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Residuals
Kinds of Residuals Terms modified by Residuals Selected AbstractsElectrochemical Determination of a Free Chlorine Residual Using Cathodic Potential-Step ChronocoulometryELECTROANALYSIS, Issue 8 2005Shin-ya Kishioka Abstract The cathodic reaction of chlorine residual (CR) combined with anodic pre-electrolysis enables the quantification of CR as a gaseous chlorine. Potential-step chronocoulometry was successfully applied to extend the CR detection range. [source] Transcatheter Closure of Congenital Ventricular Septal Defects: Experience with Various DevicesJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2003RAMESH ARORA D.M. Transcatheter closure of congenital ventricular septal defect (VSD) using various devices is gaining acceptance in selected cases of perimembranous and muscular defects, avoiding the inherent risks of cardiopulmonary bypass. The procedure was attempted in 137 patients having congenital defects using Rashkind Umbrella Device (RUD) in 29 patients, Amplatzer ventricular septal occluder (AVSO) in 107 patients, and Detachable Coil in one. All patients were selected using stringent criteria by detailed transthoracic echocardiography and/or transesophageal echocardiography. The location of VSD was perimembranous in 91 patients and was muscular trabecular in 46 patients. Seven patients had left ventricle (LV) to right atrium (RA) communication. Thirty-five patients with perimembranous and two with muscular VSD had aneurysm formation. The patients were 3 to 33 years old, and the diameter of VSD ranged from 3 to 12 mm. The pulmonary to systemic flow ratio was ,2:1 in 47 (34.3%) patients. The procedure was successful in 130 (94.8%) patients, with a success rate of 86.2% with RUD and 97.1% with AVSO. Residual shunt at 24 hours was seen in eight (32%) patients with RUD and in one patient (0.9%) with AVSO. Three (2.8%) developed transient bundle branch block, and two (1.9%) patients had complete heart block. New tricuspid stenosis and tricuspid regurgitation was observed in one patient each with AVSO. After immediate balloon dilatation, the mean pressure gradient across tricuspid valve decreased from 11 to 3 mmHg in the patient with tricuspid stenosis. On a follow-up of 1 to 66(mean 35.2 ± 10.7)months, the device was in position in all. None developed late conduction defect, aortic regurgitation, infective endocarditis, or hemolysis. At 9-month follow-up, the mean pressure gradient across the tricuspid valve was 3 mmHg in the patient with tricuspid stenosis. Complete occlusion of the shunt was achieved in 129 (99.2%) patients. One patient with RUD having persistent residual shunt underwent a second procedure with AVSO. Three out of 107 patients with AVSO had an unsuccessful procedure where the defect was perimembranous with a superior margin of defect less than 3 mm away from the aortic valve, and the specially designed perimembranous AVSO had to be retrieved because of hemodynamic compromise due to significant acute aortic regurgitation, whereas in all others, the defect was either ,3 mm away from the aortic valve or had aneurysm formation. All seven patients with LV to RA communication showed complete abolition of the shunt. Thus, in properly selected cases of perimembranous and muscular ventricular septal defects, the transcatheter closure is safe and efficacious using appropriate devices. The success rate is higher with AVSO compared with the previously used devices, as well as more successful for the muscular defects than those that are perimembranous in location. (J Interven Cardiol 2003;16:83,91) [source] A RAPID METHOD OF QUANTIFYING THE RESOLUTION LIMITS OF HEAT-FLOW ESTIMATES IN BASIN MODELSJOURNAL OF PETROLEUM GEOLOGY, Issue 2 2008A. Beha Deterministic forward models are commonly used to quantify the processes accompanying basin evolution. Here, we describe a workflow for the rapid calibration of palaeo heat-flow behaviour. The method determines the heat-flow history which best matches the observed data, such as vitrinite reflectance, which is used to indicate the thermal maturity of a sedimentary rock. A limiting factor in determining the heat-flow history is the ability of the algorithm used in the software for the maturity calculation to resolve information inherent in the measured data. Thermal maturation is controlled by the temperature gradient in the basin over time and is therefore greatly affected by maximum burial depth. Calibration, i.e. finding the thermal history model which best fits the observed data (e.g. vitrinite reflectance), can be a time-consuming exercise. To shorten this process, a simple pseudo-inverse model is used to convert the complex thermal behaviour obtained from a basin simulator into more simple behaviour, using a relatively simple equation. By comparing the calculated "simple" maturation trend with the observed data points using the suggested workflow, it becomes relatively straightforward to evaluate the range within which a best-fit model will be found. Reverse mapping from the simple model to the complex behaviour results in precise values for the heat-flow which can then be applied to the basin model. The goodness-of-fit between the modelled and observed data can be represented by the Mean Squared Residual (MSR) during the calibration process. This parameter shows the mean squared difference between all measured data and the respective predicted maturities. A minimum MSR value indicates the "best fit". Case studies are presented of two wells in the Horn Graben, Danish North Sea. In both wells calibrating the basin model using a constant heat-flow over time is not justified, and a more complex thermal history must be considered. The pseudo-inverse method was therefore applied iteratively to investigate more complex heat-flow histories. Neither in the observed maturity data nor in the recorded stratigraphy was there evidence for erosion which would