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See detailSpectrum Sensing in Dual Polarized Fading Channels for Cognitive SatComs
Sharma, Shree Krishna UL; Chatzinotas, Symeon UL; Ottersten, Björn UL

in Proceedings of IEEE Globecom Conference 2012 (2012, December)

Next generation networks are moving towards the convergence of mobile, fixed and broadcasting services in one standard platform, which requires the co-existence of satellite and terrestrial networks in ... [more ▼]

Next generation networks are moving towards the convergence of mobile, fixed and broadcasting services in one standard platform, which requires the co-existence of satellite and terrestrial networks in the same spectrum. This framework has motivated the concept of cognitive Satellite Communication (SatComs). In this aspect, the problem of exploiting Spectrum Sensing (SS) techniques for a dual polarized fading channel is considered. In this paper, the performance of Energy Detection (ED) technique is evaluated in the context of a co-existence scenario of a satellite and a terrestrial link. Diversity combining techniques such as Equal Gain Combining (EGC) and Selection Combining (SC) are considered to enhance the SS efficiency. Furthermore, analytical expressions for probability of detection (Pd) and probability of false alarm (Pf ) are presented for these techniques in the considered fading channel and the sensing performance is studied through analytical and simulation results. Moreover, the effect of Cross Polar Discrimination (XPD) on the sensing performance is presented and it is shown that SS efficiency improves for low XPD. [less ▲]

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See detailSpectrum Sharing in Hybrid Terrestrial-Satellite Backhaul Networks in the Ka Band
Artiga, Xavier; Vázquez, Miguel Ángel; Pérez-Neira, Ana et al

in European Conference on Networks and Communications (EuCNC), June 2017 (2017, June)

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See detailThe speech and language therapist’s role in differential diagnosis
Deroey, Katrien UL

Bachelor/master dissertation (2004)

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See detailSpeech Based Estimation of Parkinson’s Disease Using Gaussian Processes and Automatic Relevance Determination
Despotovic, Vladimir UL; Skovranek, Tomas; Schommer, Christoph UL

in Neurocomputing (2020), 401

Parkinson’s disease is a progressive neurodegenerative disorder often accompanied by impairment in articulation, phonation, prosody and fluency of speech. In fact, speech impairment is one of the earliest ... [more ▼]

Parkinson’s disease is a progressive neurodegenerative disorder often accompanied by impairment in articulation, phonation, prosody and fluency of speech. In fact, speech impairment is one of the earliest Parkinson’s disease symptoms, and may be used for early diagnosis. We present an experimental study of identification of Parkinson’s disease and assessment of disease progress from speech using Gaussian processes, which is further combined with Automatic Relevance Determination (ARD) for efficient feature selection. Hyperparameters of ARD covariance functions are learned for each individual feature; therefore, can be used for evaluation of their importance. In that way only a small subset of highly relevant acoustic features is selected, leading to models with better performance and lower complexity. The performance of the proposed method was assessed on two datasets: Parkinson’s disease detection dataset, which contains a range of biomedical voice measurements obtained from 31 subjects, 23 of them suffering from Parkinson’s disease and 8 healthy subjects; and Parkinson’s telemonitoring dataset, containing biomedical voice measurements collected from 42 Parkinson’s disease patients for estimation of the disease progress. Gaussian process classification with automatic relevance determination is able to successfully discriminate between Parkinson’s disease patients and healthy controls with 96.92% accuracy, outperforming Support Vector Machines and decision tree ensembles (random forests, boosted and bagged decision trees). The usability of Gaussian processes is further confirmed in regression task for tracking the progress of the disease. [less ▲]

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See detailSpeeding up Collision Search for Byte-Oriented Hash Functions
Khovratovich, Dmitry UL; Biryukov, Alex UL; Nikolic, Ivica UL

in CT-RSA (2009)

We describe a new tool for the search of collisions for hash functions. The tool is applicable when an attack is based on a differential trail, whose probability determines the complexity of the attack ... [more ▼]

