New Index (new + index)

Distribution by Scientific Domains

Selected Abstracts

Elongation Index as a New Index Determining the Severity of Left Ventricular Systolic Dysfunction and Mitral Regurgitation in Patients with Congestive Heart Failure

Mehmet Yokusoglu M.D.
The shape of the left ventricle is an important echocardiographic feature of left ventricular dysfunction. Progression of the mitral regurgitation and consequent left ventricular remodeling is unpredictable in heart failure. Elongation index is an index of left ventricular sphericity. The surface area of the elongated ventricle is larger than that of a spherical one. The objective of this study was to assess the relation between elongation index and the degree of mitral regurgitation along with noninvasive indices of left ventricular function. Thirty-two patients (21 male, 11 female, mean age: 57 ± 6 yrs) with congestive heart failure and mitral regurgitation were included. Patients were stratified into three groups according to vena contracta width as having mild (n = 11), moderate (n = 11) and severe mitral regurgitation (n = 10). The elongation index (EI) was considered as equal to {[(left ventricular internal area-measured) , (theoretical area of the sphere with measured left ventricular volume)]/(theoretical area of the sphere with measured left ventricular volume)}. Ejection fractions by the modified Simpson rule, dP/dt and sphericity index (SI) were also recorded. The relationship between (EI), ejection fraction, dP/dt and SI reached modest statistical significance (p < 0.05). When the EI and SI were compared, the correlation was also significant (p < 0.01). The areas under the receiver operator curve of EI and SI for discriminating dP/dt < 1000 mm Hg/s were 0.833 and 0.733, respectively. In conclusion, the elongation, which defines the shape of the left ventricle, might be related to the systolic function of the left ventricle and the degree of the mitral regurgitation. Further studies are needed to demonstrate its use in other clinical entities. [source]

Is the originality of a species measurable?

Sandrine Pavoine
Abstract In this paper, we introduce the concept of ,originality of a species within a set' in order to indicate the average rarity of all the features belonging to this species. Using a phylogenetic tree of 70 species of New World terrestrial Carnivora, we suggest measuring the originality by a probability distribution. This maximizes the expected number of features shared by two species randomly drawn from the set. By using this new index, we take account of branch lengths whereas current indices of originality focus on tree topology. As a supplement to Nee and May's optimizing algorithm, we find that originality must be one of the criteria used in conservation planning. [source]

Combining information from different sources to estimate a common effect and use of multiple measurements for ecological assessment

C. R. Rao
A statistical analysis for combining information from different sources to estimate an unknown parameter is outlined. A new index is then proposed as a measure of the quality of the site. Copyright © 2004 John Wiley & Sons, Ltd. [source]

A new index of habitat alteration and a comparison of approaches to predict stream habitat conditions

Summary 1. Stream habitat quality assessment complements biological assessment by providing a mechanism for ruling out habitat degradation as a potential stressor and provides reference targets for the physical aspects of stream restoration projects. This study analysed five approaches for predicting habitat conditions based on discriminant function, linear regressions, ordination and nearest neighbour analyses. 2. Quantitative physical and chemical habitat and riparian conditions in minimally-impacted streams in New Hampshire were estimated using United States Environmental Protection Agency's Environmental Monitoring and Assessment Program protocols. Catchment-scale descriptors were used to predict segment-scale stream channel and riparian habitat, and the accuracy and precision of the different modelling approaches were compared. 3. A new assessment index comparing and summarizing the degree of correspondence between predicted and observed habitat based on Euclidean distance between the standardized habitat factors is described. Higher index scores (i.e. greater Euclidean distance) would suggest a greater deviation in habitat between observed conditions and expected reference conditions. As in most biotic indices, the range in index scores in reference sites would constitute a situation equivalent to reference conditions. This new index avoids the erroneous prediction of multiple, mutually exclusive habitat conditions that have confounded previous habitat assessment approaches. 4. Separate linear regression models for each habitat descriptor yielded the most accurate and precise prediction of reference conditions, with a coefficient of variation (CV) between predictions and observations for all reference sites of 0.269. However, for a unified implementation in regions where a classification-based approach has already been taken for biological assessment, a discriminant analysis approach, that predicted membership in biotic communities and compared the mean habitat features in the biotic communities with the observed habitat features, was similar in prediction accuracy and precision (CV = 0.293). 5. The best model had an error of 27% of the mean index value for the reference sites, indicating substantial room for improvement. Additional catchment characteristics not readily available for this analysis, such as average rainfall or winter snow-pack, surficial geological characteristics or past land-use history, may improve the precision of the predicted habitat features in the reference streams. Land-use history in New Hampshire and regional environmental impacts have greatly impacted stream habitat conditions even in streams considered minimally-impacted today; thus as regional environmental impacts change and riparian forests mature, reference habitat conditions should be re-evaluated. [source]

