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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Geneticky modifikované rostliny ve vztahu k řešení problematiky globálních klimatických změn / Genetically modified plants in relation to solving the issue of global climate changes

Nedělová, Jana January 2014 (has links)
The theoretical part of the diploma thesis summarizes basic facts related to the global climate change and provides up-to-date knowledge on the issue of genetically modified plants more resistant to stress factors of environment, including specific examples of strategies regarding preparation of genetically modified plants resistant particularly to abiotic stress. Although genetically modified plants and global climate changes belong to very important and current issue which public and foremost young generation should be sufficiently aware of, contemporary biology books and high school framework educational program pay to the issue very little attention. Therefore, the goal of this thesis is not only to summarize the basic facts and current knowledge regarding this issue but mainly to handle the issue in didactic level in the form of activating learning tasks. There were 28 learning tasks created in the thesis that gradually in unconventional way familiarize students with the issue of genetically modified plants and with the impacts of climate changes. Students must actively acquire information from accompanying materials to address the tasks properly, think critically over them, utilizing acquired knowledge and experience from the past to some extent. Fourteen tasks were chosen from the file created which...
12

Entwicklung und Evaluation von fehlerspezifischem informativem tutoriellem Feedback (ITF) für die schriftliche Subtraktion

Huth, Katja 07 December 2004 (has links)
Obwohl das Angebot von Feedback in Lehr-Lernsituationen eine wichtige instruktionale Maßnahme darstellt,um Lernende in ihrem Lernprozess zu unterstützen, wird dessen Potenzial in multimedialen Lernumgebungen nur selten optimal genutzt. Feedback, welches in aller Regel im Anschluss an die Bearbeitung von Lernaufgaben bereitgestellt wird und den Lerner über die Qualität seiner Aufgabenbearbeitung informiert, beschränkt sich häufig auf die Bereitstellung einer richtig/falsch Rückmeldung mit einem sich anschließenden, zusätzlichen Lösungsversuch bzw. der Präsentation der richtigen Lösung. Als prototypisch für diese Art der Feedbackgestaltung erweist sich das in mathematischer Grundschulsoftware implementierte Feedback. Der Lerner erhält weder Informationen zu dem Ort und der Art des Fehlers noch einen Hinweis auf die korrekte Lösungsstrategie. Vor diesem Hintergrund bestand ein zentrales Ziel der vorliegenden Arbeit in der Entwicklung von fehlerspezifischem informativem tutoriellem Feedback (ITF) für die schriftliche Subtraktion auf der Grundlage des heuristischen Feedbackmodells von Narciss (2004) und der aus diesem Modell abgeleiteten Gestaltungsprinzipien für ITF. Obwohl allgemein erwartet wird, dass informatives Feedback lernwirksamer ist als Feedback, welches nur die richtige Lösung präsentiert, konnte diese Annahme durch die Ergebnisse der empirischen Feedbackforschung bisher nicht bestätigt werden. So ist die Feedbackforschung durch eine inkonsistente Befundlage gekennzeichnet. Vor diesem empirischen Hintergrund bestand ein weiteres zentrales Ziel der vorliegenden Arbeit in der Überprüfung der Effektivität des entwickelten fehlerspezifischen ITFs hinsichtlich verschiedener Lern- und motivationaler Parameter. Fehlerspezifisches ITF zeichnet sich dadurch aus, dass bei fehlerhaften Aufgabenlösungen Informationen angeboten werden, die auf der Grundlage einer kognitiven Anforderungs- und Fehleranalyse als korrekturrelevant identifiziert worden waren. Diese korrekturrelevanten Informationen werden dem Lernenden ohne Bekanntgabe der korrekten Lösung präsentiert, so dass sich dieser dazu aufgefordert sieht, die bereitgestellten strategischen Informationen in einem erneuten Lösungsversuch unmittelbar anzuwenden. In zwei Studien mit Viertklässlern wurde dieses computergestützte ITF im Hinblick auf seine Lern- und motivationale Wirksamkeit evaluiert. In der ersten Studie (N = 30) erfolgte diese Evaluation gegen eine Feedbackbedingung, welche das üblicherweise in mathematischer Lernsoftware realisierte Knowledge of Response und Knowledge of