We describe a new tool for the search of collisions for hash functions. The tool is applicable when an attack is based on a differential trail, whose probability determines the complexity of the attack. Using the linear algebra methods we show how to organize the search so that many (in some cases — all) trail conditions are always satisfied thus significantly reducing the number of trials and the overall complexity. The method is illustrated with the collision and second preimage attacks on the compression functions based on Rijndael. We show that slow diffusion in the Rijndael (and AES) key schedule allows to run an attack on a version with a 13-round compression function, and the S-boxes do not prevent the attack. We finally propose how to modify the key schedule to resist the attack and provide lower bounds on the complexity of the generic differential attacks for our modification. [less ▲]

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See detailSpeeding-Up Mutation Testing via Data Compression and State Infection
Zhu, Qianqian; Panichella, Annibale UL; Zaidman, Andy

in IEEE International Conference on Software Testing, Verification and Validation Workshops (ICSTW) 2017 (2017, March 13)

Mutation testing is widely considered as a high-end test criterion due to the vast number of mutants it generates. Although many efforts have been made to reduce the computational cost of mutation testing ... [more ▼]

Mutation testing is widely considered as a high-end test criterion due to the vast number of mutants it generates. Although many efforts have been made to reduce the computational cost of mutation testing, its scalability issue remains in practice. In this paper, we introduce a novel method to speed up mutation testing based on state infection information. In addition to filtering out uninfected test executions, we further select a subset of mutants and a subset of test cases to run leveraging data-compression techniques. In particular, we adopt Formal Concept Analysis (FCA) to group similar mutants together and then select test cases to cover these mutants. To evaluate our method, we conducted an experimental study on six open source Java projects. We used EvoSuite to automatically generate test cases and to collect mutation data. The initial results show that our method can reduce the execution time by 83.93% with only 0.257% loss in precision. [less ▲]

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See detailSpeedy assessment of speeded reasoning with the intelligence screening „mini-q“.
Baudson, Tanja Gabriele UL; Kaufmann, M.; Preckel, F. et al

Scientific Conference (2015)

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See detailSpeer und Er. Und Wir? Deutsche Geschichte in gebrochener Erinnerung
Krebs, Stefan UL; Tschacher, Werner

in Geschichte in Wissenschaft und Unterricht (2007), 58(3), 163-173

Warum ist Albert Speer auch heute noch als der „gute Nazi“ im kollektiven Gedächtnis der Bundesrepublik verankert? Ausgehend von der Kontroverse um die Anwesenheit Speers bei der Posener Gauleitertagung ... [more ▼]

Warum ist Albert Speer auch heute noch als der „gute Nazi“ im kollektiven Gedächtnis der Bundesrepublik verankert? Ausgehend von der Kontroverse um die Anwesenheit Speers bei der Posener Gauleitertagung im Oktober 1943 zeichnet der Aufsatz das Ringen geschichtspolitischer Akteure um die Interpretation der NS-Vergangenheit nach. Dabei wird sichtbar, dass in den letzten Jahrzehnten die historische Forschung den Mythos Speer zerstört und ein neues Bild der Nationalsozialisten gezeichnet hat, aber in den Massenmedien weiterhin überkommene Deutungsmuster des „Dritten Reiches“ überdauern. [less ▲]

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See detailDas Speichern von Zwischenlösungen. Ein potentieller Moderator für den Zusammenhang zwischen Arbeitsgedächtniskapazität und der Leistung in figuralen Matrizenaufgaben.
Krieger, Florian UL; Becker, Nicolas; Zimmer, Hubert D. et al

Scientific Conference (2015, May)

Theoretische Ansätze sehen die Anzahl der Regeln in einer Matrizenaufgabe als eine der Determinanten für die Belastung des Arbeitsgedächtnisses. Eine mögliche Ursache könnte das Speichern von Teillösungen ... [more ▼]

