Upper secondary students’ thinking pathways in cell membrane biology–an evidence-based development and evaluation of learning activities using the Model of Educational Reconstruction

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Content-Based and Cognitive-Linguistic Analysis of Cell Membrane Biology: Educational Reconstruction of Scientific Conceptions

By means of their pivotal role in the outbreak of a variety of diseases, such as, recently, COVID-19, the molecular aspects of cell membrane function have gained considerable attention from researchers in recent decades. The resulting information explosion and the growing interdisciplinary character of cell biology seems, however, to not be represented in science classrooms. Hence, there appears to be a gap between what is scientifically known and what is actually taught in classrooms. Framed by the model of educational reconstruction (MER), the aim of our study is therefore to identify scientific core ideas of cell membrane biology from an educational point of view. This is achieved by conducting qualitative content analysis of relevant cell biology literature. By using Conceptual Metaphor as a theory of understanding, we additionally illuminate the experiential grounding of scientific conceptions. Our results propose that cell membrane biology can be structured into three core ideas, comprising compartmentalisation, physical and chemical properties, and multicellular coordination interrelated by evolution as a key aspect. Our results show that scientists conceive these ideas metaphorically. Embodied part-whole relations seem, for example, to lay the grounds for their understanding of biological function. The outcomes of the study may inform future cell membrane teaching

Content-based and cognitive-linguistic analysis of cell membrane biology: Educational reconstruction of scientific conceptions

By means of their pivotal role in the outbreak of a variety of diseases, such as, recently, COVID-19, the molecular aspects of cell membrane function have gained considerable attention from researchers in recent decades. The resulting information explosion and the growing interdisciplinary character of cell biology seems, however, to not be represented in science classrooms. Hence, there appears to be a gap between what is scientifically known and what is actually taught in classrooms. Framed by the model of educational reconstruction (MER), the aim of our study is therefore to identify scientific core ideas of cell membrane biology from an educational point of view. This is achieved by conducting qualitative content analysis of relevant cell biology literature. By using Conceptual Metaphor as a theory of understanding, we additionally illuminate the experiential grounding of scientific conceptions. Our results propose that cell membrane biology can be structured into three core ideas, comprising compartmentalisation, physical and chemical properties, and multicellular coordination interrelated by evolution as a key aspect. Our results show that scientists conceive these ideas metaphorically. Embodied part-whole relations seem, for example, to lay the grounds for their understanding of biological function. The outcomes of the study may inform future cell membrane teachin

Pulsed EPR spectroscopy distance measurements of DNA internally labelled with Gd³⁺-DOTA

Gd3+ is increasingly used in EPR spectroscopy due to its increased intracellular stability and signal-to-noise ratios. Here we present the incorporation of Gd3+-DOTA into internal positions in DNA. Distance measurements via pulsed Electron Paramagnetic Resonance (EPR) spectroscopy in vitro and in cellula proved enhanced stability and efficiency compared to nitroxide labels.publishe

A bacterial DNA quadruplex with exceptional K⁺ selectivity and unique structural polymorphism

The G-rich sequence d[(G4CT)3G4] was recently identified as a potential quadruplex-forming sequence associated with loci involved in antigenic variation in the human pathogen Treponema pallidum. We found this motif to be enriched in eubacterial genomes. Employing a combination of CD spectroscopy, EPR spectroscopy, analytical ultracentrifugation, and EMSA, we demonstrate that d[(G4CT)3G4] displays unique features among the many G-quadruplex-forming sequences studied so far. To our knowledge d[(G4CT)3G4] shows a so far unprecedented selectivity for K+ with even high concentrations of Na+ unable to induce pronounced G-quadruplex formation. A remarkable continuous and complete transition from an anti-parallel, monomolecular structure into a tetrameric, parallel conformation is observed upon increasing K+-concentrations. Furthermore we investigate the effects of cation selectivity, quadruplex loop composition and length as well as G-tract length on quadruplex conversion

Occupational prestige, social mobility and the association with lung cancer in men

$\bf Background:$ The nature of the association between occupational social prestige, social mobility, and risk of lung cancer remains uncertain. Using data from the international pooled SYNERGY case–control study, we studied the association between lung cancer and the level of time-weighted average occupational social prestige as well as its lifetime trajectory. $\bf Methods:$ We included 11,433 male cases and 14,147 male control subjects. Each job was translated into an occupational social prestige score by applying Treiman’s Standard International Occupational Prestige Scale (SIOPS). SIOPS scores were categorized as low, medium, and high prestige (reference). We calculated odds ratios (OR) with 95 % confidence intervals (CI), adjusting for study center, age, smoking, ever employment in a job with known lung carcinogen exposure, and education. Trajectories in SIOPS categories from first to last and first to longest job were defined as consistent, downward, or upward. We conducted several subgroup and sensitivity analyses to assess the robustness of our results. $\bf Results:$ We observed increased lung cancer risk estimates for men with medium (OR = 1.23; 95 % CI 1.13–1.33) and low occupational prestige (OR = 1.44; 95 % CI 1.32–1.57). Although adjustment for smoking and education reduced the associations between occupational prestige and lung cancer, they did not explain the association entirely. Traditional occupational exposures reduced the associations only slightly. We observed small associations with downward prestige trajectories, with ORs of 1.13, 95 % CI 0.88–1.46 for high to low, and 1.24; 95 % CI 1.08–1.41 for medium to low trajectories. $\bf Conclusions:$ Our results indicate that occupational prestige is independently associated with lung cancer among men

