985 resultados para developmental factors


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White matter tractsc onnecting areas involved in speech and motor control were examined using diffusion-tensor imagingingin a sample of peoplewhostutter (n=29) who were heterogeneous with respect to age, sex, handedness and stuttering severity. The goals were to replicate previous findings in developmental stuttering and to extend ourknowledge by evaluating the relationship between white matter differences in people who stutter and factors such as age, sex, handedness and stuttering severity. We replicated previous findings that showed reduced integrity in white matter underlying ventral premotorcortex, cerebral peduncles and posteriorcorpus callosum in people who stutter, relative to controls. Tractography analysis additionally revealed significantly reduced white matter integrity in the arcuate fasciculus bilaterally and the left corticospinal tract and significantly reduced connectivity within theleft corticobulbar tract in people who stutter. Region-of-interest analyses revealed reduced white matter integrity in people whostutter in the three pairs ocerebellar peduncles thatcarry the afferent and efferent fibers of the cerebellum. Within thegroup of people who stutter, the higher the stuttering severity index, the lower the white matter integrity in the leftangular gyrus but the greater the white matter connectivity in theleft corticobulbartract. Also,in people who stutter, handedness and age predicted the integrity of the corticospinal tract and peduncles, respectively. Further studies are needed to determine which of these white matter differences relate to the neural basis of stuttering and which reflect experience-dependent plasticity.

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Oocyte maturation is a long process during which oocytes acquire their intrinsic ability to support the subsequent stages of development in a stepwise manner, ultimately reaching activation of the embryonic genome. This process involves complex and distinct, although linked, events of nuclear and cytoplasmic maturation. Nuclear maturation mainly involves chromosomal segregation, whereas cytoplasmic maturation involves organelle reorganization and storage of mRNAs, proteins and transcription factors that act in the overall maturation process, fertilization and early embryogenesis. Thus, for didactic purposes, we subdivided cytoplasmic maturation into: (1) organelle redistribution, (2) cytoskeleton dynamics, and (3) molecular maturation. Ultrastructural analysis has shown that mitochondria, ribosomes, endoplasmic reticulum, cortical granules and the Golgi complex assume different positions during the transition from the germinal vesicle stage to metaphase II. The cytoskeletal microfilaments and microtubules present in the cytoplasm promote these movements and act on chromosome segregation. Molecular maturation consists of transcription, storage and processing of maternal mRNA, which is stored in a stable, inactive form until translational recruitment. Polyadenylation is the main mechanism that initiates protein translation and consists of the addition of adenosine residues to the 3` terminal portion of mRNA. Cell cycle regulators, proteins, cytoplasmic maturation markers and components of the enzymatic antioxidant system are mainly transcribed during this stage. Thus, the objective of this review is to focus on the cytoplasmic maturation process by analyzing the modifications in this compartment during the acquisition of meiotic competence for development. (c) 2009 Elsevier Inc. All rights reserved.

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This chapter examines the evidence for the effectiveness of interventions aiming to reduce drug-related harm by improving conditions for healthy develeopment in the earliest years through adolescence. Of the interventions beginning prior to birth, there is efficacy evidence that family home visitation is a feasible strategy for implementation with disadvataged families and can reduce risk factors for early developmental deficits and thereby improve childhood development outcomes. There is efficacy evidence for strategies such as parent education and school preparation through the pre-school age period. Some of the strongest evidence for efficacy in reducing developmental pathways to drug-related harm comes from interventions delivered through the early school years to improve educational environments. Of the interventions targeting the high school age period, school drug education has been the most commonly evaluated. The evidence suggests that short term reduction in both drug use and progression to frequent drug use may be achievable through this strategy, but the prospects for longer-term and population-level behaviour change is still unclear. In overview, a range of prevention strategies have been developed and evaluated. Most of the exisiting evidence is restricted to efficacy studies and there are future challenges to progress evaluation through to studies of effectiveness. In general, prevention programmes appear more successful where they maintain intervention activities over a number of years and incorporate more than one strategy. Much of the existing research has been based in North America and evaluates discrete programmes. Future research should test effects in other countries, in different social contexts and seek to better understand the interrelated effects of combining interventions within the community. Developmental prevention programmes target different age periods and social settings, hence communities have the challenge of coordinating a mixture of programmes that address the local conditions that adversely influence child and youth development. There are opportunities in this work to coordinate prevention activities using funding from different jurisdictions (e.g., crime prevention, health promotion, mental health, education, substance abuse prevention).