Theoretische Ansätze sehen die Anzahl der Regeln in einer Matrizenaufgabe als eine der Determinanten für die Belastung des Arbeitsgedächtnisses. Eine mögliche Ursache könnte das Speichern von Teillösungen bei Matrizenaufgaben mit mehreren Regeln sein. In der vorliegenden Studie wurde untersucht, ob Personen mit einer hohen Arbeitsgedächtniskapazität durch das Speichern von Teillösungen bei der Lösung von Matrizenaufgaben profitieren. Hierzu wurde in einem Innerhalb-Design den Testpersonen (N=84) eine Matrizentestversion präsentiert, bei der das Arbeitsgedächtnis belastet werden sollte, indem die Teillösungen vor der Eingabe mental aufrechterhalten werden mussten. Zudem wurde eine Version präsentiert, in der Teillösungen direkt eingegeben werden konnten, was zu einer Entlastung des Arbeitsgedächtnisses führen sollte. Beide Matrizentestversionen zeigen einen moderaten Zusammenhang mit der Arbeitsgedächtniskapazität. Allerdings zeigen sich keine Unterschiede zwischen den beiden Korrelationen, was als Evidenz gewertet werden kann, dass das Speichern von Teillösungen keinen bedeutsamen Moderator für den Zusammenhang von Arbeitsgedächtniskapazität und der Leistung in einem Matrizentest darstellt. [less ▲]

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See detailDas Spektrum der elektromagnetischen Strahlung: Technische Nutzung und Herausforderungen
Marso, Michel UL

in Revue Technique Luxembourgeoise (2009), (4), 36-37

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See detailspellux – Automatic text normalization for Luxembourgish
Purschke, Christoph UL

Software (2020)

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See detailSperm phenotype of mice carrying a gene deletion for the plasma membrane calcium/calmodulin dependent ATPase 4.
Withers, Sarah; Cartwright, Elizabeth J.; Neyses, Ludwig UL

in Molecular and cellular endocrinology (2006), 250(1-2), 93-7

The sarcolemmal calcium pumps (PMCA for plasma membrane calcium/calmodulin dependent ATPase) are a family of 10 transmembrane domain proteins ejecting calcium from the cytosol. They are encoded by four ... [more ▼]

The sarcolemmal calcium pumps (PMCA for plasma membrane calcium/calmodulin dependent ATPase) are a family of 10 transmembrane domain proteins ejecting calcium from the cytosol. They are encoded by four independent genes and at least 21 splice variants have been described. Isoforms 1 and 4 are ubiquitous, whereas isoforms 2 and 3 are confined to neurons and few other cells (e.g. isoform 2 in the myocardium). In non-excitable cells they are thought to be the only calcium ejection systems and their function as governors of calcium balance is hence intuitive since cells cannot survive in a state of calcium overload. Differences in the affinity of the various isoforms for calcium, ATP and calmodulin have been described, but it is unclear whether the pumps have specialized functions over and above their 'housekeeping' role. In particular, in excitable cells, most calcium is ejected by the sodium/calcium exchanger suggesting that the PMCAs may have evolved into a specialized role. Recently, our group has identified a number of specialized functions of the PMCAs, notably a prominent regulatory role of PMCA4 (splice variant b) for neuronal NO synthase as well as for the Ras pathway. In addition, mice carrying a genetic deletion of the PMCA4 gene showed normal female, but completely infertile male animals. This is due to a highly specific defect in sperm motility, which is reduced to zero, with normal fertilization capacity. Overall, a scenario emerges where the plasma membrane calcium pumps fulfil roles far beyond the traditional housekeeping function, notably in cell signaling, sperm motility, and potentially in cell division. Consequently, we are currently exploring their potential as future drug targets for a variety of conditions, as well as their potential use in the development of a male contraception. [less ▲]

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See detailSpezialsprachen: Fachsprachen, Wissenschaftssprachen
Sieburg, Heinz UL

in Dembeck, Till; Parr, Rolf (Eds.) Literatur und Mehrsprachigkeit. Ein Handbuch (2017)

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See detailSpezifität der Körperbildstörung für Anorexia nervosa
Rost, Silke UL; Jaite, Charlotte; Sarrar, Lea et al

Poster (2013, May 10)

