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See detailSystematic Trading Behavior and the Cross-Section of Stock Returns on the OMXH
Leung, Henry; Rose, Annica UL; Westerholm, P. Joakim

in Review of Finance (2014), 18(6), 2325-2374

Signed small trade turnover (SSTT) measures temporary uninformed buy or sell pressure that is initiated by small trades in the same direction. Using Nasdaq OMX Helsinki tick-by-tick trade data with known ... [more ▼]

Signed small trade turnover (SSTT) measures temporary uninformed buy or sell pressure that is initiated by small trades in the same direction. Using Nasdaq OMX Helsinki tick-by-tick trade data with known investor category, we confirm that SSTT is a robust proxy for uninformed trading. In the short term (1–3 months), stocks with a high proportion of signed small trades outperform, but in the medium (4–6 months) and long term (7–36 months), SSTT by individual investors has a negative correlation to stock returns, while SSTT by institutional investors and foreign nominees is not related to stock returns. Systematic trading behavior appears to better explain the excess return generated by the low SSTT portfolio relative to the high SSTT portfolio when compared to traditional risk factors in the CAPM and Fama-French models. In the aggregate, small trades are noise in the spirit of Kyle (1985) and Black (1986), but small trade behavior impacts the performance of individuals and not the performance of institutions. Large trades by both individuals and institutions perform better in the intermediate and long term, which lends some credibility to the practice of classifying larger trades as informed, but our results show that these trades are not always by institutions. [less ▲]

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See detailSystematic trading behaviour and its informational effect: evidence from the OMXH
Rose, Annica UL

in Applied Financial Economics (2014), 24(22), 1421-1427

By using signed small trade turnover (SSTT) as a proxy of investors’ systematic trading behaviour and permanent price effect (PPE) as a proxy for informed trading, this article investigates the short-term ... [more ▼]

By using signed small trade turnover (SSTT) as a proxy of investors’ systematic trading behaviour and permanent price effect (PPE) as a proxy for informed trading, this article investigates the short-term outperformance of high SSTT stocks for categories of investors on the NASDAQ OMX Helsinki (OMXH) and whether the outperformance is best understood in the context of investor trading behaviour or informed trading. This study finds that the trading of high SSTT stocks is associated with a lower PPE than the trading of low SSTT stocks, which implies that the trading of high SSTT stocks is less informed than the trading of low SSTT stocks, and that the short-term outperformance of high SSTT stocks relative to low SSTT stocks is best explained within the behavioural finance framework, that is, by investors’ bias towards popular stocks proxied by SSTT, and not within the rational framework, that is, by informed trading proxied by the PPE. These findings are economically and statistically significant for all types of investors. [less ▲]

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See detailThe systematic variation of task characteristics facilitates the understanding of task difficulty: A cognitive diagnostic modeling approach to complex problem solving
Greiff, Samuel UL; Krkovic, Katarina UL; Nagy, Gabriel

in Psychological Test and Assessment Modeling (2014), 56(1), 83-103

Since the 1960ies, when pioneering research on Item Response Theory (IRT) was published, considerable progress has been made with regard to the psychometrical quality of psychological assessment tools ... [more ▼]

Since the 1960ies, when pioneering research on Item Response Theory (IRT) was published, considerable progress has been made with regard to the psychometrical quality of psychological assessment tools. One recent development building upon IRT is the introduction of Cognitive Diagnostic Modeling (CDM). The major goal of introducing CDM was to develop methods that allow for examining which cognitive processes are involved when a person is working on a specific assessment task. More precisely, CDM enables researchers to investigate whether assumed task characteristics drive item difficulty and, thus, person ability parameters. This may – at least according to the assumption inherent in CDM - allow conclusions about cognitive processes involved in assessment tasks. In this study, out of the numerous CDMs available the Least Square Distance Method (LSDM; Dimitrov, 2012) was applied to investigate psychometrical qualities of an assessment instrument measuring Complex Problem Solving (CPS) skills. For the purpose of the study, two task characteristics essential for mastering CPS tasks were identified ex-ante – degree of connectivity and presence of indirect effects by adding eigendynamics to the task. The study examined whether and how the two hypothesized task characteristics drive item difficulty of two CPS dimensions, knowledge acquisition and knowledge application. The sample consisted of 490 German high school students, who completed the computer-based CPS assessment instrument MicroDYN. The two task characteristics in MicroDYN items were varied systematically. Results obtained in LSDM indicated that the two hypothesized task characteristics, degree of connectivity and introducing indirect effects, drove item difficulty only for knowledge acquisition. Hence, other task characteristics that may determine item difficulty of knowledge application need to be investigated in future studies in order to provide a sound measurement of CPS. [less ▲]

