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Parallel Development (parallel + development)
Selected AbstractsThemes of liver transplantation,HEPATOLOGY, Issue 6 2010Thomas E. Starzl Liver transplantation was the product of five interlocking themes. These began in 1958-1959 with canine studies of then theoretical hepatotrophic molecules in portal venous blood (Theme I) and with the contemporaneous parallel development of liver and multivisceral transplant models (Theme II). Further Theme I investigations showed that insulin was the principal, although not the only, portal hepatotrophic factor. In addition to resolving long-standing controversies about the pathophysiology of portacaval shunt, the hepatotrophic studies blazed new trails in the regulation of liver size, function, and regeneration. They also targeted inborn metabolic errors (e.g., familial hyperlipoproteinemia) whose palliation by portal diversion presaged definitive correction with liver replacement. Clinical use of the Theme II transplant models depended on multiple drug immunosuppression (Theme III, Immunology), guided by an empirical algorithm of pattern recognition and therapeutic response. Successful liver replacement was first accomplished in 1967 with azathioprine, prednisone, and antilymphoid globulin. With this regimen, the world's longest surviving liver recipient is now 40 years postoperative. Incremental improvements in survival outcome occurred (Theme IV) when azathioprine was replaced by cyclosporine (1979), which was replaced in turn by tacrolimus (1989). However, the biologic meaning of alloengraftment remained enigmatic until multilineage donor leukocyte microchimerism was discovered in 1992 in long-surviving organ recipients. Seminal mechanisms were then identified (clonal exhaustion-deletion and immune ignorance) that linked organ engraftment and the acquired tolerance of bone marrow transplantation and eventually clarified the relationship of transplantation immunology to the immunology of infections, neoplasms, and autoimmune disorders. With this insight, better strategies of immunosuppression have evolved. As liver and other kinds of organ transplantation became accepted as healthcare standards, the ethical, legal, equity, and the other humanism issues of Theme V have been resolved less conclusively than the medical-scientific problems of Themes I-IV. HEPATOLOGY 2010 [source] Regulation of T-cell receptor signalling by membrane microdomainsIMMUNOLOGY, Issue 4 2004Tahir M. Razzaq Summary There is now considerable evidence suggesting that the plasma membrane of mammalian cells is compartmentalized by functional lipid raft microdomains. These structures are assemblies of specialized lipids and proteins and have been implicated in diverse biological functions. Analysis of their protein content using proteomics and other methods revealed enrichment of signalling proteins, suggesting a role for these domains in intracellular signalling. In T lymphocytes, structure/function experiments and complementary pharmacological studies have shown that raft microdomains control the localization and function of proteins which are components of signalling pathways regulated by the T-cell antigen receptor (TCR). Based on these studies, a model for TCR phosphorylation in lipid rafts is presented. However, despite substantial progress in the field, critical questions remain. For example, it is unclear if membrane rafts represent a homogeneous population and if their structure is modified upon TCR stimulation. In the future, proteomics and the parallel development of complementary analytical methods will undoubtedly contribute in further delineating the role of lipid rafts in signal transduction mechanisms. [source] Embryonic reversions and lineage infidelities in tumour cells: genome-based models and role of genetic instabilityINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 2 2005Leon P. Bignold Summary Reversions to ,embryonic precursor'-type cells and infidelities of tumour cell lineage (including metaplasias) have been recognized as aspects of various tumour types since the 19th century. Since then, evidence of these phenomena has been obtained from numerous clinical, biochemical, immunological and molecular biological studies. In particular, microarray studies have suggested that ,aberrant' expressions of relevant genes are common. An unexplained aspect of the results of these studies is that, in many tumour types, the embryonic reversion or lineage infidelity only occurs in a proportion of cases. As a parallel development during the molecular biological investigation of tumours over the last several decades, genetic instability has been found much more marked, at least in some preparations of tumour cells, than that identified by means of previous karyotypic investigations of tumours. This study reviews examples of embryonic reversion and lineage infidelity phenomena, which have derived from the various lines of investigation of cancer over the last 150 or so years. Four categories of circumstances of the occurrence of embryonic reversions or lineage infidelities have been