810 resultados para Health Sciences, Public Health|Psychology, Behavioral Sciences|Education, Health
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Worldwide declines in populations of large elasmobranchs and the potential cascading effects on marine ecosystems have garnered considerable attention. Far less appreciated are the potential ecological impacts of changes in abundances of small to medium bodied elasmobranchs mesopredators. Crucial to elucidating the role of these elasmobranchs is an understanding of their habitat use and foraging ecology in pristine conditions. I investigated the trophic interactions and factors driving spatiotemporal variation in abundances of elasmobranch mesopredators in the relatively pristine ecosystem of Shark Bay, Australia. First, I describe the species composition and seasonal habitat use patterns of elasmobranch mesopredator on the sandflats of Shark Bay. Juvenile batoids dominated this diverse community and were extremely abundant in nearshore microhabitats during the warm season. Stomach content analysis and stable isotopic analysis revealed that there is a large degree of dietary overlap between common batoid species. Crustaceans, which tend to be found in seagrass habitats, dominated diets. Despite isotopic differences between many species, overlap in isotopic niche space was high and there was some degree of individual specialization. I then, investigated the importance of abiotic (temperature and water depth) and biotic (prey and predator abundance) factors in shaping batoid habitat use. Batoids were most abundant and tended to rest in shallow nearshore waters when temperatures were high. This pattern coincides with periods of large shark abundance suggesting batoids were seeking refuge from predators rather than selecting optimal temperatures. Finally, I used acoustic telemetry to examine batoid residency and diel use of the sandflats. Individual batoids were present on the sandflats during both the warm and cold seasons and throughout the diel cycle, suggesting lower sandflat densities during the cold season were a result of habitat shifts rather than migration out of Shark Bay. Combined, habitat use and dietary results suggest that batoids have the potential to seasonally impact sandflat dynamics through their presence, although foraging may be limited on the sandflats. Interestingly, my results suggest that elasmobranch mesopredators in pristine ecosystems probably are not regulated by food supply and their habitat use patterns and perhaps ecosystem impacts may be influenced by their predators.
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Communication signals are shaped by the opposing selection pressures imposed by predators and mates. A dynamic signal might serve as an adaptive compromise between an inconspicuous signal that evades predators and an extravagant signal preferred by females. Such a signal has been described in the gymnotiform electric fish, Brachyhypopomus gauderio, which produces a sexually dimorphic electric organ discharge (EOD). The EOD varies on a circadian rhythm and in response to social cues. This signal plasticity is mediated by the slow action of androgens and rapid action of melanocortins. My dissertation research tested the hypotheses that (1) signal plasticity is related to sociality levels in gymnotiform species, and (2) differences in signal plasticity are regulated by differential sensitivity to androgen and melanocortin hormones. To assess the breadth of dynamic signaling within the order Gymnotiformes, I sampled 13 species from the five gymnotiform families. I recorded EODs to observe spontaneous signal oscillations after which I injected melanocortin hormones, saline control, or presented the fish with a conspecific. I showed that through the co-option of the ancient melanocortin pathway, gymnotiforms dynamically regulate EOD amplitude, spectral frequency, both, or neither. To investigate whether observed EOD plasticities are related to species-specific sociality I tested four species; two territorial, highly aggressive species, Gymnotus carapo and Apteronotus leptorhynchus, a highly gregarious species, Eigenmannia cf. virescens , and an intermediate short-lived species with a fluid social system, Brachyhypopomus gauderio. I examined the relationship between the androgens testosterone and 11-ketotestosterone, the melanocortin α-MSH, and their roles in regulating EOD waveform. I implanted all fish with androgen and blank silicone implants, and injected with α-MSH before and at the peak of implant effect. I found that waveforms of the most territorial and aggressive species were insensitive to hormone treatments; maintaining a static, stereotyped signal that preserves encoding of individual identity. Species with a fluid social system were most responsive to hormone treatments, exhibiting signals that reflect immediate condition and reproductive state. In conclusion, variation in gymnotiform signal plasticity is hormonally regulated and seems to reflect species-specific sociality.
