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New Domains (new + domain)
Selected AbstractsGeneralization of cluster treatment of characteristic roots for robust stability of multiple time-delayed systemsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 14 2008Rifat Sipahi Abstract A new perspective is presented for studying the stability robustness of nth order systems with p rationally independent delays. It deploys a holographic mapping procedure over the delay space into a new coordinate system in order to achieve the objective. This mapping collapses the entire set of potential stability switching points on a manageably small number of hypersurfaces, which are explicitly defined in the new domain. This property considerably alleviates the problem, which is otherwise infinite dimensional, and therefore notoriously complex to handle. We further declare some unrecognized features of these switching hypersurfaces, that they are (a) encapsulated within a higher-dimensional cube with edges of length 2,, which we name the ,building block', and (b) the ,offspring' of this building block, which represent the secondary stability switchings, appear within the adjacent and identical building blocks (cubes) stacked up next to each other. The final outlook is an exclusive representation of stability for this general class of systems at any arbitrary point in the delay space. Two example case studies are also provided, which are not possible to analyze using any other methodology known to the authors. Copyright © 2007 John Wiley & Sons, Ltd. [source] "Natural restoration" can generate biological complexityCOMPLEXITY, Issue 2 2005Emile ZuckerkandlArticle first published online: 16 DEC 200 Abstract Factor complexes engaged in transcriptional regulation of gene expression and their cognate DNA elements recurrently suffer mutational damage that can result in deadaptations in the mutual fit of interacting macromolecules. Such mutations can spread in populations by drift if their functional consequences are not severe. Mutational restorations of the damaged complexes may ensue and can take many forms. One of these forms would represent spontaneous increases in gene interaction complexity and correlated aspects of organismic complexity. In this particular mode of restoration, restabilization of a factor/factor/DNA complex occurs through the binding of an additional factor. Factors added under such circumstances to regulatory kits of individual genes are thought to be at the origin of a slow but persistent "complexity drive." This drive seems to be resisted in many forms whose developmental outcome has reached a finish line difficult to pass, but imposes itself along other lines of phylogenetic descent. In the process of restoration by an additional factor, the chances are significant that the original regulatory control of a target gene is not recovered exactly and that the restored gene expression has novel spatial, temporal, or quantitative characteristics. These new characteristics, which represent a functional transfer of the gene to a new domain of activity, may be selectable, even when the physicochemical properties of the gene product have remained largely unchanged. As a consequence of such activity transfers under quasi-constancy of the molecular properties of the protein encoded by the regulation's target gene, the activity domain originally covered by that target gene may be left at least in part functionally vacant. At that point, an unmodified duplicate of the target gene and of its original regulatory dependencies probably becomes in turn selectable. A causal link is therefore predicted between the regulatory specialization and selection of one of two duplicates and the regulatory maintenance and selection of the other. A conserved increase in gene number would result indirectly from the regulatory shift in paralogs, and the organism's complexity would be increased in this sense also, complexity as number of genes in addition to complexity as number of regulatory factors per gene. It is thus proposed that increased biological complexity, innovation in the gene regulatory network, and the development of a novel evolutionary potential can be the result, counterintuitively, of conservative forces that intervene when mutations play a survivable form of havoc with the system of gene regulation. Increasing complexity, then, could be seen as one of the side effects of "natural restoration." This phrase designates the mutational re-establishment in the gene whose regulation has been damaged of a functionally effective activity pattern, albeit, perhaps, with changes in its mode of expression in regard to location, time, and rate. The higher complexity, innovation in the gene regulatory network, of higher organisms,their very character of higher organisms,would to a significant extent be a side effect of episodes of natural selection aimed at functional restoration, not at complexity itself. Regulatory impairment, the point of departure of the process outlined, represents a controller gene disease. It thus may well be the case that molecular diseases, the effects on the individual of inheritable structural decay, are among the conditions of the evolution of higher organisms. © 2005 Wiley Periodicals, Inc. Complexity 11: 14,27, 2005 [source] Novel domains of the prokaryotic two-component signal transduction systemsFEMS MICROBIOLOGY LETTERS, Issue 1 2001Michael Y. Galperin Abstract The archetypal two-component signal transduction systems include a sensor histidine kinase and a response regulator, which consists of a receiver CheY-like domain and a DNA-binding domain. Sequence analysis of the sensor kinases and response regulators encoded in complete bacterial and archaeal genomes revealed complex domain architectures for many of them and allowed the identification of several novel conserved domains, such as PAS, GAF, HAMP, GGDEF, EAL, and HD-GYP. All of these domains are widely represented in bacteria, including 19 copies of the GGDEF domain and 17 copies of the EAL domain encoded in the Escherichia coli genome. In contrast, these novel signaling domains are much less abundant in bacterial parasites and in archaea, with none at all found in some archaeal species. This skewed phyletic distribution suggests that the newly discovered complexity of signal transduction systems emerged early in the evolution of bacteria, with subsequent massive loss in parasites and some horizontal dissemination among archaea. Only a few proteins containing these domains have been studied experimentally, and