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The 'Prevention Paradox' applies when low-risk individuals in a population contribute the most cases of a condition or problem behaviour by virtue of their being in the majority, thereby recommending a universal or whole of population approach to prevention. The applicability of a universal as opposed to a targeted high-risk approach to the prevention of youth substance use was examined in two studies of children and adolescents conducted in Victoria, Australia. These studies were reanalysed by recombining developmental, social and individual measures to form cumulative risk indices for substance use. In Study 1, a cross-sectional survey of students, most regular tobacco, alcohol and cannabis use by 15/16-year-olds occurred in the moderate and low-risk groups, recommending a universal prevention strategy . However, the majority of illicit drug use occurred in the highest-risk group (top 15%). Furthermore, in younger age groups both legal and illegal drug use was concentrated mainly in the highest risk group. Study 2 used data from a major longitudinal study where risk factors at around age 11/12 years were used to predict substance use at age 17/18 years. Most students who admitted involvement in frequent smoking, heavy drinking and, although to a lesser degree, cannabis were classified as low or average risk. It is concluded that universal prevention strategies are needed for late adolescent alcohol, tobacco and cannabis use and more targeted strategies for addressing harm related to early age drug use, frequent cannabis use and illegal drug use. [Stockwell T, Toumbouru JW, Letcher P, Sanson A, Bond L. Risk and protection factors for different intensities of adolescent substance use: when does the prevention paradox apply?

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South Korea is often cited as a case of miraculous transformation from poverty to prosperity. Korea’s achievement of moving from one of the world’s poorest countries as recently as the early 1960s to the ranks of the ten biggest economies only four decades later has rightly attracted interest from policymakers and scholars alike.

This book identifies the factors that shaped relations between the state and big business in Korea, the ‘developmental alliance’. These factors offer a cogent framework in which to identify and predict changes in power relations between government and business. Rather than merely offering a means of explaining the rapid-growth phase of Korean development, the politics of the developmental alliance also help us understand how and why the Korean miracle turned to crisis in 1997 and why the subsequent recovery has been so uneven. In this way, the book highlights the political power of business, which is often underplayed in discussions of the development of Korea. It also sheds light on the constraints on policymakers during modernisation, and how power is shared among a small number of powerful parties.

Illustrating the tumultuous politics of the ‘developmental alliance’ between business and government during the rise and decline of South Korea’s economic miracle, this book is an essential read for anyone interested in Korean politcs, economics and development,

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This paper evaluates the legacy of the developmental state, which has been by most measures a successful vehicle of socioeconomic transformation. It seeks to clarify the features of the Asian model of development, to assess its contemporary significance, and to highlight the distinctive strands of national capitalism in the region. Consequently, the paper clarifies the factors which contributed to the formation of developmental states, and also the function of such states. Geopolitical, socioeconomic and political change since the Asian financial crisis of 1997–98 has undermined the assumptions of the developmental state thesis. In seeking to ascertain the elements of the developmental state model which are most impervious to change, the paper finds comparatively greater variation in terms of state–business interaction with society than in the will and capacity of states to adopt a developmental orientation.

