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Terms modified by Data Base Selected AbstractsThe national cancer data base report on squamous cell carcinoma of the base of tongue,,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2004Weining Zhen MD Abstract Background. This study provides the largest contemporary overview of presentation, care, and outcome for base of tongue squamous cell carcinoma (SCC). Methods. We extracted 16,188 cases from the National Cancer Data Base (NCDB). Chi-square analyses were performed on selected cross-tabulations. Observed and disease-specific survival were used to analyze outcome. Results. Three-quarters had advanced-stage (III,IV) disease. Radiation therapy alone (24.5%) and combined with surgery (26.9%) were the most common treatments. Five-year observed and disease-specific survival rates were 27.8% and 40.3%, respectively. Poorer survival was significantly associated with older age, low income, and advanced-stage disease. For early-stage disease, surgery with or without irradiation had higher survival than irradiation alone. For advanced-stage disease, surgery with irradiation had the highest survival. Conclusions. Survival rates were low for base of tongue SCC, with most deaths occurring within the first 2 years. Income, stage, and age were significant prognostic factors. In this nonrandomized series, surgery with radiation therapy offered patients with advanced-stage disease the best survival. © 2004 Wiley Periodicals, Inc. Head Neck 26: 660,674, 2004 [source] Mutations in human monoamine-related neurotransmitter pathway genes,HUMAN MUTATION, Issue 7 2008Jan Haavik Abstract Biosynthesis and metabolism of serotonin and catecholamines involve at least eight individual enzymes that are mainly expressed in tissues derived from the neuroectoderm, e.g., the central nervous system (CNS), pineal gland, adrenal medulla, enterochromaffin tissue, sympathetic nerves, and ganglia. Some of the enzymes appear to have additional biological functions and are also expressed in the heart and various other internal organs. The biosynthetic enzymes are tyrosine hydroxylase (TH), tryptophan hydroxylases type 1 and 2 (TPH1, TPH2), aromatic amino acid decarboxylase (AADC), dopamine beta-hydroxylase (D,H), and phenylethanolamine N -methyltransferase (PNMT), and the specific catabolic enzymes are monoamine oxidase A (MAO-A) and catechol O -methyltransferase (COMT). For the TH, DDC, DBH, and MAOA genes, many single nucleotide polymorphisms (SNPs) with unknown function, and small but increasing numbers of cases with autosomal recessive mutations have been recognized. For the remaining genes (TPH1, TPH2, PNMT, and COMT) several different genetic markers have been suggested to be associated with regulation of mood, pain perception, and aggression, as well as psychiatric disturbances such as schizophrenia, depression, suicidality, and attention deficit/hyperactivity disorder. The genetic markers may either have a functional role of their own, or be closely linked to other unknown functional variants. In the future, molecular testing may become important for the diagnosis of such conditions. Here we present an overview on mutations and polymorphisms in the group of genes encoding monoamine neurotransmitter metabolizing enzymes. At the same time we propose a unified nomenclature for the nucleic acid aberrations in these genes. New variations or details on mutations will be updated in the Pediatric Neurotransmitter Disorder Data Base (PNDDB) database (www.bioPKU.org). Hum Mutat 29(7), 891,902, 2008. © 2008 Wiley-Liss, Inc. [source] Intellectual disability in Western AustraliaJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2000C Bower Objective: To investigate the prevalence of intellectual disability in Western Australia (WA), its causes, prevention, and trends over time. Methodology: Data from an administrative database of intellectual disability in WA were used to report on the trends in intellectual disability in childhood. Results: The prevalence of intellectual disability was 8.3 per 1000 live births in 1980,90. For half the cases, there was no known cause for the intellectual disability. Down syndrome accounted for 14 to 15% of all cases. Since the introduction of newborn screening, no WA-born child participating in the screening program has been diagnosed with intellectual disability as a result of either phenylketonuria or congenital hypothyroidism. The rate of autism spectrum disorders rose from three to six per 10 000 in the 1980,83 WA birth cohort to 10,13 per 10 000 for the 1989,92 cohort. Conclusions: Recent linkage of this administrative database to the WA Maternal and Child Health Research Data Base provides a unique opportunity for more detailed investigation of intellectual disability and its risk factors in a large, well-ascertained population of children. [source] Abstracts of QSAR-related Publications: Data Base, Virtual ScreeningMOLECULAR INFORMATICS, Issue 4 2009Article first published online: 3 APR 200 First page of article [source] Abstracts of QSAR-related Publications: Data Base, Virtual ScreeningMOLECULAR INFORMATICS, Issue 2 2009Article first published online: 10 FEB 200 First page of article [source] Abstracts of QSAR-related Publications: Data Base, Virtual ScreeningMOLECULAR INFORMATICS, Issue 9 2008Article first published online: 17 SEP 200 First page of article [source] Abstracts of QSAR-related Publications: Data Base, Virtual ScreeningMOLECULAR INFORMATICS, Issue 6 2007Article first published online: 5 JUN 200 No abstract is available for this article. [source] Laryngeal Cancer in the United States: Changes in Demographics, Patterns of Care, and SurvivalTHE LARYNGOSCOPE, Issue S111 2006FACS, Henry T. Hoffman MD Abstract Background: Survival has decreased among patients with laryngeal cancer during the past 2 decades in the United States. During this same period, there has been an increase in the nonsurgical treatment of laryngeal cancer. Objective: The objectives of this study were to identify trends in the demographics, management, and