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Many Decades (many + decade)
Selected AbstractsA comparative study of student performance in traditional mode and online mode of learningCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2007Qiping Shen Abstract There has been interest for many decades in comparing the effectiveness of technology-delivered instruction with traditional face-to-face teaching and measurable student outcomes have been an important indicator. Having pointed to salient aspects of the current academic environment and to some of the key literature in this area, this article analyses the performance of two groups of students studying in the traditional mode and the online mode in a masters program delivered by a Department of Computing at a university in Hong Kong. Over 2,000 students have participated in the study between 2000 and 2004. This article includes a comparison of the results between different delivery modes of study each year as well as between different classes over the 4-year period. Although traditional mode students have achieved a slightly better performance in examinations in comparison with online mode students, the article concludes that there are no significant differences in overall performance between the students. With the impact of technologies on higher education and the demands of a complex and rapidly changing society in the 21st century, this Hong Kong study contributes to the literature that finds mode of study is not a key determinant of success. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ 15: 30,40, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20092 [source] Mechanisms of exercise-induced improvements in the contractile apparatus of the mammalian myocardiumACTA PHYSIOLOGICA, Issue 4 2010O. J. Kemi Abstract One of the main outcomes of aerobic endurance exercise training is the improved maximal oxygen uptake, and this is pivotal to the improved work capacity that follows the exercise training. Improved maximal oxygen uptake in turn is at least partly achieved because exercise training increases the ability of the myocardium to produce a greater cardiac output. In healthy subjects, this has been demonstrated repeatedly over many decades. It has recently emerged that this scenario may also be true under conditions of an initial myocardial dysfunction. For instance, myocardial improvements may still be observed after exercise training in post-myocardial infarction heart failure. In both health and disease, it is the changes that occur in the individual cardiomyocytes with respect to their ability to contract that by and large drive the exercise training-induced adaptation to the heart. Here, we review the evidence and the mechanisms by which exercise training induces beneficial changes in the mammalian myocardium, as obtained by means of experimental and clinical studies, and argue that these changes ultimately alter the function of the whole heart and contribute to the changes in whole-body function. [source] Bench-scale evaluation of in situ bioremediation strategies for soil at a former manufactured gas plant siteENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2005Jun Li Abstract We examined the biodegradation and desorption of a set of 15 polycyclic aromatic hydrocarbon (PAH) compounds in coal tar,contaminated soil at a former manufactured gas plant site to evaluate the feasibility of in situ bioremediation. Experiments were conducted in well-mixed aerobic soil suspensions containing various additives over a 93- to 106-d period. In general, both biotransformation and desorption decreased with PAH ring size, becoming negligible for the six-ring PAH compounds. Biodegradation by indigenous microorganisms was strongly accelerated by addition of inorganic nutrients (N, P, K, and trace metals). The rates of biotransformation of PAH compounds by indigenous microorganisms in nutrient-amended flasks outpaced their maximum (i.e., chelate-enhanced) rates of desorption to an infinite sink (Tenax®) in sterilized systems run in parallel, suggesting that indigenous organisms facilitated desorption. Biodegradation by indigenous organisms in nutrient-amended flasks appeared to be unaffected by the addition of a site-derived bacterial enrichment culture, resulting in approximately 100-fold higher aromatic dioxygenase levels, and by the addition of 0.01 M chelating agent (citrate or pyrophosphate), although such chelating agents greatly enhanced desorption in microbially inactivated flasks. The strong ability of nutrients to enhance degradation of the bioavailable PAHs indicates that their persistence for many decades at this site likely results from nutrient-limited natural biodegradation, and it also suggests that an effective strategy for their bioremediation could consist simply of adding inorganic nutrients. [source] Hippocampal Malformations Do Not Necessarily Evolve into Hippocampal SclerosisEPILEPSIA, Issue 6 2005Arjune Sen Summary:,Purpose: Hippocampal malformations have been proposed to underlie or evolve into hippocampal sclerosis, a common cause of refractory partial epilepsy. We report two patients with chronic epilepsy and developmental abnormalities of the hippocampus and cortex. We seek to address, in patients with recurrent convulsive seizures over many decades, whether hippocampal malformations necessarily progress to hippocampal sclerosis. Methods: The first patient died at age 76 years and had experienced convulsive seizures for 43 years. The second patient, aged 64 years at death, had experienced convulsive seizures for 49 years. The brains were processed routinely. Immunohistochemistry for dynorphin and neuropeptide Y was performed. Results: The first case exhibited bilateral perisylvian polymicrogyria. Both hippocampi demonstrated abnormal convolution in the CA1 subfield and subiculum. In the second case, periventricular heterotopia was found in the wall of the right lateral ventricle. The right hippocampus was abnormally oriented with excessive convolutions of the pyramidal cell layer between CA1 and the subiculum. In neither patient did the hippocampi exhibit neuronal loss. Furthermore, dynorphin immunohistochemistry revealed no reactivity in the molecular layers, and staining with neuropeptide Y confirmed normal numbers of hilar interneurons. Conclusions: These two cases demonstrate histologically that, even in long-standing epilepsy, malformations of the hippocampus do not necessarily develop into