1,726 research outputs found

    Possibilities for recycling cellulases after use in celllase processing - part I: effects of end-product inhibition, thermal and mechanical deactivation, and cellulase depletion by adsorption

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    Preliminary recycling experiments with cellulase enzymes after cotton treatments at 50°C showed that activity remaining in the treatment liquors was reduced by about 80% after five recycling steps. The potential problems of end-product inhibition, thermal and mechanical deactivation, and the loss of some components of the cellulase complex by preferential and or irreversible adsorption to cotton substrates were studied. End-product inhibition studies showed that the build-up of cellobiose and glucose would be expected to cause no more than 40% activity loss after five textile treatment cycles. Thermal and mechanical treatments of cellulases suggested that the enzymes start to be deactivated at 60°C and agitation levels similar to those used in textile processing did not cause significant enzyme deactivation. Analysis of cellulase solutions, by fast protein liquid chromatography, before and after adsorption on cotton fabrics, suggested that the cellobiohydrolase II (Cel6A) content of the cellulase complex was reduced, relative to the other components, by preferential adsorption. This would lead to a marked reduction in activity after several treatment cycles and top-up with pure cellobiohydrolase II would be necessary unless this component is easily recoverable from the treated fabric

    Possibilities for recycling cellulases after use in cotton processing - part II: Separation of cellulases from reaction products and released dyestuffs by ultrafiltration

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    The adsorption and activity of a total cellulase (Trichoderma reesei) was measured and compared on undyed and dyed cotton fabrics. Recovery of enzymes from the reaction mixture and by desorption from the cotton substrate was evaluated. About 80% of the initial protein could be recovered. The removal of released products (soluble reducing sugars and dyes) from the treatment liquor and subsequent concentration of cellulase proteins was performed using an ultrafiltration membrane. Strong protein-dye interactions made it impossible to separate efficiently the dyes from the enzymecontaining treatment liquors. The use of surfactants did not enhance cellulase desorption from cotton fabric. Although anionic surfactants have a deactivating effect on cellulases, this effect seems to be reversible, since after ultrafiltration the cellulase activity was similar to that of enzymes desorbed with buffer only. Humicola insolens cellulases were shown to be much more sensitive to anionic surfactant than T. reesei cellulases. The use of cellulases that bind reversibly to cellulose is suggested for achieving more efficient cellulase recycling and for reducing backstaining by dye-cellulase complexes

    Effects of agitation level on the adsorption, desorption, and activities on cotton fabrics of full length and core domains of EGV(humicola insolens) and CenA (cellulomonas fimi)

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    The activities (at pH 7 and 50 degrees C) of purified EGV (Humicola insolens) and CenA (Cellulomonas fimi) were determined on cotton fabrics at high and low levels of mechanical agitation. Similar activity measurements were also made by using the core domains of these cellulases. Activity experiments suggested that the presence of cellulose binding domains (CBDs) is not essential for cellulase performance in the textile processes, where high levels of mechanical agitation are applied. The binding reversibilities of these cellulases and their cores were studied by dilution of the treatment liquor after equilibrium adsorption. EGV showed low percentage of adsorption under both levels of agitation. It was observed that the adsorption/desorption processes of cellulases are enhanced by higher mechanical agitation levels and that the binding of cellulase with CBD of family I (EGV) is more reversible than that of CBD of the cellulase of family II (CenA). (C) 2000 Elsevier Science Inc. All rights reserved

    Effects of Sports Compression Socks on Performance, Physiological, and Hematological Alterations After Long-Haul Air Travel in Elite Female Volleyballers

