bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lung growth and function in children and adolescents with idiopathic pectus excavatum
Authors: Koumbourlis Anastassios C. , Stolar Charles J. 
Published: August 2004

AbstractPatterns of lung growth and function were studied retrospectively in 103 patients (73 male and 30 female) with idiopathic pectus excavatum in order to determine: 1) the prevalence of restrictive lung defect and/or other lung function abnormalities; 2) the possible association between type of lung function abnormalities and age of the patient; and 3) whether the type of lung function is associated with other clinical conditions. Forty‐three patients (42%) were between 5–9 years of age; 36 (35%) were between 10–14 years; and 24 (23%) were between 15–19 years. Restrictive lung disease was detected only in 5 patients (5%), whereas 42 patients (41%) had evidence of obstructive pattern, and the remaining 56 patients (54%) had a normal pattern. The mean values for lung volume (total lung capacity (TLC) and/or forced vital capacity (FVC)) were lowest in the 10–14‐year group, whereas the mean values of the indices of lower airway function (forced expiratory volume at 1 sec (FEV1), FEV1/FVC, forced expiratory flow at 25–75% of forced vital capacity (FEF25–75), and FEF25–75/FVC) were higher in the younger group. Residual volume (RV) and RV/TLC were elevated in all age groups, but they declined toward normalization with increasing age. There were no significant differences between groups (stratified either by pattern of lung function or by age) with regard to their demographics or clinical characteristics (scoliosis, direction of sternal rotation, history of asthma/reactive airways disease, or exercise intolerance). We conclude that idiopathic pectus excavatum may be associated with a variety of lung function abnormalities (in particular, lower airway obstruction) even in the absence of overt clinical symptoms. There was no evidence of significant worsening of lung function with increasing age. Pediatr Pulmonol. 2004; 38:339–343. © 2004 Wiley‐Liss, Inc.
Structure–activity relationship study on human urotensin II
Authors: Guerrini Remo , Camarda Valeria , Marzola Erika , Arduin Marika , Calo Girolamo , Spagnol Martina , Rizzi Anna , Salvadori Severo , Regoli Domenico 
Published: August 2004

AbstractThe vasoactive cyclic undecapeptide urotensin‐II (U‐II) has been identified as an endogenous ligand for the G‐protein coupled receptor now referred to as the UT receptor. The U‐II/UT receptor system might be relevant for cardiovascular functions. A structure‐activity study of human U‐II investigating 31 peptides in the rat aorta bioassay is reported. Ala‐ and D‐scan investigations indicated that the sequence Phe6‐Trp7‐Lys8‐Tyr9 is essential for biological activity and that Lys8 and Tyr9 are particularly important. These two residues were substituted with a series of coded and non‐coded amino acids. These studies demonstrated that the positive charge of the primary aliphatic amine at position 8 and its relative spatial orientation is crucial for both receptor occupation and activation, while the only chemical requirement at position 9 is the presence of an aromatic moiety. Moreover, this study led to the identification of UT receptor partial agonists (compounds 23 and 24) which can be used as chemical templates for further investigations aimed at the identification of selective antagonists. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
The use of remotely sensed data to detect channel hydromorphology; River Tummel, Scotland
Authors: Gilvear David J. , Davids Corine , Tyler Andrew N. 
Published: August 2004

