181 research outputs found
Generic e-learning platform for interactive educational simulations for use in university courses and individual studies online and offline
Dieckmann A. Generische E-Learning-Plattform für interaktive Lehrsimulationen zum Einsatz in Selbststudium und Präsenzlehre online und offline. Bielefeld (Germany): Bielefeld University; 2003.This doctoral thesis covers the design and implementation of an e-learning platform for interactive educational simulations. The simulations can be used in the context of university courses as well as for the purpose of individual studies. The data structures and storage mechanisms enable the use of any kind of multimedia contents, which can be classified and managed using arbitrary sets of metadata.
Educational units are treated as configurations of a simulation software. The data format for those configuration files can be based on XML (but does not have to). They are stored as the content of Virtual Directories, which also contain the individual media files needed for the simulations in the form of Virtual Learning Objects.
Each installation of the e-learning platform contains its own local database and is capable of interacting with other instances of the system via an XML-RPC communication mechanism. Hence the software can be used both online and offline. In online mode, new contents can be distributed or downloaded. It is also possible to integrate powerful communication functionalities like chats.
The integrated user management makes it possible to personalize the software and to specify access rights for reading, creating and modifying objects contained in the system. The e-learning framework was implemented in a platform-independent way using the JAVA programming language. The software can be extended by new components if necessary. For this purpose it was made available to the public under the terms of an open-source license. (For details please see the homepage of the Monist project, http://www.monist.de, where the software can be downloaded. The contact address for any questions is [email protected].)
The e-learning platform provides the necessary base technologies for a distributed e-learning system, especially powerful mechanisms for managing simulation data and metadata. But it is not meant to be a standalone e-learning system because the necessary simulation software and the specific contents of the particular field of study have to be integrated.
The Monist system serves as a reference implementation of the e-learning platform. It covers the field of computational neuroscience. The project team created a configurable simulation software, programmed an editor for such configurations and prepared a large amount of educational content. The combination of these three components makes a system that can fully benefit from the services offered by the e-learning platform.
For further use of the e-learning platform it is essential to create simulation software for other fields of study and to integrate it into the framework. The next step is the creation of a critical mass of specific content for the subject to make the system ready for educational use. To achieve a good level of user acceptance it is also necessary to hold courses using the e-learning system on a regular base and to create new contents from time to time. Both tasks require some efforts, but both are also supported by the e-learning platform.Mit der in der vorliegenden Arbeit entworfenen E-Learning-Plattform und ihrer parallel dazu erfolgten Implementierung in der Programmiersprache Java wurde eine technische Basis für die Verwendung interaktiver Lehrsimulationen geschaffen, die sowohl in der Präsenzlehre als auch im Selbststudium eingesetzt werden können. Die Datenstrukturen und Speichermechanismen ermöglichen das Einbringen von beliebigen, multimedialen Inhalten sowie deren Verwaltung durch den Gebrauch von frei definierbaren Metadaten. Einzelne Lehreinheiten können in Form von Konfigurationen der Simulationssoftware, beispielsweise in einem XML-basierten Datenformat, vorliegen und als Inhalt (content) von Virtuellen Verzeichnissen gespeichert werden, die außerdem die einzelnen Medien, die für die Zusammensetzung der betreffenden Simulation anhand der Konfigurationen erforderlich sind, in Form von Virtuellen Lernobjekten enthalten.
Durch die in jede Installation des Systems integrierte Datenbank und den verwendeten XML-RPC-Kommunikationsmechanismus ist die Benutzung der E-Learning-Plattform sowohl online als auch offline möglich. Im Online-Betrieb können dabei jederzeit neue Inhalte verbreitet bzw. heruntergeladen werden, und die Möglichkeit zur Integration von umfangreichen Kommunikationsfunktionalitäten ist ebenfalls gegeben. Die Verwaltung von Benutzern und Zugriffsrechten ermöglicht sowohl die Personalisierung des Systems als auch die Festlegung von Berechtigungen für das Lesen, Anlegen und Verändern von im System enthaltenen Objekten. Die Software ist plattformunabhängig implementiert und kann bei Bedarf beliebig erweitert werden. Zu diesem Zweck wird sie im Rahmen einer Open-Source-Politik zur Verfügung gestellt. (Siehe hierzu die Homepage des Projektes Monist, http://www.monist.de, auf der ein Download des Monist-Systems und der E-Learning-Plattform möglich ist. Als Kontaktadresse und für Fragen steht die E-Mail-Adresse [email protected] zur Verfügung.)