hippocampal sclerosis. [source] Autoantibodies in alcoholic liver diseaseADDICTION BIOLOGY, Issue 2 2000Ian G. McFarlane Despite many decades of research, the reasons why only a relatively small proportion of individuals who consume excessive quantities of alcohol develop clinically significant liver disease remain unknown. The association with features of autoimmune diseases, including hypergammaglobulinaemia, circulating autoantibodies, inheritance of certain immunogenetic (HLA) markers and response to corticosteroid therapy in some patients has led to a persistent impression that altered immune regulation with a relative loss of self-tolerance underlies susceptibility to the development of the more severe forms of alcoholic liver disease (alcoholic hepatitis and/or cirrhosis). However, review of the data from the numerous studies that have been conducted over the past 30 years fails to reveal sufficiently convincing evidence that autoimmunity plays a primary role in alcohol-related liver damage. In particular, most of the wide range of circulating autoantibodies that have been reported in patients are found mainly at low titres, are not confined to those with severe liver injury, and are probably more likely to be a response to the hepatic insult than causally related to liver damage. Additionally, an association with various HLA phenotypes has not been confirmed by meta-analysis. Interpretation is complicated by evidence that alcohol may have direct effects on some components of the immune system but, if there is an immunogenetic basis for alcoholic liver disease, the present evidence suggests that this might be related more to cytokine gene polymorphisms than to a predisposition to autoimmunity per se. [source] Neuropeptide Y in the olfactory microvillar cellsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2006Giorgia Montani Abstract This paper examines a possible role of microvillar cells in coordinating cell death and regeneration of olfactory epithelial neurons. The olfactory neuroepithelium of mammals is a highly dynamic organ. Olfactory neurons periodically degenerate by apoptosis and as a consequence of chemical or physical damage. To compensate for this loss of cells, the olfactory epithelium maintains a lifelong ability to regenerate from a pool of resident multipotent stem cells. To assure functional continuity and histological integrity of the olfactory epithelium over a period of many decades, apoptosis and regeneration require to be precisely coordinated. Among the factors that have been implicated in mediating this regulation is the neuropeptide Y (NPY). Knockout mice that lack functional expression of this neurogenic peptide show defects in embryonic development of the olfactory epithelium and in its ability to regenerate in the adult. Here we show that, in postnatal olfactory epithelia, NPY is exclusively expressed by a specific population of microvillar cells. We previously characterized these cells as a novel type of putative chemosensory cells, which are provided with a phosphatidyl-inositol-mediated signal transduction cascade. Our findings allow for the first time to suggest that microvillar cells are involved in connecting apoptosis to neuronal regeneration by stimulus-induced release of NPY. [source] The role of ultraviolet radiation in melanomagenesisEXPERIMENTAL DERMATOLOGY, Issue 2 2010Anna-Katharina Von Thaler Please cite this paper as: The role of ultraviolet radiation in melanomagenesis. Experimental Dermatology 2010; 19: 81,88. Abstract:, The role of ultraviolet radiation (UV) in the pathogenesis has been discussed controversially for many decades. Studies in mice (SCID, HGF/SF, SV40T) which develop malignant melanoma, show a role of UVB in melanomagenesis. In contrast to this, the role of UVA is less clear. We will review the recent in vitro and in vivo data in support of the hypothesis that UVA is also involved in the development of malignant melanoma. The role of UVA in p53 activation, apoptosis, cell cycle arrest and photoproduct formation is discussed. [source] Dothistroma (red-band) needle blight of pines and the dothistromin toxin: a reviewFOREST PATHOLOGY, Issue 3 2004R. E. Bradshaw Summary Dothistroma (red-band) needle blight has been a problem in plantations of exotic pines in the southern hemisphere for many decades. The prevalence of this disease is currently increasing in the northern hemisphere and is now affecting trees in their native ranges. The fungal pathogen Mycosphaerella pini with its anamorph Dothistroma pini, which is responsible for the disease, produces a toxin, dothistromin, that is closely related to the potent carcinogen, aflatoxin. Understandably this has provoked concern about possible effects on the health of forestry workers. This review gives a broad coverage of literature on both disease and toxin. The fungus has a complicated taxonomy with many synonyms and in most countries only the anamorph is found. It is a necrotrophic pathogen that kills needle tissue and completes its life cycle in the lesion thus formed. Dispersal of the disease is normally by rain splash of conidiospores but there is evidence that long range dispersal has occurred by transport of contaminated plant tissue and by wind/cloud dispersal of spores in air currents. The severity of disease is affected by humidity, temperature and light. There is variation in susceptibility of different Pinus species and some achieve increased resistance with age. The current method of control in southern hemisphere plantation forests is through spraying with copper fungicides and, with P. radiata, increased disease resistance has been achieved through a breeding programme. The dothistromin toxin is a difuroanthraquinone and is similar in structure to the aflatoxin precursor versicolorin B. Part of a gene cluster encoding dothistromin biosynthetic genes has been cloned and this has confirmed parallels between the dothistromin and aflatoxin biosynthetic pathways. Dothistromin produces damaging oxygen radicals by reductive oxygen activation rather than by photosensitization, but is also thought to exert its toxic effects on specific cellular targets. Studies have shown that dothistromin is a weak mutagen and clastogen and is therefore a potential carcinogen. Although the risks to forest workers are considered very low it is prudent to avoid unnecessary exposure during periods when dothistromin levels are likely to be at their peak. Résumé La maladie des bandes rouges