893 resultados para trajectory of immigrants
Resumo:
One of the reasons for animals not to grow as fast as they potentially could is that fast growth has been shown to be associated with reduced lifespan. However, we are still lacking a clear description of the reality of growth-dependent modulation of ageing mechanisms in wild animals. Using the particular growth trajectory of small king penguin chicks naturally exhibiting higher-than-normal growth rate to compensate for the winter break, we tested whether oxidative stress and telomere shortening are related to growth trajectories. Plasma antioxidant defences, oxidative damage levels and telomere length were measured at the beginning and at the end of the post-winter growth period in three groups of chicks (small chicks, which either passed away or survived the growth period, and large chicks). Small chicks that died early during the growth period had the highest level of oxidative damage and the shortest telomere lengths prior to death. Here, we show that small chicks that grew faster did it at the detriment of body maintenance mechanisms as shown by (i) higher oxidative damage and (ii) accelerated telomere loss. Our study provides the first evidence for a mechanistic link between growth and ageing rates under natural conditions.
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Over 100 samples of recent surface sediments from the bottomn of the Atlantic Ocean offshore NW Africa between 34° and 6° N have been analysed palynologically. The objective of this study was to reveal the relation between source areas, transport systems, and resulting distribution patterns of pollen and spores in marine sediments off NW Africa, in order to lay a sound foundation for the interpretation of pollen records of marine cores from this area. The clear zonation of the NW-African vegetation (due to the distinct climatic gradient) is helpful in determining main source areas, and the presence of some major wind belts facilitates the registration of the average course of wind trajectories. The present circulation pattern is driven by the intertropical front (ITCZ) which shifts over the continent between c. 22° N (summer position) and c. 4° N (winter position) in the course of the year. Determination of the period of main pollen release and the average atmospheric circulation pattern effective at that time of the years is of prime importance. The distribution patterns in recent marine sediments of pollen of a series of genera and families appear to record climatological/ecological variables, such as the trajectory of the NE trade, January trades, African Easterly Jet (Saharan Air Layer), the northernmost and southernmost position of the intertropical convergence zone, and the extent and latitudinal situation of the NW-African vegetation belt. Pollen analysis of a series of dated deep-sea cores taken between c. 35° and the equator off NW African enable the construction of paleo-distribution maps for time slices of the past, forming a register of paleoclimatological/paleoecological information.
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The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. Data sets in this collection provide methodological and environmental context to all samples collected during the Tara Oceans Expedition (2009-2013).
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The city of Malaga underwent considerable growth in the 19th and 20th centuries. The territorial expansion paired with a massive influx of immigrants occurred in three waves and as a consequence the city of Malaga remains divided into three different parts up to today. The differences between these three neighbourhoods of the city lie in the type of houses, different cultural and industrial activities, socioeconomic level, and very interestingly, also in speech. Thus, the aim of this study is an examination of the interrelation between speech (phonetic features) and urban space in Malaga. A combination of quantitative and qualitative analysis was used, based on two types of data: 1) production data stemming from recordings of 120 speakers; 2) perception data (salience, estimated frequency of use, attitude, spatial and social perception, imitation) which was collected from several surveys with 120 participants each. Results show that the speech production data divides the city of Malaga clearly into three different parts. This tripartition is confirmed by the analysis of the perception data. Moreover, the habitants of these three areas are perceived as different social types, to whom a range of social features is attributed. That is, certain linguistic features, the different neighbourhoods of the city and the social characteristics associated with them are undergoing a process of indexicalization and iconization. As a result, the linguistic features in question function as identity markers on the intraurban level.
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In this paper, we propose a novel control scheme for bilateral teleoperation of n degree-of-freedom (DOF) nonlinear robotic systems with time-varying communication delay. We consider that the human operator contains a constant force on the local manipulator. The local and remote manipulators are coupled using state convergence control scheme. By choosing a Lyapunov-Krasovskii functional, we show that the local-remote teleoperation system is asymptotically stable. It is also shown that, in the case of reliable communication protocols, the proposed scheme guarantees that the remote manipulator tracks the delayed trajectory of the local manipulator. The time delay of communication channel is assumed to be unknown and randomly time varying, but the upper bounds of the delay interval and the derivative of the delay are assumed to be known.
Resumo:
Young people now represent the highest percentage of the world population. Soon, they will be seniors and they will take decisions for a more orderly and equitable world. For this reason, the participation of young people in development planning is very important and many countries are trying to promote it through various measures. This article analyzes the trajectory of youth participation in the Latin American region and specifically the profile of youth participation in Ecuador, country in which the Constitution recognizes the strategic role of youth in development. The case study of Sayausí rural parish in canton Cuenca is analyzed, through surveys, interviews and an Empowerment Evaluation workshop to young people and decentralized government. The results obtained allow to propose strategies to help improve the participation of youth in the community.
