117 research outputs found
Assessment of the water soluble ionic species of suspended particulate matter, collected at a coastal spot, De Haan, Belgium
Chemical characterisation of suspended particulate matter (SPM) is very useful for broadening the knowledge concerning processes which are active in the atmosphere (e.g. Lin, 2002). Continental air-masses were found to contain high levels of anthropogenic emitted species, while these levels decreased when the influence changed to an oceanic atmosphere. The high levels of NH4 +, NO3 - and non-sea-salt (NSS) SO4 2- in the fine SPM fraction of continental air-masses (0.38, 0.15μg.N.m-3 and 0.59μg.m-3, respectively) stresses the importance of secondary aerosol formation as a source for SPM. The dominant appearances of Na+, Cl-, Mg2+ and Ca2+ in coarse maritime air masses show the presence of sea-salts and soil dust in the atmosphere at the coastal region. Neutralisation ratios higher than unity (1.20-1.59) for the fine SPM fraction suggested an excess of NH4 +, which was most probably present in the form of NH4Cl due neutralisation of HCl. The latter was formed in atmospheric reactions with sea-salt particles (Kadowaki, 1977), during which HCl escapes (0.13 and 0.58% lost sea-salt chloride for winter and summer, respectively). Correlation analysis showed that warm and dry summer conditions eliminated some influence of sea-salts on atmospheric processes, that where found to be active during winter. NSS SO4 2- was the dominant S-contributor in the fine fraction (83%). During winter, a total SOR value of 0.61 was reached, while summer gave a significant lower value (0.24). These values classified the sampling-site at the Belgian coast as a combined receptor-source area, accepting pollution from the continent and its local surroundings (Shaw and Rodhe, 1982)
Occurrence and profiles of PCBs and PBDEs in harbour seals and harbour porpoises from the southern North Sea
Harbour porpoises (Phocoena phocoen) and harbour seals (Phoca vitulina), two representative top coastal pollution. Concentrations of sum PCBs were 1-2 orders of magnitude higher than concentrations of sum PBDEs (with median values of 23.1 μg.g- lw (lipid weight) and 12.4 μ.g-1 lw for sum PCBs and 0.33 μ.g- lw and 0.76 μ.g-1 lw for sum PBDEs in harbour seals and harbour porpoises respectively) and were highly dependent of age group and gender. For both species, the highest PCB concentrations were observed in adult males as the result of accumulation for years and years, while the highest PBDE concentrations were measured in juveniles probably due to better developed metabolic capacities for these congeners with age in adults. Results for PCBs were higher than observations in harbour seals and porpoises from other areas, while results for PBDEs were comparable indicating that the North Sea is a highly contaminated area. Relative PCB and PBDE profiles were constructed to compare metabolic capacities between harbour seals and porpoises. A higher contribution of lower chlorinated and nonpersistent congeners, such as CB 52, CB 95, CB 101, CB 118 and CB 149 indicated that harbour porpoises are unable to metabolize these compounds. Similar to PCBs, higher contributions of other PBDEs than BDE 47 were observed in harbour porpoises, suggesting that this species has difficulties to metabolize these congeners. In contrast, harbour seals showed a higher ability to metabolize PCBs and PBDEs
Time spent with cats is never wasted: Lessons learned from feline acromegalic cardiomyopathy, a naturally occurring animal model of the human disease
<div><p>Background</p><p>In humans, acromegaly due to a pituitary somatotrophic adenoma is a recognized cause of increased left ventricular (LV) mass. Acromegalic cardiomyopathy is incompletely understood, and represents a major cause of morbidity and mortality. We describe the clinical, echocardiographic and histopathologic features of naturally occurring feline acromegalic cardiomyopathy, an emerging disease among domestic cats.</p><p>Methods</p><p>Cats with confirmed hypersomatotropism (IGF-1>1000ng/ml and pituitary mass; n = 67) were prospectively recruited, as were two control groups: diabetics (IGF-1<800ng/ml; n = 24) and healthy cats without known endocrinopathy or cardiovascular disease (n = 16). Echocardiography was performed in all cases, including after hypersomatotropism treatment where applicable. Additionally, tissue samples from deceased cats with hypersomatotropism, hypertrophic cardiomyopathy and age-matched controls (n = 21 each) were collected and systematically histopathologically reviewed and compared.</p><p>Results</p><p>By echocardiography, cats with hypersomatotropism had a greater maximum LV wall thickness (6.5mm, 4.1–10.1mm) than diabetic (5.9mm, 4.2–9.1mm; Mann Whitney, p<0.001) or control cats (5.2mm, 4.1–6.5mm; Mann Whitney, p<0.001). Left atrial diameter was also greater in cats with hypersomatotropism (16.6mm, 13.0–29.5mm) than in diabetic (15.4mm, 11.2–20.3mm; Mann Whitney, p<0.001) and control cats (14.0mm, 12.6–17.4mm; Mann Whitney, p<0.001). After hypophysectomy and normalization of IGF-1 concentration (n = 20), echocardiographic changes proved mostly reversible. As in humans, histopathology of the feline acromegalic heart was dominated by myocyte hypertrophy with interstitial fibrosis and minimal myofiber disarray.</p><p>Conclusions</p><p>These results demonstrate cats could be considered a naturally occurring model of acromegalic cardiomyopathy, and as such help elucidate mechanisms driving cardiovascular remodeling in this disease.</p></div
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