identified , (i) as part of the defining phenotype of the tumour, and hence being presumably integral to the tumour type, (ii) present ab initio in only some cases of the tumour type, and presumably being regularly associated with, but incidental to, the essential features of the tumour type, (iii) occurring later in the course of the disease and thus being possibly a manifestation of in vivo genetic instability and ,tumour progression' and (iv) arising probably by genetic instability, during the processes, especially cell culture, associated with ex vivo investigations. Genomic models are described which might account for the origin of these phenomena in each of these circumstances. [source] Biological images of geological history: through a glass darkly or brightly face to face?JOURNAL OF BIOGEOGRAPHY, Issue 2 2003Jeremy D. Holloway Abstract Aim, To explore the implications for historical biogeography of a recent review of island biogeographical theory in three main thematic areas and to suggest ways in which a synthesis between the two approaches might be achieved to the benefit of both. Location, The Indo-Australian tropics. Theme 1, discusses the relationship of species number to area, and how the nestedness of faunas may influence the methodology used for some types of analysis and also the quality of data expected from an archipelago embracing an extreme range of island sizes. Theme 2, examines the way in which the processes of speciation may lead to development of biogeographical patterns through a complex archipelago, illustrated in particular with reference to Sulawesi where biotic enrichment from different lepidopteran groups follows predictions from island biogeographical theory. This also has implications for patterns of endemism in the archipelago, another constraint on the quality of data available for historical biogeography. Theme 3, addresses ecological determinism as an influence in development of biogeographical pattern, focusing on the theme of specificity in insect,plant relationships and the potential for parallel development of pattern in an insect group and its particular plant host group. This theme is developed with particular reference to moth and plant groups that may represent Gondwanan elements in the Oriental fauna, with an analysis of Sarcinodes, a geometrid moth genus associated with Proteaceae. Main conclusions, Prospects are assessed for the synthesis of the two approaches of island biogeography and historical biogeography. Modelling pattern development with the former may complement the methods of analysis of the latter, particularly if some satisfactory method for dating events of pattern development can also be incorporated. [source] Postcolonial Transitions in Africa: Decolonization in West Africa and Present Day South AfricaJOURNAL OF MANAGEMENT STUDIES, Issue 5 2010Stephanie Decker abstract Black Economic Empowerment is a highly debated issue in contemporary South Africa. Yet few South Africans realize that they are following a postcolonial trajectory already experienced by other countries. This paper presents a case study of British firms during decolonization in Ghana and Nigeria in the 1950s and 1960s, which saw a parallel development in business and society to that which occurred in South Africa in the 1990s and 2000s. Despite fundamental differences between these states, all have had to empower a majority of black citizens who had previously suffered discrimination on the basis of race. The paper employs concepts from social capital theory to show that the process of postcolonial transition in African economies has been more politically and socially disruptive than empowerment in Western countries. Historical research contributes to our understanding of the nature of institutional shocks in emerging economies. [source] Information Technology and Adult Learners at Empire State CollegeNEW DIRECTIONS FOR STUDENT SERVICES, Issue 102 2003Patricia J. Lefor Successful introduction of technology-delivered education to adult students can be enhanced by attention to program development, reliance on easy-to-use technology readily available to a wide range of students, and the parallel development of online learner supports and student services. [source] Barnacle culture: background, potential and challengesAQUACULTURE RESEARCH, Issue 10 2010Daniel A. López Abstract There are approximately a dozen species of commercially interesting barnacles worldwide, some of which have been cultured on a semi-industrial scale. These species are listed and information is provided with regard to geographical distribution, landings and prices. Traditionally, ,goose' barnacles (four species) are considered to be the most important for consumption. World production already stands at 500 tonnes year,1, but this species has not been cultured to date. Some ,acorn' barnacles are also consumed (seven species), with harvest levels per species that do not exceed 200 tonnes year,1 and selling prices that can reach US$17/kg. ,Acorn' barnacle culture on a world scale is still developing. Nevertheless, production has occurred on a semi-industrial scale; specifically, spat