The syndrome of hemophagocytic lymphohistiocytosis in primary immunodeficiencies: implications for differential diagnosis and pathogenesis

Hemophagocytic lymphohistiocytosis is a hyperinflammatory syndrome defined by clinical and laboratory criteria. Current criteria were created to identify patients with familial hemophagocytic lmyphohistiocytosis in immediate need of immunosuppressive therapy. However, these criteria also identify patients with infection-associated hemophagocytic inflammatory states lacking genetic defects typically predisposing to hemophagocytic lymphohistiocytosis. These patients include those with primary immunodeficiencies, in whom the pathogenesis of the inflammatory syndrome may be distinctive and aggressive immunosuppression is contraindicated. To better characterize hemophagocytic inflammation associated with immunodeficiencies, we combined an international survey with a literature search and identified 63 patients with primary immunodeficiencies other than cytotoxicity defects or X-linked lymphoproliferative disorders, presenting with conditions fulfilling current criteria for hemophagocytic lymphohistiocytosis. Twelve patients had severe combined immunodeficiency with <100/μL T cells, 18 had partial T-cell deficiencies; episodes of hemophagocytic lymphohistiocytosis were mostly associated with viral infections. Twenty-two patients had chronic granulomatous disease with hemophagocytic episodes mainly associated with bacterial infections. Compared to patients with cytotoxicity defects, patients with T-cell deficiencies had lower levels of soluble CD25 and higher ferritin concentrations. Other criteria for hemophagocytoc lymphohistiocytosis were not discriminative. Thus: (i) a hemophagocytic inflammatory syndrome fulfilling criteria for hemophagocytic lymphohistiocytosis can be the initial manifestation of primary immunodeficiencies; (ii) this syndrome can develop despite severe deficiency of T and NK cells, implying that the pathophysiology is distinct and not appropriately described as "lympho"-histiocytosis in these patients; and (iii) current criteria for hemophagocytoc lymphohistiocytosis are insufficient to differentiate hemophagocytic inflammatory syndromes with different pathogeneses. This is important because of implications for therapy, in particular for protocols targeting T cells

Les politiques d'innovation coopérative en Allemagne et en France

L'innovation se situe au cœur des stratégies économiques contemporaines. Dans un contexte de changements profonds et accélérés par la mondialisation et l'émergence de nouveaux concurrents, par les mutations technologiques et les perspectives ouvertes par l'économie de la connaissance, enfin par les problèmes écologiques et les défis du développement durable, les économies européennes ont un besoin impérieux de développer leur capacité d'innovation pour faire face à ces défis multiples. Il y va de leur compétitivité, du maintien de leur potentiel d'emploi et de croissance et, au-delà, de leur capacité de préserver, tout en les adaptant, leurs modèles économiques et sociaux. L'Allemagne s'attache depuis bientôt deux décennies à promouvoir une modernisation systémique de son dispositif de recherche et d'innovation, non seulement en y consacrant des moyens accrus, articulés autour d'axes stratégiques significatifs, mais également en mettant en œuvre de nouvelles régulations entre pouvoirs publics, recherche, milieux professionnels et entreprises. Le pays privilégie ainsi une politique d'innovation coopérative, fondée sur des réseaux de coopération entre les acteurs (réseaux de compétences, clusters, coopérations interentreprises intégrant les PME). Dans une démarche parallèle, la France se concentre principalement, depuis 2004, sur la mise en place et la promotion des pôles de compétitivité. Face au défi actuel de la mise en commun des potentiels d'innovation nationaux à l'échelle européenne, le benchmark France-Allemagne constitue un point de passage obligé pour comprendre et concilier les dynamiques d'innovation respectives, renforcer les coopérations et impulser les synergies franco-allemandes qui contribueront à la compétitivité globale de l'UE. Au regard de cet enjeu décisif, le présent ouvrage se propose de rendre compte des orientations et des démarches mises en œuvre dans le cadre de la politique allemande d'innovation et de les mettre en regard avec celles développées en France. La concertation franco-allemande en matière d'innovation ne peut pas être uniquement le fait des décideurs politiques nationaux, mais doit impliquer également davantage les acteurs scientifiques, économiques et territoriaux, à l'instar de ce qui se pratique outre-Rhin et constitue le point fort du système allemand de recherche et d'innovation. A travers ce livre, nous avons voulu montrer concrètement, en nous appuyant sur la parole des acteurs, l'intérêt du cas allemand et tracer les voies d'une meilleure convergence entre deux pays partenaires de poids qui devraient s'attacher, mieux qu'ils ne l'ont fait jusqu'à présent, à mettre en commun leurs potentiels considérables de recherche et d'innovation, au profit de la compétitivité et de l'avenir de l'Europe