Flash-lamp annealing of semiconductor materials—Applications and process models

Flash-lamp annealing (FLA) on a millisecond time scale has been shown to be a promising tool in the preparation of high-quality semiconducting materials. The process imposes time varying through-thickness temperature profiles on the substrates being processed, and consequently thermal stresses. A combined thermal and optical model has been developed to predict the substrate temperature distribution and this model has been linked to a structural model to compute stresses and deflections. The paper shows how these models can be used to explore process conditions in flash lamp annealing, with particular regard to the annealing of ion implants in silicon and the crystallization of amorphous silicon layers on glass substrates.     

The amphiphysin family of proteins and their role in endocytosis at the synapse

Clathrin-mediated endocytosis at the plasma membrane is a major pathway of synaptic vesicle recycling in neurones, but little is known about the molecular machinery that orchestrates the process. The amphiphysin protein has recently emerged into the limelight since its discovery in 1992 as a synaptic vesicle-associated protein. It was subsequently found to interact in vitro with the GTPase dynamin through its SH3 domain. However, only in the past year has its role in endocytosis been confirmed, with the demonstration that the introduction of dominant-negative-acting SH3 domains into living cells causes a potent blockade of clathrin-mediated endocytosis. This, together with the discovery by several groups of a second nerve terminal-enriched amphiphysin isoform, and the finding that the two proteins heterodimerize, further suggests that the amphiphysins are closely connected with dynamin-mediated vesicle budding. This review summarizes current views in the field, and draws on data that suggest intriguing alternative roles--including possible involvement in the cytoskeleton and in tumour suppression--for certain members of the amphiphysin family.     

Hip impact velocities and body configurations for voluntary falls from standing height

OBJECTIVE: To determine prevalence of various pheno- and genotypes of Serpulina sp in young pigs in relation to diarrhea and feed medication in Swedish pig-rearing herds. DESIGN: Isolation of spirochetes. Phenotypical and genotypical classification. SAMPLE POPULATION: Young pigs (n = 358) in 19 pigrearing herds. PROCEDURE: Serpulina isolates were classified according to a biochemical scheme based on hemolysis, indole production, hippurate hydrolysis, and alpha-galactosidase, alpha-glucosidase, and beta-glucosidase activities. The 16S rRNA sequences for 10 of the field strains and 2 type strains of Serpulina spp were aligned and compared. Minimum inhibitory concentrations of olaquindox for 9 of the strains were determined. RESULTS: Weakly beta-hemolytic intestinal spirochetes (WBHIS) were isolated from 17 of the herds and 65% of the samples. More than 1 phenotype of WBHIS was found in 12 of the 19 herds. S hyodysenteriae was not isolated in any of the herds. Hippurate-positive WBHIS were isolated in 6 of 7 herds affected by diarrhea, but in only 1 of 8 herds without diarrhea. Hippurate-positive strains were closely related to the pathogenic strain P43 if judged from sequence comparisons. Strains with the same biochemical profile isolated within a herd had identical sequences, but when isolated from different herds, sequence differences were observed. The prevalence of WBHIS was reduced in herds medicated with olaquindox. Investigated field strains had minimum inhibitory concentration values < or = 1 microgram/ml for olaquindox. CONCLUSION: The presence of WBHIS, with the ability to hydrolyze hippurate, was related to diarrhea in pig herds. CLINICAL RELEVANCE: Potentially pathogenic WBHIS can be distinguished from nonpathogenic strains by the hippurate hydrolysis test.     

Protein content and cAMP-dependent phosphorylation of fractionated white perch retina

In the retinas of teleost fish dopamine, released from interplexiform cells, modulates synaptic transmission at both the chemical and electrical synapses of retinal horizontal cells. This modulation is due to activation of adenylate cyclase and phosphorylation by protein kinase A, perhaps of the synaptic ion channel proteins themselves. In this study we have fractionated the white perch retina by Percoll density gradient centrifugation in order to identify proteins which coenrich with horizontal cells. In addition we have tested retinal fractions for phosphorylation by native cAMP-dependent kinase. Our findings indicate that there are at least 3 proteins of molecular weights 28, 43/44 and 50 kDa which coenrich with horizontal cells and 3 proteins of 30/31 kDa, 35 kDa (putative rhodopsin) and 48 kDa (putative arrestin) which coenrich with photoreceptor fractions. The 43/44 kDa phosphoprotein is a target for cAMP-dependent protein phosphorylation and thus is apparently an element of the dopaminergic modulatory pathway in perch horizontal cells.     

