The World Health Organization estimates that nearly 500 million malaria tests are performed annually. While microscopy and rapid diagnostic tests (RDTs) are the main diagnostic approaches, no single method is inexpensive, rapid, and highly accurate. Two recent studies from our group have demonstrated a prototype computer vision platform that meets those needs. Here we present the results from two clinical studies on the commercially available version of this technology, the Sight Diagnostics Parasight platform, which provides malaria diagnosis, species identification, and parasite quantification. We conducted a multisite trial in Chennai, India (Apollo Hospital [n ϭ 205]), and Nairobi, Kenya (Aga Khan University Hospital [n ϭ 263]), in which we compared the device to microscopy, RDTs, and PCR. For identification of malaria, the device performed similarly well in both contexts (sensitivity of 99% and specificity of 100% at the Indian site and sensitivity of 99.3% and specificity of 98.9% at the Kenyan site, compared to PCR). For species identification, the device correctly identified 100% of samples with Plasmodium vivax and 100% of samples with Plasmodium falciparum in India and 100% of samples with P. vivax and 96.1% of samples with P. falciparum in Kenya, compared to PCR. Lastly, comparisons of the device parasite counts with those of trained microscopists produced average Pearson correlation coefficients of 0.84 at the Indian site and 0.85 at the Kenyan site.

We study various aspects of D-branes in the two families of closed N = 2 strings denoted by α and β in hep-th/0211147. We consider two types of N = 2 boundary conditions, A-type and B-type. We analyse the D-branes geometry. We compute open and closed string scattering amplitudes in the presence of the D-branes and discuss the results. We find that, except the space filling D-branes, the B-type D-branes decouple from the bulk. The A-type D-branes exhibit inconsistency. We construct the D-branes effective worldvolume theories. They are given by a dimensional reduction of self-dual Yang-Mills theory in four dimensions. We construct the D-branes gravity backgrounds. Finally, we discuss possible N = 2 open/closed string dualities.1 Here I, J = 1, ..., 4 denote the indices of the target space in a real basis. The metric is given by η IJ = diag(−1, −1, +1, +1). J L IJ is a Kähler form related to the complex structure J K J by J IJ = η IK J K J , and the index L refers to the left sector. Similarly, we have the SCA generators in the right sector with a complex structure J R . The N = 2 string denoted by β-string in [3] is defined by having the same complex structure in the left and right sectors J L = J R . The N = 2 string denoted as α-string in [3] has different (inequivalent) complex structures in the left and right sectors.

N = 2 closed strings have been recently divided in hep-th/0211147 to two T-dual families denoted by α and β. In (2, 2) signature both families have one scalar in the spectrum. The scalar in the β-string is known to be a deformation of the target space Kähler potential and the dynamics is that of self-dual gravity. In this paper we compute the effective action of the scalar in the α-string. The scalar is a deformation of a potential that determines the metric, torsion and dilaton. The scalar is free and the dynamics is that of a self-dual curvature with torsion. The result is in agreement with a σ-model computation of Hull.1 Here I, J = 1, ..., 4 denote the indices of the target space in a real basis. The metric is given by η IJ = diag(−1, −1, +1, +1). J L IJ is a Kähler form related to the complex structure J K J by J IJ = η IK J K J , and the index L refers to the left sector. 1 Similarly, we have the SCA generators in the right sector with a complex structure J R . The (conventional) N = 2 string denoted by β-string in [3] is defined by having the same complex structure in the left and right sectors J L = J R . On the other hand, N = 2 string denoted by α-string in [3] has different complex structures in the left and right sectors 2 . In fact the β-and α-strings define two families of N = 2 strings related by T-duality [3].

Telomeres are DNA repeats protecting chromosomal ends which shorten with each cell division, eventually leading to cessation of cell growth. We present a population mixture model that predicts an exponential decrease in telomere length with time. We analytically solve the dynamics of the telomere length distribution. The model provides an excellent fit to available telomere data and accounts for the previously unexplained observation of telomere elongation following stress and bone marrow transplantation, thereby providing insight into the nature of the telomere clock.

We study closed N = 2 strings on orbifolds of the form T 4 /Z 2 and C 2 /Z 2 . We compute the torus partition function and prove its modular invariance. We analyze the BRST cohomology of the theory, construct the vertex operators, and compute three and four point amplitudes of twisted and untwisted states. We introduce a background of D-branes, and compute twist states correlators.