Automatic Generation of Randomized Trial Sequences for Priming Experiments

In most psychological experiments, a randomized presentation of successive displays is crucial for the validity of the results. For some paradigms, this is not a trivial issue because trials are interdependent, e.g., priming paradigms. We present a software that automatically generates optimized trial sequences for (negative-) priming experiments. Our implementation is based on an optimization heuristic known as genetic algorithms that allows for an intuitive interpretation due to its similarity to natural evolution. The program features a graphical user interface that allows the user to generate trial sequences and to interactively improve them. The software is based on freely available software and is released under the GNU General Public License

Inhibition in the dynamics of selective attention: an integrative model for negative priming

We introduce a computational model of the negative priming (NP) effect that includes perception, memory, attention, decision making, and action. The model is designed to provide a coherent picture across competing theories of NP. The model is formulated in terms of abstract dynamics for the activations of features, their binding into object entities, their semantic categorization as well as related memories and appropriate reactions. The dynamic variables interact in a connectionist network which is shown to be adaptable to a variety of experimental paradigms. We find that selective attention can be modeled by means of inhibitory processes and by a threshold dynamics. From the necessity of quantifying the experimental paradigms, we conclude that the specificity of the experimental paradigm must be taken into account when predicting the nature of the NP effect

Identity Negative Priming: A Phenomenon of Perception, Recognition or Selection?

The present study addresses the problem whether negative priming (NP) is due to information processing in perception, recognition or selection. We argue that most NP studies confound priming and perceptual similarity of prime-probe episodes and implement a color-switch paradigm in order to resolve the issue. In a series of three identity negative priming experiments with verbal naming response, we determined when NP and positive priming (PP) occur during a trial. The first experiment assessed the impact of target color on priming effects. It consisted of two blocks, each with a different fixed target color. With respect to target color no differential priming effects were found. In Experiment 2 the target color was indicated by a cue for each trial. Here we resolved the confounding of perceptual similarity and priming condition. In trials with coinciding colors for prime and probe, we found priming effects similar to Experiment 1. However, trials with a target color switch showed such effects only in trials with role-reversal (distractor-to-target or target-to-distractor), whereas the positive priming (PP) effect in the target-repetition trials disappeared. Finally, Experiment 3 split trial processing into two phases by presenting the trial-wise color cue only after the stimulus objects had been recognized. We found recognition in every priming condition to be faster than in control trials. We were hence led to the conclusion that PP is strongly affected by perception, in contrast to NP which emerges during selection, i.e., the two effects cannot be explained by a single mechanism

Towards Biochar and Hydrochar Engineering—Influence of Process Conditions on Surface Physical and Chemical Properties, Thermal Stability, Nutrient Availability, Toxicity and Wettability

The impact of conversion process parameters in pyrolysis (maximum temperature, inert gas flow rate) and hydrothermal carbonization (maximum temperature, residence time and post-washing) on biochar and hydrochar properties is investigated. Pine wood (PW) and corn digestate (CD), with low and high inorganic species content respectively, are used as feedstock. CD biochars show lower H/C ratios, thermal recalcitrance and total specific surface area than PW biochars, but higher mesoporosity. CD and PW biochars present higher naphthalene and phenanthrene contents, respectively, which may indicate different reaction pathways. High temperatures (>500 °C) lead to lower PAH (polycyclic aromatic hydrocarbons) content (<12 mg/kg) and higher specific surface area. With increasing process severity the biochars carbon content is also enhanced, as well as the thermal stability. High inert gas flow rates increase the microporosity and wettability of biochars. In hydrochars the high inorganic content favor decarboxylation over dehydration reactions. Hydrochars show mainly mesoporosity, with a higher pore volume but generally lower specific surface area than biochars. Biochars present negligible availability of NO −3 and NH +4 , irrespective of the nitrogen content of the feedstock. For hydrochars, a potential increase in availability of NO −3 , NH +4 , PO 3−4 , and K + with respect to the feedstock is possible. The results from this work can be applied to “engineer” appropriate biochars with respect to soil demands and certification requirements

Einfluss von Ozon, CO2 und Trockenstress auf das Wachstum und die Pollenproduktion der Beifuß-Ambrosie (Ambrosia artemisiifolia)

