Streptomycin inhibits electrophysiological changes induced by stretching of chronically infarcted rat hearts

Objective

To investigate stretch-induced electrophysiological changes in chronically infarcted hearts and the effect of streptomycin (SM) on these changes in vivo.

Methods

Sixty Wistar rats were divided randomly into four groups: a control group (n=15), an SM group (n=15), a myocardial infarction (MI) group (n=15), and an MI+SM group (n=15). Chronic MI was obtained by ligating the left anterior descending branch (LAD) of rat hearts for eight weeks. The in vivo blockade of stretch-activated ion channels (SACs) was achieved by intramuscular injection of SM (180 mg/(kg·d)) for seven days after operation. The hearts were stretched for 5 s by occlusion of the aortic arch. Suction electrodes were placed on the anterior wall of left ventricle to record the monophasic action potential (MAP). The effect of stretching was examined by assessing the 90% monophasic action potential duration (MAPD₉₀), premature ventricular beats (PVBs), and ventricular tachycardia (VT).

Results

The MAPD₉₀ decreased during stretching in both the control (from (50.27±5.61) ms to (46.27±4.51) ms, P<0.05) and MI groups (from (65.47±6.38) ms to (57.47±5.76 ms), P<0.01). SM inhibited the decrease in MAPD₉₀ during inflation ((46.27±4.51) ms vs. (49.53±3.52) ms, P<0.05 in normal hearts; (57.47±5.76) ms vs. (61.87±5.33) ms, P<0.05 in MI hearts). The occurrence of PVBs and VT in the MI group increased compared with that in the control group (PVB: 7.93±1.66 vs. 1.80±0.86, P<0.01; VT: 7 vs. 1, P<0.05). SM decreased the occurrence of PVBs in both normal and MI hearts (0.93±0.59 vs. 1.80±0.86 in normal hearts, P<0.05; 5.40±1.18 vs. 7.93±1.66 in MI hearts, P<0.01).

Conclusions

Stretch-induced MAPD₉₀ changes and arrhythmias were observed in chronically infarcted myocardium. The use of SM in vivo decreased the incidence of PVBs but not of VT. This suggests that SACs may be involved in mechanoelectric feedback (MEF), but that there might be other mechanisms involved in causing VT in chronic MI.     

Mothers’ trust toward teachers in relation to teaching practices

This study examined the extent to which mothers’ trust toward the classroom teacher of their child in first grade is related to observed teaching practices in Finland and Estonia. Sixty-six teachers (32 in Finland, 34 in Estonia) were observed using the Early Childhood Classroom Observation Measure (ECCOM; Stipek & Byler, 2004). Mothers in Finland (n = 266) and in Estonia (n = 348) filled in questionnaires measuring their trust in their child's first grade teacher. The connection between mothers’ education, child gender, and classroom size in relation to mothers’ trust was also investigated. The results of multilevel modeling showed that mothers in both countries trusted more in teachers who were characterized by a higher level of child-centered teaching practices than teacher-directed teaching practices. Furthermore, Estonian mothers showed greater trust in more experienced teachers. The results emphasize the importance of teaching practices in promoting mothers’ trust in their child's teacher.     

A science need: Designing tasks to engage students in modeling complex data

In this information age, the capacity to perceive structure in data, model that structure, and make decisions regarding its implications is rapidly becoming the most important of the quantitative literacy skills. We build on Kaput’s belief in a Science of Need to motivate and direct the development of tasks and tools for engaging students in reasoning about data. A Science of Need embodies the utility value of mathematics, and engages students in seeing the importance of mathematics in both their current and their future lives. An extended example of the design of tasks that require students to generate, test, and revise models of complex data is used to illustrate the ways in which attention to the contributions of students can aid in the development of both useful and theoretically coherent models of mathematical understanding by researchers. Tools such as Fathom are shown as democratizing agents in making data modeling more expressive and intimate, aiding in the development of deeper and more applicable mathematical understanding.

