The local microenvironment of tissue cells has a profound influence on cell behaviour such as cell shape, guidance of movement, and so on. One approach to understanding this phenomenon, which is being applied by a num...
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The local microenvironment of tissue cells has a profound influence on cell behaviour such as cell shape, guidance of movement, and so on. One approach to understanding this phenomenon, which is being applied by a number of groups, is to model possible cues using microfabrication technology. Such techniques have been used to examine the behaviour of a number of cell types. The responses of fibroblasts, epithelial cells and neurones have been determined on a variety of micropatterned surfaces. Conventional photolithographic techniques and laser holography have been employed to define topographic patterns with feature sizes ranging from 25 mu m to 130 nm. Photolithography, combined with silanization of glass, has been used to chemically pattern surfaces;this results in differentially adhesive surfaces that mimic possible in vivo cues. The determination of the response of various cell types to these various surfaces has provided detailed information on the biological mechanisms controlling cell behaviour, and on aspects of tissue responses to implanted artificial devices;it has also illustrated the potential for technology utilizing immobilized cellular patterns.
Researchers at the University of California at Santa Barbara are devel-oping a personal guidance system that could someday enable visually im-paired travelers to navigate unfamiliar territory without assistance. "
Researchers at the University of California at Santa Barbara are devel-oping a personal guidance system that could someday enable visually im-paired travelers to navigate unfamiliar territory without assistance. "
The results of ultrasound (US)-guided renal parenchymal cutting needle biopsies in 101 consecutive patients were reviewed. The biopsies were done with the automated Biopty device mounted with a 2.0-mm needle. One or 2...
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The results of ultrasound (US)-guided renal parenchymal cutting needle biopsies in 101 consecutive patients were reviewed. The biopsies were done with the automated Biopty device mounted with a 2.0-mm needle. One or 2 needle passes yielded sufficient material for histologic analysis in 94% (95/101). Three or more passes were required in 6% (6/101) to obtain an adequate specimen. Mesangioproliferative glomerulonephritis, IgA-nephropathy, nephrosclerosis, diabetic nephropathy, secondary amyloidosis, lupus nephritis, minimal change glomerulonephritis and interstitial nephritis accounted for 79% of the final histologic diagnoses. The high quality and quantity of the tissue specimens yielded a definitive histologic diagnosis in renal parenchymal diseases of unknown etiology. Four major complications occurred, but no deaths or loss of kidney function were recorded. US proved useful as a guide to suitable biopsy site and in the detection of clinically significant complications. Prebiopsy screening of coagulation variables did not seem to prevent complications. Special attention should be paid to post-biopsy clinical observation.
学校辅导的概念辅导(guidance)是一种专业,目的在助人自助,它随着时代的变迁而不断发展与完善,但其基本原则保持不变。这些原则是:①关心人格发展;②以个人为重心;③强调合作而不用强迫;④尊重个人自由、尊严与价值;⑤是持续的教育。一般提到辅导,多半指的是学校中的进行的辅导工作,根据夏尔与史东(*** and ***)的分析,随着历史事件的变迁,学校辅导的概念,也有所嬗演,每一个概念都有它的社会背景,各有其独到的眼光和重点。学校辅导发展至今,七十多年来,有十二个模式出现。这十二种理论模式,在学校辅导实施中虽偶见到,但都找不到一个纯碎的理论架构,事实上,学校中的辅导实施很少受到单一理论的指导。
Radical changes in the education system in the United Kingdom over the last five years have been wide ranging and include the ending of the statutory probationary period for newly qualified teachers. The first part of...
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The paper begins by reviewing what is known about route choice processes and notes the mismatch between this knowledge and the route choice assumptions embedded in the most widely used assignment models. Empirical evi...
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The paper begins by reviewing what is known about route choice processes and notes the mismatch between this knowledge and the route choice assumptions embedded in the most widely used assignment models. Empirical evidence on the influence of route guidance advice on route choice is reviewed and, despite its limited nature, is seen to suggest that users are reluctant to follow advice unless they find it convincing and that, the more familiar they are with the network, the less likely they are to accept advice. Typically only a small minority of journeys are made in total compliance with advice. Results from an interactive route choice simulator (IGOR) are summarised and are seen to reveal that compliance depends on the extent to which the advice is corroborated by other factors, on the drivers' familiarity with the network and on the quality of advice previously received. It is noted that the IGOR results are in a form which would enable response models to be calibrated. Recent approaches to the modelling of route choice in the context of guidance are discussed. Some are seen to make simplifying assumptions which must limit the relevance of their results;most make no allowance for the fact that drivers are unlikely to comply with all advice and several are not able to represent the benefits which guidance might bring in the context of sporadic congestion or incidents. As an alternative, a two phase model comprising a medium term strategic equilibrium and a day-specific simulation with explicit representation of driver response is proposed.
DURING World War Ⅱ, WASP—the Women’s Airforce Service Pilots—was formed in the American military under the guidance of Jacqueline Cochran, a world-renowned flyer. It began as a small group, but later grew to 1,074...
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DURING World War Ⅱ, WASP—the Women’s Airforce Service Pilots—was formed in the American military under the guidance of Jacqueline Cochran, a world-renowned flyer. It began as a small group, but later grew to 1,074 members. These pilots of different ethnicities looked energetic and dignified in their American air force santiago-blue uniforms pinned with brilliant silver wings badges. Their staunchness
Automated guidance Vehicles' guidance techniques, make use, in most vehicles, of a painted strip or a cable buried in the floor. Free ranging vehicles are now also available in limited types but at prohibitive cos...
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The problem of path keeping of marine vehicles along curved paths is considered. In particular, we are concerned with circular arcs that join two consecutive straight line segments. This provides smooth path changes b...
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The problem of path keeping of marine vehicles along curved paths is considered. In particular, we are concerned with circular arcs that join two consecutive straight line segments. This provides smooth path changes between one segment and the next utilizing a purely geometric reference path construction. Pure pursuit guidance is coupled with orientation angle control law to ensure stability and accuracy. Sensitivity analysis with respect to inaccuracies in the knowledge of the vehicle hydrodynamic characteristics is performed. The results demonstrate the validity of this approach and offer a way to achieve accurate path keeping in confined spaces.
The atmospheric flight of a spacecraft is considered when a aeroassisted orbit change maneuver is performed. Both guidance and control problems are solved and make respectively use of nonlinear control theory and clas...
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The atmospheric flight of a spacecraft is considered when a aeroassisted orbit change maneuver is performed. Both guidance and control problems are solved and make respectively use of nonlinear control theory and classical adaptive control schemes. The originality of the work lies in the consideration of the overall guidance and control problem. A second point which is worth to be noticed is that focus is set on computational time. Whereas gain scheduling is known to be compatible with limited computing power, the main stream in literature consists in implementing some optimizing routines when the guidance problem is tackled. This scheme is dramatically time consuming and is deliberately skipped in the paper; it is replaced by a trajectory tracking guidance policy issued from modem nonlinear control theory. The guidance and control solution is shown to be quite unsensitive to atmospheric density deviations which constitute major unknown parameters in the higher layers of the atmosphere.
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