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991.
Shanan Fitts Lisa Winstead Evelyn M. Weisman Susana Y. Flores Christine Valenciana 《Equity & Excellence in Education》2013,46(3):357-371
This study examined the development of bicultural voice in Latina/o preservice teachers. Researchers used survey, interview, and observational data to probe students' knowledge, beliefs, and orientations related to teaching culturally and linguistically diverse students. The researchers found that the bilingual cohort courses afforded students with opportunities to juxtapose personal narratives with broader social contexts, thereby allowing students to examine and critique the ideology and curricula of schools. The authors assert that cultivating social justice orientations in bilingual-bicultural preservice teachers is crucial to the empowerment of bilingual-bicultural teachers and their students. 相似文献
992.
Turbulence in the wake generated by wind flow over buildings or obstacles may produce complex flow patterns in downstream areas. Examples include the recirculating flow and wind deficit areas behind an airport terminal building and their potential impacts on the aircraft landing on nearby runways. A computational fluid dynamics (CFD) simulation of the wind flow over an airport terminal building was performed in this study of the effect of the building wake on landing aircraft. Under normal meteorological conditions, the studied airport terminal building causes limited effects on landing aircraft because most of the aircraft have already landed before entering the turbulent wake region. By simulating the approach of a tropical cyclone, additional CFD sensitivity tests were performed to study the impacts of building wake under extreme meteorological conditions. It was found that, in a narrow range of prevalent wind directions with wind speeds larger than a certain threshold value, a substantial drop in wind speed (〉3.6 m/s) along the glide path of aircraft was observed in the building wake. Our CFD results also showed that under the most critical situation, a drop in wind speed as large as 6.4 m/s occurred right at the touchdown point of landing aircraft on the runway, an effect which may have a significant impact on aircraft operations. This study indicated that a comprehensive analysis of the potential impacts of building wake on aircraft operations should be carried out for airport terminals and associated buildings in airfields to ensure safe aviation operation under all meteorological conditions and to facilitate implementation of precautionary measures. 相似文献
993.
OBJECTIVE: The research describes and compares patterns of maltreatment recurrence across multiple states using large samples, confirms the patterns of recurrence found in the literature, and explores unreported patterns of recurrence. METHOD: A recurrence data set for calendar years 1994 and 1995 was constructed from the multi-state case level data from the National Child Abuse and Neglect Data System. These data were available for 10 states and included a range from 2,419 to 99,288 substantiated or indicated report-child pairs per state. A common set of data constructs lent consistency to data construction and analysis, while preserving differences in policy. Event History Analysis (survival) techniques were used. RESULTS: Single site studies were confirmed across the 10 states. These include the pattern where neglect is most likely to recur, followed by physical abuse and then sexual abuse. Similarly, younger children are more likely to recur. A finding of the analysis is that the likelihood of recurrence increases in a systematic and consistent fashion based upon the sequential ordering of recurrent maltreatment events. Also, the likelihood of recurrence is associated with the provision of postinvestigative services. CONCLUSION: Highly consistent patterns of recurrence were observed across states. Children experiencing multiple recurrences compared to no recurrence or one recurrence may represent a special at risk population requiring additional research. Adequate baselines and an understanding of recurrence is needed when considering recurrence as an outcome indicator or in developing risk assessment tools. Important recurrence patterns may be difficult to detect reliably with relatively small samples. 相似文献
994.
ZHUZ.Q. SHIY.F HOWED. 《浙江大学学报(A卷英文版)》2005,6(2):83-89
The flux-weakening performance of a permanent magnet brushless AC drive was investigated using both floating-point and fixed-point DSP controllers. A significant current oscillation was observed when the drive was operated at high-speed in the flux-weakening mode with the fixed-point DSP. The investigation showed that this was due to the on-line compensation of the winding resistance voltage drop and quantisation errors associated with the fixed-point architecture of the DSP. A simple look-up table scheme is proposed to eliminate the oscillation and to achieve extended flux-weakening capability. 相似文献
995.
