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.     

Comparative studies on the biochemical characteristics of natural actomyosin isolated from PSE and normal pork

Biochemical changes of natural actomyosin from fresh pale, soft, exudative (PSE) and normal pork were studied, and the effects of different storage temperatures and different incubation temperature and times on sample superprecipitation, total sulfhydryl (-SH) content, and ATP (adenosine triphosphate) sensitivity were investigated. The results demonstrated that ATPase activity and thermal stability of PSE actomyosin were lower than those of normal pork; and that PSE actomyosin had higher -SH content than that of normal pork at all incubation temperatures and times tested.     

Defiant Behavior in Two- and Three-Year-Olds: A Vygotskian Approach

Defiant behavior in two- and three-year-olds is a natural expression of a young child’s growing autonomy, and, although frustrating to adults, is a natural phase of a child’s socio-emotional growth. L.S. Vygotsky’s socio-historical theory of the development included a discussion of “crisis” periods, one of which he felt occurred at age three. The crisis that Vygotsky asserted occurred at three is characterized by a group of seven “behaviors”, all of which indicate a struggle with the child’s position in relation to family social structures. This study examined the occurrences and characteristics of defiant behavior in two-and three-year-old children during outdoor play at a child development center, and the existence and context of defiant behaviors the modern childcare setting. Patterns in defiant behaviors during play in different age groups were apparent, and suggested an instrument to facilitate the documentation and analysis of defiant behavior in modern group-care settings.     

A linguistic and neuropsychological approach to remediation in a german case of developmental dysgraphia

There have been relatively few single case studies concerned with the remediation of spelling deficits among developmental impairments. Among these there have been a small number that targeted specific components of the spelling process and used linguistic theories as theoretical underpinning for the development of remediation procedures. This single case study examines remediation of writing skills and aims at evaluating two different lexically based intervention methods, one of which used Optimality Theory as its basis. We applied a rule-based remediation and an intervention method using whole-word forms to a child with selective impairments in the lexical-graphemic components. The investigation was done with words in which phoneme-grapheme-correspondences in word final position change due to voicing neutralization. The individual exhibited a method- and item-specific effect with respect to the rule-based method. In addition, a transfer effect to untreated items and a generalization effect to untrained but related tasks was observed. The absence of a method-specific and a generalization effect for the whole-word form intervention and the success of the rule-based method is determined by the specific cognitive component(s)s that constitute the source of the deficit and the appropriateness of Optimality Theory to address this particular deficit.     

College Students’ Experiences with Diversity and Their Effects on Academic Self-Confidence,Social Agency,and Disposition toward Critical Thinking

The results of this study conducted at the University of Michigan (n = 289) indicate that students with more experiences with diversity, particularly enrollment in diversity courses and positive interactions with diverse peers, are more likely to score higher on academic self-confidence, social agency, and critical thinking disposition. In addition, the study provides evidence that diversity experiences may work together to foster development of certain aspects of self.The work reported herein is supported under the National Institute for Student Achievement, Curriculum and Assessment program, agreement number R305T990402-00, CFDA/Subprogram No: 84.305T, as administered by the Office of Educational Research and Improvement (OERI), U.S. Department of Education. The findings and opinions expressed in this report do not reflect the position or policies of OERI or the U.S. Department of Education.     

Use of flow cytometry to investigate the cytokine response pattern in infants with respiratory syncytial virus infection and bronchiolitis

Objective: To investigate the cytokine response pattern (IL-4/IFN-γ) in infants with RSV infections and bronchiolitis during the acute phase. Methods: Four-color flow cytometry was used to measure intracellular IL-4 and IFN-γ expressions in peripheral blood CD3+ and CD8+ lymphocytes from RSV-infected and bronchiolitis infants. Serum IL-4 and IFN-γ levels were also determined. Results: RSV-infected and bronchiolitis infants showed no statistical differences from not-RSV-infected or pneumonia infants and control in the frequency of IL-4 and IFN-γ expressions in CD3+CD8- lymphocytes, showed no obvious Th1/Th2 imbalance, while IFN-γ was expressed much more frequently in CD3+CD8+ lymphocytes. Systematically, RSV-infected and bronchiolitis infants showed much lower levels of serum IL-4 and IL-4/IFN-γ ratios and much higher serum IFN-γ levels than control. However, there were no statistical differences in the above three indices between RSV-infected and not-RSV infected infants or between bronchiolitis and pneumonia infants, except that bronchiolitis infants had a higher level of serum IFN-γ than pneumonia infants statistically. Conclusions: There is no type-2 cytokine response predominance in the acute phase of RSV infection and bronchiolitis. IL-4 production is suppressed and IFN-γ production upregulated, the latter being most prominent in bronchiolitis infants.     

