Asymptotic Level Density of the Elastic Net Self-Organizing Feature Map

Whileas the Kohonen Self Organizing Map shows an asymptotic level density following a power law with a magnification exponent 2/3, it would be desired to have an exponent 1 in order to provide optimal mapping in the sense of information theory. In this paper, we study analytically and numerically the magnification behaviour of the Elastic Net algorithm as a model for self-organizing feature maps. In contrast to the Kohonen map the Elastic Net shows no power law, but for onedimensional maps nevertheless the density follows an universal magnification law, i.e. depends on the local stimulus density only and is independent on position and decouples from the stimulus density at other positions.Comment: 8 pages, 10 figures. Link to publisher under http://link.springer.de/link/service/series/0558/bibs/2415/24150939.ht

Dimensional structural constants from chiral and conformal bosonization of QCD

We derive the dimensional non-perturbative part of the QCD effective action for scalar and pseudoscalar meson fields by means of chiral and conformal bosonization. The related structural coupling constants L_5 and L_8 of the chiral lagrangian are estimated using general relations which are valid in a variety of chiral bosonization models without explicit reference to model parameters. The asymptotics for large scalar fields in QCD is elaborated, and model-independent constraints on dimensional coupling constants of the effective meson lagrangian are evaluated. We determine also the interaction between scalar quarkonium and the gluon density and obtain the scalar glueball-quarkonium potential.Comment: 21 pages, LaTe

3D-4D Interlinkage Of qqq Wave Functions Under 3D Support For Pairwise Bethe-Salpeter Kernels

Using the method of Green's functions within a Bethe-Salpeter framework characterized by a pairwise qq interaction with a Lorentz-covariant 3D support to its kernel, the 4D BS wave function for a system of 3 identical relativistic spinless quarks is reconstructed from the corresponding 3D form which satisfies a fully connected 3D BSE. This result is a 3-body generalization of a similar 2-body result found earlier under identical conditions of a 3D support to the corresponding qq-bar BS kernel under Covariant Instaneity (CIA for short). (The generalization from spinless to fermion quarks is straightforward). To set the CIA with 3D BS kernel support ansatz in the context of contemporary approaches to the qqq baryon problem, a model scalar 4D qqq BSE with pairwise contact interactions to simulate the NJL-Faddeev equations is worked out fully, and a comparison of both vertex functions shows that the CIA vertex reduces exactly to the NJL form in the limit of zero spatial range. This consistency check on the CIA vertex function is part of a fuller accounting for its mathematical structure whose physical motivation is traceable to the role of `spectroscopy' as an integral part of the dynamics.Comment: 20 pages, Latex, submitted via the account of K.-C. Yan

GSTM1 Modulates Expression of Endothelial Adhesion Molecules in Uremic Milieu

Deletion polymorphism of glutathione S-transferase M1 (GSTM1), a phase II detoxification and antioxidant enzyme, increases susceptibility to end-stage renal disease (ESRD) as well as the development of cardiovascular diseases (CVD) among ESRD patients and leads to their shorter cardiovascular survival. The mechanisms by which GSTM1 downregulation contributes to oxidative stress and inflammation in endothelial cells in uremic conditions have not been investigated so far. Therefore, the aim of the present study was to elucidate the effects of GSTM1 knockdown on oxidative stress and expression of a panel of inflammatory markers in human umbilical vein endothelial cells (HUVECs) exposed to uremic serum. Additionally, we aimed to discern whether GSTM1-null genotype is associated with serum levels of adhesion molecules in ESRD patients. HUVECs treated with uremic serum exhibited impaired redox balance characterized by enhanced lipid peroxidation and decreased antioxidant enzyme activities, independently of the GSTM1 knockdown. In response to uremic injury, HUVECs exhibited alteration in the expression of a series of inflammatory cytokines including retinol-binding protein 4 (RBP4), regulated on activation, normal T cell expressed and secreted (RANTES), C-reactive protein (CRP), angiogenin, dickkopf-1 (Dkk-1), and platelet factor 4 (PF4). GSTM1 knockdown in HUVECs showed upregulation of monocyte chemoattractant protein-1 (MCP-1), a cytokine involved in the regulation of monocyte migration and adhesion. These cells also have shown upregulated intracellular and vascular cell adhesion molecules (ICAM-1 and VCAM-1). In accordance with these findings, the levels of serum ICAM-1 and VCAM-1 (sICAM-1 and sVCAM-1) were increased in ESRD patients lacking GSTM1, in comparison with patients with the GSTM1-active genotype. Based on these results, it may be concluded that incubation of endothelial cells in uremic serum induces redox imbalance accompanied with altered expression of a series of cytokines involved in arteriosclerosis and atherosclerosis. The association of GSTM1 downregulation with the altered expression of adhesion molecules might be at least partly responsible for the increased susceptibility of ESRD patients to CVD