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See detailSpezifität der Körperbildstörung für Anorexia nervosa
Rost, Silke UL; Jaite, Charlotte; Sarrar, Lea et al

Scientific Conference (2013, March 09)

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See detailSpherical CR Dehn surgeries
Acosta, Miguel UL

in Pacific Journal of Mathematics (2016), 284(2), 257-282

Consider a three dimensional cusped spherical CR manifold M and suppose that the holonomy representation of $\pi_1(M)$ can be deformed in such a way that the peripheral holonomy is generated by a non ... [more ▼]

Consider a three dimensional cusped spherical CR manifold M and suppose that the holonomy representation of $\pi_1(M)$ can be deformed in such a way that the peripheral holonomy is generated by a non-parabolic element. We prove that, in this case, there is a spherical CR structure on some Dehn surgeries of M. The result is very similar to R. Schwartz's spherical CR Dehn surgery theorem, but has weaker hypotheses and does not give the uniformizability of the structure. We apply our theorem in the case of the Deraux-Falbel structure on the Figure Eight knot complement and obtain spherical CR structures on all Dehn surgeries of slope $-3 + r$ for $r \in \mathbb{Q}^{+}$ small enough. [less ▲]

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See detailSpherical CR uniformization of Dehn surgeries of the Whitehead link complement
Acosta, Miguel UL

in Geometry and Topology (2019), 23(5), 25932664

We apply a spherical CR Dehn surgery theorem in order to obtain infinitely many Dehn surgeries of the Whitehead link complement that carry spherical CR structures. We consider as a starting point the ... [more ▼]

We apply a spherical CR Dehn surgery theorem in order to obtain infinitely many Dehn surgeries of the Whitehead link complement that carry spherical CR structures. We consider as a starting point the spherical CR uniformization of the Whitehead link complement constructed by Parker and Will, using a Ford domain in the complex hyperbolic plane H2C. We deform the Ford domain of Parker and Will in H2C in a one-parameter family. On one side, we obtain infinitely many spherical CR uniformizations on a particular Dehn surgery on one of the cusps of the Whitehead link complement. On the other side, we obtain spherical CR uniformizations for infinitely many Dehn surgeries on the same cusp of the Whitehead link complement. These manifolds are parametrized by an integer n≥4, and the spherical CR structure obtained for n=4 is the Deraux–Falbel spherical CR uniformization of the figure eight knot complement. [less ▲]

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See detailSphingolipid-mediated inflammatory signaling leading to autophagy inhibition converts erythropoiesis to myelopoiesis in human hematopoietic stem/progenitor cells
Orsini, Marion; Chateauvieux, Sebastien; Rhim, Jiyun et al

in Cell Death and Differentiation (2019), 26(9), 17961812

Elevated levels of the pro-inflammatory cytokine tumor necrosis factor-α (TNFα) inhibit erythropoiesis and cause anemia in patients with cancer and chronic inflammatory diseases. TNFα is also a potent ... [more ▼]

