Promoting learning through social cues in learning materials: Design approaches, theoretical explanations, empirical basis, and neglected aspects

Soziale Hinweisreize sind wesentliche Komponenten aller Arten von Lernmaterialien. Sie umfassen verbale, nonverbale sowie paraverbale Reize als auch wechselseitig aufeinander bezogene Reizfolgen. Obwohl soziale Hinweisreize in Lernmaterialien schon seit längerem untersucht werden, ist ihre systematische Erforschung noch jung. Sie umfasst primär kognitive, motivationale, affektive und soziale Prozesse, welche durch die Verwendung sozialer Hinweisreize in Lernmaterial ausgelöst oder beeinflusst werden. Ein Schwerpunkt der empirischen Forschung liegt dabei schon länger auf sozialen Prozessen. Von sozialen Reizen wird dabei angenommen, dass sie den Lernprozess positiv beeinflussen, u.a. indem sie bei den Lernenden den Eindruck sozialer Präsenz einer (Lehr-)Person stimulieren, was in der Folge zu mehr Lernmotivation, mehr Lernen auf Verständnis und letztendlich besseren Leistungen in Lerntests führt. In diesem Beitrag bieten wir eine Klassifikation der Vielfalt an sozialen Hinweisreizen in Lernmaterialien allgemein an, skizzieren ihre Wirkung über soziale Prozesse auf das Lernen, fassen einschlägige empirische Belege zusammen und diskutieren vernachlässigte Aspekte sozialer Hinweisreize.Social cues are an essential component of all types of learning material. They comprise verbal, non-verbal and para-verbal stimuli as well as mutually related sequences of stimuli. Although the investigation of social cues in learning materials has had a long history, systematic research on this topic is limited. The research has primarily included cognitive, motivational, affective and social processes that are triggered or influenced by the use of social cues in learning material. One prominent focus of the empirical research on social cues has been on social processes. Social cues are assumed to have a positive influence on the learning process, for example, by stimulating the impression of a person’s (teacher) social presence, which leads to increased motivation to learn, more learning to understand, and finally to better performance in learning tests. In this paper, we outline the variety of social cues in learning materials, outline their impact on learning via social processes, summarize the relevant empirical evidence, and discuss neglected aspects of social cues

Large meta-analysis of genome-wide association studies identifies five loci for lean body mass

Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p < 5 x 10(-8)) or suggestively genome wide (p < 2.3 x 10(-6)). Replication in 63,475 (47,227 of European ancestry) individuals from 33 cohorts for whole body lean body mass and in 45,090 (42,360 of European ancestry) subjects from 25 cohorts for appendicular lean body mass was successful for five single-nucleotide polymorphisms in/ near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO for total lean body mass and for three single-nucleotide polymorphisms in/ near VCAN, ADAMTSL3, and IRS1 for appendicular lean body mass. Our findings provide new insight into the genetics of lean body mass

Heme oxygenase 1 protects human colonocytes against ROS formation, oxidative DNA damage and cytotoxicity induced by heme iron, but not inorganic iron

The consumption of red meat is probably carcinogenic to humans and is associated with an increased risk to develop colorectal cancer (CRC). Red meat contains high amounts of heme iron, which is thought to play a causal role in tumor formation. In this study, we investigated the genotoxic and cytotoxic effects of heme iron (i.e., hemin) versus inorganic iron in human colonic epithelial cells (HCEC), human CRC cell lines and murine intestinal organoids. Hemin catalyzed the formation of reactive oxygen species (ROS) and induced oxidative DNA damage as well as DNA strand breaks in both HCEC and CRC cells. In contrast, inorganic iron hardly affected ROS levels and only slightly increased DNA damage. Hemin, but not inorganic iron, caused cell death and reduced cell viability. This occurred preferentially in non-malignant HCEC, which was corroborated in intestinal organoids. Both hemin and inorganic iron were taken up into HCEC and CRC cells, however with differential kinetics and efficiency. Hemin caused stabilization and nuclear translocation of Nrf2, which induced heme oxygenase-1 (HO-1) and ferritin heavy chain (FtH). This was not observed after inorganic iron treatment. Chemical inhibition or genetic knockdown of HO-1 potentiated hemin-triggered ROS generation and oxidative DNA damage preferentially in HCEC. Furthermore, HO-1 abrogation strongly augmented the cytotoxic effects of hemin in HCEC, revealing its pivotal function in colonocytes and highlighting the toxicity of free intracellular heme iron. Taken together, this study demonstrated that hemin, but not inorganic iron, induces ROS and DNA damage, resulting in a preferential cytotoxicity in non-malignant intestinal epithelial cells. Importantly, HO-1 conferred protection against the detrimental effects of hemin

Pharmacokinetics and sedative effects of intramuscular medetomidine in domestic sheep

