Reproducing or dispersing? Using trait based habitat templet models to analyse Orthoptera response to flooding and land use

Habitat templet theory predicts that habitat provides the templet on which evolution shapes species’ multiple traits and thus their characteristic life-history strategies. By analysing entire trait communities (multiple species and traits) in this framework we can enhance our understanding of how species composition changes as environmental constraints vary across the landscape. Here, we study multiple traits of floodplain Orthoptera communities under the influence of two different sources of disturbance, land use and seasonal flooding.The application of two recently developed statistical techniques - qualitative RLQ analysis and subsequent fourth-corner permutation tests - revealed two different life history strategies in Orthoptera as a response to ecological disturbances, resulting from land use management and seasonal flooding. Orthoptera species seem to have developed two complementary strategies: (i) the high active dispersal-low reproduction strategy in intensive land use situations and (ii) the high passive dispersal-high reproduction strategy in areas with high flood disturbance. Disturbance gradients act as trait filters allowing only particular trait combinations i.e. species with particular preadaptations to survive, whereas others go regionally extinct. Reproduction and dispersal capacity seem to be inversely associated with the disturbance gradients. Ovariole number, taken as the measure for reproduction, showed significant phylogenetic signal, which could potentially confound this relationship. Nonetheless, RLQ analyses coupled with fourth-corner permutation tests proved a powerful tool to reveal and disentangle different evolutionary strategies.     

Transformation of occupational health in the Czech Republic: Challenge for education and training

The establishment of occupational health services entrusted with essentially preventive tasks was enacted in the Czech Republic only in 1991. A major obstacle to the implementation of this legal provision is the limited number of specialists in occupational medicine, less than 250 for a total labour force of about 5 million. Enhanced education and training of further occupational physicians is needed, the resources being general practicioners having expertise with basic occupational health care in various sectors of economic activities. In order to meet the EC standards for the specialty, cooperation within the framework of EASOM is highly desirable.     

Behavior of sartans (antihypertensive drugs) in wastewater treatment plants,their occurrence and risk for the aquatic environment

Pharmaceuticals and other anthropogenic trace contaminants reach wastewaters and are often not satisfactorily eliminated in sewage treatment plants. These contaminants and/or their degradation products may reach surface waters, thus influencing aquatic life. In this study, the behavior of five different antihypertonic pharmaceuticals from the sartan group (candesartan, eprosartan, irbesartan, olmesartan and valsartan) is investigated in lab-scale sewage plants. The elimination of the substances with related structures varied broadly from 17 % for olmesartan up to 96 % for valsartan. Monitoring data for these drugs in wastewater effluents of six different sewage treatment plants (STPs) in Bavaria, and at eight rivers, showed median concentrations for, e.g. valsartan of 1.1 and 0.13 μg L^?1, respectively. Predicted environmental concentrations (PEC) were calculated and are mostly consistent with the measured environmental concentrations (MEC). The selected sartans and the mixture of the five sartans showed no ecotoxic effects on aquatic organisms in relevant concentrations. Nevertheless, the occurrence of pharmaceuticals in the environment should be reduced to minimize the risk of their distribution in surface waters, ground waters and bank filtrates used for drinking water.     

Dressler’s theory for curved topography flows: iterative derivation,transcritical flow solutions and higher-order wave-type equations

The Dressler equations are a system of two non-linear partial differential equations for shallow fluid flows over curved topography. The theory originated from an asymptotic stretching method formulating the equations of motion in terrain-fitted curvilinear coordinates. Apparently, these equations failed to produce a transcritical flow profile changing from sub- to supercritical flow conditions. Further, wave-like motions over a flat bottom are excluded because the bed-normal velocity component is not accounted for. However, the theory was found relevant for several environmental flow problems including density currents over mountains and valleys, seepage flow in hillslope hydrology, the development of antidunes, the formation of geological deposits from hyper-concentrated flows, and shallow-water flow modeling in hydraulics. In this work, Dressler’s theory is developed in an alternative way by a systematic iteration of the stream and potential functions in terrain-fitted coordinates. The first iteration was found to be the former Dressler’s theory, whereas a second iteration of the governing equations results in velocity components generalizing Dressler’s theory to wave-like motion. Dressler’s first-order theory produces a transcritical flow solution over topography only if the total head is fixed by a minimum value of the specific energy at the transition point. However, the theory deviates from measurements under subcritical flow conditions, given that the bed-normal velocity component is significant. A second iteration to the velocity field was used to produce a second-order differential equation that resembles the cnoidal-wave theory. It accurately produces flow over an obstacle including the critical point and the minimum specific energy as part of the numerical solution. The new cnoidal-wave model compares well with the theory of a Cosserat surface for directed fluid sheets, whereas the Saint-Venant theory appears to be poor.