outcome of laryngeal cancer in the United States and to analyze factors contributing to the decreased survival. Study Design: The authors conducted a retrospective, longitudinal study of laryngeal cancer cases. Methods: Review of the National Cancer Data Base (NCDB) revealed 158,426 cases of laryngeal squamous cell carcinoma (excluding verrucous carcinoma) diagnosed between the years 1985 and 2001. Analysis of these case records addressed demographics, management, and survival for cases grouped according to stage, site, and specific TNM classifications. Results: This review of data from the NCDB analysis confirms the previously identified trend toward decreasing survival among patients with laryngeal cancer from the mid-1980s to mid-1990s. Patterns of initial management across this same period indicated an increase in the use of chemoradiation with a decrease in the use of surgery despite an increase in the use of endoscopic resection. The most notable decline in the 5-year relative survival between the 1985 to 1990 period and the 1994 to 1996 period occurred among advanced-stage glottic cancer, early-stage supraglottic cancers, and supraglottic cancers classified as T3N0M0. Initial treatment of T3N0M0 laryngeal cancer (all sites) in the 1994 to 1996 period resulted in poor 5-year relative survival for those receiving either chemoradiation (59.2%) or irradiation alone (42.7%) when compared with that of patients after surgery with irradiation (65.2%) and surgery alone (63.3%). In contrast, identical 5-year relative survival (65.6%) rates were observed during this same period for the subset of T3N0M0 glottic cancers initially treated with either chemoradiation or surgery with irradiation. Conclusions: The decreased survival recorded for patients with laryngeal cancer in the mid-1990s may be related to changes in patterns of management. Future studies are warranted to further evaluate these associations. [source] Two-Micron All-Sky Survey J01542930+0053266: a new eclipsing M dwarf binary systemMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008A. C. Becker ABSTRACT We report on Two-Micron All-Sky Survey (2MASS) J01542930+0053266, a faint eclipsing system composed of two M dwarfs. The variability of this system was originally discovered during a pilot study of the 2MASS Calibration Point Source Working Data base. Additional photometry from the Sloan Digital Sky Survey yields an eight-passband light curve from which we derive an orbital period of 2.639 0157 ± 0.000 0016 d. Spectroscopic followup confirms our photometric classification of the system, which is likely composed of M0 and M1 dwarfs. Radial velocity measurements allow us to derive the masses (M1= 0.66 ± 0.03 M,; M2= 0.62 ± 0.03 M,) and radii (R1= 0.64 ± 0.08 R,; R2= 0.61 ± 0.09 R,) of the components, which are consistent with empirical mass,radius relationships for low-mass stars in binary systems. We perform Monte Carlo simulations of the light curves which allow us to uncover complicated degeneracies between the system parameters. Both stars show evidence of H, emission, something not common in early-type M dwarfs. This suggests that binarity may influence the magnetic activity properties of low-mass stars; activity in the binary may persist long after the dynamos in their isolated counterparts have decayed, yielding a new potential foreground of flaring activity for next generation variability surveys. [source] Species richness of helminth parasites in Mexican amphibians and reptilesDIVERSITY AND DISTRIBUTIONS, Issue 4 2002Gerardo Pérez-Ponce de León Abstract. Amphibians and reptiles represent an important group of vertebrates in Mexico; on a global scale 10% of the biodiversity of these groups is found in the country, attaining extraordinarily high levels of endemism (60.7% and 53.7%, respectively). However, fewer than 20% of the known species of amphibians and reptiles in Mexico have been surveyed for helminths, so the inventory is far from complete. We assembled a data base that includes a total of 1246 records (entries) of which 460 correspond to helminths in amphibians and 786 to helminths in reptiles. In total, only 41 species of amphibians (14% of those occurring in Mexico) and only 118 species of reptiles (17% of those occurring in Mexico) have been studied for helminth parasites. From amphibians, 119 species of helminths belonging to 60 genera have been recorded, while 239 species of helminths representing 113 genera have been described from Mexican reptiles. One feature of the distribution of helminths of Mexican amphibians and reptiles is its asymmetry, as seen in representation of helminth groups, host groups and geographical range. However, such statistical asymmetry might be an artefact of sampling effort. Based on our data, we estimate that if all the herpetofauna of Mexico could be studied in the following years, approximately 827 additional species of helminths from amphibians and approximately 1403 from reptiles would be described. [source] Is the crisis problem growing more severe?ECONOMIC POLICY, Issue 32 2001Michael Bordo The crisis problem is one of the dominant macroeconomic features of our age. Its prominence suggests questions like the following: Are crises growing more frequent? Are they becoming more disruptive? Are economies taking longer to recover? These are fundamentally historical questions, which can be answered only by comparing the present with the past. To this end, this paper develops and analyses a data base spanning 120 years of financial history. We find that crisis frequency since 1973 has been double that of the Bretton Woods and classical gold standard periods and is rivalled only by the crisis-ridden 1920s and 1930s. History thus confirms that there is something different and disturbing about our age. However, there is little evidence that crises have grown longer or output losses have become larger. Crises may have grown more frequent, in other words, but they have not obviously grown more severe. Our explanation for the growing frequency and chronic costs