Scaling behavior of nucleotide cluster in DNA sequences

In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P（S） ∝ e^-αs＇ where S represents nucleotide cluster size. The cluster-size distribution P（S1＋S2） with the total size of sequential C-G cluster and A-T cluster S1＋S2 were also studied. P（S1＋S2） follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L（n） and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.     

Novel high torque bearingless two-sided rotary ultrasonic motor

Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide suffi-ciently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting of a two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using ex-perimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.     

Motivation across domains: Do goals and attributions change with subject matter for Grades 4 and 5 students?

This study explored a theory for motivation which included aspects of both attribution theory and goal theory. Motivational variables included beliefs about intelligence (entity or incremental), goal orientation (mastery/learning, performance-approach, performance-avoidance) and avoidant behaviours. Grades 4 and 5 students from a large, metropolitan school district were surveyed regarding these motivational variables across the academic domains of reading and mathematics. The relationships among these motivational variables were explored, as well as differences across domains. A diverse sample allowed differences across ethnic groups and socioeconomic status to be studied. Results indicate that children could have a generalised notion of motivation that becomes differentiated when students are asked to reflect on these variables within specified domains. The existence of few differences across ethnic and socioeconomic groups suggest that instructional style could be a more powerful influence than either of these variables.     

The international performance of the South African academic institutions: a citation assessment

This article reports the results of an investigation to identify the disciplinary strengths and the international standing of the higher education institutions in South Africa. Even though comparative assessments provide valuable information for research administrations, researchers and students such information is not available in South Africa currently. The Essential Science Indicators database of the Institute for Scientific Information is utilized for the investigation and six South African universities are identified to be included in the top 1% of the world’s institutions cited in the international scientific literature. The identified institutions are University of Cape Town, University of Pretoria, Orange Free State University, University of Witwatersrand, University of Natal and University of Stellenbosch. Analysis of the scientific disciplines in which the South African institutions meet the threshold requirements for inclusion in the database shows that the country has citation footprints in only nine of the 22 broad scientific disciplines. The article identifies the international standing of the South African universities in the various scientific disciplines, and elaborates on the consequences relevant to higher education and science and technology policy.     

Teaching for transfer of core/key skills in higher education: Cognitive skills

This article is a result of a completed survey of the mainly cognitive science literature on the transferability of those skills which have been described variously as ‘core’, ‘key’, and ‘generic’. The literature reveals that those predominantly cognitive skills which have been studied thoroughly (mainly problem solving) are transferable under certain conditions. These conditions relate particularly to the methods and environment of the learning of these skills. Therefore, there are many implications for the teaching of key skills in higher education, which the article draws out, following a summary of the main findings of the research literature. Learning of principles and concepts facilitates transfer to dissimilar problems, as it creates more flexible mental representations, whereas rote learning of facts discourages transfer. Transfer is fostered when general principles of reasoning are taught together with self-monitoring practices and potential applications in varied contexts. Training in reasoning and critical thinking is only effective for transfer, when abstract principles and rules are coupled with examples. Transfer is promoted when learning takes place in a social context, which fosters generation of principles and explanations. Transfer improves when learning is through co-operative methods, and where there is feedback on performance with training examples. The specificity of the context in which principles are learned reduces their transfer. Transfer is promoted if learners are shown how problems resemble each other, if they are expected to learn to do this themselves, if they are aware of how to apply skills in different contexts, if attention is directed to the underlying goal structure of comparable problems, if examples are varied and are accompanied by rules or principles (especially if discovered by the learners), and if learners’ self-explanations are stimulated. Learning to use meta-cognitive strategies is especially important for transfer.     

Gleichstellung von Frauen und Männern an vollrechtsfähigen Universitäten

Trotz hoher Studentinnen- und Absolventinnenzahlen in den meisten Studienrichtungen ist der Anteil der Frauen an akademischen Spitzenpositionen noch immer gering. Die Gründe für dieses Missverhältnis liegen in einer Reihe spezifischer Schwierigkeiten, mit denen Frauen bei universitären Laufbahnen konfrontiert sind. Die Politik der Europäischen Union verfolgt seit 1999 das explizite Ziel, Frauen stärker in der universitären und außeruniversitären Forschung zu verankern. Mit dem Vertrag von Amsterdam wurde auch der gemeinschaftsrechtliche Rahmen neu gestaltet. Das UG 2002 hat "Frauenförderung" und "Gleichstellung von Frauen und Männern" zur Aufgabe der Universitäten und damit zu einem zentralen Teil ihres Bildungsauftrags erklärt. Die Europäische Strategie des "Gender Mainstreaming" wurde so in eine innerstaatliche, alle Universitätsorgane bindende Verpflichtung umgesetzt. Der Beitrag behandelt die rechtlichen Möglichkeiten der vollrechtsfähigen Universitäten zur Frauenförderung und bewertet Reichweite und Wirksamkeit der neuen Rechtslage.     

Life in the oceanic realms

The marine environment includes the nutrient-rich coastal waters, relatively nutrient-poor open oceanic waters, coral reef atolls, metal-rich hydrothermal vent fluids with temperatures of 200–350°C, cold-seeps, estuaries, mangrove swamps, intertidal beaches and rocky shores. Oceans are home to some of themost diverse and unique life forms. This article is an attempt to introduce some of the fundamentals of biologicaloceanography andmarine biologyto describe life in the sea.     

The persistence of preschool effects: Do subsequent classroom experiences matter?

Using rich longitudinal data from the Early Childhood Longitudinal Study-Kindergarten cohort (ECLS-K), we find that children who attended preschool enter public schools with higher levels of academic skills than their peers who experienced other types of child care (effect size of .14). This study considers the circumstances under which the preschool advantage persists, that is, the types of classrooms in which students who did not attend preschool “catch up” to their counterparts who did. Specifically, we focus on two dimensions of the early school environment—class size and the level of academic instruction provided. The findings suggest that most of the preschool-related gap in academic skills at school entry is quickly eliminated for children placed in small classrooms and classrooms providing high levels of reading instruction. Conversely, the initial disparities persist for children experiencing large classes and lower levels of reading instruction. These results point out that the longer-term effects of early childhood experience partly depend on classroom experiences during at least the first years of school.     

Teacher and school characteristics and their influence on curriculum implementation

Reform‐based curriculum materials have been suggested as a mechanism to make inquiry‐based instruction more prevalent in secondary science classrooms, specifically when accompanied by comprehensive professional development (Loucks‐Horsley, Hewson, Love, & Stiles, 1998 ; Powell & Anderson, 2002 ). This research examines the implementation of a reform‐based high school chemistry curriculum in a large, urban school district. We explicitly consider the role of the teachers' knowledge and beliefs in their implementation of the reform‐based chemistry curriculum, as well as school level factors. Qualitative and quantitative data were collected in the form of beliefs interviews and classroom observations from 27 high school chemistry teachers. Analysis of the data revealed that implementation of the curriculum was strongly influenced by the teachers' beliefs about teaching and learning, and the presence of a supportive network at their school sites. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 883–907, 2007