have influenced the present-day thermal maturity pattern, and heat-flow and time were therefore the only variables investigated. The aim was to determine the simplest "best-fit" heat-flow history which could be resolved at the maximum resolution given by the measured maturity data. The conclusion was that basin models in which the predicted maturity of sedimentary rocks is calibrated solely against observed vitrinite reflectance data cannot provide information on the timing of anomalies in the heat-flow history. The pseudo inverse method, however, allowed the simplest heat-flow history that best fits the observed data to be found. [source] Transvenous Embolization of Small Patent Ductus Arteriosus with Single Detachable Coils in DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2001Matthias Schneider Transvenous embolization of small patent ductus arteriosus (PDA; , 4 mm) with a single detachable coil was attempted in 24 dogs (median age 5.7 months, range, 2.6,65.5 months; median body weight 5.5 kg, range, 1.5,30.0 kg). Angiographic imaging of the duct and pressure measurements were made before and after embolization. The minimal ductal diameter was 2.7 ± 0.7 mm. In all dogs, a single coil was employed regardless of residual shunting. Ten dogs (PDA minimal diameter range, 1.5-2.2 mm) received a 5-mm coil, and 14 dogs (PDA minimal diameter range, 2.9-3.6 mm) received a 8-mm coil. After coil embolization the angiographic shunt grade decreased significantly (n = 20, P < .001). Residual shunts were assessed by angiography 15 minutes after and by Doppler echocardiography 1,3 days and 3 months after the intervention. In the dogs treated with the 5-mm coils the residual shunt rate was low (0%, 10%, and 0% for angiography and Doppler echocardiography at 1,3 days and 3 months, respectively), in contrast to the dogs treated with the 8-mm coils (91%, 79%, and 67% for angiography and Doppler echocardiography at 1,3 days and 3 months, respectively). After 3 months, no residual murmur was found in dogs treated with the 5-mm coils (0/7), in contrast to murmurs in 5 of 12 (42%) dogs treated with the 8-mm coils. Despite incomplete closure in these dogs, volume loading of the left heart decreased in all dogs. Pulmonic or aortic coil embolism did not occur. Analysis of initial results shows that single detachable coil embolization is possible in all dogs with a small PDA (, 4 mm), but only very small PDA (s 2.5) could be treated effectively, and for the moderate PDA (2.6-4.0 mm) longer coils or multiple coils may be necessary to achieve complete occlusion. [source] QSPR Analysis of Copolymers by Recursive Neural Networks: Prediction of the Glass Transition Temperature of (Meth)acrylic Random CopolymersMOLECULAR INFORMATICS, Issue 8-9 2010Carlo Giuseppe Bertinetto Abstract The glass transition temperature (Tg) of acrylic and methacrylic random copolymers was investigated by means of Quantitative Structure-Property Relationship (QSPR) methodology based on Recursive Neural Networks (RNN). This method can directly take molecular structures as input, in the form of labelled trees, without needing predefined descriptors. It was applied to three data sets containing up to 615 polymers (340 homopolymers and 275,copolymers). The adopted representation was able to account for the structure of the repeating unit as well as average macromolecular characteristics, such as stereoregularity and molar composition. The best result, obtained on a data set focused on copolymers, showed a Mean Average Residual (MAR) of 4.9,K, a standard error of prediction (S) of 6.1,K and a squared correlation coefficient (R2) of 0.98 for the test set, with an optimal rate with respect to the training error. Through the treatment of homopolymers and copolymers both as separated and merged data sets, we also showed that the proposed approach is particularly suited for generalizing prediction of polymer properties to various types of chemical structures in a uniform setting. [source] Pulsed Radiofrequency Ablation for Residual and Phantom Limb Pain: A Case SeriesPAIN PRACTICE, Issue 5 2010Matt West MD Abstract Residual limb pain (RLP) and phantom limb pain (PLP) can be debilitating and can prevent functional gains following amputation. High correlations have been reported between RLP and the stump neuromas following amputation. Many treatment methods including physical therapy, medications, and interventions, have been used with limited success. Pulsed radiofrequency ablation (PRFA) has shown promise in treating neuropathic pain because of the inhibition of evoked synaptic activity. We present 4 amputees who were treated with PRFA after failing conservative management for their RLP and PLP. All 4 patients underwent PRFA and demonstrated at least 80% relief of RLP for over 6 months. One patient reported a complete resolution of phantom sensation while another patient had significantly decreased frequency of spontaneous PLP and resolution of evoked PLP. In addition, all patients reported improved overall function including increased prosthetic tolerance and decreased oral pain medications. This case series suggests that PRFA is a viable treatment option which might be used for long-term relief of intractable RLP and/or PLP. [source] Residual-Based Diagnostics for Structural Equation ModelsBIOMETRICS, Issue 1 2009B. N. Sánchez Summary Classical diagnostics for structural equation models are based on aggregate forms of the data and are ill suited for checking distributional or linearity assumptions. We extend recently developed goodness-of-fit tests for correlated data based on subject-specific residuals to structural equation models with latent variables. The proposed tests lend themselves to graphical displays and are designed to detect misspecified distributional or linearity assumptions. To complement graphical displays, test statistics are defined; the null distributions of the test statistics are approximated using