Hedging with interest rate caps compared with a policy of maintaining a balanced portfolio of loans (PLA) and averaging the borrowing costs

This paper compares two different strategies for managing interest rate exposure. One involves maintaining a borrowing portfolio using short and long term debt lines in order to maintain an average borrowing cost. The second involves using interest rate caps to manage exposure to interest rate risk. The two strategies are compared using a set of daily quarterly rates from three months out to 10 years (120 months) of BBSW zero rates, par rates and forward rates from June 2000 to September 2006. The data set of implied volatilities (Appendix I used for interest cap quoting and pricing) consists of volatilities for 1, 2, 3, 4, 5, 7 and 10 year maturities; the data set is made up of daily closing mid-quotes for the period. We examine whether interest rate caps would be a better alternative for minimising interest rate risk as compared to a structure that combines a portfolio of rolling short-term debt with one of rolling long-term debt lines. Using principal component analysis (PCA) we explore the behaviour of, and the number of factors driving volatilities. As caps are quoted in terms of implied volatilities, and we know BlackÃŒs (1976) model is very sensitive to changes in these volatilities. We use PCA to examine the factors driving cap price volatilities. We explore the best way of using caps to manage interest rate risk. This should help us understand what factors affect cap prices and how many factors might be used in the interest rate models used to price interest rate derivatives such as caps and floors. We use Sharpe ratios to assess the relative borrowing costs of different strategies in relation to the volatility of their outcomes. We examine whether interest rate caps would be a more efficient method for minimising interest rate risk as compared to the a portfolio of loans.Hedging with interest rate caps, Vegas, Sharpe ratios, Principle components analysis

A neuronal network model of interictal and recurrent ictal activity

We propose a neuronal network model which undergoes a saddle-node bifurcation on an invariant circle as the mechanism of the transition from the interictal to the ictal (seizure) state. In the vicinity of this transition, the model captures important dynamical features of both interictal and ictal states. We study the nature of interictal spikes and early warnings of the transition predicted by this model. We further demonstrate that recurrent seizures emerge due to the interaction between two networks.Comment: 9 pages, 7 figure

Reducing the sodium content of high-salt foods: Effect on cardiovascular disease in South Africa

Background. Average salt intake in South African (SA) adults, 8.1 g/day, is higher than the 4 - 6 g/day recommended by the World Health Organization. Much salt consumption arises from non-discretionary intake (the highest proportion from bread, with contributions from margarine, soup mixes and gravies). This contributes to an increasing burden of hypertension and cardiovascular disease (CVD).Objectives. To provide SA-specific information on the number of fatal CVD events (stroke, ischaemic heart disease and hypertensive heart disease) and non-fatal strokes that would be prevented each year following a reduction in the sodium content of bread, soup mix, seasoning and margarine.Methods. Based on the potential sodium reduction in selected products, we calculated the expected change in population-level systolic blood pressure (SBP) and mortality due to CVD and stroke.Results. Proposed reductions would decrease the average salt intake by 0.85 g/person/day. This would result in 7 400 fewer CVD deaths and 4 300 less non-fatal strokes per year compared with 2008. Cost savings of up to R300 million would also occur.Conclusion. Population-wide strategies have great potential to achieve public health gains as they do not rely on individual behaviour or a well-functioning health system. This is the first study to show the potential effect of a salt reduction policy on health in SA

Robusticity of Bovidae skeletal elements from southern Africa and their potential in species identification

Faunal analysis is crucial in the investigation of the complexity of caves and archaeological sites. Osteological measurements are often used for human remains as a means of identification, and can also be used for animal bones. Sometimes measurements constitute the only method of accurate identification and can be used to distinguish between similar species.The aim of this study was to assess measurements reflecting robusticity in bovids, in order to establish whether this could be used for identification of unknown animal bones, or at least indicate bovid size class. In total, 846 femora, tibiae, and metatarsals of bovids in the various size classes classified as proposed by Brain (1974) were measured.The maximum long bone length and smallest shaft circumference of modern southern African specimens were used. In order to assess the robusticity of the bones, a robusticity index was calculated for each bone.The calculated indices for the three hind limb bones showed that there is a large degree of overlap between most of the species on all three bones.There are, however, a few species that could be identified purely on their index values if the Bovid size class were known. Buffalo (Syncerus caffer) showed almost no overlap with any other species and was the most robust in all three long bones. Sitatunga (Tragelaphus spekeii) femur and tibia were the least robust, whereas springbok (Antidorcas marsupialis) had the most gracile metatarsal.Bov classes I and II were overall less robust than Bov classes III and IV in all three bones. With further studies and a larger specimen database, specific values may prove to be important in identifying the different Bovid size classes and possibly give some insight into lifestyle adaptations in mammals

