DELINEATION OF TRACKS OF HEAVY COSMIC RAYS AND NUCLEAR PROCESSES WITHIN LARGE SILVER CHLORIDE CRYSTALS

Delineation of tracks of heavy cosmic rays and nuclear processes with in large silver chloride crystal

The effect of signal acquisition and processing choices on ApEn values: Towards a “gold standard” for distinguishing effort levels from isometric force records

Approximate Entropy (ApEn) is frequently used to identify changes in the complexity of isometric force records with ageing and disease. Different signal acquisition and processing parameters have been used, making comparison or confirmation of results difficult. This study determined the effect of sampling and parameter choices by examining changes in ApEn values across a range of submaximal isometric contractions of the First Dorsal Interosseus. Reducing the sample rate by decimation changed both the value and pattern of ApEn values dramatically. The pattern of ApEn values across the range of effort levels was not sensitive to the filter cut-off frequency, or the criterion used to extract the section of data for analysis. The complexity increased with increasing effort levels using a fixed ‘r’ value (which accounts for measurement noise) but decreased with increasing effort level when ‘r’ was set to 0.1 of the standard deviation of force. It is recommended isometric force records are sampled at frequencies >200 Hz, template length (‘m’) is set to 2, and 'r' set to measurement system noise or 0.1 SD depending on physiological process to be distinguished. It is demonstrated that changes in ApEn across effort levels are related to changes in force gradation strategy

The Virtual Teacher (VT) Paradigm: Learning New Patterns of Interpersonal Coordination Using the Human Dynamic Clamp

The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities

Effects of Acute Cytomegalovirus Infection on Rat Islet Allograft Survival

Transplantation of pancreatic islets is a promising therapy for the treatment of type 1 diabetes mellitus. However, long-term islet graft survival rates are still unsatisfactory low. In this study we investigated the role of cytomegalovirus (CMV) in islet allograft failure. STZ-diabetic rats received an allogenic islet graft in combination with either an acute CMV infection or control infection. A third group received ganciclovir treatment in addition to the CMV infection. Graft function was assessed by measuring basal blood glucose levels. After sacrifice, the islet grafts were retrieved for analysis of infection and leukocyte infiltration. CMV-infected recipients demonstrated accelerated islet graft failure compared to noninfected controls. CMV infection of the graft was only observed prior to complete graft failure. Quantification of the leukocyte infiltration demonstrated increased CD8(+) T-cell and NK cell infiltration in the CMV-infected grafts compared to the controls. This suggests that CMV infection accelerates immune-mediated graft destruction. Antiviral ganciclovir treatment did not prevent accelerated graft failure, despite effectively decreasing the grade of infection. Our data confirm the recently published CITR data, which state that CMV is an independent risk factor for failure of islet grafts. Also, our data demonstrate that new approaches for preventing virus-induced islet allograft failure may be required

A novel antimicrobial lectin from Eugenia malaccensis that stimulates cutaneous healing in mice model

Objective The present work reports the purification and partial characterization of an antibacterial lectin (EmaL) obtained from Eugenia malaccensis seeds as well as the evaluation of its effect in the daily topical treatment of repairing process of cutaneous wounds in mice. Materials and methods The cutaneous wound was produced by the incision of the skin and use of lectin in the treatment of mice cutaneous wounds was evaluated. Surgical wounds were treated daily with a topical administration of EmaL and parameters such as edema, hyperemia, scab, granulation and scar tissues as well as contraction of wounds were analyzed. Results A novel lectin, with a molecular mass of 14 kDa, was isolated from E. malaccensis using affinity chromatography. The lectin (EmaL) agglutinated glutaraldehyde-treated rabbit and human erythrocytes; the lectin-induced rabbit erythrocyte agglutination was inhibited by glucose, casein, ovalbumin and fetuin. Also, Emal was very effective in the inhibition of bacterial growth, with the best inhibition results obtained for Staphylococcus aureus. Inflammatory signals such as edema and hyperemia were statistically less intense when EmaL was applied compared to the control. The histopathological analysis showed that the treated injured tissue presented reepithelialization (complete or partial) and areas of transition more evidenced than those of the control group, especially due to well organized pattern of collagen fibers presented in the granulation fibrous tissue. Conclusion Presented results are a preliminary indication of the pharmacological interest in using EmaL as antimicrobial agent and in the repairing process of cutaneous wounds.This paper was financially supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), FACEPE and CAPES, Brazil. The authors are deeply grateful for the technical assistance of Maria Barbosa Reis da Silva and João Antonio Virgínio and Alfa/VALNATURA Project.info:eu-repo/semantics/publishedVersio

INTERACTIONS OF POINT DEFECTS WITH DISLOCATIONS AND SURFACES IN SILVER HALIDE CRYSTALS

Deux aspects d'interactions de défauts sont discutés dans AgCl et AgBr. 1) L'établissement d'un équilibre entre les crans chargés (sur les surfaces et dislocations) et les défauts ponctuels produit des charges superficielles, régions de charge d'espace, et des variations locales dans le potentiel électrique et la concentration de défaut. La localisation et l'environnement des crans jouent un rôle important dans la détermination de la nature de la charge d'espace. Dans les halogénures d'argent, l'impact de ces effets sur les processus photographiques est discuté. Les informations actuelles sur les charges d'espace aux surfaces et dislocations sont décrites ; alors que la production d'un Ag- interstitiel nécessite moins d'énergie qu'une lacune sur un cran, l'opposé peut être vrai sur une dislocation. 2) Des techniques de frottement interne ont été utilisées pour étudier la liaison entre des solutés et les dislocations. Dans AgCl, l'énergie de liaison est approximativement 0,2 eV. Après une légère perturbation de l'atmosphère de Maxwell autour d'une dislocation, la réorganisation suit une loi en t 1/3 ; un modèle simple donne cette dépendance ainsi que la valeur correcte de l'énergie d'activation. Des études semblables dans AgBr cependant ont montré un régime étrange où la constante de vitesse de réorganisation a une énergie d'activation négative. La grandeur de cet effet et le domaine de température dépendent de la concentration en dopant. Il n'existe pas d'explication simple à l'heure actuelle.Two aspects of defect interactions in AgCl and AgBr are discussed. 1) The establishment of equilibrium between charged jogs (on surfaces and dislocations) and point defects produces surface charges, space charge regions, and local changes in electric potential and defect concentration. The locus and environment of the jogs play a large role in determining the nature of the space charge. For the silver halides, irnplications of these effects to the photographic process are discussed. The available information on the space charges at surfaces and dislocations in both AgBr and AgCl is surveyed ; it is seen that whereas it is energetically cheaper to produce an interstitial Ag+ than a vacancy at a surface jog, the opposite may be true at dislocations. 2) Internal friction techniques have been used to study the binding of solutes to dislocations. In AgCl, the binding energy is approximately 0.2 eV. After a srnall perturbation of the Maxwell atmosphere around the dislocation, the recovery follows a t1/3 law ; a simple model yields this dependence, and also the correct activation energy. Similar studies in AgBr, however, have revealed a strange regime in which the rate constant for recovery has a negative activation energy, the magnitude and temperature range of the effect depending on concentration of dopant. No simple explanation is yet available