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Adolescence and emerging adulthood are transition points that offer both opportunities and constraints on individual development. The purpose of this study is threefold: First, to examine two models (i.e., young adolescents in grades 7 and 8 and older adolescents in grade 12) of heavy episodic drinking and examine how heavy episodic drinking affects subsequent educational attainment. By utilizing two different developmental transitions, i.e., middle school to high school and high school to college, it may be possible to better understand the temporal effects of alcohol use and subsequent educational attainment. The second purpose of this study is to examine how alcohol use at Time 1 may lead to the problems in the adolescent's immediate context due to alcohol (i.e., problems with parents, peers, romantic relationships, problems at school) and to examine if these problems affect educational attainment over and above alcohol use alone. The third purpose of this study is to examine the potential gender differences in these models. The study uses data from the National Longitudinal Study of Adolescent Health, which is a large scale, nationally representative school based sample of 20,745 adolescents who were interviewed in grades 7 to 12. Two longitudinal mediational models were evaluated utilizing structural equation modeling. Binge drinking and number of days drunk were used as indicators for a latent variable of heavy episodic drinking (i.e., LHED). In the 7th and 8th grade model, direct effects of LHED were found to predict educational attainment at grade 12. Additionally, in the 7th and 8th grade sample, a mediated relationship was found whereby educational attainment was predicted by problems with parents. Problems with parents were predicted by number of days drunk in the past year. In the 12th grade sample, there were no direct effects or indirect effects of alcohol on educational attainment. This study highlights the need for using a longitudinal framework when examining heavy episodic drinking's effects on educational attainment. ^
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The balance between the costs and benefits of conspicuous signals ensures that the expression of those signals is related to the quality of the bearer. Plastic signals could enable males to maximize conspicuous traits to impress mates and competitors, but reduce the expression of those traits to minimize signaling costs, potentially compromising the information conveyed by the signals. ^ I investigated the effect of signal enhancement on the information coded by the biphasic electric signal pulse of the gymnotiform fish Brachyhypopomus gauderio. Increases in population density drive males to enhance the amplitude of their signals. I found that signal amplitude enhancement improves the information about the signaler's size. Furthermore, I found that the elongation of the signal's second phase conveys information about androgen levels in both sexes, gonad size in males and estrogen levels in females. Androgens link the duration of the signal's second phase to other androgen-mediated traits making the signal an honest indicator of reproductive state and aggressive motivation. ^ Signal amplitude enhancement facilitates the assessment of the signaler's resource holding potential, important for male-male interactions, while signal duration provides information about aggressive motivation to same-sex competitors and reproductive state to the opposite sex. Moreover, I found that female signals also change in accordance to the social environment. Females also increase the amplitude of their signal when population density increases and elongate the duration of their signal's second phase when the sex ratio becomes female-biased. Indicating that some degree of sexual selection operates in females. ^ I studied whether male B. gauderio use signal plasticity to reduce the cost of reproductive signaling when energy is limited. Surprisingly, I found that food limitation promotes the investment in reproduction manifested as signal enhancement and elevated androgen levels. The short lifespan and single breeding season of B. gauderio diminishes the advantage of energy savings and gives priority to sustaining reproduction. I conclude that the electric signal of B. gauderio provides reliable information about the signaler, the quality of this information is reinforced rather than degraded with signal enhancement.^
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In order to prepare younger generations to live in a world characterized by interconnectedness, developing global and international perspectives for future teachers has been recommended by the National Council for the Social Studies and the National Council for the Accreditation of Teacher Education. The purpose of this study was to investigate the effects that participation in the International Communication and Negotiation Simulation (ICONS), an Internet-based communication project has on preservice social studies teachers' global knowledge, global mindedness, and global teaching strategies. ^ The study was conducted at a public university in South Florida. A combination of quantitative and qualitative approaches was employed. Two groups of preservice social studies teachers were chosen as participants: a control group composed of 14 preservice teachers who enrolled in a global education class in the summer semester of 1998 and an experimental group that included nine preservice teachers who took the same class in the fall semester of 1998. The summer class was conducted in a traditional format, which included lectures, classroom discussions, and student presentations. The fall class incorporated a five-week Internet-based communication project. The Global Mindedness Scale (Hett, 1993) and an adapted Test of Global Knowledge (ETS, 1981) were administered upon the completion of the class. ^ Contrasting case studies were utilized to investigate the impact of participation in the ICONS on the development of preservice teachers' global pedagogy. Four preservice teachers, two selected from each group were observed and interviewed to explore how they were infusing global perspectives