their exact biochemical functions remain obscure; they may include transformations of novel signal molecules, such as the recently identified cyclic diguanylate. Recent experimental data provide the first direct evidence of the participation of these domains in signal transduction pathways, including regulation of virulence genes and extracellular enzyme production in the human pathogens Bordetella pertussis and Borrelia burgdorferi and the plant pathogen Xanthomonas campestris. Gene-neighborhood analysis of these new domains suggests their participation in a variety of processes, from mercury and phage resistance to maintenance of virulence plasmids. It appears that the real picture of the complexity of phosphorelay signal transduction in prokaryotes is only beginning to unfold. [source] The addition of mood and anxiety domains to the University of Washington quality of life scale,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 6 2002Simon N. Rogers FDS Abstract Background There are numerous head and neck specific quality of life questionnaires, each having its own merits and disadvantages. The University of Washington questionnaire has been widely used and is notable by the inclusion of a shoulder dysfunction domain, domain importance ratings, and patient free text. It is short, simple to process, and provides clinically relevant information. However, it has lacked any psychological dimension of quality of life. The aim of this study was to report the inclusion of two psychological domains (mood, anxiety) to the most recent refinement of the questionnaire (version 3). Method A cross-sectional survey was performed in April 2000. Questionnaires were sent to 183 patients alive and disease free after surgery for oral and oro-pharyngeal malignancy. Replies were received from 145 patients (79% response rate). Results The new domains (mood and anxiety) correlated significantly with the emotional functioning domains from the EORTC C30 and with the pain and appearance domains of UW-QOL. There were also significant correlations between the "global quality of life" item and the two new domains. Mood (p = .005) and anxiety (p < .001) scores were associated with patient age but with no other clinicodemographic variable. Conclusion The addition of mood and anxiety domains makes the UW-QOL version 4 a single broad measure suitable for effective health-related quality of life evaluation in the routine clinical setting. © 2002 Wiley Periodicals, Inc. Head Neck 24: 521,529, 2002 [source] Primitive complement system of invertebratesIMMUNOLOGICAL REVIEWS, Issue 1 2004Masaru Nonaka Summary:, Most components of the human complement system have unmistakable domain architectures, making evolutionary tracing feasible. In contrast to the major genes of the adaptive immune system, which are present only in jawed vertebrates, complement component genes with unique domain structures are present not only in jawed vertebrates but also in jawless fish and non-vertebrate deuterostomes. Recent progress in genome analysis in several eukaryotes, occupying the phylogenetically critical positions, showed that most individual domains found in the complement components are metazoa specific, being found both in deuterostomes and in protostomes but not in yeast or plant. However, unique domain architecture of complement components is not present in protostomes, suggesting that the complement system has been established in the deuterostome lineage not by invention of new domains but by innovation of unique combination of the pre-existing domains. The recently assembled Ciona intestinalis draft genome contained the most modular complement genes, except for factor I. However, some possible C. intestinalis complement components show critical structural divergence from the mammalian counterparts, casting doubt on their mutual interaction. Thus, another integrative step seems to have been required to establish the modern complement system of higher vertebrates. [source] ORIGINAL RESEARCH,ERECTILE DYSFUNCTION: Journey into the Realm of Requests for Help Presented to Sexual Medicine Specialists: Introducing Male Sexual DistressTHE JOURNAL OF SEXUAL MEDICINE, Issue 3 2007Edoardo S. Pescatori MD ABSTRACT Introduction., The recent availability of noninvasive pharmacological remedies for male sexual function triggered an exponential increase in the number of men requesting help in the sexuality area. Aim., The Italian Society of Andrology explored requests for help, not included in formerly established clinical categories of sexual medicine. Methods., A central board of 67 andrologists identified new areas of requests for help, instrumental for a web-based questionnaire, forwarded to 912 members of the Italian Society of Andrology. Results were submitted to an independent consensus development panel. Main Outcome Measures., A questionnaire response rate of 30.8% was considered acceptable according to standard response rates of medical specialist samples. Results., The Central Board interaction identified two new domains of requests for help: sexual distress and unconventional requests for pro-erectile medications. Web-based questionnaire results suggested that such domains account for 29% and 9% respectively of all requests for help already presented by male patients at sexual medicine clinics. The Independent Consensus Development Panel issued a final consensus document; herewith, the statement defining male sexual distress: A non-transitory condition and/or feeling of inadequacy such as to impair "sexual health" (WHO working definition). Inadequacy can originate both from physiological modifications of male sexual functions, and from diseases, dysfunctions, dysfunctional symptoms and dysmorphisms, both of andrological and non-andrological origin, which do not relate to "erectile dysfunction" (NIH Consensus Development Panel definition), but that might also induce erectile dysfunction. Sexual Distress can lead to a request for help which needs to be acknowledged. Conclusion., The Italian Society of Andrology identified two new areas of requests for help concerning male sexual issues: sexual distress and unconventional requests for pro-erectile medications. These domains, which do not represent new diseases, nonetheless induce the sufferers to seek help and, accordingly, need to be acknowledged. Pescatori ES, Giammusso B, Piubello G, Gentile V, and Pirozzi Farina F. Journey into the realm of requests for help presented to sexual medicine specialists: Introducing male sexual distress. J Sex Med 2007;4:762,770. [source] | ||||||||||