causée par Dothistroma est un problème dans les plantations de pins exotiques de l'hémisphère sud depuis de nombreuses années. La prévalence de cette maladie est en augmentation dans l'hémisphère nord et affecte maintenant les pins dans leurs régions d'origine. Le champignon pathogène Dothistroma pini, responsable de la maladie, produit une toxine, la dothistromine, proche de l'aflatoxine qui est un puissant carcinogène. Ceci pose donc la question des effets possibles sur la santé des travailleurs forestiers. Cette revue repose sur une large couverture de la littérature concernant aussi bien la maladie que la toxine. Le champignon a une taxonomie complexe avec de nombreux synonymes, et seul l'anamorphe se rencontre dans de nombreux pays. C'est un champignon nécrotrophe qui tue les tissus de l'aiguille et réalise son cycle biologique dans la lésion ainsi formée. La dissémination de la maladie s'effectue principalement par éclaboussures de pluie contenant les conidies mais une dissémination à longue distance a été mise en évidence par transport de matériel contaminé ou par dissémination des spores par le vent ou les nuages dans les courants aériens. La sévérité de la maladie est affectée par l'humidité, la température et la lumière. Il existe des différences de sensibilité entre espèces de Pinus, et certaines présentent une résistance accrue avec l'âge. La méthode actuelle de lutte dans les forêts de plantations de l'hémisphère sud consiste à pulvériser des fongicides à base de cuivre ; dans le cas de Pinus radiata, une augmentation de la résistance a été obtenue grâce à un programme d'amélioration génétique. La toxine dothistromine est une difuroanthraquinone, similaire en structure à la versicolorine B, précurseur de l'aflatoxine. Une partie d'une batterie de gènes comprenant des gènes de biosynthèse de la dothistromine a été clonée, confirmant les analogies entre les voies de biosynthèse de la dothistromine et de l'aflatoxine. La dothistromine produit des radicaux oxygène nocifs par activation de la réduction de l'oxygène plutôt que par photosensibilisation, mais ses effets toxiques s'exercent aussi probablement sur des sites cellulaires spécifiques. Des études montrent que la dothistromine est un mutagène et clastogène faible, et donc potentiellement carcinogène. Bien que les risques pour les ouvriers forestiers soient considérés comme très faibles, il est prudent d'éviter dans la mesure du possible de s'exposer dans les périodes où les niveaux de dothistromine sont supposés élevés. Zusammenfassung Die Dothistroma -Nadelbräune ist in der Südhemisphäre in Plantagen mit exotischen Kiefernarten seit vielen Jahren ein Problem. In der Nordhemisphäre nimmt die Bedeutung dieser Krankheit derzeit zu und sie befällt nun Bäume auch in ihren natürlichen Verbreitungsgebieten. Der Erreger ist der Ascomycet Mycosphaerella pini (Anamorphe: Dothistroma pini). Der Pilz bildet das Toxin Dothistromin, das eng mit dem hochtoxischen Karzinogen Aflatoxin verwandt ist. Daraus ergab sich die Frage nach möglichen Nebenwirkungen dieser Baumkrankheit auf die Gesundheit von Waldarbeitern. Dieser Review fasst die Information über die Krankheit und das Toxin zusammen. Der Pilz hat eine komplizierte Taxonomie mit vielen Synonymen und in den meisten Ländern wurde nur die Anamorphe nachgewiesen. Er ist ein nekrotrophes Pathogen, das Blattgewebe abtötet, und in den so gebildeten Läsionen seinen Lebenszyklus abschliesst. Der normale Ausbreitungsweg der Krankheit erfolgt über Konidiosporen mit Regentropfen, aber es gibt auch Hinweise auf einen Ferntransport mit infiziertem Pflanzenmaterial und über die Verbreitung von Sporen mit dem Wind bzw. Wolken in Luftströmungen. Die Krankheitsintensität wird durch Luftfeuchte, Temperatur und Licht beeinflusst. Es gibt Unterschiede in der Anfälligkeit zwischen verschiedenen Kiefernarten und manche davon werden mit zunehmendem Alter resistenter. Derzeit werden in Plantagen der südlichen Hemisphäre Kupferfungizide zur Kontrolle dieser Krankheit eingesetzt und für Pinus radiata wurde in Züchtungsprogrammen eine erhöhte Resistenz erreicht. Das Toxin Dothistromin ist ein Difuroanthrachinon und ähnelt in seiner Struktur dem Aflatoxin-Präkursor Versicolorin B. Ein Teil des Genclusters, das die Dothistromin-Biosynthese codiert, wurde geklont, und es wurden dabei Parallelen zwischen dem Dothistromin- und dem Aflatoxin-Biosyntheseweg bestätigt. Dothistromin bildet schädliche Sauerstoffradikale (wahrscheinlich eher durch reduktive Sauerstoffaktivierung als durch Photosensibilisierung), es dürfte aber auch auf spezifische Zellkomponenten toxisch wirken. Dothistromin zeigt schwache mutagene und chromosomenschädigende Wirkungen und ist deshalb ein potentielles Karzinogen. Obwohl das Risiko für Waldarbeiter als gering eingeschätzt wird, sollte man in Perioden, in denen der Dothistromingehalt hoch sein dürfte, eine unnötige Exposition vermeiden. [source] Are diatoms good integrators of temporal variability in stream water quality?FRESHWATER BIOLOGY, Issue 4 2008ISABELLE LAVOIE Summary 1. Although diatoms have been used for many decades for river monitoring around the world, studies showing evidence that diatoms integrate temporal variability in water chemistry are scarce. 2. The purpose of this study was to evaluate the response of the Eastern Canadian Diatom Index (IDEC: Indice Diatomées de l'Est du Canada) with respect to temporal water chemistry variability using three different spatio-temporal data sets. 3. Along a large phosphorus gradient, the IDEC was highly correlated with averaged water chemistry data. Along within-stream phosphorus gradients, the IDEC integrated phosphorus over various periods of time, depending on the trophic status of the site studied (Boyer, Nicolet or Ste. Anne river) and variability in nutrient concentration. 4. In the Ste. Anne River, where nutrient concentrations were low and generally stable, an input of phosphorus induced a rapid change in diatom community structure and IDEC value within the following week. In the mesotrophic Nicolet River, the observed integration period was approximately 2 weeks. Diatom communities in the eutrophic Boyer River appeared to be adapted to frequent and significant fluctuations in nutrient concentrations. In this system, the IDEC therefore showed a slower response to short term fluctuations and integrated nutrient concentrations over a period of 5 weeks. 