Learning Local Feature Aggregation Functions with Backpropagation

This paper introduces a family of local feature aggregation functions and a novel method to estimate their parameters, such that they generate optimal representations for classification (or any task that can be expressed as a cost function minimization problem). To achieve that, we compose the local feature aggregation function with the classifier cost function and we backpropagate the gradient of this cost function in order to update the local feature aggregation function parameters. Experiments on synthetic datasets indicate that our method discovers parameters that model the class-relevant information in addition to the local feature space. Further experiments on a variety of motion and visual descriptors, both on image and video datasets, show that our method outperforms other state-of-the-art local feature aggregation functions, such as Bag of Words, Fisher Vectors and VLAD, by a large margin.Comment: In Proceedings of the 25th European Signal Processing Conference (EUSIPCO 2017

Protective activity of aromatic amines and imines against oxidative nerve cell death

Oxidative stress is a widespread phenomenon in the pathology of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Neuronal cell death due to oxidative stress may causally contribute to the pathogeneses of these diseases. Therefore, neuroprotective antioxidants are considered to be a promising approach to slow down disease progression. We have investigated different aromatic amine and imine compounds for neuroprotective antioxidant functions in cell culture, and found that these compounds possess excellent cytoprotective potential in diverse paradigms of oxidative neuronal cell death, including clonal cell lines, primary cerebellar neurons, and organotypic hippocampal slice cultures. Aromatic amines and imines are effective against oxidative glutamate toxicity, glutathione depletion, and hydrogen peroxide toxicity. Their mode of action as direct antioxidants; was experimentally confirmed by electron spin resonance spectroscopy, cell-free brain lipid peroxidation assays, and intracellular peroxide measurements. With half-maximal effective concentrations of 20-75 nm in different neuroprotection experiments, the aromatic imines phenothiazine, phenoxazine, and iminostilbene proved to be about two orders of magnitude more effective than common phenolic antioxidants. This remarkable efficacy could be directly correlated to calculated properties of the compounds by means of a novel, quantitative structure-activity relationship model. We conclude that bridged bisarylimines with a single free NH-bond, such as iminostilbene, are superior neuroprotective antioxidants, and may be promising lead structures for rational drug development

Histone complement of a rapidly evolving chordate Oikopleura dioica: Developmental and sex-specific deployment of novel and universal histone variants and their posttranslational modifications

The packaging of DNA into nucleosomes is a fundamentally conserved property of the eukaryotic nucleus which is evident in the conservation of histone sequences. Nevertheless, it is now clear that histone sequence variants have diversified in many species to assume crucial roles in the regulation of gene expression, DNA repair, chromosome segregation and other processes. While considerable data exist on coding sequences of histones and some selected histone variants in a wide variety of organisms, the information available on total histone gene complements is much more limited. Oikopleura dioica (Od) is a dioecious marine urochordate that occupies a key phylogenetic position near the invertebrate-vertebrate transition with the smallest genome ever found in a chordate (70 Mb). Its short life cycle is characterized by a developmental switch between mitotic and endocycling cells, making O. dioica an attractive model to study the spatial and temporal use of histone variants and posttranslational histone modifications (PTMs) throughout development and in different cell cycle types. We have characterized the complete histone gene complement and the developmental expression of histone genes present in the first assembly of the O. dioica draft genome and identified the major Od PTMs by massspectrometric analysis. Furthermore, we analyzed the dynamics and distribution of phosphorylated H3 variants during mitosis and meiosis of O. dioica and the deposition of the centromeric variant OdCenH3 in mitotic and endocycling cells with respect to centromeric PTMs. The Od histone gene complement displays several features not known from other chordates, including male-specific variants in all of the core histone families, N-terminal H2A.Z splice variants, and a diverse array of H2A variants but absence of the near universal variant H2AX. The results here suggest significant plasticity in histone gene organization, the variation within histone families and the chromosomal distribution of mitotic PTMs within the chordate lineage. This further supports the view that histone gene complements may also evolve adaptively to the specific life history traits, cell cycle regulation and genome architecture of organisms

Interlacing Self-Localization, Moving Object Tracking and Mapping for 3D Range Sensors

This work presents a solution for autonomous vehicles to detect arbitrary moving traffic participants and to precisely determine the motion of the vehicle. The solution is based on three-dimensional images captured with modern range sensors like e.g. high-resolution laser scanners. As result, objects are tracked and a detailed 3D model is built for each object and for the static environment. The performance is demonstrated in challenging urban environments that contain many different objects