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Songbirds sing complex songs as a result of evolution through sexual selection. The evolution of such sexually selected traits requires genetic control, as well as selection on their expression. Song is controlled by a discrete neural pathway in the brain, and song complexity has been shown to correlate with the volume of specific song control nuclei. As such, the development of these nuclei, in particular the high vocal centre (HVC), is thought to be the mechanism controlling signal expression indicating male quality. We tested the hypothesis that early developmental stress selectively affects adult HVC size, compared with other brain nuclei. We did this by raising cross–fostered zebra finches (Taeniopygia guttata) under stressed and controlled conditions and determining the effect on adult HVC size. Our results confirm the strong influence of environmental conditions, particularly on HVC development, and therefore on the expression of complex songs. The results also show that both environmental and genetic factors affect the development of several brain nuclei, highlighting the developmental plasticity of the songbird brain. In all, these results explain how the complex song repertoires of songbirds can evolve as honest indicators of male quality.

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Maternally derived yolk antibodies provide neonates with immune protection in early life at negligible cost to mothers. However, developmental effects on the neonate's future immunity are potentially costly and thus could limit yolk antibody deposition. The benefits to neonatal immunity must be balanced against costs, which may depend on neonate vulnerability to pathogens, developmental trajectories and the immunological strategies best suited to a species' pace of life. We measured yolk antibodies and life-history features of 23 species of small Neotropical birds and assessed the evidence for each of several hypotheses for life history and ecological effects on the evolution of yolk antibody levels. Developmental period and yolk antibodies are negatively related, which possibly reflect the importance of humoral immune priming through antigen exposure, and selection to avoid autoimmunity, in species with a slower pace of life. There is also a strong relationship between body size and yolk antibody concentration, suggesting that larger species are architecturally equipped to produce and transfer higher concentrations of antibodies. These results suggest that developmental effects of maternally derived antibodies, such as imprinting effects on B-cell diversity or autoimmune effects, are important and deserve more consideration in future research.

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The research found significant relationships between secondary exposure to client trauma and symptoms associated with secondary traumatic stress and vicarious trauma in a sample of community mental health clinicians. The research supports developmental conceptualisations of the relationships between these constructs and burnout, and identifies potential individual vulnerability and protective factors. The portfolio explores the impact of childhood maltreatment from an attachment theory perspective. Four clinical cases are presented illustrating the clinical relevance of the impact of childhood maltreatment and attachment disturbance, and the complexities associated with current attachment classification systems and differential diagnosis.

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The role of criminological theory should be to inform practice. Program developers should start with a recognized theory about the causes of crime and then design interventions that target factors identified in that theory. Unfortunately, the link between theory and practice is not always apparent. In this paper, a number of prominent developmental theories of crime are considered. These theories are significant in that they provide a strong basis for understanding young offending, and how both the criminal justice system and service providers should approach the task of working constructively with those who appear before the court. This is followed by a review of programs that have been designed to address the risk factors identified in these developmental theories.

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Background: Dental caries (decay) is the most prevalent disease of childhood. It is often left untreated and can impact negatively on general health, and physical, developmental, social and learning outcomes. Similar to other health issues, the greatest burden of dental caries is seen in those of low socio-economic position. In addition, a number of diet-related risk factors for dental caries are shared risk factors for the development of childhood obesity. These include high and frequent consumption of refined carbohydrates (predominately sugars), and soft drinks and other sweetened beverages, and low intake of (fluoridated) water. The prevalence of childhood obesity is also at a concerning level in most countries and there is an opportunity to determine interventions for addressing both of these largely preventable conditions through sustainable and equitable solutions. This study aims to prospectively examine the impact of drink choices on child obesity risk and oral health status.
Methods/Design: This is a two-stage study using a mixed methods research approach. The first stage involves qualitative interviews of a sub-sample of recruited parents to develop an understanding of the processes involved in drink choice, and inform the development of the Discrete Choice Experiment analysis and the measurement instruments to be used in the second stage. The second stage involves the establishment of a prospective birth cohort of 500 children from disadvantaged communities in rural and regional Victoria, Australia (with and without water fluoridation). This longitudinal design allows measurement of changes in the child’s diet over time, exposure to fluoride sources including water, dental caries progression, and the risk of childhood obesity.
Discussion: This research will provide a unique contribution to integrated health, education and social policy and program directions, by providing clearer policy relevant evidence on strategies to counter social and environmental factors which predispose infants and children to poor health, wellbeing and social outcomes; and evidence-based strategies to promote health and prevent disease through the adoption of healthier lifestyles and diet. Further, given the absence of evidence on the processes and effectiveness of contemporary policy implementation, such as community water fluoridation in rural and regional communities it’s approach and findings will be extremely
informative.