Alleviation of the adverse effect of cooking on sorghum protein digestibility through fermentation in traditional African porridges

Janet Taylor
Cooking sorghum is well known to reduce its protein digestibility. In southern Africa fermented sorghum porridges are commonly consumed. Knowledge is lacking as to how their preparation affects sorghum protein digestibility. Five sorghum varieties of varied origin were fermented using traditional semi-solid state fermentation. In vitro protein digestibility and a new index, in vitro insoluble protein digestibility, were measured. Both increased during fermentation, generally within the first day, coinciding with a strong decrease in pH. The increase in insoluble protein digestibility suggests fermentation causes structural changes in the sorghum storage proteins (prolamins and glutelins), making them more accessible to pepsin attack. Wet cooking during porridge-making greatly reduced protein digestibility. Combining fermentation with cooking, either fermenting then cooking or cooking then fermenting, significantly improved protein digestibility over wet cooking alone. Thus natural fermentation, as applied in traditional African porridge preparation is an effective method of improving the protein digestibility of cooked sorghum. [source]

Novel parameter for the diagnosis of distal middle cerebral artery stenosis with transcranial Doppler sonography

Suk-Won Ahn MD
Abstract Purpose Transcranial Doppler sonography (TCD) is commonly used for the diagnosis of middle cerebral artery (MCA) stenosis. However, TCD indices to predict distal MCA (M2) stenosis have not yet been established. We compared TCD and magnetic resonance angiography (MRA) to validate a new index for the diagnosis of M2 stenosis. Methods Consecutive patients who underwent TCD and MRA were included. Based on MRA, M2 stenosis was defined as >50% narrowing beyond the bifurcation area. TCD index of the M2/M1 ratio was defined as the ratio between the mean flow velocity (MFV) obtained at a depth of 30,44 mm (M2) and a depth of 45,65 mm (M1). Sensitivity and specificity of the M2/M1 ratio were calculated from the receiver operating characteristic curve. The diagnostic yield of elevated MFV (>80 cm/s) and asymmetry index of >30% for M2 stenosis were also investigated. Results Among the consecutive patients, 105 with M2 stenosis were compared with 123 without MCA stenosis. The M2/M1 ratio was significantly higher in the M2 stenosis group (1.10 versus 0.86, p < 0.001). Sensitivity and specificity for M2 stenosis were most satisfying when the M2/M1 ratio of 0.97 was adopted as the cutoff value. Diagnostic yield of the M2/M1 ratio was better than MFV or asymmetry index. Conclusions The M2/M1 ratio may be a highly specific parameter for assessing M2 stenosis with TCD. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:420,425, 2010 [source]

Measuring beta-diversity from taxonomic similarity

Giovanni Bacaro
Abstract Question: The utility of beta (,-) diversity measures that incorporate information about the degree of taxonomic (dis)similarity between species plots is becoming increasingly recognized. In this framework, the question for this study is: can we define an ecologically meaningful index of ,-diversity that, besides indicating simple species turnover, is able to account for taxonomic similarity amongst species in plots? Methods: First, the properties of existing measures of taxonomic similarity measures are briefly reviewed. Next, a new measure of plot-to-plot taxonomic similarity is presented that is based on the maximal common subgraph of two taxonomic trees. The proposed measure is computed from species presences and absences and include information about the degree of higher-level taxonomic similarity between species plots. The performance of the proposed measure with respect to existing coefficients of taxonomic similarity and the coefficient of Jaccard is discussed using a small data set of heath plant communities. Finally, a method to quantify ,-diversity from taxonomic dissimilarities is discussed. Results: The proposed measure of taxonomic ,-diversity incorporates not only species richness, but also information about the degree of higher-order taxonomic structure between species plots. In this view, it comes closer to a modern notion of biological diversity than more traditional measures of ,-di-versity. From regression analysis between the new coefficient and existing measures of taxonomic similarity it is shown that there is an evident nonlinearity between the coefficients. This nonlinearity demonstrates that the new coefficient measures similarity in a conceptually different way from previous indices. Also, in good agreement with the findings of previous authors, the regression between the new index and the Jaccard coefficient of similarity shows that more than 80% of the variance of the former is explained by the community structure at the species level, while only the residual variance is explained by differences in the higher-order taxonomic structure of the species plots. This means that a genuine taxonomic approach to the quantification of plot-to-plot similarity is only needed if we are interested in the residual system's variation that is related to the higher-order taxonomic structure of a pair of species plots. [source]

The Mediterranean intercalibration exercise on soft-bottom benthic invertebrates with special emphasis on the Italian situation