Correct Response (KR-KCR) Feedback präsentierte. In der zweiten Studie (N = 105) wurden zwei zusätzliche Feedbackbedingungen "Knowledge about Mistake (KR-KM) und Knowledge on How to proceed (KR-KH)" aufgenommen. Diese sind in ihrem Informationsgehalt zwischen dem ITF und dem KR-KCR Feedbackalgorithmus anzusiedeln. Die Ergebnisse beider Studien bestätigen die postulierte Lern- und motivationale Wirksamkeit des fehlerspezifischen ITFs für die schriftliche Subtraktion. Besonders im Vergleich zu der wenig informativen KR-KCR Feedbackbedingung konnten in beiden Studien signifikante Wirksamkeitsunterschiede nachgewiesen werden. Auch im Vergleich zu den komplexeren Feedbackformen Knowledge about mistake (KR-KM) und Knowledge on how to proceed (KR-KH) konnten für die Schüler der ITF Bedingung bessere Leistungen beobachtet werden, auch wenn diese Unterschiede nur partiell signifikant wurden. Die Ergebnisse der vorliegenden Untersuchungen zeigen, dass es möglich ist, auf der Grundlage des von Narciss (2004) vorgestellten Feedbackmodells und der aus diesem Feedbackmodell abgeleiteten Gestaltungsprinzipien lern- und motivationsförderliches ITF zu entwickeln. So liefern die Ergebnisse beider Studien erste empirische Belege für die Annahme, dass informatives Feedback nicht nur den Lernprozess unterstützt, sondern auch motivationsförderlich wirkt. / Feedback is considered to be an important factor to promote learning and motivation with computer-based training tools. However the findings of studies on the effectiveness of feedback are rather inconsistent. One reason for these inconsistent findings might be that the implementation of feedback is more based on intuition than on well-founded design principles. Therefore the aims of the present work was (1) to develop theoretical well-founded elaborated feedback forms for a procedural skill like the written subtraction, (2) to implement them in an adaptive feedback algorithm that induces the mindful processing of feedback, and (3) to evaluate this elaborated feedback regarding his impact on learning and motivation. Using results from prior feedback research and from cognitive task and error analysis of written subtraction tasks, information relevant to the correction of typical systematic errors (e.g. location of error, source of error, type of error and hints to the correct solution strategy) were selected. This information was used to design different types of bug-related feedback messages. These different feedback messages were arranged in an adaptive bug-related algorithm presenting three levels of feedback with increasing informational value to support the learner in finding the correct solution on his own. Because the developed feedback allows assisted multiple response attempts for an item by providing relevant information for error correction, but no immediate Knowledge of Correct Response (KCR) feedback, and by encouraging the learner to apply the corrective information to a further attempt, this kind of feedback was called bug-related "informative tutoring feedback (ITF)". In two computer-based learning experiments cognitive and motivational effects of this bug-related ITF were evaluated with forth-grade students with difficulties in written subtraction. In the first study (N=30) the bug-related ITF was compared to the effects of a standard Knowledge of Result-Knowledge of Correct Response feedback (KR-KCR) algorithm. In the second study (N=105) two additional feedback algorithms - Knowledge about Mistake (KR-KM) und Knowledge on How to proceed (KR-KH) - were implemented. These both feedback algorithms range between the bug-related ITF and the simple KR-KCR feedback regarding to their amount of information. In both studies significant positive effects of the bug-related ITF compared to the KR-KCR feedback could be found. Regarding to the more informative KR-KM and KR-KH feedback a positive effect of the bug-related ITF could be showed sporadic. These results are discussed in detail.
13

The Effects of Emotional Intelligence on Performance of a Cognitive Task in the Context of Collaboration vs. Competition

Fellner, Angela N. January 2008 (has links)
No description available.
14

Busca alimentar, memória espacial e ansiedade em ratos: possível participação do núcleo mamilar medial / Search for food, spatial memory and anxiety in rats: possible participation of the medial mammillary nucleus

