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See detailA meta-analysis of the effectiveness of bilingual programs in Europe
Aleksic, Gabrijela UL; Ferring, Dieter UL; Martin, Romain UL

in International Congress on Education, Innovation and Learning Technologies (2014, July)

The effectiveness of bilingual programs for promoting academic achievement of language-minority in the United States has been examined in six meta-analyses. The present meta-analytic study investigates ... [more ▼]

The effectiveness of bilingual programs for promoting academic achievement of language-minority in the United States has been examined in six meta-analyses. The present meta-analytic study investigates this topic for the first time in the European context. Thorough literature searches uncovered 101 European studies, with only seven meeting the inclusion criteria. Two studies were excluded from further analyses. Results from the random-effects model of the five remaining studies indicate a small positive effect (g = 0.23; 95% CI [0.10, 0.36]) for bilingual over submersion programs on reading of language-minority children. Thus, this meta-analysis supports bilingual education—that is, including the home language of language-minority children—in school instruction. However, the generalizability of the results is limited by the small number of studies on this topic. More published studies on bilingual education in Europe are needed as well as closer attention to the size of the effects. [less ▲]

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See detailA meta-analysis of the effectiveness of bilingual programs in Europe
Aleksic, Gabrijela UL; Ferring, Dieter UL; Martin, Romain UL

Scientific Conference (2014, June)

The effectiveness of bilingual programs for promoting academic achievement of language-minority in the United States has been examined in six meta-analyses. The present meta-analytic study investigates ... [more ▼]

The effectiveness of bilingual programs for promoting academic achievement of language-minority in the United States has been examined in six meta-analyses. The present meta-analytic study investigates this topic for the first time in the European context. Thorough literature searches uncovered 101 European studies, with only seven meeting the inclusion criteria. Two studies were excluded from further analyses. Results from the random-effects model of the five remaining studies indicate a small positive effect (g = 0.23; 95% CI [0.10, 0.36]) for bilingual over submersion programs on reading of language-minority children. Thus, this meta-analysis supports bilingual education—that is, including the home language of language-minority children—in school instruction. However, the generalizability of the results is limited by the small number of studies on this topic. More published studies on bilingual education in Europe are needed as well as closer attention to the size of the effects. [less ▲]

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See detailFinal report of the effectiveness study in Virtual Coach Reaches Out to me project
Aleksic, Gabrijela UL; Roelofsma, Peter

Report (2014)

One out of three persons in our society suffers from social or emotional loneliness. This percentage is even higher in the population of people who suffer from chronic diseases. Loneliness has pervasive ... [more ▼]

One out of three persons in our society suffers from social or emotional loneliness. This percentage is even higher in the population of people who suffer from chronic diseases. Loneliness has pervasive effects on mental health but it also has negative effects on physical well-being. The aim of this paper is to present a series of pilot studies evaluating the development of an ambient virtual coaching system. This system, called V2me (Virtual Coach reaches Out to Me) offers a friendship enrichment course for people in need for improving their social network. Several pilot studies were performed with about 50 participants in total who evaluated the system that was developed using a living lab approach. In this approach new health media was developed from a user-centered process that allows frequent iterations of user evaluation and involvement. The paper presents the results of the first five iterations. The reactions on receiving the system and experiences during instruction were increasingly positive over these iterations of the system development phase. Over time the system has passed the user’s choice selection criteria. Participants have been expressing a clear interest for choosing and wanting to use the system in their daily lives. However, the system did not pass the persistent use selection criteria when the system was brought and left for independent use. It appeared that participants did not use it very much during the day as expected. Moreover, participants did not perform all the tasks (i.e., messaging, Skyping) that they were asked to achieve on a daily basis. The final goal of the V2me system, i.e. establishing social relations between elderly persons, was not achieved as well, although this might be due to the limited time space of using the system and its facilities. Given these observation, it is concluded that more iterations in the system development are needed for the system in order to pass the habitual use criteria which is needed for its effectiveness. [less ▲]

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See detailPersonality traits and the marriage market
Dupuy, Arnaud UL; Galichon, Alfred

in Journal of Political Economy (2014)

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See detailEntropy Methods for Identifying Hedonic Models
Dupuy, Arnaud UL; Galichon, Alfred; Henry, Marc

in Mathematics and Financial Economics (2014)

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See detailOn Input Market Frictions and Estimation of Factors Demand
Dupuy, Arnaud UL; Sorensen, Todd

in Southern Economic Journal (2014)

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See detailState-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology.
Alepee, Natalie; Bahinski, Anthony; Daneshian, Mardas et al

in ALTEX (2014), 31(4), 441-77

Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk ... [more ▼]

Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing. [less ▲]

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See detailLong-term maintenance of HepaRG cells in serum-free conditions and application in a repeated dose study.
Klein, Sebastian; Mueller, Daniel; Schevchenko, Valery et al

in Journal of applied toxicology : JAT (2014), 34(10), 1078-86

Chronic repeated-dose toxicity studies are still carried out on animals and often do not correlate with the effects in human beings mainly due to species-specific differences in biotransformation. The ... [more ▼]

Chronic repeated-dose toxicity studies are still carried out on animals and often do not correlate with the effects in human beings mainly due to species-specific differences in biotransformation. The human hepatoma cell line HepaRG has been used for human relevant toxicity assessment. However, HepaRG cells are commonly maintained in serum containing medium which limits their use in 'omics'-based toxicology. In this study, we compared the maintenance of HepaRG cells in standard serum-supplemented and serum-free conditions. Viability and Cytochrome P450 (CYP) activity during long-term cultivation were assessed. Liver-specific albumin and urea production was measured. The extracellular metabolome (amino acids, glucose, lactate and pyruvate) was measured to compare different cultivation conditions using metabolic flux analysis. Although metabolic flux analysis reveals differences in certain parts of the metabolism, e.g. production of urea, the overall metabolism of serum-free and serum-supplemented cultured HepaRG cells is similar. We conclude that HepaRG cells can be maintained in optimized serum-free conditions for 30 days without viability change and with high CYP activity. We also tested the acute (24 h) and long-term repeated-dose (7 doses, every second day) toxicity of valproic acid. We calculated an EC50 value of 1.4 mM after repeated exposure which is close to the cmax value for valproic acid. Maintenance of HepaRG cells in serum-free conditions opens up the opportunity for the use of these cells in human long-term repeated-dose hepatotoxicity studies and for application in systems toxicology. [less ▲]

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See detail3D organotypic HepaRG cultures as in vitro model for acute and repeated dose toxicity studies.
Mueller, Daniel; Kramer, Lisa; Hoffmann, Esther et al

in Toxicology in vitro : an international journal published in association with BIBRA (2014), 28(1), 104-12

Predictive in vitro models alternative to in vivo animal will have a significant impact in toxicology. Conventional 2D models do not reflect the complexity of a 3D organ resulting in discrepancies between ... [more ▼]

Predictive in vitro models alternative to in vivo animal will have a significant impact in toxicology. Conventional 2D models do not reflect the complexity of a 3D organ resulting in discrepancies between experimental in vitro and in vivo data. Using 3D HepaRG organotypic cultures we tested four drugs (aflatoxin B1, amiodarone, valproic acid and chlorpromazine) for toxic effects and compared the results with 2D HepaRG and HepG2 cultures. We show that 3D HepaRG cultures are more sensitive than the other tested cultures to aflatoxin B1 which is only toxic upon metabolic activation in the liver. We observed that CYP3A4 activity is higher in the 3D HepaRG cultures compared to the 2D HepaRG cultures. Furthermore, we investigated repeated dose toxicity of chlorpromazine and assessed its effects on glucose and lactate metabolism. Sub-toxic concentrations of chlorpromazine induced significant metabolic changes in both 2D and 3D HepaRG cultures upon acute and repeated dose (3 doses) exposure. In summary, our data support the hypothesis that 3D cell culture models better mimic the in vivo tissue and improve cellular functionality. The 3D HepaRG organotypic cultures represent a high throughput system for drug toxicity screening. This system is therefore a promising tool in preclinical testing of human relevance which can allow reducing and/or replacing animal testing for drug adverse effects. [less ▲]

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See detailIdentification of predictors of emergent literacy
Aleksic, Gabrijela UL; Merrell, Christine; Ferring, Dieter UL et al

in The 16th European Conference on Developmental Psychology (2013, September)

Two studies examined the predictive value of a range of variables associated with young children on their later literacy. Study 1 involved children age 5 to 7 from Serbia (N = 159); Study 2 engaged ... [more ▼]