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    Broatch, JR, Bishop, DJ, Zadow, EK, and Halson, S. Effects of sports compression socks on performance, physiological, and hematological alterations after long-haul air travel in elite female volleyballers. J Strength Cond Res 33(2): 492-501, 2019-The purpose of this investigation was to assess the merit of sports compression socks in minimizing travel-induced performance, physiological, and hematological alterations in elite female volleyball athletes. Twelve elite female volleyballers (age, 25 ± 2 years) traveled from Canberra (Australia) to Manila (Philippines), and were assigned to 1 of 2 conditions; compression socks (COMP, n = 6) worn during travel or a passive control (CON, n = 6). Dependent measures included countermovement jump (CMJ) performance, subjective ratings of well-being, cardiovascular function, calf girth, and markers of blood clotting, collected before (-24 hours, CMJ; -12 hours, all measures), during (+6.5 and +9 hours, subjective ratings and cardiovascular function), and after (+12 hours, all measures except CMJ; +24 hours and +48 hours, CMJ) travel. When compared with CON, small-to-large effects were observed for COMP to improve heart rate (+9 hours), oxygen saturation (+6.5 hours and +9 hours), alertness (+6.5 hours), fatigue (+6.5 hours), muscle soreness (+6.5 hours and +9 hours), and overall health (+6.5 hours) during travel. After travel, small-to-moderate effects were observed for COMP to improve systolic blood pressure (+12 hours), right calf girth (+12 hours), CMJ height (+24 hours), mean velocity (+24 hours), and relative power (+48 hours), compared with CON. COMP had no effect on the markers of blood clotting. This study suggests that compression socks are beneficial in combating the stressors imposed by long-haul travel in elite athletes, and may have merit for individuals frequenting long-haul travel or competing soon after flying

    Resolving the Unexpected in Elections: Election Officials\u27 Options

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    This paper seeks to assist election officials and their lawyers in effectively handling the technical issues that can be difficult to understand and analyze, allowing them to protect themselves and the public interest from unfair accusations, inaccuracies in results, and conspiracy theories. The paper helps to empower officials to recognize which types of voting system events and indicators need a more structured analysis and what steps to take to set up the evaluations (or forensic assessments) using computer experts

    Inference by replication in densely connected systems

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    An efficient Bayesian inference method for problems that can be mapped onto dense graphs is presented. The approach is based on message passing where messages are averaged over a large number of replicated variable systems exposed to the same evidential nodes. An assumption about the symmetry of the solutions is required for carrying out the averages; here we extend the previous derivation based on a replica symmetric (RS) like structure to include a more complex one-step replica symmetry breaking (1RSB)-like ansatz. To demonstrate the potential of the approach it is employed for studying critical properties of the Ising linear perceptron and for multiuser detection in Code Division Multiple Access (CDMA) under different noise models. Results obtained under the RS assumption in the non-critical regime give rise to a highly efficient signal detection algorithm in the context of CDMA; while in the critical regime one observes a first order transition line that ends in a continuous phase transition point. Finite size effects are also observed. While the 1RSB ansatz is not required for the original problems, it was applied to the CDMA signal detection problem with a more complex noise model that exhibits RSB behaviour, resulting in an improvement in performance.Comment: 47 pages, 7 figure

    Sports review: A content analysis of the International Review for the Sociology of Sport, the Journal of Sport and Social Issues and the Sociology of Sport Journal across 25 years

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    The International Review for the Sociology of Sport, the Journal of Sport and Social Issues and Sociology of Sport Journal have individually and collectively been subject to a systematic content analysis. By focusing on substantive research papers published in these three journals over a 25-year time period it is possible to identify the topics that have featured within the sociology of sport. The purpose of the study was to identify the dominant themes, sports, countries, methodological frameworks and theoretical perspectives that have appeared in the research papers published in these three journals. Using the terms, identified by the author(s), that appear in the paper’s title, abstract and/or listed as a key word, subject term or geographical term, a baseline is established to reflect on the development of the sub-discipline as represented by the content of these three journals. It is suggested that the findings illustrate what many of the more experienced practitioners in the field may have felt subjectively. On the basis of this systematic, empirical study it is now possible to identify those areas have received extensive coverage and those which are under-researched within the sociology of sport. The findings are used to inform a discussion of the role of academic journals and the recent contributions made by Michael Silk, David Andrews, Michael Atkinson and Dominic Malcolm on the past, present and future of the ‘sociology of sport’
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