5. Our results suggest that the integration period varies as a function of trophic status and nutrient concentration variability in the streams. Oligotrophic streams are more sensitive to nutrient variations and their diatom communities are directly altered by nutrient increase, while diatom communities of eutrophic rivers are less sensitive to nutrient fluctuations and major variations take a longer time to be integrated into index values. 6. The longer integration period in the eutrophic environment may be attributed to the complexity of the diatom community. The results from this study showed that the diversity and evenness of the communities increased with trophic status. [source] Is management by objectives obsolete?GLOBAL BUSINESS AND ORGANIZATIONAL EXCELLENCE, Issue 4 2009William F. Roth Management by Objectives has been part of corporate dogma for many decades. But as its touted strengths rapidly become liabilities in the new global century, more empowering and flexible approaches sprout up as promising new models for performance management. The author examines the dampening effect Management by Objectives can have on creativity, teamwork, and the ability to respond to changes in the business. He also presents two cases of organizations that broke out of the mold: W.L. Gore and Associates' innovative approach to self-managing teams and Bridgeport Paper Company's even bolder experiment, in which employees developed and implemented a team-based organizational structure and team-directed processes for decision making, hiring and promotion, training, performance management (without MBO), rewards, and cross-team communication and integration. © 2009 Wiley Periodicals, Inc. [source] UVB phototherapy and skin cancer risk: a review of the literatureINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 5 2005Ernest Lee MD Background, UVB phototherapy is a common treatment modality for psoriasis and other skin diseases. Although UVB has been in use for many decades, many clinicians are hesitant to use this type of phototherapy because of concern over increasing the skin cancer risk. Over the past 20 years, numerous studies have been published examining this issue, but a consensus or analysis of the skin cancer risk is required for the dermatologist to make an educated risk,benefit analysis. Objective, To assess the risk of skin cancer associated with UVB phototherapy. Methods, All prospective or retrospective studies were identified in MEDLINE from 1966 to June 2002. Bibliographies were searched to identify any additional studies examining this issue. All studies that attempted to quantify or qualify any additional skin cancer risk from UVB phototherapy were included. Study selection was performed by two independent reviewers. Results, Eleven studies (10 of which concerned psoriasis patients), involving approximately 3400 participants, were included. Of note, three of the studies involved the same cohort: members of the 16-center US Psoralen plus UVA (PUVA) Follow-up Study. Other than the most recent Finnish study, all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers, and found an increased rate of genital tumors associated with UVB phototherapy, although this study has not been duplicated. Conclusion, The evidence suggests that UVB phototherapy remains a very safe treatment modality. [source] Positively negative: the impact of negativity upon the political consumerINTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 4 2008Jenny LloydArticle first published online: 15 OCT 200 For years there has been an ongoing debate as to the role and impact that ,marketing' has had on politics. Yet, it is the case that many of the concepts associated with the field of marketing have real relevance and have, in fact, been employed within the field of political campaigning for many decades. This is an empirical paper that focuses upon the concept of political brands and the impact that current trends in campaign strategy, and in particular the growth and continued use of negative campaigning, have upon them. Using a constructivist grounded theory approach, the implications associated with such activity are examined and, in particular, its effect upon the consumer/brand relationship. Within the consideration of the results, it becomes clear that political brands' use of negative campaigning is somewhat shortsighted; offering short-term gains but at the cost of long-term damage not only to their brand image but also to the wider democratic system as it stands. In a search for political ,brands' that more effectively meet their needs, there appears a tendency for political consumers to now look outside of the conventional political sector. The emergent concept of the ,negative brand' is explored together with the implications for political consumers, political brands and the wider field of conventional party politics. Copyright © 2007 John Wiley & Sons, Ltd. [source] The changing profile of caravanners in AustraliaINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 1 2006Bruce Prideaux Abstract Caravanning has been a popular leisure activity in Australia for many decades. In recent years the profile of the industry has changed with a shift from family caravanning to retirees. This change has significant implications for the industry overall as well as the regional areas visited by caravanners. This paper reports on research designed to develop a profile of contemporary caravanning in Australia. One of the most significant findings was the homogeneity of the respondents. The largest groups of respondents were ,empty nesters', people who were retired or near retirement and who were attracted to three clusters of activities: nature; shopping and eating; and visiting heritage attractions. Another major finding of interest for regional areas was the relatively low daily expenditure on food and accommodation. The paper discusses a range of options that may be used by regional areas to boost their caravan sector. Copyright © 2006 John Wiley & Sons, Ltd. [source] Bioremediation of polycyclic aromatic hydrocarbons: current knowledge and future directionsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2005Selina M Bamforth Abstract Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds that have accumulated in the natural environment mainly as a result of anthropogenic activities such as the combustion of fossil fuels. Interest has surrounded the occurrence and distribution of PAHs for many decades due to their potentially harmful effects to human health. This concern has prompted