910 research outputs found

    Levels of Cadmium, Lead, Mercury and 137caesium in Caribou (Rangifer tarandus) Tissues from Northern Québec

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    Levels of cadmium (Cd), lead (Pb) and total mercury (Hg) were assessed in samples of muscle, kidney, and liver from caribou (Rangifer tarandus; n = 317) harvested in two regions of northern Québec between 1994 and 1996. Levels of 137caesium (137Cs) were also examined in muscle samples. Log concentration of the three metals varied significantly among tissues and was lowest in diaphragm muscle and highest in kidneys and liver. Mean Cd (wet weight, w.w.) concentration was 0.01 µg/g in muscle, 7.69 µg/g in kidneys and 1.13 µg/g in liver. Levels of Cd exceeded tolerance thresholds for human consumption in nearly all kidney samples and in nearly half the liver samples. Mean Pb concentration (w.w.) was 0.05 µg/g in muscle, 0.26 µg/g in kidneys and 0.95 µg/g in liver, with few samples exceeding consumption thresholds. Mean total Hg concentration (w.w.) in muscle was 0.03 µg/g, 1.26 µg/g in kidneys and 0.67 µg/g in liver, with concentrations exceeding consumption thresholds in most kidney samples and nearly half the liver samples. Regional differences occurred in log concentration of the three metals for most tissues, with the western region consistently showing higher values. Mean log Cd and Pb concentrations increased with age in kidneys, but log Pb decreased with age in muscle samples. Interactions between month of collection and sex and region also occurred for some metals in some tissues. Mean level of 137Cs in muscle samples was 94.7 Bq/kg, never exceeding the acceptable limit for human consumption.On a mesuré les niveaux de cadmium (Cd), de plomb (Pb) et de mercure total (Hg) dans des échantillons de muscle, de rein et de foie de caribous (Rangifer tarandus; n = 317) prélevés dans deux régions du Québec nordique entre 1994 et 1996. On a en outre étudié les niveaux de césium 137 (137Cs) dans des échantillons musculaires. Les concentrations enregistrées des trois métaux montraient d'importantes variations parmi les divers tissus et étaient les plus faibles dans le muscle du diaphragme et les plus élevées dans le rein et le foie. La concentration moyenne de Cd (poids frais, p.f.) était de 0,01 µg/g dans le muscle, de 7,69 µg/g dans le rein et de 1,13 µg/g dans le foie. Les niveaux de Cd dépassaient les seuils de tolérance pour la consommation humaine dans presque tous les échantillons de rein et dans près de la moitié des échantillons de foie. La concentration moyenne (p.f.) de Pb était de 0,05 µg/g dans le muscle, de 0,26 µg/g dans le rein et de 0,95 µg/g dans le foie, avec peu d'échantillons dépassant les seuils de consommation. La concentration moyenne de Hg total (p.f.) dans le muscle était de 0,03 µg/g, de 1,26 µg/g dans le rein et de 0,67 µg/g dans le foie, avec des concentrations qui dépassaient les seuils de consommation dans la plupart des échantillons de rein et presque la moitié des échantillons de foie. Des différences régionales sont apparues dans les concentrations enregistrées des trois métaux pour la plupart des tissus, la zone occidentale montrant constamment des valeurs plus élevées. Avec l'âge, les concentrations moyennes enregistrées pour le Cd et le Pb augmentaient dans le rein, alors que celles de Pb diminuaient dans le muscle. Des interactions entre le mois des prélèvements, le sexe et la région se produisaient aussi avec certains métaux et certains tissus. Le niveau moyen de 137Cs dans les échantillons musculaires était de 94,7 Bq/kg, ne dépassant jamais la limite acceptable pour la consommation humaine

    Neuropsychological and functional outcomes in recent-onset major depression, bipolar disorder and schizophrenia-spectrum disorders: a longitudinal cohort study

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    Functional disability is the lead contributor to burden of mental illness. Cognitive deficits frequently limit functional recovery, although whether changes in cognition and disability are longitudinally associated in recent-onset individuals remains unclear. Using a prospective, cohort design, 311 patients were recruited and assessed at baseline. One hundred and sixty-seven patients met eligibility criteria (M = 21.5 years old, s.d. = 4.8) and returned for follow-up (M = 20.6 months later, s.d. = 7.8). Two-hundred and thirty participants were included in the final analysis, comprising clinically stable patients with major depression (n = 71), bipolar disorder (BD; n = 61), schizophrenia-spectrum disorders (n = 35) and 63 healthy controls. Neuropsychological functioning and self-rated functional disability were examined using mixed-design, repeated-measures analysis, across diagnoses and cognitive clusters, covarying for relevant confounds. Clinical, neuropsychological and functional changes did not differ between diagnoses (all P40.05). Three reliable neuropsychological subgroups emerged through cluster analysis, characterized by psychomotor slowing, improved sustained attention, and improved verbal memory. Controlling for diagnosis and changes in residual symptoms, clusters with improved neuropsychological functioning observed greater reductions in functional disability than the psychomotor slowing cluster, which instead demonstrated a worsening in disability (Po0.01). Improved sustained attention was independently associated with greater likelihood of follow-up employment (Po0.01). Diagnosis of BD uniquely predicted both follow-up employment and independent living. Neuropsychological course appears to be independently predictive of subjective and objective functional outcomes. Importantly, cognitive phenotypes may reflect distinct pathophysiologies shared across major psychiatric conditions, and be ideal targets for personalized early intervention

    MOLECULAR AGENTS FOR TARGETED IMAGING AND THERAPY Trends and Concepts in Agent Development

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    Abstract: Molecular Imaging allows the visualization of biological processes in vivo, offering new chances for healthcare with respect to early diagnosis and improved therapy. The new field of molecular imaging has been boosted by more sensitive imaging systems and the emergence of targeted imaging agents that home in on molecules of interest. This chapter describes the principles of molecular imaging and the different strategies to design targeted agents. Each imaging modality offers certain strong points but also shortcomings, which impact targeted agent design and their potential area of application

    Climate and soil type together explain the distribution of microendemic species in a biodiversity hotspot

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    The grasshopper genus Caledonula, endemic to New Caledonia, was studied to understand the evolution of species distributions in relation to climate and soil types. Based on a comprehensive sampling of 80 locations throughout the island, the genus was represented by five species, four of which are new to science, of which three are described here. All the species have limited distributions in New Caledonia. Bioclimatic niche modelling shows that all the species were found in association with a wet climate and reduced seasonality, explaining their restriction to the southern half of the island. The results suggest that the genus was ancestrally constrained by seasonality. A molecular phylogeny was reconstructed using two mitochondrial and two nuclear markers. The partially resolved tree showed monophyly of the species found on metalliferous soils, and molecular dating indicated a rather recent origin for the genus. Adaptation to metalliferous soils is suggested by both morphological changes and radiation on these soils. The genus Caledonula is therefore a good model to understand the origin of microendemism in the context of recent and mixed influences of climate and soil type
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