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

Investigations of the pi N total cross sections at high energies using new FESR: log nu or (log nu)^2

We propose to use rich informations on pi p total cross sections below N= 10 GeV in addition to high-energy data in order to discriminate whether these cross sections increase like log nu or (log nu)^2 at high energies, since it is difficult to discriminate between asymptotic log nu and (log nu)^2 fits from high-energy data alone. A finite-energy sum rule (FESR) which is derived in the spirit of the P' sum rule as well as the n=1 moment FESR have been required to constrain the high-energy parameters. We then searched for the best fit of pi p total cross sections above 70 GeV in terms of high-energy parameters constrained by these two FESR. We can show from this analysis that the (log nu)^2 behaviours is preferred to the log nu behaviours.Comment: to be published in Phys. Rev. D 5 pages, 2 eps figure

Experimental evidence of a fractal dissipative regime in high-T_c superconductors

We report on our experimental evidence of a substantial geometrical ingredient characterizing the problem of incipient dissipation in high-T_c superconductors(HTS): high-resolution studies of differential resistance-current characteristics in absence of magnetic field enabled us to identify and quantify the fractal dissipative regime inside which the actual current-carrying medium is an object of fractal geometry. The discovery of a fractal regime proves the reality and consistency of critical-phenomena scenario as a model for dissipation in inhomogeneous and disordered HTS, gives the experimentally-based value of the relevant finite-size scaling exponent and offers some interesting new guidelines to the problem of pairing mechanisms in HTS.Comment: 5 pages, 3 figures, RevTex; Accepted for publication in Physical Review B; (figures enlarged

Influence of Poly(L-Lactic Acid) Nanofibers and BMP-2–Containing Poly(L-Lactic Acid) Nanofibers on Growth and Osteogenic Differentiation of Human Mesenchymal Stem Cells

The aim of this study was to characterize synthetic poly-(L-lactic acid) (PLLA) nanofibers concerning their ability to promote growth and osteogenic differentiation of stem cells in vitro, as well as to test their suitability as a carrier system for growth factors. Fiber matrices composed of PLLA or BMP-2–incorporated PLLA were seeded with human mesenchymal stem cells and cultivated over a period of 22 days under growth and osteoinductive conditions, and analyzed during the course of culture, with respect to gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and collagen I (COL-I). Furthermore, COL-I and OC deposition, as well as cell densities and proliferation, were analyzed using fluorescence microscopy. Although the presence of nanofibers diminished the dexamethasone-induced proliferation, there were no differences in cell densities or deposition of either COL-I or OC after 22 days of culture. The gene expression of ALP, OC, and COL-I decreased in the initial phase of cell cultivation on PLLA nanofibers as compared to cover slip control, but normalized during the course of cultivation. The initial down-regulation was not observed when BMP-2 was directly incorporated into PLLA nanofibers by electrospinning, indicating that growth factors like BMP-2 might survive the spinning process in a bioactive form

Semisynthetic Neoclerodanes as Kappa Opioid Receptor Probes

Modification of the furan ring of salvinorin A (1), the main active component of Salvia divinorum, has resulted in novel neoclerodane diterpenes with opioid receptor affinity and activity. Conversion of the furan ring to an aldehyde at the C-12 position (5) has allowed for the synthesis of analogues with new carbon-carbon bonds at that position. Previous methods for forming these bonds, such as Grignard and Stille conditions, have met with limited success. We report a palladium catalyzed Liebeskind-Srogl cross-coupling reaction of a thioester and a boronic acid that occurs at neutral pH and ambient temperature to produce ketone analogs at C-12. To the best of our knowledge, this is the first reported usage of the Liebeskind-Srogl reaction to diversify a natural product scaffold. We also describe a one-step protocol for the conversion of 1 to 12-epi-1 (3) through microwave irradiation. Previously, this synthetically challenging process has required multiple steps. Additionally, we report in this study that alkene 9 and aromatic analogues 12, 19, 23, 25, and 26 were discovered to retain affinity and selectivity at kappa opioid receptors (KOP). Finally, we report that the furan-2-yl analog of 1 (31) has similar affinity to 1. Collectively, these findings suggest that different aromatic groups appended directly to the decalin core may be well tolerated by KOP receptors, and may generate further ligands with affinity and activity at KOP receptors

Effect of Dopant on the Nanostructured Morphology of Poly (1-naphthylamine) Synthesized by Template Free Method