of crises focuses on the combination of capital mobility and the financial safety net, including the implicit insurance against exchange risk provided by an ex ante credible policy of pegging the exchange rate, which encourages banks and corporations to accumulate excessive foreign currency exposures. We also provide policy recommendations for restoring stability and growth. , Michael Bordo, Barry Eichengreen, Daniela Klingebiel and Maria Soledad Martinez-Peria [source] Does Higher Education Matter?EUROPEAN JOURNAL OF EDUCATION, Issue 1 2007Lessons from a Comparative Graduate Survey Renewed public interest in the relationships between higher education and the world of work and a deficient data base contributed to the decision to undertake a major comparative study on graduate employment and work. In the framework of the CHEERS study, supported by the European Commission's TSER programme, some 40,000 graduates of the academic year 1994/95 from 11 European countries and Japan were surveyed about four years later. The study paid attention to the transition to employment, the employment situation during the first four years after graduation, the links between competences acquired and work tasks, as well as the professional impact of values and orientations. Altogether, the findings indicate major North-South differences of graduate employment in Europe, but less clear findings as far as work assignments and retrospective views of higher education are concerned. They show on average a more favourable employment and work situation than the public debates suggest, few signs of European convergence, for example with respect to preference for generalists or professionals, and a high weight of intrinsic values. [source] The European Court, National Judges, and Legal Integration: A Researcher's Guide to the Data Set on Preliminary References in EC Law, 1958--98EUROPEAN LAW JOURNAL, Issue 2 2000Alec Stone Sweet We hope to stimulate more systematic research on all areas of legal integration by making available for free and open use a comprehensive data base on preliminary references in EC law. The Data Set, which has been under construction since 1996, is now online at various websites. The data are not publicly accessible elsewhere. In this article, we provide a brief summary of the data base and its potential uses. We begin by introducing the main features of the Data Set. We then discuss some of the dynamics of legal integration in light of our analyses of the data. [source] Below-ground carbon flux and partitioning: global patterns and response to temperatureFUNCTIONAL ECOLOGY, Issue 6 2008C. M. Litton Summary 1The fraction of gross primary production (GPP) that is total below-ground carbon flux (TBCF) and the fraction of TBCF that is below-ground net primary production (BNPP) represent globally significant C fluxes that are fundamental in regulating ecosystem C balance. However, global estimates of the partitioning of GPP to TBCF and of TBCF to BNPP, as well as the absolute size of these fluxes, remain highly uncertain. 2Efforts to model below-ground processes are hindered by methodological difficulties for estimating below-ground C cycling, the complexity of below-ground interactions, and an incomplete understanding of the response of GPP, TBCF and BNPP to climate change. Due to a paucity of available data, many terrestrial ecosystem models and ecosystem-level studies of whole stand C use efficiency rely on assumptions that: (i) C allocation patterns across large geographic, climatic and taxonomic scales are fixed; and (ii) c. 50% of TBCF is BNPP. 3Here, we examine available information on GPP, TBCF, BNPP, TBCF : GPP and BNPP : TBCF from a diverse global data base of forest ecosystems to understand patterns in below-ground C flux and partitioning, and their response to mean annual temperature (MAT). 4MAT and mean annual precipitation (MAP) covaried strongly across the global forest data base (37 mm increase in MAP for every 1 °C increase in MAT). In all analyses, however, MAT was the most important variable explaining observed patterns in below-ground C processes. 5GPP, TBCF and BNPP all increased linearly across the global scale range of MAT. TBCF : GPP increased significantly with MAT for temperate and tropical ecosystems (> 5 °C), but variability was high across the data set. BNPP : TBCF varied from 0·26 to 0·53 across the entire MAT gradient (,5 to 30 °C), with a much narrower range of 0·42 to 0·53 for temperate and tropical ecosystems (5 to 30 °C). 6Variability in the data sets was moderate and clear exceptions to the general patterns exist that likely relate to other factors important for determining below-ground C flux and partitioning, in particular water availability and nutrient supply. Still, our results highlight global patterns in below-ground C flux and partitioning in forests in response to MAT that in part confirm previously held assumptions. [source] Redox Processes and Water Quality of Selected Principal Aquifer SystemsGROUND WATER, Issue 2 2008P.B. McMahon Reduction/oxidation (redox) conditions in 15 principal aquifer (PA) systems of the United States, and their impact on several water quality issues, were assessed from a large data base collected by the National Water-Quality Assessment Program of the USGS. The logic of these assessments was based on the observed ecological succession of electron acceptors such as dissolved oxygen, nitrate, and sulfate and threshold concentrations of these substrates needed to support active microbial metabolism. Similarly, the utilization of solid-phase electron acceptors such as Mn(IV) and Fe(III) is indicated by the production of dissolved manganese and iron. An internally consistent set of threshold concentration criteria was developed and applied to a large data set of 1692 water samples from the PAs to assess ambient redox conditions. The indicated redox conditions then were related to the occurrence of selected natural (arsenic) and anthropogenic (nitrate and volatile organic compounds) contaminants in ground water. For the