have been collected from the wild and grown in suspended systems. Farming trials have focused on two species of acorn barnacles: Austromegabalanus psittacus (Molina 1782) ,picoroco' in Chile and Megabalanus azoricus (Pilsbry 1916) ,craca' in Portugal. The large-scale production of these crustaceans will depend on the optimization of spat collection from the wild and/or the parallel development of mass production technologies for larvae (hatcheries). In addition, further development will be achieved by opening up new markets for commercialization. [source] Grapevine genetics after the genome sequence: Challenges and limitationsAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2010J.M. MARTÍNEZ-ZAPATER Abstract The publication of the genome sequences of inbred grapevine plant PN40024 and the cultivar Pinot Noir has provided a new generation of molecular tools and has opened the way to functional genomics in grapevine. Establishing gene biological function is now a major challenge requiring the parallel development of molecular and genetic information. New massive pyrosequencing technologies will ensure no shortage of nucleotide sequence information. However, genetic analysis and genetic tools in grapevine still require additional development. Exploiting the existing natural genetic variation in Vitis vinifera L. and other inter-fertile Vitis species should be a priority to focus functional analyses on genes contributing to phenotypic variation because their genetic variation constitutes the basis for genetic improvement of classical cultivars and for the development of new ones. In this review, we discussed the current molecular and genetic tools available in grapevine and considered those that need to be developed to exploit natural genetic variation in the analyses of gene function. We also reviewed the scarce information on the genetic and molecular structure of relevant grapevine traits and proposed future directions. [source] Morphology and morphogenesis of ensiform leaves, syndesmy of shoots and an understanding of the thalloid plant body in species of Apinagia, Mourera and Marathrum (Podostemaceae)BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2005IRMGARD JÄGER-ZÜRN The flattened, irregularly shaped and lobed or dissected leaves of Apinagia riedelii, A. latifolia, A. goejei, Mourera aspera and Marathrum utile (subfamily Podostemoideae) are ensiform in structure. After the typical bifacial inception, further growth of leaves proceeds in the midrib area, i.e. in the median plane of the leaf. The lower leaf zone is characterized by a sheath that orientates ,at the side of the blade', i.e. at the adaxial edge of the sword-like leaf. The ensiform blades are lobed, incised or pinnately dissected with the tips terminated in elongated threads or thin filaments. Leaves of Apinagia riedelii resemble pinnately dissected compound leaves. The dissected structure represents a secondary superimposition of the ensiform shape and a parallel development to compound leaves. It is interpreted as an adaptation to the rapid current, established in the floating shoots of these aquatic plants. The basal portions of main shoots and successive branches are fused due to a retarded separation. Fusion of this kind has been termed a syndesmy. The fused region of shoots is superseded by the fusion of the lower leaf zones of (distichously positioned) adjacent leaves, occurring at their margins. The fused leaf bases form a cavity for the terminal flower bud of each shoot and cover it in the form of a hood. The flower buds are hidden from external view. The meristematic growing zones are thus protected and enclosed within the syndesmic plant body which, in this way, attains the ,thalloid' appearance especially developed in Apinagia goejei and A. latifolia but also present in the other species. The results of this study enable an understanding of the particular appearance of these Podostemoideae as modifications of the typical structures according to the ,principle of variable proportions'. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147, 47,71. [source] Magnifying Superlenses and other Applications of Plasmonic Metamaterials in Microscopy and SensingCHEMPHYSCHEM, Issue 4 2009Igor I. Smolyaninov Dr. Abstract Every last detail: New advances in the construction of metamaterials enable the creation of artificial optical media, whose use in microscopy can provide resolution that is not determined by the conventional diffraction limit. The picture shows a superposition of an AFM image of a plasmonic metamaterial onto the corresponding optical image obtained using a conventional optical microscope. Over the past century, the resolution of conventional optical microscopes, which rely on optical waves that propagate into the far field, has been limited because of diffraction to a value of the order of a half-wavelength (,0/2) of the light used. Although immersion microscopes have slightly improved resolution, of the order of ,0/2n, the increased resolution is limited by the small range of refractive indices n of available transparent materials. However, now we are