Instructional practices in secondary science: How teachers achieve local and standards-based success

This article reports on analyses of the instructional practices of six middle- and high-school science teachers in the United States who participated in a research-practice partnership that aims to support reform science education goals at scale. All six teachers were well qualified, experienced, and locally successful—respected by students, parents, colleagues, and administrators—but they differed in their success in supporting students' three-dimensional learning. Our goal is to understand how the teachers' instructional practices contributed to their similarities in achieving local success and to differences in enabling students' learning, and to consider the implications of these findings for research-practice partnerships. Data sources included classroom videos supplemented by interviews with teachers and focus students and examples of student work. We also compared students' learning gains by teacher using pre–post assessments that elicited three-dimensional performances. Analyses of classroom videos showed how all six teachers achieved local success—they led effectively managed classrooms, covered the curriculum by teaching almost all unit activities, and assessed students' work in fair and efficient ways. There were important differences, however, in how teachers engaged students in science practices. Teachers in classrooms where students achieved lower learning gains followed a pattern of practice we describe as activity-based teaching, in which students completed investigations and hands-on activities with few opportunities for sensemaking discussions or three-dimensional science performances. Teachers whose students achieved higher learning gains combined the social stability characteristic of local classroom success with more demanding instructional practices associated with scientific sensemaking and cognitive apprenticeship. We conclude with a discussion of implications for research-practice partnerships, highlighting how partnerships need to support all teachers in achieving both local and standards-based success.     

Robust stabilization of nonlinear time delay systems: A complete type functionals approach

The robust stabilization of some classes of nonlinear delay systems with nominal linear delay system is addressed. The form of the controller is not an a priori proposal, but it is the result of a synthesis relying on the use of complete type Lyapunov–Krasovskii functionals, leading to distributed delay linear or nonlinear robust control laws. Simulation results of the stabilization of a chemical refining process demonstrate the good performance of the proposed approaches.     

The Role of Career and Technical Education in Iowa Community Colleges

ABSTRACT

This scholarly paper describes and analyzes the role of career and technical education (CTE) in Iowa community colleges. Iowa's community colleges are doing a good job of responding to the changing workforce needs of the state and providing smooth career pathways. However, changes in the population and economy of the state will call for further changes in CTE programs. The distinctive characteristics of CTE in Iowa community colleges, the impact of community college CTE programs on the state's economy, the role of accountability, and the future implications for CTE in the state are discussed. Recommendations based on the results of the study include improving articulation agreements, increasing retention among at-risk students, and increasing collaboration among Iowa's 15 community colleges.     

Effect of a semi electro-mechanical engine valve on performance and emissions in a single cylinder spark ignited engine

In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption （BSFC）. A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons （HC） and NOx emissions increased by 12% and 13% respectively.     

肌酸激酶与力量训练的实验研究

以速滑运动员为研究对象,观察不同训练水平运动员进行不同强度和不同训练时间的力量训练前后,其体内肌酸激酶(CK)活性的变化.结果表明:只有达到一定训练强度,才可引起体内CK活性的显著变化;不同水平运动员进行大强度力量训练后,均可引起体内CK活性大幅度升高;不同水平运动员进行相同强度(80%、90%)的力量训练后,训练水平较高者较训练水平较低者CK值上升幅度小;相同级别运动员进行不同强度(80%、90%)的力量训练后,训练强度大者较训练强度小者CK活性上升幅度大;相同水平运动员以相同的大强度进行力量训练后,较长时间训练者比短时间训练者,其体内CK值上升得小.进而说明选择测定训练前后CK活性值来判定运动员对力量训练的反应,是较为敏感实用的指标之一.     

The use of portfolios to foster professionalism: attributes,outcomes, and recommendations

The main objective of this research was to review the characteristics of portfolios and their outcomes for teaching professionalism to undergraduate medical students. A systematic review on the use of portfolios in teaching professionalism to medical students identified 1257 papers. Of these, 11 articles met all inclusion criteria. According to the papers, the use of portfolios for teaching professionalism shows versatility, supports learning strategies and has the potential to be used in different contexts, including for formative and summative purposes. The weaknesses were based on the artificiality of the reflections, deficient instructions, time-consuming processes and preference among students for other teaching methods. Students complained about feeling that the reflection was ‘forced’, and they tended to write based on social conventions rather than reveal their true thoughts. Reflection is a powerful component of the portfolio, but the method by which it is taught could easily ruin its potential to boost professionalism. Requiring reflection did not ensure its achievement; increased understanding by students regarding how and why they were doing it, the clarity of assessment methods and constructive feedback might strengthen the potential for success. A framework was designed to support faculty members in developing and applying portfolios with a clear and broad view of this teaching strategy.     