Die E-Learning-Plattform bietet die erforderlichen Basistechnologien für ein verteiltes E-Learning-System, ist jedoch für sich allein genommen noch kein derartiges System. Ohne die Integration der Lernsoftware sowie der fachlichen Inhalte würde sie nur eine leere Hülle darstellen, deren Funktionalität über die reine Datenverwaltung nicht hinaus ginge. Im Monist-System wurde eine konfigurierbare Simulationssoftware geschaffen, ein Editor für derartige Konfigurationen entwickelt und ein umfangreicher Grundstock an fachlichen Lerninhalten für das Gebiet der Neuro- und Kognitionswissenschaften angelegt. Durch das Zusammenwirken mit diesen drei Komponenten entsteht erst ein System, das den vollen Umfang der Funktionalitäten der E-Learning-Plattform nutzen kann und den beabsichtigten Einsatz in der universitären Lehre ermöglicht.
Für eine weitergehende Nutzung der E-Learning-Plattform ist es daher erforderlich, für andere Fachbereiche die Entwicklung entsprechender Simulationsprogramme vorzunehmen, diese und eventuell bereits vorhandene Software ins System zu integrieren sowie eine kritische Masse an fachspezifischen Inhalten bereitzustellen. Damit das System von den Lernenden dauerhaft angenommen wird, empfiehlt sich darüber hinaus das regelmäßige Abhalten von Lehrveranstaltungen unter Verwendung der elektronischen Lehre sowie die fortgesetzte Erstellung neuer Inhalte. Dies erfordert beides einen gewissen Aufwand, wird aber auch beides durch die E-Learning-Plattform unterstützt
Lrp4, a Novel Receptor for Dickkopf 1 and Sclerostin, Is Expressed by Osteoblasts and Regulates Bone Growth and Turnover In Vivo
Lrp4 is a multifunctional member of the low density lipoprotein-receptor gene family and a modulator of extracellular cell signaling pathways in development. For example, Lrp4 binds Wise, a secreted Wnt modulator and BMP antagonist. Lrp4 shares structural elements within the extracellular ligand binding domain with Lrp5 and Lrp6, two established Wnt co-receptors with important roles in osteogenesis. Sclerostin is a potent osteocyte secreted inhibitor of bone formation that directly binds Lrp5 and Lrp6 and modulates both BMP and Wnt signaling. The anti-osteogenic effect of sclerostin is thought to be mediated mainly by inhibition of Wnt signaling through Lrp5/6 within osteoblasts. Dickkopf1 (Dkk1) is another potent soluble Wnt inhibitor that binds to Lrp5 and Lrp6, can displace Lrp5-bound sclerostin and is itself regulated by BMPs. In a recent genome-wide association study of bone mineral density a significant modifier locus was detected near the SOST gene at 17q21, which encodes sclerostin. In addition, nonsynonymous SNPs in the LRP4 gene were suggestively associated with bone mineral density. Here we show that Lrp4 is expressed in bone and cultured osteoblasts and binds Dkk1 and sclerostin in vitro. MicroCT analysis of Lrp4 deficient mutant mice revealed shortened total femur length, reduced cortical femoral perimeter, and reduced total femur bone mineral content (BMC) and bone mineral density (BMD). Lumbar spine trabecular bone volume per total volume (BV/TV) was significantly reduced in the mutants and the serum and urinary bone turnover markers alkaline phosphatase, osteocalcin and desoxypyridinoline were increased. We conclude that Lrp4 is a novel osteoblast expressed Dkk1 and sclerostin receptor with a physiological role in the regulation of bone growth and turnover, which is likely mediated through its function as an integrator of Wnt and BMP signaling pathways
Entwicklung von Lehr- und Lernmaterialien zur Vermittlung prähistorischer Lebensbilder am Beispiel der Wildtiere zur Zeit des Neolithikums