computationally efficient simulation techniques. The properties of the proposed tests are examined via simulation studies. We illustrate the methods using data from a study of in utero lead exposure. [source] rhBMP-2/,BSM® Induces Significant Vertical Alveolar Ridge Augmentation and Dental Implant OsseointegrationCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2002Ulf M.E. Wikesjö DDS ABSTRACT Background: Recombinant human bone morphogenetic protein 2 (rhBMP-2) in a carrier has been shown to induce significant bone formation. Several candidate carriers, however, lack structural integrity to offset compressive forces that may compromise rhBMP-2 bone induction, in particular, for challenging onlay indications such as alveolar ridge augmentation. Purpose: The objective of this study was to evaluate rhBMP-2 in a calcium-phosphate cement carrier, ,BSM, for vertical alveolar ridge augmentation and immediate dental implant Osseointegration. Materials and Methods: Six adult Hound Labrador mongrels with 5 mm critical size supra-alveolar peri-implant defects were used. Three animals received rhBMP-2/,BSM (rhBMP-2 at 0.40 and 0.75 mg/mL) in contralateral jaw quadrants (total implant volume/defect , 1.5 mL). Three animals received ,BSM without rhBMP-2 (control group). The animals were euthanized at 16 weeks post surgery, and block biopsies were processed for histologie and histometric analysis. Results: rhBMP-2/,BSM induced substantial augmentation of the alveolar ridge. Control sites exhibited limited new bone formation. Vertical bone augmentation averaged (SD) 4.9 ± 1.0 mm (rhBMP-2 at 0.40 mg/mL), 5.3 ± 0.3 mm (rhBMP-2 at 0.75 mg/mL), and 0.4 ± 0.4 mm (control); new bone area 8.5 ± 4.2 mm 2, 9.0 ± 1.9 mm 2, and 0.5 ± 0.4 mm 2; new bone density 55.1 ± 6.4%, 61.1 ± 6.0%, and 67.7 ± 9.5%; and new bone-implant contact 26.9 ± 17.5%, 28.5 ± 1.4%, and 24.6 ± 16.1%, respectively. Residual ,BSM comprised 1% of the new bone. Bone density for the contiguous resident bone ranged from 65 to 71%, and bone-implant contact ranged from 49 to 64%. Conclusions: Surgical implantation of rhBMP-2/,BSM appears an effective protocol for vertical alveolar ridge augmentation procedures and immediate dental implant Osseointegration and for onlay indications of lesser complexity. [source] Early survival of marble trout Salmo marmoratus: evidence for density dependence?ECOLOGY OF FRESHWATER FISH, Issue 2 2007S. Vincenzi Abstract,,, The role of endogenous and exogenous factors in regulating population dynamics of freshwater salmonids is still a matter of debate. The aim of the present work was to assess the relative importance of density-dependent and -independent factors in determining the survival of marble trout (Salmo marmoratus) yearlings in two populations living in Slovenian streams (Zakojska and Gorska). The investigation was performed by combining a classical life table analysis with Monte Carlo simulation. Size-dependent fecundity was estimated by stripping wild adults in the fish farm. A significant positive relationship was found between length of marble trout females and the number of eggs produced. Egg density was the major determinant of survival from eggs to age 1+ (,0) in both streams. Residuals of the relationship between ,0 and egg density were positively correlated with rainfall only in Zakojska, probably because, within a certain range, more intense rainfalls increases stream flow and, consequently, suitable habitat for trout. Our study shows how density-dependent and environmental factors can interact to determine the survival of marble trout during the first year of life. [source] Methods for the analysis of trends in streamflow response due to changes in catchment conditionENVIRONMETRICS, Issue 7 2001R. A. Letcher Abstract Two algorithms for analysing changes in streamflow response due to changes in land use and farm dam development, based on the Estimated Generalized Least Squares (EGLS) and the Generalized Additive Model (GAM) methods, were compared on three catchments in the Macquarie River Basin in NSW, Australia. In order to account for the influence of climatic conditions on streamflow response, the IHACRES conceptual rainfall-runoff model was calibrated on a daily time step over two-year periods then simulated over the entire period of concurrent rainfall, streamflow and temperature data. Residuals or differences between observed and simulated flows were calculated. The EGLS method was applied to a smoothing of the residual (daily) time series. Such residuals represent the difference between the simulated streamflow response to a fixed catchment condition (in the calibration period) and that due to the actual varying conditions throughout the record period. The GAM method was applied to quarterly aggregated residuals. The methods provided similar qualitative results for trends in residual streamflow response in each catchment for models with a good fitting performance on the calibration period in terms of a number of statistics, i.e. the coefficient of efficiency R2, bias and average relative parameter error (ARPE). It was found that the fit of the IHACRES model to the calibration period is critically important in determining trend values and significance. Models with well identified parameters and less correlation between rainfall and model residuals are likely to give the best results for trend analysis. Copyright © 2001 John Wiley & Sons, Ltd. [source] Floristic biogeography of the Hawaiian Islands: influences of area, environment and paleogeographyJOURNAL OF BIOGEOGRAPHY, Issue 3 2004Jonathan P. Price Abstract Aim, A detailed database of distributions and phylogenetic relationships of native Hawaiian flowering plant species is used to weigh the relative influences of environmental and historical factors on species numbers and endemism. Location, The Hawaiian Islands are isolated in the North Pacific Ocean nearly 4000 km from the nearest continent and nearly as distant