MARINE ECOLOGY, Issue 4 2009
Anna Occhipinti Ambrogi
Abstract The intercalibration exercise is an important step in the building process of the surface water ecological quality assessment, which is required by the Water Framework Directive (WFD). Its aim is to apply the water quality classification in a uniform manner to all the Member States belonging to the same eco-region. Cyprus, France, Greece, Italy, Slovenia and Spain participated in the soft-bottom benthic invertebrate subgroup for the Mediterranean coastal region. The methodologies proposed by Member States were applied and tested; the results were compared and harmonized to establish agreed and comparable boundaries for the benthic invertebrate ecological status classes. The national methods used in the intercalibration process were: for Cyprus and Greece, the Bentix Index; for Slovenia, a combination of AZTI Marine Biotic Index (AMBI), richness and diversity with the use of factor and discriminant analysis (Multimetric AMBI); for Spain, a new index, named MEDOCC, which is an adaptation of the AMBI index to the Western Mediterranean area. Italy and France tested different methods, none of which have been officially adopted. Final class boundary values for the different official classification systems were obtained and compared. Besides describing methods and results obtained by the different countries, the Italian situation is examined in more detail. All the above methods have been applied to Italian data, but the results were not conclusive. Major causes for concern are related to insufficient sites and data, to the lack of real non-impacted reference sites, and to the difficulties in validating the ecological status classification in sites not showing a pollution gradient. [source]

A new algorithm to estimate aircraft icing in the HIRLAM model

Bernt Olofsson
A new index to estimate aircraft icing in clouds from operational meteorological models has been developed by Swedish meteorologists. Although rather simple it takes into account, directly or indirectly, all the principal meteorological variables for icing. The index has been evaluated during three winter seasons and is now operational in the Swedish HIRLAM model. A graphical representation of the index is presented. Copyright © 2003 Royal Meteorological Society [source]

The SAURON project , VI.

Line strength maps of 48 elliptical, lenticular galaxies
ABSTRACT We present absorption line strength maps of 48 representative elliptical and lenticular galaxies obtained as part of a survey of nearby galaxies using our custom-built integral-field spectrograph, SAURON, operating on the William Herschel Telescope. Using high-quality spectra, spatially binned to a constant signal-to-noise ratio, we measure four key age, metallicity and abundance ratio sensitive indices from the Lick/IDS system over a two-dimensional field extending up to approximately one effective radius. A discussion of calibrations and offsets is given, along with a description of error estimation and nebular emission correction. We modify the classical Fe5270 index to define a new index, Fe5270S, which maximizes the useable spatial coverage of SAURON. Maps of H,, Fe5015, Mg b and Fe5270S are presented for each galaxy. We use the maps to compute average line strengths integrated over circular apertures of one-eighth effective radius, and compare the resulting relations of index versus velocity dispersion with previous long-slit work. The metal line strength maps show generally negative gradients with increasing radius roughly consistent with the morphology of the light profiles. Remarkable deviations from this general trend exist, particularly the Mg b isoindex contours appear to be flatter than the isophotes of the surface brightness for about 40 per cent of our galaxies without significant dust features. Generally, these galaxies exhibit significant rotation. We infer from this that the fast-rotating component features a higher metallicity and/or an increased Mg/Fe ratio as compared to the galaxy as a whole. The H, maps are typically flat or show a mild positive outwards radial gradient, while a few galaxies show strong central peaks and/or elevated overall H, strength likely connected to recent star formation activity. For the most prominent post-starburst galaxies, even the metal line strength maps show a reversed gradient. [source]

Transparency, Political Polarization, and Political Budget Cycles in OECD Countries

James E. Alt
We investigate the effects of fiscal transparency and political polarization on the prevalence of electoral cycles in fiscal balance. While some recent political economy literature on electoral cycles identifies such cycles mainly in weak and recent democracies, in contrast we show, conditioning on a new index of institutional fiscal transparency, that electoral cycles in fiscal balance are a feature of many advanced industrialized economies. Using a sample of 19 OECD countries in the 1990s, we identify a persistent pattern of electoral cycles in low(er) transparency countries, while no such cycles can be observed in high(er) transparency countries. Furthermore, we find, in accordance with recent theory, that electoral cycles are larger in politically more polarized countries. [source]

Measuring Ethnic Fractionalization in Africa

Daniel N. Posner
In most studies of the impact of ethnic diversity on economic growth, diversity is hypothesized to affect growth through its effect on macroeconomic policies. This article shows that most measures of ethnic diversity (including the commonly used ELF measure) are inappropriate for testing this hypothesis. This is because they are constructed from enumerations of ethnic groups that include all of the ethnographically distinct groups in a country irrespective of whether or not they engage in the political competition whose effects on macroeconomic policymaking are being tested. I present a new index of ethnic fractionalization based on an accounting of politically relevant ethnic groups in 42 African countries. I employ this measure (called PREG, for Politically Relevant Ethnic Groups) to replicate Easterly and Levine's influential article on Africa's "growth tragedy." I find that PREG does a much better job of accounting for the policy-mediated effects of ethnic diversity on economic growth in Africa than does ELF. [source]