The study reports some preliminary investigations on the template free synthesis of ascantlyinvestigated polyaniline (PANI) derivative—poly (1-naphthylamine) (PNA) by template free method in presence as well as absence of hydrochloric acid (HCl) (dopant), using ferric chloride as oxidant. The polymerization was carried out in alcoholic medium. Polymerization of 1-naphthylamine (NPA) was confirmed by the FT-IR as well as UV–visible studies. The morphology and size of PNA particles was strongly influenced by the presence and absence of acid which was confirmed by transmission electron microscopy (TEM) studies

Search for the exotic Ξ−−(1860)\Xi^{--}(1860) Resonance in 340GeV/c Σ−\Sigma^--Nucleus Interactions

We report on a high statistics search for the $\Xi^{--}(1860)$ resonance in $\Sigma^-$-nucleus collisions at 340GeV/c. No evidence for this resonance is found in our data sample which contains 676000 $\Xi^-$ candidates above background. For the decay channel $\Xi^{--}(1860) \to \Xi^-\pi^-$ and the kinematic range 0.15$<x_F<$0.9 we find a 3$\sigma$ upper limit for the production cross section of 3.1 and 3.5 $\mu$b per nucleon for reactions with carbon and copper, respectively.Comment: 5 pages, 4 figures, modification of ref. 43 and 4

Impacts of traditional food consumption advisories: Compliance, changes in diet and loss of confidence in traditional foods

<p>Abstract</p> <p>Background</p> <p>Food consumption advisories are often posted when industrial activities are expected to affect the quality and availability of traditional foods used by First Nations. We were recently involved in a project and asked to summarize details regarding the impacts of traditional food consumption advisories with respect to compliance, broader changes in diet and loss of confidence in traditional foods by people.</p> <p>Methods</p> <p>Our review was not conducted as a formal systematic comprehensive review; rather, we focused on primary and grey literature presenting academic, health practitioner and First Nations viewpoints on the topic available from literature databases (i.e., PubMed, Web of Knowledge^SM) as well as the internet search engine Google. Some information came from personal communications.</p> <p>Results</p> <p>Our overview suggests that when communicated effectively and clearly, and when community members are involved in the process, consumption advisories can result in a decrease in contaminant load in people. On the other hand, consumption advisories can lead to cultural loss and have been linked to a certain amount of social, psychological, nutritional, economic and lifestyle disruption. In some cases, communities have decided to ignore consumption advisories opting to continue with traditional lifestyles believing that the benefits of doing so outweigh the risk of following advisories.</p> <p>Conclusions</p> <p>We identified that there are both positive and negative aspects to the issuance of traditional food consumption advisories. A number of variables need to be recognized during the development and implementation of advisories in order to ensure a balance between human health, maintenance of cultures and industrial activity.</p

Measurement of the Ds lifetime

We report precise measurement of the Ds meson lifetime. The data were taken by the SELEX experiment (E781) spectrometer using 600 GeV/c Sigma-, pi- and p beams. The measurement has been done using 918 reconstructed Ds. The lifetime of the Ds is measured to be 472.5 +- 17.2 +- 6.6 fs, using K*(892)0K+- and phi pi+- decay modes. The lifetime ratio of Ds to D0 is 1.145+-0.049.Comment: 5 pages, 2 figures submitted to Phys. Lett.

Confirmation of the Double Charm Baryon Xi_cc+ via its Decay to p D+ K-

We observes a signal for the double charm baryon Xi_cc+ in the charged decay mode Xi_cc+ -> p D+ K- to complement the previously reported decay Xi_cc+ -> Lambda_c K- pi+ in data from SELEX, the charm hadro-production experiment (E781) at Fermilab. In this new decay mode we observe an excess of 5.62 events over an expected background estimated by event mixing to be 1.38+/-0.13 events. The Poisson probability that a background fluctuation can produce the apparent signal is less than 6.4E-4. The observed mass of this state is (3518+/-3)MeV/c^2, consistent with the published result. Averaging the two results gives a mass of (3518.7+/-1.7)MeV/c^2. The observation of this new weak decay mode confirms the previous SELEX suggestion that this state is a double charm baryon. The relative branching ratio Gamma(Xi_cc+ -> pD+K-)/Gamma(Xi_cc+ -> Lambda_c K- pi+) = 0.36+/-0.21.Comment: 11 pages, 6 included eps figures. v2 includes improved statistical method to determine significance of observation. Submitted to PL