On semiotics and subjectivity: a response to Tony Brown’s “signifying ‘students’, ‘teachers’, and ‘mathematics’: a reading of a special issue”

In this response we address some of the significant issues that Tony Brown raised in his analysis and critique of the Special Issue of Educational Studies in Mathematics on “Semiotic perspectives in mathematics education” (Sáenz-Ludlow & Presmeg, Educational Studies in Mathematics 61(1–2), 2006). Among these issues are conceptualizations of subjectivity and the notion that particular readings of Peircean and Vygotskian semiotics may limit the ways that authors define key actors or elements in mathematics education, namely students, teachers and the nature of mathematics. To deepen the conversation, we comment on Brown’s approach and explore the theoretical apparatus of Jacques Lacan that informs Brown’s discourse. We show some of the intrinsic limitations of the Lacanian idea of subjectivity that permeates Brown’s insightful analysis and conclude with a suggestion about some possible lines of research in mathematics education.

Effects of playing mathematics computer games on primary school students’ multiplicative reasoning ability

This study used a large-scale cluster randomized longitudinal experiment (N = 719; 35 schools) to investigate the effects of online mathematics mini-games on primary school students’ multiplicative reasoning ability. The experiment included four conditions: playing at school, integrated in a lesson (E_school), playing at home without attention at school (E_home), playing at home with debriefing at school (E_home-school) and, in the control group, playing at school mini-games on other mathematics topics (C). The mini-games were played in Grade 2 and Grade 3 (32 mini-games in total). Using tests at the end of each grade, effects on three aspects of multiplicative reasoning ability were measured: knowledge of multiplicative number facts, skills in multiplicative operations, and insight in multiplicative number relations and properties of multiplicative operations. Through path analyses it was found that the mini-games were most effective in the E_home-school condition, where both students’ skills and their insight were positively affected as compared to the control group (significant ds ranging from 0.22 to 0.29). In the E_school condition, an effect was only found for insight in Grade 2 (d = 0.35), while in the E_home condition no significant effects were found. Students’ gameplay behavior (time and effort put in the games) was in some cases, but not always, related to their learning outcomes.     

Fourth Graders' Social Standing with Peers: A Prospective Study on the Role of First Grade Physical Activity,Weight Status,and Motor Proficiency

We prospectively examined the role of physical activity involvement, weight status, and motor functioning capability in 1^st grade for social status among other pupils in class in the 4^th grade. Our sample included 80 Norwegian 1^st grade pupils (Girls N = 44; Boys N = 36). 1^st grade motor proficiency and objectively measured physical activity, but not weight status was predictive of 4^th grade social standing among pupils in class as measured by socio‐metric status. Interaction findings also revealed that 1^st grade healthy weight children being proficient in the motor domain benefit more in terms of their social standing among peers in 4^th grade than do 1^st grade overweight but equally motor proficient children. Being physically active in the 1^st grade seems more important for social standing among peers in 4^th grade for 1^st grade girls than for boys. Results may inform early intervention efforts in school to enhance pupils' psychosocial development.     

Comparing video and virtual reality as tools for fostering interest and self-efficacy in classroom management: Results of a pre-registered experiment

Video is a widely used medium in teacher training for situating student teachers in classroom scenarios. Although the emerging technology of virtual reality (VR) provides similar, and arguably more powerful, capabilities for immersing teachers in lifelike situations, its benefits and risks relative to video formats have received little attention in the research to date. The current study used a randomized pretest–posttest experimental design to examine the influence of a video- versus VR-based task on changing situational interest and self-efficacy in classroom management. Results from 49 student teachers revealed that the VR simulation led to higher increments in self-reported triggered interest and self-efficacy in classroom management, but also invoked higher extraneous cognitive load than a video viewing task. We discussed the implications of these results for pre-service teacher education and the design of VR environments for professional training purposes.

Practitioner notes

What is already known about this topic

• Video is a popular teacher training medium given its ability to display classroom situations.
• Virtual reality (VR) also immerses users in lifelike situations and has gained popularity in recent years.
• Situational interest and self-efficacy in classroom management is vital for student teachers' professional development.

