533 research outputs found

    Auf der Suche nach Deutschsprachigen:Sprechbereitschaft und -fähigkeit im DaF-Unterricht durch Projektunterricht fördern

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    Dieser Beitrag widmet sich der Frage, wie italienische DaF-Studierende, die im Sprechen oft gehemmt sind, dazu gebracht werden können, ihre mündliche Kompetenz zu verbessern. Die LernerInnen haben aufgrund ihrer Lernsozialisation oft Schwierigkeiten, sich auf Deutsch auszudrücken. Hauptgrund dafür sind bei den meisten die selbstdiagnostizierten sprachlichen Unzulänglichkeiten. Obgleich oft falsch, führt diese Selbsteinschätzung zu Angst vorm Sprechen und mindert die Motivation, sich mündlich am Unterricht zu beteiligen. Daher sollten Lernende im Rahmen von Projekten Kontakt zu Deutschsprachigen bekommen und ‚kommunikative Ernstfälle‘ erleben. Nachdem die Lernenden in solchen Situationen positive Erfahrungen gesammelt haben, verändert sich in der Regel ihre Einschätzung der eigenen mündlichen Kompetenzen, was sich wiederum positiv auf die Motivation auswirkt

    Predation on Eggs of Aedes aegypti (Diptera: Culicidae): Temporal Dynamics and Identification of Potential Predators During the Winter Season in a Temperate Region

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    In temperate regions, the populations of Aedes aegypti (L.) remain in the egg stage during the cold season. The ability of these eggs to survive until the next favorable season is affected by several mortality factors, including the action of predators. In the present study, we analyzed the temporal dynamics of the loss of eggs and identified predators of Ae. aegypti eggs along the unfavorable season in a temperate region of Argentina. To this end, eggs were exposed in field conditions in pitfall traps, where walking arthropod taxa were captured during 1-wk periods from early June to early September (Austral winter).The association of arthropod taxa with the loss of eggs was analyzed to identify potential predators. Based on the results obtained, two taxa were chosen to confirm their capacity to consume eggs in a laboratory study. The proportion of lost eggs and the abundance of predators were significantly higher in the winter–spring transition, although results were heterogeneous among traps in all exposure periods. Ants of the genus Strumigenys, isopods of the species Armadillidium vulgare (Isopoda: Armadilloidea), and dermapterans of the species Euborellia annulipes (Dermaptera: Anisolabidae) were positively associated with a high proportion of lost eggs. In laboratory conditions, A. vulgare and E. annulipes consumed the offered eggs, thus confirming their predator capacity.This study represents the first record of predation of Ae. aegypti eggs in temperate South America and the first evidence of dermapterans consuming mosquito eggs.Fil: Byttebier, Bárbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Fischer, Sylvia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

    Seasonal and environmental variables related to the abundance of immature mosquitoes in rain pools of a peri-urban park of Buenos Aires (Argentina)

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    The aim of the present study was to investigate the variables associated with the composition of mosquito species in rain pools of ‘Bosque de Ezeiza’, a large peri-urban forested park of Buenos Aires city, Argentina. A total of 12 rain pools were sampled biweekly over a 1-yr period in search of mosquito immature stages. Mosquito immature stages were present in all the occasions in which water bodies were recorded. A total of 14 species of five genera were identified, with the highest abundances observed in autumn and spring. The total abundance varied among dates according to previous temperature, precipitation, and flooding conditions. Only one species, Psorophora cyanescens (Coquillett) (Diptera: Culicidae), was associated with extreme conditions (high temperature and prolonged period of drought). Besides drought periods, two main variables were related to species composition: temperature, which accounted for seasonal changes in species composition, and flooding history, which accounted for the predominance of floodwater mosquito species on recently flooded dates and for that of stagnant water species on dates with a longer permanence of water. Regarding the pools, the most important variables accounting for species composition were the insolation level and the variability in the flooded area, with floodwater mosquitoes associated with pools with high variability in the flooded area. Interestingly, Culex (Mel.) pilosus (Dyar and Knab) (Diptera: Culicidae) showed temporal and spatial dynamics more similar to floodwater species than to stagnant water species in the rain pools studied.Fil: Urcola, Juan Ignacio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Fischer, Sylvia Cristina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

    Predadores de mosquitos

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    Fil: Fischer, Sylvia. Grupo de Estudio de Mosquitos. Instituto de Ecología, Genética y Evolución de Buenos Aires. Departamento de Ecología, Genética y Evolución. Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. CABA; ArgentinaFil: Byttebier, Barbara. Grupo de Estudio de Mosquitos. Instituto de Ecología, Genética y Evolución de Buenos Aires. Departamento de Ecología, Genética y Evolución. Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. CABA; ArgentinaFil: Campos, Raúl Ernesto. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

    Predation ability and non-consumptive effects of Notonecta sellata (Heteroptera: Notonectidae) on immature stages of Culex pipiens (Diptera: Culicidae)

