576 research outputs found
From coupled elementary units to the complexity of the glass transition
Supercooled liquids display fascinating properties upon cooling such as the
emergence of dynamic length scales. Different models strongly vary with respect
to the choice of the elementary subsystems (CRR) as well as their mutual
coupling. Here we show via computer simulations of a glass former that both
ingredients can be identified via analysis of finite-size effects within the
continuous-time random walk framework. The CRR already contain complete
information about thermodynamics and diffusivity whereas the coupling
determines structural relaxation and the emergence of dynamic length scales
How Does the Past of a Soccer Match Influence Its Future? Concepts and Statistical Analysis
Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified.
Soccer: is scoring goals a predictable Poissonian process?
The non-scientific event of a soccer match is analysed on a strictly
scientific level. The analysis is based on the recently introduced concept of a
team fitness (Eur. Phys. J. B 67, 445, 2009) and requires the use of
finite-size scaling. A uniquely defined function is derived which
quantitatively predicts the expected average outcome of a soccer match in terms
of the fitness of both teams. It is checked whether temporary fitness
fluctuations of a team hamper the predictability of a soccer match.
To a very good approximation scoring goals during a match can be
characterized as independent Poissonian processes with pre-determined
expectation values. Minor correlations give rise to an increase of the number
of draws. The non-Poissonian overall goal distribution is just a consequence of
the fitness distribution among different teams. The limits of predictability of
soccer matches are quantified. Our model-free classification of the underlying
ingredients determining the outcome of soccer matches can be generalized to
different types of sports events
Semi-supervised Learning based on Distributionally Robust Optimization
We propose a novel method for semi-supervised learning (SSL) based on
data-driven distributionally robust optimization (DRO) using optimal transport
metrics. Our proposed method enhances generalization error by using the
unlabeled data to restrict the support of the worst case distribution in our
DRO formulation. We enable the implementation of our DRO formulation by
proposing a stochastic gradient descent algorithm which allows to easily
implement the training procedure. We demonstrate that our Semi-supervised DRO
method is able to improve the generalization error over natural supervised
procedures and state-of-the-art SSL estimators. Finally, we include a
discussion on the large sample behavior of the optimal uncertainty region in
the DRO formulation. Our discussion exposes important aspects such as the role
of dimension reduction in SSL
Notizen zu einer Diskussion ĂŒber den Tod
In dem Beitrag wird der Frage nachgegangen, wie sich die Zeitlichkeit des Lebens Ă€ndert, wenn der Tod akzeptiert, statt verdrĂ€ngt und geleugnet wird. Es wird zunĂ€chst gezeigt, was es heiĂt, den Tod zu akzeptieren. Vor dem Hintergrund, daĂ Tod und Trennung in einem Zusammenhang stehen, wird erlĂ€utert, daĂ Leben und Entwicklung nur dann möglich sind, wenn Trennungserlebnisse Fort-Schritte notwendig machen und in diesen Trennungserlebnissen das Getrennte aufgehoben ist. Trennungen werden als Voraussetzung gesehen, um neue Bindungen zu ermöglichen. In dieser Interpretation wird Sterben als die letzte Phase der Entwicklung eines Menschen betrachtet. VerdrĂ€ngung und Leugnung des Todes werden folglich als Konsequenz die Abwertung und das Exil des Sterbenden bedeuten. Es wird gezeigt, wie kulturelle und gesellschaftliche EinflĂŒsse den individuellen Tod bestimmen. Die Bedeutung des Todes in der Revolution wird diskutiert. Sterben wird als revolutionĂ€re Pflicht analysiert, die belohnt wird durch die Unsterblichkeit im GedĂ€chtnis der nachfolgenden Generationen. (RW
Learning Free-Form Deformations for 3D Object Reconstruction
Representing 3D shape in deep learning frameworks in an accurate, efficient
and compact manner still remains an open challenge. Most existing work
addresses this issue by employing voxel-based representations. While these
approaches benefit greatly from advances in computer vision by generalizing 2D
convolutions to the 3D setting, they also have several considerable drawbacks.
