Characterization of cellulose acetate micropore membrane immobilized acylase I

This paper describes an innovative method for the immobilization of acylase I, which was entrapped into the CA-CTA micropore membrane. The most suitable casting solutions proportion for immobilizing the enzyme was ob tained through orthogonal experiment. Properties of the enzyme membrane were investigated and compared with those of free enzyme and blank membrane. The thermal stability and pH stability of the enzyme inside the membrane were changed by immobilization. The optimum pH was found to be 6.0, which changes 1.0 unit compared with that of free acylase I. The optimum temperature was found to be about 90 ℃C, which is higher than that of free acylase I (60 ℃). Experimental results showed that immobilization had effects on the kinetic parameters of acylase I.     

A Conceptual Framework for Assessing Motivation and Self-Regulated Learning in College Students

A conceptual framework for assessing student motivation and self-regulated learning in the college classroom is presented. The framework is based on a self-regulatory (SRL) perspective on student motivation and learning in contrast to a student approaches to learning (SAL) perspective. The differences between SRL and SAL approaches are discussed, as are the implications of the SRL conceptual framework for developing instruments to assess college student motivation and learning. The conceptual framework may be useful in guiding future research on college student motivation and learning.     

Seizing the Opportunity to Create Uncertainty in Learning Mathematics

The paper is a reflective account of the design and implementation of mathematical tasks that evoke uncertainty for the learner. Three types of uncertainty associated with mathematical tasks are discussed and illustrated: competing claims, unknown path or questionable conclusion, and non-readily verifiable outcomes. One task is presented in depth, pointing to the dynamic nature of task design, and the added value stimulated by the uncertainty component entailed in the task in terms of mathematical and pedagogical musing.     

Linking Assessment and Intervention for Developmental/Functional Outcomes of Premature,Low-birth-weight Children

Prematurity and low birth weight (LBW) are two major biological factors that put infants and young children at high risk for developmental delays or disabilities. While survival rates for premature and LBW children have improved, incidence figures have changed little over the past 20 years; in fact, the incidence of LBW has increased. Although the vast majority of LBW children have normal outcomes, as a group, they have higher risk for subnormal growth, illnesses, and neurodevelopmental problems. The purpose of this article is to examine the factors that influence the effectiveness of early intervention for premature, LBW children and to describe a strategy for linking assessment and early intervention. Linking assessment and intervention involves comprehensive assessment; a team approach to both assessment and intervention; empowering and enabling families; and the development of functional goals and objectives.     

Secondary Education Systemic Issues: Addressing Possible Contributors to a Leak in the Science Education Pipeline and Potential Solutions

To maintain the legacy of cutting edge scientific innovation in the United States our country must address the many pressing issues facing science education today. One of the most important issues relating to science education is the under-representation of African Americans and Hispanics in the science, technology, and engineering workforce. Foreshadowing such under-representation in the workforce are the disproportionately low rates of African American and Hispanic students attaining college degrees in science and related fields. Evidence suggests disparate systemic factors in secondary science education are contributing to disproportionately low numbers of African American and Hispanic students in the science education pipeline. The present paper embarks on a critical analysis of the issue by elucidating some of the systemic factors within secondary education that contribute to the leak in the science education pipeline. In addition, this review offers a synthesis and explication of some of the policies and programs being implemented to address disparate systemic factors in secondary schools. Finally, recommendations are offered regarding potential mechanisms by which disparities may be alleviated.     

The Relationship Between School Composition,School Process and Mathematics Achievement in Secondary Education in Argentina

Using data from the 1998 High School National Census from the Ministry of Education and Culture of Argentina, the present study examines relationships between school composition, some characteristics of schooling (such as institutional culture and climate), and students’ achievement in Mathematics in the last year of high school. The study applies multilevel linear modeling on the levels of student, school and state. It finds a close relationship between achievement in Mathematics and the variables of school composition and schooling processes. It shows that when both variables act together, the effect of all other variables significantly decreases. The variables of schooling processes, however, even when diminished in influence, nonetheless notably continue to affect students’ achievements. The study also identifes a reference model for future studies evaluating other institutional factors of learning.     

Kindergarten Teachers’ Conceptions of Environmental Education

A written questionnaire was used to obtain information regarding Greek kindergarten teachers’ personal views on the concept of Environmental Education (EE). The questionnaire was also designed to obtain the teachers’ views relative to a series of theoretical and methodological issues concerning the application of EE. It was ascertained that the prevalent conception of the kindergarten teachers includes the following: (a) it is directed towards a knowledge-centered type of EE, (b) it is primarily centered on nature and its protection in terms of EE content, (c) it aims not only to shape citizens willing to adopt environmental measures recommended by the experts, but who will also actively participate in social actions for the protection of the environment, (d) it favors learning procedures in the environment with field study activities, (e) it must be compulsory in the kindergarten level.     

债转股中存在的问题与实施对策

:债转股是国家解决国有企业脱困、盘活边缘性不良资产、化解金融风险的重大经济措施 ,最终目的是将股权变现 ,提高企业的经营管理水平和经济绩效 ,减轻财政负担。但债转股不是债务赦免 ,债转股还存在着许多问题需要解决。我们必须采取有效的对策才能保证债转股工作的正常运行     

Application of stochastic method to optimum design of energy-efficient induction motors with a target of LCC

For an energy-efficient induction machine, the life-cycle cost (LCC) usually is the most important index to the consumer. With this target, the optimization design of a motor is a complex nonlinear problem with constraints. To solve the problem, the authors introduce a united random algorithm. At first, the problem is divided into two parts, the optimal rotor slots and the optimization of other dimensions. Before optimizing the rotor slots with genetic algorithm (GA), the second part is solved with TABU algorithm to simplify the problem. The numerical results showed that this method is better than the method using a traditional algorithm. Project (No. 601299) supported by the Science Foundation of Hebei Province, China.     

Analysis of the cognitive unity or rupture between conjecture and proof when learning to prove on a grade 10 trigonometry course

We present results from a classroom-based intervention designed to help a class of grade 10 students (14–15 years old) learn proof while studying trigonometry in a dynamic geometry software environment. We analysed some students’ solutions to conjecture-and-proof problems that let them gain experience in stating conjectures and developing proofs. Grounded on a conception of proof that includes both empirical and deductive mathematical argumentations, we show the trajectories of some students progressing from developing basic empirical proofs towards developing deductive proofs and understanding the role of conjectures and proofs in mathematics. Our analysis of students’ solutions is based on networking Boero et al.’s construct of cognitive unity of theorems, Pedemonte’s structural and referential analysis of conjectures and proofs, and Balacheff and Margolinas’ cK¢ model, while using Toulmin schemes to represent students’ productions. This combination has allowed us to identify several emerging types of cognitive unity/rupture, corresponding to different ways of solving conjecture-and-proof problems. We also show that some types of cognitive unity/rupture seem to induce students to produce deductive proofs, whereas other types seem to induce them to produce empirical proofs.