Two studies examined the predictive value of a range of variables associated with young children on their later literacy. Study 1 involved children age 5 to 7 from Serbia (N = 159); Study 2 engaged children age 4 to 6 from Luxembourg (N = 174). Children in Study 1 were assessed on entry to school, aged 5, and again at age 7. Children in Study 2 were assessed once, in preschool. In Study 1, multilevel models indicated that a baseline assessment administrated in school language at the age of 5, in particular with respect to their competence in mathematics, were the most significant predictors of children’s emergent literacy at the age of 7 after controlling for age, gender, vocabulary, and phonological awareness. In Study 2, gender, vocabulary, phonological awareness, and competence in mathematics at the age of 5 were significant predictors of emergent literacy at the same age, after controlling for age, test administered in school language, and behavior. The level of parental education in Study 1 and the children’s behavior in both studies proved not to be significant. Both studies have important educational implications, suggesting that practitioners should assess language-minority children at the start of school in their mother tongue and act upon the outcomes of those assessments to avoid later literacy problems. [less ▲]

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See detailEvaluation of V2me: A Virtual Coaching System for Loneliness Prevention and Intervention
Roelofsma, Peter; Ferring, Dieter UL; Aleksic, Gabrijela UL

in Medicine 2.0: Social Media, Mobile Apps and Internet/Web 2.0 (2013, September)

One out of three persons in our society suffers from social or emotional loneliness. This percentage is even higher in the population of people who suffer from chronic diseases. Loneliness has pervasive ... [more ▼]

One out of three persons in our society suffers from social or emotional loneliness. This percentage is even higher in the population of people who suffer from chronic diseases. Loneliness has pervasive effects on mental health but it also has negative effects on physical well-being. The aim of this paper is to present a series of pilot studies evaluating the development of an ambient virtual coaching system. This system, called V2me (Virtual Coach reaches Out to Me) offers a friendship enrichment course for people in need for improving their social network. Several pilot studies were performed with about 50 participants in total who evaluated the system that was developed using a living lab approach. In this approach new health media was developed from a user-centered process that allows frequent iterations of user evaluation and involvement. The paper presents the results of the first five iterations. The reactions on receiving the system and experiences during instruction were increasingly positive over these iterations of the system development phase. Over time the system has passed the user’s choice selection criteria. Participants have been expressing a clear interest for choosing and wanting to use the system in their daily lives. However, the system did not pass the persistent use selection criteria when the system was brought and left for independent use. It appeared that participants did not use it very much during the day as expected. Moreover, participants did not perform all the tasks (i.e., messaging, Skyping) that they were asked to achieve on a daily basis. The final goal of the V2me system, i.e. establishing social relations between elderly persons, was not achieved as well, although this might be due to the limited time space of using the system and its facilities. Given these observation, it is concluded that more iterations in the system development are needed for the system in order to pass the habitual use criteria which is needed for its effectiveness. [less ▲]

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See detailImportance de la langue maternelle pour le development des enfants au Luxembourg
Aleksic, Gabrijela UL

Article for general public (2013)

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See detailA meta-analysis of the effectiveness of bilingual programs in Europe
Aleksic, Gabrijela UL; Ferring, Dieter UL; Martin, Romain UL

in The 9th International Symposium on Bilingualism (2013, June)

The effectiveness of bilingual programs for promoting academic achievement of language-minority in the United States has been examined in six meta-analyses. The present meta-analytic study investigates ... [more ▼]

The effectiveness of bilingual programs for promoting academic achievement of language-minority in the United States has been examined in six meta-analyses. The present meta-analytic study investigates this topic for the first time in the European context. Thorough literature searches uncovered 101 European studies, with only seven meeting the inclusion criteria. Two studies were excluded from further analyses. Results from the random-effects model of the five remaining studies indicate a small positive effect (g = 0.23; 95% CI [0.10, 0.36]) for bilingual over submersion programs on reading of language-minority children. Thus, this meta-analysis supports bilingual education—that is, including the home language of language-minority children—in school instruction. However, the generalizability of the results is limited by the small number of studies on this topic. More published studies on bilingual education in Europe are needed as well as closer attention to the size of the effects. [less ▲]

Detailed reference viewed: 8 (1 UL)
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See detailA l'école les programmes bilingues sont très efficaces
Aleksic, Gabrijela UL

Article for general public (2013)

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See detailVirtual Coach Reaches Out To Me
Aleksic, Gabrijela UL

Conference given outside the academic context (2013)

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See detailVirtual Coach Reaches Out To Me
Aleksic, Gabrijela UL

Conference given outside the academic context (2013)

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See detailMetabolomics in toxicology and preclinical research.
Ramirez, Tzutzuy; Daneshian, Mardas; Kamp, Hennicke et al

in ALTEX (2013), 30(2), 209-25

Metabolomics, the comprehensive analysis of metabolites in a biological system, provides detailed information about the biochemical/physiological status of a biological system, and about the changes ... [more ▼]

