The Effect Teaching Experience Has on Perceived Effectiveness of Interactive Television as a Distance Education Model for Elementary School Science Teacher’s Professional Development: Another Digital Divide?

The first year of a 5 year professional development project for elementary teachers in two mid-western states integrated a bridge of two distinctly different distance education networks (T-1 and fiber optics) to provide science professional development for elementary school teachers in rural communities. Interactive television (ITV), the title given to the distance component, consisted of a series of twenty-four, 2 h presentations by scientists and content specialists. It provided expansion to the science pedagogical content knowledge of the elementary teachers involved. Eighty-five teachers in 38 school districts from the two states completed individual surveys following the final ITV session. Analysis of variance of participants post-session survey scores yielded differences (p < 0.05) on the subscales measuring perceived effectiveness of using distance education for professional development purposes and years of teaching experience. Teachers with over 20 years of classroom experience perceived the use of distance education technologies for science professional development to be more effective than teachers with 16–20 years of classroom experience. These results might suggest another digital divide.     

求解化学反应动力学参数的一种方法

反应级数的确定在化学动力学研究中非常重要,现给出了利用计算机和用微分法确定反应级数的方法.为了使编程的程序简短、高效,采用MATLAB语言作为编程语言.     

Fiber optic biosensor of immobilized firefly luciferase

Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. TheK _m′ for D-luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25°C respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10⁻⁹–10⁻⁵ mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.     

Categorical color coding by pigeons

Pigeons were trained on two independent tasks. One involved red and yellow hues, the other involved blue and green hues. For half of the birds, the two tasks were the same (i.e., both tasks were either matching-to-sample, or oddity-from-sample). For the remaining birds, the two tasks were different (i.e., one task was matching-to-sample; the other task was oddity-from-sample). Following acquisition, the pigeons were exposed to test trials on which either the correct or the incorrect comparison hue was replaced with one of the hues from the other task. On yellow-sample trials and on green-sample trials, the pigeons performed as if they had a common code for yellow and green. When there was one comparison available that was appropriate to the “yellow/green” code, performance remained high; but when either both comparisons or neither comparison was appropriate to the “yellow/green” code, performance dropped. The pigeons also tended to code red samples as green and to code blue samples as yellow. The results indicate that pigeons can categorically code colors under conditions that rule out a failure to discriminate among the colors.     

Introduction to this Special Issue

In 2001, for the first time in the history of the International Association for Counselling, International Conference was held in a developing Asian country–India, with the theme Families in Transition–Counselling in Transition–Meeting the Challenges Ahead. This special issue contains some of the presentations made by Indian participants during this conference which best reflect the challenges and diversities of counseling efforts with families in India. The first article was specially written for this issue in order to give an international relationship of this journal an in depth contextual understanding of Indian families in transition and the challenges they pose to the contemporary Indian counselor. Two articles are reflected to counseling families affected by socio-politial and economic changes. Five authors have written on counseling related to physical and mental disability/addiction and last two articles are reflected to authors experiences as family counselors.     

Kinetics study on biomass pyrolysis for fuel gas production

Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme. Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China