into social studies curriculum and instruction during a 10-week student teaching internship in the spring semester of 1999. ^ This study had three major findings. First, preservice social studies teachers from the experimental group on average scored significantly higher than those from the control group on the global knowledge test. Second, no significant difference was found between the two groups in their mean scores on the Global Mindedness Scale. Third, all four selected preservice social studies teachers were infusing global perspectives into United States and world history curriculum and instruction during their student teaching internship. Using multiple resources was the common pedagogy. The two who participated in the ICONS were more aware of using the communication feature of the Internet and the web sites that reflect more international perspectives to facilitate teaching about the world. ^ Recommendations were made for further research and for preservice studies teacher education program development. ^
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Top predators can have large effects on community and population dynamics but we still know relatively little about their roles in ecosystems and which biotic and abiotic factors potentially affect their behavioral patterns. Understanding the roles played by top predators is a pressing issue because many top predator populations around the world are declining rapidly yet we do not fully understand what the consequences of their potential extirpation could be for ecosystem structure and function. In addition, individual behavioral specialization is commonplace across many taxa, but studies of its prevalence, causes, and consequences in top predator populations are lacking. In this dissertation I investigated the movement, feeding patterns, and drivers and implications of individual specialization in an American alligator (Alligator mississippiensis ) population inhabiting a dynamic subtropical estuary. I found that alligator movement and feeding behaviors in this population were largely regulated by a combination of biotic and abiotic factors that varied seasonally. I also found that the population consisted of individuals that displayed an extremely wide range of movement and feeding behaviors, indicating that individual specialization is potentially an important determinant of the varied roles of alligators in ecosystems. Ultimately, I found that assuming top predator populations consist of individuals that all behave in similar ways in terms of their feeding, movements, and potential roles in ecosystems is likely incorrect. As climate change and ecosystem restoration and conservation activities continue to affect top predator populations worldwide, individuals will likely respond in different and possibly unexpected ways.
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Recent studies have established that yolk hormones of maternal origin have significant effects on the physiology and behavior of offspring in birds. Herrington (2012) demonstrated that an elevation of progesterone in yolk elevates emotional reactivity in bobwhite quail neonates. Chicks that hatched from progesterone treated eggs displayed increased latency in tonic immobility and did not emerge as quickly from a covered location into an open field compared to control groups. For the present study, three experimental groups were formed: chicks hatched from eggs with artificially elevated progesterone (P), chicks hatched from an oil-vehicle control group (V), and chicks hatched from a non-manipulated control group (C). Experiment 1 examined levels of progesterone with High Performance Liquid Chromatography/tandem Mass Spectroscopy (HPLC/MS) from prenatal day 1 to prenatal day 17 in bobwhite quail egg yolk. In Experiment 2, bobwhite quail embryos were passively exposed to an individual maternal assembly call for 24 hours prior to hatching. Chicks were then tested individually for their preference between the familiarized call and a novel call at 24 and 48 hours following hatching. For Experiment 3, newly hatched chicks were exposed to an individual maternal assembly call for 24-hrs. Chicks were then tested for their preference for the familiarized call at 24 and 48-hrs after hatch. Results of Experiment 1 showed that yolk progesterone levels were significantly elevated in treated eggs and were present in the egg yolk longer into prenatal development than the two control groups. Results from Experiment 2 indicated that chicks from the P group failed to demonstrate a preference for the familiar bobwhite maternal assembly call at 24 or 48-hrs after hatch following 24-hrs of prenatal exposure. In contrast, chicks from the C and V groups demonstrated a significant preference for the familiarized call. In Experiment 3, chicks from the P group showed an enhanced preference for the familiarized bobwhite maternal call compared to chicks from the C and V groups at 24 and 48-hrs after hatch. The results of these experiments suggest that elevated maternal yolk hormone levels in pre-incubated bobwhite quail eggs can influence auditory perceptual learning in embryos and neonates.^
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This thesis aims to identify how civil servants perceive changes made inthe carrying out of their work after their taking part in the Course forTechnicians in Public Management of the Government of Rio Grande do NorteState. As for the methodological procedures, an exploratory-descriptivequantitative research has been carried out through structured questionnaires appliedto 118 civil servants from the first groups of the Course for Technicians, thusshowing a margin of error of 4.18% to 95% of confidence, according to theprocedures of finite sampling. The table processing and analysis rested uponthe Statistical Package for the Social Sciences SPSS and was carried outthrough univariate, bivariate and multivariate techniques with emphasis on thetechnique called Factor Analysis. It was possible to identify that the level ofsatisfaction of the students was high and there was a clear perception by themthat the course assisted to changes in their work. Through Factor Analysis itwas verified that the factors that may be related to changes in the work of thecivil servants are "Contribution to Society", "Efficiency andEfficacy in the Work Environment", "Applicability of Contents"and "Capacitating for Leadership". The conclusion of the studyindicates that the factors obtained are directly related to the basis of thenew public management by means of guidance toward efficiency and efficacy in aperspective of leadership, the contents of the course being thus made into newattitudes toward work which end up yielding better results for society