Ursula Y. Johnson Veronica Martinez-Cantu Arminta L. Jacobson Carla-Marie Weir 《Early education and development》2013,24(5):713-727
Research Findings: This study investigated the relationship of the Home Instruction for Parents of Preschool Youngsters (HIPPY) program to mothers' involvement in education at home and school, student school readiness in kindergarten, and student academic outcomes at 3rd grade. HIPPY serves a mostly minority, low-income family population and employs home visitors that are mostly female and Spanish speaking. Using a within-group analysis, we found that HIPPY mothers increased educational activities in their home with their children after 1 year of home-based intervention. The majority (84.8%) of HIPPY kindergartners were rated as “ready for school” by their kindergarten teachers according to a within-group analysis. In addition, between-group analyses showed that HIPPY kindergartners had higher attendance rates, higher prekindergarten enrollment, and higher promotion to 1st grade compared to other kindergartners in the school district. HIPPY 3rd graders scored significantly higher on a state-mandated math achievement test than their matched peers. Practice or Policy: The results suggest that HIPPY had a positive relationship with families and schools through improved parent involvement and student school outcomes. 相似文献
996.
Emad Y. Moawad 《Indian journal of clinical biochemistry : IJCB》2014,29(4):442-451
The purpose of this study is optimizing the l-arginine (l-Arg) doses on the basis of chemical structure in regional accessible tumor therapy to settle down a new protocol for the treatment of cancer. 3H-thymidine-based cell proliferation assay was performed in vitro on tumor cell lines of fibrosarcoma (FS), lymphosarcoma-ascitic and on normal cell line of NIH 3T3 after treatment with different concentrations of l-Arg in phosphate buffered saline (PBS). The cultures were harvested after 22 h and the incorporated radioactivity was counted to identify their histologic grades as described in earlier studies. In vivo therapy of murine tumors was conducted where FS cells injected subcutaneously at ventro-lateral position of mice. Various drug delivery schedules were injected into the centre of tumor base, once a day for 4 days. Tumor diameter and survivals were monitored where the day of sacrifice was considered for monitoring the survival period. By identifying the histologic grades of the treated cultures in vitro and in vivo by different concentrations of l-Arg, the corresponding energy of such concentrations were determined. An efficient model with a good fit (R2 = 0.98) was established to describe the energy yield by l-Arg dose. The equivalence between the tumor histologic grade and energy of the l-Arg dose delivered in saline (PBS) environment is the optimum condition for regional tumor therapy achieves higher survival rate. The selective cytotoxicity to tumor cells with minimal damage to normal cells by l-Arg due to its chemical structure suggests to be considered the most promising drug for regional therapy of the accessible tumors like breast cancers of early stage with no distant metastasis. 相似文献
997.
Blanca S. Leon Alma Y. Alanis Edgar N. Sanchez Fernando Ornelas-Tellez Eduardo Ruiz-Velazquez 《Journal of The Franklin Institute》2012,349(5):1851-1870
In this paper, inverse optimal neural control for trajectory tracking is applied to glycemic control of type 1 diabetes mellitus (T1DM) patients. The proposed control law calculates the adequate insulin delivery rate in order to prevent hyperglycemia and hypoglycemia levels in T1DM patients. Two models are used: (1) a nonlinear compartmental model in order to obtain type 1 diabetes mellitus virtual patient behavior, and (2) a neural model obtained from an on-line neural identifier, which uses a recurrent neural network, trained with the extended Kalman filter (EKF); the last one allows the applicability of an inverse optimal neural controller. The proposed algorithm is tuned to track a desired trajectory; this trajectory reproduces the glucose absorption of a healthy person. The applicability of the proposed control scheme is illustrated via simulations. 相似文献
998.
999.
The relative contributions of higher education and schools, and hence the conceptual and practical aspects of ITE, to student teachers’ professional learning have been an issue of concern in teacher education. This article reports a mixed-methods study showing the relationship between student teachers’ engagement with the practical and conceptual aspects of a Postgraduate Diploma in Education (PGDE) Programme in Hong Kong and different facets of their perceived professional competence. One hundred and thirty-two student teachers participated in the quantitative survey of whom seven were interviewed. The findings reveal that experiences associated with learning the pragmatic facets of professional practice were more valued by student teachers compared to learning the conceptual aspects of ITE. Yet, in terms of relationship with professional competence, student teachers’ engagement with the practical aspects of ITE was related to competence in classroom teaching, whereas their engagement with the conceptual aspects contributed to their mastery of professional knowledge, competence in classroom teaching and competence in interacting with stakeholders. The study illuminates the distinctive contributions of schools and higher education in ITE. While acknowledging the important role of schools in providing a setting for practical work, this study affirms the distinctive contribution of higher education in equipping student teachers with practical and conceptual tools in the preparation of professionally competent teachers. 相似文献
1000.