Unconventional Charge Density Wave Arising from Electron–Phonon Interaction

We report of a theoretical study on quasi-one dimensional unconventional charge density wave (UCDW) driven by electron–phonon interaction. Within mean field theory, we find that the wavevector dependence of the coupling leads to a momentum dependent single particle gap on the Fermi surface. The presence of small energy single particle excitations around the gap nodes significantly changes the optical conductivity compared to the conventional CDW result. In addition to that, the collective phase excitation arising from fluctuation of the order parameter leads to further qualitative changes of the conductivity and results in an effective mass that is nonmonotonic in temperature.      

Neuropsychological and psychosocial effects of the FMR-1 full mutation: Case report of monozygotic twins discordant for the fragile X syndrome.

An extensive evaluation was conducted with 16-yr-old monozygotic twins concordant for the fragile X full mutation but discordant for mental retardation. The clearly affected twin had an IQ score of 47; 77% of her neuropsychological z scores were at least 2 SDs below average. Her sister had an IQ score of 105 and average neuropsychological performance. However, each girl demonstrated relative verbal strengths and visual-spatial weaknesses. Their parents rated each girl as having significant problems with attention, conduct, anxiety-withdrawal, and hyperactivity. The girls did not rate themselves as having significant anxiety. These findings are consistent with group data on females with fragile X and demonstrate the wide range of effects associated with the fragile X full mutation. This case report implicates the importance of a psychosocial phenotype of fragile X independent of cognitive ability level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bioavailability of phenytoin acid and phenytoin sodium with enteral feedings

In the absence of E1B, the 289-amino acid product of human adenovirus type 5 13S E1A induces p53-independent apoptosis by a mechanism that requires viral E4 gene products (Marcellus, R.C., J.C. Teodoro, T. Wu, D.E. Brough, G. Ketner, G.C. Shore, and P.E. Branton. 1996. J. Virol. 70:6207-6215) and involves a mechanism that includes activation of caspases (Boulakia, C.A., G. Chen, F.W. Ng, J. G. Teodoro, P.E. Branton, D.W. Nicholson, G.G. Poirier, and G.C. Shore. 1996. Oncogene. 12:529-535). Here, we show that one of the E4 products, E4orf4, is highly toxic upon expression in rodent cells regardless of the p53 status, and that this cytotoxicity is significantly overcome by coexpression with either Bcl-2 or Bcl-XL. Conditional expression of E4orf4 induces a cell death process that is characterized by apoptotic hallmark features, such as externalization of phosphatidylserine, loss of mitochondrial membrane potential, cytoplasmic vacuolation, condensation of chromatin, and internucleosomal DNA degradation. However, the wide-spectrum inhibitor of caspases, tetrapeptide zVAD-fmk, does not affect any of these apoptogenic manifestations, and does not alter the kinetics of E4orf4-induced cell death. Moreover, E4orf4 expression does not result in activation of the downstream effector caspase common to most apoptosis-inducing events, caspase-3 (CPP32). We conclude, therefore, that in the absence of E1A, E4orf4 is sufficient by itself to trigger a p53-independent apoptosis pathway that may operate independently of the known zVAD-inhibitable caspases, and that may involve an as yet uncharacterized mechanism.     

Degradation of NiCr/CuNiMn/NiCr films on alumina substrates

This paper addresses the aging behaviour of NiCr/CuNiMn/NiCr triple layers on Al₂O₃ ceramics at temperatures up to 200°C for film thicknesses d0.5 μm. Investigations of the film structure and the increase of resistance and its temperature coefficient during the annealing process and studies of the dependence of this aging drift on both the film thickness and the storage temperature have been carried out. Furthermore, the film stress and the effect of substrate bending on resistance have been measured. The results can be explained by the irregular film structure (columns and small bridges between them), which causes stress and current concentrations as well as local creeping, cracking and oxidation processes in the micro-bridges. They are compared with such for structurally homogeneous films on silicon wafers.     

Neuroanatomy in Rett syndrome: cerebral cortex and posterior fossa

Rett syndrome (RS), a neurodevelopmental disorder of unknown etiology occurring almost exclusively in females, is characterized by autistic-like behavior, motor dysfunction, loss of language skills, dementia, and microcephaly. This study is a follow-up and extension of a previously reported neuroimaging study of patients with RS. We replicated previously reported findings with a larger patient population, and the volumetric MRI analysis was extended to include an analysis of neuroanatomy of the posterior fossa. Twenty girls with RS were compared with individually age- and gender-matched normal controls. Patients with RS showed global reduction in gray- and white-matter volumes. The prefrontal, posterior-frontal, and anterior-temporal regions showed the largest bilateral decrease in gray-matter volume, whereas white-matter volume was uniformly reduced throughout the brain. We found confirmation for the preferential reduction in caudate nucleus volume. However, we observed no preferential reduction in midbrain volume despite a preferential reduction in the midsagittal area of this region. We also present an individual case comparison between monozygotic twins discordant for RS.     

Estimation of an Initial Condition of Sigma–Delta Modulators via Projection Onto Convex Sets

In this paper, an initial condition of strictly causal rational interpolative sigma-delta modulators (SDMs) is estimated based on quantizer output bit streams and an input signal. A set of initial conditions generating bounded trajectories is characterized. It is found that a set of initial conditions generating bounded trajectories but not necessarily corresponding to quantizer output bit streams is convex. Also, it is found that a set of initial conditions corresponding to quantizer output bit streams but not necessarily generating bounded trajectories is convex too. Moreover, it is found that an initial condition both corresponding to quantizer output bit streams and generating bounded trajectories is uniquely defined if the loop filter is unstable (Here, an unstable loop filter refers to that with at least one of its poles being strictly outside the unit circle). To estimate that unique initial condition, a projection onto convex set approach is employed. Numerical computer simulations show that the employed method can estimate the initial condition effectively     

Radiosity with Well Distributed Ray Sets

In this paper we present a new radiosity algorithm, based on the notion of a well distributed ray set (WDRS). A WDRS is a set of rays, connecting mutually visible points and patches, that forms an approximate representation of the radiosity operator and the radiosity distribution. We propose an algorithm that constructs an optimal WDRS for a given accuracy and mesh. The construction is based on discrete importance sampling as in previously proposed stochastic radiosity algorithms, and on quasi Monte Carlo sampling. Quasi Monte Carlo sampling leads to faster convergence rates and the fact that the sampling is deterministic makes it possible to represent the well distributed ray set very efficiently in computer memory. Like previously proposed stochastic radiosity algorithms, the new algorithm is well suited for computing the radiance distribution in very complex diffuse scenes, when it is not feasible to explicitly compute and store form factors as in classical radiosity algorithms. Experiments show that the new algorithm is often more efficient than previously proposed Monte Carlo radiosity algorithms by half an order of magnitude and more.