1,167 research outputs found
UJM at INEX 2009 Ad Hoc track
7 pagesInternational audienceThis paper1 presents our participation to the INEX 2009 Ad- Hoc track. We have experimented the tuning of various parameters using a ”training” collection (i.e. INEX 2008) quite different than the ”testing” collection used for 2009 INEX Ad-Hoc track. Several parameters have been studied for article retrieval as well as for element retrieval, especially the two main BM25 weighting function parameters: b and k1
Object-based Integrated Landscape Change Analysis: synergy of multi-temporal LiDAR and very high resolution orthophotos
LiDAR and Orthophoto Synergy to optimize Object-Based Landscape Change:Analysis of an Active Landslide
Active landslides have three major effects on landscapes: (1) land cover change, (2) topographical change, and (3) above ground biomass change. Data derived from multi-temporal Light Detection and Ranging technology (LiDAR) are used in combination with multi-temporal orthophotos to quantify these changes between 2006 and 2012, caused by an active deep-seated landslide near the village of Doren in Austria. Land-cover is classified by applying membership-based classification and contextual improvements based on the synergy of orthophotos and LiDAR-based elevation data. Topographical change is calculated by differencing of LiDAR derived digital terrain models. The above ground biomass is quantified by applying a local-maximum algorithm for tree top detection, in combination with allometric equations. The land cover classification accuracies were improved from 65% (using only LiDAR) and 76% (using only orthophotos) to 90% (using data synergy) for 2006. A similar increase from respectively 64% and 75% to 91% was established for 2012. The increased accuracies demonstrate the effectiveness of using data synergy of LiDAR and orthophotos using object-based image analysis to quantify landscape changes, caused by an active landslide. The method has great potential to be transferred to larger areas for use in landscape change analyses
Population density equations for stochastic processes with memory kernels
We present a method for solving population density equations (PDEs)–-a mean-field technique describing homogeneous populations of uncoupled neurons—where the populations can be subject to non-Markov noise for arbitrary distributions of jump sizes. The method combines recent developments in two different disciplines that traditionally have had limited interaction: computational neuroscience and the theory of random networks. The method uses a geometric binning scheme, based on the method of characteristics, to capture the deterministic neurodynamics of the population, separating the deterministic and stochastic process cleanly. We can independently vary the choice of the deterministic model and the model for the stochastic process, leading to a highly modular numerical solution strategy. We demonstrate this by replacing the master equation implicit in many formulations of the PDE formalism by a generalization called the generalized Montroll-Weiss equation—a recent result from random network theory—describing a random walker subject to transitions realized by a non-Markovian process. We demonstrate the method for leaky- and quadratic-integrate and fire neurons subject to spike trains with Poisson and gamma-distributed interspike intervals. We are able to model jump responses for both models accurately to both excitatory and inhibitory input under the assumption that all inputs are generated by one renewal process
A dynamical neural simulation mapping feature-based attention to location with non-linear cortical circuits
The treatment of primary tumors of the femur with chemotherapy (if indicated), resection and reconstruction with an endoprosthesis
The treatment protocol of 15 patients with a primary tumor of the femur, including osteosarcoma, malignant fibrous histiocytoma and chondrosar-coma is presented. All patients had been selected for resection and reconstruction with an endoprosthesis. An endoprothesis was implanted in 12 patients. \ud
The results of this type of treatment appear to be satisfactory. In eight osteosarcoma cases resection and reconstruction with an endoprosthesis combined with preoperative and postoperative chemotherapy, according to Rosen, were performed. Follow-up in all 15 patients, varying from 1.4 to 6.0 years, showed no evidence of disease in 12 patients. Three patients had died. Function of the involved leg was satisfactory in most cases. \ud
The advantage and disadvantages of the use of an endoprosthesis are discussed as well as complications in this series of patients
Unintentional ingestion of a high dose of acenocoumarol in a young child
Acute intoxication with a vitamin K antagonist may cause serious coagulopathy. We report the accidental ingestion of a high dose of acenocoumarol in a young child. Two intravenous administrations of 5mg of vitamin K, in combination with fast and repeated administration of activated charcoal and sodium sulfate, were sufficient to prevent coagulopathy and related symptoms, despite a confirmed elevated blood acenocoumarol concentration (260 mu g/L)
The possible role of matrix metalloproteinase (MMP)-2 and MMP-9 in cancer, e.g. acute leukemia
In the past decades, a lot of effort has been put in identifying the role of matrix metalloproteinases (MMPs) in cancer. The main role of MMPs in angiogenesis, tumor growth and metastasis is degradation of extracellular matrix (ECM) and release and/or activation of growth factors through their degradative activity. The degradative activity finally results in cancer progression. MMP-inhibitors (MMPIs) have already been designed and tested, based on the degradative role of MMPs in cancer progression. First clinical trials with MMPIs have been performed with disappointing results, showing that in order to use MMP-inhibition the mechanisms underlying MMP-expression in cancer have to be further elucidated. This paper reviews the mechanisms of MMPs on molecular and cellular level and discusses the role for MMPs and MMP-inhibition in cancer with special focus on acute leukemia
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