from the closest high islands, the Marquesas. The range of island sizes, environments, and geological histories within an extremely isolated archipelago make the Hawaiian Islands an ideal system in which to study spatial variation in species distributions and diversity. Because the biota is derived from colonization followed by extensive speciation, the role of evolution in shaping the regional species assemblage can be readily examined. Methods, For whole islands and regions of each major habitat, species,area relationships were assessed. Residuals of species,area relationships were subjected to correlation analysis with measures of endemism, isolation, elevation and island age. Putative groups of descendents of each colonist from outside the Hawaiian Islands were considered phylogenetic lineages whose distributions were included in analyses. Results, The species,area relationship is a prominent pattern among islands and among regions of each given habitat. Species number in each case correlates positively with number of endemics, number of lineages and number of species per lineage. For mesic and wet habitat regions, island age is more influential than area on species numbers, with older islands having more species, more single-island endemics, and higher species : lineage ratios than their areas alone would predict. Main conclusions, Because species numbers and endemism are closely tied to speciation in the Hawaiian flora, particularly in the most species-rich phylogenetic lineages, individual islands' histories are central in shaping their biota. The Maui Nui complex of islands (Maui, Moloka,i, L,na,i and Kaho,olawe), which formed a single large landmass during most of its history, is best viewed in terms of either the age or area of the complex as a whole, rather than the individual islands existing today. [source] High Moment Partial Sum Processes of Residuals in ARMA Models and their ApplicationsJOURNAL OF TIME SERIES ANALYSIS, Issue 1 2007Hao Yu Abstract., In this article, we study high moment partial sum processes based on residuals of a stationary autoregressive moving average (ARMA) model with known or unknown mean parameter. We show that they can be approximated in probability by the analogous processes which are obtained from the i.i.d. errors of the ARMA model. However, if a unknown mean parameter is used, there will be an additional term that depends on model parameters and a mean estimator. When properly normalized, this additional term will vanish. Thus the processes converge weakly to the same Gaussian processes as if the residuals were i.i.d. Applications to change-point problems and goodness-of-fit are considered, in particular, cumulative sum statistics for testing ARMA model structure changes and the Jarque,Bera omnibus statistic for testing normality of the unobservable error distribution of an ARMA model. [source] Default Bayesian Priors for Regression Models with First-Order Autoregressive ResidualsJOURNAL OF TIME SERIES ANALYSIS, Issue 3 2003Malay Ghosh Abstract. The objective of this paper is to develop default priors when the parameter of interest is the autocorrelation coefficient in normal regression models with first-order autoregressive residuals. Jeffreys' prior as well as reference priors are found. These priors are compared in the light of how accurately the coverage probabilities of Bayesian credible intervals match the corresponding frequentist coverage probabilities. It is found that the reference priors have a definite edge over Jeffreys' prior in this respect. Also, the credible intervals based on these reference priors seem superior to similar intervals based on certain divergence measures. [source] Congenital Cholesteatoma: Risk Factors for Residual Disease and Retraction Pockets,A Report on 117 Cases,THE LARYNGOSCOPE, Issue 4 2007Diane S. Lazard MD Abstract Objectives: To define predictors of residuals and retraction pockets (RP) in children operated on for congenital cholesteatoma (CC). Design and Setting: Retrospective review (1996,2005), academic center. Patients: One hundred seventeen patients treated for CC corresponding to modified Derlacki's criteria were included (median age, 6.5 yr). No case of RP at time of diagnosis, with a mean follow-up of 2.5 years after last surgery. Main Outcome Measures: Clinical and surgical data influencing outcome. Multivariate analysis. Results: Two groups were defined after CC removal: group I (12 cases), no second look required and no case of subsequent re-intervention; group II (105 cases), planned second look always performed (mean delay, 12.1 mo), no difference of sex ratio (M/F = 2). Group I patients were younger than in group II (3.3 vs. 5.9 yr, P < .001). All of them had a normal contralateral eardrum and a disclosure of CC by routine examination (vs. 19% in group II, P < .001). In group I, the mass occupied one or two anterior quadrants (41.6% and 58.4%, respectively) versus more than two quadrants in 46.6% in group II. Residuals and RP rates were 41% and 15%, respectively (only in group II). Predictors for residuals were atticotomy (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.3,6.7) and destruction of stapes (OR 4.3, 95% CI 1.7,10.5). Predictors for RP were eustachian tube extension (OR 6.8, 95% CI 1.7,26.8) and nonreconstructed atticotomy (OR 5.9, 95% CI 1.1,30.9). Conclusions: Young children with small CC had no recurrences. Residuals were more frequent in case of atticotomy and stapes destruction. RP occurred especially in cases of eustachian tube extension and if cartilage tympanoplasty was not performed. Tympanic and canal wall reinforcement should be considered in extensive CC. [source] Spatial Cluster Detection for Weighted Outcomes Using Cumulative Geographic ResidualsBIOMETRICS, Issue 3 2010Andrea J. Cook Summary Spatial cluster detection is an important methodology for identifying regions with excessive numbers of adverse health events without making strong