Trace metal distribution in the bed, bank and suspended sediment of the Ravensbourne River and its implication for sediment monitoring in an urban river

Purpose This study aims to identify a suitable sediment compartment for sediment quality monitoring by: (a) studying the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the bed, bank and suspended sediment compartments of the Ravensbourne River to establish any differences in trace metal concentrations with compartment; (b) determining the influence of sediment particle size fractions ( 0.05) in the concentrations of metals between the suspended sediment and the < 63 μm bed sediment fraction, but there was a significant difference (p < 0.05) between the suspended sediment and the < 63 μm bank sediment fraction. There were also significant differences between the concentrations of metals in the < 63 μm and the 63 μm–2 mm fractions. Generally, the Ravensbourne River did not comply with the draft UK sediment quality guidelines for the metals analysed. Conclusions This study shows the importance of identifying a suitable sediment compartment to sample for compliance with sediment quality standards. The bed and suspended sediments are the most widely used sediment compartments for sediment monitoring, but collecting sufficient mass of the < 63 μm sediment fraction for monitoring presents a challenge for urban gravel bed rivers like the Ravensbourne River. It seems appropriate to establish individual monitoring regimes for different rivers

Developing a Bayesian framework for stock assessment and decision analysis of the red sea urchin fishery in Baja California, Mexico

The red sea urchin (Strongylocentrotus franciscanus) fishery is of importance to the economy of Baja California (Mexico). The commercial fishery started in the early 1970s as a result of expanding export markets, but has experienced substantial decline in landings and abundance since 1986. Fishery-independent surveys have not been conducted for all fishing areas, thus CPUE and catch data were used to conduct a stock assessment and decision analysis for the red sea urchin stock. The red sea urchin population dynamics was described with the Schaefer biomass dynamic model. Bayesian approaches were used for the estimation of the model parameters and for projecting the population dynamics of the species under different management scenarios, including constant harvest rate and constant catch strategies. This study suggests that the current stock is only 17% of the virgin stock biomass and that, for a constant catch policy, a 10% increase in the current catch rate could potentially cause the collapse of the fishery in 20 years. Simulation results suggested that a constant harvest rate between 15% and 25% would cause the population to recover and maximize the catch in 2024. Higher harvest rate levels would increase the probability of the biomass being less than 40% of the population carrying capacity.

Atmospheric pressure plasma surface treatment of thermoplastic composites for bonded joints

Glass fiber reinforced polypropylene samples were treated by an atmospheric pressure plasma jet using a rotary nozzle, in order to improve adhesive properties of the material surface. Thereby, the influence of the most significant operational parameters of the plasma treatment was studied. These parameters are e.g. the distance between the nozzle and the treated substrate, and the total plasma exposure time, varied by the axial velocity of the plasma jet. Two different parameter sets were selected to be compared in the present study. The surface properties after the plasma treatment were investigated by atomic force microscopy in combination with the contact angle measurements followed by the surface free energy calculation according to the OWRK method. The results were compared with those of the untreated samples to evaluate the induced effects. The surface free energy and hence the wettability were found to be increased significantly by both treatments. The surface topography was changed also in both cases, whereas one of the used parameter sets resulted in a higher roughness comparing to the untreated reference sample, and another one reduced it. Moreover, the adhesion properties of the treated surfaces were evaluated by lap shear tests. All treated samples exhibit a significant increased bonding strength in comparison to the untreated substrates. This improvement can be related both to the changes of the surface topography, induced by the thermal component of the plasma, and the cleaning and activation effects caused by the reactive plasma species during the treatment. However, significant differences concerning the total bonding strength were found between the used process parameter sets. Thus, a higher intensity of the plasma treatment led to a lower resistance of the final bond. In this case, the polymer surface seems to be partly degraded, forming a weak boundary layer, which indicates an overtreatment of the material

Myocardial expression of survivin, an apoptosis inhibitor, in aging and heart failure. An experimental study in the spontaneously hypertensive rat

