Quel rôle pour l'école dans la transition écologique? Esquisse d'une sociologie politique, environnementale et prospective du curriculum prescrit

The Anthropocene is considered as the current geological epoch, featuring the disturbance of the global ecological system by human activities. It brings the human species face to face with profound and rapid changes of its environment, incomparable to any previous experience. These changes in the global biogeochemical conditions impose the transformation of modern societies towards a new model of political organisation and economical structures. A transformation of such magnitude requires moving out of the paradigm of Modernity, hence away from the western way of relating humanity with the environment, developed during the previous centuries. Schools are involved in the construction of this specific worldview and can therefore contribute to the transformation of society, provided that a significant curriculum change is made. This research suggests a curriculum model engaging schools on the path of an ecological transition, based on the principles of strong sustainability. Developed in the cultural context of French-speaking Switzerland, more specifically in the State of Vaud, this model was compared to the present prescribed curriculum. It was also compared to the discourse of the main stakeholders of regional and local educational policies. The method comprised two steps. The first step consisted of analysing a corpus of official texts from international, federal and cantonal institutions. The second step was devoted to the analysis of data gathered during interviews with members of the Parliament of the State of Vaud and with representatives of the regional coordination body (Conférence intercantonale de l’instruction publique de la Suisse romande et du Tessin, CIIP). This comparative work led to the results that declarations of intent in favour of education for sustainable development mentioned in the official texts become diluted as one moves closer to the cantonal level. Furthermore, decision makers in the State of Vaud have not added any implementation measures when renewing the school system management tools following the adoption of these prescriptions. In order to remedy this situation, a number of proposals are nonetheless possible, which would allow schools to make a contribution to the ecological transition. I therefore suggest pragmatic recommendations based on diverse but potentially reconcilable viewpoints, expressed by the various interviewed policy makers, in the form of wishes for the future of schools. -- L’Anthropocène, époque géologique marquée par la perturbation des grands équilibres écologiques par les activités humaines, confronte l’espèce humaine à des changements profonds et rapides de son milieu, sans commune mesure avec tout ce qu’elle a connu auparavant. Cette modification des conditions biogéochimiques globales impose une transition des sociétés modernes vers un nouveau modèle d’organisation politique et de fonctionnement économique. Une transformation sociétale d’une telle importance requiert de sortir du paradigme de la Modernité, c’est-à-dire du rapport au monde construit en Occident au cours des siècles passés. L’institution scolaire, qui participe à cette construction d’un rapport au monde particulier, peut contribuer à une métamorphose de la société, à condition d’entreprendre une mutation conséquente. Ce travail de recherche propose un modèle possible de curriculum prescrit engageant l’école sur la voie d’une transition écologique fondée sur les principes de la durabilité forte. Construit dans le contexte culturel de la Suisse romande et plus particulièrement du canton de Vaud, ce modèle a été comparé avec le curriculum prescrit en vigueur, ainsi qu’avec le discours des principaux acteurs de la définition des politiques éducatives romandes et vaudoises. Une première étape a consisté à analyser un corpus de textes officiels issus d’institutions internationales, fédérales et cantonales. Puis une seconde étape a été consacrée à l’analyse de données récoltées lors d’entretiens avec des députés du Parlement vaudois et avec des représentants de la Conférence intercantonale de l’instruction publique de la Suisse romande et du Tessin (CIIP). Ce travail de comparaison a abouti au constat que les déclarations d’intention en faveur de l’éducation en vue d’un développement durable contenues dans les textes officiels se diluent au fur et à mesure que l’on se rapproche de l’échelon cantonal. Ces déclarations n’ont en outre pas été suivies d’effets dans la définition des outils du pilotage du système scolaire vaudois. Pour remédier à cette situation, un certain nombre de propositions permettant à l’institution scolaire de tendre vers une contribution à la transition écologique sont néanmoins envisageables. Ces recommandations pragmatiques s’appuient sur les points de vue variés, mais potentiellement conciliables, exprimés sous la forme de souhaits pour le futur de l’école par les différents décideurs politiques interrogés

Theoretical and experimental comparison of lag-based and time-based exponential moving average models of QT hysteresis