<Emphasis Type="Italic">Dis</Emphasis>closive Ethics and Information Technology: <Emphasis Type="Italic">Disclosing Facial Recognition Systems</Emphasis>

This paper is an attempt to present disclosive ethics as a framework for computer and information ethics – in line with the suggestions by Brey, but also in quite a different manner. The potential of such an approach is demonstrated through a disclosive analysis of facial recognition systems. The paper argues that the politics of information technology is a particularly powerful politics since information technology is an opaque technology – i.e. relatively closed to scrutiny. It presents the design of technology as a process of closure in which design and use decisions become black-boxed and progressively enclosed in increasingly complex socio-technical networks. It further argues for a disclosive ethics that aims to disclose the nondisclosure of politics by claiming a place for ethics in every actual operation of power – as manifested in actual design and use decisions and practices. It also proposes that disclosive ethics would aim to trace and disclose the intentional and emerging enclosure of politics from the very minute technical detail through to social practices and complex social-technical networks. The paper then proceeds to do a disclosive analysis of facial recognition systems. This analysis discloses that seemingly trivial biases in recognition rates of FRSs can emerge as very significant political acts when these systems become used in practice. Paper prepared for the Technology and Ethics Workshop at Twente     

Anthropometric profiles of elite older triathletes in the Ironman Brazil compared with those of young Portuguese triathletes and older Brazilians

The objective of this study was to describe the anthropometric profiles of elite older triathletes participating in the 2009 Ironman Brazil and to compare their somatotype, anthropometric and body composition characteristics with those of elite young triathletes and older non-athletes. The sample consisted of 64 males, divided into three groups: (1) older triathletes (n = 17), (2) young triathletes (n = 24), and (3) older non-athletes (n = 23). Somatotype was analysed according to the Carter and Heath ( 1990 ) method. Body mass index, sum of four skinfolds, percentage body fat, body fat mass, and fat-free mass were also estimated. Older non-athletes had higher endomorphy, sum of four skinfolds, fat percentage, and body fat mass than the athletes. Older athletes who participated in the Ironman and elite young triathletes had higher fat-free mass than older non-athletes. Older triathletes and older non-athletes were considered mainly endomorphic mesomorphs and young triathletes mainly ectomorphic mesomorphs. The findings that characterize the anthropometric profile of athletes in this sports modality could be used as a reference.     

Effects of purposeful soccer heading on circulating small extracellular vesicle concentration and cargo

BackgroundConsidering the potential cumulative effects of repetitive head impact (HI) exposure, we need sensitive biomarkers to track short- and long-term effects. Circulating small extracellular vesicles (sEVs) (<200 nm) traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. The purpose of this study was to identify the microRNA (miRNA) profile in circulating sEVs derived from human plasma following repetitive HI exposure.MethodsHealthy adult (aged 18–35 years) soccer players were randomly assigned to one of 3 groups: the HI group performed 10 standing headers, the leg impact group performed 10 soccer ball trapping maneuvers over 10 min, and the control group did not participate in any soccer drills. Plasma was collected before testing and 24 h afterward, and sEVs were isolated and characterized via nanoparticle tracking analysis. Next-generation sequencing was utilized to identify candidate miRNAs isolated from sEVs, and candidate microRNAs were analyzed via quantitative polymerase chain reaction. In silico target prediction was performed using TargetScan (Version 7.0; targetscan.org) and miRWalk (http://mirwalk.umm.uni-heidelberg.de/) programs, and target validation was performed using luciferase reporter vectors with a miR-7844-5p mimic in human embryonic kidney (HEK) 293T/17 cells.ResultsPlasma sEV concentration and size were not affected across time and group following repetitive HI exposure. After 24 h, the HI read count from next-generation sequencing showed a 4-fold or greater increase in miR-92b-5p, miR-423-5p, and miR-24-3p and a 3-fold or greater decrease in miR-7844-5p, miR-144-5p, miR-221-5p, and miR-22-3p. Analysis of quantitative polymerase chain reaction revealed that leg impact did not alter the candidate miRNA levels. To our knowledge, miR-7844-5p is a previously unknown miRNA. We identified 8 miR-7844-5p mRNA targets: protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B), LIM and senescent cell antigen-like domains 1 (LIMS1), autophagy-related 12 (ATG12), microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), integrin subunit alpha-1 (ITGA1), mitogen-activated protein kinase 1 (MAPK1), glycogen synthase kinase 3β (GSK3β), and mitogen-activated protein kinase 8 (MAPK8).ConclusionCollectively, these data indicate repetitive HI exposure alters plasma sEV miRNA content, but not sEV size or number. Furthermore, for the first time we demonstrate that previously unknown miR-7844-5p targets mRNAs known to be involved in mitochondrial apoptosis, autophagy regulation, mood disorders, and neurodegenerative disease.