AbstractColour aerial photography and multi‐spectral imagery acquired from airborne platforms for the River Tummel, Scotland, was used in conjunction with field survey to assess the feasibility of monitoring hydromorphology and human alteration within the river corridor. The study was undertaken to investigate the possibility of remotely sensing the physical status of a nation's rivers at the national scale to comply with the requirement of the European Water Framework Directive. Visual assessment and unsupervised and supervised automated classifications of the imagery were undertaken and compared with field survey data.In the absence of overhanging vegetation canopies most features above the water line of interest were visible on the imagery. Below the water line, morphology and substrate composition together with bank materials on vertically cut banks are less easily detected. The overall accuracy of automated classification procedures, compared to field survey, was 60% for the colour aerial photography and 68% for the multi‐spectral imagery. Supervised classification was superior to unsupervised classification procedures. Sun glint on water surfaces and shadows caused by high banks, trees and buildings were observed as the cause of most misclassification of features.Overall, the study demonstrates that remotely sensed digital imagery has the potential to allow panoptic mapping of river hydromorphology and human impacts. The possibilities and constraints, in light of the findings of this study, are discussed. In the context of new legislation which requires environmental protection agencies to have robust tools for monitoring the physical status, as part of meeting the objective of good ecological status, of rivers across an entire nation, remote sensing appears to provide a way forward. Copyright © 2004 John Wiley & Sons, Ltd.
Evolutionary computation to control unnatural water level fluctuations in multi‐reservoir river systems
Authors: Dessalegne Tibebe , Nicklow John , Minder Eric 
Published: August 2004

AbstractA methodology and computational model for evaluation and optimization of dam operations in multi‐reservoir river systems is presented. The optimal dam operation scheme was defined as that which minimizes unnatural water level fluctuations during low flow periods, subject to the maintenance of desired stages within the river network, desired storage levels in the reservoirs, and bounds on releases from dams. The dam operation problem was solved using a discrete‐time optimal control methodology in which a genetic algorithm was interfaced with an existing, unsteady, one‐dimensional hydraulic simulation model known as FLDWAV. The hydraulic simulation model was used to solve governing hydraulic constraints, while the genetic algorithm was employed to solve the overall control problem. Constraints on water surface and storage levels were handled using an Additive Penalty Method. Two types of objective functions, absolute water surface deviation and rate of water surface fluctuation, were considered and their results were compared. Capabilities of the overall model were demonstrated through applications to a hypothetical three‐reservoir river system and a portion of the Illinois River Waterway, for which the hydraulic simulation model was calibrated and verified. Copyright © 2004 John Wiley & Sons, Ltd.
Interactive effects of basin features and land‐use change on macroinvertebrate communities of headwater streams in the Patagonian Andes
Authors: Miserendino M. Laura , Pizzolon Lino A. 
Published: August 2004

AbstractComposition and structure of macroinvertebrate communities were documented in relation to hydrochemical variables over a 10‐month period in four headwater tributaries of the Futaleufú River, northwestern Chubut, Argentina. The streams are located along the strong rainfall gradient that decreases from west to east and they have different basin features. At Blanco and Baggilt streams, riparian vegetation consisted primarily of native Nothofagus forest, while in the Nant y Fall and Rifleros, basins with a long legacy of domestic grazing, the introduced Salix fragilis was the dominant riparian species. Macroinvertebrate species richness, density, and biomass were similar among rivers; however, biomass of shredders was highest in the Nothofagus forested streams and collector‐filterers were significantly higher in Salix fragilis‐bordered rivers. Water temperatures were higher in non‐native Salix sites than in the native or mixed forested sites. Canonical community analysis indicated community composition was related to geomorphic attributes of the rivers, especially slope, basin height (elevation change), distance to the source, substratum size, and Salix coverage. Moreover, seasonally dynamic variables, rainfall and water temperature were good community predictors. Land‐use change (conversion from Nothofagus to pastures and the Salix fragilis invasion in the riverbanks of pasture‐dominated catchments) was interactive with natural stream attributes as determinants of macroinvertebrate distribution and abundance. Copyright © 2004 John Wiley & Sons, Ltd.
TOPS (Task Optimization in the Presence of Signal‐Dependent Noise) model
Authors: Miyamoto Hiroyuki , Nakano Eri , Wolpert Daniel M. , Kawato Mitsuo 
Published: August 2004