model assumptions on the underlying spatial dependence structure. Previous work has focused on point or individual-level outcome data and few advances have been made when the outcome data are reported at an aggregated level, for example, at the county- or census-tract level. This article proposes a new class of spatial cluster detection methods for point or aggregate data, comprising of continuous, binary, and count data. Compared with the existing spatial cluster detection methods it has the following advantages. First, it readily incorporates region-specific weights, for example, based on a region's population or a region's outcome variance, which is the key for aggregate data. Second, the established general framework allows for area-level and individual-level covariate adjustment. A simulation study is conducted to evaluate the performance of the method. The proposed method is then applied to assess spatial clustering of high Body Mass Index in a health maintenance organization population in the Seattle, Washington, USA area. [source] Multiple-Imputation-Based Residuals and Diagnostic Plots for Joint Models of Longitudinal and Survival OutcomesBIOMETRICS, Issue 1 2010Dimitris Rizopoulos Summary The majority of the statistical literature for the joint modeling of longitudinal and time-to-event data has focused on the development of models that aim at capturing specific aspects of the motivating case studies. However, little attention has been given to the development of diagnostic and model-assessment tools. The main difficulty in using standard model diagnostics in joint models is the nonrandom dropout in the longitudinal outcome caused by the occurrence of events. In particular, the reference distribution of statistics, such as the residuals, in missing data settings is not directly available and complex calculations are required to derive it. In this article, we propose a multiple-imputation-based approach for creating multiple versions of the completed data set under the assumed joint model. Residuals and diagnostic plots for the complete data model can then be calculated based on these imputed data sets. Our proposals are exemplified using two real data sets. [source] Cluster Detection Based on Spatial Associations and Iterated Residuals in Generalized Linear Mixed ModelsBIOMETRICS, Issue 2 2009Tonglin Zhang Summary Spatial clustering is commonly modeled by a Bayesian method under the framework of generalized linear mixed effect models (GLMMs). Spatial clusters are commonly detected by a frequentist method through hypothesis testing. In this article, we provide a frequentist method for assessing spatial properties of GLMMs. We propose a strategy that detects spatial clusters through parameter estimates of spatial associations, and assesses spatial aspects of model improvement through iterated residuals. Simulations and a case study show that the proposed method is able to consistently and efficiently detect the locations and magnitudes of spatial clusters. [source] Model-Checking Techniques Based on Cumulative ResidualsBIOMETRICS, Issue 1 2002D. Y. Lin Summary. Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes under the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided. [source] Regional industrial recycling network in energy supply,the case of Joensuu city, FinlandCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 3 2002Jouni Korhonen Industrial recycling networks offer an example of the practical application of some of the industrial ecology (IE) principles. In the industrial ecosystem and eco-industrial park approaches the material cycles and energy cascades in a natural ecosystem serve as the metaphoric vision for a local/regional industrial system in which waste material and waste (residual) energy are utilized through cooperation between the actors in the system. In this paper, a local/regional recycling network scenario is presented with the energy supply system of the city of Joensuu in Finland. The conditions of success include the co-production of heat and electricity (heat and power, CHP), waste energy utilization for industrial steam and renewable flow use as fuel. Some difficulties in the industrial ecosystem-type development of the system are discussed. Methodological suggestions for industrial ecosystem and eco-industrial park case studies are considered and the experience from this Finnish case is discussed in terms of wider application of IE in local/regional economic energy systems. For future research on the theme, it is suggested that regional industrial ecology may benefit from regional economics theory and, vice versa, regional economics theory may find a new area of application in regional industrial ecology. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment. [source] Orthopaedic issues in the musculoskeletal care of adults with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 2009HELEN M HORSTMANN MD Aims, Orthopaedic care of adults with cerebral palsy (CP) has not been well documented in orthopaedic literature. This paper focuses on some of the common problems which present themselves when adults with CP seek orthopaedic intervention. In particular, we review the most common orthopaedic issues which present to the Penn Neuro-Orthopaedics Program. Method, A formal review of consecutive surgeries performed by the senior author on adults with CP was previously conducted. This paper focuses on the health delivery care for the adult with orthopaedic problems related to cerebral palsy. Ninety-two percent of these patients required lower extremity surgery. Forty percent had procedures performed on the upper extremities. Results, The majority of problems seen in the Penn Neuro-Orthopaedics Program are associated with the residuals of childhood issues, particularly deformities associated with contractures. Patients are also referred for treatment of acquired musculoskeletal problems such as degenerative arthritis of