6,211 research outputs found
Participation in Self-Collection of Maternal and Infant DNA in a Case-Control Study on Clubfoot
National Institute of Child Health and Human Development (HD051804
Symptomatic central nervous system tuberculoma, a case report in the United States and literature review
Intracranial tuberculoma is one of the rare central nervous system manifestations of Mycobacterium tuberculosis (MTB), seen in only 1% of tuberculosis patients. It can manifest as single or multiple lesions, most commonly located in the frontal and parietal lobes. Clinical features are similar to any space-occupying lesion in the brain and can present in the absence of MTB symptoms in other parts of the body. In this article, a 69-year-old immunocompetent man, with history of treated latent tuberculosis infection (LTBI) was reported. He presented with multiple joint arthralgias, weight loss, odd behavior, forgetfulness, intermittent fevers and syncope. Brain imaging revealed numerous enhancing intra-parenchymal lesions in cerebral and cerebellar hemispheres. Patient was successfully treated with anti-tuberculosis medications and corticosteroids, with clinical improvement on future follow ups. High clinical suspicion for tuberculoma as a differential diagnosis of any brain lesion, even in immunocompetent patients in low MTB prevalence countries, can result in early diagnosis and successful clinical outcomes
Compressed Sensing Using Binary Matrices of Nearly Optimal Dimensions
In this paper, we study the problem of compressed sensing using binary
measurement matrices and -norm minimization (basis pursuit) as the
recovery algorithm. We derive new upper and lower bounds on the number of
measurements to achieve robust sparse recovery with binary matrices. We
establish sufficient conditions for a column-regular binary matrix to satisfy
the robust null space property (RNSP) and show that the associated sufficient
conditions % sparsity bounds for robust sparse recovery obtained using the RNSP
are better by a factor of compared to the
sufficient conditions obtained using the restricted isometry property (RIP).
Next we derive universal \textit{lower} bounds on the number of measurements
that any binary matrix needs to have in order to satisfy the weaker sufficient
condition based on the RNSP and show that bipartite graphs of girth six are
optimal. Then we display two classes of binary matrices, namely parity check
matrices of array codes and Euler squares, which have girth six and are nearly
optimal in the sense of almost satisfying the lower bound. In principle,
randomly generated Gaussian measurement matrices are "order-optimal". So we
compare the phase transition behavior of the basis pursuit formulation using
binary array codes and Gaussian matrices and show that (i) there is essentially
no difference between the phase transition boundaries in the two cases and (ii)
the CPU time of basis pursuit with binary matrices is hundreds of times faster
than with Gaussian matrices and the storage requirements are less. Therefore it
is suggested that binary matrices are a viable alternative to Gaussian matrices
for compressed sensing using basis pursuit. \end{abstract}Comment: 28 pages, 3 figures, 5 table
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