This paper presents a detailed analysis of the post-lesson reflection, carried out in the context of eight cases of lesson study conducted by teams of Danish, lower secondary prospective teachers and ...their supervisors. The participants, representing different institutions, were all new to the lesson study format. Nevertheless, it is demonstrated how their interaction shape the development of discourse about mathematical learning. The anthropological theory of the didactic is employed as the theoretical approach to analyse the mathematical and primarily didactical praxeologies developed and discussed during the meetings. The study investigates what happens when lesson study, a well-established Japanese “system” for professional teacher development, is transposed to another educational and cultural context, with the aim of enhancing prospective teacher learning during the practicum of a teacher education programme. The findings highlight significant different positions in the discourse during the post-lesson reflection. Specific practice-related knowledge is developed, to the benefit of prospective teachers, educators and researchers alike. This kind of knowledge is of interest and concern to the whole profession of mathematics teachers and the analysis adds to our insight into the potential of lesson study in prospective education as a meeting place where pertinent actors contribute to the expansion and dissemination of shared professional knowledge.
This paper presents a case study of didactic infrastructures to direct Study and Research Paths (SRP) in teacher education within the context of interdisciplinary inquiry. The disciplines of school ...mathematics and school biology, and their didactics, are made to interconnect through the investigation of a generating question concerning the illness diabetes. The resulting interdisciplinary knowledge as evidenced through students written diaries is analysed using the Anthropologic Theory of the Didactic and shows the challenge of combining two disciplines and their didactics at the same time. Two particular forms of didactic infrastructure to guide the self-sustained process of SRP are proposed and scrutinized: Selective picking and Side questions. Selective picking is shown to be a promising, yet indirect, infrastructure to steer the SRP without taking away the desired autonomy of the students. Side questions, initially proposed by Ives Chevallard, are considered in light of the case, and a number of suggestions for their characteristics and use are put forward.
Stent Thrombosis, Myocardial Infarction, and Death After Drug-Eluting and Bare-Metal Stent Coronary Interventions Lisette Okkels Jensen, Michael Mæng, Anne Kaltoft, Per Thayssen, Hans Henrik Tilsted ...Hansen, Morten Bøttcher, Jens Flensted Lassen, Lars Romer Krussel, Klaus Rasmussen, Knud Nøerregaard Hansen, Lars Pedersen, Søren Paaske Johnsen, Henrik Toft Sørensen, Leif Thuesen We compared rates of stent thrombosis (ST), myocardial infarction (MI), death, and target lesion revascularization after implantation of drug-eluting stents (DES) and bare-metal stents (BMS), with population-based medical databases in Denmark. The DES were implanted in 3,548 patients, and BMS were implanted in 8,847 patients. The risk of definite ST was similar in the 2 groups. Very late definite ST (between 12 and 15 months after implantation) occurred more frequently in patients receiving DES. The MI and mortality were similar in the 2 groups. Target lesion revascularization was reduced by 43% in patients treated with DES.
This paper deals with the nature of teaching mathematical thinking and presents a case study of a single Japanese lesson where the characteristics of mathematical thinking and the teaching thereof ...are identified in relation to multiplication. The raison d'être for this teaching is questioned and investigated by looking at how multiplication is described in the curriculum and representative textbook material. It is seen how Japanese teachers are institutionally conditioned to incorporate mathematical thinking in the context of multiplication, something which may appear in contrast to other countries. The lesson is analysed using the notion of praxeologies and didactic co-determination conceptualised in the Anthropological Theory of the Didactic.
•Dialogue during reciprocal peer tutoring reveals development of socio-mathematical norms.•Mathematical and social dialogue supports inclusion.•Quantitative discovery followed by quantitative ...analysis suggests causal relationship.
