Reasoning about data in middle school science

This case study illustrates instruction in an urban 6th‐grade classroom in which students were learning about mass, volume, and density by attempting to layer (stack) three miscible solutions with differing densities atop one another. The study examines classroom discourse and interaction on the basis of four teaching goals: (a) reaching consensus about which stacks were possible, (b) developing persuasive arguments that separated data from noise, (c) establishing social norms for collective inquiry, and (d) appreciating the epistemological status of scientific knowledge. The study traces the fate of three stacks that students claimed were possible after initial investigations with the solutions. These claims underwent a process of collective validation in which consensus without coercion was the goal, which illustrates emergent standards for backing claims with evidence, as well as for replicability, among the students. Students were successful in achieving three of the four goals, with some qualifications. In relation to Goal 3, which required generalization to other situations, somewhat less success is reported. Limitations in the current standards, difficulties of time allotment in current curricula, and establishing classroom cultures of inquiry are discussed. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 179–199, 1999     

Internalizing symptoms and affect of children with emotional and behavioral disorders: A comparative study with an urban African American sample

Self‐reported internalizing symptoms of seriously emotionally disturbed (SED) and regular education students in grades 4–6 were compared using the Internalizing Symptoms Scale for Children. All participants were African American and from an urban public school district in the Southeastern United States. Each of the two study groups consisted of 50 participants (35 boys, 15 girls) who were matched by gender and socioeconomic status. The SED group reported significantly higher levels of internalizing distress than the regular education group. In contrast to previous findings, there was no significant gender difference in self‐reported internalizing symptomatology in the present study. A discriminant function analysis found that the ISSC scores were able to correctly classify 91% of the participants into their respective educational group. Results of this study provide additional evidence of the construct validity of the ISSC, a recently developed and unique self‐report measure. Results are discussed in terms of future research needs and educational/clinical practice with students who have emotional and behavioral disorders. © 1999 John Wiley & Sons, Inc.     

我国义务教育人员性投入价格指数的构造与应用——以城镇地区为例

本文利用2005年全国1%人口抽样调查数据,通过构建模型,对我国义务教育投入中占最大比例的人员性投入的价格差异及其在地区间的配置状况进行了研究。实证结果表明,我国城镇地区间义务教育人员性投入的价格差异很大,生均人员性投入的实际差异远小于生均教育经费中个人部分的支出差异。但城镇地区间生均人员性投入差异依然存在,因此,政府仍需努力促进地区间义务教育财政公平的实现,并对地区间义务教育价格指数进行常规测算,以掌握教育资源的真实配置状况。     

Teaching Lean Six Sigma within A Supply Chain Context: The Airplane Supply Chain Simulation

Lean six sigma is a management methodology that firms can employ to achieve substantial improvement in supply chain performance. However, few pedagogical exercises facilitate students’ use of a comprehensive set of lean six sigma principles within a supply chain context. We describe the Airplane Supply Chain Simulation that helps students understand how lean six sigma concepts may be leveraged to improve supply chain performance. The basis of this simulation is a four‐tier supply chain, consisting of suppliers (two tiers), a manufacturer, and a customer, that produces three models of paper airplanes to meet randomly distributed customer demand. In the first of three successive runs, a highly structured simulation is executed in which supply chain roles are well defined, material flows are convoluted, and a “push” production strategy is followed. The first simulation as the “current state” and, for the second and third simulation runs, challenge competing student teams to leverage lean six sigma concepts to develop a “future state” that enables the fulfillment of all customer orders at the lowest cost. Results based on statistical analyses of survey response data from 194 MBA students show that the Airplane Supply Chain Simulation is an effective participative, team‐based learning tool.     

A Critical Challenge: The Engagement and Assessment of Contingent,Part-Time Adjunct Faculty Professors in United States Community Colleges

In 2011, according to a National Center for Education Statistics report, part-time instructional staff in all higher education institutions exceeded full-time faculty members for the first time, accounting for 50% of all instructional staff (National Center for Education Statistics [NCES], 2012 National Center for Education Statistics . ( 2012 ). IPEDS, Digest of education statistics, Winter 2011–12, human resources component, fall staff section: Table 286 [data file]. Retrieved from http://nces.ed.gov/programs/digest/d12/tables/dt12_286.asp  [Google Scholar]). The same report indicates part-time faculty in community colleges exceeds 70% of instructional staff. Perhaps more alarming are the numbers of contingent instructional staff—faculty without long-term employment commitments. According to this measure, nearly 70% of faculty members in all areas of higher education have little-to-no job stability (American Association of University Professors [AAUP], 2013 American Association of University Professors (AAUP) . ( 2013 ). Background facts on contingent faculty. Retrieved from http://www.aaup.org/issues/contingency/background-facts  [Google Scholar]; Schuster & Finklestein, 2006 Schuster , J. H. , & Finklestein , M. J. ( 2006 ). The American faculty: The restructuring of academic work and careers . Baltimore , MD : The Johns Hopkins University Press . [Google Scholar]). However, limited research exists on the working experiences of this major subpopulation of United States professors.