A survey of anesthesia support personnel in teaching programs

Although the amount and complexity of equipment and supplies used in the practice of anesthesia have sharply increased in the past decade, the role of technical support personnel dealing with this technology has not been assessed. In an effort to determine that role, a questionnaire survey was conducted of the apportionment, direction, duties, and training of anesthesia technicians in teaching departments. Two-thirds of the inquiries were returned, disclosing a typical allocation of three anesthetizing locations (or 2000 annual anesthetics) per technician. A large majority of these departments have direct control of their technicians. Virtually all of these personnel are responsible for the routine upkeep and setup of anesthesia machines and monitors, although about one-third perform more specialized clinical functions. The preparation of these technicians for their duties varies widely, with almost 60% high school graduates and virtually all reporting training as on-the-job. The authors conclude that the term "anesthesia technician" remains poorly defined and unstandardized, and that current diverse efforts to address this issue deserve attention.     

EvoMiner: frequent subtree mining in phylogenetic databases

The problem of mining collections of trees to identify common patterns, called frequent subtrees (FSTs), arises often when trying to interpret the results of phylogenetic analysis. FST mining generalizes the well-known maximum agreement subtree problem. Here we present EvoMiner, a new algorithm for mining frequent subtrees in collections of phylogenetic trees. EvoMiner is an Apriori-like levelwise method, which uses a novel phylogeny-specific constant-time candidate generation scheme, an efficient fingerprinting-based technique for downward closure, and a lowest-common-ancestor-based support counting step that requires neither costly subtree operations nor database traversal. Our algorithm achieves speedups of up to 100 times or more over Phylominer, the current state-of-the-art algorithm for mining phylogenetic trees. EvoMiner can also work in depth-first enumeration mode to use less memory at the expense of speed. We demonstrate the utility of FST mining as a way to extract meaningful phylogenetic information from collections of trees when compared to maximum agreement subtrees and majority-rule trees—two commonly used approaches in phylogenetic analysis for extracting consensus information from a collection of trees over a common leaf set.     

Delay- and Disruption-Tolerant Networking

Delay- and disruption-tolerant networking (DTN) grew out of attempts to develop an Interplanetary Internet but has evolved into an active area of networking research, with applications in space networking, military tactical networking, and networking for various challenged communities. The DTN Research Group provides an open forum in which DTN researchers and developers can collaborate to further develop this experimental technology.     

改善PLC的兼容性和功能灵活性

兼容性方面的问题可能使整个升级项目趋于停滞。威勒工程公司是一家原始设备制造商(OEM)。当他们在对无菌包装制造机械的驱动系统进行升级时,遇到了新系统与现有控制器之间无法兼容的问题,并因此限制了设备功能的充分发挥。这时,一种具有针对性的PLC整合工程解决方案不仅提供了威勒工程公司所需要的机器操作界面,而且显著提高了PLC应用上的灵活性。     

Frequency multiplexed superconducting quantum interference device readout of large bolometer arrays for cosmic microwave background measurements

A technological milestone for experiments employing transition edge sensor bolometers operating at sub-Kelvin temperature is the deployment of detector arrays with 100s-1000s of bolometers. One key technology for such arrays is readout multiplexing: the ability to read out many sensors simultaneously on the same set of wires. This paper describes a frequency-domain multiplexed readout system which has been developed for and deployed on the APEX-SZ and South Pole Telescope millimeter wavelength receivers. In this system, the detector array is divided into modules of seven detectors, and each bolometer within the module is biased with a unique ～MHz sinusoidal carrier such that the individual bolometer signals are well separated in frequency space. The currents from all bolometers in a module are summed together and pre-amplified with superconducting quantum interference devices operating at 4 K. Room temperature electronics demodulate the carriers to recover the bolometer signals, which are digitized separately and stored to disk. This readout system contributes little noise relative to the detectors themselves, is remarkably insensitive to unwanted microphonic excitations, and provides a technology pathway to multiplexing larger numbers of sensors.