Convexity theories 0 fin. foundations

In this paper we study big convexity theories, that is convexity theories that are not necessarily bounded. As in the bounded case (see \cite{4}) such a convexity theory $\Gamma$ gives rise to the category \Gamma{\Cal C} of (left) $\Gamma$-convex modules. This is an equationally presentable category, and we prove that it is indeed an algebraic category over {\Cal S}et. We also introduce the category \Gamma{\Cal A}lg of $\Gamma$-convex algebras and show that the category {\Cal F}rm of frames is isomorphic to the category of associative, commutative, idempotent $\Bbb D^U$-convex algebras satisfying additional conditions, where $\Bbb D$ is the two-element semiring that is not a ring. Finally a classification of the convexity theories over $\Bbb D$ and a description of the categories of their convex modules is given

Temozolomidsensitivität von Tumorstammzellen im humanen Glioblastom

Eine kleine Gruppe von Tumorstammzellen ist in Glioblastomen für die Aufrechterhaltung des Tumorwachstums verantwortlich. Eine häufig formulierte Hypothese lautet, dass sich die Tumorrezidive auf Grund der verminderten Empfindlichkeit von Tumorstammzellen auf etablierte Therapien bilden. Unklar ist bislang jedoch, inwieweit Temozolomid (Temodal®) tatsächlich wirksam gegen diese Subpopulation ist. Hierzu untersuchte ich fünf verschiedene, aus primären Glioblastomen gewonnene Tumorstammzelllinien. Temozolomid hatte auch in hohen Dosen eine nur sehr geringe Toxizität auf die Gesamtheit aller Zellen. Im Gegensatz hierzu zeigte sich eine signifikant stärkere dosis- und zeitabhängige Abnahme der CD133+ Zellpopulation. In gleicher Weise induzierte Temozolomid dosisabhängig den selektiven Zelltod von Zellen mit Expression des Stammzellmarkers Nestin während Zellen mit Expression von Differenzierungsmarkern (β-III Tubulin, GFAP, GalC) vom Temozolomid-induzierten Zelltod geringer betroffen waren. Parallel zur verminderten Expression von Stammzellmarkern verminderte Temozolomid die Anzahl der in vitro zur Sphärenbildung befähigten Zellen, nachgewiesen im sog. minimal dilution assay, einen häufig verwendeten Assay zur Bestimmung des Stammzellanteils innerhalb einer Zellkultur. Interessanter Weise zeigten mittels FACS aufgereinigte CD133± Zellen keinen signifikanten Unterschied in der Temozolomidempfindlichkeit, als ursächlich hierfür stellte sich eine rasche Differenzierung der CD133+ Tumorstammzellen in CD133- Zellen heraus. Zusammenfassend zeigten die bisherigen Daten, dass Tumorstammzellen im Glioblastom entgegen meinen Erwartungen eine höhere Empfindlichkeit gegenüber Temozolomid als Tumorzellen ohne Stammzelleigenschaften besitzen. Dies lässt vermuten, dass durch eine Optimierung der aktuellen Temozolomid Dosierungsschemata die Wirksamkeit der Therapie auf Tumorstammzellen signifikant gesteigert und damit das Überleben der Patienten verbessert werden kann

TrackAgent: 6D Object Tracking via Reinforcement Learning

Tracking an object's 6D pose, while either the object itself or the observing camera is moving, is important for many robotics and augmented reality applications. While exploiting temporal priors eases this problem, object-specific knowledge is required to recover when tracking is lost. Under the tight time constraints of the tracking task, RGB(D)-based methods are often conceptionally complex or rely on heuristic motion models. In comparison, we propose to simplify object tracking to a reinforced point cloud (depth only) alignment task. This allows us to train a streamlined approach from scratch with limited amounts of sparse 3D point clouds, compared to the large datasets of diverse RGBD sequences required in previous works. We incorporate temporal frame-to-frame registration with object-based recovery by frame-to-model refinement using a reinforcement learning (RL) agent that jointly solves for both objectives. We also show that the RL agent's uncertainty and a rendering-based mask propagation are effective reinitialization triggers.Comment: International Conference on Computer Vision Systems (ICVS) 202

Differential basolateral–apical distribution of scavenger receptor, class B, type I in cultured cells and the liver

