A modified extended kalman filter as a parameter estimator for linear discrete-time systems

This thesis presents the derivation and implementation of a modified Extended Kalman Filter used for Joint state and parameter estimation of linear discrete-time systems operating in a, stochastic Gaussian environment. A novel derivation for the discrete-time Extended Kalman Filter is also presented. In order to eliminate the main deficiencies of the Extended Kalman Filter, which are divergence and biasedness of its estimates, the filter algorithm has been modified. The primary modifications are due to Ljung, who stated global convergence properties for the modified Extended Kalman Filter, when used as a parameter estimator for linear systems. Implementation of this filter is further complicated by the need to initialize the parameter estimate error covariance inappropriately small, to assure filter stability. In effect, due to this inadequate initialization process the parameter estimates fail to converge. Several heuristic methods have been developed to remove the effects of the inadequate initial parameter estimate covariance matrix on the filter\u27s convergence properties. Performance of the improved modified Extended Kalman Filter is compared with the Recursive Extended Least Squares parameter estimation scheme

Genetic variation in growth and yield components of juvenile balsam poplar (Populus balsamifera L.) growing in northwestern Ontario / by Frank Schnekenburger

A nursery and greenhouse study of balsam poplar (Populus balsamifera L.) were carried out in Thunder Bay, Ontario, to study the extent and nature of variation in growth and its relation to the following yield components: phenology, assimilation rate, leaf morphology, and assimilate distribution. The studies involved clones of four sources of balsam poplar selected along an approximate latitudinal gradient: N. Wisconsin (45-46®N), Thunder Bay (48-49®N), Pickle Lake (51-52®N), and Severn River (53-54®N). As part of the greenhouse study, the effects of a reduction in the daily period of photosynthate production were studied. For this purpose, plants were grown under either a normal or reduced photosynthetic period of approximately 16 or 8 hours per day, respectively. The reduced photosynthetic period was achieved W covering plants with opaque shade cloth from 4:00 p.m. of one day until 8:00 a.m. of the next day. Low-level incandescent lighting provided cua 18-hour photoperiod that prevented height growth cessation under both photos3mthetic periods. The nursery study demonstrated significant variation among clones of the Thunder Bay and Pickle Lake sources, in terms of date of bud break and growth cessation, initial plant height, and total shoot elongation. Date of growth cessation differed significantly between sources, occurring eight days earlier for the Pickle Lake source than for the Thunder Bay source; source differences in date of bud breads: were not significant. Total shoot elongation was moderately correlated with date of growth cessation, but not with date of bud break. The greenhouse study entailed assessment of clones from all four sources. Clonal variation was significant in terms of leaf, stem, and root dry weight; leaf area and number; shoot length; and root number. Relative growth rate (RGR) differed significantly among sources; clonal variation in RGR and in relative leaf weight growth rate (RLwGR) and relative leaf area growth rate (RLaGR) was significant for some sources, but not others. Differences in RGR were closely linked to differences in unit leaf rate, but not to leaf growth characteristics. Plants under the reduced photosynthetic period produced less dry weight and leaf area, fewer leaves, and less shoot growth than those lander the normal photosynthetic period. Relative growth rate, unit leaf rate, and the allometric constant relating the relative rate of shoot growth to that of root growth were also lower under the reduced photosynthetic period. Leaf area ratio was greater under the reduced photosynthetic period, largely due to greater specific leaf area. Marked changes in clonal rankings based on relative growth rates suggest that differences exist among the clones studied in their response to the reduced photosynthetic period. In general, the reduced photosynthetic period affected the southern sources to a lesser degree than the northern sources

(E)-2-Bromo­benzaldehyde oxime

The configuration of the C=N double bond of the title compound, C7H6BrNO, is E; the non-H atoms are approximately coplanar (r.m.s. deviation = 0.038 Å). In the crystal, pairs of mol­ecules are linked by a pair of O—H⋯N hydrogen bonds about a center of inversion, generating hydrogen-bonded dimers

E-Learning an der Universität Rostock: Eine explorative, quantitative Online-Trenderhebung zum tatsächlichen Einsatz von Stud.IP

In der vorliegenden Dissertation wurde der Einsatz des Lehr-/Lernmanagementsystems Stud.IP an der Universität Rostock untersucht. Die einleitenden Kapitel widmen sich einer Reflektion des E-Learnings und geben eine Übersicht zum aktuellen Stand der Online-Forschung. Der Schwerpunkt der Arbeit liegt auf der Durchführung und Reflektion der dreistufigen Online-Trenderhebung. Die Ergebnisse der Befragung (126 Lehrende und 1164 Studierende) zeigen eine zurückhaltende Nutzung der vielen Funktionalitäten der Plattform. In einem abschließenden Kapitel werden neue Forschungsperspektiven aufgezeigt

Discovery of Sulforaphane as an Inducer of Ferroptosis in U-937 Leukemia Cells: Expanding Its Anticancer Potential