Objective: In the electrocardiogram, adaptation of the QT interval to variations in heart rate is not instantaneous. Quantification of this hysteresis phenomenon relies on mathematical models describing the relation between the RR and QT time series. These models reproduce hysteresis through an effective RR interval computed as a linear combination of the history of past RR intervals. This filter depends on a time constant parameter that may be used as a biomarker. Approach: The most common hysteresis model is based on an autoregressive filter with an impulse response that decreases exponentially with the beat number (lag-based model). Recognizing that the QT time series is unevenly spaced, we propose two exponential moving average filters (time-based models) to define the effective RR interval: one with an impulse response that decreases exponentially with time in seconds, and one with a step response that relaxes exponentially with time in seconds. These two filters are neither linear nor time-invariant. Recurrence formulas are derived to enable efficient implementation. Main results: Application to clinical signals recorded during tilt table test, exercise and 24 h Holter demonstrates that the three models perform similarly in terms of goodness-of-fit. When comparing the hysteresis time constant in two conditions with different heart rates, however, the time-based models are shown to reduce the bias on the hysteresis time constant caused by heart rate acceleration and deceleration. Significance: Time-based models should be considered when intergroup differences in both heart rate and QT hysteresis are expected

Preventive fraction of physical fitness on risk factors in cardiac patients: Retrospective epidemiological study

International audienceAIM: To quantify the preventive fraction of physical fitness on the risk factors in patients with cardiovascular diseases (CVDs).METHODS: A total of 249 subjects (205 men and 44 women) suffering from CVD were categorized into four groups, according to their percentage of physical fitness. We calculated the odds ratio to obtain the preventive fraction in order to evaluate the impact of the physical fitness level on the risk factors (i.e. , abdominal obesity, depression, diabetes, dyslipidemia, hypertension, obesity, overweight and smoking).RESULTS: It is observed that a normal physical fitness level is sufficient to induce a preventive action on abdominal obesity (38%), diabetes (12%), hypertension (33%), obesity (12%) and overweight (11%). Also, the preventive fraction increases with the level of physical fitness, in particular for hypertension (36%) and overweight (16%). A high physical fitness level does not necessarily induce a preventive action in most risk factors, excluding depression.CONCLUSION: This is the first study which demonstrates that reaching a normal physical fitness level is enough to induce aprotection for some risk factors, despite having a CVD

Multi-parametric MRI as an indirect evaluation tool of the mechanical properties of in-vitro cardiac tissues

Background: Early detection of heart failure is essential to effectively reduce related mortality. The quantification of the mechanical properties of the myocardium, a primordial indicator of the viability of the cardiac tissue, is a key element in patient's care. Despite an incremental utilization of multi-parametric magnetic resonance imaging (MRI) for cardiac tissue characteristics and function, the link between multi-parametric MRI and the mechanical properties of the heart has not been established. We sought to determine the parametric relationship between the myocardial mechanical properties and the MR parameters. The specific aim was to develop a reproducible evaluative quantitative tool of the mechanical properties of cardiac tissue using multi-parametric MRI associated to principal component analysis. Methods: Samples from porcine hearts were submitted to a multi-parametric MRI acquisition followed by a uniaxial tensile test. Multi linear regressions were performed between dependent (Young's modulus E) and independent (relaxation times T1, T2 and T2*, magnetization transfer ratio MTR, apparent diffusion coefficient ADC and fractional anisotropy FA) variables. A principal component analysis was used to convert the set of possibly correlated variables into a set of linearly uncorrelated variables. Results: Values of 46.1 +/- 12.7 MPa for E, 729 +/- 21 ms for T1, 61 +/- 6 ms for T2, 26 +/- 7 for T2*, 35 +/- 5% for MTRx100, 33.8 +/- 4.7 for FAx10(-2), and 5.85 +/- 0.21 mm(2)/s for ADCx10(-4) were measured. Multi linear regressions showed that only 45% of E can be explained by the MRI parameters. The principal component analysis reduced our seven variables to two principal components with a cumulative variability of 63%, which increased to 80% when considering the third principal component. Conclusions: The proposed multi-parametric MRI protocol associated to principal component analysis is a promising tool for the evaluation of mechanical properties within the left ventricle in the in vitro porcine model. Our in vitro experiments will now allow us focused in vivo testing on healthy and infracted hearts in order to determine useful quantitative MR-based biomarkers