natural and anthropogenic contaminants assessed in this study, considering redox conditions as defined by this framework of redox indicator species and threshold concentrations explained many water quality trends observed at a regional scale. An important finding of this study was that samples indicating mixed redox processes provide information on redox heterogeneity that is useful for assessing common water quality issues. Given the interpretive power of the redox framework and given that it is relatively inexpensive and easy to measure the chemical parameters included in the framework, those parameters should be included in routine water quality monitoring programs whenever possible. [source] Antidepressants in clinical practice: limitations of assessment methods and drug responseHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 1 2001Sidney H Kennedy Abstract There is a recognized gap between knowledge derived from ,efficacy' data , based on usually brief randomized controlled trials and findings in natural practice ,effectiveness' studies. In considering the limitations of current antidepressants in clinical practice, we have selected three clinically important issues to examine in a natural practice data base that has been in existence for several years. These relate to: (1) Diagnostic heterogeneity and potential advances using functional brain imaging; (2) Variability of outcome measures during treatment and (3) Time to response and prediction of outcome. Copyright © 2001 John Wiley & Sons, Ltd. [source] Improving the evidence base for international comparative researchINTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 193-194 2008Ekkehard Mochmann Industrial societies today produce abundant data fed by the statistical system, social research, market research and administrative data. This is increasingly complemented by processing data produced from sources like commercial transactions. Looking at societies in an international comparative perspective, however, we find many incoherent patterns or even white spots on the globe. Nevertheless, we can observe encouraging progress over past decades. The pioneers of the data movement worked towards an international network of data infrastructures that were conceived as building blocks in a system of social observation. Gaps in the statistical data base had to be filled by sample surveys from social research. This resulted in a network of social science data services to preserve and process the data collected to make them available for secondary analysis, and systematic efforts to continuously collect data comparative by design and to make them available as a public good to the scientific community at large. Increasingly we can observe a rapprochement that has been taking place between social policy and social research since the turn of the millennium. Facing the challenges of globalisation we cannot however, overlook the fact that in spite of all progress, social science data have been collected predominantly with a national perspective, are not well integrated and , even if they are technically and legally accessible , do not easily lend themselves to comparison between nations or periods of time. International data programmes may well profit from the methodological standardisation and harmonisation of measurements as well as from technical progress towards the easier access to and interoperability of data bases. These processes will profit much, if growing efforts to agree on data policies and funding perspectives for international and transcontinental cooperation succeed. [source] A new land-cover map of Africa for the year 2000JOURNAL OF BIOGEOGRAPHY, Issue 6 2004Philippe Mayaux Abstract Aim, In the framework of the Global Land Cover 2000 (GLC 2000), a land-cover map of Africa has been produced at a spatial resolution of 1 km using data from four sensors on-board four different Earth observing satellites. Location, The map documents the location and distribution of major vegetation types and non-vegetated land surface formations for the entire African continent plus Madagascar and the other surrounding islands. Methods, The bulk of these data were acquired on a daily basis throughout the year 2000 by the VEGETATION sensor on-board the SPOT-4 satellite. The map of vegetation cover has been produced based upon the spectral response and the temporal profile of the vegetation cover. Digital image processing and geographical information systems techniques were employed, together with local knowledge, high resolution imagery and expert consultation, to compile a cartographic map product. Radar data and thermal sensors were also used for specific land-cover classes. Results, A total of 27 land cover categories are documented, which has more thematic classes than previously published land cover maps of Africa contain. Systematic comparison with existing land cover data and 30-m resolution imagery from Landsat are presented, and the map is also compared with other pan-continental land cover maps. The map and digital data base are freely available for non-commercial uses from http://www.gvm.jrc.it/tem/africa/products.htm Main conclusions, The map improves our state of knowledge of the land-cover of Africa and presents the most spatially detailed view yet published at this scale. This first version of the map should provide an important input for regional stratification and planning purposes for natural resources, biodiversity and climate studies. Résumé Objet, Dans le cadre du projet Global Land Cover 2000 (GLC 2000), une carte d'Afrique d'occupation du sol a été produite à la résolution spatiale de 1 km à partir de données satellitales de 4 capteurs différents. Localisation, La carte représente la distribution des principaux types de végétation et des surfaces non-végétales du continent africain plus Madagascar et les autres îles voisines du continent. Méthodes, La plupart des données fut acquise durant l'année 2000 par le capteur VEGETATION, embarquéà bord du satellite SPOT-4. La réponse spectrale et le profil temporel des