the hip or knee. A combination of problems contribute most frequently to foot deformities and pain with weight-bearing, shoewear or both, most often due to equinovarus. The surgical correction of this is most often facilitated through a split anterior tibial tendon transfer. Posterior tibial transfers are rarely indicated. Residual equinus deformities contribute to a pes planus deformity. The split anterior tibial tendon transfer is usually combined with gastrocnemius-soleus recession and plantar release. Transfer of the flexor digitorum longus to the os calcis is done to augment the plantar flexor power. Rigid pes planus deformity is treated with a triple arthrodesis. Resolution of deformity allows for a good base for standing, improved ability to tolerate shoewear, and/or braces. Other recurrent or unresolved issues involve hip and knee contractures. Issues of lever arm dysfunction create problems with mechanical inefficiency. Upper extremity intervention is principally to correct contractures. Internal rotation and adductor tightness at the shoulder makes for difficult underarm hygiene and predispose a patient to a spiral fracture of the humerus. A tight flexor, pronation pattern is frequently noted through the elbow and forearm with further flexion contractures through the wrist and fingers. Lengthenings are more frequently performed than tendon transfers in the upper extremity. Arthrodesis of the wrist or on rare occasions of the metacarpal-phalangeal joints supplement the lengthenings when needed. Conclusions, The Penn Neuro-Orthopaedics Program has successfully treated adults with both residual and acquired musculoskeletal deformities. These deformities become more critical when combined with degenerative changes, a relative increase in body mass, fatigue, and weakness associated with the aging process. [source] Glucose counterregulation in Type 2 diabetes mellitusDIABETIC MEDICINE, Issue 7 2001B. E. De Galan Abstract Glucose counterregulatory failure and hypoglycaemia unawareness frequently complicate treatment of Type 1 diabetes mellitus, especially when aiming for intensive metabolic control. Since tight metabolic control reduces microvascular long-term complications in Type 2 diabetes mellitus, the integrity of glucose counterregulation in Type 2 diabetic patients is important. Using a Medline search, we identified 12 studies in which counterregulatory responses to insulin-induced hypoglycaemia were compared between Type 2 diabetic patients and appropriate controls. A review of these studies showed that some patients with Type 2 diabetes mellitus develop mild counterregulatory dysfunction and reduced awareness of insulin-induced hypoglycaemia. Some studies suggested an association between counterregulatory impairment and intensity of metabolic control. We speculate that the relatively low frequency of (severe) hypoglycaemic events in Type 2 diabetes may explain why glucose counterregulation remains unaffected in most patients. We hypothesize that residual ,-cell reserve and insulin resistance provide protection against severe hypoglycaemia and limit impaired counterregulation. Diabet. Med. 18, 519,527 (2001) [source] The role of surveillance endoscopy and endosonography after endoscopic ablation of high-grade dysplasia and carcinoma of the esophagusDISEASES OF THE ESOPHAGUS, Issue 2 2008A. D. Savoy SUMMARY., Barrett's esophagus (BE) with high-grade dysplasia (HGD) or early carcinoma treated with surgery or photodynamic therapy (PDT) is at risk of recurrence. The efficacy of endoscopic ultrasound (EUS) for surveillance after PDT is unknown. Our objective was to determine if EUS is superior to esophagogastroduodenoscopy (EGD) and/or CT scan for surveillance of BE neoplasia after PDT. The study was designed as a retrospective review with the setting as a tertiary referral center. Consecutive patients with BE with HGD or carcinoma in situ treated with PDT were followed with EUS, CT scan and EGD with jumbo biopsies every 1 cm at 3, 4, or 6-month intervals. Exclusion criteria was < 6 months of follow up and/or < 2 EUS procedures. Main outcome measurements were residual or recurrent disease discovered by any method. Results showed that 67/97 patients met the inclusion criteria (56 men and 11 women). Median follow-up was 16 months. Recurrent or residual adenocarcinoma (ACA) was detected in four patients during follow-up. EGD with random biopsies or targeted nodule biopsies detected three patients. EUS with endoscopic mucosal resection of the nodule confirmed T1 recurrence in one of these three. In the fourth patient, CT scan revealed perigastric lymphadenopathy and EUS-FNA (fine needle aspiration) confirmed adenocarcinoma. There were two deaths, one related to disease progression and one unrelated. The rate of recurrent/persistent ACA after PDT was 4/67 = 6%. EUS did not detect disease when EGD and CT were normal. Limitations of this study include non-blinding of results and preferential status of non-invasive imaging (CT) over EUS. Our experience suggests that EUS has little role in the surveillance of these patients, unless discrete abnormalities are found on EGD or cross-sectional imaging. [source] Dunefoot dynamics along the Dutch coastEARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2002B. G. Ruessink Abstract The dynamics of the dunefoot along a 160 km portion of the Dutch coast has been investigated based on a data set of annual surveys dating back to as early as 1850. The linearly detrended (or residual) dunefoot positions comprise an alongshore uniform and an alongshore non-uniform component. The former is expressed as 10 to 15 m of landward retreat along extensive (>10 km) stretches of coast during years with severe storm surges and as up to 5 m of seaward advance during years without significant storm activity. The latter, alongshore non-uniform component is organized in sandwave-like patterns, which may have a longevity of decades to up to the