The computational complexity of voxel-encodings grows cubically with the
resolution thus limiting such representations to low-resolution 3D
reconstruction. In an attempt to solve this problem, point cloud
representations have been proposed. Although point clouds are more efficient
than voxel representations as they only cover surfaces rather than volumes,
they do not encode detailed geometric information about relationships between
points. In this paper we propose a method to learn free-form deformations (FFD)
for the task of 3D reconstruction from a single image. By learning to deform
points sampled from a high-quality mesh, our trained model can be used to
produce arbitrarily dense point clouds or meshes with fine-grained geometry. We
evaluate our proposed framework on both synthetic and real-world data and
achieve state-of-the-art results on point-cloud and volumetric metrics.
Additionally, we qualitatively demonstrate its applicability to label
transferring for 3D semantic segmentation.Comment: 16 pages, 7 figures, 3 table
Tracking System with Re-identification Using a RGB String Kernel
International audiencePeople re-identification consists to identify a person which comes back in a scene where it has been previously detected. This key problem in visual surveillance applications may concern single or multi camera systems. Features encoding each person should be rich enough to provide an efficient re-identification while being sufficiently robust to remain significant through the different phenomena which may alter the appearance of a person in a video. We propose in this paper a method which encodes people's appearance through a string of salient points. The similarity between two such strings is encoded by a kernel. This last kernel is combined with a tracking algorithm in order to associate a set of strings to each person and to measure similarities between persons entering into the scene and persons who left it
HLA-J, a Non-Pseudogene as a New Prognostic Marker for Therapy Response and Survival in Breast Cancer
The human leukocyte antigen (HLA) genes are cell-surface proteins, essential for immune cell interaction. HLA-G is known for their high immunosuppressive effect and its potential as predictive marker in breast cancer. However, nothing is known about the HLA-J and its immunosuppressive, prognostic and predictive features, as it is assumed to be a pseudogene by in silico sequence interpretation. HLA-J, ESR1, ERBB2, KRT5 and KRT20 mRNA expression were analysed in 29 fresh frozen breast cancer biopsies and their corresponding resectates obtained from patients treated with neoadjuvant chemotherapy (NACT). mRNA was analysed with gene specific TaqMan-based Primer/Probe sets and normalized to Calmodulin 2. All breast cancer samples did express HLA-J and frequently increased HLA-J mRNA levels after NACT. HLA-J mRNA was significantly associated with overexpression of the ESR1 mRNA status (Spearman Ï 0,5679; p = 0.0090) and KRT5 mRNA (Spearman Ï 0,6121; p = 0.0041) in breast cancer core biopsies and dominated in luminal B subtype. Kaplan Meier analysis revealed that an increase of HLA-J mRNA expression after NACT had worse progression free survival (p = 0,0096), indicating a counterreaction of tumor tissues presumably to prevent elimination by enhanced immune infiltration induced by NACT. This counterreaction is associated with worse prognosis. To our knowledge this is the first study identifying HLA-J as a new predictive marker in breast cancer being involved in immune evasion mechanisms.Humane Leukozyten-Antigene (HLA) sind Proteine auf der ZelloberflĂ€che, die essenziell fĂŒr die Immunzellinteraktion sind. HLA-G ist fĂŒr seine hohe immunosuppressive Wirkung sowie als potenzieller prĂ€dikativer Marker fĂŒr Brustkrebs bekannt. Dagegen ist kaum etwas ĂŒber HLA-J und seine immunosuppressiven, prognostischen und prĂ€diktiven Eigenschaften bekannt, da es basierend auf In-silico-Sequenzanalysen als âPseudogenâ interpretiert wurde. Die Expression von HLA-J, ESR1, ERBB2, KRT5 und KRT20 mRNA wurde in 29 frisch gefrorenen Brustkrebsbiopsien analysiert und mit den klinisch-pathologischen Daten von Patientinnen, welche mit neoadjuvanter Chemotherapie behandelt wurden, verglichen. Die mRNA-Expression wurde mit genspezifischen TaqMan-basierten Primer/Probe-Sets analysiert und auf Calmodulin 2 normalisiert. Alle