395 resultados para Rust
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Although the alteration of properties resulting from the alloying of metals in their usual commercial forms has been extensively investigated, the field of electrodeposition of alloys is believed generally not to have received the attention that it merits.
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In sport psychology research about emotional contagion in sport teams has been scarce (Reicherts & Horn, 2008). Emotional contagion is a process leading to a specific emotional state in an individual caused by the perception of another individual’s emotional expression (Hatfield, Cacioppo & Rapson, 1994). Apitzsch (2009) described emotional contagion as one reason for collapsing sport teams. The present study examined the occurrence of emotional contagion in dyads during a basketball task and the impact of a socially induced emotional state on performance. An experiment with between-subjects design was conducted. Participants (N=81, ♀=38, M=21.33 years, SD=1.45) were randomly assigned to one of two experimental conditions, by joining a confederate to compose a same gender, ad hoc team. The team was instructed to perform a basketball task as quickly as possible. The between-factor of the experimental design was the confederate’s emotional expression (positive or negative valence). The within-factor was participants’ emotional state, measured pre- and post-experimentally using PANAS (Krohne, Egloff, Kohlmann & Tausch, 1996). The basketball task was video-taped and the number of frames participants needed to complete the task was used to determine the individual performance. The confederate’s emotional expression was appraised in a significantly different manner across both experimental conditions by participants and video raters (MC). Mixed between-within subjects ANOVAs were conducted to examine the impact of the two conditions on participants’ scores on the PANAS subscales across two time periods (pre- and post-experimental). No significant interaction effects but substantial main effects for time were found on both PANAS subscales. Both groups showed an increase in positive and a reduction in negative PANAS scores across these two time periods. Nevertheless, video raters assessment of the emotional states expressed by participants was significantly different between the positive (M=3.23, SD=0.45) and negative condition (M=2.39, SD=0.53; t=7.64, p<.001, eta squared=.43). An independent-samples t-test indicated no difference in performance between conditions. Furthermore, no significant correlation between the extent of positive or negative emotional contagion and the number of frames was observed. The basketball task lead to an improvement of the emotional state of participants, independently of the condition. Even though participants PANAS scores indicated a tendency to emotional contagion, it was not statistically significant. This could be explained by the low task duration of approximately three minutes. Moreover, the performance of participants was unaffected by the experimental condition or the extent of positive or negative emotional contagion. Apitzsch, E. (2009). A case study of a collapsing handball team. In S. Jern & J. Näslund (Eds.), Dynamics within and outside the lab. Proceedings from The 6th Nordic Conference on Group and Social Psychology, May 2008, Lund, pp. 35-52. Hatfield, E., Cacioppo, J. T. & Rapson, R. L. (1994). Emotional contagion. Cambridge: University Press. Krohne, H. W., Egloff, B., Kohlmann, C.-W. & Tausch, A. (1996). Untersuchungen mit einer deutschen Version der „Positive und Negative Affect Schedule“ (PANAS). Diagnostica, 42 (2), 139-156. Reicherts, M. & Horn, A. B. (2008). Emotionen im Sport. In W. Schlicht & B. Strauss (Eds.), Enzyklopädie der Psychologie. Grundlagen der Sportpsychologie (Bd. 1) (S. 563-633). Göttingen: Hogrefe.