AbstractThis paper proposes a movement trajectory planning model, which is a maximum task achievement model in which signal‐dependent noise is added to the movement command. In the proposed model, two optimization criteria are combined, maximum task achievement and minimum energy consumption. The proposed model has the feature that the end‐point boundary conditions for position, velocity, and acceleration need not be prespecified. Consequently, the method can be applied not only to the simple point‐to‐point movement, but to any task. In the method in this paper, the hand trajectory is derived by a psychophysical experiment and a numerical experiment for the case in which the target is not stationary, but is a moving region. It is shown that the trajectory predicted from the minimum jerk model or the minimum torque change model differs considerably from the results of the psychophysical experiment. But the trajectory predicted from the maximum task achievement model shows good qualitative agreement with the hand trajectory obtained from the psychophysical experiment. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(11): 48–58, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10377
Latent variable modelling of recovery trajectories: sexual function following radical prostatectomy
Authors: Legler Julie M. , Davis William W. , Potosky Arnold L. , Hoffman Richard M. 
Published: August 2004

AbstractAs treatments improve and survival time lengthens, the course of recovery and long‐term quality of life (QoL) is of greater interest. The application of latent class growth models to longitudinal QoL data provides unique insights into recovery that are not evident with marginal analyses. We examine this approach in the context of a large population‐based observational study. This is the first attempt to characterize individuals' recovery over time following prostate cancer surgery, and to determine factors associated with varying recovery experiences of prostate cancer patients. Four major patterns emerged that illustrate typical patterns of recovery following radical prostatectomy. Given a man's baseline data, this method produces estimates of the probability of belonging to each recovery class. The method is presented as a useful tool for identifying hypotheses associated with recovery and potential antecedents of importance. Published in 2004 by John Wiley & Sons, Ltd.
Stratification and weighting via the propensity score in estimation of causal treatment effects: a comparative study
Authors: Lunceford Jared K. , Davidian Marie 
Published: August 2004

AbstractEstimation of treatment effects with causal interpretation from observational data is complicated because exposure to treatment may be confounded with subject characteristics. The propensity score, the probability of treatment exposure conditional on covariates, is the basis for two approaches to adjusting for confounding: methods based on stratification of observations by quantiles of estimated propensity scores and methods based on weighting observations by the inverse of estimated propensity scores. We review popular versions of these approaches and related methods offering improved precision, describe theoretical properties and highlight their implications for practice, and present extensive comparisons of performance that provide guidance for practical use. Copyright © 2004 John Wiley & Sons, Ltd.
Experience with the architectural design of a modest product family
Authors: Schwanke Robert W. , Lutz Robyn R. 
Published: August 2004

AbstractMany product families are modest in the sense that they consist of a sequence of incremental products with, at any point in time, only a few distinct products available and minimal variations among the products. Such product families, nevertheless, are often large, complex systems, widely deployed, and possessing stringent safety and performance requirements. This paper describes a case study that tends to confirm the value of using a product‐line approach for the architectural design of a modest product family. The paper describes the process, design alternatives, and lessons learned, both positive and negative, from the architectural design of one such family of medical image analysis products. Realized benefits included identifying previously unrecognized common behavior and sets of features that were likely to change together, aligning the architecture with specific market needs and with the organization, and reducing unplanned dependencies. Most interesting were the unanticipated benefits, including decoupling the product‐family architecture from the order of implementation of features, and using the product‐family architecture as a ‘guiding star’ with subsequent releases moving toward, rather than away from, the planned architecture. Copyright © 2004 John Wiley & Sons, Ltd.
Source model analysis using the JJTraveler visitor combinator framework
Authors: van Deursen Arie , Visser Joost 
Published: August 2004

AbstractProgram understanding tools manipulate program representations, such as abstract syntax trees, control‐flow graphs, or data‐flow graphs. This paper deals with the use of visitor combinators to conduct such manipulations. Visitor combinators are an extension of the well‐known visitor design pattern. They are small, reusable classes that carry out specific visiting steps. They can be composed in different constellations to build more complex visitors. We evaluate the expressiveness, reusability, ease of development, and applicability of visitor combinators to the construction of program understanding tools. To that end, we conduct a case study in the use of visitor combinators for control‐flow analysis and visualization as used in a commercial Cobol program understanding tool. Copyright © 2004 John Wiley & Sons, Ltd.
Enforcing direct communications between clients and Web servers to improve proxy performance and security
Authors: Chen Songqing , Zhang Xiaodong 
Published: August 2004