researchers to address ways to detoxify/remove these organic compounds from the natural environment. Bioremediation is one approach that has been used to remediate contaminated land and waters, and promotes the natural attenuation of the contaminants using the in situ microbial community of the site. This review discusses the variety of fungi and bacteria that are capable of these transformations, describes the major aerobic and anaerobic breakdown pathways, and highlights some of the bioremediation technologies that are currently available. Copyright © 2005 Society of Chemical Industry [source] Lysosomal sequestration of amine-containing drugs: Analysis and therapeutic implicationsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2007Allyn M. Kaufmann Abstract Amine-containing drugs represent a very important class of therapeutic agents, with the majority of all drugs containing at least one basic nitrogen. For many decades, it has been known that weakly basic compounds can be sequestered into acidic organelles such as lysosomes. Some amines can achieve very high concentrations and induce a dramatic expansion (vacuolization) of the compartment. In the early 70s, Nobel laureate and discoverer of lysosomes, Christian de Duve et al. wrote an elegant commentary describing the theoretical basis for lysosomal sequestration of amines, referring to the process as pH-partitioning and the substrates as lysosomotropics. Recently, a resurgence of interest in the intracellular distribution of drugs has occurred considering its therapeutic importance. Specifically, lysosomal sequestration of amines has received considerable attention for reasons including its involvement in drug resistance, inducement of phospholipidosis, and its influence on whole body distribution/pharmacokinetics. Moreover, the sequestration phenomenon has been recently exploited in the development of a novel drug targeting strategy. This review will focus on these occurrences/developments and conclude with a commentary on the expected impact that knowledge regarding the intracellular distribution of drugs will likely have on future drug development processes. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 729,746, 2007 [source] Free Rotational Diffusion of Rigid Particles with Arbitrary Surface Topography: A Brownian Dynamics Study Using Eulerian AnglesMACROMOLECULAR THEORY AND SIMULATIONS, Issue 2-3 2008Tom Richard Evensen Abstract Rotational diffusion of rigid bodies is an important topic that has attracted sustained interest for many decades, but most existing studies are limited to particles with simple symmetries. Here, we present a simple Brownian dynamics algorithm that can be used to study the free rotational diffusion of rigid particles with arbitrary surface topography. The main difference between the new algorithm and previous algorithms is how the numerical values of the mobility tensor are calculated. The only parameters in the numerical algorithm that depend on particle shape are the principal values of the particle rotational mobility tensor. These three scalars contain all information about the surface topography that is relevant for the particle rotational diffusion. Because these principal values only need to be pre-calculated once, the resulting general algorithm is highly efficient. The algorithm is valid for arbitrary mass density distribution throughout the rigid body. In this paper, we use Eulerian angles as the generalized coordinates describing the particle angular orientation. [source] The evolution of secondary metabolism , a unifying modelMOLECULAR MICROBIOLOGY, Issue 5 2000Richard D. Firn Why do microbes make secondary products? That question has been the subject of intense debate for many decades. There are two extreme opinions. Some argue that most secondary metabolites play no role in increasing the fitness of an organism. The opposite view, now widely held, is that every secondary metabolite is made because it possesses (or did possess at some stage in evolution) a biological activity that endows the producer with increased fitness. These opposing views can be reconciled by recognizing that, because of the principles governing molecular interactions, potent biological activity is a rare property for any molecule to possess. Consequently, in order for an organism to evolve the rare potent, biologically active molecule, a great many chemical structures have to be generated, most of which will possess no useful biological activity. Thus, the two sides of the debate about the role and evolution of secondary metabolism can be accommodated within the view that the possession of secondary metabolism can enhance fitness, but that many products of secondary metabolism will not enhance the fitness of the producer. It is proposed that secondary metabolism will have evolved such that traits that optimize the production and retention of chemical diversity at minimum cost will have been selected. Evidence exists for some of these predicted traits. Opportunities now exist to exploit these unique properties of secondary metabolism to enhance secondary product diversity and to devise new strategies for biotransformation and bioremediation. [source] Arabidopsis pathology breathes new life into the necrotrophs-vs.-biotrophs classification of fungal pathogensMOLECULAR PLANT PATHOLOGY, Issue 4 2004RICHARD P. OLIVER SUMMARY Fungal plant pathologists have for many decades attempted to classify pathogens into groups called necrotrophs, biotrophs and, more recently, hemibiotrophs. Although these terms are well known and frequently used, disagreements about which pathogens fall into which classes, as well as the precise definition of these terms, has conspired to limit their usefulness. Dogmas concerning the properties of the classes have been progressively eroded. However, the genetic analysis of disease resistance, particularly in the model plant Arabidopsis thaliana, has provided a biologically meaningful division based on whether defence against fungal pathogens is controlled via the salicylate or jasmonate/ethylene pathways. This mode-of-defence division distinguishes necrotrophs and biotrophs but it limits the biotroph class to pathogens that possess haustoria. The small number and limited range of pathogens that infect Arabidopsis means that several interesting questions are still unanswered. Do hemibiotrophs represents a distinct class or a subclass of the necrotrophs? Does the division apply to other