Milieu-adopted in vitro and in vivo differentiation of mesenchymal tissues derived from different adult human CD34-negative progenitor cell clones

Adult mesenchymal stem cells with multilineage differentiation potentially exist in the bone marrow, but have also been isolated from the peripheral blood. The differentiation of stem cells after leaving their niches depends predominately on the local milieu and its new microenvironment, and is facilitated by soluble factors but also by the close cell-cell interaction in a three-dimensional tissue or organ system. We have isolated CD34-negative, mesenchymal stem cell lines from human bone marrow and peripheral blood and generated monoclonal cell populations after immortalization with the SV40 large T-antigen. The cultivation of those adult stem cell clones in an especially designed in vitro environment, including self-constructed glass capillaries with defined growth conditions, leads to the spontaneous establishment of pleomorphic three-dimensional cell aggregates ( spheroids) from the monoclonal cell population, which consist of cells with an osteoblast phenotype and areas of mineralization along with well-vascularized tissue areas. Modifications of the culture conditions favored areas of bone-like calcifications. After the transplantation of the at least partly mineralized human spheroids into different murine soft tissue sites but also a dorsal skinfold chamber, no further bone formation could be observed, but angiogenesis and neovessel formation prevailed instead, enabling the transplanted cells and cell aggregates to survive. This study provides evidence that even monoclonal adult human CD34-negative stem cells from the bone marrow as well as peripheral blood can potentially differentiate into different mesenchymal tissues depending on the local milieu and responding to the needs within the microenvironment. Copyright (C) 2005 S. Karger AG, Basel

Effective second-line treatment with cetuximab and bevacizumab in a patient with hepatic metastases of colorectal cancer and hyperbilirubinemia

Background: Irinotecan-based second-line chemotherapy of metastatic colorectal cancer (CRC) is effective, it might, however, be contraindicated in cases of severe liver dysfunction due to advanced liver metastases. Case Report: A 57-year-old woman with diffuse CRC liver metastases showed progressive disease on first-line treatment with capecitabine and oxaliplatin (XELOX). Chronic cholestasis and hyperbilirubinemia caused by advanced liver involvement prohibited second-line treatment with irinotecan-based chemotherapy. We initiated combined antibody treatment with cetuximab and bevacizumab. Results: Clinical performance status as well as laboratory parameters improved rapidly. Staging investigations after 8 weeks revealed a partial remission. Since bilirubin levels had returned to the upper limit of normal, therapy could be changed to standard irinotecan, 5-fluorouracil, folinic acid, and bevacizumab. Conclusion: Combined treatment with cetuximab and bevacizumab may be considered as an effective treatment option in patients who cannot be treated with standard chemotherapy regimens due to impaired liver metabolism of cytotoxic substances

Design und Simulation von Nanoantennen

Diese Dissertation beschäftigt sich mit dem Design und der Simulation von Nanoantennen

Mesenchymal Differentiation and Organ Distribution of Established Human Stromal Cell Lines in NOD/SCID Mice

Two human stromal cell lines were established previously from bone marrow-derived primary long-term cultures by immortalization using the SV40 large T antigen and cellular cloning. After irradiation, the fibroblast-like cell lines L87/4 and L88/5 support hematopoietic differentiation of allogeneic cord blood cells in vitro. The stromal cells do not express CD34 and CD50, but some adhesion molecules and integrins, such as CD44, CD54 and CD58. Their expression profiles on RNA and protein levels are suggestive of their osteogenic potency. The quality and quantity of osteocalcin and osteopontin protein expression depended on the culture conditions. Expression of the osteogenic markers increased over time in culture, especially in cells growing in clusters. The stromal cells also expressed collagens I and V, but did not show any expression of collagens II and III. The potentially osteoblastic stromal cells were transplanted into NOD/SCID recipient mice by intravenous injection and were found in various mesenchymal organs up to 10 weeks after transplantation. Osteocalcin-positive human stromal cells could be detected in the bone marrow, thymus, liver, brain and gut of the recipient animals. In summary, there is evidence that human bone-marrow-derived stromal cells have to be considered mesenchymal progenitors, persistently expressing osteogenic markers in vitro and in vivo. Copyright (C) 2001 S, Karger AG, Basel