Elementary Teachers’ Perception of Language Issues in Science Classrooms

Although the importance of language in science learning has been widely recognized by researchers, there is limited research on how science teachers perceive the roles that language plays in science classrooms. As part of an intervention design project that aimed to enhance teachers’ capacity to address the language demands of science, interview data (N = 9) were collected to understand teachers’ perceptions and experiences with a wide range of issues related to language use in science classrooms. Adopting an interpretive approach to qualitative data, the analysis revealed that the teachers perceive a wide range of student difficulties related to language use in science classrooms, especially to the use of specialized terms and writing. Although the teachers are keenly aware of how language can be a barrier to learning science, they are less certain as to what students need to know about the language of science in order to master it. The findings suggested professional support that highlights the distinctive language demands of science and how these demands differ from other subject areas could be useful to these elementary school teachers.     

Characteristics of an innovative learning environment according to students’ perceptions: actual versus preferred

An innovative learning environment is the current outcome of the constructivist approach, the essence of which is co-construction of knowledge in an Information and Communication Technology (ICT) environment. We examined how Israeli students perceived 10 characteristics of their classroom learning environment—student cohesiveness, teacher support, involvement, task orientation, investigation, cooperation, equity, differentiation, computer usage and young adult ethos. Particular foci were students’ perceptions of the actual state of their learning environment compared with the preferred state, and which characteristics predicted students’ cooperation. Participants were 1022 students in 33 classes from 12 computerised elementary and middle schools in Israel. Data were collected using the Technology-Rich Outcomes-Focused Learning Environment Inventory (TROFLEI). Results indicated a gap between the actual and the preferred states for all characteristics, although the scope of these gaps differed between elementary-schools students and middle-school students for certain characteristics. Structural equation modelling (SEM) analysis indicated that nine characteristics of the innovative environment in both actual and preferred states were related to cooperation, with these relations being primarily direct with the exception of teacher support and differentiation which had an indirect influence. Teacher support was mediated through student cohesiveness, involvement, equity and young adult ethos, whereas differentiation was mediated through investigation. Evaluation of the innovative learning environment might lead to better insights regarding the behaviours and needs of twenty-first century students in Israel’s education system. These insights could advance constructivist processes and teaching methods and bring the students to effective cooperative learning in an innovative learning environment.     

Educational inequality in Tasmania: evidence and explanations

In this article, we map the extent of educational inequality within Tasmania, and between Tasmania and the rest of Australia, using National Assessment Program—Literacy and Numeracy (NAPLAN) and senior secondary attainment data. This analysis yields some surprising findings, showing the success of Tasmanian primary and high schools and that Tasmanian educational inequality is most strongly expressed at the senior secondary level. We conclude that using such publicly available data to identify differential achievement within and between jurisdictions would strengthen public policy and practitioner interventions aimed at achieving more equal educational outcomes for students in all schools. Our findings also have implications for research directions in this field, suggesting that by analysis of NAPLAN and My School data across individual schools and jurisdictions academic researchers could assist practitioners gain a deeper understanding of inequalities reproduced by the systems they are working within, while finding examples of schools and systems which show a greater level of success in ameliorating disadvantage.     

一种流媒体Caching策略

It is expected that by 2003 continuous media will account for more than 50% of the data available on origin servers, this will provoke a significant change in Internet workload. Due to the high bandwidth requirements and the long-lived nature of digital video, streaming server loads and network bandwidths are proven to be major limiting factors. Aiming at the characteristics of broadband network in residential areas, this paper proposes a popularity-based server-proxy caching strategy for streaming media. According to a streaming media popularity on streaming server and proxy, this strategy caches the content of the streaming media partially or completely. The paper also proposes two formulas that calculate the popularity coefficient of a streaming media on server and proxy, and caching replacement policy. As expected, this strategy decreases the server load, reduces the traffic from streaming server to proxy, and improves client start-up latency.     

International orientierte höhere Schulen in Deutschland – Zwei Varianten von Internationalität im Wechselspiel von Institution und Schülerbiografie

During the last decades, the education system has been marked by distinct processes of internationalisation. In the field of higher education, there are numerous and varied schools with different international profiles. This paper focuses on processes of internationalisation in the German sector of higher education. We contrast two higher secondary schools with international profiles: one international school in a West German metropolitan region with a long tradition and a younger internationally-profiled school located in the periphery of an East German urban centre. This institutional analysis presents school cultural similarities and differences with regard to different claims and concepts of internationality. This analysis is complemented by a reconstruction of three patterns of biographical meaning examining the internationality of pupils and their respective habitual fit to these internationally-profiled schools. We draw on qualitative data, consisting mainly of interviews with head teachers and pupils of these two schools. We argue that these differing regional forms of internationalisation indicate a stratification and hierarchisation in the field of higher education in Germany.     

