115 research outputs found
Variation in male body size and reproductive allocation in the leafcutter ant <em>Atta colombica</em>:estimating variance components and possible trade-offs
Sex, size and isotopes: cryptic trophic ecology of an apex predator, the white shark Carcharodon carcharias
Demographic differences in resource use are key components of population and species ecology across the animal kingdom. White sharks (Carcharodon carcharias) are migratory, apex predators, which have undergone significant population declines across their range. Understanding their ecology is key to ensuring that management strategies are effective. Here, we carry out the first stable isotope analyses of free-swimming white sharks in South Africa. Biopsies were collected in Gansbaai (34.5805°S, 19.3518°E) between February and July 2015. We used Stable Isotope Bayesian Ellipsis in R and traditional statistical analyses to quantify and compare isotopic niches of male and female sharks of two size classes, and analyse relationships between isotopic values and shark length. Our results reveal cryptic trophic differences between the sexes and life stages. Males, but not females, were inferred to feed in more offshore or westerly habitats as they grow larger, and only males exhibited evidence of an ontogenetic niche shift. Lack of relationship between δ13C, δ15N and female shark length may be caused by females exhibiting multiple migration and foraging strategies, and a greater propensity to travel further north. Sharks  3 m, drivers of which may include individual dietary specialisation and temporal factors. The differences in migratory and foraging behaviour between sexes, life stages, and individuals will affect their exposure to anthropogenic threats, and should be considered in management strategies
Reduction in Urinary Arsenic with Bottled-water Intervention
The study was conducted to measure the effectiveness of providing bottled water in reducing arsenic exposure. Urine, tap-water and toenail samples were collected from non-smoking adults residing in Ajo (n=40) and Tucson (n=33), Arizona, USA. The Ajo subjects were provided bottled water for 12 months prior to re-sampling. The mean total arsenic (μg/L) in tap-water was 20.3±3.7 in Ajo and 4.0±2.3 in Tucson. Baseline urinary total inorganic arsenic (μg/L) was significantly higher among the Ajo subjects (n=40, 29.1±20.4) than among the Tucson subjects (n=32, 11.0±12.0, p<0.001), as was creatinine-adjusted urinary total inorganic arsenic (μg/g) (35.5±25.2 vs 13.2±9.3, p<0.001). Baseline concentrations of arsenic (μg/g) in toenails were also higher among the Ajo subjects (0.51±0.72) than among the Tucson subjects (0.17±0.21) (p<0.001). After the intervention, the mean urinary total inorganic arsenic in Ajo (n=36) dropped by 21%, from 29.4±21.1 to 23.2±23.2 (p=0.026). The creatinine-adjusted urinary total inorganic arsenic and toenail arsenic levels did not differ significantly with the intervention. Provision of arsenic-free bottled water resulted in a modest reduction in urinary total inorganic arsenic
Contextualising the pervasive impact of macroeconomic austerity on prison health in England: A qualitative study among international policymakers
Background: Prisons offer the state the opportunity to gain access to a population that is at particularly high risk of ill-health. Despite the supportive legal and policy structures surrounding prison rehabilitation, the oppressive nature of the austerity policy in England threatens its advanced improvement.Methods: Using grounded theory methodology, this is the first interdisciplinary qualitative study to explore the impact of macroeconomic austerity on prison health in England from the perspective of 29 international prison policymakers.Results: The far-reaching impact of austerity in England has established a regressive political system that shapes the societal attitude towards social issues, which has exacerbated the existing poor health of the prisoners. Austerity has undermined the notion of social collectivism, imposed a culture of acceptance among prison bureaucrats and the wider community, and normalised the devastating impacts of prison instability. These developments are evidenced by the increasing levels of suicide, violence, radicalisation and prison gangs among prisoners, as well as the imposition of long working hours and the high levels of absenteeism among prison staff.Conclusions: This study underscores an important and yet unarticulated phenomenon that despite being the fifth largest economy in the world, England’s poorest, marginalised and excluded population continues to bear the brunt of austerity. Reducing the prison population, using international obligations as minimum standards to protect prisoners’ right to health and providing greater resources would create a more positive and inclusive system, in line with England’s international and domestic commitments to the humane treatment of all people
Elemental trace analysis in biological samples by high resolution inductively coupled plasma mass spectrometry
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