Pediatric DXA: clinical applications

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation

Estimating A Smooth Term Structure of Interest Rates

This paper extends the literature of the term structure estimation with splines. We fit the term struc-ture of interest rates with a smoothing spline method that uses a different smoothing norm and locates the knot points by the size of the fitting errors. The method is applied to the Finnish fixed income market and compared to the usual smoothing spline methods and to the equally spaced knot loca-tions. The results show that the new method where the spline is placed on the log of the discount function and the knots are located freely outperforms the other methods