Im Rahmen eines Kooperationsprojektes des Federseemuseums Bad Buchau mit den Pädagogischen Hochschulen Weingarten und Kreuzlingen (CH) ist diese Untersuchung als Teilprojekt des Lernangebotes „Der Steinzeit auf der Spur“ entwickelt worden. Ziel dieses Projektes ist, den Besuchern von außerschulischen Lernorten regionales Wissen nahe zu bringen und durch fächerübergreifende Lernangebote zu ergänzen. Das regionale Lernen wird durch die Entwicklung von Methoden und Materialien unterstützt. Es wird angestrebt, den Erfolg dieser Lernangebote durch weitere wissenschaftliche Arbeiten zu untersuchen und bewerten zu lassen, um eine Optimierung der Materialien zu gewährleisten. Innerhalb dieses Projektes möchte das Federseemuseum ein Programm für Schulklassen und Jugendgruppen anbieten, das sich mit den Forschungsmethoden der Archäologen beschäftigt. Durch die selbstständige Arbeit als Forscher sollen die Schüler einen Einblick in wissenschaftliches Arbeiten erhalten und dieses Wissen durch handlungsorientierte Aufgaben verinnerlichen. Das forschende Lernen steht also im Mittelpunkt eines weitreichenden Angebotes, welches sich hauptsächlich mit der Flora und Fauna des Neolithikums (Jungsteinzeit) beschäftigt. Die Themengebiete beinhalten Wild- und Nutzpflanzen, sowie Wild und Haustiere. Die Forschungsmethoden der Dendrochronologie und Typologie stellen weitere zu untersuchende Bereiche dar. Neben der Vermittlung von wissenschaftlichen Arbeitsweisen sollen die Schüler aber vor allem einen Einblick in prähistorische Lebensbilder erhalten. Durch die Beschäftigung mit diesem Thema sollen sich die Schüler einen intensiveren und individuellen Zugang zum Leben der Menschen der Jungsteinzeit erschließen. Ein Teilaspekt des Lernangebotes „Der Steinzeit auf der Spur“ wird in dieser Publikation vorgestellt. Am Beispiel der Wildtiere des Neolithikums wird eine Möglichkeit aufgezeigt, das forschende Lernen der Schüler anzuregen und durch die Wahl bestimmter Methoden umzusetzen
Microbially competent 3D skin: a test system that reveals insight into host–microbe interactions and their potential toxicological impact
The skin`s microbiome is predominantly commensalic, harbouring a metabolic potential far exceeding that of its host. While there is clear evidence that bacteria-dependent metabolism of pollutants modulates the toxicity for the host there is still a lack of models for investigating causality of microbiome-associated pathophysiology or toxicity. We now report on a biologically characterised microbial–skin tissue co-culture that allows studying microbe–host interactions for extended periods of time in situ. The system is based on a commercially available 3D skin model. In a proof-of-concept, this model was colonised with single and mixed cultures of two selected skin commensals. Two different methods were used to quantify the bacteria on the surface of the skin models. While Micrococcus luteus established a stable microbial–skin tissue co-culture, Pseudomonas oleovorans maintained slow continuous growth over the 8-day cultivation period. A detailed skin transcriptome analysis showed bacterial colonisation leading to up to 3318 significant changes. Additionally, FACS, ELISA and Western blot analyses were carried out to analyse secretion of cytokines and growth factors. Changes found in colonised skin varied depending on the bacterial species used and comprised immunomodulatory functions, such as secretion of IL-1α/β, Il-6, antimicrobial peptides and increased gene transcription of IL-10 and TLR2. The colonisation also influenced the secretion of growth factors such as VFGFA and FGF2. Notably, many of these changes have already previously been associated with the presence of skin commensals. Concomitantly, the model gained first insights on the microbiome’s influence on skin xenobiotic metabolism (i.e., CYP1A1, CYP1B1 and CYP2D6) and olfactory receptor expression. The system provides urgently needed experimental access for assessing the toxicological impact of microbiome-associated xenobiotic metabolism in situ
Predicting the spatial distribution of stoats, ship rats and weasels in a beech forest setting using GIS