formations végétales ont permis la production de la carte d'occupation du sol. Des techniques de traitement d'image et de systèmes d'information géographique ont été combinées à la consultation d'experts locaux et à l'utilisation de cartes nationales et de données à haute résolution spatiale. Des images radar et thermiques ont servi à cartographier des classes spécifiques. Résultats, Un total de 27 classes est cartographié, ce qui est plus que les précédentes cartes basées sur l'imagerie satellitale. Une comparaison systématique avec les cartes publiées et des images Landsat à 30 m est présentée. Les données sont libres d'accès pour un usage non-commercial à l'adresse http://www.gvm.jrc.it/tem/africa/products.htm Conclusion, Cette carte accroît notre connaissance de l'occupation du sol de l'Afrique et présente la vue la plus détaillée jamais publiée à cette échelle. La première version de la carte devrait fournir une base importante pour une stratification régionale et pour la planification d'études sur les ressources naturelles, la biodiversité et le climat. [source] The uncertain blitzkrieg of Pleistocene megafaunaJOURNAL OF BIOGEOGRAPHY, Issue 4 2004Barry W. Brook Abstract We investigated, using meta-analysis of empirical data and population modelling, plausible scenarios for the cause of late Pleistocene global mammal extinctions. We also considered the rate at which these extinctions may have occurred, providing a test of the so-called ,blitzkrieg' hypothesis, which postulates a rapid, anthropogenically driven, extinction event. The empirical foundation for this work was a comprehensive data base of estimated body masses of mammals, comprising 198 extinct and 433 surviving species > 5 kg, which we compiled through an extensive literature search. We used mechanistic population modelling to simulate the role of human hunting efficiency, meat off-take, relative naivety of prey to invading humans, variation in reproductive fitness of prey and deterioration of habitat quality (due to either anthropogenic landscape burning or climate change), and explored the capacity of different modelling scenarios to recover the observed empirical relationship between body mass and extinction proneness. For the best-fitting scenarios, we calculated the rate at which the extinction event would have occurred. All of the modelling was based on sampling randomly from a plausible range of parameters (and their interactions), which affect human and animal population demographics. Our analyses of the empirical data base revealed that the relationship between body mass and extinction risk relationship increases continuously from small- to large-sized animals, with no clear ,megafaunal' threshold. A logistic ancova model incorporating body mass and geography (continent) explains 92% of the variation in the observed extinctions. Population modelling demonstrates that there were many plausible mechanistic scenarios capable of reproducing the empirical body mass,extinction risk relationship, such as specific targeting of large animals by humans, or various combinations of habitat change and opportunistic hunting. Yet, given the current imperfect knowledge base, it is equally impossible to use modelling to isolate definitively any single scenario to explain the observed extinctions. However, one universal prediction, which applied in all scenarios in which the empirical distribution was correctly predicted, was for the extinctions to be rapid following human arrival and for surviving fauna to be suppressed below their pre-,blitzkrieg' densities. In sum, human colonization in the late Pleistocene almost certainly triggered a ,blitzkrieg' of the ,megafauna', but the operational details remain elusive. [source] Conundrums in mixed woody,herbaceous plant systemsJOURNAL OF BIOGEOGRAPHY, Issue 11 2003Joanna I. House Abstract Aims To identify approaches to improve our understanding of, and predictive capability for, mixed tree,grass systems. Elucidation of the interactions, dynamics and determinants, and identification of robust generalizations that can be broadly applied to tree,grass systems would benefit ecological theory, modelling and land management. Methods A series of workshops brought together scientific expertise to review theory, data availability, modelling approaches and key questions. Location Ecosystems characterized by mixtures of herbaceous and woody plant life-forms, often termed ,savannas', range from open grasslands with few woody plants, to woodlands or forests with a grass layer. These ecosystems represent a substantial portion of the terrestrial biosphere, an important wildlife habitat, and a major resource for provision of livestock, fuel wood and other products. Results Although many concepts and principles developed for grassland and forest systems are relevant to these dual life-form communities, the novel, complex, nonlinear behaviour of mixed tree,grass systems cannot be accounted for by simply studying or modelling woody and herbaceous components independently. A more robust understanding requires addressing three fundamental conundrums: (1) The ,treeness' conundrum. What controls the relative abundance of woody and herbaceous plants for a given set of conditions at given site? (2) The coexistence conundrum. How do the life-forms interact with each other? Is a given woody,herbaceous ratio dynamically stable and persistent under a particular set of conditions? (3) The net primary productivity (NPP) conundrum. How does NPP of the woody vegetation, the herbaceous vegetation, and the total ecosystem (woody + herbaceous) change with changes in the tree,grass ratio? Tests of the theory and conceptual models of determinants of mixed woody,herbaceous systems have been largely site- or region-specific and have seldom been broadly or quantitatively evaluated. Cross-site syntheses based on data and modelling are required to address the conundrums and identify emerging patterns, yet, there are very few data sets for which either biomass or NPP have been quantified for both the woody and the herbaceous