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    Predators may have multiple effects on prey, including the mortality caused by consumption, but also non-consumptive effects when prey alter their life history traits in the presence of predators. This study aimed to describe the consumption ability and the non-consumptive effects of Notonecta sellata (Heteroptera: Notonectidae) on immature stages of Culex pipiens (Diptera: Culicidae). Results showed that adult N. sellata were capable of preying on all larval instars, although they consumed more individuals of the 2nd and 3rd instars. Immature mosquitoes raised in the presence of, but without contact with, predators showed a slower development and smaller-sized emerging adults than those raised in the control treatments. Similar survival rates were recorded in the predator and control treatments. The present study suggests that N. sellata adults negatively affect Cx. pipiens populations in two ways: a) by increasing immature stage mortality as a result of direct consumption and extended development times; and b) by reducing their number of offspring, as a result of delayed reproduction and a lower fecundity of adults.Facultad de Ciencias Naturales y Muse

    Predation ability and non-consumptive effects of Notonecta sellata (Heteroptera: Notonectidae) on immature stages of Culex pipiens (Diptera: Culicidae)

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    Predators may have multiple effects on prey, including the mortality caused by consumption, but also non-consumptive effects when prey alter their life history traits in the presence of predators. This study aimed to describe the consumption ability and the non-consumptive effects of Notonecta sellata (Heteroptera: Notonectidae) on immature stages of Culex pipiens (Diptera: Culicidae). Results showed that adult N. sellata were capable of preying on all larval instars, although they consumed more individuals of the 2nd and 3rd instars. Immature mosquitoes raised in the presence of, but without contact with, predators showed a slower development and smaller-sized emerging adults than those raised in the control treatments. Similar survival rates were recorded in the predator and control treatments. The present study suggests that N. sellata adults negatively affect Cx. pipiens populations in two ways: a) by increasing immature stage mortality as a result of direct consumption and extended development times; and b) by reducing their number of offspring, as a result of delayed reproduction and a lower fecundity of adults.Facultad de Ciencias Naturales y Muse

    Sprechfähigkeit und -willigkeit fördern: Das Dilemma der Grammatikvermittlung

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    Analyse des neuen Proteins TMEM59 und seiner Funktion in dem Transport und der Prozessierung des Amyloid-Vorläufer-Proteins

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    Das Golgi-lokalisierte Protein TMEM59 stellt zusammen mit seinem Homolog BSMAP eine neue Proteingruppe von Modulatoren dar, welche die Golgi-Glykosylierungs-Prozesse beeinflussen können. Vorliegende Arbeit identifiziert das Protein TMEM59 als einen starken Inhibitor der APP-Glykosylierung und der APP-Prozessierung

    Trabajando contenidos de ecología a partir de modelos en un contexto significativo : La invasión de ardillas en Buenos Aires

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    Se presenta un trabajo práctico inédito desarrollado en la materia Ecología General, una de las materias del ciclo troncal de la Licenciatura en Ciencias Biológicas que se dicta en la Facultad de Ciencias Exactas y Naturales de la UBA. Distintas experiencias innovadoras de los últimos años en los trabajos prácticos de la carrera tuvieron como objetivo un mayor protagonismo de los alumnos, tal como se plantea desde distintos marcos teóricos. La planificación tuvo como objetivos aplicar los modelos de crecimiento poblacional clásicos y la integración de los mismos con las invasiones biológicas. La actividad se basó en un artículo científico que propone un modelo para predecir el comportamiento de la invasión de la ardilla de vientre rojo a partir de la liberación de ejemplares en Jáuregui, Buenos Aires. El proceso de transposición didáctica incluyó la simplificación del tratamiento matemático del modelo. Se propuso a los alumnos estimar a partir de ciertos parámetros conocidos y un mapa simplificado del área, cual sería el tamaño poblacional y el área de distribución de la especie invasora luego de 30 años. Repensar los modelos de crecimiento poblacional generando un contexto significativo fue valorado por los alumnos y permitió además acercarlos al uso de modelo

    Hatching Response of Aedes aegypti (Diptera: Culicidae) Eggs at Low Temperatures: Effects of Hatching Media and Storage Conditions

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    In temperate regions, Aedes aegypti (L.) (Diptera: Culicidae) populations remain in the egg stage during the cold season. To ensure the start of a new breeding season, eggs should hatch at the beginning of a favorable period. The aim of the current study was to investigate the hatching response of two Ae. aegypti egg batches collected and stored for 3 mo under different conditions, to different low immersion temperatures. Two different hatching media (water and yeast solution) were used for the first batch and only one (water) for the second egg batch. Eggs were immersed for 8 d, during which the number of hatched eggs was recorded daily. The proportion of hatched eggs, delay of the hatching response, proportion of dead larvae, and proportion of remaining eggs within the first egg batch were compared between the two hatching media at each temperature. These parameters also were compared between the two batches immersed in water. Hatching rates were higher and faster in the yeast solution. The hatching response was lower at lower immersion temperatures and among eggs stored under field conditions at colder temperatures (second batch). Among the eggs stored in the laboratory (first batch), older eggs exhibited lower hatching response. The proportion of dead larvae was higher in the yeast solution and in the eggs stored in the laboratory. The conditions that triggered a lower hatching response led to higher proportions of remaining eggs, allowing the population to maintain an egg bank for future favorable opportunities.Fil: Byttebier, Bárbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: de Majo, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Fischer, Sylvia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin
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