Assessment of mechanical properties of muscles from multi-parametric magnetic resonance imaging

ABSTRACT: We hypothesized that a relationship existed between the mechanical properties and the magnetic resonance imaging (MRI) parameters of muscles, as already demonstrated in cartilaginous tissues. The aim was to develop an indirect evaluation tool of the mechanical properties of degenerated muscles. Leg and arm muscles of adult rabbits were dissected, and tested 12 hours post mortem, in a state of rigor mortis, or 72 hours post mortem, in a state of post-rigor mortis. The tests consisted of a multi-parametric MRI acquisition followed by a uniaxial tensile test until failure. The statistical analysis consisted of multiple linear regressions and principal component analysis. Significant differences existed between the rigor mortis and post-rigor mortis groups for E but not for the MRI parameters. 78%, 60% or 33% of the Young’s modulus could be explained by the MRI parameters in the post-rigor mortis group, rigor mortis group or both groups respectively. These relationships were confirmed by the principal component analysis. The proposed multi-parametric MRI protocol associated to principal component analysis is a promising tool for the indirect evaluation of muscle mechanical properties and should be useful to find biomarkers and predictive factors of the evolution of the pathologies

Case Report of a Remote Ischemic Preconditioning Intervention during Aerobic Exercise in a 44-year-old Amateur Triathlete Male with a History of Acute Myocardial Infarction

International Journal of Exercise Science 13(3): 924-937, 2020. Over the years, exercise has become increasingly important in patients with acute myocardial infarction (AMI). However, AMI patients need to be closely monitored since they maintain cardiovascular disease risks, such as ventricular repolarization abnormalities in electrocardiograms during exercise and rest. A recent study showed the need to focus on the different potential mechanisms and the applicability of remote ischemic preconditioning (RIPC) for cardiac patients engaged in exercise rehabilitation. This is the first case report that explores the effectiveness of an RIPC intervention in a 44-year-old amateur triathlete male with a history of AMI during a moderate (75% of gas exchange threshold) and high (115% of gas exchange threshold) intensity steady-state cycling aerobic exercise. Prior to aerobic exercise, the participant was allocated to either RIPC intervention or CTL (control) with four cycles of five minutes of ischemia followed by five minutes of reperfusion. ECG was continuously recorded during the protocol. These findings showed that RIPC improved participant’s oxygen uptake response and shortened his ventricular repolarization during steady-state aerobic exercises. By measuring the physiological and electrophysical parameters, this case report adds new evidence for the benefits of RIPC. This study also demonstrates the safety of the intervention for cardiac patients in addition to showing that the intervention is not dangerous or harmful. This provides a new approach to cardiac rehabilitation programs. Future studies with cardiac patients are needed to provide a safe, standardized exercise intervention in cardiac rehabilitation

Physical impairments, activity limitations, and participation restrictions of childhood acute lymphoblastic leukemia survivors with and without hip osteonecrosis : a PETALE cohort study

Purpose Long-term musculoskeletal complications represent a growing burden for survivors of childhood acute lymphoblastic leukemia (cALL). This study aimed to describe physical impairments, activity limitations, and participation restrictions in a high-risk subgroup of cALL survivors of the PETALE cohort. Methods This cross-sectional study, using observational data from the PETALE cohort, included a subgroup of survivors who presented high-risk criteria for late effects. Outcomes measures consisted of hip magnetic resonance imaging, maximal isometric muscle strength (MIMS) or torque (MIMT), range of motion (ROM), Near Tandem Balance (NTB), 6-Minute Walk Test (6MWT), Five Time Sit-to-Stand Test (FTSST), and health-related quality of life. Descriptive statistics and regression analyses were performed. Results Survivors (n = 97, 24.2 ± 6.7 years old) showed limited grip strength, FTSST, and NTB performance compared to reference values (p < 0.001). Thirteen participants (14.6%, 18 hips) had hip osteonecrosis (ON) (53.8% male). Higher severity hip ON was found in female survivors (66.7% vs. 22.2%). Survivors with hip ON had reduced hip external rotation ROM compared to those without (p < 0.05). Relationships were found between MIMS and ROM outcomes (r = 0.32, p < 0.01) and with 6MWT (r = 0.39–0.41, p < 0.001). Our multiple linear regression model explained 27.6% of the variance of the 6MWT. Conclusions Survivors in our subgroup had clinically significant physical impairments and activity limitations, and those with hip ON showed worst hip impairment outcomes. Implications for Cancer Survivors These findings emphasize the importance of long-term follow-up including physical therapy assessment to help early identification and management of physical impairments and activity limitations in survivors of cALL

