We demonstrate experimentally an optical process in which the spin angular momentum carried by a circularly polarized light beam is converted into orbital angular momentum, leading to the generation of helical modes with a wave-front helicity controlled by the input polarization. This phenomenon requires the interaction of light with matter that is both optically inhomogeneous and anisotropic. ...

BACKGROUND Disclosure of HIV serostatus can have significant benefits for people living with HIV/AIDS. However, there is limited data on whether partner disclosure influences ART treatment response. METHODS We conducted a retrospective cohort study of newly diagnosed, ART-naïve HIV-infected adults (>18 years) who enrolled at the Coptic Hope Center in Nairobi, Kenya between January 1st 2009 an...

The natural history and optimal treatment for idiopathic toe walking are unknown. The literature is full of poorly documented treatment regimens with few even medium term follow up studies. The senior author reports his nearly 30 year approach to this disorder and his failed attempt to perform a follow up study of his particular treatment regimen. We conclude with our considered interpretation ...

Studies from Kenya have reported rapid clinical disease progression among HIV-infected professional sex workers. The reasons for this rapid decline are unknown. To better understand factors influencing the course of disease, HIV-1 disease progression was explored in terms of declines in CD4 counts. Two samples from Nairobi, Kenya, were studied, one from a cohort of female sex workers and anothe...

As a new slant on T lymphocyte repertoire selection, we have examined batteries of TCR sequences in thymi from transgenic mice engineered to exhibit limited, focussed TCR diversity. We have tracked the fate of differentiating thymocytes expressing a set of particular TCR through the positive selection process. Subtly different TCR sequences can promote different maturation pathways and commitme...

The development of cellular immune responses in primary human immunodeficiency virus type-1 (HIV-1) infection is accompanied by a dramatic decrease in plasma viremia and resolution of the acute clinical syndrome. The full nature of the immunological response and its consequences on HIV pathogenesis is still largely a mystery, but significant progress has been achieved in the characterization of...

Positive Darwinian selection at the molecular level is often studied by comparing the number of synonymous nucleotide substitutions per synonymous site (d,) and the number of nonsynonymous substitutions per nonsynonymous site (dN) between homologous gene sequences, and a t-test with an infinite number of degrees of freedom is usually used for determining the statistical significance of the diff...

Clinical trials are the standard for identifying new drugs for the treatment of disease, but results are dependent on patient compliance. The success of treatments for HIV disease in particular may be judged in part by their effect on immunologic, virologic, or clinical measures collected on patients at regular predefined intervals. If patients drop out of a trial before study completion, the a...