Monopoles and Knots in Skyrme Theory

We show that the Skyrme theory actually is a theory of monopoles which allows a new type of solitons, the topological knots made of monopole-anti-monopole pair,which is different from the well-known skyrmions. Furthermore, we derive a generalized Skyrme action from the Yang-Mills action of QCD, which we propose to be an effective action of QCD in the infra-red limit. We discuss the physical implications of our results.Comment: 4 pages. Phys. Rev. Lett. in pres

UTICAJ ĐUBRENJA AZOTOM I PODSEJAVANJA NA PRINOS I KVALITET TRAVNJAKA CYNOSURETUM CRISTATI U PLANINSKOM PODRUČJU SRBIJE

The trial was carried out during two years (2003 and 2004) on Cynosuretum cristati-type meadow in the hillymountainous region of Serbia (altitude 1158 m). The investigation included five nitrogen fertilizer rates (0, 40, 80, 120 and 160 kg ha-1 yr-1) and undersowing with red clover and birdsfoot trefoil. Increase in nitrogen fertilization level resulted in corresponding increases in the quantity and quality of grass, while legumes and other herbages decreased. Maximum two-year average dry matter yield of 4.44 t ha-1 was achieved with the highest N rate (160 kg ha-1). The increase was 2.03 t ha-1 or 85.0% compared with the control. Increased N rates increasing the contents of protein, ash, fat, Cu, Co, and NO3, and reduced the contents of cellulose, K, P, Ca, Mg, S, Zn, and B. Dry matter yield in the undersowing treatment was low, only slightly over that of the control in both study years. Furthermore, undersowing failed to affect the chemical and mineral composition of dry matter.Istraživanje je obavljeno na travnjaku tipa Cynosuretum cristati u planinskom području Srbije, na nadmorskoj visini oko 1158 m, tokom dve godine (2002 - 2003. g.). U istraživanju je proučavan uticaj azotnog đubriva i podsejavanja sa crvenom detelinom i žutim zvezdanom na prinos suve materije (SM) u sledećim varijantama đubriva (0, 40, 80, 120 i 160 kg/ha). Sa povećanjem količine azotnog đubriva povećao se udeo i kvalitet trava a udeo leptirnjača i bioljaka iz ostalih familija se smanjivao. Maksimalan dvogodišnji prosečan prinos SM je iznosio 4.44 t ha-1 a postignut je sa najvećom količinom azotnog đubriva (160 kg ha-1). Povećanje je iznosilo 2.03 t ha-1 ili 85.0% u odnosu na kontrolu. Sa povećanjem količine primenjenog azotnog đubriva povećavao se sadržaj proteina, pepela, masti Cu, Co i NO3, a smanjivala količina celuloze, K, P, Ca, Mg, S, Zn i B. Prinos SM sa primenom podsejavanja je bio nizak, nešto viši u odnosu na kontrolu u obe godine istraživanja. Primena podsejavanja nije imala uticaja na promenu hemijskog i mineralnog sastava u SM prinosa

Self-assembly in solution of a reversible comb-shaped supramolecular polymer

We report a single step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a combshaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration or the temperature. Moreover, we have proved that the bulkiness of the side-chains have a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the density of arms can be reduced, by simply mixing with a low molar mass bis-urea