components of tree,grass systems. Furthermore, there are few cross-site comparisons spanning the diverse array of woody,herbaceous mixtures. Hence, initial synthesis studies should focus on compiling and standardizing a global data base which could be (1) explored to ascertain if robust generalizations and consistent patterns exist; and (2) used to evaluate the performance of savanna simulation models over a range of woody,herbaceous mixtures. Savanna structure and productivity are the result of complex and dynamic interactions between climate, soils and disturbances, notably fire and herbivory. Such factors are difficult to isolate or experimentally manipulate in order to evaluate their impacts at spatial and temporal scales appropriate for assessing ecosystem dynamics. These factors can, however, be evaluated with simulation models. Existing savanna models vary markedly with respect to their conceptual approach, their data requirements and the extent to which they incorporate mechanistic processes. Model intercomparisons can elucidate those approaches most suitable for various research questions and management applications. Conclusion Theoretical and conceptual advances could be achieved by considering a broad continuum of grass,shrub,tree combinations using data meta-analysis techniques and modelling. [source] O knowledge, where art thou?JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 6 2009Evidence, suspected appendicitis Abstract Background, Much effort goes into developing and publishing guidelines which physicians fail to implement. We feel that major discrepancies still exist between theory and reality and that the translational approach to this aspect of medical care has not yet established itself. We therefore decided to investigate in an exemplary audit how liberally inappropriate imaging is used in our emergency department (ED) to rule out acute appendicitis. Material and methods, Our electronic medical record ED database ,Qualicare' (http://www.qualidoc.ch) was searched using the ,appendicitis' sub data base. The frequency and accuracy of abdominal imaging was determined in patients with clinically suspected appendicitis on admission over a 5-year period at a university hospital emergency unit. Results, In total, 272 (41.2%) of the 577 patients were male and 305 (46.3%) were female. The attending physicians ordered abdominal X-rays in 133 patients, abdominal ultrasounds in 319, and abdominal computerized tomography (CT) scans in 93 patients. 125 patients underwent more than one imaging procedure. In all, 85/125 patients received a combination of X-rays, ultrasound and CT scanning! Discussion, Physicians are often insecure about indications for surgery and therefore order useless imaging procedures. The reliability of such procedures in excluding acute appendicitis is limited, which was confirmed by our results. Although evidence-based medicine guidelines exist, they are neglected for many reasons. Future academic efforts should therefore focus more on knowledge translation and the implementation of existing knowledge by heightening awareness, rather than on simply creating new guidelines. [source] Raman spectroscopic study of the phosphate mineral churchite-(Y) YPO4·2H2OJOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2010Ray L. Frost Abstract Raman spectroscopy has been used to study the rare-earth mineral churchite-(Y) of formula (Y,REE)(PO4) ·2H2O, where rare-earth element (REE) is a rare-earth element. The mineral contains yttrium and, depending on the locality, a range of rare-earth metals. The Raman spectra of two churchite-(Y) mineral samples from Jáchymov and Medv,dín in the Czech Republic were compared with the Raman spectra of churchite-(Y) downloaded from the RRUFF data base. The Raman spectra of churchite-(Y) are characterized by an intense sharp band at 975 cm,1 assigned to the ,1 (PO43,) symmetric stretching mode. A lower intensity band observed at around 1065 cm,1 is attributed to the ,3 (PO43,) antisymmetric stretching mode. The (PO43,) bending modes are observed at 497 cm,1 (,2) and 563 cm,1 (,4). Some small differences in the band positions between the four churchite-(Y) samples from four different localities were found. These differences may be ascribed to the different compositions of the churchite-(Y) minerals. Copyright © 2009 John Wiley & Sons, Ltd. [source] Factors associated with radiation exposure in patients with inflammatory bowel diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11-12 2009Z. LEVI Summary Background, Inflammatory bowel disease (IBD) patients undergo multiple radiological evaluations. Aim, To estimate total and abdominal radiation exposure from diagnostic X-ray investigations in IBD patients and the associated risk factors. Methods, Patients with Crohn's disease (CD) or ulcerative colitis (UC) treated in the IBD clinic were recruited. Clinical data were extracted from patient files and radiological data were obtained from the central HMO computer data base. Results, A total of 199 CD and 125 UC patients were included. The mean cumulative estimated doses (CED) for CD and UC were 21.1 ± 19.5 and 15.1 ± 20.4 millisieverts (mSv) respectively (P < 0.001). Twenty-three patients (7.1%) had an estimated CED of ,50 mSv. In multivariate analyses, predictors of increased CED were: surgery (OR 5.68, 95% CI: 2.73,11.8, P < 0.001), CD (OR 2.56, 95% CI: 1.29,5.07, P = 0.007), prednisone use (OR 2.0, 95% CI: 1.11,3.67, P = 0.02), first year of disease (OR 6.4, 95% CI: 1.3,32, P = 0.02) and age in the upper quartile (OR 3.26, 95% CI: 1.68,6.3, P = 0.001). Conclusions, Diagnosis of CD, IBD-related surgery, prednisone use, first year of diagnosis and age on the upper quartile are independent predictors of increased exposure in IBD patients. Alternative investigations which do not require radiation exposure should be considered for patients at risk for increased radiation exposure. [source] Orbital and physical parameters of eclipsing binaries from the All-Sky Automated Survey catalogue , I. A sample of systems with