Background: Apoptosis plays a major role in the transition to heart failure (HF) in systemic hypertension although the underlying mechanisms are still unclear. The aim of this study was to determine the relationship between apoptosis, left ventricular remodeling, heart failure and the myocyte expression of survivin, an inhibitor of apoptosis. Methods: Spontaneously hypertensive rats (SHR) were used as a model of hypertensive cardiopathy, and Wistar Kyoto Stars rats (WKY) were used as controls. Animals were allowed to survive up to 18 months of age. The animals underwent echocardiography (EDD, ESD and FS were measured). The median section of the heart was processed for in situ end-labeling of DNA fragmentation (TUNEL) and for survivin expression by immunohistochemistry. Results: All SHR presented features of adverse cardiac remodeling. Apoptotic cells were increased in SHR compared with WKY, measured as apoptotic cells per high power field (1.08 ± 0.43 vs. 0.27 ± 0.15, P < 0.001), and as apoptotic rate (0.16 ± 0.06% vs. 0.04 ± 0.02%, P < 0.001). The incidence of apoptosis showed a positive correlation with unfavorable ventricular remodeling, assessed by echocardiogram. Survivin expression was found in all cases, but the survivin expression index was significantly lower in SHR vs. WKY (43 ± 40% vs. 86 ± 18%, respectively, P = 0.014). Moreover the survivin expression index was inversely correlated with features of adverse remodeling (i.e., Heart Weight, R = - 0.79, P < 0.001) and with apoptosis (i.e., apoptotic rate, R = - 0.52, P = 0.050). Conclusion: Survivin myocardial expression in aging SHR is associated with reduced apoptosis and more favorable cardiac remodeling. Modulation of this pathway may prove beneficial in preventing pressure overload cardiac remodeling and heart failure. © 2005 Elsevier Ireland Ltd. All rights reserved

613 cases of splenic rupture without risk factors or previously diagnosed disease: a systematic review

Background Rupture of the spleen in the absence of trauma or previously diagnosed disease is largely ignored in the emergency literature and is often not documented as such in journals from other fields. We have conducted a systematic review of the literature to highlight the surprisingly frequent occurrence of this phenomenon and to document the diversity of diseases that can present in this fashion. Methods Systematic review of English and French language publications catalogued in Pubmed, Embase and CINAHL between 1950 and 2011. Results We found 613 cases of splenic rupture meeting the criteria above, 327 of which occurred as the presenting complaint of an underlying disease and 112 of which occurred following a medical procedure. Rupture appeared to occur spontaneously in histologically normal (but not necessarily normal size) spleens in 35 cases and after minor trauma in 23 cases. Medications were implicated in 47 cases, a splenic or adjacent anatomical abnormality in 31 cases and pregnancy or its complications in 38 cases. The most common associated diseases were infectious (n = 143), haematologic (n = 84) and non-haematologic neoplasms (n = 48). Amyloidosis (n = 24), internal trauma such as cough or vomiting (n = 17) and rheumatologic diseases (n = 10) are less frequently reported. Colonoscopy (n = 87) was the procedure reported most frequently as a cause of rupture. The anatomic abnormalities associated with rupture include splenic cysts (n = 6), infarction (n = 6) and hamartomata (n = 5). Medications associated with rupture include anticoagulants (n = 21), thrombolytics (n = 13) and recombinant G-CSF (n = 10). Other causes or associations reported very infrequently include other endoscopy, pulmonary, cardiac or abdominal surgery, hysterectomy, peliosis, empyema, remote pancreato-renal transplant, thrombosed splenic vein, hemangiomata, pancreatic pseudocysts, splenic artery aneurysm, cholesterol embolism, splenic granuloma, congenital diaphragmatic hernia, rib exostosis, pancreatitis, Gaucher's disease, Wilson's disease, pheochromocytoma, afibrinogenemia and ruptured ectopic pregnancy. Conclusions Emergency physicians should be attuned to the fact that rupture of the spleen can occur in the absence of major trauma or previously diagnosed splenic disease. The occurrence of such a rupture is likely to be the manifesting complaint of an underlying disease. Furthermore, colonoscopy should be more widely documented as a cause of splenic rupture