Untersuchungen zum Einsatz alternativer Stoffe zur Regulierung des Apfelschorfes

Falllaubzerstörende Maßnahmen im Sinne einer offensiven Bekämpfung des Apfelschorfes, Venturia inaequalis, führen zu einer Abtötung oder Schwächung pilzlicher Strukturen, die im Frühjahr für die epidemiologisch entscheidenden primären Infektionen verantwortlich sind. Die Projektidee war, durch die Verwendung mikrobiologischer Nährmedien und von Enzymen die natürlichen Mikroben zu fördern und einen zusätzlichen enzymatischen Blattabbau zu erreichen. Bei der Blattzersetzung und insbesondere beim Ascosporenpotential waren durch die applizierten Medien deutliche Effekte zu verzeichnen, wobei eine Korrelation zwischen Zersetzungsrad und vermindertem Ascosporenpotential die Ausnahme war. 19 Medien bewirkten eine überwiegend deutliche Reduktion des Ascosporenpotentials mit einer Verringerung von bis zu 93 %. Die zellwandabbauenden Enzyme hatten alleine eine deutliche und zusammen mit einigen Medien eine verbesserte Wirkung. Eine direkte Förderung der Askosporenausschleuderung war geringfügig durch einen Extrakt aus Saponaria officinalis und durch einen Rhamnus frangula-Rindenextrakt zu erzielen, während eine schwache Hemmung durch Citrus-Extrakt und eine starke Hemmung durch Kupfer, zuckerartige Stoffe und spezifische Inhibitoren vorlag. In Gewächshausversuchen zur direkten Schorfbekämpfung zeigten Extrakte aus Inula viscosa, Quillaja saponaria-Rinde, Citrus-species und S. officinalis eine deutliche Wirkung. ELOT-VIS, CHITOPLANT, COMCAT, LEBERMOOSER, SILIOPLANT und FZB 24 hatten bei den gewählten Zeitabständen zur Infektion keine ausreichende Wirkung. Kombinationen aus Quillaja-Saponin und Netzschwefel reduzierten den Schorfbefall sehr stark. In einem Versuch zur Regenstabilität wiesen der Citrus-Extrakt und das Quillaja-Saponin bereits bei einer simulierten Regenmenge von 5 mm Schwächen in der Wirkung auf. Kombinationen von Citrus-extrakt mit GREEMAX und BIOPLUSS als Haftmittel waren in ihrer Wirkung vergleichbar mit einer Mittelmenge Kupferoxychlorid entsprechend 400 g Reinkupfer je ha

Entscheidungsverhalten bei Patienten mit Morbus Parkinson

Vergangene Studien haben das Entscheidungsverhalten von Parkinson Patienten entweder mit dem Iowa Gambling Task (IGT) oder mit dem Game of Dice Task (GDT) untersucht. Um Entscheidungen optimal treffen zu können sind je nach vorliegender Situation emotionale und/oder kognitive Prozesse notwendig. Das Ziel dieser Studie ist eine Untersuchung des emotionalen (IGT) und des kognitiven Entscheidungsverhaltens (GDT) sowie möglicher Einflussfaktoren und Zusammenhängen mit Beeinträchtigungen des täglichen Lebens. 23 Parkinson Patienten und 21 gesunde Personen haben dasselbe neuropsychologische Assessment durchlaufen. Zusätzlich zum IGT und GDT wurden beide Gruppen mit dem Simple Reversal Paradigm (SRLP; Reversal Learning) und dem Wisconsin Card Sorting Test (WCST; Exekutive Funktionen) getestet um Einflussfaktoren auf das Entscheidungsverhalten zu untersuchen. Außerdem wurden Fragebögen eingesetzt um Depression und Beeinträchtigungen im täglichen Leben feststellen zu können. Parkinson-Patienten schnitten im Vergleich zu den Kontrollgruppenpersonen beim GDT signifikant schlechter ab, beim IGT, beim Reversal Learning und bei den exekutiven Funktionen gab es keine signifikanten Unterschiede. Auffällig war jedoch eine signifikante positive Korrelation von riskantem Entscheidungsverhalten und der Anzahl von Perseverationsfehlern. Es gab außerdem eine signifikante Korrelation zwischen den Beeinträchtigungen im täglichen Leben und dem emotionalen Entscheidungsverhalten. Die vorliegenden Daten zeigen, dass Parkinson Patienten in frühem bis mittleren Erkrankungsstadium ein Defizit im kognitiven Entscheidungsverhalten aufweisen, welches in riskanten Situationen von Bedeutung ist. Dieses Ergebnis wird durch eine Korrelation mit den exekutiven Funktionen gestützt und lässt eine Beeinträchtigung der dorsolateren Schleife vermuten, welche eine Verbindung der Basalganglien zum dorsolateralen präfrontalen Kortex darstellRecent studies have examined decision-making ability of patients suffering from Parkinson´s disease (PD) using either the Iowa Gambling Task (IGT) or the Game of Dice Task (GDT). The purpose of this study was to examine the performance of patients with PD on the IGT and the GDT, possible influences on these measures and impairements of activities of daily living. 23 patients with PD as well as 21 control subjects performed the same neuropsychological test battery. In addition to the IGT (uses implicit rules; emotional decision making) and the GDT (uses explicit rules; cognitive decision making) both groups were assessed with the Simple Reversal Paradigm (SRLP; reversal learning) and the Wisconsin Card Sorting Test (WCST; executive functions) to evaluate underlying mechanisms of the decision making process. Neuropsychological assessment included also questionnaires evaluating depression and impairments of activities of daily living. While patients with PD performed poorly on the GDT relative to normal controls, there was no significant difference between the two groups on IGT performance. There were no differences between PD patients and normal controls on the SRLP and the WCST. The impairments on the GDT contributed to a higher number of perseverative errors on the WCST. Furthermore there was a significant positive correlation between impairments of activities of daily living and IGT scores. These data suggest that patients with PD in early and middle stages are impaired in cognitive decision making which is attributed to risky situations. There is also an influence of executive functions to this deficit. The impairment can therefore be attributable to a dysfunctional dorsolateral loop which connects the basal ganglia and the dorsolateral prefrontal cortex