Gimenes Júnior, João Antonio 14 July 2008 (has links)
Seres humanos com danos nos corpos mamilares exibem prejuízos no funcionamento da memória episódica. O presente estudo investigou a possível participação do núcleo mamilar medial (MM), estrutura densamente inervada por fibras imunorreativas ao hormônio concentrador de melanina (MCH) potencialmente envolvida no comportamento alimentar, em processos de evocação de memórias sobre locais em que alimento foi previamente encontrado, em ratos. Investigou-se ainda seu envolvimento na memória espacial motivada aversivamente, por meio do labirinto aquático de Morris, e em processos de ansiedade, por meio do labirinto em cruz elevado. Descreve-se uma tarefa comportamental envolvendo busca alimentar orientada por memória espacial em ratos, funcionalmente análoga ao teste de aprendizagem de pares associados, utilizado para avaliar memória episódica em seres humanos. Ratos treinados a escavar numa arena para obter alimento foram expostos ao pareamento de um determinado sabor, e.g., amendoim, com um local da arena e, numa segunda tentativa, ao pareamento de um outro sabor, e.g., avelã, com um local diferente da mesma arena. Antes de uma terceira tentativa, ainda na caixa de espera, os animais receberam uma amostra de amendoim ou avelã. Então, inseridos na arena para uma terceira tentativa, deveriam procurar e escavar por alimento enterrado no local sinalizado pela amostra. As associações sabor-local, a seqüência das associações, os locais do pareamento e a amostra oferecida antes da terceira tentativa, variaram quase aleatoriamente a cada dia. O treinamento dos animais para a aquisição da tarefa foi prolongado. O número de visitas e o tempo de permanência no local da arena sinalizado pela amostra foram significativamente maiores em relação aos parâmetros correspondentes ao local pareado com alimento mas não sinalizado pela amostra, quando o intervalo de tempo entre a 2ª e 3ª tentativas foi 60 ou 120 minutos; Testes de Avaliação sem oferta de alimento na arena na 3ª tentativa, permitiram excluir a hipótese de que os animais desempenharam essa tarefa com base em estímulos olfativos, levando à conclusão que o fizeram com base na memória das associações sabor-local. Ratos com danos seletivos do MM, induzidos pela aplicação tópica, micro-iontoforética, de N-Metil-D-Aspartato (NMDA), testados na tarefa de pares associados sabor-local, não exibiram prejuízo de desempenho em relação aos animais controle. Análises adicionais revelaram que houve uma redução da busca por alimento em ambos os grupos (lesado e controle) nos testes pós-operatórios, em relação ao seu próprio desempenho nos testes pré-operatórios; porém, essa redução foi mais acentuada em relação ao local sinalizado pela amostra, particularmente nos animais do grupo lesado. Estes resultados, embora não conclusivos, podem representar indícios em favor da idéia de que o MM estaria envolvido numa circuitaria relacionada à memória espacial voltada à busca alimentar. Mais estudos seriam necessários para avaliar essa possibilidade. Além disso, esses animais não exibiram qualquer prejuízo no teste de memória de referência espacial no labirinto aquático de Morris e no paradigma do teste e re-teste no labirinto em cruz elevado, sugerindo que esse tipo de lesão não leva a deficiência no funcionamento da memória espacial motivada por estimulação aversiva, na memória aversiva por espaços abertos ou nos mecanismos responsáveis pela ansiedade. / Human beings with damage to the mammillary bodies exhibit episodic memory disruption. This study investigated the potential participation of the medial mammillary nucleus (MM), a structure that receives a high density of melaninconcentrating hormone immunoreactive fibers (MCH) potentially involved in food intake, in processes of retrieval of memory about places where food was previously found, in rats. In addition, we investigated the possible involvement of this brain structure in both aversively motivated spatial memory, using the Morris´ water maze, and in anxiety, using the elevated plus maze. A behavioral task involving search for food guided by spatial memory, in rats, functionally analogous to the paired-associate learning task used for studying episodic memory in humans, was described. Rats trained to dig for food in an arena were exposed both to the pairing of a taste, peanut, with a specific place in the arena and, in a second trial, to the pairing of another taste, hazelnut, with another place in the arena. Immediately before a third trial, while still in the waiting box, the animals received a sample of either peanut or hazelnut. Then, they were inserted into the arena for a third trial and could search and dig for food buried in the place previously associated with the sample. The taste-place associations, sequence of associations, pairing places and sample offered before the third trial, were all varied quasi-randomly every day. The animals took extensive training to learn this task. It was found that the number of visits and the time spent in the place indicated by the sample were significantly greater as compared to the corresponding parameters of the place previously associated with a taste but not indicated by the sample, when the time interval between the second and the third trials was both 60 and 120 min; probe tests with no food in the arena in the third trial allowed to exclude the hypothesis that the rats were performing the task relying on olfactory cues, leading to the conclusion that the animals performed the task relying on the memory for the associations tastefood. Rats with selective damage to the MM, induced by topic, microiontophoretic, injections of N-Methyl-D-Aspartate (NMDA), tested in the taste-place pairedassociate learning task, did not exhibit any disruption of performance relative to the controls. Additional analyses revealed that both MM and control subjects exhibited a reduction of food search during the post-operatory tests as compared to their own performance in pre-operatory tests; however, this reduction was stronger towards the place indicated by the sample, particularly for the animals subjected to MM damage. Even though not conclusive, these results may suggest that the MM might be involved in search for food guided by spatial memory. More studies would be required to evaluate this possibility. Further, these rats did not exhibit any disruption of performance in the reference memory test in the water maze and in the test/re-test elevated plus maze, suggesting that this type of damage does not disrupt aversively motivated spatial memory, open-space aversive memory and anxiety.
15

