Improvement of Early Recognition of Attacks in Karate Kumite Due to Training in Virtual Reality

In a Virtual Reality training, young karate athletes divided in two groups (intervention vs. control group) responded to attacks of a virtual opponent. For the analysis, the first reaction of the responding karate athletes was detected. From that point three reaction times were subtracted to analyze the attack of the virtual opponent at the time of the recognition of the real athlete. The attacks were divided into four movement stages. Analysis of Variance (ANOVAs) with repeated measures and estimation of effect sizes as well as Bonferroni post-hoc tests were applied to calculate interactions between time (PRE to POST), group (intervention vs. control) and reaction time (150 ms vs. 255 ms vs. 370 ms). We found significant effects for time and time x group interactions for the attacks Gyaku-Zuki and Kizami-Zuki as well as an effect for time x reaction time in Gyaku-Zuki (all p < 0.001), but no significant effects for time x group x reaction time in both attacks (p > 0.05). Paired t-tests showed significant improvements in attack recognition from PRE to POST for the intervention group, but not for the control group. At the pretest all athletes responded to late movement stages (extension of the pushing arm) while the intervention group responded to early movement stages (preparing steps and reduction of distance before the attack) at the posttest due to the Virtual Reality training. Early steps for the preparation of the attack and the reduction of distance seem to be important signals for attack recognition

A Model Rock Biofilm Growing in Percolation Columns

Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterized by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonization of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1–6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 μM thiamine-hydrochloride (90 μL min−1) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: (i) analysing the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragments/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favored a dissolution- reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analyzed

Comparison of proteomic responses as global approach to antibiotic mechanism of action elucidation

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology

Consideration of bioavailability in the effect directed analysis of contaminated sediment samples

The scope of the presented PhD thesis is on the incorporation of bioavailability into effect directed analysis (EDA) of contaminated sediment samples. EDA has been successfully applied in the last years to identify key toxicants in environmental samples. One of the major challenges in EDA is how to consider bioavailability of investigated chemicals. By using crude sediment extracts and solvent dosing the ecotoxicological effects may be overestimated and prioritisation of fractions may be biased. The equilibrium approach is often used for bioavailability estimation. A new dosing technique has been developed to simulate the partitioning between sediment particles and the surrounding aqueous phase. Costumer made stirrer bars (SR) consisting of poly(dimethylsiloxane) were suggested as a novel tool and evaluated for the application in a cell multiplication inhibition test with green algae Scenedesmus vacuolatus using a set of model compounds covering a broad range of physico-chemical properties. The SRs have been shown to have a high loading capacity and in general a fast achievement of equilibrium. This subsequent delivery compensates for possible losses due to e.g. adsorption or evaporation and leads to constant concentrations. Good dose-response curves were achieved using this method. To measure and monitor the aqueous concentration during the bioassay a pre-equilibrium solid phase extraction (SPME) method was developed and validated. This method is non depletive and thus does not change the concentration in the sample. Evaluation of the limit of detection (LOQ) confirms that sufficiently low concentrations compared to EC50 concentrations observed in the algae assay can be measured. The presence of the algae has no observable overall effect on the concentration measurements. Therefore, bio fouling of the SPME fibers and enhanced uptake kinetics due to the presence of another strong adsorbing phase (algae) do not play an important role in this system. This SPME method was also used for determination of algae growth medium partition coefficients. The two developed methods were applied in EDA studies of contaminated sediment samples. The sediment extracts from hot spots from the Elbe River basin were fractionated using a multistep normal phase HPLC method. The fractions were dosed to the algae assay either by conventional solvent dosing via dimethylsulfoxid (DMSO) or by using the partition based dosing method using SR. The results reveal that the consideration of the bioavailability has a strong influence on the prioritization of fractions and that the differences between the three sediment samples is less pronounced than between the two dosing techniques. Dosing with DMSO identifies mainly fractions, in which polyaromatic hydrocarbons (PAHs) and more polar compounds are expected to elute, as most toxic fractions, while for dosing with SRs the fractions co-eluting with polar compounds are the most toxic ones. From the three sediments one from a tributary from the Elbe River was chosen. As second fraction step a reversed phase HPLC was used to fractionate the most toxic fraction from the first step. Sub-fractions showing highest toxicity in the bioassay with green algae were analyzed by GC-MS. The identity of the compounds was confirmed with pure standards. Effect confirmation was based on the effects of artificial mixtures with the same composition and concentrations as the sub-fractions. For DMSO dosing PAHs and hexadecanol were confirmed as toxicants, while for the new dosing technique more polar compounds as e.g. triclosane and benz[c]acridine were confirmed. These results support the need for increasing environmental realism in EDA to identify those toxicants that pose major hazards

Calibration and field application of passive sampling for episodic exposure to polar organic pesticides in streams

Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore(TM) styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d(-1) and time-weighted average (TWA) concentrations from 0.05 to 2.11 mu g/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides. (C) 2014 Elsevier Ltd. All rights reserved

KaraKter: An autonomously interacting Karate Kumite character for VR-based training and research

We report on the creation of an autonomous Karate Kumite character (KaraKter) that can be used for VR based training and research in Karate Kumite. For the real time interaction with KaraKter, a human athlete is tracked in a virtual environment. KaraKter moves in Karate specific ways, approaches the athlete and realizes adequate attacks depending on the behavior of the human. KaraKter passed tests on functionality and performance and has been evaluated by high ranking Karate experts. The evaluation showed that the athletes accept KaraKter as an actual opponent. All experts rated the system to be useful in the training of Karate Kumite