21 research outputs found
Exact controllability of non-Lipschitz semilinear systems
We present sufficient conditions for exact controllability of a semilinear infinite-dimensional dynamical system. The system mild solution is formed by a noncompact semigroup and a nonlinear disturbance that does not need to be Lipschitz continuous. Our main result is based on a fixed point-type application of the Schmidt existence theorem and illustrated by a nonlinear transport partial differential equation
An approach to developing a prediction model of fertility intent among HIV-positive women and men in Cape Town, South Africa: a case study
As a ‘case-study’ to demonstrate an approach to establishing a fertility-intent prediction model, we used data collected from recently diagnosed HIV-positive women (N = 69) and men (N = 55) who reported inconsistent condom use and were enrolled in a sexual and reproductive health intervention in public sector HIV care clinics in Cape Town, South Africa. Three theoretically-driven prediction models showed reasonable sensitivity (0.70–1.00), specificity (0.66–0.94), and area under the receiver operating characteristic curve (0.79–0.89) for predicting fertility intent at the 6-month visit. A k-fold cross-validation approach was employed to reduce bias due to over-fitting of data in estimating sensitivity, specificity, and area under the curve. We discuss how the methods presented might be used in future studies to develop a clinical screening tool to identify HIV-positive individuals likely to have future fertility intent and who could therefore benefit from sexual and reproductive health counselling around fertility options
Neurocysticesosis in an orthodox jewish-community in New-York-city
Background and Methods. From June 1990 through July 1991, intracerebral infection with the larval stage of the pork tapeworm Taenia solium was diagnosed in four unrelated persons in an Orthodox Jewish community in New York City. None of the patients had eaten pork, and only one had traveled to a country in which T solium infection was endemic. We investigated this outbreak, screened serum samples from family members and household contacts for antibodies to cysticercosis, and examined stool specimens from household employees for eggs of taenia species.Results. The four patients had recurrent seizures and brain lesions that were radiologically consistent with the presence of cysticerci. The diagnosis was confirmed in two patients by a brain biopsy, and in two by immunoblot assays for cysticercus antibodies. Of 17 immediate family members screened serologically, 7 from two families had cysticercus antibodies. Magnetic resonance imaging of the brain showed cystic lesions in two of the seropositive family members, one of whom had had a seizure. Examinations of six domestic employees from all four households revealed an active infection with taenia species in one and a positive serologic test in another. Since these women had recently emigrated from Latin American countries where T. solium infection is endemic, they were the most likely sources of infection in the members of these households.Conclusions. A diagnosis of neurocysticercosis should be considered in patients with seizures and radiologic evidence of cystic brain lesions, even in those who do not eat pork and who have not traveled to a country in which T. solium infection is endemic. Recent emigrants from countries in which T. solium infection is endemic should be screened for tapeworm infection in their stools before they are employed as housekeepers or food handlers