Contributing factors of unmet needs among young adult survivors of childhood acute lymphoblastic leukemia with comorbidities

Purpose: This study aimed to: (1) describe the domains and levels of unmet needs of young adult survivors of childhood acute lymphoblastic leukemia (cALL) with comorbidities, and (2) to explore the factors associated with higher levels of unmet needs. Unmet need was considered as supportive care needs not met. Methods: The most vulnerable cALL survivors from the PETALE study cohort completed the Short-Form Survivor Unmet Needs Survey, the Brief Pain Inventory and the 15D instrument of health-related quality of life. Demographic and clinical information, including comorbidities, were obtained from medical records or self-reporting. The participants' needs and contributing factors to their needs were evaluated using nonparametric tests. Results: Of the 72 participants, 9 (13%) reported moderate/high levels of overall unmet needs. “Worry about earning money” (56%) and “Dealing with feeling tired” (51%) were the most frequent unmet needs (all levels combined). The factors associated significantly with any domain of unmet needs were: having a comorbidity, reporting altered functional health status, high ALL risk status, pain, age (<26 years), and having previously received psychological support. Conclusion: A minority of young adult survivors of cALL with comorbidities interviewed reported moderate/high levels of unmet needs. However, financial concerns and emotional health and relationship are the two domains of greatest need. Survivors with altered health condition are most at risk of experiencing moderate/high levels of unmet needs. If confirmed in larger samples, interventions should target modifiable contributors of unmet needs such as physical health and comfort, fatigue, and emotional health

Effect of pathology type and severity on the distribution of MRI signal intensities within the degenerated nucleus pulposus: application to idiopathic scoliosis and spondylolisthesis

<p>Abstract</p> <p>Background</p> <p>Disc degeneration is characterized by a loss of cellularity, degradation of the extracellular matrix, and, as a result, morphological changes and biomechanical alterations. We hypothesized that the distribution of the MR signal intensity within the nucleus zone of the intervertebral disc was modified according to the pathology and the severity of the pathology. The objective of this study was to propose new parameters characterizing the distribution of the signal intensity within the nucleus zone of lumbar intervertebral discs, and to quantify these changes in patients suffering from spondylolisthesis or idiopathic scoliosis.</p> <p>Methods</p> <p>A retrospective study had been performed on T2-weighted MR images of twenty nine patients suffering from spondylolisthesis and/or scoliosis. The high intensity zone of the nucleus pulposus was semi-automatically detected. The distance "DX" between the center weighted by the signal intensity and the geometrical center was quantified. The sum of the signal intensity on the axis perpendicular to the longitudinal axis of the disc was plotted for each position of the longitudinal axis allowing defining the maximum sum "SM" and its position "PSM".</p> <p>Results</p> <p>"SM" was clearly higher and "PSM" was more shifted for scoliosis than for spondylolisthesis. A two-way analysis of variance showed that the differences observed on "DX" were not attributed to the pathology nor its severity, the differences observed on "SM" were attributed to the pathology but not to its severity, and the differences observed on "PSM" were attributed to both the pathology and its severity.</p> <p>Conclusions</p> <p>The technique proposed in this study showed significant differences in the distribution of the MR signal intensity within the nucleus zone of intervertebral discs due to the pathology and its severity. The dependence of the "PSM" parameter to the severity of the pathology suggests this parameter as a predictive factor of the pathology progression. This new technique should be useful for the early diagnosis of intervertebral disc pathologies as it highlights abnormal patterns in the MRI signal for low severity of the pathology.</p