Population structure of graptolite assemblages

Graptolite rhabdosomes display a diverse suite of morphologies. The range of morphotypes present within most moderate to high diversity assemblages from the Ordovician and Silurian is similar, despite the different taxonomic composition of the faunas at different times. Survivorship analyses of graptolite faunas from the Ordovician and Silurian demonstrate strong similarities in the mortality rates of unrelated graptolites of similar functional morphology. It also shows a strong correlation of decreasing mortality rates amongst more mature colonies with increasing rhabdosome complexity. This similarity in both functional morphology and life history of graptolites suggests that they lived within a very stable planktic community structure

Propofol and children--what we know and what we do not know.

The pharmacokinetics of propofol are relatively well described in the pediatric population. Recent work has confirmed the validity of allometric scaling for predicting propofol disposition across different species and for describing pediatric ontogenesis. In the first year of life, allometric models require adjustment to reflect ontogeny of maturation. Pharmacodynamic data for propofol in children are scarcer, because of practical difficulties in data collection and the limitations of currently available depth of anesthesia monitors for pediatric use. Hence, questions relating to the comparative sensitivity of children to propofol, and differences in time to peak effect relative to adults, remain unanswered. K(eo) half-lives have been determined for pediatric kinetic models using time to peak effect techniques but are not currently incorporated into commercially available target-controlled infusion pumps

Stability of Steady Multi-Wave Configurations for the Full Euler Equations of Compressible Fluid Flow

We are concerned with the stability of steady multi-wave configurations for the full Euler equations of compressible fluid flow. In this paper, we focus on the stability of steady four-wave configurations that are the solutions of the Riemann problem in the flow direction, consisting of two shocks, one vortex sheet, and one entropy wave, which is one of the core multi-wave configurations for the two-dimensional Euler equations. It is proved that such steady four-wave configurations in supersonic flow are stable in structure globally, even under the BV perturbation of the incoming flow in the flow direction. In order to achieve this, we first formulate the problem as the Cauchy problem (initial value problem) in the flow direction, and then develop a modified Glimm difference scheme and identify a Glimm-type functional to obtain the required BV estimates by tracing the interactions not only between the strong shocks and weak waves, but also between the strong vortex sheet/entropy wave and weak waves. The key feature of the Euler equations is that the reflection coefficient is always less than 1, when a weak wave of different family interacts with the strong vortex sheet/entropy wave or the shock wave, which is crucial to guarantee that the Glimm functional is decreasing. Then these estimates are employed to establish the convergence of the approximate solutions to a global entropy solution, close to the background solution of steady four-wave configuration.Comment: 9 figures

Using a Discrete Choice Experiment to Elicit Consumers’ WTP for Health Risk Reductions Achieved By Nanotechnology in the UK

We present research findings on consumers’ willingness to pay (WTP) for reductions in the level of foodborne health risks. The research addresses how such valuations are affected by the means of which the risk reduction is delivered and the methods of risk presentations used in choice tasks. In this case, the research has two treatments. In the first treatment, the comparison is between risk reductions achieved by an improvement in the food system in general (e.g., more stringent regulations and inspection regimes) within the slaughter and meat processing stages of the food chain, as opposed to a risk reduction achieved via innovations in food packaging using nanotechnology, which is the use of nanosensors in packaging. If there is a contamination in packaging, nanosensors reveal a colour change on the packaging material. In the second treatment, the comparison is between valuations of risk reductions in which reductions in risks are presented via absolute values and grids and absolute values together. Both comparisons are achieved via split sample Discrete Choice Experiment surveys. The difference between consumers’ valuations of foodborne risk reductions provides an implicit value for nanotechnology (i.e., WTP to avoid) and the effect of risk grids on choices people make. General results show the existence of heterogeneity in British consumers’ preferences. The effects of nanosensors and risk grids on consumers’ choices are not strong across the models. The valuations of health risk reductions show some variations across the models in both treatment groups.Discrete Choice Experiments, Nanotechnology, Nanosensors, Health Risks, Grids, UK, Health Economics and Policy,

Chronic kidney disease in Nigeria: an evaluation of the spatial accessibility to healthcare for diagnosed cases in Edo State

Chronic kidney disease (CKD) is a growing problem in Nigeria, presenting challenges to the nation’s health and economy. This study evaluates the accessibility to healthcare in Edo State of CKD patients diagnosed between 2006 and 2009. Using cost analysis techniques within a geographical information system, an estimated travel time to the hospital was used to examine the spatial accessibility of diagnosed patients to available CKD healthcare in the state. The results from the study indicated that although there was an annual rise in the number of diagnosed cases, there were no significant changes in the proportion of patients that were diagnosed at the last stage of CKD. However, there were indications that the travel time to the hospital for CKD treatment might be a contributing factor to the number of diagnosed CKD cases. This implies that the current structure for CKD management within the state might not be adequate