Resumo:
A more natural, intuitive, user-friendly, and less intrusive Human–Computer interface for controlling an application by executing hand gestures is presented. For this purpose, a robust vision-based hand-gesture recognition system has been developed, and a new database has been created to test it. The system is divided into three stages: detection, tracking, and recognition. The detection stage searches in every frame of a video sequence potential hand poses using a binary Support Vector Machine classifier and Local Binary Patterns as feature vectors. These detections are employed as input of a tracker to generate a spatio-temporal trajectory of hand poses. Finally, the recognition stage segments a spatio-temporal volume of data using the obtained trajectories, and compute a video descriptor called Volumetric Spatiograms of Local Binary Patterns (VS-LBP), which is delivered to a bank of SVM classifiers to perform the gesture recognition. The VS-LBP is a novel video descriptor that constitutes one of the most important contributions of the paper, which is able to provide much richer spatio-temporal information than other existing approaches in the state of the art with a manageable computational cost. Excellent results have been obtained outperforming other approaches of the state of the art.
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Expulsion from school is life changing. This single event can alter the trajectory of a student's life--for better or for worse. How life changes is unique for each individual student. Risk and protective factors that impact an individual student's resilience determine the level of positive or negative outcomes experienced as a result of expulsion. Educators have the opportunity to take advantage of this disruption in students' education to improve the trajectory of students' lives. However, without thoughtful intervention from caring educators, this interruption in students' education may have an irreparable destructive impact on students' future. The purpose of this study was to understand the expulsion experience from the point of view of the student in order to represent this critical stakeholder group in future policy and program development, implementation, and decision-making. Students' narratives are a means for members of the educational community to access students' experiences and perceptions in order to understand the impact of expulsion on students' lives. Students' perspectives are presented through thick description in this narrative case study. The experience of these eight students is evidence that expulsion can change students' lives in a positive way. Knowing this, responsible educators must develop interventions for expelled students that channel the positive life-changing potential of this experience. Educators must develop interventions focused on bringing forth protective factors that are documented to increase resilience and to make students less susceptible to the risks inherent in removing them from school. Recommendations for educators and policy-makers are presented to assist educators in preventing expulsion and improving educational and socio-emotional outcomes for expelled students.
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It is well known that higher parental socioeconomic status (SES) predicts better child reading outcomes, but little work has been done to unpack this finding. The main overall question addressed by this project was whether cognitive models of the two main reading outcomes, single word reading (SWR) and reading comprehension (RC), performed similarly across levels of parental SES. The current study predicted a differential relation between parental SES and both predictors and outcomes because of the known large relation between parental SES and child oral language development. Three questions examined the mediating effects of cognitive predictors on the relation between parental SES and reading outcomes, the moderating effects of SES on the developmental trajectories of reading outcomes, and the strength of the relationship between SES and the two reading outcomes. Participants were part of two large and comprehensive datasets: the cross-sectional Colorado Learning Disability Research Center (CLDRC; n=1554) sample, and the International Longitudinal Twin Study (ILTS; n=463 twin pairs) sample. In terms of cognitive predictors, the relation between SES and SWR was disproportionately mediated by two language skills, vocabulary (VOC) and phonological awareness (PA). For the RC models, both SWR and oral listening comprehension (OLC) did not disproportionally mediate the relation between RC and SES; however, full mediation was not exhibited. With regard to the trajectory of reading outcomes, SES moderated the starting values of SWR and RC, and the slopes of SWR development. When performance on the control measures of early reading skills (e.g., print knowledge, vocabulary, and decoding skills) was included the models, the moderating effects of SES were completely accounted for by these measures. In terms of outcomes, SES had a stronger relation to RC than to SWR, especially at later ages. These findings have implications for interventions aimed at improving reading outcomes in children from lower SES families.
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Falls are one of the greatest threats to elderly health in their daily living routines and activities. Therefore, it is very important to detect falls of an elderly in a timely and accurate manner, so that immediate response and proper care can be provided, by sending fall alarms to caregivers. Radar is an effective non-intrusive sensing modality which is well suited for this purpose, which can detect human motions in all types of environments, penetrate walls and fabrics, preserve privacy, and is insensitive to lighting conditions. Micro-Doppler features are utilized in radar signal corresponding to human body motions and gait to detect falls using a narrowband pulse-Doppler radar. Human motions cause time-varying Doppler signatures, which are analyzed using time-frequency representations and matching pursuit decomposition (MPD) for feature extraction and fall detection. The extracted features include MPD features and the principal components of the time-frequency signal representations. To analyze the sequential characteristics of typical falls, the extracted features are used for training and testing hidden Markov models (HMM) in different falling scenarios. Experimental results demonstrate that the proposed algorithm and method achieve fast and accurate fall detections. The risk of falls increases sharply when the elderly or patients try to exit beds. Thus, if a bed exit can be detected at an early stage of this motion, the related injuries can be prevented with a high probability. To detect bed exit for fall prevention, the trajectory of head movements is used for recognize such human motion. A head detector is trained using the histogram of oriented gradient (HOG) features of the head and shoulder areas from recorded bed exit images. A data association algorithm is applied on the head detection results to eliminate head detection false alarms. Then the three dimensional (3D) head trajectories are constructed by matching scale-invariant feature transform (SIFT) keypoints in the detected head areas from both the left and right stereo images. The extracted 3D head trajectories are used for training and testing an HMM based classifier for recognizing bed exit activities. The results of the classifier are presented and discussed in the thesis, which demonstrates the effectiveness of the proposed stereo vision based bed exit detection approach.
