44 resultados para Retaining
Resumo:
Initially this thesis examines the various mechanisms by which technology is acquired within anodizing plants. In so doing the history of the evolution of anodizing technology is recorded, with particular reference to the growth of major markets and to the contribution of the marketing efforts of the aluminium industry. The business economics of various types of anodizing plants are analyzed. Consideration is also given to the impact of developments in anodizing technology on production economics and market growth. The economic costs associated with work rejected for process defects are considered. Recent changes in the industry have created conditions whereby information technology has a potentially important role to play in retaining existing knowledge. One such contribution is exemplified by the expert system which has been developed for the identification of anodizing process defects. Instead of using a "rule-based" expert system, a commercial neural networks program has been adapted for the task. The advantages of neural networks over 'rule-based' systems is that they are better suited to production problems, since the actual conditions prevailing when the defect was produced are often not known with certainty. In using the expert system, the user first identifies the process stage at which the defect probably occurred and is then directed to a file enabling the actual defects to be identified. After making this identification, the user can consult a database which gives a more detailed description of the defect, advises on remedial action and provides a bibliography of papers relating to the defect. The database uses a proprietary hypertext program, which also provides rapid cross-referencing to similar types of defect. Additionally, a graphics file can be accessed which (where appropriate) will display a graphic of the defect on screen. A total of 117 defects are included, together with 221 literature references, supplemented by 48 cross-reference hyperlinks. The main text of the thesis contains 179 literature references. (DX186565)
Resumo:
Microbial transglutaminase is favoured for use in industry over the mammalian isoform, and hence has been utilized, to great effect, as an applied biocatalyst in many industrial areas including the food and textiles industries. There are currently only a limited number of microbial TGase sources known. A number of organisms have been screened for transglutaminase activity using biochemical assays directed towards TGase catalyzed reactions (amine incorporation and peptide cross-linking assay). Of those organisms screened, TGase was identified in a number of isolates including members of the Bacillus and Streptomyces families. In addition, a protein capable of performing a TGase-like reaction was identified in the organism Pseudomonas putida that was deemed immunologically distinct from previously described TGase isoforms, though further work would be required to purify the protein responsible. The genuses Streptoverticillium and Streptomyces are known to be closely related. A number of micro-organisms relating to Streptomyces mobaraensis (formerly Streptoverticillium mobaraensis) have been identified as harboring a TGase enzyme. The exact biological role of Streptomyces TGase is not well understood, though from work undertaken here it would appear to be involved in cell wall growth. Comparison of the purified Streptomyces TGase proteins showed them to exhibit marginally different characteristics in relation to enzymatic activity and pH dependency upon comparison with Streptomyces mobaraensis TGase. In addition, TGase was identified in the organism Saccharomonospora viridis that was found to be genetically identical to that from S. mobaraensis raising questions about the enzymes dissemination in nature. TGase from S. baldaccii was found to be most diverse with respect to enzymatic characteristics whilst still retaining comparable E(y-glutamyl) lysine bond formation to S. mobaraensis TGase. As such S. baldaccii TGase was cloned into an expression vector enabling mass production of the enzyme thereby providing a viable alternative to S. mobaraensis TGase for many industrial processes.
Resumo:
Despite abundant literature on human behaviour in the face of danger, much remains to be discovered. Some descriptive models of behaviour in the face of danger are reviewed in order to identify areas where documentation is lacking. It is argued that little is known about recognition and assessment of danger and yet, these are important aspects of cognitive processes. Speculative arguments about hazard assessment are reviewed and tested against the results of previous studies. Once hypotheses are formulated, the reason for retaining the reportory grid as the main research instrument are outlined, and the choice of data analysis techniques is described. Whilst all samples used repertory grids, the rating scales were different between samples; therefore, an analysis is performed of the way in which rating scales were used in the various samples and of some reasons why the scales were used differently. Then, individual grids are looked into and compared between respondents within each sample; consensus grids are also discussed. the major results from all samples are then contrasted and compared. It was hypothesized that hazard assessment would encompass three main dimensions, i.e. 'controllability', 'severity of consequences' and 'likelihood of occurrence', which would emerge in that order. the results suggest that these dimensions are but facets of two broader dimensions labelled 'scope of human intervention' and 'dangerousness'. It seems that these two dimensions encompass a number of more specific dimensions some of which can be further fragmented. Thus, hazard assessment appears to be a more complex process about which much remains to be discovered. Some of the ways in which further discovery might proceed are discussed.