Elevated levels of the pro-inflammatory cytokine tumor necrosis factor-α (TNFα) inhibit erythropoiesis and cause anemia in patients with cancer and chronic inflammatory diseases. TNFα is also a potent activator of the sphingomyelinase (SMase)/ceramide pathway leading to ceramide synthesis and regulating cell differentiation, proliferation, apoptosis, senescence, and autophagy. Here we evaluated the implication of the TNFα/SMase/ceramide pathway on inhibition of erythropoiesis in human CD34+ hematopoietic stem/progenitor cells (CD34/HSPCs) from healthy donors. Exogenous synthetic C2- and C6-ceramide as well as bacterial SMase inhibited erythroid differentiation in erythropoietin-induced (Epo)CD34/HSPCs shown by the analysis of various erythroid markers. The neutral SMase inhibitor GW4869 as well as the genetic inhibition of nSMase with small interfering RNA (siRNA) against sphingomyelin phosphodiesterase 3 (SMPD3) prevented the inhibition by TNFα, but not the acid SMase inhibitor desipramine. Moreover, sphingosine-1-phosphate (S1P), a ceramide metabolite, restored erythroid differentiation, whereas TNFα inhibited sphingosine kinase-1, required for S1P synthesis. Analysis of cell morphology and colony formation demonstrated that erythropoiesis impairment was concomitant with a granulomonocytic differentiation in TNFα- and ceramide-treated EpoCD34/HSPCs. Inhibition of erythropoiesis and induction of granulomonocytic differentiation were correlated to modulation of hematopoietic transcription factors (TFs) GATA-1, GATA-2, and PU.1. Moreover, the expression of microRNAs (miR)-144/451, miR-146a, miR-155, and miR-223 was also modulated by TNFα and ceramide treatments, in line with cellular observations. Autophagy plays an essential role during erythropoiesis and our results demonstrate that the TNFα/neutral SMase/ceramide pathway inhibits autophagy in EpoCD34/HSPCs. TNFα- and ceramide-induced phosphorylation of mTORS2448 and ULK1S758, inhibited Atg13S355 phosphorylation, and blocked autophagosome formation as shown by transmission electron microscopy and GFP-LC3 punctae formation. Moreover, rapamycin prevented the inhibitory effect of TNFα and ceramides on erythropoiesis while inhibiting induction of myelopoiesis. In contrast, bafilomycin A1, but not siRNA against Atg5, induced myeloid differentiation, while both impaired erythropoiesis. We demonstrate here that the TNFα/neutral SMase/ceramide pathway inhibits erythropoiesis to induce myelopoiesis via modulation of a hematopoietic TF/miR network and inhibition of late steps of autophagy. Altogether, our results reveal an essential role of autophagy in erythroid vs. myeloid differentiation. [less ▲]

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See detailSphingosine kinases regulate NOX2 activity via p38 MAPK-dependent translocation of S100A8/A9
Schenten, Véronique UL; Melchior, Chantal UL; Steinckwich, Nathalie et al

in Journal of Leukocyte Biology (2011), 89(4), 587-596

Neutrophils play a fundamental role in host defense by neutralizing pathogens through the generation of ROS by NOX2. In nonexcitable cells, Ca(2+) influx is essentially mediated via SOCE, a complex ... [more ▼]

Neutrophils play a fundamental role in host defense by neutralizing pathogens through the generation of ROS by NOX2. In nonexcitable cells, Ca(2+) influx is essentially mediated via SOCE, a complex mechanism in which depletion of intracellular Ca(2+) stores from the ER results in Ca(2+) entry through Ca(2+) SOCs at the plasma membrane. In this regard, it is well established that extracellular Ca(2+) entry participates to NOX2 activation. S1P, produced by SphKs, has been involved in Ca(2+) homeostasis and thus, could intervene in NOX2 regulation. The aim of this study was to characterize the importance of SphKs in NOX2 activation and the signaling cascade involved in this mechanism. Treatment of neutrophil-like dHL-60 cells by DHS, a SphK inhibitor, and SphK siRNA inhibited fMLF-induced NOX2 activity. Sequential activation of cells by thapsigargin and the phorbol ester PMA revealed that SphK-regulated NOX2 activity relies on intracellular Ca(2+) store depletion. Confocal microscopy and immunoblot analysis showed that stimulation by thapsigargin and PMA mediated S100A8/A9 recruitment to the plasma membrane and p38 MAPK activation. S100A8/A9 translocation decreased when SphK activity was blocked. This result was confirmed in purified human neutrophils, which were physiologically stimulated by fMLF. In addition, p38 MAPK was found to be regulated by SphKs. These results define a pathway leading to NOX2 activation, in which p38 MAPK-mediated S100A8/A9 translocation is regulated by Ca(2+) store depletion-dependent SphK activation. [less ▲]

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See detailSpiel in der Grundschule: Multiple Funktionen - maßgebliche Aufgaben
Andersen, Katja Natalie UL; Schwander, Michael Wolfgang

Book published by Klinkhardt (2005)

Detailed reference viewed: 90 (3 UL)