What this paper adds

• VR outperforms video in promoting student teachers' triggered interest in classroom management.
• Student teachers felt more efficacious in classroom management after participating in VR.
• VR also invoked higher extraneous cognitive load than the video.

Implications for practice and/or policy

• VR provides an authentic teacher training environment for classroom management.
• The design of the VR training environment needs to ensure a low extraneous cognitive load.

     

Child maltreatment among boy and girl probationers: Does type of maltreatment make a difference in offending behavior and psychosocial problems?

This study examined differences in offending behavior and psychosocial problems between juvenile offenders who have been sexually abused (n = 231), physically abused (n = 1,568), neglected (n = 1,555), exposed to multiple forms of maltreatment (n = 1,767), and non-victims (n = 8,492). In addition, the moderating effect of gender in the association between type of maltreatment and offending behavior/psychosocial problems was examined. Results showed that violent offenses were more common in victims of physical abuse and victims of multiple forms of abuse than in non-victims, both in boys and girls. In boys, sexual offenses were far more common in victims of sexual abuse than in victims of other or multiple forms of maltreatment or in non-victims. In girls, no group differences were found in sexual offending behavior. For both boys and girls, externalizing problems were relatively common in victims of physical abuse and neglect whereas internalizing problems were relatively common in victims of sexual abuse. In victims of multiple forms of maltreatment, both internalizing and externalizing problems were relatively common. Implications for clinical practice are discussed.     

Successful Programs for Undergraduate Women in Science and Engineering: Adapting versus Adopting the Institutional Environment

This article focuses upon programs for undergraduate women in science and engineering, which are a strategic research site in the study of gender, science, and higher education. The design involves both quantitative and qualitative approaches, linking theory, method, questions, and analyses in ways not undertaken previously. Using a comprehensive, quantitative, cross-institutional, and longitudinal method, two extreme groups of programs are distinguished: those associated with the “most successful” and “least successful” outcomes in undergraduate degrees awarded to women in science and engineering. Qualitative analyses of interview data with key players in the programs in these two groups point to ways in which definitions of issues, problems, and solutions diverge (as well as converge), and thus to conceptual underpinnings that have important real-life consequences in these organizational settings of higher education. The programs that regard issues, problems, and solutions of women in science and engineering as rooted in “institutional/structural-centered,” as opposed to “individual/student-centered,” perspectives are associated with the most positive outcomes in undergraduate degrees awarded to women in science and engineering.

Māori science education in Aotearoa New Zealand

Abstract    This article reports on the first two phases of a multiphase science education development project in predominantly Māori kura (school communities) in the central region of the North Island of Aotearoa New Zealand. The development project in its entirety employs an action research methodology and by so doing endeavors to support the improvement of science education delivery in accordance with school community aspirations. The full project (a) establishes the current situation in Year 1–8 science education in the communities; (b) identifies developmental aspirations for stakeholders within the communities and identifies potential contributors and constraints to these aspirations; (c) implements mechanisms for achieving identified aspirations; and finally; (d) evaluates the effectiveness of such mechanisms. In its focus on the first two phases, this article incorporates the analytical lenses of Kaupapa Māori Theory and Bronfenbrenner’s bio-ecological model. It concludes by outlining some priorities to consider for science education development based on the outcomes of our preliminary discussions.

Does spatial awareness training affect anatomy learning in medical students?