This paper presents a mixed methods analysis of mathematical and social interaction, when the teacher has performed a devolution of a task to pairs of students in a setting of reciprocal peer tutoring. Using data from the project: SYKL in Math (Systematized Reciprocal Peer Tutoring in Mathematics), we quantify the dialogical content of 28 video recorded peer interactions. Based on the quantitative findings, we have selected two cases to provide a detailed qualitative analysis of how students engage with the milieu of SYKL in the beginning of the project, and towards the end. We see how the roles as tutor and tutee, together with affordances of the milieu, provide and channel feedback through the student dialogue. It is seen how conversational actions interact to change and establish socio-mathematical norms beneficial to the learning of mathematics while engaged in processes of enquiry.
Summary Background In low-risk patients, the zotarolimus-eluting stent has been shown to reduce rates of restenosis without increasing the risk of stent thrombosis. We compared the efficacy and ...safety of the zotarolimus-eluting stent versus the sirolimus-eluting stent in patients with coronary artery disease who were receiving routine clinical care with no direct follow-up. Methods We did a single-blind, all-comer superiority trial in adult patients with chronic stable coronary artery disease or acute coronary syndromes, and at least one target lesion. Patients were treated at one of five percutaneous coronary intervention centres between January, 2006, and August, 2007. Computer-generated block randomisation and a telephone allocation service were used to randomly assign patients to receive the zotarolimus-eluting or the sirolimus-eluting stent. Data for follow-up were obtained from national Danish administrative and health-care registries. The primary endpoint was a composite of major adverse cardiac events within 9 months: cardiac death, myocardial infarction, and target vessel revascularisation. Intention-to-treat analyses were done at 9-month and 18-month follow-up. This trial is registered with ClinicalTrials.gov , number NCT00660478. Findings 1162 patients (1619 lesions) were assigned to receive the zotarolimus-eluting stent, and 1170 patients (1611 lesions) to receive the sirolimus-eluting stent. 67 patients (72 lesions) had stent failure, and six patients were lost to follow-up. All randomly assigned patients were included in analyses at 9-month follow-up; 2200 patients (94%) had completed 18-month follow-up by the time of our assessment. At 9 months, the primary endpoint had occurred in a higher proportion of patients treated with the zotarolimus-eluting stent than in those treated with the sirolimus-eluting stent (72 6% vs 34 3%; HR 2·15, 95% CI 1·43–3·23; p=0·0002). At 18-month follow-up, this difference was sustained (113 10% vs 53 5%; 2·19, 1·58–3·04; p<0·0001). For patients receiving the zotarolimus-eluting stent and those receiving the sirolimus-eluting stent, all cause-mortality was similar at 9-month follow-up (25 2% vs 18 2%; 1·40, 0·76–2·56; p=0·28), but was significantly different at 18-month follow-up (51 4% vs 32 3%; 1·61, 1·03–2·50; p=0·035). Interpretation The sirolimus-eluting stent is superior to the zotarolimus-eluting stent for patients receiving routine clinical care. Funding Cordis and Medtronic.
Coronary angiography is the current standard method to evaluate coronary atherosclerosis in patients with suspected angina pectoris, but non-invasive CT scanning of the coronaries are increasingly ...used for the same purpose. Low-density lipoprotein (LDL) cholesterol and other lipid and lipoprotein variables are major risk factors for coronary artery disease. Small dense LDL particles may be of particular importance, but clinical studies evaluating their predictive value for coronary atherosclerosis are few.
We performed a study of 194 consecutive patients with chest pain, a priori considered of low to intermediate risk for significant coronary stenosis (>50% lumen obstruction) who were referred for elective coronary angiography. Plasma lipids and lipoproteins were measured including the subtype pattern of LDL particles, and all patients were examined by coronary CT scanning before coronary angiography.
The proportion of small dense LDL was a strong univariate predictor of significant coronary artery stenosis evaluated by both methods. After adjustment for age, gender, smoking, and waist circumference only results obtained by traditional coronary angiography remained statistically significant.
