Here we present the most detailed morphological study of the auditory region of a tremarctinae bear, Arctotherium tarijense Ameghino. In addition, we provide new anatomical information of the Tremarctinae inner ear, such as coplanarity and deviation from orthogonality of the semicircular canals, as an approach to infer the head movements which encountered the extinct forms in locomotion. Based on morphological comparisons, A. tarijense exhibits the following particular features: the cavum tympani presents the highest relative volume compared with other ursids; the processus paraoccipitalis has a foramen that is absent in other tremarctines; there is only one (ventral) recess in the anterior region of the cavum tympani; and the recessus epytimpanicus is the smallest for all ursids studied. In relation to the inner ear, A. tarijense shows the lowest values of orthogonality deviation and highest scores of locomotor agility. Based on this, is possible to make a preliminary proposal that this species had a relative high vestibular sensibility and therefore a better ability to explore different kind of habitats. However, this hypothesis might be contrasted among bears taking into account the orientation of each semicircular canal in a phylogenetic framework.

In the field of insect circadian rhythms, the honey bee is best known for its foraging time-sense, or Zeitgedächtnis, which permits the forager bee to make precise associations between the presence of food and the time of day. A number of studies, now considered classics, established that bees could be trained to collect food at virtually any time of the circadian cycle and that this timekeeping ability was controlled by an endogenous circadian clock. Recently, behavioral rhythms in bees have been examined using a variety of approaches, in both laboratory and field studies. The following areas of new research are reviewed: (a) the ontogeny of behavioral rhythmicity in newly emerged worker bees; (b) the integration of behavioral rhythmicity with the colony's division of labor; (c) the evidence for social entrainment of behavioral rhythms and for a 'clock of the colony'; (d) the potential linkage between circadian rhythms of general locomotor activity and the foraging time-sense; (e) learning and entrainment hypotheses proposed to explain the mechanism underlying the time-sense; (f) the interplay between extinction and persistence of the time-memory as revealed from the differential behavior of individuals within the foraging group; and (g) comparisons of the Zeitgedächtnis with food-anticipatory rhythms in other animals.

Animal models have previously been used to study tolerance and sensitization using two different procedures that are difficult to compare. Tolerance has been studied by administering a drug to a subject that is engaged in an operant behavior, and sensitization by administering a drug to a subject that is not engaged in an operant behavior. Previous research has shown that sensitization can occur when d-amphetamine is administered to rats emitting an operant behavior for a food presentation. The first goal of the experiment was to show operant sensitization using dose response curves. The second goal of the present experiment was to determine if operant sensitization is context specific. These goals were addressed by administering d-amphetamine to rats engaged in an operant behavior in two stimulus contexts and creating dose-response curves. Sensitization occurred but was not found to be context-specific, with the dose-response curves not being significantly different between the two contexts. It is not clear whether this result was due to the drug administration procedure or the counterbalancing assignments used. Further research is needed to determine whether operant sensitization is context specific.

Analiza la relación entre las funciones neuromusculoesqueléticas y las actividades de vida diaria en usuarios post accidente cerebrovascular del Servicio de Terapia Ocupacional del Instituto Nacional de Ciencias Neurológicas. Se realizó un estudio observacional, de tipo transversal descriptivo y prospectivo. El lugar para la realización de la investigación fue el Instituto Nacional de Ciencias Neurológicas Lima, Perú. Participaron los usuarios del servicio de terapia ocupacional. Se entrevistó a 152 usuarios para analizar como las funciones neuromusculoesqueléticas se relacionan con las actividades de vida diaria, los cuales fueron evaluados con las sub-escalas motoras de miembro superior y miembro inferior de Fugl Meyer y con el Índice de Barthel. Tanto las funciones neuromusculoesqueléticas de miembro superior (P=0.61) como las de miembro inferior (P=0.748) se relacionan positivamente con el desempeño en actividades de vida diaria. Las actividades de alimentación y vestido necesitan puntajes más altos en las funciones de miembro superior; y las actividades de higiene y movilidad funcional necesitan puntajes más altos en las funciones de miembro inferior. En un análisis de regresión donde se incluyeron como variables las características demográficas de la población, se pierde la relación entre las funciones neuromusculoesqueléticas de miembro superior (p=-0.152) y las actividades de vida diaria. Se concluye que las funciones neuromusculoesqueléticas de miembro superior y miembro inferior son igualmente significativas para el desempeño en actividades de vida diaria, sin embargo las características demográficas de la población afectan la relación entre las funciones de miembro superior y el desempeño en actividades de vida diaria. / Tesis