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In der Sportpsychologie gibt es bis anhin wenige Studien, welche sich mit dem Phänomen der sozialen Emotionsinduktion befassen (Reicherts & Horn, 2008). Die soziale Emotions-induktion ist ein Prozess, bei welchem der blosse emotionale Ausdruck einer Person ein emotionales Befinden bei einer anderen Person auslöst, welche diesen emotionalen Ausdruck wahrnimmt (McIntosh, Druckman & Zajonc, 1994). Von Apitzsch (2006) wird die soziale Emotionsinduktion in einem theoretischen Artikel als eine mögliche Ursache bezeichnet, warum es zu einem Kollaps von Teams im Sport kommen kann. Die vorliegende Arbeit untersucht die beiden Fragestellungen, ob es beim Lösen einer sportbezogenen Aufgabe unter Teammitgliedern überhaupt zu sozialer Emotionsinduktion kommt und welche Auswirkungen sich daraus für die individuelle Leistung der Teammitglieder ergeben. Zu diesem Zweck wur-den zwei experimentelle Studien mit unterschiedlicher Methodik durchgeführt: Im ersten Experiment mit Between-Subjects Design wurden die Versuchsperson (N = 81, ♀ = 38, M = 21.33 Jahre, SD = 1.45) zufällig einer der beiden experimentellen Bedingungen zugeordnet, wobei sie auf einen Konfidenten trafen, mit welchem sie ein gleichgeschlechtliches Ad Hoc Team bildeten. Als Team mussten sie eine Basketballaufgabe so schnell wie möglich lösen. Der Zwischensubjekt-Faktor des experimentellen Designs was der emotionale Ausdruck des Konfidenten mit positiver oder negativer Valenz und der Innersubjekt-Faktor, das emotionale Befinden der Versuchspersonen, welches prä- und postexperimentell mit der Positive and Negative Affect Schedule erfasst wurde (PANAS: Krohne, Egloff, Kohlmann & Tausch, 1996). Die Zweiergruppe wurde beim Lösen der Basketballaufgabe auf Video aufgenommen und die Anzahl der Frames, welche die Versuchspersonen zur Aufgabenlösung brauchten, wurde als individuelles Leistungsmass verwendet. Im zweiten Experiment wurden dem Konfidenten drei Versuchspersonen (N = 78, ♀ = 33, M = 20.88 Jahre, SD = 1.64) zugeordnet und als Gruppe durchliefen sie beide experimentellen Bedingungen, womit es sich also um ein Within-Subjects Design handelte. Das prä- und postexperimentelle Befinden der Versuchspersonen wurde mit dem Mehrdimensionalen Befindlichkeitsfragebogen erfasst (MDBF: Steyer, Schwenkmezger, Notz & Eid, 1997). Es zeigte sich in beiden Experimenten, dass das emotionale Befinden der Konfidenten von den Versuchspersonen sowie von Videoratern als unterschiedlich zwischen den Bedingungen wahrgenommen wurde (Manipulation-Check). Auch wenn sich eine Tendenz für eine soziale Emotionsinduktion teilweise zeigte, waren die durchgeführten, messwiederholten Varianzanalysen, welche die Auswirkungen der beiden experimentellen Bedingungen auf die Veränderung des emotionalen Befindens der Versuchspersonen prüfen sollten, nicht signifikant. Die durchgeführten t-Tests zeigten überdies, dass sich die Leistung der Versuchspersonen nicht zwischen den beiden experimentellen Bedingungen unterschied. Mit den beiden durchgeführten Experimenten konnten somit die Ergebnisse anderer experimenteller Studien zur sozialen Emotionsinduktion in Gruppen nicht repliziert werden (z.B. Barsade, 2002). Vor diesem Hintergrund wurden abschliessend methodische Änderungen diskutiert, welche eine Verbesserung der Vorgehensweise bei der Erfassung der sozialen Emotionsinduktion in Gruppen beim Lösen einer sportbezogenen Aufgabe zur Folge hätten.
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South African land restitution, by way of which the post-apartheid state compensates victims of racial land dispossession, has been intimately linked to former homelands: prototypical rural claims are those of communities that lost their rights in land when being forcibly relocated to reserves and they now aspire to return to their former lands and homes from their despised ‘homelands’. However, white farmers, who were also dispossessed (although usually compensated) by the apartheid state in the latter’s endeavour to consolidate existing homelands, have lodged restitution claims as well. While the Land Claims Court has principally admitted such restitution claims and ruled upon the merits of individual cases, state bureaucrats, legal activists, as well as other members of the public have categorically questioned and challenged such claims to land rights by whites. Focussing on white land claimaints effected by the establishment of former KwaNdebele, this paper investigates the contested field of moral entitlements emerging from divergent discourses about the true victims and beneficiaries of apartheid. It pays particular attention to land claims pertaining to the western frontier of KwaNdebele – the wider Rust de Winter area, which used to be white farmland expropriated in the mid-1980s for consolidation (that never occurred) and currently vegetates as largely neglected no-man’s-(state-)land under multiple land claims. Being the point of reference for state officials, former white farmers, Ndebele traditionalists, local residents, and other citizens, this homeland frontier is hence analysed as a fateful zone of contestation, in which the terms of a new South African moral community are negotiated.