duration of the entire data set (150 years). Their wavelengths vary along the coast, from 3·5 to 10 km; migration rates are 0,200 m a,1. Dunefoot sandwaves are shown to be the shoreward extensions of similar sandwave patterns in the beach position. The non-uniform dunefoot behaviour constitutes at least 80 per cent of the total residual dunefoot dynamics, implying that along the Dutch coast residual dunefoot variability is controlled by temporal and spatial variability in beach characteristics, and not by storm-induced uniform erosion. Various potential mechanisms causing beach sandwaves are discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source] Evaluation of residual drift demands in regular multi-storey frames for performance-based seismic assessmentEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 13 2006Jorge Ruiz-García Abstract This paper summarizes results of a comprehensive analytical study aimed at evaluating the amplitude and heightwise distribution of residual drift demands in multi-storey moment-resisting frames after earthquake excitation. For that purpose, a family of 12 one-bay two-dimensional generic frame models was subjected to an ensemble of 40 ground motions scaled to different intensities. In this investigation, an inelastic ground motion intensity measure was employed to scale each record, which allowed reducing the record-to-record variability in the estimation of residual drift demands. The results were statistically processed in order to evaluate the influence of ground motion intensity, number of stories, period of vibration, frame mechanism, system overstrength, and hysteretic behaviour on central tendency of residual drift demands. In addition, a special emphasis was given to evaluate the uncertainty in the estimation of residual drift demands. Results of incremental dynamic analyses indicate that the amplitude and heightwise distribution of residual drift demands strongly depends on the frame mechanism, the heightwise system structural overstrength and the component hysteretic behaviour. An important conclusion for performance-based assessment is that the evaluation of residual drift demands involves significantly larger levels of uncertainty (i.e. record-to-record variability) than that of maximum drift demands, which suggests that this variability and corresponding uncertainty should be explicitly taken into account when estimating residual drift demands during performance-based seismic assessment of frame buildings. Copyright © 2006 John Wiley & Sons, Ltd. [source] Electrochemical Determination of a Free Chlorine Residual Using Cathodic Potential-Step ChronocoulometryELECTROANALYSIS, Issue 8 2005Shin-ya Kishioka Abstract The cathodic reaction of chlorine residual (CR) combined with anodic pre-electrolysis enables the quantification of CR as a gaseous chlorine. Potential-step chronocoulometry was successfully applied to extend the CR detection range. [source] Modeling the environmental fate of perfluorooctanoate and its precursors from global fluorotelomer acrylate polymer useENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Rosalie van Zelm Abstract The environment contains various direct and indirect sources of perfluorooctanoic acid (PFOA). The present study uses a dynamic multispecies environmental fate model to analyze the potential formation of perfluorooctanoate (PFO), the anion of PFOA, in the environment from fluorotelomer acrylate polymer (FTacrylate) emitted to landfills and wastewater, residual fluorotelomer alcohol (8:2 FTOH) in FTacrylate, and residual PFOA in FTacrylate. A multispecies version of the SimpleBox model, which is capable of determining the fate of a chemical and its degradation products, was developed for this purpose. An uncertainty analysis on the chemical-specific input parameters was performed to examine for uncertainty in modeled concentrations. In 2005, residual 8:2 FTOH made up 80% of the total contribution of FTacrylate use to PFO concentrations in global oceans, and residual PFOA in FTacrylate contributed 15% to PFO concentrations from FTacrylate use in global oceans. After hundreds of years, however, the main source of PFO from total historical FTacrylate production is predicted to be FTacrylate degrading in soil following land application of sludge from sewage treatment plants, followed by FTacrylate still present in landfills. Uncertainty in modeled PFO concentrations was up to a factor of 3.3. Current FTacrylate use contributes less than 1% of the PFO in seawater, but because direct PFOA emission sources are reduced and PFOA continues to be formed from FTacrylate in soil and in landfills, this fraction grows over time. [source] Evaluation of statistical methods for left-censored environmental data with nonuniform detection limitsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2006Parikhit Sinha Abstract Monte Carlo simulations were used to evaluate statistical methods for estimating 95% upper confidence limits of mean constituent concentrations for left-censored data with nonuniform detection limits. Two primary scenarios were evaluated: data sets with 15 to 50% nondetected samples and data sets with 51 to 80% nondetected samples. Sample size and the percentage of nondetected samples were allowed to vary randomly to generate a variety of left-censored data sets. All statistical methods were evaluated for efficacy by comparing the 95% upper confidence limits for the left-censored data with the 95% upper confidence limits for the noncensored data and by determining percent coverage of the true mean (,). For data sets with 15 to 50% nondetected samples, the trimmed mean, Winsorization, Aitchison's, and log-probit regression methods were evaluated. The log-probit regression was the only method that yielded sufficient coverage (99,100%) of ,, as well as a high correlation coefficient (r2 = 0.99) and small average percent residuals (, 0.1%) between upper confidence limits for