Small dense LDL particles may add to risk stratification of patients with suspected angina pectoris.
Patients with diabetes mellitus have worse outcomes after percutaneous coronary intervention than patients without diabetes mellitus. We compared the risk of stent thrombosis, myocardial infarction, ...death, and target lesion revascularization in diabetic and nondiabetic patients after implantation of drug-eluting stents or bare metal stents. In the Western Denmark Heart Registry, 12,347 consecutive patients (1,575 with and 10,772 without diabetes) were identified and followed up for 2 years. The 2-year risk of definite stent thrombosis was 0.52% in patients with diabetes mellitus and 0.71% in nondiabetic patients (adjusted relative risk RR 0.74, 95% confidence interval CI 0.41 to 1.34, p = 0.321). The 2-year risk of myocardial infarction was greater in the diabetic patients (6.9%) than in the nondiabetic patients (3.6%; adjusted RR 1.96, 95% CI 1.58 to 2.43; p <0.001). The all-cause 2-year mortality rate was almost twice as great for the diabetic patients compared to the nondiabetic patients (12.4% vs 6.7%; adjusted RR 1.91, 95% CI 1.63 to 2.23; p <0.001). The 2-year risk of target lesion revascularization was 8.5% in the diabetic patients and 6.8% in the nondiabetic patients (adjusted RR 1.28, 95% CI 1.10 to 1.49; p <0.001). In conclusion, 2 years after drug-eluting stent or bare metal stent implantation, diabetic patients had a greater risk than nondiabetic patients of myocardial infarction and death. Drug-eluting stent treatment reduced the risk of target lesion revascularization compared to bare metal stent treatment, regardless of diabetes status.
This paper takes an institutional perspective on the topic of sustainability in order to analyse how this 'idea' enters science teacher education through an interdisciplinary approach. It shows how ...the development and implementation of a course for Danish pre-service teachers was conditioned and constrained by a complex web of interactions in and among the teaching disciplines of biology, geography and physics/chemistry and among the institutions of school, teacher college and university. The data collected are used to identify influences among the disciplines as well as disciplinary differences, conceptualised through a new reference model that separates the analysis from the usual sustainability dimensions. The findings reveal how sustainability as a teaching topic can be a unifying idea in an interdisciplinary setting. Disciplinary differences evidently impact course planning and implementation significantly, but not exclusively. By elaborating on the interactions between these circumstances, the paper provides insight into the processes of developing interdisciplinary teacher education.
Diabetes is associated with an increased risk of major adverse cardiac events after percutaneous coronary intervention. We compared clinical outcomes in patients with and without diabetes mellitus ...treated with the second-generation Endeavor zotarolimus-eluting stent (ZES) or the first-generation Cypher Select+ sirolimus-eluting stent (SES). We randomized 2,332 patients to treatment with ZESs (n = 1,162, n = 169 diabetics) or SESs (n = 1,170, n = 168 diabetics) and followed them for 18 months. Randomization was stratified by presence/absence of diabetes. The primary end point was major adverse cardiac events defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization. Secondary end points included these individual end points plus all-cause mortality and target lesion revascularization. In diabetic patients, use of ZES compared to SES was associated with an increased risk of major adverse cardiac events (18.3% vs 4.8%, hazard ratio 4.05, 95% confidence interval 1.86 to 8.82), myocardial infarction (4.7% vs 0.6%, hazard ratio 8.09, 95% confidence interval 1.01 to 64.7), target vessel revascularization (14.2% vs 3.0%, hazard ratio 4.99, 95% confidence interval 1.90 to 13.1), and target lesion revascularization (12.4% vs 1.2%, hazard ratio 11.0, 95% confidence interval 2.59 to 47.1). In patients without diabetes differences in absolute risk decrease were smaller but similarly favored SES. In conclusion, implantation of ZESs compared to SESs is associated with a considerable increased risk of adverse events in patients with diabetes at 18-month follow-up.
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