plant families and particularly to cereals? and does this classification help us understand the intricacies of either fungal pathogenicity or plant defence? [source] Magnetic fields in white dwarfs and stellar evolutionMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2004Christopher A. Tout ABSTRACT The surface magnetic field strengths observed in the magnetic Ap, Bp stars (100,20 000 G) and in the high field magnetic white dwarfs (106,109 G) cover many decades but nevertheless the range of magnetic fluxes observed in each of these stellar groups is similar. An evolutionary link between them therefore appears plausible. For both groups of stars there is also information on field complexity. The magnetic white dwarfs in general show non-dipole field structures which can be best modelled if we assume contributions from higher order multipoles. The field structures of the Ap and Bp stars are similarly complex. We investigate the hypothesis that the magnetic fields of the white dwarfs could be fossil remnants from the main-sequence phase by focussing on the problem of how field complexity may arise and be maintained during evolution to the compact star state. We also address the question of to what extent magnetic fields seen in the early type stars could be fossil remnants from the pre-main-sequence phases of stellar evolution dating back perhaps to the time of star formation. [source] World Oil Reserves: Problems In Definition And EstimationOPEC ENERGY REVIEW, Issue 4 2000Ghazi M. Haider Various controversial issues relating to the definition and interpretation of the term ,proven reserves' are cited and discussed. Furthermore, reserve figures published in oil industry periodicals and trade journals are reviewed and analyzed. ,Original reserves' (reserves plus cumulative production) of non-OPEC countries seem to increase almost linearly with time, especially since the early 1980s, with an average rate of rise of 15 billion barrels per annum. The OPEC trend, however, is rather ,distorted' by irregular revisions, and the rate of additions to reserves in non-OPEC countries seems to have surpassed OPEC countries during the 1990s. Nevertheless, OPEC, with its easily accessible low-cost oil, will very likely continue to be the paramount source of world oil for many decades. [source] Fish consumption and body burden of organochlorines among lower hudson urban anglersAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2008Kimberly Morland PhD Abstract Background Polychlorinated biphenyls and other organochlorines have contaminated the Hudson River and New York/New Jersey Harbor for many decades. Although body burdens and health effects resulting from exposure to these pollutants have been measured in other populations, little is known about anglers from the lower Hudson area. Methods Anglers were recruited from fishing clubs and along piers on the lower Hudson River. One hundred twenty-five participants provided blood samples and questionnaire information. Serum was analyzed at Mount Sinai School of Medicine for organochlorines. Results Mean concentration of total PCB congeners was 4.78 µg/L. A non-significant adjusted mean difference of ,0.59 µg/L was observed between local fish eaters and non-eaters with higher levels among the non-eaters. Similar negative, but non-significant associations were observed for p,p'-DDT, HCB, and ,-BHC. For pp'-DDE, and several chlordane residues, levels were higher among anglers reporting local fish consumption, but the difference was statistically significant only for TN. Conclusions These findings suggest eating fish from the lower Hudson River and NY/NJ harbor is not associated with an increased body burden of PCBs or most other organochlorines. Am. J. Ind. Med. 51:587,594, 2008. © 2008 Wiley-Liss, Inc. [source] The demographic transition revisited as a global processPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2004David S. Reher Abstract With dramatic declines in fertility taking place throughout the world, it is increasingly important to understand the demographic transition as a global process. While this universality was a cornerstone of classic transition theories, for many decades it was largely neglected by experts because fertility in the developing world did not seem to follow the expected pattern. When comparing earlier and more recent transition experiences, important similarities and disparities can be seen. Everywhere mortality decline appears to have played a central role for fertility decline. The differences in the timing of the response of fertility to mortality decline, with very small gaps historically and prolonged ones in more recent transitions, plus the much more rapid decline in vital rates in many developing countries, constitute an important challenge to any general explanation of the process. The specific characteristics of recent transitions have led to decades of higher population growth rates, and promise to give way to much more rapid dynamics of population ageing in many countries. This may limit the ability of newcomers to take full advantage of the demographic transition for the social and economic modernisation of their societies. Copyright © 2004 John Wiley & Sons, Ltd. [source] Proteome analysis of human foetal, aged and advanced nuclear cataract lensesPROTEOMICS - CLINICAL APPLICATIONS, Issue 12 2008Peter G. Hains Abstract The most complete proteome of human lenses has been compiled using 2-D LC-MS/MS analysis of foetal, aged normal and advanced nuclear cataract lenses. A total of 231 proteins were identified across all lens groups, including 112 proteins that have not been reported previously. Proteins were grouped according to their PANTHER molecular function classification in order to facilitate comparisons. Previously unreported N-terminal acetylation was detected in a number of proteins, with the majority being associated with the prior removal of a methionine residue. This pattern of proteolysis may indicate that methionine aminopeptidase activity is present in human lenses. Acetylation is likely to aid in the stability of proteins that are present in the lens for many decades. Protein sequences were also used to interrogate the three human lens cDNA libraries publicly available. Surprisingly, 84 proteins we identified were not present in the cDNA libraries. [source] Citizen Participation in Budgeting TheoryPUBLIC ADMINISTRATION REVIEW, Issue 3 2006Carol Ebdon Citizen participation in government budgeting