experiencing a quick demolition of the diffraction limit in optical microscopy. In the last few years, numerous nonlinear optical microscopy techniques based on photoswitching and saturation of fluorescence have demonstrated far-field resolution of 20 to 30 nm. In a parallel development, recent progress in metamaterials has demonstrated that artificial optical media can be created, whose use in microscopy can provide resolution that is not determined by the conventional diffraction limit. The resolution of linear immersion microscopes based on such metamaterials is only limited by losses, which can be minimized by appropriate selection of the constituents of the metamaterials used and by the wavelength(s) used for imaging. It is also feasible to compensate for losses by adding gain to the structure. Thus, optical microscopy is quickly moving towards resolution of around 10 nm, which should bring about numerous revolutionary advances in lithography and imaging. [source] Targeting gold at the end of the rainbow: Surgical gamma probes in the 21st centuryJOURNAL OF SURGICAL ONCOLOGY, Issue 4 2007Frederick L. Moffat Jr MD Abstract Surgical gamma detection probes (GDPs) have become important in the surgical management of neoplastic disease in the past 20 years. Their history and radiophysics are discussed, with consideration of the overarching issue of tumor-to-background ratio (TBR). GDPs are currently most commonly used in sentinel node applications in a variety of tumors. Whether their role in clinical surgical practice can be extended to other applications will depend on the development of radiolabeled tumor marking agents which have much improved TBR, and parallel developments in oncology research which may overtake this technology. J. Surg. Oncol. 2007;96:286,289. © 2007 Wiley-Liss, Inc. [source] Genomics and systems biology , how relevant are the developments to veterinary pharmacology, toxicology and therapeutics?JOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2005R. F. WITKAMP This review discusses some of the recent developments in genomics and its current and future relevance for veterinary pharmacology and toxicology. With the rapid progress made in this field several new approaches in pharmacological and toxicological research have developed and drug discovery and drug development strategies have changed dramatically. In this review, the term genomics is used to encompass the three sub-disciplines transcriptomics, proteomics and metabolomics (or metabonomics) to describe the formation and fate of mRNA, proteins and metabolites, respectively. The current status and methods of the technology and some applications are briefly described. Although the DNA sequencing programmes are receiving considerable attention, the real value of genomics for pharmacology and toxicology is brought by the parallel developments in bio-informatics, bio-statistics and the integration of biology with mathematics and information technology. The ultimate level of integration is now mostly called systems biology, where mRNA, proteins and metabolites are being analysed in parallel, using a complete arsenal of analytical techniques (DNA-array, LC-MS/MS, GC-MS/MS, NMR, etc.). The information thus collected is analysed, integrated, linked to database information and translated to pathways and systems. This approach offers an enormous potential to study disease mechanisms and find new drug targets. Thus far, genomics and systems biology have not been introduced significantly in typical veterinary pharmacological and toxicological research programmes. The high costs and complexity connected to these large projects often form major obstacles for research groups with limited budgets. In other veterinary areas and disciplines, including infectious diseases, animal production and food-safety more examples of application are available. Genomics and bio-informatics provide outstanding opportunities to study pharmacology and toxicology in a more holistic way, taking into account the complexity of biological systems and based on the basic principles of physiology and the concept of homeostasis. Knowledge of biology, in vivo and in vitro models, and comparative pharmacology/toxicology is essential here, creating excellent opportunities for the veterinary trained scientist. [source] What Happened to Gender Relations on the Way from Chicago to Los Angeles?CITY & COMMUNITY, Issue 2 2002Daphne Spain From the Chicago human ecologists to the Los Angeles postmodernists, urban theorists have tried to understand how space is structured by technological, political, economic, and cultural forces; gender is seldom examined. Yet both women's status and urban form underwent significant changes following World War II. As the home became less predictably the center of women's lives, the monocentric city was evolving into the polycentric metropolis. This article suggests that gender relations also have spatial implications for the metropolis, and that urban theory would be more comprehensive if it incorporated historically parallel developments in the literature on gender and space. [source] | ||||||||||||||||