Busca alimentar, memória espacial e ansiedade em ratos: possível participação do núcleo mamilar medial / Search for food, spatial memory and anxiety in rats: possible participation of the medial mammillary nucleus

João Antonio Gimenes Júnior 14 July 2008 (has links)
Seres humanos com danos nos corpos mamilares exibem prejuízos no funcionamento da memória episódica. O presente estudo investigou a possível participação do núcleo mamilar medial (MM), estrutura densamente inervada por fibras imunorreativas ao hormônio concentrador de melanina (MCH) potencialmente envolvida no comportamento alimentar, em processos de evocação de memórias sobre locais em que alimento foi previamente encontrado, em ratos. Investigou-se ainda seu envolvimento na memória espacial motivada aversivamente, por meio do labirinto aquático de Morris, e em processos de ansiedade, por meio do labirinto em cruz elevado. Descreve-se uma tarefa comportamental envolvendo busca alimentar orientada por memória espacial em ratos, funcionalmente análoga ao teste de aprendizagem de pares associados, utilizado para avaliar memória episódica em seres humanos. Ratos treinados a escavar numa arena para obter alimento foram expostos ao pareamento de um determinado sabor, e.g., amendoim, com um local da arena e, numa segunda tentativa, ao pareamento de um outro sabor, e.g., avelã, com um local diferente da mesma arena. Antes de uma terceira tentativa, ainda na caixa de espera, os animais receberam uma amostra de amendoim ou avelã. Então, inseridos na arena para uma terceira tentativa, deveriam procurar e escavar por alimento enterrado no local sinalizado pela amostra. As associações sabor-local, a seqüência das associações, os locais do pareamento e a amostra oferecida antes da terceira tentativa, variaram quase aleatoriamente a cada dia. O treinamento dos animais para a aquisição da tarefa foi prolongado. O número de visitas e o tempo de permanência no local da arena sinalizado pela amostra foram significativamente maiores em relação aos parâmetros correspondentes ao local pareado com alimento mas não sinalizado pela amostra, quando o intervalo de tempo entre a 2ª e 3ª tentativas foi 60 ou 120 minutos; Testes de Avaliação sem oferta de alimento na arena na 3ª tentativa, permitiram excluir a hipótese de que os animais desempenharam essa tarefa com base em estímulos olfativos, levando à conclusão que o fizeram com base na memória das associações sabor-local. Ratos com danos seletivos do MM, induzidos pela aplicação tópica, micro-iontoforética, de N-Metil-D-Aspartato (NMDA), testados na tarefa de pares associados sabor-local, não exibiram prejuízo de desempenho em relação aos animais controle. Análises adicionais revelaram que houve uma redução da busca por alimento em ambos os grupos (lesado e controle) nos testes pós-operatórios, em relação ao seu próprio desempenho nos testes pré-operatórios; porém, essa redução foi mais acentuada em relação ao local sinalizado pela amostra, particularmente nos animais do grupo lesado. Estes resultados, embora não conclusivos, podem representar indícios em favor da idéia de que o MM estaria envolvido numa circuitaria relacionada à memória espacial voltada à busca alimentar. Mais estudos seriam necessários para avaliar essa possibilidade. Além disso, esses animais não exibiram qualquer prejuízo no teste de memória de referência espacial no labirinto aquático de Morris e no paradigma do teste e re-teste no labirinto em cruz elevado, sugerindo