The positive semidefinite (psd) rank of a polytope is the smallest k for which the cone of k × k real symmetric psd matrices admits an affine slice that projects onto the polytope. In this paper we show that the psd rank of a polytope is at least the dimension of the polytope plus one, and we characterize those polytopes whose psd rank equals this lower bound.

Gradient-type iterative methods for solving Hermitian eigenvalue problems can be accelerated by using preconditioning and deflation techniques. A preconditioned steepest descent iteration with implicit (PSD-id) is one of such methods. The convergence behavior the PSD-id recently investigated based on pioneering work Samokish method (PSD). resulting non-asymptotic estimates indicate a superlinea...

BACKGROUND The pathophysiology of poststroke depression (PSD) remains elusive because of its proposed multifactorial nature. Accumulating evidence suggests that brain-derived neurotrophic factor (BDNF) plays a key role in the pathophysiology of depression and PSD. And the cerebellar dysfunction may be important in the etiology of depression; it is not clear whether it also has a major effect on...

The membrane-associated guanylate kinase PSD-95 scaffolds N-methyl-d-aspartate receptors to cytoplasmic signaling molecules, and associates with other glutamate receptors at central synapses. However, regulation of PSD-95 in vivo is poorly understood. We provide evidence of an activity-dependent redistribution of PSD-95 to dendrites in central visual neurons that is tied to eye opening. Six hou...

The cellular mechanisms involved in the formation of the glutamatergic postsynaptic density (PSD) are mainly unknown. Previous studies have indicated that PSD assembly may occur in situ by a gradual recruitment of postsynaptic molecules, whereas others have suggested that the PSD may be assembled from modular transport packets assembled elsewhere. Here we used cultured hippocampal neurons and l...

The 2-dimensional Power Spectral Density (PSD) can be used to characterize the midand the high-spatial frequency components of the surface height errors of an optical surface. We found it necessary to have a complete, easy-to-use approach for specifying and evaluating the PSD characteristics of large optical surfaces, an approach that allows one to specify the surface quality of a large optical...

The aim of this study was to quantify the morphological changes in the arterial wall resulting from poststenotic dilatation (PSD). PSD was produced by placing a split nylon ring around the thoracic aorta of the rabbits at a level of T6-7 during a sterile thoracotomy done under pentobarbital anesthesia. After period of PSD ranging from 1-51 months these rabbits were anesthetized, as were the con...

NMDA receptors interact directly with postsynaptic density-95 (PSD-95), a scaffold protein that organizes a cytoskeletal- signaling complex at the postsynaptic membrane. The molecular mechanism by which the PSD-95-based protein complex is trafficked to the postsynaptic site is unknown but presumably involves specific motor proteins. Here we demonstrate a direct interaction between the PSD-95-as...

The different expressions of NR2 and synaptic-associated proteins have been studied by protein and mRNA level with immunoblotting, in situ hybridization, or immunogold analysis. But the relationship between NR2 subunits and PSD-95 family proteins is still controversial. In this study, we used immunofluorescent staining to assess NR2B and PSD-95 expressions and the relationship between them in C...

Acid-sensing ion channel 3 (ASIC3) is a H(+)-gated cation channel primarily found in sensory neurons, where it may function as a pH sensor in response to metabolic disturbances or painful conditions. We previously found that ASIC3 interacts with the postsynaptic density protein PSD-95 through its COOH terminus, which leads to a decrease in ASIC3 cell surface expression and H(+)-gated current. P...