Using trap data the Hawdon, Poulter and South Branch valleys, a spatial distribution model was created for Stoats (Mustela erminea), Ship Rats (Rattus rattus) and Weasels (Mustela nivalis) in the North Branch of the Hurunui River. Ten spatial attributes were analysed in this thesis as potential spatial predictors of Stoats, Ship rats or Weasels; four of which were distance related measurements (distance from ecotonal edge, distance from river, distance from river tributary and distance from trapping edge); three were climate based variables (mean maximum temperature, mean minimum temperature and mean precipitation) and three were topographical based variables (elevation, aspect and slope). Relationships that existed between each spatial attribute and the number of Stoats, Ship Rats and Weasels caught were quantified by comparing the significance of the mean trapping rate with each spatial attribute and expressed spatially as maps in a Geographical Information System (GIS). Results from this thesis found elevation, aspect and distance from ecotonal edge as potential spatial predictors of Stoat populations. Elevation and aspect were found to be potential predictors of Ship rat and Weasel populations. GIS is able to predict the spatial distribution of pest species to a similar (or better) level compared to more formal associative models. The potential of GIS is however, restrained by the same limitations associated with these models. By using a larger trapping data set and identifying a number of social interactions between Stoats, Ship Rats and Weasels, one can improve the accuracy of spatially modelling each species within a Beech forest environment. Therefore, improve our understanding how landscapes influence the distribution of each pest species
Study protocol of the German "Registry for the Detection of Late Sequelae after Radiotherapy in Childhood and Adolescence" (RiSK)
<p>Abstract</p> <p>Background</p> <p>Late effects after radiotherapy in childhood and adolescence have mainly been characterized retrospectively with small patient numbers. However, these analyses are limited due to little information regarding organ dose levels in many cases. To overcome this limitation, the German Group of Paediatric Radiation Oncology (APRO) established the „Registry for the evaluation of late side effects after radiation in childhood and adolescence” (RiSK). The study protocol and the documentation forms are given in this publication.</p> <p>Methods/Design</p> <p>Radiation parameters including detailed organ doses as well as toxicity evaluations are collected prospectively from centres all over Germany. Standardized documentation forms are used. These forms are given in an English and German version as additional files to this publication. Documentation is planned for all children who receive radiotherapy in one of the therapy trials of the "German Society of Paediatric Oncology and Haematology (GPOH)". The study started in a pilot phase in June 2001 in few centres. Since 2004 documentation has been performed all over Germany and is still on-going.</p> <p>Discussion</p> <p>To our knowledge, "RiSK" is the only multi-centre study that evaluates radiation associated side effects prospectively with detailed information about organ dose levels. With ongoing recruitment and prolongation of follow-up powerful data will be obtained in a few years. A broad use and international cooperation are welcome.</p
Correlation of Aqueous, Vitreous, and Serum Protein Levels in Patients With Retinal Diseases.
PURPOSE
To further establish aqueous humor (AH) as a clinically suitable source of protein biomarkers in retinal diseases by evaluating the correlation of a large panel of proteins between AH, vitreous humor (VH), and serum (SE).
METHODS
We enrolled 60 subjects (eyes) with various non-infectious retinal diseases. AH, VH, and SE proteins were analyzed using the Olink Target 96 platform (1196 protein assays in total). We compared these three matrices in terms of quantification overlap, principal component analysis, and correlation.
RESULTS
In the AH, VH, and SE samples, 841, 917, and 1133 proteins, respectively, were consistently quantified above the limit of detection in more than 30% of patients. AH and VH shared 812 of these proteins. AH and VH samples overlapped along principal component 1, but SE samples were distinct. We identified 490 proteins with significant (false discovery rate [FDR]-adjusted P 0.5) between AH and VH, compared to only 33 and 40 proteins for VH and SE and for AH and SE, respectively.