AbstractThe amount of dynamic Web contents and secured e‐commerce transactions has been dramatically increasing on the Internet, where proxy servers between clients and Web servers are commonly used for the purpose of sharing commonly accessed data and reducing Internet traffic. A significant and unnecessary Web access delay is caused by the overhead in proxy servers to process two types of accesses, namely dynamic Web contents and secured transactions, not only increasing response time, but also raising some security concerns. Conducting experiments on Squid proxy 2.3STABLE4, we have quantified the unnecessary processing overhead to show its significant impact on increased client access response times. We have also analyzed the technical difficulties in eliminating or reducing the processing overhead and the security loopholes based on the existing proxy structure. In order to address these performance and security concerns, we propose a simple but effective technique from the client side that adds a detector interfacing with a browser. With this detector, a standard browser, such as the Netscape/Mozilla, will have simple detective and scheduling functions, called a detective browser. Upon an Internet request from a user, the detective browser can immediately determine whether the requested content is dynamic or secured. If so, the browser will bypass the proxy and forward the request directly to the Web server; otherwise, the request will be processed through the proxy. We implemented a detective browser prototype in Mozilla version 0.9.7, and tested its functionality and effectiveness. Since we have simply moved the necessary detective functions from a proxy server to a browser, the detective browser introduces little overhead to Internet accessing, and our software can be patched to existing browsers easily. Copyright © 2004 John Wiley & Sons, Ltd.
Congenital curly toe of the fetus
Authors: Cho J. Y. , Park J. H. , Kim J. H. , Lee Y. H. 
Published: August 2004

AbstractObjectivesTo assess the prevalence, prenatal detection rate, and associated anomalies of congenital curly toe in an unselected obstetric population.MethodsBetween September 2001 and July 2002, 1167 singleton fetuses in the second and third trimesters underwent routine prenatal ultrasound at our hospital. Congenital curly toe was diagnosed when the fourth or fifth toe was not fully delineated on the axial image with medial and plantar flexion on the coronal image. All neonates underwent a physical examination within 3 days after delivery. Radiography was performed on those infants with curly toe. We assessed the prevalence, prenatal detection rate, and associated anomalies of the condition.ResultsThere were 38 congenital curly toes among the 1167 neonates, yielding a total prevalence of 32.6 per 1000. In 26 of the 38 the fourth toe was curly and in 12 the fifth toe was curly. Of those in which the fourth toe was curly, 26.9% involved the right toe, 65.4% the left, and 7.7% involved both toes. For a curly fifth toe, these values were 25.0%, 16.7% and 58.3%, respectively. There was no associated structural anomaly, chromosomal abnormality, or syndrome in any case. Sixteen of the 38 curly toes were detected on prenatal ultrasound, including 13 of 26 with the fourth toe being curly and three of 12 with the fifth being curly.ConclusionsCongenital curly toe is not an uncommon condition, and can be detected on the prenatal ultrasound. Although it usually appears as an isolated finding without clinical significance, thorough ultrasound examination of the fetus should be recommended. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Adaptive control of heterogeneous ad hoc networks
Authors: Kulkarni S. S. , Dattatreya G. R. , Martinez H. , Soto R. 
Published: August 2004