Metabolomics, the comprehensive analysis of metabolites in a biological system, provides detailed information about the biochemical/physiological status of a biological system, and about the changes caused by chemicals. Metabolomics analysis is used in many fields, ranging from the analysis of the physiological status of genetically modified organisms in safety science to the evaluation of human health conditions. In toxicology, metabolomics is the -omics discipline that is most closely related to classical knowledge of disturbed biochemical pathways. It allows rapid identification of the potential targets of a hazardous compound. It can give information on target organs and often can help to improve our understanding regarding the mode-of-action of a given compound. Such insights aid the discovery of biomarkers that either indicate pathophysiological conditions or help the monitoring of the efficacy of drug therapies. The first toxicological applications of metabolomics were for mechanistic research, but different ways to use the technology in a regulatory context are being explored. Ideally, further progress in that direction will position the metabolomics approach to address the challenges of toxicology of the 21st century. To address these issues, scientists from academia, industry, and regulatory bodies came together in a workshop to discuss the current status of applied metabolomics and its potential in the safety assessment of compounds. We report here on the conclusions of three working groups addressing questions regarding 1) metabolomics for in vitro studies 2) the appropriate use of metabolomics in systems toxicology, and 3) use of metabolomics in a regulatory context. [less ▲]

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See detail3D organotypic cultures of human HepaRG cells: a tool for in vitro toxicity studies.
Gunness, Patrina; Mueller, Daniel; Shevchenko, Valery et al

in Toxicological sciences : an official journal of the Society of Toxicology (2013), 133(1), 67-78

Drug-induced human hepatotoxicity is difficult to predict using the current in vitro systems. In this study, long-term 3D organotypic cultures of the human hepatoma HepaRG cell line were prepared using a ... [more ▼]

Drug-induced human hepatotoxicity is difficult to predict using the current in vitro systems. In this study, long-term 3D organotypic cultures of the human hepatoma HepaRG cell line were prepared using a high-throughput hanging drop method. The organotypic cultures were maintained for 3 weeks and assessed for (1) liver specific functions, including phase I enzyme and transporter activities, (2) expression of liver-specific proteins, and (3) responses to three drugs (acetaminophen, troglitazone, and rosiglitazone). Our results show that the organotypic cultures maintain high liver-specific functionality during 3 weeks of culture. The immunohistochemistry analyses illustrate that the organotypic cultures express liver-specific markers such as albumin, CYP3A4, CYP2E1, and MRP-2 throughout the cultivation period. Accordingly, the production rates of albumin and glucose, as well as CYP2E1 activity, were significantly higher in the 3D versus the 2D cultures. Toxicity studies show that the organotypic cultures are more sensitive to acetaminophen- and rosiglitazone-induced toxicity but less sensitive to troglitazone-induced toxicity than the 2D cultures. Furthermore, the EC50 value (2.7mM) for acetaminophen on the 3D cultures was similar to in vivo toxicity. In summary, the results from our study suggest that the 3D organotypic HepaRG culture is a promising in vitro tool for more accurate assessment of acute and also possibly for chronic drug-induced hepatotoxicity. [less ▲]

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See detailReal-time in situ viability assessment in a 3D bioreactor with liver cells using resazurin assay.
Mueller, Daniel; Tascher, Georg; Damm, Georg et al

in Cytotechnology (2013), 65(2), 297-305

Three-dimensional cultivation of human cells is promising especially for long-term maintenance of specific functions and mimicking the in vivo tissue environment. However, direct viability assessment is ... [more ▼]

Three-dimensional cultivation of human cells is promising especially for long-term maintenance of specific functions and mimicking the in vivo tissue environment. However, direct viability assessment is very difficult in such systems. Commonly applied indirect methods such as glucose consumption, albumin or urea production are greatly affected by culture conditions, stress and time of cultivation and do not reflect the real time viability of the cells. In this study we established a real-time in situ viability assay namely; resazurin assay, in a 3D hollow-fiber bioreactor using human liver cells. Resazurin assay is based on the conversion of resazurin to a fluorescent dye by cytoplasmatic and mitochondrial enzymes. We show that the resazurin reagent in concentrations used in this study is non-toxic and could be rapidly removed out of the system. Moreover, we observed that dead cells do not affect the results of the assay. We optimized the assay on HepG2 cells and tested it with primary human hepatocytes. Moreover, we maintained primary human hepatocytes in the 3D bioreactor system in serum-free conditions and also assessed viability before and after the exposure to amiodarone using the resazurin assay. We show that this approach is applicable during long-term cultivation of cells in bioreactors under different conditions and can moreover be applied to pharmacological studies, e.g. investigation of chronic drug effects in such 3D bioreactors. [less ▲]

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