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von Jirmejahu dem Kleinen [d. i. H. Haug]
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von Conrad Rust
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von Rust
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Applications of foliar fungicides on soybeans have been shown to reduce disease pressure and protect yield under the right conditions, especially in environments that have very wet or humid conditions. In the past decade, fungicide use in Iowa has increased. Initially, growers were concerned with the potential threat of soybean rust, which is controlled effectively by foliar fungicides. In Iowa, however, there has not been any case of yield reduction due to soybean rust. New potential purposes for foliar fungicides include “plant health” benefits and the reduction of foliar diseases endemic in Iowa such as Septoria brown spot, Cercospora leaf blight, and frogeye leaf spot. Currently what is not known is how the efficacy of fungicides is affected when agricultural practices change. Our question: How does plant population affect the efficacy of fungicides?
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En Argentina, al igual que en otros países, las plantaciones de álamo siempre han estado sujetas a peligros fitosanitarios. La roya, causada por Melampsora spp., es una de las enfermedades más serias a nivel mundial. La clasificación de las especies de Melampsora se basa principalmente en las características morfológicas de los estados uredial y telial, y a los hospederos que poseen en su estado aecial y telial. Dada la observación de pústulas con características diferentes a las de Melampsora larici-populina (única especie citada para la provincia de Mendoza), es que el objetivo del presente trabajo fue identificar la especie de Melampsora observada en álamos del clon Stoneville 70, localizados en el distrito de San Carlos, provincia de Mendoza, Argentina. Para ello, fueron tomadas al azar, muestras de hojas sintomáticas, a partir de las cuales se realizó la descripción sintomatológica y posteriormente microscópica, registrándose la morfometría de 100 uredosporas y teliosporas. Las características analizadas concuerdan con aquellas reportadas en la bibliografía para las especies M. larici-tremulae, M. magnusiana, M. pinitorqua y M. rostrupii. Debido a la dificultad que muestran estas especies en ser distinguidas, Wilson y Henderson (1966) adoptan el nombre de M. populnea como especie colectiva. Por ello, se considera oportuno citar a la especie encontrada como M. populnea hasta aclarar con estudios más profundos la identificación definitiva del microorganismo.
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Fil: Duarte Rust, Leandro. Universidade Federal do Mato Grosso (Brasil)
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The aim of this study was to assess genetic diversity among 40 alfalfa (Medicago sativa L.) genotypes of different non-dormant (FD=8) cultivars. Biomass yield, regrowth speed and reaction to spring black stem, lepto leaf spot, and rust were evaluated. Analyses of variances were performed using a mixed model to examine the agronomic variation among individuals. A principal component analysis on standardized agronomic data was performed. Agronomic data were also used to calculate Gower's distance and UPGMA algorithm. For the molecular analysis, six SSR markers were evaluated and 84 alleles were identified. The genetic distance was estimated using standard Nei's distance. Average standard genetic diversity was 0.843, indicating a high degree of variability among genotypes. Finally, a generalized procrustes analysis was performed to calculate the correlation between molecular and agronomic distance, indicating a 65.4% of consensus. This value is likely related to the low number of individuals included in the study, which might have underestimated the real phenotypic variability among genotypes. Despite the low number of individuals and SSR markers analyzed, this study provides a baseline for future diversity studies to identify genetically distant alfalfa individuals or cultivars.
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Investigation of the ferromagnetic fraction of sediments from the Brazil Basin and Rio Grande Rise shows that its main constituents are magnetite and hematite. The magnetite is detrital, but the hematite is both detrital and chemical in origin. Magnetite is the main carrier of the natural remanent magnetization (NRM); therefore, the NRM is detrital remanent magnetization (DRM). In a number of cases, the change of magnetic parameters along the stratigraphic column permits some refinement of the previously defined boundaries of the lithologic units.