AbstractHeterogeneous ad hoc networks are proposed as a solution to the scalability problem in pure ad hoc networks. Some of the links in heterogeneous networks have a much longer wireless transmission range (in one or more of their channels) than the other links. We study simple approaches for adaptive operation and performance optimization of such networks. Our study includes the following: (a) Use of very simple functions of observed performance for adaptive control; (b) Accommodation of an operational constraint imposed by a higher layer in the network. In this case, traffic from a forwarding node to a neighboring node, meant for an eventual destination, can be multiplexed over either long range links or over short range links but not both; (c) Route selection using extremely simple, predetermined criteria; (d) Performance comparison of the above three simplified approaches to the original algorithm of Reference [4]. The original algorithm is computationally more accurate, but handicapped by the absence of long range links.Our approaches are illustrated with simulation experiments on heterogeneous ad hoc networks fielding synthetic self‐similar (bursty) traffic. The performance comparisons of the approaches are presented for both fixed as well as dynamic network topologies. They emphasize the advantage of heterogeneous network operation over a pure ad hoc network, all nodes in the latter being functionally identical. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of Pure Cementitious Phases by Sol‐Gel Process as Precursor
Authors: Stephan Dietmar , Wilhelm Patrick 
Published: August 2004

AbstractCalcium silicates and aluminates are the main constituents of ordinary Portland cement (OPC) and calcium aluminate cements (CAC) and therefore the pure phases are of great importance for the investigation of interactions between binder and additives or admixtures. Additionally, investigations on clinker phases doped with foreign ions enable the improvement of the performance of cements. For this purpose great amounts of pure phases are needed. These phases are hard to synthesize via a solid state reaction of solid educts. Thus there is a need for a new, more efficient route to synthesize these phases. The sol‐gel process as precursor provides an alternative to the conventional method. In this paper experimental evidence is presented for an improved synthesis of calcium silicates and aluminates via sol‐gel processes, the characterisation of these clinker phases and their hydration behaviour.
Synthesis and Structure of the new Fluoride Bromide Ba6.668(2)Ca0.332(2)F12Br2 and Solid Solutions with Composition Ba7−xCaxF12(ClyBr1−y)2 with x = ∼0.5, 0 < y < 1
Authors: Frühmann B. , Kubel F. , Hagemann H. , Bill H. 
Published: August 2004

AbstractCrystals of the chemical composition Ba7F12Cl2 were modified by adding a small amount of Ca2+ to allow the synthesis of the corresponding bromine compound Ba[Ca]7F12Br2. These samples were prepared in a NaBr flux and characterized by single crystal x‐ray diffraction. The new structure crystallizes in a disordered arrangement in the hexagonal space group P63/m (176). The calcium ion has a coordination number of 6.Solid solutions on the heavy halide position can be synthesised in a NaCl/NaBr flux to obtain the compounds Ba7−xCaxF12(ClyBr1−y)2 with x = ∼0.5 and 0 < y < 1.Regardless the amount of calcium used in the preparation process, the Ca stoichiometry in the compound is always between 0.3 and 0.5. The lattice parameters differ depending on the Ca‐ and Br‐content between 1053.81(5) ⩽ a = b ⩽ 1058.93(3) pm and 421.21 ⩽ c ⩽ 426.78(3) pm.
Investigation of Structural Relationships between Racemic Alkali and Ammonium Hydrogen Tartrates and their Chiral Counterparts
Authors: Gelbrich Thomas , Threlfall Terence L. , Huth Susanne , Seeger Eva , Hursthouse Michael B. 
Published: August 2004

AbstractSingle crystals of racemic anhydrous alkali and ammonium hydrogen tartrates of the composition M(C4H5O6) with M = K, Rb, Cs, NH4 as well as MxM′1−x(C4H5O6) with {M = K, M′ = Rb, x = 0.5}, {M = K, M′ = NH4, x = 0.56} and {M = Rb, M′ = NH4, x = 0.61} were obtained from the reaction of D,L‐tartaric acid with the corresponding hydroxides MOH and / or M′OH. These compounds form an isostructural series (monoclinic, P21/c, Z = 4). The structures consist of alternating tartrate anion layers and cation layers. Each tartrate layer is held together by a number of hydrogen bonds and contains exclusively either the D or the L‐form of the tartrate. Structural analogies between these crystals and their chiral counterparts are investigated. The smilarity of cell parameters between racemic and chiral structures is shown to be a consequence of certain packing features that occur in both groups.