18 research outputs found

    Summer range fidelity of radio-collared caribou in Alaska's Central Arctic Herd

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    Sixty-four adult (2 + years) female caribou (Rangifer tarandus grand), radio-collared in April or May 1975 - 82, were relocated during the following June and/or July within the summer range of the Central Arctic Herd (CAH). Relocations made during the following three summers were used to assess range fidelity. Cumulative relocations of radio-collared females in the Central Arctic region were equivalent to 91% of the projected availability based on transmitter life. A chronological analysis indicates that 98%, 91%, and 82% of radio-collared females were found there one, two, and three years later; most of the progressively lower relocation success is probably attributable to transitter malfunctions rather than emigration. These observations suggest that summer range fidelity of adult females in the CAH is at least 90%, and may approach 100%

    Abundance and movements of caribou in the oilfield complex near Prudhoe Bay, Alaska

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    We examined the distribution and movements of 141 radiocollared female caribou (Rangifer tarandus granti) of the Central Arctic Herd during summer, 1980-1993. Numbers of caribou locations within each of 5 quadrats along the arctic coast were totalled separately for days during which insects were active and inactive, and numbers of east-west and west-east crossings of each quadrat mid-line were determined from sequential observations. Both abundance and lateral movements of radiocollared females in the quadrat encompassing the intensively-developed Prudhoe Bay oilfield complex were significantly lower than in other quadrats (P < 0.001 and P < 0.00001, respectively). Avoidance of, and fewer movements within, the complex by female caribou are ostensibly in response to the dense network of production and support facilities, roads, above-ground pipelines, and the associated vehicular and human activity. Impaired access to this area constitutes a functional loss of habitat

    Applications of electrified dust and dust devil electrodynamics to Martian atmospheric electricity

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    Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kVm-1 to 100 kVm-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)-MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ measurements

    Summer range fidelity of radio-collared caribou in Alaska's Central Arctic Herd

    Get PDF
    Sixty-four adult (2 + years) female caribou (Rangifer tarandus grand), radio-collared in April or May 1975 - 82, were relocated during the following June and/or July within the summer range of the Central Arctic Herd (CAH). Relocations made during the following three summers were used to assess range fidelity. Cumulative relocations of radio-collared females in the Central Arctic region were equivalent to 91% of the projected availability based on transmitter life. A chronological analysis indicates that 98%, 91%, and 82% of radio-collared females were found there one, two, and three years later; most of the progressively lower relocation success is probably attributable to transitter malfunctions rather than emigration. These observations suggest that summer range fidelity of adult females in the CAH is at least 90%, and may approach 100%

    Abundance and movements of caribou in the oilfield complex near Prudhoe Bay, Alaska

    Get PDF
    We examined the distribution and movements of 141 radiocollared female caribou (Rangifer tarandus granti) of the Central Arctic Herd during summer, 1980-1993. Numbers of caribou locations within each of 5 quadrats along the arctic coast were totalled separately for days during which insects were active and inactive, and numbers of east-west and west-east crossings of each quadrat mid-line were determined from sequential observations. Both abundance and lateral movements of radiocollared females in the quadrat encompassing the intensively-developed Prudhoe Bay oilfield complex were significantly lower than in other quadrats (P < 0.001 and P < 0.00001, respectively). Avoidance of, and fewer movements within, the complex by female caribou are ostensibly in response to the dense network of production and support facilities, roads, above-ground pipelines, and the associated vehicular and human activity. Impaired access to this area constitutes a functional loss of habitat

    Relationships between parental mental illness and/or offending and offspring contact with the police in childhood: Findings from a longitudinal record-linkage study