que esse tipo de lesão não leva a deficiência no funcionamento da memória espacial motivada por estimulação aversiva, na memória aversiva por espaços abertos ou nos mecanismos responsáveis pela ansiedade. / Human beings with damage to the mammillary bodies exhibit episodic memory disruption. This study investigated the potential participation of the medial mammillary nucleus (MM), a structure that receives a high density of melaninconcentrating hormone immunoreactive fibers (MCH) potentially involved in food intake, in processes of retrieval of memory about places where food was previously found, in rats. In addition, we investigated the possible involvement of this brain structure in both aversively motivated spatial memory, using the Morris´ water maze, and in anxiety, using the elevated plus maze. A behavioral task involving search for food guided by spatial memory, in rats, functionally analogous to the paired-associate learning task used for studying episodic memory in humans, was described. Rats trained to dig for food in an arena were exposed both to the pairing of a taste, peanut, with a specific place in the arena and, in a second trial, to the pairing of another taste, hazelnut, with another place in the arena. Immediately before a third trial, while still in the waiting box, the animals received a sample of either peanut or hazelnut. Then, they were inserted into the arena for a third trial and could search and dig for food buried in the place previously associated with the sample. The taste-place associations, sequence of associations, pairing places and sample offered before the third trial, were all varied quasi-randomly every day. The animals took extensive training to learn this task. It was found that the number of visits and the time spent in the place indicated by the sample were significantly greater as compared to the corresponding parameters of the place previously associated with a taste but not indicated by the sample, when the time interval between the second and the third trials was both 60 and 120 min; probe tests with no food in the arena in the third trial allowed to exclude the hypothesis that the rats were performing the task relying on olfactory cues, leading to the conclusion that the animals performed the task relying on the memory for the associations tastefood. Rats with selective damage to the MM, induced by topic, microiontophoretic, injections of N-Methyl-D-Aspartate (NMDA), tested in the taste-place pairedassociate learning task, did not exhibit any disruption of performance relative to the controls. Additional analyses revealed that both MM and control subjects exhibited a reduction of food search during the post-operatory tests as compared to their own performance in pre-operatory tests; however, this reduction was stronger towards the place indicated by the sample, particularly for the animals subjected to MM damage. Even though not conclusive, these results may suggest that the MM might be involved in search for food guided by spatial memory. More studies would be required to evaluate this possibility. Further, these rats did not exhibit any disruption of performance in the reference memory test in the water maze and in the test/re-test elevated plus maze, suggesting that this type of damage does not disrupt aversively motivated spatial memory, open-space aversive memory and anxiety.
16

探討空間記憶之神經行為機制 / Investigation of the Neurobehavioral Mechanisms Underlying Spatial Memory

