989 resultados para 769
Resumo:
The Sulu Sea is located in the 'warm pool' of the western Pacific Ocean, where mean annual temperatures are the highest of anywhere on Earth. Because this large heat source supplies the atmosphere with a significant portion of its water vapour and latent heat, understanding the climate history of the region is important for reconstructing global palaeoclimate and for predicting future climate change. Changes in the oxygen isotope composition of planktonic foraminifera from Sulu Sea sediments have previously been shown to reflect changes in the planetary ice volume at glacial-interglacial and millenial timeseales, and such records have been obtained for the late Pleistocene epoch and the last deglaciation (Linsley and Thunell, 1990, doi:10.1029/PA005i006p01025; Lindley and Dunbar, 1994, doi:10.1029/93PA03216; Kudrass et al., 1991, doi:10.1038/349406a0). Here I present results that extend the millenial time resolution record back to 150,000 years before present. On timescales of around 10,000 years, the Sulu Sea oxygen-isotope record matches changes in sea level deduced from coral terraces on the Huon peninsula (Chappell and Shackleton, doi:10.1038/324137a0). This is particularly the case during isotope stage 3 (an interglacial period 23,000 to 58,000 years ago) where the Sulu Sea oxygen-isotope record deviates from the SPECMAP deep-ocean oxygen-isotope record (Imbrie et al., 1984). Thus these results support the idea (Chappell and Shackleton, doi:10.1038/324137a0; Shackleton, 1987, doi:10.1016/0277-3791(87)90003-5) that there were higher sea levels and less continental ice during stage 3 than the SPECMAP record implies and that sea level during this interglacial was just 40-50 metres below present levels. The subsequent rate of increase in continental ice volume during the return to full glacial conditions was correspondingly faster than previously thought.
Resumo:
Dans les pays développés, la prévalence des démences est de 5% chez les plus de 65ans et doublerait pour chaque tranche d'âge de 10 ans. Avec le vieillissement de la population, le nombre de personnes atteintes de démence augmente chaque année, ce qui pose le problème de trouver rapidement des thérapies et mesures de prévention efficaces. Il est connu que l'hypertension artérielle (HTA) est un facteur de risque pour certaines démences. De plus, de récentes études démontrent que la pression artérielle centrale serait un marqueur hémodynamique plus représentatif des lésions causées au cerveau, dues à une HTA, que la pression périphérique usuellement mesurée. Il serait donc intéressant d'évaluer si la démence est associée à une augmentation de la pression artérielle centrale, en comparaison avec des patients hypertendus non déments. But de l'étude : Cette étude a pour but de quantifier l'apport de la mesure de la pression artérielle centrale ambulatoire dans la caractérisation des patients avec une démence de type Alzheimer. L'objectif principal est de déterminer la taille de la différence de pression artérielle centrale et son écart-‐type entre les patients hypertendus avec ou sans démence de type Alzheimer afin de pouvoir calculer le nombre de patients nécessaire pour montrer une différence significative. Dans cette étude, nous allons tester l'hypothèse que la pression artérielle centrale (moyenne, systolique et diastolique) est plus élevée chez les patients atteints de troubles cognitifs et/ou qu'ils présentent des perturbations du rythme circadien plus marquées, notamment pour les valeurs durant le sommeil, (non-‐dipping, reverse dipping, extreme dipping).
Resumo:
Este trabalho teve como foco a presença da área de conhecimento música no curso Normal de duas escolas públicas do município de Pelotas/RS: O Instituto Estadual de Educação Assis Brasil e o Colégio Municipal Pelotense. Considerando que esta modalidade formativa habilita professores para o trabalho na educação infantil e anos iniciais do ensino fundamental, investigamos a educação musical que está sendo desenvolvida no curso Normal e em que concepções se apoia esta prática. Após seis anos de vigência da Lei 11.769/2008, que alterou o artigo 26 da Lei de Diretrizes e Bases de 1996 e incluiu a obrigatoriedade do ensino dos conteúdos de música dentro do componente curricular Arte, esta pesquisa compreendeu o processo de adaptação dos currículos escolares, as discussões em torno da atual legislação e as orientações por parte das mantenedoras, tendo em vista a referida Lei. Outra questão presente nesta pesquisa, refere-se à identificação do profissional responsável por trabalhar os conteúdos de música, já que a Lei 11.769/2008 excluiu, por meio de veto presidencial, o artigo que solicitava formação específica na área. Após o período do canto orfeônico no Brasil, as Leis de Diretrizes e Bases de 1961 e 1971, respectivamente, não ratificaram esta área de forma permanente nos currículos escolares. Em 1996, uma nova LDB, suscitaria novas esperanças aos professores de música e aos pesquisadores da área, no entanto, esta legislação não atendeu as expectativas dos profissionais ligados à música, permanecendo a educação musical ausente em muitos contextos educativos. A partir da Lei 11.769/2008, esta pesquisa objetivou identificar se a efetiva inclusão dos conteúdos de música na disciplina de Arte se concretizou, já que a LDB de 1996 não clarificou quais as áreas deveriam ser contempladas dentro deste componente curricular. Além desses aspectos, esta pesquisa também problematizou a atual situação do ensino de música no contexto geral das escolas estaduais e das instituições municipais de Pelotas/RS.