Gewebeproben von Patientinnen mit Brustkrebs exprimierten HLA-J, und der HLA-J-mRNA-Spiegel war nach NACT oft erhöht. In den Brustkrebsstanzbiopsien war die HLA-J-mRNA-Expression signifikant mit der Ăberexpression von ESR1-mRNA (Spearmans Ï 0,5679; pâ=â0,0090) und KRT5-mRNA (Spearmans Ï 0,6121; pâ=â0,0041) assoziiert und dominierte im Luminal-B-Subtyp. Die Kaplan-Meier-Analyse zeigte, dass ein Anstieg der HLA-J-mRNA-Expression nach NACT mit einem schlechteren progressionsfreien Ăberleben einhergeht (pâ=â0,0096), womöglich als Gegenreaktion des Tumorgewebes, um eine Eliminierung durch tumorinfiltrierende Lymphozyten, welche durch eine NACT induziert wurden, zu verhindern. Diese Gegenreaktion ist mit einer schlechteren Prognose assoziiert. Soweit uns bekannt, handelt es sich hierbei um die erste Studie, die HLA-J als neuen prĂ€diktiven Marker im Brustkrebs identifiziert hat und möglicherweise zur Immunevasion beitrĂ€gt
Nutlin-3a-aa: Improving the Bioactivity of a p53/MDM2 Interaction Inhibitor by Introducing a Solvent-Exposed Methylene Group
Nutlin-3a is a reversible inhibitor of the p53/MDM2 interaction. We have synthesized the derivative Nutlin-3a-aa bearing an additional exocyclic methylene group in the piperazinone moiety. Nutlin-3a-aa is more active than Nutlin-3a against purified wild-type MDM2, and is more effective at increasing p53 levels and releasing transcription of p53 target genes from MDM2-induced repression. X-ray analysis of wild-type MDM2-bound Nutlin-3a-aa indicated that the orientation of its modified piperazinone ring was altered in comparison to the piperazinone ring of MDM2-bound Nutlin-3a, with the exocyclic methylene group of Nutlin-3a-aa pointing away from the protein surface. Our data point to the introduction of exocyclic methylene groups as a useful approach by which to tailor the conformation of bioactive molecules for improved biological activity.This work was generously supported by the Deutsche Forschungsgemeinschaft (BE 4572/3-1 to T.B.). We extend our thanks to Barbara KlĂŒver, Katrin Eckhardt, Nadiya Brovchenko, and Domenique Herbstritt for experimental support. Parts of the data described in this manuscript have been published in the dissertation of Florian Nietzold (Leipzig University, 2019).31 In addition, this work was financially supported by the National Science Centre, Poland (NCN) under Grant Symphony 2014/12/W/NZ1/00457 (to T.A.H). We thank HZB for the allocation of synchrotron radiation beamtime. We acknowledge the MCB Structural Biology Core Facility (supported by the TEAM TECH CORE FACILITY/2017-4/6 grant from the Foundation for Polish Science) for valuable support. Open Access funding enabled and organized by Projekt DEAL
Activated Polymorphonuclear Leukocytes Rapidly Synthesize Retinoic Acid Receptor-α: A Mechanism for Translational Control of Transcriptional Events
In addition to releasing preformed granular proteins, polymorphonuclear leukocytes (PMNs) synthesize chemokines and other factors under transcriptional control. Here we demonstrate that PMNs express an inducible transcriptional modulator by signal-dependent activation of specialized mechanisms that regulate messenger RNA (mRNA) translation. HL-60 myelocytic cells differentiated to surrogate PMNs respond to activation by platelet activating factor by initiating translation and with appearance of specific mRNA transcripts in polyribosomes. cDNA array analysis of the polyribosome fraction demonstrated that retinoic acid receptor (RAR)-α, a transcription factor that controls the expression of multiple genes, is one of the polyribosome-associated transcripts. Quiescent surrogate HL60 PMNs and primary human PMNs contain constitutive message for RAR-α but little or no protein. RAR-α protein is rapidly synthesized in response to platelet activating factor under the control of a specialized translational regulator, mammalian target of rapamycin, and is blocked by the therapeutic macrolide rapamycin, events consistent with features of the 5âČ untranslated region of the transcript. Newly synthesized RAR-α modulates production of interleukin-8. Rapid expression of a transcription factor under translational control is a previously unrecognized mechanism in human PMNs that indicates unexpected diversity in gene regulation in this critical innate immune effector cell
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