CONCLUSIONS
Due to a close correlation between protein concentrations in the AH and VH and a clear difference from the SE, AH has the potential to serve as a substitute for VH and may hold significance in identifying protein biomarkers and novel targets related to retinal diseases.
TRANSLATIONAL RELEVANCE
This study further supports AH as a clinically suitable source of protein biomarkers in retinal diseases. In addition, the identified AH and VH correlations can inform the selection of protein biomarker candidates in future translational research
Characterization of elastic scattering near a Feshbach resonance in rubidium 87
The s-wave scattering length for elastic collisions between 87Rb atoms in the
state |f,m_f>=|1,1> is measured in the vicinity of a Feshbach resonance near
1007 G. Experimentally, the scattering length is determined from the mean-field
driven expansion of a Bose-Einstein condensate in a homogeneous magnetic field.
The scattering length is measured as a function of the magnetic field and
agrees with the theoretical expectation. The position and the width of the
resonance are determined to be 1007.40 G and 0.20 G, respectively.Comment: 4 pages, 2 figures minor revisions: added Ref.6, included error bar
Betamethasone administration during pregnancy is associated with placental epigenetic changes with implications for inflammation
Background Glucocorticoids (GCs) play a pivotal role in fetal programming. Antenatal treatment with synthetic GCs (sGCs) in individuals in danger of preterm labor is common practice. Adverse short- and long-term effects of antenatal sGCs have been reported, but their effects on placental epigenetic characteristics have never been systematically studied in humans. Results We tested the association between exposure to the sGC betamethasone (BET) and placental DNA methylation (DNAm) in 52 exposed cases and 84 gestational-age-matched controls. We fine-mapped associated loci using targeted bisulfite sequencing. The association of placental DNAm with gene expression and co-expression analysis on implicated genes was performed in an independent cohort including 494 placentas. Exposure to BET was significantly associated with lower placenta DNAm at an enhancer of FKBP5. FKBP5 (FK506-binding protein 51) is a co-chaperone that modulates glucocorticoid receptor activity. Lower DNAm at this enhancer site was associated with higher expression of FKBP5 and a co-expressed gene module. This module is enriched for genes associated with preeclampsia and involved in inflammation and immune response. Conclusions Our findings suggest that BET exposure during pregnancy associates with few but lasting changes in placental DNAm and may promote a gene expression profile associated with placental dysfunction and increased inflammation. This may represent a pathway mediating GC-associated negative long-term consequences and health outcomes in offspring.Peer reviewe
The Metagenome-Derived Enzymes LipS and LipT Increase the Diversity of Known Lipases
Triacylglycerol lipases (EC 3.1.1.3) catalyze both hydrolysis and synthesis reactions with a broad spectrum of substrates rendering them especially suitable for many biotechnological applications. Most lipases used today originate from mesophilic organisms and are susceptible to thermal denaturation whereas only few possess high thermotolerance. Here, we report on the identification and characterization of two novel thermostable bacterial lipases identified by functional metagenomic screenings. Metagenomic libraries were constructed from enrichment cultures maintained at 65 to 75°C and screened resulting in the identification of initially 10 clones with lipolytic activities. Subsequently, two ORFs were identified encoding lipases, LipS and LipT. Comparative sequence analyses suggested that both enzymes are members of novel lipase families. LipS is a 30.2 kDa protein and revealed a half-life of 48 h at 70°C. The lipT gene encoded for a multimeric enzyme with a half-life of 3 h at 70°C. LipS had an optimum temperature at 70°C and LipT at 75°C. Both enzymes catalyzed hydrolysis of long-chain (C12 and C14) fatty acid esters and additionally hydrolyzed a number of industry-relevant substrates. LipS was highly specific for (R)-ibuprofen-phenyl ester with an enantiomeric excess (ee) of 99%. Furthermore, LipS was able to synthesize 1-propyl laurate and 1-tetradecyl myristate at 70°C with rates similar to those of the lipase CalB from Candida antarctica. LipS represents the first example of a thermostable metagenome-derived lipase with significant synthesis activities. Its X-ray structure was solved with a resolution of 1.99 Å revealing an unusually compact lid structure
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