Melasma is a common acquired hypermelanosis of the skin that has been associated with several etiologic factors including ultraviolet light exposure, pregnancy, and oral contraceptives (OCPs) (1). Forty-one percent of women surveyed in one study had onset of melasma after pregnancy, and 25% after starting an OCP (2). Women who develop melasma during pregnancy may be more susceptible to developi...

In this article, we discuss fractional order optimal control problems (FOCPs) and their solutions by means of rational approximation. The methodology developed here allows us to solve a very large class of FOCPs (linear/nonlinear, time-invariant/time-variant, SISO/MIMO, state/input constrained, free terminal conditions etc.) by converting them into a general, rational form of optimal control pr...

A well–known problem in indirect optimal control is to find a suitable initial guess for the adjoint states which is sufficiently close to the optimal solution. This paper presents a new homotopy approach to overcome this problem by deriving an auxiliary optimal control problem (OCP) for which the adjoint states are simply zero. A continuation method is employed to smoothly reach the original O...

BACKGROUND Cerebral venous sinus thrombosis is a rare and potentially life-threatening neurologic manifestation of antiphospholipid syndrome. Oral contraceptive pills (OCP) may increase the risk of vascular events, even in people without family history of venous thrombosis. CASE PRESENTATION A 31-year-old woman with four weeks of constant headache and history of taking OCP for one year has be...

Calcium phosphate (Ca-P) coatings on zirconia bone implants have a great potential to improve the osseointegration of already existing ceramic implants, owing to their bone-bonding ability and high osteoconductive characteristics. In our study, we have prepared three different kinds of Ca-P coatings, namely the octacalcium phosphate (OCP), hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP)...

Mental variables are central to symbolic accounts of cognition. Conversely, according to the pattern associator hypothesis, variables are obsolete. We examine the representation of variables by investigating the Obligatory Contour Principle (OCP, McCarthy, 1986) in Hebrew. The OCP constrains gemination in Hebrew roots. Gemination is well formed at the root's end (e.g., SMM), but not in its begi...

Zooplankton contamination represents a major constraint in large-scale microalgal cultivation systems. While zooplankton cannot be avoided, their development can controlled by regulating the dilution rate. However, it is not straightforward to find best control strategy for Low rates (or long retention times) favor grazer and high avoid establishment at risk of reducing productivity. Furthermor...

Initially planned for a 20 year life time, the Onchocerciasis Control Programme in West Africa (OCP) will have finally continued its activities for nearly three decades (vector control alone from 1975 to 1989, then vector control and/or therapeutic treatment until 2002). Although onchocerciasis is no longer a problem of public health importance nor an obstacle to socio-economic development in t...