Publicación a texto completo no autorizada por el autor / Determina la influencia de la hiperlaxitud articular sobre el desempeño del equilibrio dinámico en los escolares de 3ro a 6to grado de primaria de la Institución Educativa Privada “El Aposento Alto”, ubicado en el distrito de Independencia, departamento de Lima - Perú, durante el año 2017. Corresponde a un estudio de tipo cuantitativo y descriptivocorrelacional, de diseño no experimental, de corte transversal y prospectivo. Utiliza una muestra de 50 escolares y como instrumento de recolección de datos una ficha de evaluación de elaboración propia, conformada por la escala de Beighton y los ítems sobre equilibrio dinámico de la Batería Psicomotora de Da Fonseca. Encuentra que de los 50 escolares se observó que el 50% presentaron hiperlaxitud articular, siendo esta más frecuente en niñas y a la edad de 11 años. En cuanto al equilibrio dinámico se halla que éste mejora de manera progresiva con la edad y es mejor en las niñas, quienes presentaron mayor equilibrio bueno (30%), seguido del equilibrio regular (20%) y en menor proporción el equilibrio malo (2%); a diferencia de los niños quienes presentaron mayor equilibrio regular (26%), seguido del equilibrio bueno (14%) y en menor proporción el equilibrio malo (8%). Se obtiene que la hiperlaxitud articular no influye significativamente en el equilibrio dinámico de los escolares de primaria evaluados, mostrando un nivel de significancia de p>0,05 para la prueba de Chi-cuadrado. Sin embargo se observó que en el cruce de la variable hiperlaxitud con las actividades del equilibrio dinámico, no se encontró relación entre la hiperlaxitud y las actividades de marcha controlada, evolución en el banco y saltos con apoyo unipodal (p>0,05), solo se encontrándose relación entre la hiperlaxitud y la actividades de saltos con pie juntos (p0,05), sin embargo se encontró relación significativa con el ítem de salto con pies juntos (p<0,05). Concluye que la hiperlaxitud articular no influye significativamente en el desempeño del equilibrio dinámico (p>0,05), sin embargo se encontró relación significativa con el ítem de salto con pies juntos (p<0,05). / Tesis

One of the main objectives of evolutionary biology is to understand the reasons behind the maintenance of individual differences in a multitude of traits that influence fitness such as locomotor performance and behaviour. Because locomotor performance sets an "envelope" within which behaviour is expressed, it is likely that a multitude of co-adaptations exists between these two suites of traits. In recent years, a growing number of studies have identified associations of different strength and directions between performance and behaviour. Two main hypotheses have received support, on one hand locomotor performance could be "co-specialized" with behaviour in a manner that behaviour reduces predation risk, such that shyer, less active, less explorative animals should be the best sprinters and the most endurant. On the other hand, locomotor performance could "compensate" for behaviours that lead to increased predation risk, in a way that bolder, more active and explorative animals should be able to sprint faster and for longer. In my thesis I provide a review of published studies that successfully identify associations between locomotor performance and behaviour and classify each association as supporting the co-specialization or compensation hypothesis respectively. I further elaborate on the importance of using repeated measurements and (co)variance partitioning when studying correlations between labile traits. I also discuss one of the main challenges that comes with studying locomotor performance, namely the importance of the variation in motivation, both methodologically, by using different performance tests, but also physiologically, by using blood corticosterone measurements as indicators of such variation.

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Animals with one of septal, medial thalamic or tegmental reticular formation lesions were compared on three measures of spontaneous activity (a brief test in a novel maze and seven-day tests in running wheels or photocells cages) and on active avoidance learning. Wheel running was depressed by all the lesions (especially septal and tegmental lesions) while locomotion in the maze and photocell cages was unaffected. Avoidance learning was depressed by septal and thalamic lesions but not by tegmental lesions. These results are discussed in terms of the hypothesis that these brain structures form part of systems which facilitate or inhibit somatomotor activity. / Thesis / Master of Arts (MA)