858 research outputs found

    Effects of roads on wildlife in an intensively modified landscape

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    This paper examines the ecological impacts arising from road networks and the potential ameliorating effects of roadside habitat in a highly modified landscape. A U.K. focus has been adopted to illustrate the effects of roads in a landscape with a long history of land use and intensive land management where the impacts and the potential for improvement are considerable. The impacts of roads in the ecological landscape include habitat loss, fragmentation, and degradation. These interrupt and modify natural processes altering community structures and in the longer term, population dynamics. The large number of fauna fatalities each year from road traffic accidents is also of concern. Road verges can however also provide habitat opportunities and restore connectivity in an otherwise fragmented landscape offering potential to offset some of the adverse impacts of the existing road network. This review demonstrates that roads can present both ecological costs and ecological benefits although currently there is insufficient evidence to confirm some of the key theories which relate to the impact of the barrier effects (at population level) or the value of road verges as ecological corridors. In the absence of complete information the full extent of the problems and opportunities cannot be gauged and every effort should be made therefore to enhance the habitat adjacent to existing roads and to constrain further fragmentation caused by the development of the existing road network. Where further construction is unavoidable conditions should be enforced to prevent roads from reducing further the remaining habitats of conservation value and the connectivity between such habitats

    Does More Money Make You Fat? The Effects of Quasi-Experimental Income Transfers on Adolescent and Young Adult Obesity

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    This paper examines how exogenous income transfers during adolescence affect contemporaneous body mass index (BMI) measures and young adult obesity rates using evidence from the Great Smoky Mountains Study of Youth. The effects of extra income differ depending on the households’ initial socio-economic status, tracing out an inverted U-shaped relationship between initial income and BMI. Youths who resided in families that had high pre-treatment annual incomes experience no change in young adult obesity rates as a result of the income transfers, while the BMI of poorer children increases. Part of this effect is due to differential increases in height, as well as weight. An exogenous annual transfer of $4,000 per adult family member results in an almost 4 cm gain in height-for-age. Adolescents coming from worse-off households experience an increase in weight only, without the corresponding change in height. The cumulative effects of the increase in household income persist for several years into young adulthood.obesity, health, cash transfer, adolescents, indigenous peoples

    Parents’ Incomes and Children’s Outcomes: A Quasi-Experiment

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    Identifying the effect of parental incomes on child outcomes is difficult due to the correlation of unobserved ability, education levels and income. Previous research has relied on the use of instrumental variables to identify the effect of a change in household income on the young adult outcomes of the household’s children. In this research, we examine the role that an exogenous increase in household incomes due to a government transfer unrelated to household characteristics plays in the long run outcomes for children in affected households. We find that children who are in households affected by the cash transfer program have higher levels of education in their young adulthood and a lower incidence of criminality for minor offenses. These effects differ by initial household poverty status as is expected. Second, we explore two possible mechanisms through which this exogenous increase in household income affects the long run outcomes of children – parental time (quantity) and parental quality. Parental quality and child interactions show a marked improvement while changes in parental time with child does not appear to matter.quasi-experiment, criminality, cash transfer programs, difference-in-differences, educational attainment, panel data

    Does more money make you fat? The effects of quasi-experimental income transfers on adolescent and young adult obesity

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    This paper examines how exogenous income transfers during adolescence affect contemporaneous body mass index (BMI) measures and young adult obesity rates using evidence from the Great Smoky Mountains Study of Youth. The effects of extra income differ depending on the households' initial socio-economic status, tracing out an inverted U-shaped relationship between initial income and BMI. Youths who resided in families that had high pre-treatment annual incomes experience no change in young adult obesity rates as a result of the income transfers, while the BMI of poorer children increases. Part of this effect is due to differential increases in height, as well as weight. An exogenous annual transfer of $4,000 per adult family member results in an almost 4 cm gain in height-for-age. Adolescents coming from worse-off households experience an increase in weight only, without the corresponding change in height. The cumulative effects of the increase in household income persist for several years into young adulthood

    Parents' incomes and children's outcomes: a quasi-experiment

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    Identifying the effect of parental incomes on child outcomes is difficult due to the correlation of unobserved ability, education levels and income. Previous research has relied on the use of instrumental variables to identify the effect of a change in household income on the young adult outcomes of the household´s children. In this research, we examine the role that an exogenous increase in household incomes due to a government transfer unrelated to household characteristics plays in the long run outcomes for children in affected households. We find that children who are in households affected by the cash transfer program have higher levels of education in their young adulthood and a lower incidence of criminality for minor offenses. These effects differ by initial household poverty status as is expected. Second, we explore two possible mechanisms through which this exogenous increase in household income affects the long run outcomes of children - parental time (quantity) and parental quality. Parental quality and child interactions show a marked improvement while changes in parental time with child does not appear to matter

    Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation

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    The Integrated Science Investigation of the Sun (ISIS) is a complete science investigation on the Solar Probe Plus (SPP) mission, which flies to within nine solar radii of the Sun's surface. ISIS comprises a two-instrument suite to measure energetic particles over a very broad energy range, as well as coordinated management, science operations, data processing, and scientific analysis. Together, ISIS observations allow us to explore the mechanisms of energetic particles dynamics, including their: (1) Origins-defining the seed populations and physical conditions necessary for energetic particle acceleration; (2) Acceleration-determining the roles of shocks, reconnection, waves, and turbulence in accelerating energetic particles; and (3) Transport-revealing how energetic particles propagate from the corona out into the heliosphere. The two ISIS Energetic Particle Instruments measure lower (EPI-Lo) and higher (EPI-Hi) energy particles. EPI-Lo measures ions and ion composition from approx. 20 keV/nucleon-15 MeV total energy and electrons from approx.25-1000 keV. EPI-Hi measures ions from approx. 1-200 MeV/nucleon and electrons from approx. 0.5-6 MeV. EPI-Lo comprises 80 tiny apertures with fields-of-view (FOVs) that sample over nearly a complete hemisphere, while EPI-Hi combines three telescopes that together provide five large-FOV apertures. ISIS observes continuously inside of 0.25 AU with a high data collection rate and burst data (EPI-Lo) coordinated with the rest of the SPP payload; outside of 0.25 AU, ISIS runs in low-rate science mode whenever feasible to capture as complete a record as possible of the solar energetic particle environment and provide calibration and continuity for measurements closer in to the Sun. The ISIS Science Operations Center plans and executes commanding, receives and analyzes all ISIS data, and coordinates science observations and analyses with the rest of the SPP science investigations. Together, ISIS' unique observations on SPP will enable the discovery, untangling, and understanding of the important physical processes that govern energetic particles in the innermost regions of our heliosphere, for the first time. This paper summarizes the ISIS investigation at the time of the SPP mission Preliminary Design Review in January 2014

    Which executive functioning deficits are associated with AD/HD, ODD/CD and comorbid AD/HD+ODD/CD?

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    Item does not contain fulltextThis study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).17 p

    A longitudinal twin study of the association between childhood autistic traits and psychotic experiences in adolescence

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    - Background: This twin study investigated whether autistic traits during childhood were associated with adolescent psychotic experiences. - Methods: Data were collected from a community sample of approximately 5000 twin pairs, which included 32 individuals with diagnosed autism spectrum conditions (ASC). Parents rated autistic traits in the twins at four points between ages 8–16 years. Positive, negative, and cognitive psychotic experiences were assessed at age 16 years using self- and parent-report scales. Longitudinal twin analyses tested the associations between these measures. - Results: Autistic traits correlated weakly or nonsignificantly with positive psychotic experiences (paranoia, hallucinations, and grandiosity), and modestly with cognitive psychotic experiences (cognitive disorganisation). Higher correlations were observed for parent-rated negative symptoms and self-reported anhedonia, although the proportion of variance in both accounted for by autistic traits was low (10 and 31 %, respectively). The majority of the genetic influences on negative symptoms and anhedonia were independent of autistic traits. Additionally, individuals with ASC displayed significantly more negative symptoms, anhedonia, and cognitive disorganisation than controls. - Conclusions: Autistic traits do not appear to be strongly associated with psychotic experiences in adolescence; associations were also largely restricted to negative symptoms. Of note, the degree to which the genetic and environmental causes of autistic traits influenced psychotic experiences was limited. These findings thus support a phenotypic and etiological distinction between autistic traits and psychotic experiences

    Longitudinal Patterns of Anxiety From Childhood to Adulthood: The Great Smoky Mountains Study

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    The aims of this study were twofold: 1) to provide a brief introduction to the prospective, longitudinal Great Smoky Mountains Study and review recent findings; and 2) to use this sample to conduct an epidemiologic analysis of common childhood anxiety disorders

    Adult Diagnostic and Functional Outcomes of DSM-5 Disruptive Mood Dysregulation Disorder

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    Disruptive mood dysregulation disorder is a new disorder for DSM-5 that is uncommon and frequently co-occurs with other psychiatric disorders. Here, we test whether meeting diagnostic criteria for this disorder in childhood predicts adult diagnostic and functional outcomes
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