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See detailSystematische Erforschung komplexer Problemlösefähigkeit anhand minimal komplexer Systeme
Greiff, Samuel UL; Funke, Joachim

in Zeitschrift für Pädagogik. Beiheft (2010), 56

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See detailLe système juridique français à l'ère de la contractualisation
Hiez, David UL; Chassagnard-Pinet, Sandrine

in La contractualisation de la production normative (2008)

Detailed reference viewed: 61 (0 UL)
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See detailUn système plurilingue peut-il être efficace?
Martin, Romain UL; Houssemand, Claude UL

in Cahiers du Service de Pédagogie Expérimentale (SPE) (2003, September), 15(16), 157-164

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See detailLe système scolaire luxembourgeois : aperçu et tendances
Lenz, Thomas UL; Heinz, Andreas UL

in LUCET; SCRIPT (Eds.) Rapport national sur l'éducation au Luxembourg 2018 (2018)

Cet article donne un aperçu des principaux faits et chiffres du système scolaire luxembourgeois et présente les développements réalisés au cours des dernières années. L’accent est mis en particulier sur ... [more ▼]

Cet article donne un aperçu des principaux faits et chiffres du système scolaire luxembourgeois et présente les développements réalisés au cours des dernières années. L’accent est mis en particulier sur la transition de l’enseignement fondamental à l’enseignement secondaire. À cet égard, d’importantes différences sont en partie observées en fonction du sexe, des nationalités et entre différentes communes du Luxembourg. [less ▲]

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See detailLe système scolaire luxembourgeois: Un système scolaire scolaire peu efficace malgré ou à cause de son caractère multilingue?
Portante, Dominique UL; Martin, Romain UL

in Cahiers du Service de Pédagogie Expérimentale (SPE) (2003), 15/16(4), 516-532

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See detailSystèmes de numération en base rationnelle
Leroy, Julien UL

Presentation (2008, October)

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See detailA systemic approach to interpersonal relationships and activities among French teleworkers
Vayre, Emilie; Pignault, Anne UL

in New Technology, Work and Employment (2014), 29(2), 177-192

Within a systemic and interactional approach, this study seeks to understand how French teleworkers (re)organise their relationships with others as well as their activities. Lexical analysis of interviews ... [more ▼]

Within a systemic and interactional approach, this study seeks to understand how French teleworkers (re)organise their relationships with others as well as their activities. Lexical analysis of interviews with 24 telecommuters (nomadic, alternating and working at home full-time) confirms and complements the results in the literature in this field. On one hand, the findings confirmed a decline in the quality of professional relationships due to their being mediated through technology. On the other hand, there was a distinction between the ways in which different types of teleworkers ascribed meaning and adapted their activities and business, family and social relationships. [less ▲]

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See detailSystemic network analysis identifies XIAP and IkappaBalpha as potential drug targets in TRAIL resistant BRAF mutated melanoma.
Del Mistro, Greta; Lucarelli, Philippe UL; Muller, Ines et al

in NPJ systems biology and applications (2018), 4

Metastatic melanoma remains a life-threatening disease because most tumors develop resistance to targeted kinase inhibitors thereby regaining tumorigenic capacity. We show the 2nd generation hexavalent ... [more ▼]

Metastatic melanoma remains a life-threatening disease because most tumors develop resistance to targeted kinase inhibitors thereby regaining tumorigenic capacity. We show the 2nd generation hexavalent TRAIL receptor-targeted agonist IZI1551 to induce pronounced apoptotic cell death in mutBRAF melanoma cells. Aiming to identify molecular changes that may confer IZI1551 resistance we combined Dynamic Bayesian Network modelling with a sophisticated regularization strategy resulting in sparse and context-sensitive networks and show the performance of this strategy in the detection of cell line-specific deregulations of a signalling network. Comparing IZI1551-sensitive to IZI1551-resistant melanoma cells the model accurately and correctly predicted activation of NFkappaB in concert with upregulation of the anti-apoptotic protein XIAP as the key mediator of IZI1551 resistance. Thus, the incorporation of multiple regularization functions in logical network optimization may provide a promising avenue to assess the effects of drug combinations and to identify responders to selected combination therapies. [less ▲]

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See detailSystemic Operational Risk − Spillover Effects of Large Operational Losses in the European Banking Industry
Kaspereit, Thomas UL; Lopatta, Kerstin UL; Pakhchanyan, Suren et al

in Journal of Risk Finance (2017), 18(3),

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See detailA systemic transcriptome analysis reveals the regulation of neural stem cell maintenance by an E2F1-miRNA feedback loop.
Palm, Thomas; Hemmer, Kathrin; Winter, Julia et al

in Nucleic Acids Research (2013), 41(6), 3699-712

Stem cell fate decisions are controlled by a molecular network in which transcription factors and miRNAs are of key importance. To systemically investigate their impact on neural stem cell (NSC ... [more ▼]