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Institutionally collected data identifying student demographics, course performance in both the precollege mathematics course and the college-level mathematics course, and 'stopping-out' time between the pre-college course and the college-level course were used to create a predictive model of academic success for 'high risk' college-level mathematics students. The two most significant factors were the pre-college mathematics course grade and the student's over-all college GPA.

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1. In the past 30 years the prevalence of obesity and overweight have doubled. It is now estimated that globally over 500 million adults are obese and a further billion adults are overweight. Obesity is a cardiovascular risk factor and some studies suggest that up to 70% of cases of essential hypertension may be attributable, in part, to obesity. Increasingly, evidence supports a view that obesity-related hypertension may be driven by altered hypothalamic signalling, which results in inappropriately high appetite and sympathetic nerve activity to the kidney.

2. In addition to the adult risk factors for obesity and hypertension, the environment encountered in early life may ‘programme’ the development of obesity, hypertension and cardiovascular disease. In particular, maternal obesity or high dietary fat intake in pregnancy may induce changes in fetal growth trajectories and predispose individuals to develop obesity and related sequelae.

3. The mechanisms underlying the programming of obesity-related hypertension are becoming better understood. However, several issues require clarification, particularly with regard to the role of the placenta in transferring fatty acid to the fetal compartment, the impact of placental inflammation and cytokine production in obesity.

4. By understanding which factors are most associated with the development of obesity and hypertension in the offspring, we can focus therapeutic and behavioural interventions to most efficiently reduce the intergenerational propagation of the obesity cycle.

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Cigarette smoking is increased in people with trait anxiety and anxiety disorders, however no longitudinal data exist illuminating whether smoking in adolescence can influence the developmental trajectory of anxiety symptoms from early vulnerability in infancy to adult anxiety expression. Using The Tracing Opportunities and Problems in Childhood and Adolescence (TOPP) Study, a community-based cohort of children and adolescents from Norway who were observed from the age of 18months to age 18–19years, we explored the relationship between adolescent smoking, early vulnerability for anxiety in infancy (e.g. shyness, internalizing behaviors, emotional temperaments) and reported early adult anxiety.

Structural equation modeling demonstrated that adolescent active smoking was positively associated with increased early adulthood anxiety (β = 0.17, p<0.05), after controlling for maternal education (proxy for socioeconomic status). Adolescent anxiety did not predict early adult smoking. Adolescent active smoking was a significant effect modifier in the relationship between some infant vulnerability factors and later anxiety; smoking during adolescence moderated the relationship between infant internalizing behaviors (total sample: active smokers: β = 0.85,p<0.01, non-active smokers: ns) and highly emotional temperament (total sample: active smokers: β = 0.55,p<0.01,non-active smokers: ns), but not shyness, and anxiety in early adulthood. The results support a model where smoking acts as an exogenous risk factor in the development of anxiety, and smoking may alter the developmental trajectory of anxiety from infant vulnerability to early adult anxiety symptom expression. Although alternative non-mutually exclusive models may explain these findings, the results suggest that adolescent smoking may be a risk factor for adult anxiety, potentially by influencing anxiety developmental trajectories. Given the known adverse health effects of cigarette smoking and significant health burden imposed by anxiety disorders, this study supports the importance of smoking prevention and cessation programs targeting children and adolescence.