Editorial: Medien in der Erziehungswissenschaft II

Im Juli 2004 fand in Darmstadt die zweite MEWISS-Tagung («Medien in der Erziehungswissenschaft») statt, organisiert vom Arbeitsbereich «Bildung und Technik» des Instituts für Allgemeine Pädagogik und Berufspädagogik der TU Darmstadt in Zusammenarbeit mit der Kommission Medienpädagogik der Deutschen Gesellschaft für Erziehungswissenschaft. Fortgesetzt wurde damit der 2003 am Duisburg Learning Lab der Universität Duisburg-Essen begonnene Erfahrungs- und Gedankenaustausch zum Einsatz computer- und netzwerkgestützter Medien in der erziehungswissenschaftlichen Hochschullehre. Damit wurde das Ziel verfolgt, die Diskussion in der erziehungswissenschaftlichen Community über Medienfragen im deutschsprachigen Raum anzuregen, den Austausch über entsprechende Aktivitäten zu fördern, zu einer Verbreitung verfügbarer Lösungen beizutragen, Anknüpfungspunkte für die gemeinsame Fortführung entsprechender Aktivitäten zu finden und vorliegende Kompetenzen zu vernetzen. Dem Tagungsziel entsprechend stellten die Autorinnen und Autoren der Beiträge sich insbesondere der Frage, worin der pädagogische Sinn des Einsatzes Neuer Medien in der Hochschullehre liegt und wie die zur Verfügung stehenden medialen Formen und Mittel für eine pädagogisch verantwortete Praxis zur Wirkung gebracht werden können. C. Swertz führt in das Konzept einer «Web-Didaktik» ein, indem er seinen Beitrag selbst webdidaktisch organisiert. W. Sesink und Mitarbeiter zeigen an einem Beispiel aus dem Studienfach Pädagogik an der TU Darmstadt, dass und wie es möglich ist, eine Vorlesung durch Einsatz eines «interaktiven Skripts» so zu transformieren, dass das aktive und diskursive Arbeiten mit den Vorlesungsinhalten erfolgreich angeregt wird. Entlastung von «überflüssiger Präsenzlehre», um Kapazitäten freizusetzen für aktivierende Lehrformen, ist ein an der TU Kaiserslautern im Lehrbereich Berufs- und Wirtschaftspädagogik verfolgter Ansatz, von dem M. Lermen berichtet. Eine «Lern-, Studier- und Forschungswerkstatt» für die Entwicklung eigener Projekte im Bereich innovativen Medieneinsatzes im Unterricht durch Studierende der Medieninformatik und der Lehrämter stellt die Arbeitsgruppe Hendrik Bunke, Sandra Ostermann, Elin-Birgit Berndt von der Universität Bremen vor. Friederike Siller und Stefan Aufenanger berichten von der Entwicklung einer «Lernanwendung» zum «fallbasierten Erwerb medienpädagogischer Kompetenz» in Lehramtsstudiengängen an der Universität Hamburg. Auch mit dieser Ausgabe verbindet sich die Hoffnung, weitere Impulse und Anregungen zum Medieneinsatz in der erziehungswissenschaftlichen Lehre geben zu können

Transformation einer Vorlesung durch E-Learning-Elemente

Die Veranstaltungsform Vorlesung ist vor allem in geistes- und sozialwissenschaftlichen Studienrichtungen umstritten: mangelnde Aktivierung der Studierenden, kaum Dialog und Diskurs, wenig Möglichkeiten zum Feedback. In diesem Beitrag soll an einem Beispiel aus der Lehrpraxis des Studienfachs Pädagogik an der TU Darmstadt gezeigt werden, dass und wie es möglich ist, eine Vorlesung durch Einsatz von E-Learning-Elementen so zu transformieren, dass das aktive und diskursive Arbeiten mit den Vorlesungsinhalten erfolgreich angeregt wird

Calcium Carbonate Suppresses Haem Toxicity Markers without Calcium Phosphate Side Effect on Colon Carcinogenesis

Red meat intake is associated with increased risk of colorectal cancer. We have previously shown that haemin, haemoglobin and red meat promote carcinogen-induced preneoplastic lesions, aberrant crypt foci, in the colon of rats. We have also shown that dietary calcium phosphate inhibits haemin-induced promotion, and normalizes faecal lipoperoxides and cytotoxicity. Unexpectedly, high-calcium phosphate control diet-fed rats had more preneoplastic lesions in the colon than low-calcium control diet-fed rats. The present study was designed to find a calcium supplementation with no adverse effect, by testing several doses and types of calcium salts. One in vitro study and two short-term studies in rats identified calcium carbonate as the most effective calcium salt to bind haem in vitro and to decrease faecal biomarkers previously associated with increased carcinogenesis: faecal water cytotoxicity, thiobarbituric acid reactive substances. A long term carcinogenesis study in dimethylhydrazine-injected rats demonstrated that a diet containing 100 µmol/g calcium carbonate did not promote aberrant crypt foci, in contrast with previously tested calcium phosphate diet. The results suggest that calcium carbonate, and not calcium phosphate, should be used to reduce haem-associated colorectal cancer risk in meat-eaters. They support the concept that the nature of the associated anion to a protective metal ion is important for chemoprevention

