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Lesser Role (lesser + role)
Selected AbstractsModelling potential spawning habitat of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Bay of BiscayFISHERIES OCEANOGRAPHY, Issue 1 2007BENJAMIN PLANQUE Abstract Large amplitude variations in recruitment of small pelagic fish result from interactions between a fluctuating environment and population dynamics processes such as spawning. The spatial extent and location of spawning, which is critical to the fate of eggs and larvae, can vary strongly from year to year, as a result of changing population structure and environmental conditions. Spawning habitat can be divided into ,potential spawning habitat', defined as habitat where the hydrographic conditions are suitable for spawning, ,realized spawning habitat', defined as habitat where spawning actually occurs, and ,successful spawning habitat', defined as habitat from where successful recruitment has resulted. Using biological data collected during the period 2000,2004, as well as hydrographic data, we investigate the role of environmental parameters in controlling the potential spawning habitat of anchovy and sardine in the Bay of Biscay. Anchovy potential spawning habitat appears to be primarily related to bottom temperature followed by surface temperature and mixed-layer depth, whilst surface and bottom salinity appear to play a lesser role. The possible influence of hydrographic factors on the spawning habitat of sardine seems less clear than for anchovy. Modelled relationships between anchovy and sardine spawning are used to predict potential spawning habitat from hydrodynamical simulations. The results show that the seasonal patterns in spawning are well reproduced by the model, indicating that hydrographic changes may explain a large fraction of spawning spatial dynamics. Such models may prove useful in the context of forecasting potential impacts of future environmental changes on sardine and anchovy reproductive strategy in the north-east Atlantic. [source] Redistribution or horizontal equity in Hong Kong's mixed public,private health system: a policy conundrumHEALTH ECONOMICS, Issue 1 2009Gabriel M. Leung Abstract We examine the distributional characteristics of Hong Kong's mixed public,private health system to identify the net redistribution achieved through public spending on health care, compare the income-related inequality and inequity of public and private care and measure horizontal inequity in health-care delivery overall. Payments for public care are highly concentrated on the better-off whereas benefits are pro-poor. As a consequence, public health care effects significant net redistribution from the rich to the poor. Public care is skewed towards the poor in part not only because of allocation according to need but also because the rich opt out of the public sector and consume most of the private care. Overall, there is horizontal inequity favouring the rich in general outpatient care and (very marginally) inpatient care. Pro-rich bias in the distribution of private care outweighs the pro-poor bias of public care. A lesser role for private finance may improve horizontal equity of utilisation but would also reduce the degree of net redistribution through the public sector. Copyright © 2008 John Wiley & Sons, Ltd. [source] Disease-specific Helicobacter pylori Virulence Factors: The Unfulfilled PromiseHELICOBACTER, Issue S1 2000David Y. Graham A number of putative virulence factors for Helicobacter pylori have been identified including cagA, vacA and iceA. The criteria for a true virulence factor includes meeting the tests of biologically plausibility with the associations being both experimentally and epidemiologically consistent. Although disease-specific associations have been hypothesized/claimed, there are now sufficient data to conclusively state that none of these putative virulence factors have disease specificity. CagA has been claimed to be associated with increased mucosal IL-8 and inflammation, increased density of H. pylori in the antrum, duodenal ulcer (DU), gastric cancer, and protection against Barrett's cancer. Only the increase in IL-8/inflammation is direct and substantiated. Different H. pylori strains with functional cag pathogenicity islands do not vary in virulance as it has been shown that mucosal IL-8 levels are proportional to the number of cagA +H. pylori independent of the disease from which the H. pylori were obtained. It is now known that the density of either cagA + and cagA,H. pylori in the antrum of patients with H. pylori gastritis is the same. In contrast, the mean density of H. pylori in the antrum in DU is greater than in the antrum of patients with H. pylori gastritis. Of interest, the density of H. pylori is higher in the corpus of patients with H. pylori gastritis than those with DU, suggesting that acid secretion plays a critical role in these phenomena. The presence of a functional cag pathogenicity island increases inflammation and it is likely that any factor that results in an increase in inflammation also increases the risk of a symptomatic outcome. Nevertheless, the presence of a functional cag pathogenicity island has no predictive value for the presence, or the