Resumo:
Basic literacy skills are fundamental building blocks of education, yet for a very large number of adults tasks such as understanding and using everyday items is a challenge. While research, industry, and policy-making is looking at improving access to textual information for low-literacy adults, the literacy-based demands of today's society are continually increasing. Although many community-based organizations offer resources and support to adults with limited literacy skills, current programs have difficulties reaching and retaining those that would benefit most from them. To address these challenges, the National Research Council of Canada is proposing a technological solution to support literacy programs and to assist low-literacy adults in today's information-centric society: ALEX© – Adult Literacy support application for EXperiential learning. ALEX© has been created together with low-literacy adults, following guidelines for inclusive design of mobile assistive tools. It is a mobile language assistant that is designed to be used both in the classroom and in daily life, in order to help low-literacy adults become increasingly literate and independent.
Resumo:
Periodontitis, a ubiquitous chronic inflammatory disease, is associated with reduced antioxidant defences and neutrophil hyperactivity in terms of reactive oxygen species (ROS) generation. Its phenotype is thus characterized by oxidative stress. We have determined the effect of antioxidant micronutrients ascorbate and α-tocopherol on neutrophil ROS generation. Peripheral neutrophils from periodontally-healthy individuals (n = 20) were challenged with phorbol myristate acetate, IgG-opsonised Staphylococcus aureus, Fusobacterium nucleatum or PBS in the presence and absence of micronutrients (50 μM). Total and extracellular ROS were measured by luminol and isoluminol chemiluminescence respectively. Total and extracellular unstimulated, baseline ROS generation was unaffected by α-tocopherol, but inhibited by ascorbate and a combination of both micronutrients. Fcγ-receptor (Fcγ-R)-stimulated total or extracellular ROS generation was not affected by the presence of individual micronutrients. However, the combination significantly reduced extracellular FcγR-stimulated ROS release. Neither micronutrient inhibited TLR-stimulated total ROS, but the combination caused inhibition. Ascorbate and the micronutrient combination, but not α-tocopherol, inhibited extracellular ROS release by TLR-stimulated cells. Such micronutrient effects in vivo could be beneficial in reducing collateral tissue damage in chronic inflammatory diseases, such as periodontitis, while retaining immune-mediated neutrophil function. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Resumo:
A major challenge in text mining for biomedicine is automatically extracting protein-protein interactions from the vast amount of biomedical literature. We have constructed an information extraction system based on the Hidden Vector State (HVS) model for protein-protein interactions. The HVS model can be trained using only lightly annotated data whilst simultaneously retaining sufficient ability to capture the hierarchical structure. When applied in extracting protein-protein interactions, we found that it performed better than other established statistical methods and achieved 61.5% in F-score with balanced recall and precision values. Moreover, the statistical nature of the pure data-driven HVS model makes it intrinsically robust and it can be easily adapted to other domains.
Resumo:
Optometrists play an important part in delivering eye care in the United Kingdom; however opportunities for practitioners to extend their role through co-management of patients with ophthalmologists vary across the country. Devolution in Scotland and Wales has led to greater emphasis on community based care in these regions. This thesis reviews the current situation and, by examining ophthalmic outpatient clinic data, discusses further opportunities to reduce demands on secondary care and the cost savings that can be made. To assess whether the profession is currently in a position to adopt an extended clinical role, changes in the availability of optometric instrumentation are assessed over a two year period. An increased prevalence of fundus cameras and contact tonometers places optometrists in a good position to take on further responsibilities in glaucoma management, however future investment could be impacted by the current economic climate as value for money became increasingly important to practitioners looking to purchase equipment. Methods of training optometrists in the necessary skills to utilise new technology to extend their role are evaluated in terms of both learning and cost effectiveness. Interactive distance learning is proposed as a convenient and effective method to deliver continuing professional development. Any changes to optometric practice must take account of the need for a sustainable business and the importance of attracting and retaining patients. The views of patients are assessed through a validated service quality questionnaire, SERVQUAL. The questionnaire is found to be valid for use in an optometry setting. Patients have a generally positive view of the service quality they receive from their optical practice and consider the intangible aspects, in particular responsiveness and empathy, most important. Optometrists are well placed to increase their role in patient management; however a viable business model must exist to enable investment in instrumentation and training.
Resumo:
A main unsolved problem in the RNA World scenario for the origin of life is how a template-dependent RNA polymerase ribozyme emerged from short RNA oligomers obtained by random polymerization on mineral surfaces. A number of computational studies have shown that the structural repertoire yielded by that process is dominated by topologically simple structures, notably hairpin-like ones. A fraction of these could display RNA ligase activity and catalyze the assembly of larger, eventually functional RNA molecules retaining their previous modular structure: molecular complexity increases but template replication is absent. This allows us to build up a stepwise model of ligation- based, modular evolution that could pave the way to the emergence of a ribozyme with RNA replicase activity, step at which information-driven Darwinian evolution would be triggered. Copyright © 2009 RNA Society.