Heart Rate Variability Fraction,A New Reportable Measure of 24-Hour R-R Interval Variation

Maciej Sosnowski M.D.
Background: The scatterplot of R-R intervals has several unique features. Its numerical evaluation may produce a new useful index of global heart rate variability (HRV) from Holter recordings. Methods: Two-hundred and ten middle-aged healthy subjects were enrolled in this study. The study was repeated the next day in 165 subjects. Each subject had a 24-hour ECG recording taken. Preprocessed data were transferred into a personal computer and the standard HRV time-domain indices: standard deviation of total normal R-R intervals (SDNN), standard deviation of averaged means of normal R-R intervals over 5-minute periods (SDANN), triangular index (TI), and pNN50 were determined. The scatterplot area (0.2,1.8 second) was divided into 256 boxes, each of 0.1-second interval, and the number of paired R-R intervals was counted. The heart rate variability fraction (HRVF) was calculated as the two highest counts divided by the number of total beats differing from the consecutive beat by <50 ms. The HRVF was obtained by subtracting this fraction from 1, and converting the result to a percentage. Results: The normal value of the HRVF was 52.7 ± 8.6%. The 2,98% range calculated from the normal probability plot was 35.1,70.3%. The HRVF varied significantly with gender (female 48.7 ± 8.4% vs male 53.6 ± 8.6%, P = 0.002). The HRVF correlated with RRI (r = 0.525) and showed a similar or better relationship with SDNN (0.851), SDANN (0.653), and TI (0.845) than did the standard HRV measures with each other. Bland-Altman plot showed a good day-by-day reproducibility of the HRVF, with the intraclass correlation coefficient of 0.839 and a low relative standard error difference (1.8%). Conclusion: We introduced a new index of HRV, which is easy for computation, robust, reproducible, easy to understand, and may overcome the limitations that belong to the standard HRV measures. This index, named HRV fraction, by combining magnitude, distribution, and heart-rate influences, might become a clinically useful index of global HRV. [source]

Evaluation of floristic diversity in urban areas as a basis for habitat management

Audrey Muratet
Kerguélen (2003). Abstract Questions: How can floristic diversity be evaluated in conser-vation plans to identify sites of highest interest for biodiversity? What are the mechanisms influencing the distribution of species in human-dominated environments? What are the best criteria to identify sites where active urban management is most likely to enhance floristic diversity? Location: The Hauts-de-Seine district bordering Paris, France. Methods: We described the floristic diversity in one of the most urbanized French districts through the inventory of ca. 1000 sites located in 23 habitats. We built a new index of floristic interest (IFI), integrating information on richness, indigeneity, typicality and rarity of species, to identify sites and habitats of highest interest for conservation. Finally, we explored the relationship between site IFI and land use patterns (LUP). Results: We observed a total of 626 vascular plant species. Habitats with highest IFI were typically situated in seminatural environments or environments with moderate human impact. We also showed that neighbouring (urban) structures had a significant influence on the floristic interest of sites: for example, the presence of collective dwellings around a site had a strong negative impact on IFI. Conclusions: Our approach can be used to optimize management in urban zones; we illustrate such possibilities by defining a ,Site Potential Value', which was then compared with the observed IFI, to identify areas (e.g. river banks) where better management could improve the district's biodiversity. [source]

The LUNDEX, a new index of drug efficacy in clinical practice: Results of a five-year observational study of treatment with infliximab and etanercept among rheumatoid arthritis patients in southern Sweden

Lars Erik Kristensen
Objective To describe the use of the LUNDEX, a new index for comparing the long-term efficacy and tolerability of biologic therapies in rheumatoid arthritis (RA) patients treated in clinical practice. Methods Patients (n = 949) with active RA that had not responded to at least 2 disease-modifying antirheumatic drugs (DMARDs) including methotrexate, in whom biologic therapy was being initiated, were included in a structured clinical followup protocol. The protocol included collection of data on diagnosis, disease duration, previous and ongoing DMARD treatment, and dates on which biologic treatment was started and terminated. In addition, data on efficacy measures used for calculating validated response criteria, i.e., the European League Against Rheumatism and American College of Rheumatology response criteria, were collected at fixed time points. Data were prospectively registered from March 1999 through January 2004. The LUNDEX, a new index combining the proportion of patients fulfilling a selected response criteria set with the proportion of patients adhering to a particular therapy, was designed to compare the efficacy of the different therapies. Results Etanercept had higher overall LUNDEX values compared with infliximab, mostly because of a lower rate of adherence to therapy with infliximab. The relationship between the drugs was consistent irrespective of the response criteria used. Conclusion The LUNDEX is a valuable tool for evaluating drug efficacy in observational studies. It has the advantage of integrating clinical response as well as adherence to therapy in a composite value. Moreover, the LUNDEX has a practical and potentially universal application independent of diagnosis and response criteria. [source]