Spatial ability (SA) is the cognitive capacity to understand and mentally manipulate concepts of objects, remembering relationships among their parts and those of their surroundings. Spatial ability provides a learning advantage in science and may be useful in anatomy and technical skills in health care. This study aimed to assess the relationship between SA and anatomy scores in first- and second-year medical students. The training sessions focused on the analysis of the spatial component of objects' structure and their interaction as applied to medicine; SA was tested using the Visualization of Rotation (ROT) test. The intervention group (n = 29) received training and their pre- and post-training scores for the SA tests were compared to a control group (n = 75). Both groups improved their mean scores in the follow-up SA test (P < 0.010). There was no significant difference in SA scores between the groups for either SA test (P = 0.31, P = 0.90). The SA scores for female students were significantly lower than for male students, both at baseline and follow-up (P < 0.010). Anatomy training and assessment were administered by the anatomy department of the medical school, and examination scores were not significantly different between the two groups post-intervention (P = 0.33). However, participants with scores in the bottom quartile for SA performed worse in the anatomy questions (P < 0.001). Spatial awareness training did not improve SA or anatomy scores; however, SA may identify students who may benefit from additional academic support.     

Changing schooling,changing shadow: shapes and functions of juku in Japan

Private supplementary tutoring became a widespread phenomenon in Japan during the 1960s. Since then, institutions providing tutoring known as juku have provided a wide range of services to supplement mainstream education. During decades of development, the shapes and functions of juku have changed in response to changes in schooling. Government attitudes towards juku have also shifted from rejection to collaboration, partly because juku have become so entrenched in Japanese society and can no longer be excluded from public decision-making processes. Collaboration between schools and juku is becoming increasingly evident in a series of neoliberal policy choices and socio-demographic changes. Patterns underline a government move to mobilize profit-driven juku to serve the public good. The inclusion of juku in public schooling necessitates reconceptualization of the roles of juku in the educational landscape. This article presents a conceptual framework based on an overview of the changing relationships between juku and schooling. It also identifies challenges in the collaboration, and explores implications for future relationships between mainstream and shadow education.     

Exploring gender roles’ effects of Turkish women teachers on their teaching practices

The purpose of this study is to investigate how gender roles of women teachers affect their practices in the classrooms. Participants in the study were 75 female teachers working in elementary schools in Adana, Turkey. Findings indicated that gender roles of women teachers have important effects on their educational practices. Women teachers explained how their gender roles affect their profession mostly in terms of “also being a mother” in both positive and negative directions. The main points in teachers’ explanations were “being a mother and a spouse”, “stress”, “close relationships with students and parents” and “lack of authority and issues of confidence”.     

Integrating Undergraduate Peer Mentors into Liberal Arts Courses: A Pilot Study

This article presents research and narratives on the integration of course-based peer learning assistants into seven courses. A new curricular peer mentoring program was piloted in the 2005–2006 academic year in an interdisciplinary liberal arts college at a large Canadian research university. Undergraduate students enrolled in a practicum course which supported their learning while they collaborated with the “host instructor” of the course in which they served as peer mentor. Assistants’ roles varied and included individual tutoring, help via email, online discussion facilitation, small group facilitation, in-class presentation and discussion facilitation, and extracurricular study groups. Their integration into scheduled class activities resulted in participating students’ perception of enhanced learning. Data included peer mentors’ assignments, host instructor feedback, and student surveys.

Technology addiction,abduction and adoption in higher education: Bird's eye view of the ICT4AD policy in Ghana 20 years on

Twenty years after its inauguration, the information communication and technology for accelerated development (ICT4AD) policy intended to transform Ghana into an information and technology-driven high-income economy through digital education has been unsuccessful. In this digital era, young adults' attachment to technological tools is anticipated to expedite technological adoption in the education sector. Still, there are less promising indicators of realizing this expectation because of situational factors that curtail technology usage and adoption in higher education (HE). It is estimated that the adoption of technology in HE will aid Ghana in using ICT as its engine of growth. This paper gauges the progress of the ICT4AD policy after two decades, presents an intricate account of why technology integration in HE in Ghana is still in its infancy and proposes interventions for sustaining and advancing the objectives of the ICT4AD policy. Drawing from an extensive review of literature on three conceptualized thematic themes relating to technology (ie, addiction, abduction and adoption), policymakers in education and stakeholders in HE will be able to identify their roles in guaranteeing the success of the promulgated ICT4AD policy. Viable areas of research are also discussed in the study.

Practitioner notes

What is already known about this topic?