林建佑 Unknown Date (has links)
本研究以神經毒素ibotenic acid破壞不同尾核區域以及鋰鹽去價值程序為操弄變項,觀測此兩種實驗操弄對於大鼠之迷津行為之影響,進而探討標誌系統之行為內涵及神經機制。實驗所採用的作業為線索學習作業以及自我中心作業,分別代表標誌系統下的線索導引策略及體位導向策略。實驗一及實驗二在於檢驗尾核功能缺損對於大鼠迷津行為之影響,從探測嘗試發現大鼠在線索學習的行為表現需依賴砂紙線索的導引,而在自我中心作業之行為則不以環境刺激為依據(實驗一A、二A),顯示大鼠在各迷津作業的行為符合標誌系統的運作原則。神經機制之操弄結果顯示在記憶習得階段,尾核破壞之受試在線索學習作業上的表現並沒有顯著變差,尾核功能缺損並未導致學習的延宕或阻斷,其進步的速度仍與控制組相同(實驗一B)。相較於線索學習作業,尾核破壞之受試在自我中心作業上的表現則明顯變差,幾乎沒有進步的趨勢(實驗二B)。而在記憶保持階段,不管是線索學習作業或自我中心作業之表現皆會因尾核破壞而顯著變差(實驗一C、二C)。實驗三及實驗四則利用鋰鹽去價值程序降低食餌之誘因價值,觀測大鼠行為有無相對應改變。結果發現去價值程序的操弄只會影響到大鼠在自我中心作業的行為表現(實驗四),而不影響其在線索學習作業之行為(實驗三)。由此可知,兩種迷津作業所形成的記憶表徵是不同的,自我中心學習歷程會將增強物表徵在聯結單位中,而線索學習之習得歷程則不會。綜合上述實驗結果,標誌系統下確實有兩個不同空間行為機制,一個為線索導引策略,另一個為體位導向策略,雖皆受到尾核的調節,但調節的程度是不同的。不管是記憶習得或保持階段,尾核在體位導向策略的運作中皆扮演重要的角色,而在線索導引策略只參與了記憶保持歷程的運作。另外,兩個空間行為機制在學習內涵上也不盡相同,以線索導引策略為依據之空間行為會形成刺激反應(S-R)的聯結型態,而以體位導向策略為依據之空間行為則會形成反應及增強物(R-S*)聯結。 / This study investigated the neurobehavioral mechanisms of taxon system of spatial memory through manipulating lesions of subareas in the caudate nucleus by ibotenic acid and lithium chloride (LiCl)-induced reward devaluation. With respect to behavioral measurement in an eight-arm radial maze, a cue learning task and an egocentric task were used for testing the guidance and orientation hypotheses of taxon system, respectively. Data from probing procedures showed that the performance of rats in the cue learning task was impaired when the cue was removed, but the performance in the egocentric task was not affected by changing the context (Experiments 1A and 2A). These results indicate that behavior reactions in two tasks are corresponding to those two operational principles of taxon system. In terms of the acquisition, deficits were significantly produced by the lesion of the dorsomedial caudate on egocentric task, while the ibotenate lesions did not affect cue learning task (Experiments 1B and 2B). For retention test, the performances in both cue learning and egocentric tasks were impaired by dorsomedial caudate lesion, no such impairment was observed from dorsolateral and posterolateral caudate lesions (Experiments 1C and 2C). In the third and fourth experiments, LiCl devaluation procedure was employed to lower the reward value of the bait in the maze. This manipulation significantly impaired the performance of egocentric task but not that of the cue learning task. These results indicate that the memory representations in the two tasks used in the present study are different. The memory representation in the egocentric task contains the reinforcer, whereas that in the cue learning task is not necessarily relevant to the reinforcer. In conclusion, the guidance and orientation hypotheses can be differentiated as behavioral mechanisms existing in the taxon system of spatial memory. Although the caudate nucleus is critically important for the operation of both hypotheses, the degrees of this brain site to get involved are different. The caudate nucleus participates in the acquisition and retention of orientation hypothesis, but only in the retention of guidance hypothesis. In addition, behavioral performance of the spatial memory using guidance hypothesis is based on forming the association of stimulus and response (S-R), while that using orientation hypothesis is based on forming the association of response and reinforcer (R-S*).

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