On the seasonal onset of polar mesospheric clouds and the breakdown of the stratospheric polar vortex in the Southern Hemisphere

Southern Hemisphere (SH) polar mesospheric clouds (PMCs), also known as noctilucent clouds, have been observed to be more variable and, in general, dimmer than their Northern Hemisphere (NH) counterparts. The precise cause of these hemispheric differences is not well understood. This paper focuses on one aspect of the hemispheric differences: the timing of the PMC season onset. Observations from the Aeronomy of Ice in the Mesosphere satellite indicate that in recent years the date on which the PMC season begins varies much more in the SH than in the NH. Using the Canadian Middle Atmosphere Model, we show that the generation of sufficiently low temperatures necessary for cloud formation in the SH summer polar mesosphere is perturbed by year‐to‐year variations in the timing of the late‐spring breakdown of the SH stratospheric polar vortex. These stratospheric variations, which persist until the end of December, influence the propagation of gravity waves up to the mesosphere. This adds a stratospheric control to the temperatures in the polar mesopause region during early summer, which causes the onset of PMCs to vary from one year to another. This effect is much stronger in the SH than in the NH because the breakdown of the polar vortex occurs much later in the SH, closer in time to the PMC season

Variations in dynamic knee valgus and gluteus medius onset timing in non-athletic females related to hormonal changes during the menstrual cycle.

It has been suggested that activities of daily living could contribute to the occurrence of ACL injury in females. Currently, no studies have focused on the lower extremity behavior of a non-athletic population to compare or understand the lower extremity adeptness towards daily movements that mimic athletic tasks. Our hypothesis was that increased knee valgus angles would occur during the late follicular phase of the menstrual cycle accompanied by different onset timing of the gluteus medius muscle. In a controlled laboratory study, 23 non-athletic collegiate females participated and 15 subjects comprised the final sample for statistical analysis. Subjects performed a single leg drop landing maneuver while 3-D knee kinematics and gluteus medius muscle onset timing were assessed throughout three distinct phases of the menstrual cycle, confirmed by blood hormone analysis. In general, knee valgus angles were significantly less in the luteal phase compared to both follicular phases (p\u3c0.005), while differences were not observed for gluteus medius onset timing (p=0.936). As a decreased knee joint valgus angle was observed during the luteal phase, it was hypothesized that the hormone progesterone could significantly influence knee kinematics during a dynamic task. However, such influence was not observed for gluteus medius EMG onset timing as a significant correlation between gluteus medius onset timing and knee valgus angle could not be determined

Tipo de conhecimento sobre inclusão produzido pelas pesquisas Type of knowledge about inclusion produced by research

As pesquisas brasileiras sobre produção de conhecimento no campo da Educação Especial iniciaram-se há mais de 15 anos. No presente objetivou-se analisar o tipo de conhecimento produzido nessa área frente à metodologia empregada nas dissertações e teses financiadas pelo Programa de Apoio a Educação Especial. Os trabalhos de conclusão de curso analisados referiam-se àqueles projetos aprovados pelo Proesp no âmbito do Estado de São Paulo. O período de análise ficou compreendido entre 2004 e 2008. Vinte e sete estudos foram localizados. A análise dos estudos foi realizada por meio de cinco categorias: 1) pesquisas que apresentaram generalização e aplicação imediata dos resultados; 2) pesquisas que apresentaram resultados imediatos para um grupo específico de participantes; 3) pesquisas descritivas com achados inovadores; 4) pesquisas de intervenção com achados inovadores; 5) pesquisas descritivas que corroboraram outras pesquisas. Foi possível concluir que os estudos avançaram nos conhecimentos sobre a inclusão e que o uso de metodologias pouco utilizadas no campo da educação serviu de subsídio para obter os resultados.<br>The Brazilian research on knowledge production in the field of Special Education began more than 15 years ago. The objective was to analyze the type of knowledge produced in the area before the methodology used in dissertations funded by the "Programa de Apoio a Educação Especial - PROESP". The final paper analyzed referred to those projects approved by PROESP within the State of São Paulo. The analysis period was between 2004 and 2008. Twenty-seven studies were found. The review was conducted through five categories: 1) studies that showed generalization and immediate application of the results, 2) research that showed immediate results for a specific group of participants, 3) descriptive research with innovative findings, 4) intervention research with innovative findings and 5) descriptive research that corroborated other studies. It was concluded that the studies advance in knowledge on inclusion and the use of some infrequent methodologies in education served as a subsidy to get the results