• The promulgated information communication and technology for accelerated development (ICT4AD) policy of Ghana hopes to transform the country into a technology-driven economy.
• Technology integration in education and society is still in its infancy in Ghana in this information age.

What this paper adds?

• It gauges the progress of the ICT4AD policy and presents an intricate account of why technology integration in HE in Ghana is still in its infancy and proposes interventions for sustaining and advancing the objectives of the ICT4AD policy.
• It sounds the alarm that the ICT4AD policy is at its terminal stage and calls on policymakers in education to revisit and revise the policy.
• It identifies the main factors curtailing effective technology integration in Ghana.
• It suggests promising steps for Ghana to adopt technology as its engine of growth.

Implications of this study for practice and/or policy

• It provides information to education practitioners and relevant school stakeholders on how to effectively adopt technology to develop 21st-century skills among learners.
• It explores the potential channels for policymakers in education to revisit and reinvest in the ICT4AD policy for the successful attainment of the policy objectives.
• It calls on countries with similar contexts like Ghana to adopt a multifaceted approach to drive ICT initiatives.

     

Very long-term retention of the control of variables strategy following a brief intervention

Middle school students (n = 354) were tested for their understanding of the control of variables strategy (CVS) 2.5 years after participating in a study comparing three different interventions for teaching CVS. The key finding was that the pattern of effects observed in the 4^th grade continued to be observed in the 6^th grade. This was because (a) students who had mastered CVS in the 4^th grade were likely to continue to perform at mastery levels in the 6^th grade whereas (b) the learning of students who had not mastered CVS in 4^th grade was independent of the teaching intervention they had received in the 4^th-grade study. These findings demonstrate that a brief intervention of direct instruction in CVS can produce long-lasting learning of the principle of controlling variables.     

Study on the serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in patients withHelicobacter pylori infection

Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) andHelicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulcer. Methods: The serum levels of sICAM-1 in 205 patients with chronic gastric diseases were detected by ELISA method and the status ofH. pylori was determined by histologic examination, RUT,¹⁴C-UBT, and serology. The sera obtained from 18 healthy volunteers served as controls. Results: The serum levels of sICAM-1 were significantly higher in patients withH. pylori positive than those of H. pylori negative (889.43±32.52 ng/ml vs. 747.07±30.45 ng/ml,P<0.05). The serum levels of sICAM-1 in patients with mild, moderate and severe infection ofH. pylori were 841.68±72.36 ng/ml, 905.43±37.59 ng/ml and 1012.54±49.34 ng/ml, respectively (P<0.05). The serum levels of sICAM-1, proved to be significantly correlated with the density ofH. pylori colonization in gastric mucosa (r _s=0.316,P<0.001). The serum levels of sICAM-1 in patients with chronic gastritis and peptic ulcer were significantly higher than those in healthy controls (P<0.05). Conclusions: These results indicated thatH. pylori infection up-regulates the expression of sICAM-1.     

Negotiating identity and science teaching in a high-stakes testing environment: an elementary teacher’s perceptions

This study draws upon a qualitative case study to investigate the impact of the high-stakes test environment on an elementary teacher’s identities and the influence of identity maintenance on science teaching. Drawing from social identity theory, I argue that we can gain deep insight into how and why urban elementary science teachers engage in defining and negotiating their identities in practice. In addition, we can further understand how and why science teachers of poor urban students engage in teaching decisions that accommodate school demands and students’ needs to succeed in high-stakes tests. This paper presents in-depth experiences of one elementary teacher as she negotiates her identities and teaching science in school settings that emphasize high-stakes testing. I found that a teacher’s identities generate tensions while teaching science when: (a) schools prioritize high-stakes tests as the benchmark of teacher success and student success; (b) activity-based and participatory science teaching is deemphasized; (c) science teacher of minority students identity is threatened or questioned; and (d) a teacher perceives a threat to one’s identities in the context of high stakes testing. Further, the results suggest that stronger links to identities generate more positive values in teachers, and greater possibilities for positive actions in science classrooms that support minority students’ success in science.