE area and ca. 3.6tha-1year-1 for arable land. These estimates are much lower than some earlier estimates which were based on the erroneous extrapolation of small datasets. High erosion rates occur in areas dominated by vineyards, the hilly loess areas in West and Central Europe and the agricultural areas located in the piedmont areas of the major European mountain ranges. © 2010 Elsevier B.V. Source

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