bluuebunny/crossref_metadata_2025_split huggingface dataset:
Huygens' principle in the transmission line matrix method (TLM). Local theory
Authors: Enders Peter , Vanneste Christian 
Published: March 2003

AbstractHuygens' principle (HP) is a well‐known fundamental principle of wave propagation. More generally, it can be understood as representing the principle of action‐by‐proximity (cf. Faraday's field theory etc.) and the superposition of secondary wavelets re‐irradiated at each point of the wavefront (Huygens' construction). These wavelets are isotropic in free space and in isotropic materials. We will show, that HP is realized within the transmission line matrix method (TLM) for scalar fields in free space of any dimension, if one considers only the scattered fields to represent the secondary wavelets. This corrects and generalizes the previous result for the total field in 2D. This property of TLM provides another explanation for its wide range of applicability. Copyright © 2003 John Wiley & Sons, Ltd.
Lithium inhibits Aβ‐induced stress in endoplasmic reticulum of rabbit hippocampus but does not prevent oxidative damage and tau phosphorylation
Authors: Ghribi Othman , Herman Mary M. , Savory John 
Published: March 2003

AbstractThe goal of this study was to assess the in vivo effect of Aβ on apoptosis pathways involving the endoplasmic reticulum and mitochondria, and its relationship to the induction of tau phosphorylation and DNA oxidative damage. In rabbits treated intracisternally with aggregated Aβ(1–42), clear evidence of endoplasmic reticulum stress was observed by the activation of caspase‐12 and cleavage of caspase‐3 in the endoplasmic reticulum. Mitochondrial injury was evident from the release of cytochrome c into the cytosol and the induction of oxidized mitochondrial DNA. Tau phosphorylation and nuclear translocation of NF‐κB and GSK‐3β were also observed. Treatment with lithium, an inhibitor of GSK‐3β, inhibited caspase activation but did not prevent mitochondrial DNA damage or tau hyperphosphorylation, suggesting that the translocation of GSK‐3β may represent an upstream event that leads to caspase activation but is unrelated to tau hyperphosphorylation or mitochondrial DNA oxidative damage. We propose that treatment by lithium alone is not sufficient to protect against the multiple adverse effects of Aβ, and the use of agents that prevent oxidative DNA damage and tau hyperphosphorylation, together with lithium, may provide better protection from the neurotoxic effect of Aβ. © 2003 Wiley‐Liss, Inc.
Preservation potential for Late Quaternary river alluvium
Authors: Lewin John , Macklin Mark G. 
Published: March 2003

AbstractValley sequences of Late Quaternary alluvial units reflect alluvial preservation as well as alluvial production factors. Effects of lateral channel migration, incision, aggradation and channel stability on preservation potential are explored and then considered in the light of 14 available data sets: cartographically dated and model data based on lateral channel migration; well‐mapped and dated Late Quaternary valley unit surveys; and composite age–frequency plots for dated alluvial units and flood sediments.Despite much expectable variation between sites, and the complex effects of river‐activity combinations, a common characteristic of the data sets examined is the significance of preservation factors. Lateral migration tends to eliminate older units as it creates new alluvial deposits, whereas incision may lead to the preferential preservation of older units beyond the incision slot. Aggradational environments are likely to preserve more complete records, although simultaneous lateral migration may eliminate, possibly repeatedly, the upper parts of alluvial units. The common pattern of inset and incised streams within Pleistocene and early Holocene fills or bedrock gives finite extent to later units within narrowing valleys so that development of new valley‐floor units is necessarily at the expense of reprocessing earlier ones. Floods associated with both slack water deposits and berms are also responsible for the removal of accessible earlier materials, thus limiting the preserved record of earlier events.In light of these censoring effects of river activities, the sequence of preserved Late Quaternary units within UK sequences is reconsidered. It is concluded that preservation potential factors have led to spatial and temporal bias in the alluvial record, and that both here and elsewhere preservation potential needs to be considered systematically alongside variable sedimentation resulting from allogenic environmental factors when interpreting the alluvial archive. Copyright © 2003 John Wiley & Sons, Ltd.
Backpackers in the Northern Territory of Australia—motives, behaviours and satisfactions
Authors: Mohsin Asad , Ryan Chris 
Published: March 2003

AbstractThis paper reports the findings of a study of 475 backpackers in the Northern Territory of Australia. It finds that backpackers tend to visit many of the same locations as other tourists, and like those tourists, are attracted to the natural sights of the Territory. It is also found that the backpackers can be divided into various groups. For example, of this sample about one‐third had left their previous career to travel, and about 12% had just completed studies. On the other hand about one‐quarter were holidaying during periods of normal paid holiday leave. It is argued that the market is not solely comprised of ‘life change’ or rite de passage holidaymakers. Additionally, differences are found between national groupings. Copyright © 2003 John Wiley & Sons, Ltd.
Kinetics and mechanism for the CH2O + NO2 reaction: A computational study
Authors: Xu Z. F. , Lin M. C. 
Published: March 2003