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    BACKGROUND: Parental offending and mental illness are associated with an increased risk of criminal behaviour in offspring during adolescence and adulthood, but the impact of such problems on younger children, including children's experiences of victimisation, is less well known. AIM: To investigate the associations between parental offending and mental illness recorded prior to their offspring's age of 5 years and their offspring's contact with police as a 'person of interest', 'victim' or 'witness' between ages 5 and 13 years. METHODS: Our sample consisted of 72,771 children and their parents drawn from the New South Wales Child Development Study, an Australian longitudinal population-based record linkage study. Logistic regression analyses were conducted to examine associations between parental factors and offspring's police contact. Separate models examined the relationships between maternal or paternal offending and mental illness, as well as the combination among either or both parents, as the independent variables, and their child's police contact as the dependent variable. RESULTS: Parental offending and mental illness were each individually associated with indices of police contact among offspring. Stronger associations were observed when both offending and mental illness were present together (in either parent, or when one parent had both exposures). Stronger associations were evident for mothers with both factors across all offspring police contact types, relative to fathers with both factors, in fully adjusted models; that is, children of mothers with both factors were over four times as likely to have contact with police as a 'person of interest' (OR = 4.29; 95% CI = 3.75-4.92) and over three times as likely to have contact as a victim (OR = 3.35; 95% CI = 3.01-3.74) or witness (OR = 3.58; 95% CI = 3.03-4.24), than children whose mothers had no history of offending or mental illness. CONCLUSIONS: Children with a parental history of offending and mental illness in early life are at an increased likelihood of early police contact as young as 5-13 years of age; it is vital that this is taken as a signal to help them and their affected families according to need.Ulrika Athanassiou, Melissa J. Green, Stacy Tzoumakis, Tyson Whitten, Kristin R. Laurens, Felicity Harris, Vaughan J. Carr, Kimberlie Dea

    Transitions between socio-emotional and cognitive vulnerability profiles from early to middle childhood: a population study using multi-agency administrative records

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    Published online: 4 February 2020Adult psychosocial difficulties, including psychiatric disorders, are often preceded by childhood psychosocial vulnerabilities, presenting critical windows of opportunity for preventative intervention. The present study aimed to identify longitudinal patterns (representing transitions between profiles) of childhood socio-emotional and cognitive vulnerability in the general population from early to middle childhood, in relation to key risk factors (e.g. parental mental illness and offending). Data were drawn from the New South Wales Child Development Study, which combines intergenerational multi-agency administrative records with cross-sectional assessments using data linkage methods. We analysed data from childhood assessments of socio-emotional and cognitive functioning at two time points (ages 5-6 and 10-11 years) that were linked with administrative data from government departments of health, child protection, and education for 19,087 children and their parents. Latent profile analyses were used to identify socio-emotional and cognitive profiles at each time point, and latent transition analyses were used to determine the probability and potential moderators of transition between profiles at each age. Three developmental profiles were identified in early childhood, reflecting typically developing, emotionally vulnerable, and cognitively vulnerable children, respectively; two profiles were identified in middle childhood, reflecting typically developing and vulnerable children. Child's sex, child protection services contact, parental mental illness, and parental offending influenced children's transitions between different vulnerability profiles, with the strongest effects for parental mental illness and child protection contact. Early detection of vulnerable children and factors promoting resilience are important steps in directing future health and social policy, and service planning for vulnerable children.Patrycja J. Piotrowska, Tyson Whitten, Stacy Tzoumakis, Kristin R. Laurens, Ilan Katz, Vaughan J. Carr, Felicity Harris, Melissa J. Gree