components' masses between 1 and 2 M,MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2009K. G. He, miniak ABSTRACT We derive the absolute physical and orbital parameters for a sample of 18 detached eclipsing binaries from the All-Sky Automated Survey (ASAS) data base based on the available photometry and our own radial velocity (RV) measurements. The RVs are computed using spectra we collected with the 3.9-m Anglo-Australian Telescope (AAT) and its University College London Echelle Spectrograph (UCLES), and the 1.9-m Radcliffe telescope and its Grating Instrument for Radiation Analysis with a Fibre-Fed Echelle (GIRAFFE) at the South African Astronomical Observatory (SAAO). In order to obtain as precise RVs as possible, most of the systems were observed with an iodine cell available at the AAT/UCLES and/or analysed using the two-dimensional cross-correlation technique (TODCOR). The RVs were measured with TODCOR using synthetic template spectra as references. However, for two objects we used our own approach to the tomographic disentangling of the binary spectra to provide observed template spectra for the RV measurements and to improve the RV precision even more. For one of these binaries, AI Phe, we were able to the obtain an orbital solution with an RV rms of 62 and 24 m s,1 for the primary and secondary, respectively. For this system, the precision in M sin3i is 0.08 per cent. For the analysis, we used the photometry available in the ASAS data base. We combined the RV and light curves using phoebe and jktebop codes to obtain the absolute physical parameters of the systems. Having precise RVs, we were able to reach ,0.2 per cent precision (or better) in masses in several cases but in radii, due to the limited precision of the ASAS photometry, we were able to reach a precision of only 1 per cent in one case and 3,5 per cent in a few more cases. For the majority of our objects, the orbital and physical analysis is presented for the first time. [source] Discovery of new nearby L and late-M dwarfs at low Galactic latitude from the DENIS data baseMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2008N. Phan-Bao ABSTRACT We report on new nearby L and late-M dwarfs (dphot, 30 pc) discovered in our search for nearby ultracool dwarfs (I,J, 3.0, later than M8.0) at low Galactic latitude (|b| < 15°) over 4800 deg2 in the Deep Near Infrared Survey of the Southern Sky (DENIS) data base. We used late-M (, M8.0), L and T dwarfs with accurate trigonometric parallaxes to calibrate the MJ versus I,J colour,luminosity relation. The resulting photometric distances have standard errors of ,15 per cent, which we used to select candidates dphot, 30 pc. We measured proper motions from multi-epoch images found in the public archives ALADIN, DSS, 2MASS and DENIS, with at least three distinct epochs and time baselines of 10,21 yr. We then used a maximum reduced proper motion cut-off to select 28 candidates as ultracool dwarfs (M8.0,L8.0) and to reject one as a distant red star. No T dwarf candidates were found in this search, which required an object to be detected in all three DENIS bands. Our low-resolution optical spectra confirmed that 26 were indeed ultracool dwarfs, with spectral types from M8.0 to L5.5. Two contaminants and one rejected by the maximum reduced proper motion cut-off were all reddened F,K main sequence stars. 20 of these 26 ultracool dwarfs are new nearby ultracool dwarf members, three L dwarfs within 15 pc with one L3.5 at only ,10 pc. We determine a stellar density of dwarfs pc,3 mag,1 over 11.1 ,MJ, 13.1 based on this sample of M8,L3.5 ultracool dwarfs. Our ultracool dwarf density value is in good agreement with the measurement by Cruz et al. of the ultracool dwarf density at high Galactic latitude. [source] Post-common-envelope binaries from SDSS , I. 101 white dwarf main-sequence binaries with multiple Sloan Digital Sky Survey spectroscopyMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007A. Rebassa-Mansergas ABSTRACT We present a detailed analysis of 101 white dwarf main-sequence binaries (WDMS) from the Sloan Digital Sky Survey (SDSS) for which multiple SDSS spectra are available. We detect significant radial velocity variations in 18 WDMS, identifying them as post-common-envelope binaries (PCEBs) or strong PCEB candidates. Strict upper limits to the orbital periods are calculated, ranging from 0.43 to 7880 d. Given the sparse temporal sampling and relatively low spectral resolution of the SDSS spectra, our results imply a PCEB fraction of ,15 per cent among the WDMS in the SDSS data base. Using a spectral decomposition/fitting technique we determined the white dwarf effective temperatures and surface gravities, masses and secondary star spectral types for all WDMS in our sample. Two independent distance estimates are obtained from the flux-scaling factors between the WDMS spectra, and the white dwarf models and main-sequence star templates, respectively. Approximately one-third of the systems in our sample show a significant discrepancy between the two distance estimates. In the majority of discrepant cases, the distance estimate based on the secondary star is too large. A possible explanation for this behaviour is that the secondary star spectral types that we determined from the SDSS spectra are systematically too early by one to two spectral classes. This behaviour could be explained by stellar activity, if covering a significant fraction of the star by cool dark spots will raise the temperature of the interspot regions. Finally, we discuss the selection effects of the WDMS sample provided by the SDSS project. [source] The UKIRT Infrared Deep Sky Survey (UKIDSS)MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007A. Lawrence ABSTRACT We describe the goals, design, implementation, and initial progress of the UKIRT Infrared Deep Sky Survey (UKIDSS), a seven-year sky survey which began in 2005 May. UKIDSS is being carried out using the UKIRT Wide Field Camera (WFCAM), which has the largest étendue of any infrared astronomical instrument to date. It is a portfolio