Intramuscular (i.m.) administration of medetomidine (MED) may avoid the severe pressor effects caused by peripheral actions of MED associated with intravenous (i.v.) dosing. The purpose of this study was to determine the pharmacokinetics, the time course of sedation and occurence of hypoxaemia after i.m. administration of MED in domestic sheep. The MED was injected i.m. at a dose of 30 micro g/kg in nine domestic sheep. Blood was sampled at 0, 5, 10, 20, 30, 40, 60, 120, 180, 240, 360 and 600 min after MED. Sedation was assessed and arterial blood samples were taken before and 35 min after MED application. Mean (SD) pharmacokinetic parameters of i.m. MED were: absorption half-life: 13.2 (7.5) min; terminal half-life: 32.7 (14.9) min; time to peak concentration: 29.2 (8.9) min; peak concentration: 4.98 (1.89) ng/mL; volume of distribution: 3.9 (2.4) l/kg; total body clearance: 81.0 (21.5) mL/(min kg). Peak sedation occurred between 30 and 40 min after injection of MED. The degree of sedation correlated with individual plasma concentrations (rS: 0.926). One animal became hypoxaemic (PaO2 = 54.1 mmHg)

Heme oxygenase 1 protects human colonocytes against ROS formation, oxidative DNA damage and cytotoxicity induced by heme iron, but not inorganic iron

The consumption of red meat is probably carcinogenic to humans and is associated with an increased risk to develop colorectal cancer (CRC). Red meat contains high amounts of heme iron, which is thought to play a causal role in tumor formation. In this study, we investigated the genotoxic and cytotoxic effects of heme iron (i.e., hemin) versus inorganic iron in human colonic epithelial cells (HCEC), human CRC cell lines and murine intestinal organoids. Hemin catalyzed the formation of reactive oxygen species (ROS) and induced oxidative DNA damage as well as DNA strand breaks in both HCEC and CRC cells. In contrast, inorganic iron hardly affected ROS levels and only slightly increased DNA damage. Hemin, but not inorganic iron, caused cell death and reduced cell viability. This occurred preferentially in non-malignant HCEC, which was corroborated in intestinal organoids. Both hemin and inorganic iron were taken up into HCEC and CRC cells, however with differential kinetics and efficiency. Hemin caused stabilization and nuclear translocation of Nrf2, which induced heme oxygenase-1 (HO-1) and ferritin heavy chain (FtH). This was not observed after inorganic iron treatment. Chemical inhibition or genetic knockdown of HO-1 potentiated hemin-triggered ROS generation and oxidative DNA damage preferentially in HCEC. Furthermore, HO-1 abrogation strongly augmented the cytotoxic effects of hemin in HCEC, revealing its pivotal function in colonocytes and highlighting the toxicity of free intracellular heme iron. Taken together, this study demonstrated that hemin, but not inorganic iron, induces ROS and DNA damage, resulting in a preferential cytotoxicity in non-malignant intestinal epithelial cells. Importantly, HO-1 conferred protection against the detrimental effects of hemin

اهداف و دستاوردها

This is the second volume of the Young Cities Research Papers series presenting the scientific results from the mutual Iranian-German research project “Young Cities—Urban Energy Efficiency. Developing Energy- Efficient Urban Fabric in the Tehran-Karaj Region”. The project is funded for the German side by the German Federal Ministry of Education and Research BMBF. From the Iranian side, the Building and Housing Research Center BHRC and the New Towns Development Corporation NTDC as the main project partners are both affiliated to the Ministry of Housing and Urban Development MHUD. The Young Cities Research Papers shall disseminate the scientific results gained from the Young Cities project and the related PhD, post doctoral and senior expert research. The first two volumes are published following the completion of the first of the overall project’s pilot project, i.e. the New Quality pilot project buildings in Hashtgerd New Town. Hashtgerd New Town, 65 km to the west of Tehran and 30 km to the west of Karaj in the Alborz Province in Iran, forms the spatial focus of the Young Cities project. It is the place of intervention and for testing and trying the solutions and concepts developed for energy-efficient and sustainable urban design and planning, infrastructure provision, and object planning by the Iranian and German project partners. The solutions and concepts shall, however, be applicable and transferable to other places in the Tehran-Karaj region as well as in Iran and in the Middle East North Africa region MENA. The New Quality buildings as the first of the pilot projects to be completed are residential buildings. It was planned jointly by the Iranian and German partners from a typical Iranian residential building scheme widely to be found in the region’s new settlements and New Towns and adapted by small scale interventions for economical improvements regarding building quality, construction layout, and energy-efficiency. The pilot project has been erected by the Housing Investment Company hic, Tehran, under supervision of BHRC and TU Berlin including an on-site vocational training workshop for construction site staff aiming at improved building quality and use of the new materials and construction technologies introduced. The erection of the New Quality pilot project, now, is completed. The pilot project, however, goes on by the seamless start of monitoring of the buildings performance during use regarding energy consumption, water consumption and building quality. The results from the monitoring will be fed into the development of the other pilot projects, into the tested and tried concepts and solutions to be presented and disseminated as the project’s output, and into the project evaluation assessing the effects from the project. The present second volume is to introduce the overall Young Cities project with its accomplishments up to August 2010. It is divided into four main parts on the background of the project, its objectives and methodological approach, the results and accomplishments reached so far, and an outlook on the future progress of the project. The accomplishments form the main part and the focus of the volume since the series is devoted primarily to the results from the project. However, as the first volume in English language, the Young Cities project is also introduced with respect to some background information and primarily to its objectives and methodology forming the introduction into the whole series as is the first volume for Farsi language readers. Printed Version published by Universitätsverlag der TU Berlin (www.univerlag.tu-berlin.de), ISBN 978-3-7983-2387-