Guiding pre-service teachers' visual attention through instructional settings: an eye-tracking study

In complex classroom situations, pre-service teachers often struggle to identify relevant information. Consequently, classroom videos are widely used to support pre-service teachers’ professional vision. However, pre-service teachers need instructional guidance to attend to relevant information in classroom videos. Previous studies identified a specific task instruction and prompts as promising instructions to enhance pre-service teachers’ professional vision. This mixed-methods eye-tracking study aimed to compare pre-service teachers’ visual attention to information relevant for classroom management in one of three instructional conditions. Participants viewed two classroom videos and clicked a button whenever they identified situations relevant to classroom management in the videos. They got either (1) a specific task instruction before video viewing (n = 45), (2) attention-guiding prompts during video viewing (n = 45), or (3) a general task instruction (n = 45) before video viewing as a control group. We expected a specific task instruction and prompts to better guide participants’ visual attention compared to a general task instruction before video viewing because both experimental conditions contained informational cues to focus on specific dimensions of classroom management. As both a specific task and prompts were assumed to activate cognitive schemata, resulting in knowledge-based processing of visual information, we expected the specific task instruction to have a similar attention-guiding effect as prompts during video viewing. Measurements were conducted on an outcome level (mouse clicks) and on a process level (eye tracking). Findings confirmed our hypotheses on an outcome level and in part on a process level regarding participants’ gaze relational index. Nevertheless, in a disruptive classroom situation, participants of the prompting condition showed better attentional performance than participants of the other conditions regarding a higher number of fixation and a shorter time to first fixation on disruptive students. Further qualitative analyses revealed that, when observing classroom videos without instructional guidance, pre-service teachers were less likely to identify disruptive situations in the video and more likely to attend to other situations of classroom management concerning the teachers’ action. We discuss advantages of both attention-guiding instructions for pre-service teacher education in terms of the economy of implementation and the salience of situations

Étale motivic cohomology and algebraic cycles

We consider etale motivic or Lichtenbaum cohomology and its relation to algebraic cycles. We give an geometric interpretation of Lichtenbaum cohomology and use it to show that the usual integral cycle maps extend to maps on integral Lichtenbaum cohomology. We also show that Lichtenbaum cohomology, in contrast to the usual motivic cohomology, compares well with integral cohomology theories. For example, we formulate integral etale versions of the Hodge and the Tate conjecture, and show that these are equivalent to the usual rational conjectures

Specifying computer-supported collaboration scripts

Collaboration scripts are activity programs which aim to foster collaborative learning by structuring interaction between learners. Computer-supported collaboration scripts generally suffer from the problem of being restrained to a specific learning platform and learning context. A standardization of collaboration scripts first requires a specification of collaboration scripts that integrates multiple perspectives from computer science, education and psychology. So far, only few and limited attempts at such specifications have been made. This paper aims to consolidate and expand these approaches in light of recent findings and to propose a generic framework for the specification of collaboration scripts. The framework enables a description of collaboration scripts using a small number of components (participants, activities, roles, resources and groups) and mechanisms (task distribution, group formation and sequencing)

Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients.

AIM To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between 125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives