Homospermidine synthase (HSS) catalyzes the synthesis of the polyamine homospermidine from 2 mol putrescine in an NAD(+)-dependent reaction. In this study, the enzyme was purified from anaerobically grown cultures of the photosynthetic bacterium Rhodopseudomonas viridis to electrophoretic homogeneity using a three-step procedure. The enzyme was shown to be a homodimer of 52-kDa subunits. Six en...

Randomized sampling has recently been proven a highly efficient technique for computing approximate factorizations of matrices that have low numerical rank. This paper describes an extension of such techniques to a wider class of matrices that are not themselves rank-deficient, but have off-diagonal blocks that are; specifically, the class of so called Hierarchically Semi-Separable (HSS) matric...

Regulation of TNF gene expression is cell type- and stimulus-specific. We have previously identified highly conserved noncoding regulatory elements within DNase I-hypersensitive sites (HSS) located 9 kb upstream (HSS-9) and 3 kb downstream (HSS+3) of the TNF gene, which play an important role in the transcriptional regulation of TNF in T cells. They act as enhancers and interact with the TNF pr...

The main result of the present paper is a method to transform a matrix or operator which has a hierarchical semi-separable (HSS) representation into a URV (Moore-Penrose) representation in which the operators U and V represent collections of efficient orthogonal transformations and the block upper matrix R still has the HSS form. The paper starts with an introduction to HSS-forms and a survey o...

De novo prediction of protein folding is an open scientific challenge. Many folding models and force fields have been developed, yet all face difficulties converging to native conformations. Hydrophobicity scales (HSs) play a crucial role in such simulations as they define the energetic interactions between protein residues, thus determining the energetically favorable conformation. While many ...

PURPOSE To evaluate the effect of Haishengsu (HSS), a protein extract from Tegillarca granosa, on multidrug-resistance genes mdr1, BCR/ABL and sorcin in transplanted tumors. MATERIAL/METHODS Mice were inoculated subcutaneously with a drug resistant leukemia cell line K562/ADM. Tumor-bearing animals were divided into control, adriamycin, HSS and combination therapy (adriamycin plus HSS) groups...

OBJECTIVE To evaluate Brazil's public health surveillance system (HSS), identifying its core capacities, shortcomings, and limitations in dealing with public health emergencies, within the context of the International Health Regulations (IHR 2005). METHODS In 2008-2009 an evaluative cross-sectional study was conducted using semistructured questionnaires administered to key informants (municip...

Humic substances (HSs) are ubiquitous in various aquatic systems and play important roles in many geochemical processes. There is increasing evidence of the presence of HSs in deep groundwater; nevertheless, their ion binding properties are largely unknown. In this study we investigated the physicochemical and ion-binding properties of humic and fulvic acids extracted from deep sedimentary grou...

While Src plays crucial roles in shear stress-induced cellular processes, little is known on the spatiotemporal pattern of high shear stress (HSS)-induced Src activation. HSS (65 dyn/cm(2)) was applied on bovine aortic endothelial cells to visualize the dynamic Src activation at subcellular levels utilizing a membrane-targeted Src biosensor (Kras-Src) based on fluorescence resonance energy tran...