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Objetivo: Associar fatores de risco para doenças crônicas não transmissíveis (DCNT) com variáveis sociodemográficas de servidores de uma instituição pública de ensino superior. Métodos: Estudo transversal, realizado no período de 2012 a 2013. Utilizou-se um questionário com variáveis sociodemográficas, fatores de risco para DCNT e aferição de peso e estatura. Classificou-se o estado nutricional de acordo com o índice de massa corporal. Analisaram-se os dados pelos programas Epi-Info 3.2.1 e Bioestat 5.0. As associações foram verificadas pelos testes qui-quadrado de Yates, de tendência e exato de Fisher (p≤0,05). Resultados: Participaram 225 servidores, maioria de mulheres (64,4%), na faixa etária entre 45-54 anos (37,3%) e escolaridade superior a 12 anos de estudo (85,8%). O sexo associou-se ao excesso de peso (p=0,034), consumo diário de leite integral (p=0,023), consumo insuficiente de frutas, legumes e verduras - FLV (p=0,020) e consumo insuficiente de feijão (p=0,000), sendo mais frequentes entre mulheres. Entre os homens, foi mais frequente o consumo excessivo de bebida alcoólica (p=0,000). O excesso de peso associou-se à faixa etária (p=0,008). O hábito de fumar (p=0,004) e o consumo diário de leite integral (p=0,016) apresentaram associação com a escolaridade. Conclusão: Encontrou-se elevada prevalência de fatores de risco para doenças crônicas não transmissíveis na amostra estudada, com associação para sexo, faixa etária e escolaridade. O excesso de peso apresentou maior ocorrência nas mulheres e nas idades acima de 45 anos, hábitos alimentares inadequados no sexo feminino, maior ingestão de bebida alcoólica no masculino e hábito de fumar nos indivíduos com maior escolaridade.
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International audience
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This thesis aims to identify how civil servants perceive changes made inthe carrying out of their work after their taking part in the Course forTechnicians in Public Management of the Government of Rio Grande do NorteState. As for the methodological procedures, an exploratory-descriptivequantitative research has been carried out through structured questionnaires appliedto 118 civil servants from the first groups of the Course for Technicians, thusshowing a margin of error of 4.18% to 95% of confidence, according to theprocedures of finite sampling. The table processing and analysis rested uponthe Statistical Package for the Social Sciences SPSS and was carried outthrough univariate, bivariate and multivariate techniques with emphasis on thetechnique called Factor Analysis. It was possible to identify that the level ofsatisfaction of the students was high and there was a clear perception by themthat the course assisted to changes in their work. Through Factor Analysis itwas verified that the factors that may be related to changes in the work of thecivil servants are "Contribution to Society", "Efficiency andEfficacy in the Work Environment", "Applicability of Contents"and "Capacitating for Leadership". The conclusion of the studyindicates that the factors obtained are directly related to the basis of thenew public management by means of guidance toward efficiency and efficacy in aperspective of leadership, the contents of the course being thus made into newattitudes toward work which end up yielding better results for society
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Developing nations in Africa are not shielded from the pressures of a globalized competitive agricultural marketplace. With an appreciable bulk of her people deriving livelihoods from diverse agricultural enterprises, these nations must respond to important contemporary issues shaping global agriculture. Farmers from such nations, including Ghana, will be able to improve their participation in the competitive local, regional and global agricultural marketplace if the appropriate agricultural technologies and extension information support are available. To achieve this, a new breed of agricultural extension graduates who can respond to current and emerging challenges in agriculture and interface effectively with farmers must be produced through responsive extension education and training. While extension education can produce effective extensionists to hasten agricultural development, budgetary constraints make it difficult for most African governments to successfully and sustainably implement such educational programs. However, public-private partnership (PPP) initiatives offer a way out of this financial dilemma. Beginning in 1993, the Sasakawa Africa Fund for Extension Education (SAFE) worked with the University of Cape Coast (UCC) in Ghana to develop an innovative extension education program through a public private partnership. The program, comprising a BSc. and Diploma components, was designed to respond to the myriad of challenges facing higher agricultural extension education in Ghana. A key practical feature of the curricula is the “Supervised Enterprise Projects” (SEPS), which enable students to work with relevant stakeholders to identify and tackle agricultural problems in farming communities through experiential extension approaches and action research. The SAFE-UCC initiative fulfils important education goals such as: expanding and improving access; ensuring quality and relevance; ensuring funding and mobilizing resources for sustainability; building partnerships and linkages; and promoting international co-operation. The paper discusses the underlying conditions for a successful public private partnership in agricultural and extension education and sheds light on the impacts, lessons learned and challenges.