Resumo:
Paropsis atomaria is a recently emerged pest of eucalypt plantations in subtropical Australia. Its broad host range of at least 20 eucalypt species and wide geographical distribution provides it the potential to become a serious forestry pest both within Australia and, if accidentally introduced, overseas. Although populations of P. atomaria are genetically similar throughout its range, population dynamics differ between regions. Here, we determine temperature-dependent developmental requirements using beetles sourced from temperate and subtropical zones by calculating lower temperature thresholds, temperature-induced mortality, and day-degree requirements. We combine these data with field mortality estimates of immature life stages to produce a cohort-based model, ParopSys, using DYMEX™ that accurately predicts the timing, duration, and relative abundance of life stages in the field and number of generations in a spring–autumn (September–May) field season. Voltinism was identified as a seasonally plastic trait dependent upon environmental conditions, with two generations observed and predicted in the Australian Capital Territory, and up to four in Queensland. Lower temperature thresholds for development ranged between 4 and 9 °C, and overall development rates did not differ according to beetle origin. Total immature development time (egg–adult) was approximately 769.2 ± S.E. 127.8 DD above a lower temperature threshold of 6.4 ± S.E. 2.6 °C. ParopSys provides a basic tool enabling forest managers to use the number of generations and seasonal fluctuations in abundance of damaging life stages to estimate the pest risk of P. atomaria prior to plantation establishment, and predict the occurrence and duration of damaging life stages in the field. Additionally, by using local climatic data the pest potential of P. atomaria can be estimated to predict the risk of it establishing if accidentally introduced overseas. Improvements to ParopSys’ capability and complexity can be made as more biological data become available.
Resumo:
This paper presents an analysis of phasor measurement method for tracking the fundamental power frequency to show if it has the performance necessary to cope with the requirements of power system protection and control. In this regard, several computer simulations presenting the conditions of a typical power system signal especially those highly distorted by harmonics, noise and offset, are provided to evaluate the response of the Phasor Measurement (PM) technique. A new method, which can shorten the delay of estimation, has also been proposed for the PM method to work for signals free of even-order harmonics.
Resumo:
This paper reviews the main studies on transit users’ route choice in thecontext of transit assignment. The studies are categorized into three groups: static transit assignment, within-day dynamic transit assignment, and emerging approaches. The motivations and behavioural assumptions of these approaches are re-examined. The first group includes shortest-path heuristics in all-or-nothing assignment, random utility maximization route-choice models in stochastic assignment, and user equilibrium based assignment. The second group covers within-day dynamics in transit users’ route choice, transit network formulations, and dynamic transit assignment. The third group introduces the emerging studies on behavioural complexities, day-to-day dynamics, and real-time dynamics in transit users’ route choice. Future research directions are also discussed.
Resumo:
The impact of urban development and climate change has created the impetus to monitor changes in the environment, particularly, the behaviour, habitat and movement of fauna species. The aim of this chapter is to present the design and development of a sensor network based on smart phones to automatically collect and analyse acoustic and visual data for environmental monitoring purposes. Due to the communication and sophisticated programming facilities offered by smart phones, software tools can be developed to allow data to be collected, partially processed and sent to a remote server over the network for storage and further processing. This sensor network which employs a client-server architecture has been deployed in three applications: monitoring a rare bird species near Brisbane Airport, study of koalas behaviour at St Bees Island, and detection of fruit flies. The users of this system include scientists (e.g. ecologists, ornithologists, computer scientists) and community groups participating in data collection or reporting on the environment (e.g. students, bird watchers). The chapter focuses on the following aspects of our research: issues involved in using smart phones as sensors; the overall framework for data acquisition, data quality control, data management and analysis; current and future applications of the smart phone-based sensor network, and our future research directions.
Resumo:
This article describes investigations into the development of supramolecular systems capable of sensing anions through either displacement type assays or molecular motion. An electron deficient naphthalene diimide thread and electron rich isophthalamide naphthohydroquinone macrocycle was shown to form a coloured pseudorotaxane assembly. Investigations into the ability of such interpenetrated systems to sense anions colorimetrically were undertaken. Anion complexation to the isophthalamide group of the macrocycle causes displacement of the naphthodiimide thread resulting in the loss of colour. The enhanced mechanically bonded binding strength between the naphthodiimide axle and the naphthohydroquinone groups of the macrocycle wheel in the corresponding rotaxane structure however, was found to negate the anion induced displacement process.