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991.
992.
Drawing on institutional theory, we examine how institutions have influenced technology development trends in the U.S. since the mid-19th century. Based on an inductive analysis of the history of technology development and corporate R&D, we show that both formal and informal institutional rules and constraints played a role in the initial rise of markets for technology, their decline during the early-20th century, and their eventual return at the end of the 20th century. We also find that formal and informal institutions influenced the widespread adoption of in-house R&D labs during the mid-20th century. Our study integrates insights from both the economics and sociology branches of institutional theory. This perspective is particularly useful to analyze historical phenomenon and shifts in trends across long time periods. 相似文献
993.
Meera S. Ghadge Purva P. Naik Bijaynath P. Tiwari Ruprekha M. Hegde Tanaji J. Matale 《Indian journal of clinical biochemistry : IJCB》2012,27(1):97-99
Breast cancer is one of the most frequent malignancies in the world. Available staging procedures to detect breast cancer
are bone scan, chest X-ray, liver ultrasonography, computerized tomography, estimation of tumor markers like carbohydrate
antigen (CA15-3) and carcino embryonic antigen. These procedures are expensive and may not be required in all cases. Out of
70 patients studied, 55 had normal CA15-3 and 15 had elevated levels of Ca15-3. Eight (14.5%) of the 55 patients with normal
CA15-3 had abnormal bone scan. Fifteen patients had CA15-3 levels above the normal range and among these 9 (60%) had abnormal
bone scan. While prime facie it would appear that a high level of CA15-3 correlate with abnormal bone scan, it is also true
that the numbers are small at present and conclusions about the validity of CA15-3 as marker of bone metastasis may be premature. 相似文献
994.
995.
996.
Erich Petushek Chris Richter David Donovan William P. Ebben Phillip B. Watts Randall L. Jensen 《Sports Engineering》2012,15(3):159-166
Quantifying countermovement jump (CMJ) and landing knee flexion angle is important for performance and injury risk assessment. The purpose of the study was to compare electrogoniometer (El-Gon)- and video-derived CMJ and landing knee flexion angle. Twenty-two adults performed three CMJs while knee flexion angle was simultaneously assessed using an El-Gon and video. The average systematic offset (RMSE) of the El-Gon-derived knee flexion angle throughout the entire movement was 7.03°?±?2.69°. Excellent reliability was demonstrated by the El-Gon (ICCavg?=?0.92). Countermovement knee flexion angle, maximum landing knee flexion angle and flexion angle at maximum vertical ground reaction force were 12.0°, 10.9°, and 5.7° higher, respectively, when assessed using El-Gon (p?<?0.001), compared to video. Errors between instruments are likely due to El-Gon crosstalk, misalignment and/or axis determination. The El-Gon is a cost-effective and time-efficient alternative to video analysis for the assessment of knee flexion angle if the error is accounted for and the sensor is precisely attached. 相似文献
997.
Empirical data on the development of interaction, communication, and language in deafblind children is very rare. To fill this gap, a case study was conducted in which the interaction between a teacher and a deafblind boy age 3 years 4 months was analyzed. Sequential analysis of their interaction confirmed some general clinical impressions about interaction with deafblind children, and provided the basis for suggestions on how the interaction pattern might be changed. 相似文献
998.
Kok-Aun?TohEmail author Boon-Tiong?Ho Joseph?P.?Riley Yin-Kiong?Hoh 《Educational Research for Policy and Practice》2006,5(3):187-194
The moulding of the future of a nation depends on the teachers and the education they provide in schools. Research evidence
from the US. National Assessment of Educational Progress (NAEP) confirms this to be the case. Quantitative analysis of data
indicates that measures associated with pre-service teacher preparation are by far the strongest correlates of student achievement
(Darling-Hammond 2000). The research report of Wilson, Floden, and Ferrini-Mundy (2001) also suggests a strong relationship
between teacher preparation and teacher effectiveness. Other research studies similarly indicate that differences in teacher
quality are the most crucial for student achievement when compared with variables such as class size, streaming, or the amount
of homework (Anderson & Helms 2001; Mendro 1998; Powell & Anderson 2002; Rivkin, Hanushek & Kain 2001; Saunders & Horn 1994;
Strong & Tucker 2000) as possible contributory factors. In the pursuit of improved student achievement, we therefore need
to examine seriously the role of teacher variables, ranging from teacher qualifications and their subject matter knowledge,
to what motivates them to take up teaching as a career and as a consequence, how they teach in classrooms. 相似文献
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