Cerebrospinal fluid (CSF) S-adenosylmethionine (SAM) levels were significantly lower in severely depressed patients than in a neurological control group. The administration of SAM either intravenously or orally is associated with a significant rise of CSF SAM, indicating that it crosses the blood-brain barrier in humans. These observations provide a rational basis for the antidepressant effect ...

This paper presents the design and evaluation of a sequential access memory (SAM) that provides low power and high performance by replacing address decoders with special locally-communicating sequencers. A test chip containing one 16x16-b SAM and one 64x16-b SAM (consisting of four 16x16-b banks) has been designed, fabricated, and evaluated using a 0.25-μm CMOS process. With a clock frequency o...

Shepard has supposed that the mind is stocked with innate knowledge of the world and that this knowledge figures prominently in the way we see the world. According to him, this internal knowledge is the legacy of a process of internalization; a process of natural selection over the evolutionary history of the species. Shepard has developed his proposal most fully in his analysis of the relation...

The context in which a stimulus occurs can influence its perception. We study contextual effects in audition using the tritone paradox, where a pair of complex (Shepard) tones separated by half an octave can be perceived as ascending or descending. While ambiguous in isolation, they are heard with a clear upward or downward change in pitch, when preceded by spectrally matched biasing sequences....

Recent studies indicate that in patients with muscular subaortic stenosis at rest, left ventricular outflow tract obstruction is associated with severe systolic anterior motion (SAM) of the anterior mitral leaflet and prolonged SAM-septal contact. We correlated the temporal relationships between echocardiographic and hemodynamic events in 18 patients with muscular subaortic stenosis (gradient o...

SAM (sterile alpha motif) domains are protein-protein interaction modules found in a large number of regulatory proteins. Byr2 and Ste4 are two SAM domain-containing proteins in the mating pheromone response pathway of the fission yeast, Schizosaccharomyces pombe. Byr2 is a mitogen-activated protein kinase kinase kinase that is regulated by Ste4. Tu et al. (Tu, H., Barr, M., Dong, D. L., and Wi...

Patient classification through feature selection (FS) based on gene expression data (GED) has already become popular to the research communities. T-test is the well-known statistical FS method in GED analysis. However, it produces higher false positives and lower accuracies for small sample sizes or in presence of outliers. To get rid from the shortcomings of t-test with small sample sizes, SAM...

All organisms require S-adenosylmethionine (SAM) as a methyl group donor and cofactor for various biologically important processes. However, certain obligate intracellular parasitic bacteria and also the amoeba symbiont Amoebophilus asiaticus have lost the capacity to synthesize this cofactor and hence rely on its uptake from host cells. Genome analyses revealed that A. asiaticus encodes a puta...

'Radical SAM' enzymes generate catalytic radicals by combining a 4Fe-4S cluster and S-adenosylmethionine (SAM) in close proximity. We present the first crystal structure of a Radical SAM enzyme, that of HemN, the Escherichia coli oxygen-independent coproporphyrinogen III oxidase, at 2.07 A resolution. HemN catalyzes the essential conversion of coproporphyrinogen III to protoporphyrinogen IX dur...

S-Adenosylmethionine (SAM) is formed exclusively in the cytosol but plays a major role in plastids; SAM can either act as a methyl donor for the biogenesis of small molecules such as prenyllipids and macromolecules or as a regulator of the synthesis of aspartate-derived amino acids. Because the biosynthesis of SAM is restricted to the cytosol, plastids require a SAM importer. However, this tran...