Stem cell fate decisions are controlled by a molecular network in which transcription factors and miRNAs are of key importance. To systemically investigate their impact on neural stem cell (NSC) maintenance and neuronal commitment, we performed a high-throughput mRNA and miRNA profiling and isolated functional interaction networks of involved mechanisms. Thereby, we identified an E2F1-miRNA feedback loop as important regulator of NSC fate decisions. Although E2F1 supports NSC proliferation and represses transcription of miRNAs from the miR-17 approximately 92 and miR-106a approximately 363 clusters, these miRNAs are transiently up-regulated at early stages of neuronal differentiation. In these early committed cells, increased miRNAs expression levels directly repress E2F1 mRNA levels and inhibit cellular proliferation. In mice, we demonstrated that these miRNAs are expressed in the neurogenic areas and that E2F1 inhibition represses NSC proliferation. The here presented data suggest a novel interaction mechanism between E2F1 and miR-17 approximately 92 / miR-106a approximately 363 miRNAs in controlling NSC proliferation and neuronal differentiation. [less ▲]

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See detailSystemisches und räumliches Denken in der geographischen Bildung. Erste Ergebnisse zur Überprüfung eines Modells der Geographischen Systemkompetenz
Viehrig, K.; Siegmund, A.; Wüstenberg, Sascha UL et al

in Hüttermann, A.; Kirchner, P.; Schuler, S. (Eds.) et al Räumliche Orientierung: Räumliche Orientierung, Karten und Geoinformation im Unterricht (2012)

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See detailSystems analysis of transcription factor activities in environments with stable and dynamic oxygen concentrations
Rolfe, MD; Ocone, A; Stapleton, MR et al

in Open Biology (2012), 2(7), 120091

Understanding gene regulation requires knowledge of changes in transcription factor (TF) activities. Simultaneous direct measurement of numerous TF activities is currently impossible. Nevertheless ... [more ▼]

Understanding gene regulation requires knowledge of changes in transcription factor (TF) activities. Simultaneous direct measurement of numerous TF activities is currently impossible. Nevertheless, statistical approaches to infer TF activities have yielded non-trivial and verifiable predictions for individual TFs. Here, global statistical modelling identifies changes in TF activities from transcript profiles of Escherichia coli growing in stable (fixed oxygen availabilities) and dynamic (changing oxygen availability) environments. A core oxygen-responsive TF network, supplemented by additional TFs acting under specific conditions, was identified. The activities of the cytoplasmic oxygen-responsive TF, FNR, and the membrane-bound terminal oxidases implied that, even on the scale of the bacterial cell, spatial effects significantly influence oxygen-sensing. Several transcripts exhibited asymmetrical patterns of abundance in aerobic to anaerobic and anaerobic to aerobic transitions. One of these transcripts, ndh, encodes a major component of the aerobic respiratory chain and is regulated by oxygen-responsive TFs ArcA and FNR. Kinetic modelling indicated that ArcA and FNR behaviour could not explain the ndh transcript profile, leading to the identification of another TF, PdhR, as the source of the asymmetry. Thus, this approach illustrates how systematic examination of regulatory responses in stable and dynamic environments yields new mechanistic insights into adaptive processes. [less ▲]

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See detailSystems approaches for transforming social practice: Design requirements
König, Ariane UL

in König, Ariane (Ed.) Sustainability Science: Key issues (2018)

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See detailSystems approaches to modelling pathways and networks
Pfau, Thomas UL; Christian, Nils UL; Ebenhöh, Oliver

in Briefings in Functional Genomics (2011), 10(5), 266-279

It has become commonly accepted that systems approaches to biology are of outstanding importance to gain understanding from the vast amount of data which is presently being generated by advancing high ... [more ▼]

It has become commonly accepted that systems approaches to biology are of outstanding importance to gain understanding from the vast amount of data which is presently being generated by advancing high-throughput technologies. The diversity of methods to model pathways and networks has significantly expanded over the past two decades. Modern and traditional approaches are equally important and recent activities aim at integrating the advantages of both. While traditional methods, based on differential equations, are useful to study the dynamics of small systems, modern constraint-based models can be applied to genome-scale systems, but are not able to capture dynamic features. Integrating different approaches is important to develop consistent theoretical descriptions encompassing various scales of biological information. The rapid progress of the field of theoretical systems biology, however, demonstrates how our fundamental theoretical understanding of biology is gaining momentum. The scientific community has apparently accepted the challenge to truly understand the principles of life. [less ▲]

Detailed reference viewed: 39 (3 UL)