DC characterization of fully ion-implanted p-n junctions intosemi-insulating InP

The forward and reverse characteristics of p⁺-n junctions made by Mg and Si implantation and rapid thermal annealing into Fe-doped semi-insulating InP are described. The effects of the Si dose for obtaining the n-type region, the use of P co-implantation for obtaining the p⁺ region, and the annealing time are studied. The dominant conduction mechanism at forward bias was found to be recombination in the space-charge region, with ideality factors of n=2 down to 198 K, and temperature dependence with an activation energy of 0.76 eV. The reverse characteristics presented junction breakdown at voltages around -20 V, and were accurately described by a thermally-activated trap-assisted tunneling mechanism. The energy of the corresponding trap, obtained by the fitting of the experimental characteristics, was 0.6 eV, and its origin was tentatively ascribed to the Fe deep acceptor present in semi-insulating InP     

Effects of processing on rheology and structure of double cream cheese

Double cream cheese curd was industrially made and post-treated in a pilot scale plant. After storage at 5 °C for 7–9 days, rheological properties of the intermediate and final products were measured using penetrometry, flow curves recording and dynamic testing. Results showed that the curds exhibited timedependent hysteresis of the flow properties and polymer-like dynamic viscoelastic behaviour, independently of the manufacturing stage. Curd mixing at 70 °C and 500 r.p.m. with salt and predenatured whey protein concentrate and dynamic cooling at 20 or 13 °C decreased firmness and dynamic viscoelastic parameters G′ and G″, while tan δ (G″/G′) increased. There was a breakdown of the curd with a decrease in elastic deformation, typical of a solid material and a corresponding increase in viscous flow, characteristic of a liquid. On the other hand, evolution of the rheological parameters was the reverse after heat treatment at 85 °C and homogenization at 20 MPa (first stage) + 5 MPa (second stage). The curd structure was developed with a transition of behaviour to that typical of an elastic solid. Curd cooled dynamically to 13 °C became unstable during subsequent storage. This phenomenon was thought to result from an important breakdown of the curd during dynamic cooling and from aggregation of the milk fat globules during storage.     

Relationship of sociotropy/autonomy and dependency/self-criticism to DSM-III—R personality disorders.

Relationships between A. T. Beck's (1983) constructs of sociotropy/autonomy and S. J. Blatt's (see record 1976-12367-001) constructs of dependency/self-criticism and the Diagnostic and Statistical Manual of Mental Disorders-III (DSM-III) Axis II personality disorders were examined. Two measures of personality styles and a structured diagnostic interview for personality disorders were administered to 138 outpatients. Significant relationships were found between both sets of constructs and a number of personality disorders using both categorical and dimensional measures of Axis II psychopathology. These relationships were consistent with previous theory, supporting recent conceptualizations extending the range of psychopathology associated with these personality styles from depression to the personality disorders. However, the autonomy/self-criticism dimension was correlated with a broader range of personality disorder traits and diagnoses than anticipated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forward electric field calculation using BEM for time-varying magnetic field gradients and motion in strong static fields

A boundary element method for evaluating the electric fields induced in conducting bodies exposed to magnetic fields varying at low frequency has been developed and applied to sources of magnetic field variation that are of relevance in magnetic resonance imaging. An integral formulation based on constant boundary elements which can be used to study the effects of both temporally varying magnetic field gradients and rigid body movement in a static magnetic field is presented. The validity of this approach has been demonstrated for simple geometries with known analytical solutions and it has also been applied to the evaluation of the induced fields in more realistic models of the human head.     

Expression and subcellular distribution of basic fibroblast growth factor are regulated during migration of endothelial cells

Migration of endothelial cells is involved in normal and pathological angiogenesis and in re-endothelialization after vascular injury or rupture of atherosclerotic plaques. Several types of endothelial cells are known to synthesize basic fibroblast growth factor (bFGF); in some of these, migration is increased by exogenous bFGF and inhibited by anti-bFGF antibodies. Using immunocytochemical techniques and RNase protection analysis, we studied endothelial cells from bovine coronary arteries and veins as well as from adrenal microvessels. We found that bFGF mRNA and peptide were present in confluent endothelial cells and were upregulated during migration stimulated by removal of some cells from the monolayer. During migration, extracellular matrix stores of bFGF were depleted, and bFGF immunoreactivity began to accumulate in the cytoplasm of endothelial cells between 2 and 6 hours. After migration had begun, but before the initiation of DNA synthesis, bFGF immunoreactivity increased in the nuclei and nucleoli. Exogenous bFGF stimulated endothelial migration, and antibodies to bFGF markedly inhibited migration, suggesting that an intracrine function of nuclear bFGF is not sufficient for cell migration. In all three types of endothelial cells studied, bFGF was identified as an endogenous regulator, but not as the sole regulator, or migration. Moreover, bFGF expression and subcellular localization were found to be regulated during endothelial cell migration.     

Chordomas of the skull base. Radiologic and clinical evaluation

Chordomas are uncommon skull base tumors, which are locally agressive and are usually not amenable to complete surgical resection. Proton beam irradiation, following surgery, is the preferred treatment modality. For diagnosis and determination of tumor site and extension, CT and MR imaging are the imaging modalities of choice. CT delineates bone destruction and the presence of calcifications and destroyed bone optimally. MR imaging is the modality of choice for better definition of the tumor margin from brain and other soft tissue structures (pharynx) and visualization of blood vessels. The signal intensities and enhancement pattern fail to differentiate chordoma from chondroid chordoma or chondrosarcoma. Chordomas arise from the clivus and therefore are located more centrally, whereas the majority of chondrosarcomas originate in the petroclival fissure and occur more laterally, although occasional overlap occurs in about one third of cases. Immunohistochemical methods allow differentiation of pure chordoma from chondroid chordoma and chondrosarcoma. Chordomas have a lower local control rate than chondrosarcomas.     

A phylogenetic, ontogenetic, and epigenetic view of bio-inspiredhardware systems

If one considers life on Earth since its very beginning, three levels of organization can be distinguished: the phylogenetic level concerns the temporal evolution of the genetic programs within individuals and species, the ontogenetic level concerns the developmental process of a single multicellular organism, and the epigenetic level concerns the learning processes during an individual organism's lifetime. In analogy to nature, the space of bio-inspired hardware systems can be partitioned along these three axes-phylogeny, ontogeny and epigenesis (POE)-giving rise to the POE model. This paper is an exposition and examination of bio-inspired systems within the POE framework, with our goals being: (1) to present an overview of current-day research, (2) to demonstrate that the POE model can be used to classify bio-inspired systems, and (3) to identify possible directions for future research, derived from a POE outlook. We discuss each of the three axes separately, considering the systems created to date and plotting directions for continued progress along the axis in question     

Code Generation for Functional Validation of Pipelined Microprocessors

Functional validation of pipelined microprocessors is a challenging task, as the behavior of a pipeline is determined by a sequence of instructions and by the interaction between their operands. This paper describes an approach to automatic test-program generation based on an evolutionary algorithm. The proposed methodology is able to tackle complex pipelined designs. Human intervention is limited to the formalized listing of the instruction set, and also internal parameters of the test program generator are auto-adapted. A prototype was built and exploited to generate test programs for the DLX/pII, a pipelined microprocessor. For the purpose of these experiments, test programs were devised trying to maximize the RT-level statement coverage. However, the method can be used to generate test programs on different target metrics. Results show the feasibility and effectiveness of the method.