Experimental Study of a New Method for Early Detection of Vascular Access Stenoses: Pulse Pressure Analysis at Hemodialysis Needle

Koen Van Canneyt
Abstract Hemodialysis vascular access (VA) stenosis remains a frequent complication. However, early detection is challenging and costly. The aim of this in vitro study was to assess a new detection method based on pulse pressure analysis at the hemodialysis needle. A silicon model of a radiocephalic arteriovenous fistula was built in a mock loop. Pressure profiles were measured at the arterial hemodialysis needle and in the proximal feeding artery. Stenoses (50 and 25% diameter reduction) were created proximal to the anastomosis (proximal artery) and distal to the arterial needle (distal vein and proximal vein). The pulse pressure (PP) at the needle was divided by the PP at the feeding artery to obtain a dimensionless ratio, %PP. Experiments were conducted at different blood flow (500,1200 mL/min) and heart rates (60,90 beats/min) to test this new index over a wide range of hemodynamic conditions. In the control model (no stenosis), %PP was 20.26 ± 4.55. A proximal artery 50% stenosis significantly decreased %PP to 7.69 ± 2.08 (P < 0.0001), while the presence of 50% stenosis in the distal (36.20 ± 2.12) and proximal (32.38 ± 2.17) vein led to significantly higher values of %PP (P < 0.0001). For stenosis of 25% diameter reduction in the proximal artery, the %PP decreased to 15.45 ± 2.13 (P = 0.0022) and the %PP increased with a 25% stenosis in the distal vein to 26.71 ± 3.01 (P = 0.0003) and in the proximal vein to 26.53 ± 2.67 (P = 0.0004). This in vitro study shows that the analysis of the PP at the dialysis needle is useful for early detection and localization of hemodialysis VA stenosis, independent of heart rate and flow level. [source]

A new index of access to primary care services in rural areas

Matthew R. McGrail
Abstract Objective: To outline a new index of access to primary care services in rural areas that has been specifically designed to overcome weaknesses of using existing geographical classifications. Methods: Access was measured by four key dimensions of availability, proximity, health needs and mobility. Population data were obtained through the national census and primary care service data were obtained through the Medical Directory of Australia. All data were calculated at the smallest feasible geographical unit (collection districts). The index of access was measured using a modified two-step floating catchment area (2SFCA) method, which incorporates two necessary additional spatial functions (distance-decay and capping) and two additional non-spatial dimensions (health needs and mobility). Results: An improved index of access, specifically designed to better capture access to primary care in rural areas, is achieved. These improvements come from: 1) incorporation of actual health service data in the index; 2) methodological improvements to existing access measures, which enable both proximity to be differentiated within catchments and the use of varying catchment sizes; and 3) improved sensitivity to small-area variations. Conclusion: Despite their recognised weaknesses, the Australian government uses broad geographical classifications as proxy measures of access to underpin significant rural health funding programs. This new index of access could provide a more equitable means for resource allocation. Implications: Significant government funding, aimed at improving health service access inequities in rural areas, could be better targeted by underpinning programs with our improved access measure. [source]

Area under the Free-Response ROC Curve (FROC) and a Related Summary Index

BIOMETRICS, Issue 1 2009
Andriy I. Bandos
Summary Free-response assessment of diagnostic systems continues to gain acceptance in areas related to the detection, localization, and classification of one or more "abnormalities" within a subject. A free-response receiver operating characteristic (FROC) curve is a tool for characterizing the performance of a free-response system at all decision thresholds simultaneously. Although the importance of a single index summarizing the entire curve over all decision thresholds is well recognized in ROC analysis (e.g., area under the ROC curve), currently there is no widely accepted summary of a system being evaluated under the FROC paradigm. In this article, we propose a new index of the free-response performance at all decision thresholds simultaneously, and develop a nonparametric method for its analysis. Algebraically, the proposed summary index is the area under the empirical FROC curve penalized for the number of erroneous marks, rewarded for the fraction of detected abnormalities, and adjusted for the effect of the target size (or "acceptance radius"). Geometrically, the proposed index can be interpreted as a measure of average performance superiority over an artificial "guessing" free-response process and it represents an analogy to the area between the ROC curve and the "guessing" or diagonal line. We derive the ideal bootstrap estimator of the variance, which can be used for a resampling-free construction of asymptotic bootstrap confidence intervals and for sample size estimation using standard expressions. The proposed procedure is free from any parametric assumptions and does not require an assumption of independence of observations within a subject. We provide an example with a dataset sampled from a diagnostic imaging study and conduct simulations that demonstrate the appropriateness of the developed procedure for the considered sample sizes and ranges of parameters. [source]