Klimaveränderungen beeinflussen das pflanzliche Wachstum und können auch einen Einfluss auf den Pollen haben. Wichtige Faktoren sind dabei erhöhte CO2-Konzentrationen, Trockenstress und Schadstoffbelastungen. Die Pollen der Beifuß-Ambrosie gehören mit zu den stärksten Allergie-Auslösern und beeinflussen die menschliche Gesundheit. In dieser Studie wurde die Beifuß-Ambrosie über die gesamte Vegetationsperiode erhöhten CO2- (700 ppm) und Ozon- (80 ppb) Konzentrationen ausgesetzt. Ferner wurde der Einfluss von Trockenstress unter unterschiedlichen CO2-Konzentrationen untersucht. Erhöhtes CO2 und Trockenstress hatten keinen Einfluss auf die Größe, Form und Oberflächenstruktur des Pollens. Bezüglich morphologischer Parameter resultierte erhöhtes CO2 in einer Zunahme des Stängelwachstums und der Hauptinfloreszenz, sowie vermehrter Pollenproduktion. Trockenstress führte zu einem reduzierten Wachstum des Stängels und der Hauptinfloreszenz und verringerter Pollen-Ausbeute. Erhöhte Ozon-Werte führten tendenziell zu einer geringeren, statistisch jedoch nicht signifikant veränderten Pollenausbeute. Diese Ergebnisse weisen darauf hin, dass Klimaveränderungen die Entwicklung von Ambrosia-Pollen beeinflussen und dadurch auch die öffentliche Gesundheit beeinträchtigen.Stichwörter: Allergie, Infloreszenz, Klimawandel, Luftschadstoff, Stängel, VegetationsperiodeEffects of ozone, CO2 and drought stress on the growth and pollen production of common ragweed (Ambrosia artemisiifolia)Climate change will affect the growth of plants and may also influence the production of pollen. The important factors influencing climate change are increased CO2 concentrations, drought and air pollution. Common ragweed pollen is known to be strongly allergenic, thereby affecting human health. In this study, common ragweed plants were grown over an entire vegetation period under conditions of twice the ambient level of CO2 (700 ppm) and ozone (80 ppm), respectively. Furthermore, the effect of soil drought combined with different CO2 levels was investigated. Scanning electron microscopy showed no change in surface morphology and size of CO2- and drought-treated pollen. Regarding morphological parameters, elevated CO2 resulted in an increased length of the stem and the main inflorescence and higher pollen yields, whereas drought reduced the stem and inflorescence lengths and resulted in a lower pollen yield, a result that was mitigated by elevated CO2. Twice the ambient level of ozone tends to result in a reduced pollen yield. However, this was not statistically significant. These findings support the idea that the conditions of climate change will influence the development of common ragweed pollen, thereby affecting public health.Keywords: Allergy, air pollution, inflorescence, climate change, stem, vegetation perio

Vergleichende funktionale Untersuchungen des Hitze-Capsaicin-Rezeptors (TRPV1) und des Kälte-Menthol-Rezeptors (TRPM8) in rekombinanten und nativen Zellsystemen (verwendete Spezies Mensch, Ratte und Maus)

In der vorliegenden Arbeit wurden via FLIPR und Ca2+-Imaging die pH-Abhängigkeit von Capsaicin, NADA und ANA herausgestellt. Es zeigte sich eine Potenzierung bei leicht sauren pH-Werten. Eine am C-Terminus trunkierte TRPV1-Variante wurde entdeckt und es wurde gezeigt, dass sie weder funktional noch dominant negativ aktiv ist. Der TRPM8 wurde bezüglich seiner Temperaturabhängigkeit charakterisiert. Es konnten zehn neue TRPM8-Agonisten in einer Duftsubstanzbibliothek und unter Menthol-ähnlichen Derivaten identifiziert werden. Die TRPV1-Antagonisten, BCTC, thio-BCTC und Capsazepin konnten als erste TRPM8-Antagonisten identifiziert und charakterisiert werden. Eine Schild-Plot Analyse ergab, dass BCTC und Capsazepin, im Gegensatz zur Wirkung am TRPV1, nicht einfach kompetetiv die Stimulation des TRPM8 durch Menthol und Icilin inhibieren. Anders als beim TRPV1, der durch sauren pH sensitisiert wurde, führte eine Senkung des pH-Wertes zu einer Reduktion der Aktivierbarkeit des TRPM8

Response-retrieval in identity negative priming is modulated by temporal discriminability

Reaction times to previously ignored information are often delayed, a phenomenon referred to as negative priming (NP). Rothermund et al. (2005) proposed that NP is caused by the retrieval of incidental stimulus-response associations when consecutive displays share visual features but require different responses. In two experiments we examined whether the features (color, shape) that reappear in consecutive displays, or their level of processing (early-perceptual, late-semantic) moderate the likelihood that stimulus-response associations are retrieved. Using a perceptual matching task (Experiment 1), NP occurred independently of whether responses were repeated or switched. Only when implementing a semantic-matching task (Experiment 2), negative priming was determined by response-repetition as predicted by response-retrieval theory. The results can be explained in terms of a task-dependent temporal discrimination process (Milliken et al., 1998): Response-relevant features are encoded more strongly and/or are more likely to be retrieved than irrelevant features

Effusion Cooled Combustor Liner Tiles with Modern Cooling Concepts: A Comparative Experimental Study

Advanced combustion techniques in aero engines require highly effective cooling schemes of combustor liners. One Parameter affecting the cooling performance is the geometry of the cooling holes themselves. So far, the freedom in the design of cooling holes was limited due to the manufacturing techniques. With emerging additive manufacturing methods, e.g. Direct Metal Laser Sintering, however, the geometry of the cooling holes is virtually unlimited. Especially the entrance and the curvature of the cooling holes determines the through-flow of the hole and consequently the cooling performance of the ejected cooling film. In this study a set of combustor liner tiles with two innovative and four traditional cooling hole geometries will be analyzed and compared to each other in terms of cooling performance. The innovative geometries have bent cooling holes with a nearly horizontal outlet. All specimens have the same cooling hole pattern. The cooling performance is determined by comparing the total cooling effectiveness for a given pressure difference across the combustor liner tiles. The coolant mass flow rate is gained from experimentally determined discharge coefficients for the respective pressure difference. The first set of measurements is conducted in an atmospheric open-loop test rig at reduced temperatures but realistic density ratios between hot gas and coolant. The specimen with the best cooling performance has been selected for an investigation in a high pressure test rig at realistic combustor conditions (pressure, temperature) including fluctuations of the cooling air to simulate combustion instabilities. The cooling performance again is determined by the total cooling effectiveness for a given pressure difference across the combustor liner tiles