    Forecasting childhood adversities from conditions of birth

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    First published: 02 February 2022BACKGROUND: Childbirth presents an optimal time for identifying high-risk families to commence intervention that could avert various childhood health and social adversities. OBJECTIVE: We sought to establish the minimum set of exposures required to accurately predict a range of adverse childhood outcomes up to the age of 13 years, from a set of 14 individual and familial risk exposures evident at the time of birth. METHODS: Participants were 72,059 Australian children and their parents drawn from a multi-register population cohort study (data spanning 1994-2018). Risk exposures included male sex, young mother (aged ≤21 years), no (or late first; >16 weeks) antenatal visit, maternal smoking during pregnancy, small for gestational age, preterm birth, pregnancy complications (any of hypertension, diabetes mellitus, gestational diabetes or pre-eclampsia), >2 previous pregnancies of ≥20 weeks, socio-economic disadvantage, prenatal child protection notification, and maternal or paternal mental disorder or criminal offending history. Individual outcomes included early childhood developmental vulnerability (age 5 years), sustained educational underachievement (age 8 and 10 years), mental disorder diagnoses, substantiated childhood maltreatment, and contact with the police as a victim or person-of-interest up to age 13-14 years. RESULTS: Risk exposures at birth predicted individual childhood outcomes with fair to excellent accuracy: the area under the receiver operating characteristic curves ranged between 0.60 (95% CI 0.58, 0.62) for childhood mental disorder and 0.83 (95% CI 0.82, 0.85) for substantiated child maltreatment. The presence of five or more exposures characterised 12-25% of children with one or more adverse outcomes and showed high predictive certainty for models predicting multiple outcomes, which were apparent in 9% of the population. CONCLUSIONS: Up to a quarter of the neonatal population at risk of multiple adverse outcomes can be detected at birth, with implications for population health screening. However, cautious implementation of these models is warranted, given their relatively low positive predictive values.Melissa J. Green, Oliver J. Watkeys, Maina Kariuki, Gabrielle Hindmarsh, Tyson Whitten, Kimberlie Dean ... et al

    Increased incidence of childhood mental disorders following exposure to early life infection

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    Early life exposure to infectious diseases confers risk for adult psychiatric disorders but relatively few human population studies have examined associations with childhood mental disorder. Here we examined the effects of exposure to maternal infection during pregnancy, and child infectious diseases in early childhood (birth to age 4 years), in relation to first mental disorder diagnosis (age 5–13 years). The study sample comprised 71,841 children represented in a population cohort of children in New South Wales, Australia, followed from birth to early adolescence via linkage of administrative registers. Childhood exposure to infectious disease was determined during the prenatal period (i.e., maternal infection during gestation), and in early childhood (between birth and age 4 years) using the NSW Ministry of Health Admitted Patients data collection. Days to first diagnosis with a mental disorder was determined from recorded diagnoses between age 5–13 years in the NSW Ministry of Health’s Admitted Patients, Emergency Department and Mental Health Ambulatory data collections. While crude hazard ratios for both prenatal infection and childhood infection exposures indicated significantly earlier diagnosis with mental disorders associated with both of these risk factors, only childhood infection exposure was associated with higher adjusted hazard ratios (aHR) for any diagnoses (aHR = 1.21, 95% CI = 1.11–1.32), externalising disorders (aHR = 1.45, 95% CI 1.18–1.79) and developmental disorders (aHR = 1.82, 95% CI 1.49–2.22) when the effects of maternal and early childhood (age < 5 years) mental disorders were taken into account. Exposure to infectious diseases during early childhood, but not prenatal infection exposure, appears to be associated with earlier diagnosis of mental disorders in childhood.Melissa J. Green, Oliver J. Watkeys, Tyson Whitten, Catherine Thomas, Maina Kariuki, Kimberlie Dean, Kristin R. Laurens, Felicity Harris, Vaughan J. Car

    Cohort Profile: the New South Wales Child Development Study (NSW-CDS)-wave 2 (child age 13 years)

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    The New South Wales Child Development Study (NSW-CDS) was established to enable a life course epidemiological approach to identifying risk and protective factors for childhood and adolescent-onset mental health problems, and other adverse outcomes (e.g. educational underachievement, welfare dependence, criminality). The study methodology entails repeated waves of record linkage for a population of Australian children in the state of NSW, funded by competitive funding awards (see Funding), and conducted in partnership with multiple NSW government departments. Table 1 summarizes the study phases (waves of record linkage) and measurements.Melissa J Green, Felicity Harris, Kristin R Laurens, Maina Kariuki, Stacy Tzoumakis ... Sally Brinkman ... et al
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