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University students are more globally mobile than ever before, increasingly receiving education outside of their home countries. One significant student exchange pattern is between China and the United States; Chinese students are the largest population of international students in the U.S. (Institute of International Education, 2014). Differences between Chinese and American culture in turn influence higher education praxis in both countries, and students are enculturated into the expectations and practices of their home countries. This implies significant changes for students who must navigate cultural differences, academic expectations, and social norms during the process of transition to a system of higher education outside their home country. Despite the trends in students’ global mobility and implications for international students’ transitions, scholarship about international students does not examine students’ experiences with the transition process to a new country and system of higher education. Related models were developed with American organizations and individuals, making it unlikely that they would be culturally transferable to Chinese international students’ transitions. This study used qualitative methods to deepen the understanding of Chinese international students’ transition processes. Grounded theory methods were used to invite the narratives of 18 Chinese international students at a large public American university, analyze the data, and build a theory that reflects Chinese international students’ experiences transitioning to American university life. Findings of the study show that Chinese international students experience a complex process of transition to study in the United States. Students’ pre-departure experiences, including previous exposure to American culture, family expectations, and language preparation, informed their transition. Upon arrival, students navigate resource seeking to fulfill their practical, emotional, social, intellectual, and ideological needs. As students experienced various positive and discouraging events, they developed responses to the pivotal moments. These behaviors formed patterns in which students sought familiarity or challenge subsequent to certain events. The findings and resulting theory provide a framework through which to better understand the experiences of Chinese international students in the context of American higher education.
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En este artículo se presenta el análisis del conjunto de procesos relacionados con la producción simple y ampliada del medio construido. En este sentido, la producción de las condiciones generales de infraestructura, equipamiento y los servicios y el proceso de la producción (vivienda) conforman la unidad básica para la reproducción de la fuerza de trabajo y del capital. La infraestructura, el equipamiento, los espacios públicos, las áreas verdes, los servicios de educación, salud y el aparato socio-cultural cumplen una función fundamental en la creación de las condiciones esenciales para la reproducción de la fuerza de trabajo y la acumulación simple y ampliada del capital.Desde la perspectiva este artículo se centrara en los aspectos relativos a la construcción del espacio y la producción de la vivienda, en una doble dimensión la producción del espacio residencial y la producción de la vivienda.SUMMARYIn this article, it is presented the analysis of the whole of processes related to the simple and extended production of the built environment. To this effect, the production of the general conditions of infrastructure, equipment, services, and the production process of the production units (housing) conform the basic unit for the reproduction of the labour force and capital. The infrastructure, the equipment, the public spaces, the green areas, education services, health, and the socio cultural device, fulfil a fundamental function in the creation of the essential conditions for the reproduction of the labour force and the simple and extended accumulation of capital.From this perspective, this article will focus on the aspects relative to the construction of space and the production of housing, in a double dimension, the production of residential space and the production of housing.
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The increased recognition of the theory in mathematics education is evident in numerous handbooks, journal articles, and other publications. For example, Silver and Herbst (2007) examined ―Theory in Mathematics Education Scholarship‖ in the Second Handbook of Research on Mathematics Teaching and Learning (Lester, 2007) while Cobb (2007) addressed ―Putting Philosophy to Work: Coping with Multiple Theoretical Perspectives‖ in the same handbook. And a central component of both the first and second editions of the Handbook of International Research in Mathematics Education (English, 2002; 2008) was ―advances in theory development.‖ Needless to say, the comprehensive second edition of the Handbook of Educational Psychology (Alexander & Winne, 2006) abounds with analyses of theoretical developments across a variety of disciplines and contexts. Numerous definitions of ―theory‖ appear in the literature (e.g., see Silver & Herbst, in Lester, 2007). It is not our intention to provide a ―one-size-fits-all‖ definition of theory per se as applied to our discipline; rather we consider multiple perspectives on theory and its many roles in improving the teaching and learning of mathematics in varied contexts.