An integrated DBP for streams with (<Emphasis Type="Italic">m,k</Emphasis>)-firm real-time guarantee

(m,k)-firm real-time or weakly hard real-time (WHRT) guarantee is becoming attractive as it closes the gap between hard and soft (or probabilistic) real-time guarantee, and enables finer granularity of real-time QoS through adjustingm andk. For multiple streams with (m, k)-firm constraint sharing a single server, an, on-line priority assignment policy based on the most recentk-length history of each stream called distance based priority (DBP) has been proposed to assign priority. In case of priority equality among these head-of-queue instances, Earliest Deadline First (EDF) is used. Under the context of WHRT schedule theory, DBP is the most popular, gets much attention and has many applications due to its straightforward priority assignment policy and easy implementation. However, DBP combined with EDF cannot always provide good performance, mainly because the initial, DBP does not underline the rich information on deadline met/missed distribution, specially streams in various failure states which will travel different distances to restore success states. Considering how to effectively restore the success state of each individual stream from a failure state, an integrated DBP utilizing deadline met/missed distribution is proposed in this paper. Simulation results validated the performance improvement of this proposal. Project supported by the National Natural Science Foundation of China (No.60203030) and Advanced Research Program of France-China (Nos. PRA S101-04, PRA S103-02)     

Targeting of human aFGF gene into silkworm,<Emphasis Type="Italic">Bombyx mori</Emphasis> L. through homologous recombination

The long-arm and short-arm genes of fibroin light chain (L-chain) of silkworm,Bombyx Mori L., and the gene of human acidic fibroblast growth factor were cloned respectively and subsequently inserted into a transfer vector pVL 1392 used as a tool to target the L-chain region of the silkworm genome. Genomic DNA from their offsprings was extracted and the expected targeting was detected using polymerase chain reaction and DNA sequencing, as well as protein analysis. The results showed that positive events occurred and that the FGF gene was integrated into the L-chain locus through homologous recombination. Project supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars, Education Ministry of China and the Natural Science Foundation of Zhejiang Province (No. 301306), China     

“Above must be above,and below must be below”: enactment of relational school leadership in Vietnam

Over the past 20 years, relational theories of leadership have gained increased traction in the global discourse in educational leadership. This is observable in the increased frequency with which scholars have begun to construct leadership within the sociocultural and institutional systems of different societies. This study addressed the question, “How is effective school leadership constructed in the multi-faceted education context of modern day Vietnam?” We employed a multi-site case study research design to collect qualitative data from several stakeholder groups in three Vietnamese schools. Analysis centered on describing and synthesizing how principal leadership was constructed in these settings. This study “contextualized school leadership” by describing how leadership themes of managing relationships, preserving harmony, and teacher empowerment were shaped by institutional, political and socio-cultural forces in Vietnamese society. The findings support the importance of contextualizing leadership in order to understand differences in how “effective school leadership” is constructed and understood across different societies.     

Using Research-Based Video-cases to Help Pre-service Primary Teachers Conceptualize a Contemporary View of Mathematics Teaching

The study inquired into the effect of research-based video-cases on pre-service teachers conceptualizing their understanding of contemporary mathematics teaching. The 43 participants enrolled in a Mathematics Method Course viewed and discussed 5 video-cases of primary teachers teaching. Journal entries, lesson plans, and microteaching observations were collected as data on which the following assertions were based. Pre-service teachers' responses to the 5 videos were more concerned with pedagogical content knowledge than mathematical content and students' learning. They refocused and deepened their awareness of students' learning and questioning skills through discussing the videos. The video-cases improved their construction of pedagogical representation and their ability to identify a problematic situation with multiple perspectives. These effects appeared to be influenced by the scaffold of three factors: vicarious experience to complement personal experience, watching and discussing video-cases enriched by the developers, and journal writing to foster deeper reflections.