future development of a clinically significant outcome. The hypothesis that iceA has disease specificity has not been confirmed and there is currently no known biological or epidemiological evidence for a role for iceA as a virulence factor in H. pylori -related disease. The claim that vacA genotyping might prove clinically useful, e.g. to predict presentation such as duodenal ulcer, has been proven wrong. Analysis of the worldwide data show that vacA genotype s1 is actually a surrogate for the cag pathogenicity island. There is now evidence to suggest that virulence is a host-dependent factor. The pattern of gastritis has withstood the test of time for its relation to different H. pylori -related diseases (e.g. antral predominant gastritis with duodenal ulcer disease). The primary factors responsible for the different patterns of gastritis in response to an H. pylori infection are environmental (e.g. diet), with the H. pylori strain playing a lesser role. Future studies should work to eliminate potential bias before claiming disease associations. Controls must exclude regional or geographic associations related to the common strain circulation and not to the outcome. The authors must also control for both the presence of the factor and for the disease association. The study should be sufficiently large and employ different diseases and ethnic groups for the results to be robust. The findings in the initial sample (data derived hypothesis) should be tested in a new group (hypothesis testing), preferably from another area, before making claims. Finally, it is important to ask whether the results are actually a surrogate for another marker (e.g. vacA s1 for cagA) masquerading for a new finding. Only the cag pathogenicity island has passed the tests of biological plausibility (increased inflammation) and experimental and epidemiological consistency. [source] SUBJECTIVE PROBABILITIES IN GAMES: AN APPLICATION TO THE OVERBIDDING PUZZLE,INTERNATIONAL ECONOMIC REVIEW, Issue 4 2009Olivier Armantier This article illustrates how the joint elicitation of subjective probabilities and preferences may help us understand behavior in games. We conduct an experiment to test whether biased probabilistic beliefs may explain overbidding in first-price auctions. The experimental outcomes indicate that subjects underestimate their probability of winning the auction, and indeed overbid. When provided with feedback on the precision of their predictions, subjects learn to make better predictions, and to curb significantly overbidding. The structural estimation of different behavioral models suggests that biased probabilistic beliefs are a driving force behind overbidding, and that risk aversion plays a lesser role than previously believed. [source] Analysis of green pit viper (Trimeresurus alborabris) venom protein by LC/MS-MSJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2008Suphan Soogarun Green pit viper venom has major effect on the hematological system having a thrombin-like effect. Thus, this study is designed to analyze the composition of Trimeresurus albolabris venom by performing gel filtration and LC/MS-MS. The purified protein was then digested by trypsin, and the tryptic fragments were analyzed by iontrap spectrophotometry. This study found four types of proteins, namely jerdonitin, stejaggregin-A , chain-1, stejnobin, and stejnihagin-A, as the components of T. albolabris venom. All of these toxins played a greater or lesser role in clot formation or otherwise contributed to cross-reactions in antivenom production. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:225,229, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20232 [source] Role of astrocytes in trimethyltin neurotoxicityJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2001Palur G. Gunasekar Abstract Although the neurotoxicity of trimethyltin (TMT) is well known, mechanisms are still not clear. Glia have been proposed to mediate the toxic action of TMT on nerve cells. Accordingly, the effects of TMT were tested in primary neuronal cultures from rat cerebellum and compared to effects in astrocytes and mixed cultures. Neuronal damage observed following TMT exposure was less in the presence of astrocytes and astrocytes alone were resistant to TMT. Thus, astrocytes have a protective effect against TMT-induced neurotoxicity. TMT caused an oxidative stress in granule cell cultures involving a variety of oxidative species ((O2),,, H2O2, NO), but astrocytes were less sensitive to TMT-induced oxidative species generation. Antioxidants, glutathione and 7-nitroindazole attenuated neuronal cell death induced by TMT. It appears that oxidative stress mediates a large part of the destructive action of TMT in neuronal cultures. The presence of astrocytes appears to modulate TMT-induced oxidative stress so that TMT causes only a small increase in lipid peroxidation in mouse brain after systemic administration. Thus, TMT induces a pronounced oxidative stress in cultured neurons, but when astrocytes are present, oxidative species play a lesser role in the neurotoxic action of TMT. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:256,262, 2001 [source] Are differences in seed mass among species important in structuring plant communities?OIKOS, Issue 3 2002Evidence from analyses of spatial, temporal variation in dune-annual populations We analyse the population and spatial structures of coastal annual-plant communities, across ten dunes and three years, to explore the role of seed mass in structuring these communities. One suggestion is that annual-plant communities are structured by competition-colonization trade-offs driven by difference among species in seed-allocation strategies, while another perspective is that seed mass influences the ways in which species respond to environmental variation. In support of the competition-colonization trade-off, the two largest-seeded species found on the dunes (Erodium cicutarium and Geranium molle) were negatively associated with the other guild members at the 10-mm scale in 1995, suggesting they locally excluded smaller-seeded species in that year (when population densities were high). In support of the environmental response hypothesis, populations of annual plants declined between 1995 and 1996 on eight of the ten dunes, underscoring the importance of year-to-year environmental fluctuations in determining population sizes. The species that became relatively uncommon also became more aggregated in space, and this effect was most pronounced among the small-seeded species. Thus, small-seeded species may be forced to retreat into refuges when conditions are unfavourable, where reduced frequencies of interspecific contacts may increase their chances of persistence. We also show that small-seeded species sometimes reach much higher population densities than larger-seeded species, consistent with earlier findings, but reason that this abundance/seed mass relationship could have resulted from either a competition-colonization trade-off or from different responses of small- and large-seeded species to environmental variation. We conclude that dune-annual species with contrasting seed masses respond differently to environmental variation, while the competition-colonization trade-off plays a lesser role in community dynamics than previously considered. [source] Medical and midwifery students: how do they view their respective roles on the labour ward?AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 4 2002Julie A Quinlivan ABSTRACT Background It has been suggested that much of the medical and midwifery student curricula on normal pregnancy and birth could be taught as a co-operative effort between obstetric and midwifery staff. One important element of a successful combined teaching strategy would involve a determination of the extent to which the students themselves identify common learning objectives. Aim The aim of the present study was to survey medical and midwifery students about how they perceived their respective learning roles on the delivery suite. Methods A descriptive cross-sectional survey study was undertaken. The study venue was an Australian teaching and tertiary referral hospital in obstetrics and gynaecology. Survey participants were medical students who had just completed a 10 week clinical attachment in obstetrics and gynaecology during the 5th year of a six year undergraduate medical curriculum and midwifery students undertaking a one year full-time (or two year part-time) postgraduate diploma in midwifery. Results Of 130 and 52 questionnaires distributed to medical and midwifery students, response rates of 72% and 52% were achieved respectively. The key finding was that students reported a lesser role for their professional colleagues than they identified for themselves. Some medical students lacked an understanding of the role of midwives as 8%, 10%, and 23% did not feel that student midwives should observe or perform a normal birth or neonatal assessment respectively. Of equal concern, 7%, 22%, 26% and 85% of student midwives did not identify a role for medical students to observe or perform a normal birth, neonatal assessment or provide advice on breastfeeding respectively. Summary Medical and midwifery students are placed in a competitive framework and some students may not understand the complementary role of their future colleagues. Interdisciplinary teaching may facilitate co-operation between the professions and improve working relationships. [source] The Mechanism of Formation of Amide-Based Interlocked Compounds: Prediction of a New Rotaxane-Forming MotifCHEMISTRY - A EUROPEAN JOURNAL, Issue 20 2004David A. Leigh Prof. Abstract Molecular modeling of four different reagent systems shows that the (free) energies of supramolecular interactions in the gas phase and in solution can explain the different reaction products (i.e., various sized macrocycles, catenanes, and linear oligomers) that are formed in classic amide-catenane-forming reactions. Self-assembly of the catenanes requires the formation of ordered intertwined chains and is driven by bifurcated hydrogen bonds, with , stacking only playing a lesser role. The understanding gained from the computational study was used to predict the possibility of a new rotaxane-forming system that does not permit catenane formation. The predictions were confirmed by the successful synthesis and characterization (including X-ray crystallography) of two novel rotaxanes. [source] | |||||||||||||