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We present the results of an analysis of data recorded at the Pierre Auger Observatory in which we search for groups of directionally-aligned events (or 'multiplets') which exhibit a correlation between arrival direction and the inverse of the energy. These signatures are expected from sets of events coming from the same source after having been deflected by intervening coherent magnetic fields. The observation of several events from the same source would open the possibility to accurately reconstruct the position of the source and also measure the integral of the component of the magnetic field orthogonal to the trajectory of the cosmic rays. We describe the largest multiplets found and compute the probability that they appeared by chance from an isotropic distribution. We find no statistically significant evidence for the presence of multiplets arising from magnetic deflections in the present data. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
Esta tese analisa a poesia de Joaquim de Sousa Andrade (1832-1902), ou Sousândrade, e tem por objetivo discutir o imaginário político republicano como elo de ligação entre os poemas O Guesa, especialmente o Canto Décimo (1877), Novo Éden: Poemeto da adolescência, 1888-1889 (1893), Harpa de Ouro (189?) e a continuação O Guesa, o Zac (1902). A cronologia dessas obras indica que é a partir dos anos vividos por Sousândrade nos Estados Unidos que as figurações da República passam a permear os seus escritos. No Canto Décimo, gestado em Nova York, Sousândrade traça um panorama da sociedade estadunidense na década de 1870 e, embora haja críticas à certas práticas econômicas nesse canto, conforme discutiremos com vagar, destaca-se a emulação do poeta em exaltar aquele modelo sociopolítico. Essa atitude do escritor maranhense afinava-se com a visão de brasileiros imigrados nos Estados Unidos naquele mesmo período, os quais formavam uma rede de pensadores liberais comprometidos com a modernização do Brasil. Esse diálogo transatlântico que começa a ser traçado entre Estados Unidos e Brasil caracteriza uma alternativa ao modelo de civilização europeu até então em voga, tema ainda pouco explorado pela historiografia literária. De volta a pátria, Sousândrade dá prosseguimento ao seu fazer poético e, além do seu engajamento na nova conjuntura política do país, dedica-se à construção do mito fundador da República brasileira nos poemas concebidos desde 1893. A trajetória do poeta republicano foi marcada pelo seu anseio de progresso e modernização do Brasil, tarefa na qual ele empenhou-se política e literariamente.
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Civic culture is structured on a network of interpersonal associations with different degrees of formalization. According to theories on civic and political action, certain agents, such as associations, play a key role in setting targets, socializing or coordinating sociopolitical actions, among other functions. Associations strengthen the political and civic system of societies. Likewise, they are a vehicle for individuals’ integration, which is particularly important in the case of immigrants. For these, associations are both a vehicle for integration and an instrument for political participation. This article explores the use and purpose of associations according to immigrants from Romania, Poland, the United Kingdom and Germany living in Spain.
Resumo:
Little, if any, previous research has investigated the involvement of immigrants in sport coaching. This is the first of a series of two articles that focus on this issue. In this article, following a general literature review, structured retrospective interviews (n = 29) are used to construct a profile of immigrant youth sport coaches. Two distinct profiles were identified: (a) leisure-oriented coaches, who had not coached prior to immigration; and (b) career-oriented coaches, who had coached prior to immigration Statistically significant differences (p < .05) were found between groups relating to athletic experience, sport-related education, time between immigration and initiation of coaching, and coaching of their own children Separate pathways to coaching involvement after immigration were identified for both profiles.
Resumo:
The design of South American integration is becoming different. This has been quite common in the trajectory of over six decades of initiatives aimed at generating institutional frameworks to facilitate regional integration. However, even when it has become apparent that the previous design is undergoing a new process of change, it would be difficult to predict for how long the one that is beginning to take shape will remain in effect. The experience of recent decades suggests great caution in forecasts that are optimistic about any eventual longevity. Several factors are contributing to this redesign. Some are external to the region while others are endogenous. The combination of these factors will influence the future design of South American integration. If past lessons are correctly capitalized and certain advantage is derived from the leeway provided by a decentralized international system with multiple options, we can anticipate that what will predominate in the region will be multidimensional integration agreements (with political and economic objectives at the same time) and with cross-memberships and commitments. If this were the case, the actual impact on regional governance, social and productive integration and the competitive insertion at a global scale will depend largely on the following factors: the quality and sustainability of the strategy for development and global and regional insertion of each country; the combination of a reasonable degree of flexibility and predictability in the commitments made and their corresponding ground rule, and the density of the network of cross-interests that can be achieved as a result of the respective regional integration agreements, reflected in multiple transnational social and production networks.