The high-density lipoprotein (HDL) receptor, scavenger receptor class B, type I (SR-BI), mediates selective cholesteryl ester uptake into the liver, which finally results in cholesterol secretion into the bile. Despite several reports, the distribution of hepatic SR-BI between the sinusoidal and canalicular membranes is still under debate. We present immunohistological data using specific markers showing that the bulk of SR-BI is present in sinusoidal membranes and, to a lesser extent, in canalicular membranes in murine and human liver sections. In addition, SR-BI was detected in preparations of rat liver canalicular membranes. We also compared the in vivo findings to HepG2 cells, a widely used in vitro hepatocyte model. Interestingly, SR-BI was enriched in bile canalicular-like (BC-like) structures in polarized HepG2 cells, which were cultivated either conventionally to form a monolayer or in Matrigel to form three-dimensional structures. Fluorescently labeled HDL was transported into close proximity of BC-like structures, whereas HDL labeled with the fluorescent cholesterol analog BODIPY-cholesterol was clearly detected within these structures. Importantly, similarly to human and mouse liver, SR-BI was localized in basolateral membranes in three-dimensional liver microtissues from primary human liver cells. Our results demonstrate that SR-BI is highly enriched in sinusoidal membranes and is also found in canalicular membranes. There was no significant basolateral–apical redistribution of hepatic SR-BI in fasting and refeeding experiments in mice. Furthermore, in vitro studies in polarized HepG2 cells showed explicit differences as SR-BI was highly enriched in BC-like structures. These structures are, however, functional and accumulated HDL-derived cholesterol. Thus, biological relevant model systems should be employed when investigating SR-BI distribution in vitro. Electronic supplementary material The online version of this article (doi:10.1007/s00418-014-1251-9) contains supplementary material, which is available to authorized users

Variety of idempotents in nonassociative algebras

In this paper, we study the variety of all nonassociative (NA) algebras from the idempotent point of view. We are interested, in particular, in the spectral properties of idempotents when algebra is generic, i.e. idempotents are in general position. Our main result states that in this case, there exist at least $n-1$ nontrivial obstructions (syzygies) on the Peirce spectrum of a generic NA algebra of dimension $n$. We also discuss the exceptionality of the eigenvalue $\lambda=\frac12$ which appears in the spectrum of idempotents in many classical examples of NA algebras and characterize its extremal properties in metrised algebras.Comment: 27 pages, 1 figure, submitte

An inverse Sturm-Liouville problem with a fractional derivative

In this paper, we numerically investigate an inverse problem of recovering the potential term in a fractional Sturm-Liouville problem from one spectrum. The qualitative behaviors of the eigenvalues and eigenfunctions are discussed, and numerical reconstructions of the potential with a Newton method from finite spectral data are presented. Surprisingly, it allows very satisfactory reconstructions for both smooth and discontinuous potentials, provided that the order $\alpha\in(1,2)$ of fractional derivative is sufficiently away from 2.Comment: 16 pages, 6 figures, accepted for publication in Journal of Computational Physic

Immune cell populations and cytokine production in spleen and mesenteric lymph nodes after laparoscopic surgery versus conventional laparotomy in mice

Purpose: There is evidence that open as well as minimally invasive abdominal surgery impair post-operative innate and acquired immune function. To compare the impact of these approaches as well as the one of different peritoneal gas exposures on immune function, we investigated cellular as well as cytokine-based immune parameters in mesenteric lymph nodes and the spleen postoperatively. Methods: Mice (n=26) were randomly assigned to the 4 study groups: (1) sham controls undergoing anesthesia alone, (2) laparotomy, and (3) air, or (4) carbon dioxide pneumoperitoneum. Mice were sacrificed 48h after the intervention, and their spleens and mesenteric lymph nodes were harvested. Cytokine production (TNF-α, IL-6, IL-10, and IFN-γ), splenic T cell subpopulations (cytotoxic T cells, T helper cells, and regulatory T cells) were analyzed. Results: TNF-α production of splenocytes 16h after ex vivo lipopolysaccharides (LPS) stimulation was significantly increased in the laparotomy group compared to all other groups. In contrast, TNF-α production of lymph node cells and IL-6 production of splenocytes after ex vivo LPS stimulation did not differ significantly between the groups. The numbers of regulatory T cells (Treg) in the spleen differed between groups. A significant reduction in Treg cell frequency was detected in the CO2 insufflation group compared to the laparotomy and the air insufflation group. Conclusion: Our findings demonstrate a distinct difference in immune effector functions and cellular composition of the spleen with regard to splenic TNF-α production and increased numbers of Treg cells in the spleen. These findings are in line with a higher peritoneal inflammatory status consequent to peritoneal air rather than CO2 exposure. Treg turned out to be key modulators of postoperative dysfunction of acquired immunit

Interference Effects between Three Coupled Bose-Einstein Condensates

We study the interference effects between three weakly linked trapped Bose-Einstein condensates (BEC) as a generalization of the two-component condensates. Three coupled Gross-Pitaevskii equations (GPE) are used to describe the dynamics of the system. The nonsinusoidal oscillation is found as a generalization of the Josephson effect in superconductivity. The self-trapped effects are also predicted in three coupled BEC. Moreover, in general case, the phase diagrams of the system are closed only for some special parameters, which can be used to determine the interaction parameters between atoms in BEC.Comment: 4 figure