Modeling of D-STATCOM in distribution systems load flow

This paper presents modeling of Distribution STATCOM (D-STATCOM) in load flow calculations for the steady- state voltage compensation. An accurate model for D-STATCOM is derived to use in load flow calculations. The rating of this device as well as the direction of required reactive power injection for voltage compensation in the desired value (1 p.u.) is de- rived and discussed analytically and mathematically by the phasor diagram method. Furthermore, an efficient method for node and line identification used in load flow calculations is presented. The validity of the proposed model is examined by using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of D-STATCOM for under voltage problem mitigation approach in the distribution networks is determined. The results validate the proposed model for D- STATCOM in large distribution systems.     

Multi-frequency proportional-resonant （MFPR） current controller for PWM VSC under unbalanced supply conditions

This letter presents a multi-frequency proportional-resonant （MFPR） current controller developed for PWM voltage source converter （VSC） under the unbalanced supply voltage conditions. The delta operator is used in place of the shift operator for the implementation of MFPR by using a low-cost fixed-point DSE The experimental results with an alternative control strategy validated the feasibility of the proposed MFPR current controller for the PWM VSC during voltage unbalance.     

Proteomic analysis of human umbilical vein endothelial cells exposed to PM<Subscript>2.5</Subscript>

Exposure to fine ambient particulate matter (PM_2.5) is known to be associated with cardiovascular disease. To uncover the molecular mechanisms involved in cardiovascular toxicity of PM_2.5, we investigated alterations in the protein profile of human umbilical vein endothelial cells (HUVECs) treated with PM_2.5 using two-dimensional electrophoresis in conjunction with mass spectrometry (MS). A total of 31 protein spots were selected as differentially expressed proteins and identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS. The results demonstrated that DNA damage and cell apoptosis are important factors contributing to PM_2.5-mediated toxicity in HUVECs. It is further proposed that PM_2.5 can inhibit superoxide dismutase (SOD) activity and increase reactive oxygen species (ROS) and malonaldehyde (MDA) production in a concentration-dependent manner. Induction of apoptosis and DNA damage through oxidative stress pathways may be one of the key toxicological events occurring in HUVECs under PM_2.5 stress. These results indicated that the toxic mechanisms of PM_2.5 on cardiovascular disease are related to endothelial dysfunction.     

The relationship between parental bonding and peer victimization: examining child stress and hopelessness as mediators

The purpose of the current study was to investigate a two-stage model in which parent-related stress and hopelessness each served as mediators of the relationship between perceived parental bonding and South Korean adolescent peer victimization. This study also examined whether the mediating relationships differed by the gender of parents and adolescents. A casual chain with three links and four sets of variables were analyzed using structural equation modeling. Data were collected from 800 adolescents attending 10 middle schools in the Busan region of South Korea. Results indicated that both maternal and paternal parental bonding were negatively associated with stress, stress was positively associated with hopelessness, and hopelessness was positively associated with South Korean adolescent peer victimization. Most importantly, the significant negative associations between both maternal and paternal parental bonding and peer victimization were mediated by both stress and hopelessness. Furthermore, gender differences in these relationships existed for both parents and adolescents. Limitations and implications to practice were discussed.     

The relation between metastrategic knowledge,strategy use and task performance: Findings and reflections from a numerosity judgement task

In the research literature several positions concerning the role played by metacognition in adaptive strategy choice can be distinguished. While many authors adhere so-called metacognitive models of strategy choice and strategy change, others have questioned the extent to which metacognitive factors are associated with strategy choice and task performance and have proposed alternative theoretical frameworks wherein strategy choices are described in terms of associative models. In the present article we report data coming from a larger research project on the development of children’s numerosity judgement strategies and skills. The experimental task involved judging numerosities of colored blocks presented in a rectangular grid. Participants were 59 second grade and 50 sixth grade children, whose strategic performance data — obtained by means of a systematic analysis of their response-time patterns — were compared with interview data collected at the end of the experiment. The major result of this comparison is that not only the children from the oldest age group, but also the children from the youngest age group showed clear evidence of metacognitive awareness and understanding of different aspects of their strategic performance.