processes is a topic that has received attention for many decades. Despite prescriptive exhortations to cities, research in this area has significant limitations. We identify four elements that are believed to influence the participation process. The variables within each element have received attention in the empirical literature, but no systematic effort has been made to uncover interaction effects and extend theory to make it more robust. We consider the weaknesses of our knowledge, suggest an impact model of citizen participation in budgeting, and identify hypotheses that may be tested in future research. [source] Temporal and Spatial Distribution of the Cannabinoid Receptors (CB1, CB2) and Fatty Acid Amide Hydroxylase in the Rat OvaryTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2010P. Bagavandoss Abstract Although the effects of ,9 -tetrahydrocannabinol (THC) on ovarian physiology have been known for many decades, its mechanism of action in the rat ovary remains poorly understood. The effects of THC and endocannabinoids on many cell types appear to be mediated through the G-protein-coupled CB1 and CB2 receptors. Evidence also suggests that the concentration of the endocannabinoid anandamide is regulated by cellular fatty acid amide hydrolase (FAAH). Therefore, we examined the rat ovary for the presence of CB1 and CB2 receptors and FAAH. The CB1 receptor was present in the ovarian surface epithelium (OSE), the granulosa cells of antral follicles, and the luteal cells of functional corpus luteum (CL). The granulosa cells of small preantral follicles, however, did not express the CB1 receptor. Western analysis also demonstrated the presence of a CB1 receptor. In both preantral and antral follicles, the CB2 receptor was detected only in the oocytes. In the functional CL, the CB2 receptor was detected in the luteal cells. FAAH was codistributed with CB2 receptor in both oocytes and luteal cells. FAAH was also present in the OSE, subepithelial cords of the tunica albuginea (TA) below the OSE, and in cells adjacent to developing preantral follicles. Western analysis also demonstrated the presence of FAAH in oocytes of both preantral and antral follicles. Our observations provide potential explanation for the effects of THC on steroidogenesis in the rat ovary observed by earlier investigators and a role for FAAH in the regulation of ovarian anandamide. Anat Rec 293:1425,1432, 2010. © 2010 Wiley-Liss, Inc. [source] Foraging ecology of howler monkeys in a cacao (Theobroma cacao) plantation in Comalcalco, MexicoAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2006David Muñoz Abstract Recent evidence indicates that primate populations may persist in neotropical fragmented landscapes by using arboreal agroecosystems, which may provide temporary habitats, increased areas of vegetation, and connectivity, among other benefits. However, limited data are available on how primates are able to sustain themselves in such manmade habitats. We report the results of a 9-month-long investigation of the feeding ecology of a troop of howler monkeys (n=24) that have lived for the past 25 years in a 12-ha cacao plantation in the lowlands of Tabasco, Mexico. A vegetation census indicated the presence of 630 trees (,20 cm diameter at breast height (DBH)) of 32 shade species in the plantation. The howlers used 16 plant species (13 of which were trees) as sources of leaves, fruits, and flowers. Five shade tree species (Ficus cotinifolia, Pithecellobium saman, Gliricidia sepium, F. obtusifolia, and Ficus sp.) accounted for slightly over 80% of the total feeding time and 78% of the total number trees (n=139) used by the howlers, and were consistently used by the howlers from month to month. The howlers spent an average of 51% of their monthly feeding time exploiting young leaves, 29% exploiting mature fruit, and 20% exploiting flowers and other plant items. Monthly consumption of young leaves varied from 23% to 67%, and monthly consumption of ripe fruit varied from 12% to 64%. Differences in the protein-to-fiber ratio of young vs. mature leaves influenced diet selection by the monkeys. The howlers used 8.3 ha of the plantation area, and on average traveled 388 m per day in each month. The howlers preferred tree species whose contribution to the total tree biomass and density was above average for the shade-tree population in the plantation. Given the right conditions of management and protection, shaded arboreal plantations in fragmented landscapes can sustain segments of howler monkey populations for many decades. Am. J. Primatol. 68:127,142, 2006. © 2006 Wiley-Liss, Inc. [source] Tracking Diabetes: New York City's A1C RegistryTHE MILBANK QUARTERLY, Issue 3 2009SHADI CHAMANY Context: In December 2005, in characterizing diabetes as an epidemic, the New York City Board of Health mandated the laboratory reporting of hemoglobin A1C laboratory test results. This mandate established the United States' first population-based registry to track the level of blood sugar control in people with diabetes. But mandatory A1C reporting has provoked debate regarding the role of public health agencies in the control of noncommunicable diseases and, more specifically, both privacy and the doctor-patient relationship. Methods: This article reviews the rationale for adopting the rule requiring the reporting of A1C test results, experience with its implementation, and criticisms raised in the context of the history of public health practice. Findings: For many decades, public health agencies have used identifiable information collected through mandatory laboratory reporting to monitor the population's health and develop programs for the control of communicable and noncommunicable diseases. The registry program sends quarterly patient rosters stratified by A1C level to more than one thousand medical providers, and it also sends letters, on the provider's letterhead whenever possible, to patients at risk of diabetes complications (A1C level >9 percent), advising medical follow-up. The activities of the registry program are similar to those of programs for other reportable conditions and constitute a joint effort between a governmental public health agency and medical providers to improve patients' health outcomes. Conclusions: Mandatory reporting has proven successful in helping combat other major epidemics. New York City's A1C Registry activities combine both traditional and novel public health approaches to reduce the burden of