Role of cholesterol in regulating apolipoprotein B secretion by the liver

The review examines the evidence that the supply of cholesterol available for incorporation into nascent lipoprotein particles exerts a regulatory influence on apolipoprotein (apo) B secretion by the liver. Support for this hypothesis comes both from in vitro experiments and from recent observations in normal subjects and patients with dyslipidemia associated with familial hypercholesterolemia, obesity, noninsulin dependent diabetes mellitus, growth hormone deficiency and cholesteryl ester storage disease. The findings do not negate a role for triglyceride synthesis in determining apoB secretion in very low density lipoprotein, but the inhibitory effects on the latter process of pharmacological blockade of cholesterol synthesis or esterification suggest that it is conditional upon an adequate supply of cholesteryl ester.     

Silicon carbide-toughened zirconia ceramics

Tetragonal zirconia polycrystalline (TZP) ceramics containing SiC reinforcement in the form of fine particles (nano-scale), particles (micro-scale), whiskers and platelets were synthesized by hot-pressing. The effects of morphology and grain size of SiC reinforcement on the strength and fracture toughness at room temperature were investigated. The addition of SiC (in whatever form) caused decreases in strength and toughness at room temperature with the exception of whisker-reinforced materials. Toughness fell off with increasing temperature, but nevertheless retained about one-half of the room-temperature value for that particular SiC reinforcement. However, the whisker- and particle-reinforced materials had higher K _lc values at high temperature than fine particle- or platelet-reinforced materials, with values in excess of 7 MPa m^1/2 at 1000 °C. The microstructure was examined for SiC whisker-reinforced/TZP materials by TEM and HREM, to examine the nature of the whisker/zirconia interface.     

Performance evaluation of the Golay code pulse compression technique

The Center for NDE, Iowa State University, has developed a laboratory prototype Golay code pulse compression system and tested it on a variety of materials. The performance of the system was evaluated in terms of signal-to-noise ratio enhancement (SNRE), resolution, and computation speed. The system's error sources also were discussed. The Golay code pulse compression was simulated on a computer and demonstrated the effective noise suppression. In addition, an equivalent pulse of the Golay code (delta-like pulse) was derived theoretically using a simple ultrasonic inspection model, which demonstrated its equivalence on the output correlated signal. Overall, the pulse compression technique extended the detection range for a given peak power and considerably reduced the system'swhite noise, hence providing enhanced signal-to-noise ratios (SNRs). An average of 30 dB improvement in SNR was obtained from highly energy-absorbent materials such as rubber, plastics, corks (insulation materials), and thick composites using the Golay codes of up to 512 bits. However, the technique did not effectively reduce coherent scattering noises from the coarse grain boundaries in cast stainless steels, Inconel weld metal, and material lay-ups in thin composites. Furthermore, it was found that, depending upon the system's hardware capabilities, the overall performance could be degraded considerably.     

Role of child and maternal processes in the psychological adjustment of children with sickle cell disease.

In this study, 64% of children aged 7–12 yrs with sickle cell disease were found to have a parent-reported behavior problem, and 50% met the criteria for a Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) diagnosis based on a structured clinical interview of the child. Internalizing types of behavior problems and diagnoses were the most frequent. Support was provided for a transactional stress and coping model in delineating the processes associated with child adjustment. In particular, maternal anxiety accounted for 16–33% of the variance in mother-reported internalizing and externalizing behavior problems, respectively, and child pain-coping strategies accounted for 21% of the variance in child-reported adjustment problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Outbreak of vampire bat biting in a Venezuelan village

An outbreak of 154 cases of vampire bat biting in a four-month period in the gold mine of Payapal, a Venezuelan village, is reported. All patients were bitten during the night and the most bites were on their toes. No complication attributed to the bite was reported. Diagnoses of rabies virus made by means of immunofluorescence were negative. A possible reason for this outbreak may been the development of mining areas, with the inhabitants providing an alternative food source for the bats.     

Reading handwritten digits: a ZIP code recognition system

A neural network algorithm-based system that reads handwritten ZIP codes appearing on real US mail is described. The system uses a recognition-based segmenter, that is a hybrid of connected-components analysis (CCA), vertical cuts, and a neural network recognizer. Connected components that are single digits are handled by CCA. CCs that are combined or dissected digits are handled by the vertical-cut segmenter. The four main stages of processing are preprocessing, in which noise is removed and the digits are deslanted, CCA segmentation and recognition, vertical-cut-point estimation and segmentation, and directly lookup. The system was trained and tested on approximately 10000 images, five- and nine-digit ZIP code fields taken from real mail