In recent years, natural compounds have emerged as inducers of non-canonical cell death. The isothiocyanate sulforaphane (SFN) is a well-known natural anticancer compound with remarkable pro-apoptotic activity. Its ability to promote non-apoptotic cell-death mechanisms remains poorly investigated. This work aimed to explore the capacity of SFN to induce non-apoptotic cell death modalities. SFN was tested on different acute myeloid leukemia cell lines. The mechanism of cell death was investigated using a multi-parametric approach including fluorescence microscopy, western blotting, and flow cytometry. SFN triggered different cell-death modalities in a dose-dependent manner. At 25 μM, SFN induced caspase-dependent apoptosis and at 50 μM ferroptosis was induced through depletion of glutathione (GSH), decreased GSH peroxidase 4 protein expression, and lipid peroxidation. In contrast, necroptosis was not involved in SFN-induced cell death, as demonstrated by the non-significant increase in phosphorylation of receptor-interacting protein kinase 3 and phosphorylation of the necroptotic effector mixed lineage kinase domain-like pseudokinase. Taken together, our results suggest that the antileukemic activity of SFN can be mediated via both ferroptotic and apoptotic cell death modalities

Metamodel-Aware Textual Concrete Syntax Specification

Metamodeling is raising more and more interest in the field of language engineering. While this approach is now well understood for the definition of abstract syntaxes, the formal definition of concrete syntaxes is still a challenge. Concrete syntaxes are traditionally expressed with rules, conforming to EBNF-like grammars, which can be processed by compiler compilers to generate parsers. Unfortunately, these generated parsers produce concrete syntax trees, leaving a gap with the abstract syntax defined by metamodels. This gap is usually filled by time consuming ad-hoc hand-coding. In this paper we propose a new kind of specification for concrete syntaxes that takes advantage of metamodels to generate tools (such as parsers or text generators) which directly manipulate abstract syntax trees. The principle is to map abstract syntaxes to concrete syntaxes via EBNF-like rules that explain how to render an abstract concept into a given concrete syntax, and how to trigger other rules to handle the properties of the concepts. The major difference with EBNF is that rules may have sub-rules, which can be automatically triggered based on the inheritance hierarchy of the abstract syntax concepts

Novel inhibitors of human histone deacetylases: Design, synthesis and bioactivity of 3-alkenoylcoumarines

International audienceHistone deacetylases (HDACs) are well-established, promising targets for anticancer therapy due to their critical role in cancer development. Accordingly, an increasing number of HDAC inhibitors displaying cytotoxic effects against cancer cells have been reported. Among them, a large panel of chemical structures was described including coumarin-containing molecules. In this study, we described synthesis and biological activity of new coumarin-based derivatives as HDAC inhibitors. Among eight derivatives, three compounds showed HDAC inhibitory activities and antitumor activities against leukemia cell lines without affecting the viability of peripheral blood mononuclear cells from healthy donors

Cytotoxicity screening of 23 engineered nanomaterials using a test matrix of ten cell lines and three different assays

<p>Abstract</p> <p>Background</p> <p>Engineered nanomaterials display unique properties that may have impact on human health, and thus require a reliable evaluation of their potential toxicity. Here, we performed a standardized <it>in vitro </it>screening of 23 engineered nanomaterials. We thoroughly characterized the physicochemical properties of the nanomaterials and adapted three classical <it>in vitro </it>toxicity assays to eliminate nanomaterial interference. Nanomaterial toxicity was assessed in ten representative cell lines.</p> <p>Results</p> <p>Six nanomaterials induced oxidative cell stress while only a single nanomaterial reduced cellular metabolic activity and none of the particles affected cell viability. Results from heterogeneous and chemically identical particles suggested that surface chemistry, surface coating and chemical composition are likely determinants of nanomaterial toxicity. Individual cell lines differed significantly in their response, dependent on the particle type and the toxicity endpoint measured.</p> <p>Conclusion</p> <p><it>In vitro </it>toxicity of the analyzed engineered nanomaterials cannot be attributed to a defined physicochemical property. Therefore, the accurate identification of nanomaterial cytotoxicity requires a matrix based on a set of sensitive cell lines and <it>in vitro </it>assays measuring different cytotoxicity endpoints.</p

Distinct role of subunits of the Arabidopsis RNA polymerase II elongation factor PAF1C in transcriptional reprogramming

Transcript elongation by RNA polymerase II (RNAPII) is dynamic and highly regulated, thereby contributing to the implementation of gene expression programs during plant development or in response to environmental cues. The heterohexameric polymerase-associated factor 1 complex (PAF1C) stabilizes the RNAPII elongation complex promoting efficient transcript synthesis. In addition, PAF1C links transcriptional elongation with various post-translational histone modifications at transcribed loci. We have exposed Arabidopsis mutants deficient in the PAF1C subunits ELF7 or CDC73 to elevated NaCl concentrations to provoke a transcriptional response. The growth of elf7 plants was reduced relative to that of wildtype under these challenging conditions, whereas cdc73 plants exhibited rather enhanced tolerance. Profiling of the transcriptional changes upon NaCl exposure revealed that cdc73 responded similar to wildtype. Relative to wildtype and cdc73, the transcriptional response of elf7 plants was severely reduced in accord with their greater susceptibility to NaCl. The data also imply that CDC73 is more relevant for the transcription of longer genes. Despite the fact that both ELF7 and CDC73 are part of PAF1C the strikingly different transcriptional response of the mutants upon NaCl exposure suggests that the subunits have (partially) specific functions