A new index for rating aesthetics of implant-supported single crowns and adjacent soft tissues , the Implant Crown Aesthetic Index

A pilot study on validation of a new index
Abstract Objectives: The important item of aesthetics is rarely included in evaluation studies. The aim of this study was to develop and validate an index for rating aesthetics of implant-supported single crowns and adjacent soft tissues. Material and methods: Nine items were selected, which have an influence on the aesthetic result. The items are based on the anatomic form, colour and surface characteristics of the crown and on the anatomic form, colour and surface characteristics of the peri-implant soft tissues. Two oral-maxillofacial surgeons and two prosthodontists rated 24 implant-supported single-tooth restorations and adjacent soft tissues on a form with the nine items of the rating index. The rating was carried out twice by each of the examiners. Weighted Cohen's , was calculated to express the intra- and interobserver agreement. Results: Intraobserver results indicated that the agreement between the first and second rating of both the prosthodontists was good (both 0.7) and that the agreement of the oral-maxillofacial surgeons was moderate (0.49 and 0.56). The best interobserver agreement was found between the two prosthodontists (0.61, good agreement). Conclusions: The Implant Crown Aesthetic Index is an objective tool in rating aesthetics of implant-supported single crowns and adjacent soft tissues. The rating is best be carried out by one prosthodontist to have the highest reliability. Résumé L'aspect important qu'est l'esthétique est rarement inclus dans les études d'évaluation. Le but de cette étude était de développer et de valider un index pour évaluer l'esthétique d'implants avec une couronne unique et les tissus mous adjacents. Neuf points ayant une influence sur le résultat esthétique ont été sélectionnés. Ces points sont basés sur une forme anatomique, des caractéristiques de surface et de couleur de la couronne et de la forme anatomique, la couleur et les caractéristiques de surface des tissus mous paroïmplantaires. Deux chirurgiens maxillo-faciaux et deux spécialistes en prothèse ont évalué 24 restaurations de dents uniques sur implants et leurs tissus mous adjacents dans un formulaire avec les neuf points de l'indice d'évaluation. L'évaluation a été effectuée deux fois par chacun des examinateurs. Le kappa de Cohen a été calculé pour exprimer l'accord intra- et inter-observateurs. Les résultats intra-observateurs ont indiqué que l'accord entre la première et la deuxième évaluation étaient bonnes pour les spécialistes en prothèse (les deux 0,70) et l'accord pour les chirurgiens était moyen (0,49 et 0,56). Le meilleur accord inter-observateurs était trouvé entre les deux spécialistes de prothèse (0,61, bon accord). L'indice d'esthétique de la couronne sur implant est un outil objectif dans l'évaluation de l'esthétique des couronnes uniques sur implant et les tissus mous adjacents. L'évaluation est mieux effectuée par un spécialiste en prothèse pour obtenir la plus haute précision. Zusammenfassung Ziele: Der wichtige Faktor Aesthetik wird kaum in Untersuchungen miteinbezogen. Das Ziel dieser Studie war, einen Index zur Wertung der Aesthetik von implantatgetragenen Einzelkronen und der angrenzenden Weichgewebe zu entwickeln und zu werten. Material und Methoden: Neun Punkte wurden ausgewählt, welche einen Einfluss auf das Ästhetische Resultat haben. Die Punkte basierten auf der anatomischen Form, Farb- und Oberflächencharakteristiken der Krone und auf der anatomischen Form, Farb- und Formcharakteristiken der peri-implantären Weichgewebe. Zwei Kieferchirurgen und zwei Prothetikspezialisten bewerteten 24 implantatgetragene Einzelkronen und die angrenzenden Weichgewebe auf einem Formular mit 9 Punkten des Wertungsindex. Die Bewertung wurde von jedem Untersucher zweimal durchgeführt. Es wurden gewichtete Cohen`s Kappa berechnet, um die Uebereinstimmung innerhalb der Untersucher und zwischen den verschiednen Untersuchern auszudrücken. Resutate: Die Resultate innerhalb der Untersucher zeigten, dass die Uebereinstimmung zwischen der ersten und der zweiten Bewertung bei beiden Prothetikern gut war (beide 0.7) und dass die Uebereinstimmung bei den Kieferchirurgen mässig ausfiel (0.49 und 0.56). Die beste Uebereinstimmung zwischen zwei verschiedenen Untersuchern wurde zwischen den beiden Prothetikern gefunden (0.61, gut Uebereinstimmung). Schlussfolgerung: Der Implantat Kronen Aesthetik Index stellt ein objektives Werkzeug zur Bewertung der Aesthetik von implantatgetragenen Einzelkronen und der angrenzenden Weichgewebe dar. Die Bewertung wird am besten durch einen Prothetikspezialisten durchgeführt, um die höchste Zuverlässigkeit zu erhalten. Resumen Objetivos: El punto importante de la estética raramente se incluye en estudios de evaluación. La intención del presente estudio fue desarrollar y validar un índice para valorar la estética de las coronas unitarias implantosoportadas y los tejidos blandos adyacentes. Material y métodos: Se seleccionaron nueve puntos, que tienen influencia en el resultado estético. Los puntos se basan en la forma anatómica, color y características de la superficie de la corona y en la forma anatómica, color y características de la superficie de los tejidos blandos periimplantarios. Dos cirujanos maxilofaciales y dos prostodoncistas valoraron 24 restauraciones unitarias implantosoportadas y los tejidos blandos adyacentes en un formulario con nueve puntos del índice de valoración. La valoración se llevó a cabo dos veces por cada examinador. Se calculó el weighted kappa de Cohen para expresar la concordancia intra- e interobservador. Resultados: Los resultados intraobservador indicaron que el acuerdo entre la primera y la segunda valoración de ambos prostodoncistas fue buena (ambos 0.70) y que el acuerdo de los cirujanos maxilofaciales fue moderada (0.49 y 0.56). El mejor acuerdo interobservador se encontró entre los dos prostodoncistas (0.61, buen acuerdo). Conclusión: El Índice de Estética de Coronas de Implantes es una herramienta objetiva en la valoración de la estética de las coronas unitarias implantosoportadas y los tejidos blandos adyacentes. La valoración se llevó mejor a cabo por un prostodoncista que tuvo la mayor fiabilidad. [source]