Resumo:
For a very large number of adults, tasks such as reading. understanding, and using everyday items are a challenge. Although many community-based organizations offer resources and support for adults with limited literacy skills. current programs have difficulty reaching and retaining those that would benefit most. In this paper we present the findings of an exploratory study aimed at investigating how a technological solution that addresses these challenges is received and adopted by adult learners. For this, we have developed a mobile application to support literacy programs and to assist low-literacy adults in today's information-centric society. ALEX© (Adult Literacy support application for Experiential learning) is a mobile language assistant that is designed to be used both in the classroom and in daily life in order to help low-literacy adults become increasingly literate and independent. Through a long-term study with adult learners we show that such a solution complements literacy programs by increasing users' motivation and interest in learning, and raising their confidence levels both in their education pursuits and in facing the challenges of their daily lives.
Resumo:
We propose and demonstrate novel virtual Gires-Tournois (GT) etalons based on fiber gratings. By introducing an additional phase modulation in wideband linearly chirped fiber Bragg gratings, we have successfully generated GT resonance with only one grating. This technique can simplify the fabrication procedure while retaining the normal advantages of distributed etalons, including their full compatibility with optical fiber, low insertion loss, and low cost. Such etalons can be used as dispersion compensation devices in optical transmission systems. © 2007 Optical Society of America.
Resumo:
In this paper we will demonstrate the improved BER performance of doubly differential phase shift keying in a coherent optical packet switching scenario while still retaining the benefits of high frequency offset tolerance. © OSA 2014.
Resumo:
This research study illustrates the importance of sustainable purchasing practices for organizations in the U.S. distribution industry and answers several important questions: what is the current awareness of U.S. organizations regarding sustainable purchasing practices; to what extent are U.S. organizations evaluating, selecting, and retaining suppliers based upon sustainable purchasing practices; and to what extent are sustainable purchasing practices being implemented by the U.S. organizations under study? With an ever increasing global economy, is it critically important for organizations to put in place sustainability practices; the biggest impact organizations can make is often in an organization’s purchasing department. The researcher begins by explaining the reasoning for conducting the research, and then builds the readers’ understanding of sustainability in a supply chain environment. It then moves to the subject of how sustainable purchasing can be an advantageous method for bringing about “triple bottom line” savings to an organization. This section is followed by the researcher’s methodology and ending results for a survey conducted to examine the current awareness and implementation of sustainable purchasing practices among U.S. plumbing, heating, cooling and piping (PHCP) distribution firms who participated in the study.
A polyoxometallate-tethered Ru complex as a catalyst in solventless phenyl acetylene oligomerisation
Resumo:
A novel compound comprising a Ru–tethered polyoxometallate Keggin anion of formula [HNEt3]+[(Ru{η5-C5H5}{PPh3}2)2(PW12O40)]− has been synthesised that shows high activity and selectivity in alkyne oligomerisation. In situ IR binding studies using CO confirmed the accessibility of the Ru centre for catalysis. Phenyl acetylene was successfully dimerised under a heterogeneous catalytic regime. Selectivity towards the (E)-enyne, not found in the homogeneous Ru(η5-C5H5)(PPh3)2Cl analogue, was achieved while retaining high a turnover frequency of 225 h−1.
Resumo:
Descriptions of vegetation communities are often based on vague semantic terms describing species presence and dominance. For this reason, some researchers advocate the use of fuzzy sets in the statistical classification of plant species data into communities. In this study, spatially referenced vegetation abundance values collected from Greek phrygana were analysed by ordination (DECORANA), and classified on the resulting axes using fuzzy c-means to yield a point data-set representing local memberships in characteristic plant communities. The fuzzy clusters matched vegetation communities noted in the field, which tended to grade into one another, rather than occupying discrete patches. The fuzzy set representation of the community exploited the strengths of detrended correspondence analysis while retaining richer information than a TWINSPAN classification of the same data. Thus, in the absence of phytosociological benchmarks, meaningful and manageable habitat information could be derived from complex, multivariate species data. We also analysed the influence of the reliability of different surveyors' field observations by multiple sampling at a selected sample location. We show that the impact of surveyor error was more severe in the Boolean than the fuzzy classification. © 2007 Springer.
Resumo:
We propose a novel approach to pulse shaping using a phase-modulated fiber Bragg gratings (FBGs) in transmission. This enables the simplification of the device fabrication while retaining the substantial advantages of FBGs in transmission. © 2013 OSA.