The purpose of this qualitative study was to explore the experiences of part-time contingent community college faculty regarding the assessment processes their institutions implemented. Through interviews, researchers gathered data identifying what 20 part-time contingent faculty professors reported regarding teaching conditions and institutional assessment procedures. Participant interviews revealed two major themes centered on a lack of institutional engagement and meaningful assessment policies or procedures.     

Evaluation of urinary abnormalities in urolithiasis patients: A study from North India

Metabolic abnormalities were investigated in 44 stone patients with first time (group 1) and 56 with 2 times stone formation (group 2), and in 25 normal individuals. 24hr urine was analysed spectrophotometrically for oxalate, calcium, magnesium, citrate, uric acid, phosphate and creatinine. Hypocitraturia and hyperoxaluria were the common abnormalities in the stone formers. Stone patients had significantly higher urinary oxalate, calcium and uric acid and lower phosphate than normal individuals. Citrate/calcium and magnesium/calcium ratio were significantly high in normal individuals than stone formers. Patients in group 2 excreted significantly higher urinary calcium and lower citrate that patients in group 1. Citrate/calcium ratio was higher in group 1 than group 2. Hypocitraturia, hyperoxaluria, hypercalciuria and increased citrate/calcium and magnesium/calcium ratio seem to be an essential risk factor for stone formation. Patients with recurrent stone formation could be distinguished from patients with first time stone formation on the basis of urinary calcium and citrate.     

How medical practice evolves: Learning to treat failing hearts with an implantable device

In this article we propose that medical practice evolves as a result of progress along three different pathways: improvement in the ability to develop effective medical technologies, learning in medical practice, and advances in biomedical scientific understanding of disease. The relative importance of these three pathways varies from case to case, and often they interact strongly. More specifically, we argue here that in cases of therapeutic innovation where a new medical technology is involved the advance in medical practice is driven largely by the ability to develop and use effective medical artifacts and the interactive sequence among these interdependent pathways often starts with what is learned in practice and not in science. While we state this argument in general, we develop it in detail in a longitudinal and contextual case study of the emergence and evolution of a treatment for advanced heart failure based on an implantable device, the Left Ventricular Assist Device (LVAD). Our findings show that an essential aspect of the evolution of the LVAD therapy is collective and cumulative learning that requires experience that only can be gained through the actual use of LVADs. We discuss the theoretical and policy implications that follow from our understanding of how medical practice evolves for research on the evolution of medical practices and new medical technologies, and policies about the evaluation of rapidly moving medical practices and clinical research involved in their advancement.     

The dynamics of the impact and coalescence of droplets on a solid surface

A simple experimental setup to study the impact and coalescence of deposited droplets is described. Droplet impact and coalescence have been investigated by high-speed particle image velocimetry. Velocity fields near the liquid-substrate interface have been observed for the impact and coalescence of 2.4 mm diameter droplets of glycerol∕water striking a flat transparent substrate in air. The experimental arrangement images the internal flow in the droplets from below the substrate with a high-speed camera and continuous laser illumination. Experimental results are in the form of digital images that are processed by particle image velocimetry and image processing algorithms to obtain velocity fields, droplet geometries, and contact line positions. Experimental results are compared with numerical simulations by the lattice Boltzmann method.     

Adaptive output feedback neural network control of uncertain non-affine systems with unknown control direction

This paper deals with the problem of adaptive output feedback neural network controller design for a SISO non-affine nonlinear system. Since in practice all system states are not available in output measurement, an observer is designed to estimate these states. In comparison with the existing approaches, the current method does not require any information about the sign of control gain. In order to handle the unknown sign of the control direction, the Nussbaum-type function is utilized. In order to approximate the unknown nonlinear function, neural network is firstly exploited, and then to compensate the approximation error and external disturbance a robustifying term is employed. The proposed controller is designed based on strict-positive-real (SPR) Lyapunov stability theory to ensure the asymptotic stability of the closed-loop system. Finally, two simulation studies are presented to demonstrate the effectiveness of the developed scheme.     

Sub-nanomolar detection of thrombin activity on a microfluidic chip

Bioluminescence resonance energy transfer (BRET) is a form of Förster resonance energy transfer. BRET has been shown to support lower limits of detection than fluorescence resonance energy transfer (FRET) but, unlike FRET, has not been widely implemented on microfluidic devices for bioanalytical sensing. We recently reported a microscope-based microfluidic system for BRET-based biosensing, using a hybrid, high quantum-efficiency, form of BRET chemistry. This paper reports the first optical fiber-based system for BRET detection on a microfluidic chip, capable of quantifying photon emissions from the low quantum-efficiency BRET² system. We investigated the effects of varying core diameter and numerical aperture of optical fibers, as well as varying microfluidic channel design and measurement conditions. We optimized the set-up in order to maximize photon counts and minimize the response time. The optimized conditions supported measurement of thrombin activity, with a limit of detection of 20 pM, which is lower than the microscope-based system and more than 20 times lower than concentrations reported to occur in plasma clots.