Search results for "Arrow"

Lifesaving Stenting of Pulmonary Arteries Critically Narrowed by Mediastinal Lymphoma

2019

Virtual and arrow Temperley–Lieb algebras, Markov traces, and virtual link invariants

2021

Let [Formula: see text] be the algebra of Laurent polynomials in the variable [Formula: see text] and let [Formula: see text] be the algebra of Laurent polynomials in the variable [Formula: see text] and standard polynomials in the variables [Formula: see text] For [Formula: see text] we denote by [Formula: see text] the virtual braid group on [Formula: see text] strands. We define two towers of algebras [Formula: see text] and [Formula: see text] in terms of diagrams. For each [Formula: see text] we determine presentations for both, [Formula: see text] and [Formula: see text]. We determine sequences of homomorphisms [Formula: see text] and [Formula: see text], we determine Markov traces […

Global functorial hypergestures over general skeleta for musical performance

2016

Musical performance theory using Lagrangian formalism, inspired by physical string theory, has been described in previous research. That approach was restricted to zero-addressed hypergestures of local character, and also to digraph skeleta of simple arrow type. In this article, we extend the theory to hypergestures that are defined functorially over general topological categories as addresses, are global, and are also defined for general skeleta. We also prove several versions of the important Escher Theorem for this general setup. This extension is highly motivated by theoretical and practical musical performance requirements of which we give concrete examples.

Entropy, Lyapunov exponents, and rigidity of group actions

2018

This text is an expanded series of lecture notes based on a 5-hour course given at the workshop entitled "Workshop for young researchers: Groups acting on manifolds" held in Teres\'opolis, Brazil in June 2016. The course introduced a number of classical tools in smooth ergodic theory -- particularly Lyapunov exponents and metric entropy -- as tools to study rigidity properties of group actions on manifolds. We do not present comprehensive treatment of group actions or general rigidity programs. Rather, we focus on two rigidity results in higher-rank dynamics: the measure rigidity theorem for affine Anosov abelian actions on tori due to A. Katok and R. Spatzier [Ergodic Theory Dynam. Systems…

Fluctuation theorems for non-Markovian quantum processes

2013

Exploiting previous results on Markovian dynamics and fluctuation theorems, we study the consequences of memory effects on single realizations of nonequilibrium processes within an open system approach. The entropy production along single trajectories for forward and backward processes is obtained with the help of a recently proposed classical-like non-Markovian stochastic unravelling, which is demonstrated to lead to a correction of the standard entropic fluctuation theorem. This correction is interpreted as resulting from the interplay between the information extracted from the system through measurements and the flow of information from the environment to the open system: Due to memory e…

PAR1 signaling regulates the retention and recruitment of EPCR-expressing bone marrow hematopoietic stem cells

2015

Retention of long-term repopulating hematopoietic stem cells (LT-HSCs) in the bone marrow is essential for hematopoiesis and for protection from myelotoxic injury. We report that signaling cascades that are traditionally viewed as coagulation related also control retention of endothelial protein C receptor-positive (EPCR(+)) LT-HSCs in the bone marrow and their recruitment to the blood via two pathways mediated by protease activated receptor 1 (PAR1). Thrombin-PAR1 signaling induces nitric oxide (NO) production, leading to EPCR shedding mediated by tumor necrosis factor-α-converting enzyme (TACE), enhanced CXCL12-CXCR4-induced motility and rapid stem and progenitor cell mobilization. Conver…

NMR relaxation times of trabecular bone—reproducibility, relationships to tissue structure and effects of sample freezing

2010

Nuclear magnetic resonance (NMR) spectroscopy provides a potential tool for non-invasive evaluation of the trabecular bone structure. The objective of this study was to determine the reproducibility of the NMR relaxation parameters (T(2), Carr-Purcel-T(2), T(1ρ)) for fat and water and relate those to the structural parameters obtained by micro-computed tomography (μCT). Especially, we aimed to evaluate the effect of freezing on the relaxation parameters. For storing bone samples, freezing is the standard procedure during which the biochemical and cellular organization of the bone marrow may be affected. Bovine trabecular bone samples were stored at -20 °C for 7 days and measured by NMR spec…

Neuroinflammation by cytotoxic T-lymphocytes impairs retrograde axonal transport in an oligodendrocyte mutant mouse.

2012

Mice overexpressing proteolipid protein (PLP) develop a leukodystrophy-like disease involving cytotoxic, CD8+ T-lymphocytes. Here we show that these cytotoxic T-lymphocytes perturb retrograde axonal transport. Using fluorogold stereotactically injected into the colliculus superior, we found that PLP overexpression in oligodendrocytes led to significantly reduced retrograde axonal transport in retina ganglion cell axons. We also observed an accumulation of mitochondria in the juxtaparanodal axonal swellings, indicative for a disturbed axonal transport. PLP overexpression in the absence of T-lymphocytes rescued retrograde axonal transport defects and abolished axonal swellings. Bone marrow tr…

Risk taking in natural predation risk gradients: support for risk allocation from breeding pied flycatchers

2011

Predation risk is vital in foraging decisions because activity involves some degree of risk. In a natural setting, predation risk shows temporal variation, which has been largely neglected in antipredator studies. We tested a prediction of the risk allocation hypothesis in which allocation to antipredator behaviours will depend on temporal variation in perceived risk. Individuals are predicted to allocate heightened antipredator behaviours to brief infrequent periods of high risk, but with increasing frequency of high-risk periods, individuals will invest less in these behaviours. We tested this prediction using pied flycatchers, Ficedula hypoleuca , breeding at different distances from spa…

MiR-29b antagonizes the pro-inflammatory tumor-promoting activity of multiple myeloma-educated dendritic cells

2017

Dendritic cells (DCs) have a key role in regulating tumor immunity, tumor cell growth and drug resistance. We hypothesized that multiple myeloma (MM) cells might recruit and reprogram DCs to a tumor-permissive phenotype by changes within their microRNA (miRNA) network. By analyzing six different miRNA-profiling data sets, miR-29b was identified as the only miRNA upregulated in normal mature DCs and significantly downregulated in tumor-associated DCs. This finding was validated in primary DCs co-cultured in vitro with MM cell lines and in primary bone marrow DCs from MM patients. In DCs co-cultured with MM cells, enforced expression of miR-29b counteracted pro-inflammatory pathways, includin…