An adaptive learning algorithm for a wavelet neural network

Abstract: An optimal online learning algorithm of a wavelet neural network is proposed. The algorithm provides not only the tuning of synaptic weights in real time, but also the tuning of dilation and translation factors of daughter wavelets. The algorithm has both tracking and smoothing properties, so the wavelet networks trained with this algorithm can be efficiently used for prediction, filtering, compression and classification of various non-stationary noisy signals.     

Interaction of Alpha Synuclein and Microtubule Organization Is Linked to Impaired Neuritic Integrity in Parkinson’s Patient-Derived Neuronal Cells

Parkinson’s disease (PD) is neuropathologically characterized by the loss of dopaminergic neurons and the deposition of aggregated alpha synuclein (aSyn). Mounting evidence suggests that neuritic degeneration precedes neuronal loss in PD. A possible underlying mechanism could be the interference of aSyn with microtubule organization in the neuritic development, as implied by several studies using cell-free model systems. In this study, we investigate the impact of aSyn on microtubule organization in aSyn overexpressing H4 neuroglioma cells and midbrain dopaminergic neuronal cells (mDANs) generated from PD patient-derived human induced pluripotent stem cells (hiPSCs) carrying an aSyn gene duplication (SNCA^Dupl). An unbiased mass spectrometric analysis reveals a preferential binding of aggregated aSyn conformers to a number of microtubule elements. We confirm the interaction of aSyn with beta tubulin III in H4 and hiPSC-derived mDAN cell model systems, and demonstrate a remarkable redistribution of tubulin isoforms from the soluble to insoluble fraction, accompanied by a significantly increased insoluble aSyn level. Concordantly, SNCA^Dupl mDANs show impaired neuritic phenotypes characterized by perturbations in neurite initiation and outgrowth. In summary, our findings suggest a mechanistic pathway, through which aSyn aggregation interferes with microtubule organization and induces neurite impairments.     

COX-2 Inhibition and Inhibition of Cytosolic Phospholipase A2 Increase CD36 Expression and Foam Cell Formation in THP-1 Cells

Cardiovascular safety of cyclooxygenase (COX)-2-selective inhibitors and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) is of worldwide concern. COX-2 inhibitors and NSAIDs act by inhibiting arachidonic acid metabolism to prostaglandins. They confer a cardiovascular hazard manifested as an elevated risk of myocardial infarction. Mechanisms underlying these cardiovascular effects are uncertain. Here we determine whether interference with cytosolic phospholipase A2 (cPLA-2) or COX-2 through pharmacologic blockade or silencing RNA impacts expression of scavenger receptor CD36 and scavenger receptor A, both involved in cholesterol uptake in monocytes and macrophages. THP-1 human monocytes and human peripheral blood mononuclear cells were exposed to celecoxib, a COX-2 selective inhibitor currently in clinical use, and to arachidonyl trifluoromethyl ketone (AACOCF3), an arachidonic acid analog that selectively inhibits cPLA-2. Celecoxib and AACOCF3 each upregulated expression of CD36, but not scavenger receptor A, as determined by quantitative PCR and immunoblotting. Silencing of cPLA-2 or COX-2 had comparable effects to pharmacologic treatments. Oil red O staining revealed a profound increase in foam cell transformation of THP-1 macrophages exposed to either celecoxib or AACOCF3 (both 25 μM), supporting a role for the COX pathway in maintaining macrophage cholesterol homeostasis. Demonstration of disrupted cholesterol balance by AACOCF3 and celecoxib provides further evidence of the possible mechanism by which COX inhibition may promote lipid overload leading to atheromatous lesion formation and increased cardiovascular events.     

Model to predict the viscoelastic response of a semi-crystalline polymer under complex cyclic mechanical loading and unloading conditions

To predict the behaviour of a semi-crystalline polymer under complex cyclic mechanical loading and unloading conditions, a non-linear rheological model, previously developed to predict the viscoelastic behaviour under uniaxial monotonous loading and unloading conditions, was used as a starting point and generalised in three-dimensions (3D). The initial model was created on the assumption that the amorphous phase of the semi-crystalline polymer follows the particular reversible mechanism of viscoelastic deformations. This assumption allowed to model the mechanical behaviour of the semi-crystalline polymer under loading and unloading conditions without changing the parameters at the point when the loading was reversed. The parameters of the 3D generalised model under tension, torsion (shearing) and compression conditions were identified from the fitting of the respective uniaxial mechanical tests. It was demonstrated that the 3D model agreed with the experimental data obtained under complex proportional and non-proportional mechanical loading. It was also demonstrated that the model is able to reproduce more then one loop of the cyclic loading.     

A method for identifying Web applications

Web applications are ubiquitous in today’s businesses. The security of these applications is of utmost importance since security breaches might negatively impact good reputation, and even result in bankruptcy. There are different methods of assessing security of Web applications, mainly based on some automated method of scanning. One type of scan method feeds random data to the application and monitors its behavior. The other type uses a database with predefined vulnerabilities that are checked one by one until either a vulnerability is found, or it can be claimed that the application does not have any known vulnerabilities. The important step in latter type of scan process is the identification of the application since in this case we are narrowing number of checks and, as a consequence, the scan process is faster. This paper describes a method for Web application identification based on a black box principle. Our method is based on the invariance of certain characteristics of Web applications. We experimentally tested and confirmed the usefulness of this approach.     

The Diverse Transformer (Trf) Protein Family in the Sea Urchin Paracentrotus lividus Acts through a Collaboration between Cellular and Humoral Immune Effector Arms

Sea urchins are long-living marine invertebrates with a complex innate immune system, which includes expanded families of immune receptors. A central immune gene family in sea urchins encodes the Transformer (Trf) proteins. The Trf family has been studied mainly in the purple sea urchin Strongylocentrotus purpuratus. Here, we explore this protein family in the Mediterranean Sea urchin Paracentrotus lividus. The PlTrf genes and predicted proteins are highly diverse and show a typical Trf size range and structure. Coelomocytes and cell-free coelomic fluid from P. lividus contain different PlTrf protein repertoires with a shared subset, that bind specifically to E. coli. Using FACS, we identified five different P. lividus coelomocyte sub-populations with cell surface PlTrf protein expression. The relative abundance of the PlTrf-positive cells increases sharply following immune challenge with E. coli, but not following challenge with LPS or the sea urchin pathogen, Vibrio penaeicida. Phagocytosis of E. coli by P. lividus phagocytes is mediated through the cell-free coelomic fluid and is inhibited by blocking PlTrf activity with anti-SpTrf antibodies. Together, our results suggest a collaboration between cellular and humoral PlTrf-mediated effector arms in the P. lividus specific immune response to pathogens.