of five survey components covering various combinations of the filter set ZYJHK and H2. The Large Area Survey, the Galactic Clusters Survey, and the Galactic Plane Survey cover approximately 7000 deg2 to a depth of K, 18; the Deep Extragalactic Survey covers 35 deg2 to K, 21, and the Ultra Deep Survey covers 0.77 deg2 to K, 23. Summed together UKIDSS is 12 times larger in effective volume than the 2MASS survey. The prime aim of UKIDSS is to provide a long-term astronomical legacy data base; the design is, however, driven by a series of specific goals , for example, to find the nearest and faintest substellar objects, to discover Population II brown dwarfs, if they exist, to determine the substellar mass function, to break the z= 7 quasar barrier; to determine the epoch of re-ionization, to measure the growth of structure from z= 3 to the present day, to determine the epoch of spheroid formation, and to map the Milky Way through the dust, to several kpc. The survey data are being uniformly processed. Images and catalogues are being made available through a fully queryable user interface , the WFCAM Science Archive (http://surveys.roe.ac.uk/wsa). The data are being released in stages. The data are immediately public to astronomers in all ESO member states, and available to the world after 18 months. Before the formal survey began, UKIRT and the UKIDSS consortia collaborated in obtaining and analysing a series of small science verification (SV) projects to complete the commissioning of the camera. We show some results from these SV projects in order to demonstrate the likely power of the eventual complete survey. Finally, using the data from the First Data Release, we assess how well UKIDSS is meeting its design targets so far. [source] Parent stars of extrasolar planets , VIII.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2007Chemical abundances for 18 elements in 31 stars ABSTRACT We present the results of detailed spectroscopic abundance analyses for 18 elements in 31 nearby stars with planets (SWPs). The resulting abundances are combined with other similar studies of nearby SWPs and compared to a sample of nearby stars without detected planets. We find some evidence for abundance differences between these two samples for Al, Si and Ti. Some of our results are in conflict with a recent study of SWPs in the SPOCS data base. We encourage continued study of the abundance patterns of SWPs to resolve these discrepancies. [source] Analysing the atolls: X-ray spectral transitions of accreting neutron starsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2007Jeanette Gladstone ABSTRACT We systematically analyse all the available X-ray spectra of disc accreting neutron stars (atolls and millisecond pulsars) from the RXTE data base. We show that while all these have similar spectral evolution as a function of mass accretion rate, there are also subtle differences. There are two different types of hard/soft transition, those where the spectrum softens at all energies, leading to a diagonal track on a colour,colour diagram, and those where only the higher energy spectrum softens, giving a vertical track. The luminosity at which the transition occurs is correlated with this spectral behaviour, with the vertical transition at L/LEdd, 0.02 while the diagonal one is at ,0.1. Superimposed on this is the well-known hysteresis effect, but we show that classic, large-scale hysteresis occurs only in the outbursting sources, indicating that its origin is in the dramatic rate of change of mass accretion rate during the disc instability. We show that the long-term mass accretion rate correlates with the transition behaviour, and speculate that this is due to the magnetic field being able to emerge from the neutron star surface for low average mass accretion rates. While this is not strong enough to collimate the flow except in the millisecond pulsars, its presence may affect the inner accretion flow by changing the properties of the jet. [source] Kinematic structure in the Galactic halo at the North Galactic Pole: RR Lyrae and blue horizontal branch stars show different kinematicsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007T. D. Kinman ABSTRACT Radial velocities and proper motions (derived from the GSC-II data base) are given for 38 RR Lyrae (RRL) stars and 79 blue horizontal branch (BHB) stars in a ,200 deg2 area around the North Galactic Pole (NGP). Both heliocentric (UVW) and galactocentric (VR, V,, Vz) space motions are derived for these stars using a homogeneous distance scale consistent with (m,M)0= 18.52 for the Large Magellanic Cloud (LMC). An analysis of the 26 RRL and 52 BHB stars whose height (Z) above the plane is less than 8 kpc shows that this halo sample is not homogeneous. Our BHB sample (like that of Sirko et al.) has a zero galactic rotation (V,) and roughly isotropic velocity dispersions. The RRL sample shows a definite retrograde rotation (V,=,95 ± 29 km s,1) and non-isotropic velocity dispersions. The combined BHB and RRL sample has a retrograde galactic rotation (V) that is similar to that found by Majewski for his sample of subdwarfs in Selected Area (SA) 57. The velocity dispersion of the RRL stars that have a positive W motion is significantly smaller than the dispersion of those ,streaming down' with a negative W. Also, the ratio of RRL to BHB stars is smaller for the sample that has positive W. Our halo sample occupies 10.4 kpc3 at a mean height of 5 kpc above the Galactic plane. In this volume, one component (rich in RRL stars) shows retrograde rotation and the streaming motion that we associate with the accretion process. The other component (traced by the BHB stars) shows essentially no rotation and less evidence of streaming. These two components have horizontal branch (HB) morphologies that suggest that they may be the field star equivalents of the young and old halo globular clusters, respectively. Clearly, it is quite desirable to use more than one tracer in any kinematic analysis of the halo. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||