Hyperbolic subdiffusive impedance

We use the hyperbolic subdiffusion equation with fractional time derivatives (the generalized Cattaneo equation) to study the transport process of electrolytes in media where subdiffusion occurs. In this model the flux is delayed in a non-zero time with respect to the concentration gradient. In particular, we obtain the formula of electrochemical subdiffusive impedance of a spatially limited sample in the limit of large and of small pulsation of the electric field. The boundary condition at the external wall of the sample are taken in the general form as a linear combination of subdiffusive flux and concentration of the transported particles. We also discuss the influence of the equation parameters (the subdiffusion parameter and the delay time) on the Nyquist impedance plots.Comment: 10 pages, 5 figure

Time evolution of the reaction front in a subdiffusive system

Using the quasistatic approximation, we show that in a subdiffusion--reaction system the reaction front $x_{f}$ evolves in time according to the formula $x_{f} \sim t^{\alpha/2}$, with $\alpha$ being the subdiffusion parameter. The result is derived for the system where the subdiffusion coefficients of reactants differ from each other. It includes the case of one static reactant. As an application of our results, we compare the time evolution of reaction front extracted from experimental data with the theoretical formula and we find that the transport process of organic acid particles in the tooth enamel is subdiffusive.Comment: 18 pages, 3 figure

Search for a Correlation Between Radio Giant Pulses and VHE Photons of the Crab Pulsar

The Crab pulsar is a unique source of pulsar radio emission. Its regular pulse structure is visible over the entire electromagnetic spectrum from radio to GeV ranges. Among the regular pulses, radio giant pulses (GPs) are known as a special form of pulsar radio emission. Although the Crab pulsar was discovered by its GPs, their origin and emission mechanisms are currently not understood. Within the framework of this report we give a review on radio GPs and present a new idea on how to examine the characteristics of this as yet not understood kind of pulsar emission

Cost-effectiveness of a complex intervention in general practice to increase uptake of long-acting reversible contraceptives in Australia.

Objective The aim of this study was to evaluate the cost-effectiveness of the Australian Contraceptive ChOice pRoject (ACCORd) intervention. Methods An economic evaluation compared the costs and outcomes of the ACCORd intervention with usual care (UC). Data from the ACCORd trial were used to estimate costs and efficacy in terms of contraceptive uptake and quality of life. Rates of contraceptive failure and pregnancy were sourced from the literature. Using a Markov model, within-trial results were extrapolated over 10 years and subjected to univariate sensitivity analyses. Model outputs were expressed as the cost per quality-adjusted life years (QALY) gained and cost per unintended pregnancy resulting in birth (UPB) avoided. Results Over 10 years, compared with UC, initiating contraception through the ACCORd intervention resulted in 0.02 fewer UPB and higher total costs (A$2505 vs A$1179) per woman. The incremental cost-effectiveness of the ACCORd intervention versus UC was A$1172 per QALY gained and A$7385 per UPB averted. If the start-up cost of the ACCORd intervention was removed, the incremental cost-effectiveness ratio was A$81 per QALY gained and A$511 per UPB averted. The results were most sensitive to the probability of contraceptive failure, the probability of pregnancy-related healthcare service utilisation or the inclusion of the costs of implementing the ACCORd intervention. Conclusions From a health system perspective, if implemented appropriately in terms of uptake and reach, and assuming an implicit willingness to pay threshold of A$50 000 the ACCORd intervention is cost-effective. What is known about the topic? The uptake of long-active reversible contraceptives (LARC) in Australia is low. The ACCORd trial assessed the efficacy of providing structured training to general practitioners (GPs) on LARC counselling, together with access to rapid referral to insertion clinics. What does this paper add? This study is the first to assess the cost-effectiveness of a complex intervention in the general practice setting aimed at increasing the uptake of LARC in Australia. What are the implications for practitioners? The results show that implementing a complex intervention in general practice involving GP education and the availability of rapid referral to LARC insertion clinics is a cost-effective approach to increase LARC use and its attending efficacy. If the majority of Australian GPs were able to deliver effectiveness-based contraceptive counselling and either insert LARC or use a rapid referral process to a LARC insertion clinic, the additional cost associated with the purchase of LARC products and their insertion would be offset by reductions to health system costs as a result of fewer UPB and abortions. Moreover, the benefits to women's physical and psychological health of avoiding such events is substantial