United Kingdom and Ireland precipitation variability and the North Atlantic sea-level pressure field

Sarah J. Murphy
Abstract The relationship between UK and Ireland (UK&I) precipitation variability and the North Atlantic sea-level pressure (SLP) field is examined. Strong positive correlations between the North Atlantic Oscillation (NAO) and precipitation in the northwest of the UK&I, particularly in winter, are confirmed but correlations are insignificant at the 0.05 level in the southeast during all months. This paper identifies new patterns of SLP associated with precipitation variability both for regions and months where precipitation variability is not strongly linked with the NAO and for patterns that appear to be more closely related to UK&I precipitation than the NAO. Two indices of monthly UK&I precipitation variability are calculated using empirical orthogonal functions (EOFs) of monthly UK&I precipitation anomalies. EOF1 represents precipitation variability for the UK&I as a whole and EOF2 the variability in the north,south precipitation gradient across the UK&I. Correlations between both these monthly EOF derived precipitation indices and SLP show a north,south (sub-tropical/mid-latitude) dipole, which is particularly strong in winter. These correlation patterns are then used to construct new SLP indices, which necessarily relate more closely to UK&I precipitation. The first index resembles the East Atlantic pattern from September to April. The second may be thought of as an alternative index of the NAO, such that it is optimized with respect to precipitation variability and is located northeast of those centres of action most commonly used to calculate the NAO index. Stepwise linear regression models, incorporating the two new indices and the original NAOI, suggest that over 25% of UK&I precipitation variability this century (1900,1994) in each month can be explained by a simple index representation of the North Atlantic SLP field. This rises to over 40% of variance explained in nearly all regions of the UK&I. Copyright © 2001 Royal Meteorological Society [source]

One class classifiers for process monitoring illustrated by the application to online HPLC of a continuous process

Sila Kittiwachana
Abstract In process monitoring, a representative out-of-control class of samples cannot be generated. Here, it is assumed that it is possible to obtain a representative subset of samples from a single ,in-control class' and one class classifiers namely Q and D statistics (respectively the residual distance to the disjoint PC model and the Mahalanobis distance to the centre of the QDA model in the projected PC space), as well as support vector domain description (SVDD) are applied to disjoint PC models of the normal operating conditions (NOC) region, to categorise whether the process is in-control or out-of-control. To define the NOC region, the cumulative relative standard deviation (CRSD) and a test of multivariate normality are described and used as joint criteria. These calculations were based on the application of window principal components analysis (WPCA) which can be used to define a NOC region. The D and Q statistics and SVDD models were calculated for the NOC region and percentage predictive ability (%PA), percentage model stability (%MS) and percentage correctly classified (%CC) obtained to determine the quality of models from 100 training/test set splits. Q, D and SVDD control charts were obtained, and 90% confidence limits set up based on multivariate normality (D and Q) or SVDD D value (which does not require assumptions of normality). We introduce a method for finding an optimal radial basis function for the SVDD model and two new indices of percentage classification index (%CI) and percentage predictive index (%PI) for non-NOC samples are also defined. The methods in this paper are exemplified by a continuous process studied over 105.11,h using online HPLC. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Measuring the components of competition along productivity gradients

