A technology gap interpretation of growth paths in Asia and Latin America

This paper presents a North-South technology gap model which combines the Schumpeterian approach to technical and structural change with the Keynesian perspective on effective demand and the Balance-of-Payments (BOP) constraint as drivers of growth. Three are the contributions of the paper. First, it develops a model in which the technology gap, relative productivity and relative wages co-evolve and may generate different paths of convergence or divergence between South and North depending on the parameters of the model. Second, the parameters of the model are associated with different types of policies, which allows for discussing how these policies may change the growth path. Finally, the model is used to discuss the contrasting experiences of Asia and Latin America since 1970. Convergence in Asia and divergence in Latin America have been extensively debated topics in the literature on comparative economic development, which highlights the crucial role of industrial policy. It is argued that the results of the technology gap model are consistent with the findings of this literature and helps understand the forces behind convergence and divergence.     

Does moderate-intensity continuous training result in greater total energy expenditure compared to high-intensity interval training?

Recently in the Journal of Sports Sciences, Schaun et al. published a study on the comparison of energy expenditure between high-intensity interval training and moderate continuous training performed in water. With this Letter to the Editor, we would like to comment on the methodological aspects that should be considered to analyze the results presented, as well as the conclusions.

Abbreviations: CONT, moderate-intensity continuous training; EPOC, excess post-exercise oxygen consumption; HIIT, high-intensity interval training; VO2max, maximal oxygen consumption.     

Does engagement in Forest School influence perceptions of risk,held by children,their parents,and their school staff?

In a climate where, it is claimed, children now spend very little time out of doors because adults fear for their safety and impose a ‘zero risk childhood’ on them, Forest School aims to offer learners the opportunity to take ‘supported risks’. This study investigated perceptions of risk associated with the outdoors, held by children, their parents and practitioners, and whether accessing Forest School impacts on these perceptions of risk. Practitioners were generally either strongly risk-averse or strongly permissive; Forest School influenced them to be less risk-averse in some respects. Parents held ambiguous perceptions, wanting to keep their children very safe but also to help them develop strong and confident attitudes to risk. Implications for research and practice are discussed.     

Impacts of contextual and explicit instruction on preservice elementary teachers' understandings of the nature of science

This mixed‐methods investigation compared the relative impacts of instructional approach and context of nature of science instruction on preservice elementary teachers' understandings. The sample consisted of 75 preservice teachers enrolled in four sections of an elementary science methods course. Independent variables included instructional approach to teaching nature of science (implicit vs. explicit) and the context of nature of science instruction (as a stand‐alone topic vs. situated within instruction about global climate change and global warming). These treatments were randomly applied to the four class sections along a 2 × 2 matrix, permitting the comparison of outcomes for each independent variable separately and in combination to those of a control group. Data collection spanned the semester‐long course and included written responses to pre‐ and post‐treatment administrations of the VNOS‐B, semi‐structured interviews, and a variety of classroom artifacts. Qualitative methods were used to analyze the data with the goal of constructing profiles of participants' understandings of the nature of science and of global climate change /global warming (GCC/GW). These profiles were compared across treatments using non‐parametric statistics to assess the relative effectiveness of the four instructional approaches. Results indicated that preservice teachers who experienced explicit instruction about the nature of science made statistically significant gains in their views of nature of science regardless of whether the nature of science instruction was situated within the context of GCC/GW or as a stand‐alone topic. Further, the participants who experienced explicit nature of science instruction as a stand‐alone topic were able to apply their understandings of nature of science appropriately to novel situations and issues. We address the implications of these results for teaching the nature of science in teacher preparation courses. © 2010 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 414–436, 2011     

Listening to grandmothers

In this column, three proud grandmothers share their unique stories and eloquently describe the transforming experience of becoming a grandmother and the joy associated with witnessing their daughters giving birth.     

Does cardiopulmonary resuscitation cause rib fractures in children? A systematic review

BACKGROUND: There is a diagnostic dilemma when a child presents with rib fractures after cardiopulmonary resuscitation (CPR) where child abuse is suspected as the cause of collapse. We have performed a systematic review to establish the evidence base for the following questions: (i) Does cardiopulmonary resuscitation cause rib fractures in children? (ii) If so, what are the frequency and characteristics of these fractures that may help to distinguish them from rib fractures caused by physical abuse? METHODS: We performed a literature search of original articles, references, textbooks, and conference abstracts, published in any language from 1950 to 1 October 2005. Articles were identified from ASSIA, Caredata, Medline, Ovid Medline in Process, ChildData, CINAHL, Embase, ISI Proceedings, SIGLE, Science Citation Index, Social Science Citation Index, and TRIP databases. We included all studies that addressed rib fractures and CPR in children less than 18 years, and excluded review articles, expert opinion, consensus guidelines, and studies that were significantly methodologically flawed on critical appraisal. Each study underwent two independent reviews (with a third review if there was disagreement). Each reviewer used standardized criteria for study definition, data extraction, and critical appraisal, to determine the quality of the study and to establish if it met the inclusion criteria of this systematic review. FINDINGS: Of the 427 studies reviewed, 6 were included: 1 case control, 4 cross-sectional, and 1 case series. These represent data on 923 children who underwent CPR. Three children sustained rib fractures as a result of resuscitation; all three of these had fractures that were anterior (two mid-clavicular and one costo-chondral). We did not find any child in the literature who had a posterior rib fracture due to CPR. Resuscitation was performed variably by both medical and non-medical personnel. CONCLUSION: Rib fractures after cardiopulmonary resuscitation are rare. When they do occur, they are anterior and may be multiple. As the studies performed to date did not use the most sensitive techniques for detecting rib fractures, further prospective studies of children would be valuable to provide additional clarification on this question.     

Using compositional data analysis to explore accumulation of sedentary behavior,physical activity and youth health

Purpose:The study aimed to describe youth time-use compositions,focusing on time spent in shorter and longer bouts of sedentary behavior and physical activity(PA),and to examine associations of these time-use compositions with cardiometabolic biomarkers.Methods:Accelerometer and cardiometabolic biomarker data from 2 Australian studies involving youths 7-13 years old were pooled(complete cases with accelerometry and adiposity marker data,n=782).A 9-component time-use composition was formed using compositional data analysis:time in shorter and longer bouts of sedentary behavior;time in shorter and longer bouts of light-,moderate-,or vigorous-intensity PA;and"other time"(i.e.,non-wear/sleep).Shorter and longer bouts of sedentary time were defined as<5 min and>5 min,respectively.Shorter bouts of light-,moderate-,and vigorous-intensity PA were defined as<1 min;longer bouts were defined as≥1 min.Regression models examined associations between overall time-use composition and cardiometabolic biomarkers.Then,associations were derived between ratios of longer activity patterns relative to shorter activity patterns,and of each intensity level relative to the other intensity levels and"other time",and cardiometabolic biomarkers.Results:Confounder-adjusted models showed that the overall time-use composition was associated with adiposity,blood pressure,lipids,and the summary score.Specifically,more time in longer bouts of light-intensity PA relative to shorter bouts of light-intensity PA was significantly associated with greater body mass index z-score(zBMI)(β=1.79;SE=0.68)and waist circumference(β=18.35,SE=4.78).When each activity intensity was considered relative to all higher intensities and"other time",more time in light-and vigorous-intensity PA,and less time in sedentary behavior and moderate-intensity PA,were associated with lower waist circumference.Conclusion:Accumulating PA,particularly light-intensity PA,in frequent short bursts may be more beneficial for limiting adiposity compared to accumulating the same amount of PA at these intensities in longer bouts.