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UB – Publicatie

Газоаналитические средства системы контроля утечек хлора на основе электрохимических сенсоров

Созданы и внедряются газоаналитические средства контроля и сигнализации утечек хлора на основе электрохимических сенсоров с улучшенными характеристиками

Gut microbiota facilitates dietary heme-induced epithelial hyperproliferation by opening the mucus barrier in colon

Colorectal cancer risk is associated with diets high in red meat. Heme, the pigment of red meat, induces cytotoxicity of colonic contents and elicits epithelial damage and compensatory hyperproliferation, leading to hyperplasia. Here we explore the possible causal role of the gut microbiota in heme-induced hyperproliferation. To this end, mice were fed a purified control or heme diet (0.5 μmol/g heme) with or without broad-spectrum antibiotics for 14 d. Heme-induced hyperproliferation was shown to depend on the presence of the gut microbiota, because hyperproliferation was completely eliminated by antibiotics, although heme-induced luminal cytotoxicity was sustained in these mice. Colon mucosa transcriptomics revealed that antibiotics block heme-induced differential expression of oncogenes, tumor suppressors, and cell turnover genes, implying that antibiotic treatment prevented the heme-dependent cytotoxic micelles to reach the epithelium. Our results indicate that this occurs because antibiotics reinforce the mucus barrier by eliminating sulfide-producing bacteria and mucin-degrading bacteria (e.g., Akkermansia). Sulfide potently reduces disulfide bonds and can drive mucin denaturation and microbial access to the mucus layer. This reduction results in formation of trisulfides that can be detected in vitro and in vivo. Therefore, trisulfides can serve as a novel marker of colonic mucolysis and thus as a proxy for mucus barrier reduction. In feces, antibiotics drastically decreased trisulfides but increased mucin polymers that can be lysed by sulfide. We conclude that the gut microbiota is required for heme-induced epithelial hyperproliferation and hyperplasia because of the capacity to reduce mucus barrier function

Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved

Red meat and processed meat intake is associated with a risk of colorectal cancer, a major cause of death in affluent countries. Epidemiological and experimental evidence supports the hypothesis that heme iron present in meat promotes colorectal cancer. This meta-analysis of prospective cohort studies of colon cancer reporting heme intake included 566,607 individuals and 4,734 cases of colon cancer. The summary relative risk of colon cancer was 1.18 [95%C.I.: 1.06-1.32] for subjects in the highest category of heme iron intake compared with those in the lowest category. Epidemiological data thus show a suggestive association between dietary heme and risk of colon cancer. The analysis of experimental studies in rats with chemically-induced colon cancer showed that dietary hemoglobin and red meat consistently promote aberrant crypt foci, a putative pre-cancer lesion. The mechanism is not known, but heme iron has a catalytic effect on (i) the endogenous formation of carcinogenic N-nitroso compounds and (ii) the formation of cytotoxic and genotoxic aldehydes by lipoperoxidation. A review of evidence supporting these hypotheses suggests that both pathways are involved in heme iron toxicit

Fostering Effective Data Management Practices at Leiden University

Modern and Contemporary Studie

Implementing a Research Data Policy at Leiden University

In this paper, we discuss the various stages of the institution-wide project that lead to the adoption of the data management policy at Leiden University in 2016. We illustrate this process by highlighting how we have involved all stakeholders. Each organisational unit was represented in the project teams. Results were discussed in a sounding board with both academic and support staff. Senior researchers acted as pioneers and raised awareness and commitment among their peers. By way of example, we present pilot projects from two faculties. We then describe the comprehensive implementation programme that will create facilities and services that must allow implementing the policy as well as monitoring and evaluating it. Finally, we will present lessons learnt and steps ahead. The engagement of all stakeholders, as well as explicit commitment from the Executive Board, has been an important key factor for the success of the project and will continue to be an important condition for the steps ahead

Freeze-Dried Ham Promotes Azoxymethane-Induced Mucin-Depleted Foci and Aberrant Crypt Foci in Rat Colon

Processed and red meat consumption is associated with the risk of colorectal cancer. Meta-analyses have suggested that the risk associated with processed meat is higher. Most processed meats are cured and cooked, which leads to formation of free nitrosyl heme. We speculated that free nitrosyl heme is more toxic than native myoglobin. The promoting effect of a freeze-dried, cooked, cured ham diet was looked for in a 100-day study. Colon carcinogenesis endpoints were aberrant crypt foci and mucin depleted foci (MDF). A second study (14 days) was designed 1) to compare the effect of ham, hemoglobin, and hemin; and 2) to test the effect of sodium chloride, nitrite, and phosphate in diet on early biomarkers associated with heme-induced promotion. In the 100-day study, control and ham-fed rats had 3.5 and 8.5 MDF/colon, respectively (P < 0.0001). Promotion was associated with cytotoxicity and lipid peroxidation. In the short-term study, cytotoxicity and lipid peroxidation of fecal water, and the urinary marker of lipid peroxidation, increased dramatically in ham- and hemin-fed rat. In contrast, the hemoglobin diet, sodium chloride, nitrite, phosphate diet had no effect. Freeze-dried cooked ham can promote colon carcinogenesis in a rodent model. Hemin, but not hemoglobin, mimicked ham effect on early biochemical markers associated with carcinogenesis