Summary 1Controversy surrounds the measurement of competition intensity. Moreover, when biomass varies systematically along productivity and other environmental gradients, common indices of competitive outcome mask important ecological interactions. 2This study presents two indices derived from how neighbours interact with target plants. The first, relative crowding, increases directly with the abundance of neighbours present and decreases inversely with the potential size and vigour of the target plant itself. The second, interaction strength, is the integral of suppression of the target by neighbours over the range of neighbour abundance. Relative crowding and interaction strength are derived independently, but when multiplied produce the commonly used relative competitive index, showing the biological underpinnings of the relative competition index in terms of crowding and strength of interaction. Since the new indices of relative crowding and interaction strength explicitly account for the amount of neighbour biomass, they serve as a valid method to track the effects of changing habitat conditions on the components of competition. 3The new indices are applied to three published data sets. In each case, relative crowding increased with standing crop. In one case competition was reported as unchanged along a productivity gradient, whereas the new indices show that relative crowding and interaction strength both had significant patterns, but their effects were counteracting. These results do not fit current theories of competition. Further empirical studies are needed to see if competition theory needs revision. 4Separating the mechanisms of competition into relative crowding and strength of interaction reveals previously hidden patterns that help bring to light underlying processes of competition along productivity gradients. [source]

Two New Statistics to Detect Answer Copying

Leonardo S. Sotaridona
Two new indices to detect answer copying on a multiple-choice test,S1 and S2,were proposed. The S1 index is similar to the K index (Holland, 1996) and the K2 index (Sotaridona & Meijer, 2002) but the distribution of the number of matching incorrect answers of the source and the copier is modeled by the Poisson distribution instead of the binomial distribution to improve the detection rate of K and K2. The S2 index was proposed to overcome a limitation of the K and K2 index, namely, their insensitiveness to correct answers copying. The S2 index incorporates the matching correct answers in addition to the matching incorrect answers. A simulation study was conducted to investigate the usefulness of S1 and S2 for 40- and 80-item tests, 100 and 500 sample sizes, and 10%, 20%, 30%, and 40% answer copying. The Type I errors and detection rates of S1 and S2 were compared with those of the K2 and the , copying index (Wollack, 1997). Results showed that all four indices were able to maintain their Type I errors, with S1 and K2 being slightly conservative compared to S2 and ,. Furthermore, S1 had higher detection rates than K2. The S2 index showed a significant improvement in detection rate compared to K and K2. [source]

Assessment of a capability index sensitive to skewness

P. C. Nahar
Abstract For many quality characteristics, such as circularity, cylindricity, straightness and flatness, positive skewness in the inspection data is the norm, and, in fact, is desirable. Summarizing the process performance using such data in conjunction with capability indices has recently received a considerable amount of attention, with new indices being proposed and compared for usefulness and accuracy. This paper is intended to contribute to this growing discussion, and to add a unique focus. In particular, this investigation concentrates on one form of a neoclassical index, the Cs index, originally proposed to be sensitive to skewness and to decrease in value as the skewness increased in the underlying distribution of the data. In other words, ,skewness is badness'. Looking at this index from an altered perspective, the possibility that this index could serve a useful purpose in summarizing process performance for such non-normal processes by merely changing its interpretation or slightly changing its form is considered. Hence, actual data from circularity measurements are used to identify a relevant group of distributions, and then the accuracy of Cs is investigated along with its modified version for this group of distributions. In particular, this investigation includes several Rayleigh and gamma distributions for various sample sizes and reports on the bias of the proposed estimators. These findings indicate that such a modified index has some useful attributes in reflecting process performance, with respect to the percentage of non-conformance and the accuracy for relatively large samples. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Habitat indices for rivers: derivation and applications

Ian P. Vaughan
Abstract 1.River Habitat Survey (RHS) is the standard riverine hydromorphology survey in the UK and modified versions have been adopted in several other European Countries. It aims to broadly characterize physical features over 500,m reaches, but in so doing records more than 100 variables, often making interpretation and data analysis challenging. In such instances, synoptic treatment of the data, creating simple indices such as Habitat Modification and Habitat Quality Assessment scores, can prove beneficial. 2.The derivation of seven new indices is described, summarizing nearly half of the variables used by RHS and providing a quantitative overall summary of river reaches. 3.Derived using an objective analysis of the RHS database (cf expert judgement), one index describes bedrock/boulder channels, two indices describe bank and riparian vegetation and a further two describe aspects of sediment transport and deposition. Two distinct types of modification,,,bank reinforcement and channel re-sectioning,,,are also quantified. 4.Rigorous testing indicates that the indices are reliable across the complete range of conditions and countries in the UK. 5.The new indices are readily interpreted and while providing a simple overview of a river reach, they are objective and quantitative, lending themselves to a range of management and research applications. They have already been used successfully in quantifying riverine bird habitats and this, along with other applications, is discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source]