an epidemic chronic disease, diabetes. Despite criticism that mandatory reporting compromises individuals' right to privacy without clear benefit, the early feedback has been positive and suggests that the benefits will outweigh the potential harms. Further evaluation will provide additional information that other local health jurisdictions may use in designing their strategies to address chronic disease. [source] A new fast stratospheric ozone chemistry scheme in an intermediate general-circulation model.THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 610 2005I: Description, evaluation Abstract Simulation of future climate-composition changes requires simulations of coupled dynamical-radiative-chemical models of many decades in length. Yet, to assure the generality of the simulation's results against uncertainties in emissions, unforced year-to-year variability and dependence on initial conditions, it is necessary to repeat them a significant number of times. The computational cost of such an exercise is still too large when using complex three-dimensional coupled models. We introduce in this paper a computationally efficient chemical scheme, the FAst STratospheric Ozone Chemistry (FASTOC) scheme, which has advantages over many existing fast methods, as it does not rely on relaxation to assumed conditions, does not rely on tuning parameters, and does not rely on linearization approximations. The scheme is nevertheless three orders of magnitude faster than a stiff kinetic equations solver. Part I of the paper gives a detailed description of the FASTOC model and some performance evaluations when incorporated in a general-circulation model (GCM). In Part II, the FASTOC model, coupled to a GCM, is specifically applied to study the impact of climate,chemistry interactions on stratospheric ozone in the middle of the twenty-first century. Copyright © 2005 Royal Meteorological Society [source] Hypertonic saline in critical care: a review of the literature and guidelines for use in hypotensive states and raised intracranial pressure,ANAESTHESIA, Issue 9 2009G. F. Strandvik Summary Hypertonic saline has been in clinical use for many decades. Its osmotic and volume-expanding properties make it theoretically useful for a number of indications in critical care. This literature review evaluates the use of hypertonic saline in critical care. The putative mechanism of action is presented, followed by a narrative review of its clinical usefulness in critical care. The review was conducted using the Scottish Intercollegiate Guidelines Network method for the review of cohort studies, randomised-controlled trials and meta-analyses. The review focuses specifically on blood pressure restoration and outcome benefit in both haemorrhagic and non-haemorrhagic shock, and the management of raised intracranial pressure. Issues of clinical improvement and outcome benefit are addressed. Hypertonic saline solutions are effective for blood pressure restoration in haemorrhagic, but not other, types of shock. There is no survival benefit with the use of hypertonic saline solutions in shock. Hypertonic saline solutions are effective at reducing intracranial pressure in conditions causing acute intracranial hypertension. There is no survival or outcome benefit with the use of hypertonic saline solutions for raised intracranial pressure. Recommendations for clinical use and future directions of clinical research are presented. [source] Front and Back Covers, Volume 24, Number 3.ANTHROPOLOGY TODAY, Issue 3 2008June 200 Front cover and back cover caption, volume 24 issue 3 Front cover Front cover: Front cover In this issue of ANTHROPOLOGY TODAY, Adrian Peace takes a critical look at the way in which neo-evolutionary theories and anthropological concepts are brought together in an award-winning campaign to sell more meat in Australia (his article is debated by four respondents on pp 23,25). Among others adopting a critical perspective, the animal rights movement was outraged at claims made about red meat as a ,natural', ,healthy' and ,essential' part of the average Australian diet. Just as a prominent film star was recruited to the ,Red Meat , Feel Good' campaign, the hugely popular Missy Higgins was deployed to front the response from the animal rights movement. The youthful and fresh-faced Australian singer-songwriter, cuddling the vulnerable white piglet, iconically represents an informed, intelligent and humane vegetarian approach to the future in the relationship between human and non-human animals. Higgins here makes a striking plea for ,enlightenment'. Enlightenment of a different kind is offered by the poster reprinted on the back cover, where an Indian transvestite celebrates the joy of a minority gender identity. Although the rights of both human minorities and non-human animals may be ,universal', they must be rendered in culturally specific terms in order to be politically effective. Back cover Back cover: modern enlightenment in ancient sacred sites ,Be enlightened!' In 2006 ,Shelly Innocence' launched a new phone service in Bodhgaya, Bihar, offering customers the opportunity to receive personal text messages of EnlightenmentÔ on their mobile phones. Large billboards with images of this virtual transgendered guru were erected outside the main temple to advertise the service. Not only is Bodhgaya a site of inspiration for millions of Buddhists around the world, but the seat of enlightenment has also come to mean very different things as this cosmopolitan pilgrimage town goes global. For many decades the state of Bihar, where Bodhgaya is located, has been one of the least attractive destinations for pilgrims, tourists and anthropologists because of its notorious reputation as one of the most impoverished and ,lawless' states in the country. However in recent years the Mahabodhi Temple complex in Bodhgaya has become the object of global attention as a UNESCO World Heritage site, setting in motion a series of initiatives to encourage tourism and city development plans. As a result of new conservation policies and demands on the built environment, the World Heritage designation has become invested with a diverse set of claims and meanings by various stakeholders and religious communities. As a site of dense historical, religious and political significance, Bodhgaya today is a unique locus where spiritual and digital worlds collide in the shade of the bodhi tree. [source] | ||||||||||||||||||||||||||||||||||||||||