censored versus noncensored data sets. For data sets with 51 to 80% nondetected samples, a bounding method was effective (r2 = 0.96,0.99, average residual = ,5% to ,7%, 95-98% coverage of ,), except when applied to distributions with low coefficients of variation (standard deviation/, < 0.5). Thus, the following recommendations are supported by this research: data sets with 15 to 50% nondetected samples,log-probit regression method and use of Chebyshev theorem to estimate 95% upper confidence limits; data sets with 51 to 80% nondetected samples, bounding method and use of Chebyshev theorem to estimate 95% upper confidence limits. [source] Pyrene and chrysene fate in surface soil and sand microcosmsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2001J. Chadwick Roper Abstract Polycyclic aromatic hydrocarbons (PAHs) are major components of wastes from municipal gas plants and many wood preservatives. Soil contaminated with these wastes is a potential threat to human health because of the carcinogenicity of many PAHs. This study follows the fate of two four-ring PAHs, pyrene and chrysene, in three matrices: an adapted soil (obtained from a site contaminated with PAHs for more than 75 years), an uncontaminated soil (with and without an inoculum of adapted soil), and sand mixed with an inoculum of adapted soil. Radiolabeled pyrene, chrysene, and salicylic acid (a metabolite of PAH biodegradation) were used to trace the mineralization, transformation, extractability, and formation of an unextractable residual over time. Linear approximations of the rates of these processes were made. High-performance liquid chromatography (HPLC) analysis of extracts from inoculated soil showed the transient formation of two known metabolites: 1-hydroxypyrene (from pyrene) and 1-hydroxy-2-naphthoic acid (from chrysene). The amount of extractable label diminished steadily over the course of the study in systems that were not inhibited with sodium azide, whereas the amount of extractable label remained relatively constant in inhibited systems. Correspondingly, the amount of nonextractable residual label generally increased during each incubation in uninhibited systems, whereas the amount of this residual label remained relatively constant in inhibited systems. In contrast, the rate and extent of mineralization varied widely across matrix types. This suggests that alterations of the PAH that impact extractability and residual formation are common, in contrast to mineralization, which was apparently limited to adapted communities. [source] Predicting intra-urban variation in air pollution concentrations with complex spatio-temporal dependencies,ENVIRONMETRICS, Issue 6 2010Adam A. Szpiro Abstract We describe a methodology for assigning individual estimates of long-term average air pollution concentrations that accounts for a complex spatio-temporal correlation structure and can accommodate spatio-temporally misaligned observations. This methodology has been developed as part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), a prospective cohort study funded by the US EPA to investigate the relationship between chronic exposure to air pollution and cardiovascular disease. Our hierarchical model decomposes the space--time field into a "mean" that includes dependence on covariates and spatially varying seasonal and long-term trends and a "residual" that accounts for spatially correlated deviations from the mean model. The model accommodates complex spatio-temporal patterns by characterizing the temporal trend at each location as a linear combination of empirically derived temporal basis functions, and embedding the spatial fields of coefficients for the basis functions in separate linear regression models with spatially correlated residuals (universal kriging). This approach allows us to implement a scalable single-stage estimation procedure that easily accommodates a significant number of missing observations at some monitoring locations. We apply the model to predict long-term average concentrations of oxides of nitrogen (NOx) from 2005 to 2007 in the Los Angeles area, based on data from 18 EPA Air Quality System regulatory monitors. The cross-validated IR2 is 0.67. The MESA Air study is also collecting additional concentration data as part of a supplementary monitoring campaign. We describe the sampling plan and demonstrate in a simulation study that the additional data will contribute to improved predictions of long-term average concentrations. Copyright © 2009 John Wiley & Sons, Ltd. [source] Mapping sea bird densities over the North Sea: spatially aggregated estimates and temporal changesENVIRONMETRICS, Issue 6 2005Edzer J. Pebesma Abstract In the Dutch sector of the North Sea, sea bird densities are recorded bi-monthly by using airborne strip-transect monitoring. From these data we try to estimate: (i) high-resolution spatial patterns of sea bird densities; (ii) low-resolution spatial-average bird densities for large areas; and (iii) temporal changes in (i) and (ii), using data on Fulmaris glacialis as an example. For spatial estimation, we combined Poisson regression for modelling the trend as a function of water depth and distance to coast with kriging interpolation of the residual variability, assuming spatial (co)variances to be proportional to the trend value. Spatial averages were estimated by block kriging. For estimating temporal differences we used residual cokriging for two consecutive years, and show how this can be extended to analyse trends over multiple years. Approximate standard errors are obtained for all estimates. A comparison with a residual simple kriging approach reveals that ignoring temporal cross-correlations leads to a severe loss of statistical accuracy when assessing the significance of temporal changes. This article shows results for Fulmaris glacialis monitored during August/September in 1998 and 1999. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||