Carcinoid heart disease: Two clinical cases and a review

We present two cases of metastatic carcinoid tumours, complicated by carcinoid syndrome and by cardiac valve involvement, a well-known, but infrequent, complication. Carcinoid tumours are generally more indolent than other cancers and may have a long asymptomatic phase. The symptoms of carcinoid syndrome generally manifest only once metastases to the liver have occurred. Cardiac involvement occurs in up to 50% of patients, and heralds a poor prognosis. However, a multidisciplinary team approach has improved the prognosis and quality of life for patients with carcinoid heart disease. Therapy includes somatostatin analogues and treatment for heart failure, removal of primary or metastatic tumour deposits, valve replacement in the presence of valvular involvement, and radioisotopes therapy

Postnatal β2 adrenergic treatment improves insulin sensitivity in lambs with IUGR but not persistent defects in pancreatic islets or skeletal muscle

Placental insufficiency causes intrauterine growth restriction (IUGR) and disturbances in glucose homeostasis with associated β adrenergic receptor (ADRβ) desensitization. Our objectives were to measure insulin-sensitive glucose metabolism in neonatal lambs with IUGR and to determine whether daily treatment with ADRβ2 agonist and ADRβ1/β3 antagonists for 1 month normalizes their glucose metabolism. Growth, glucose-stimulated insulin secretion (GSIS) and glucose utilization rates (GURs) were measured in control lambs, IUGR lambs and IUGR lambs treated with adrenergic receptor modifiers: clenbuterol atenolol and SR59230A (IUGR-AR). In IUGR lambs, islet insulin content and GSIS were less than in controls; however, insulin sensitivity and whole-bodyGUR were not different from controls.Of importance, ADRβ2 stimulation with β1/β3 inhibition increases both insulin sensitivity and whole-body glucose utilization in IUGR lambs. In IUGR and IUGR-AR lambs, hindlimb GURs were greater but fractional glucose oxidation rates and ex vivo skeletal muscle glucose oxidation rates were lower than controls. Glucose transporter 4 (GLUT4) was lower in IUGR and IUGR-AR skeletal muscle than in controls but GLUT1 was greater in IUGR-AR. ADRβ2, insulin receptor, glycogen content and citrate synthase activity were similar among groups. In IUGR and IUGR-AR lambs heart rates were greater, which was independent of cardiac ADRβ1 activation. We conclude that targeted ADRβ2 stimulation improved whole-body insulin sensitivity but minimally affected defects in GSIS and skeletal muscle glucose oxidation. We show that risk factors for developing diabetes are independent of postnatal catch-up growth in IUGR lambs as early as 1 month of age and are inherent to the islets and myocytes

South Africa's salt reduction strategy: Are we on track, and what lies ahead?

On 2 September 2016, 25 local and international participants from various sectors met in Cape Town to take stock of South Africa (SA)’s progress in salt reduction and develop a roadmap for action. SA is centre stage on salt reduction globally, being the first country to mandate salt reduction across a wide range of processed foods. Excessive salt intake contributed by processed foods and discretionary sources motivated SA to implement a public awareness campaign in parallel with legislation to reduce salt intake to the World Health Organization target of 5 g per day. Five priority areas were identified for continued action on salt reduction, including obtaining research funds for continued monitoring and compliance of salt reduction targets. Determining the contribution of foods eaten out of home to total salt intake and implementing strategies to address this sector were also highlighted as key actions. Lastly, implementing the next stage of the Salt Watch awareness campaign to change

Entropies of the EEG: The effects of general anaesthesia

The aim of this paper was to compare the performance of different entropy estimators when applied to EEG data taken from patients during routine induction of general anesthesia. The question then arose as to how and why different EEG patterns could affect the different estimators. Therefore we also compared how the different entropy estimators responded to artificially generated signals with predetermined, known, characteristics. This was done by applying the entropy algorithms to pseudoEEG data: (1) computer-generated using a second-order autoregressive (AR2) model, (2) computer-generated white noise added to step signals simulating blink and eyemovement artifacts and, (3) seeing the effect of exogenous (computer-generated) sine-wave oscillations added to the actual clinically-derived EEG data set from patients undergoing induction of anesthesia