AbstractThe reactants, products, and transition states of the CH2O + NO2 reaction on the ground electronic potential energy surface have been searched at both B3LYP/6−311+G(d,p) and MPW1PW91/6−311+G(3df,2p) levels of theory. The forward and reverse barriers are further improved by a modified Gaussian‐2 method. The theoretical rate constants for the two most favorable reaction channels 1 and 2 producing CHO + cis‐HONO and CHO + HNO2, respectively, have been calculated over the temperature range from 200 to 3000 K using the conventional and variational transition‐state theory with quantum‐mechanical tunneling corrections. The former product channel was found to be dominant below 1500 K, above which the latter becomes competitive. The predicted total rate constants for these two product channels can be presented by kt (T) = 8.35 × 10−11 T6.68 exp(−4182/T) cm3/(mol s). The predicted values, which include the significant effect of small curvature tunneling corrections, are in quantitative agreement with the available experimental data throughout the temperature range studied (390–1650 K). © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 184–190, 2003
Preservativity logic: An analogue of interpretability logic for constructive theories
Authors: Iemhoff Rosalie 
Published: March 2003

AbstractIn this paper we study the modal behavior of Σ‐preservativity, an extension of provability which is equivalent to interpretability for classical superarithmetical theories. We explain the connection between the principles of this logic and some well‐known properties of HA, like the disjunction property and its admissible rules. We show that the intuitionistic modal logic given by the preservativity principles of HA known so far, is complete with respect to a certain class of frames.
DMAP/Cr(III) Catalyst Ratio: The Decisive Factor for Poly(propylene carbonate) Formation in the Coupling of CO2 and Propylene Oxide
Authors: Eberhardt Robert , Allmendinger Markus , Rieger Bernhard 
Published: March 2003

AbstractHighly efficient formation of poly(propylene carbonate) can be achieved in the coupling of CO2 and propylene oxide assisted by 4‐(N,N‐dimethylamino)pyridine (DMAP) and catalyzed with salen chromium(III) chloride by using DMAP/Cr ratios of less than 2. Under these conditions a possible backbiting mechanism is suppressed, leading to only minor amounts of cyclic carbonate as a side product.
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Dual Self‐Assembling Polycondensation of p‐Acetoxybenzoic Acid and p‐Acetamidobenzoic Acid
Authors: Kimura Kunio , Kobashi Kazufumi , Maeda Hitoshi , Yamashita Yuhiko 
Published: March 2003

AbstractThe dual self‐assembling polycondensation of p‐acetoxybenzoic acid (ABA) and p‐acetamidobenzoic acid in Therm S 800 was examined at 300 °C. Needle‐like crystals and lath‐like crystals were formed simultaneously through reaction‐induced crystallization of oligomers at a molar ratio of 30–50 mol‐% ABA in the feed. The needle‐like crystals comprised more p‐oxybenzoyl units, whereas the lath‐like ones contained higher amounts of p‐benzamide moieties.
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Decreased striatal dopamine transporter binding in a patient with extrapontine myelinolysis
Authors: Kim Joong‐Seok , Lee Kwang‐Soo , Han Si‐Ryung , Chung Yong‐An 
Published: March 2003

AbstractWe describe the case of a 61‐year‐old woman who developed extrapontine myelinolysis (EPM) with parkinsonism. Decreased striatal dopamine transporter binding assessed by [123I]N‐(3‐iodopropen‐2‐yl)‐2β‐carbomethoxy‐3β‐(4‐chlorophenyl) tropane and single photon emission computed tomography ([123I]IPT) SPECT) were observed in the patient, suggesting that osmotic injury causes the demyelination of nigrostriatal dopaminergic neurons and that such injury may be involved in the pathogenesis of EPM with parkinsonism.
Burden of parkinsonism: A population‐based study
Authors: Guttman Mark , Slaughter Pamela M. , Theriault Marc‐Erick , DeBoer Donald P. , Naylor C. David 
Published: March 2003

AbstractParkinson's disease (PD) is associated with a significant burden of illness and cost to society, which has been difficult to quantify. Our objective was to use linked administrative databases from the population of Ontario, Canada, to assess the prevalence of parkinsonism, physician‐ and drug‐related costs, and hospital utilization for parkinsonian patients compared with age/sex matched controls. An inception cohort of parkinsonian cases from 1993/1994 was age and sex matched (1:2) to controls and followed for 6 years. Patients were identified by the diagnostic code for PD, the use of specific PD drugs, or a combination. The parkinsonian case cohort (15,304) was matched to (30,608) controls that did not have parkinsonism. The age‐adjusted prevalence rates were 3.63 for men and for 3.24 women per 1,000 (increased by 5.4% for men and 9.8% for women). Physician costs were 1.4 times more, there were 1.44 times more hospital admissions, admissions were on average 1.19 times longer, and drug costs were 3.0 times more for parkinsonian cases. We conclude that the substantially higher physician and drug costs as well as hospitalization rates compared with controls clearly suggest that parkinsonism is associated with large direct costs to society. © 2002 Movement Disorder Society
Pallidotomy in Parkinson's disease improves single‐joint, repetitive, ballistic movements, but fails to modify multijoint, repetitive, gestural movements
Authors: Merello Marcelo , Balej Jorge , Leiguarda Ramon 
Published: March 2003

AbstractWe studied 12 non‐demented PD patients in on state before and 3 months after posteroventral pallidotomy (PVP), in order to evaluate the effects of surgery upon an unconstrained, multijoint skilled movement as well as a single joint, repetitive, ballistic movement. A Selspot II System was used for three‐dimensional data acquisition, processing and reconstruction of limb trajectories. Specific wrist kinematic features of spatial accuracy (linearity and planarity), temporal attributes (acceleration and velocity), spatiotemporal relationships (velocity‐curvature coupling), and joint kinematic variables (relationships between wrist and elbow velocities and relative arm angle amplitudes) for each cycle of movement were graphically and numerically analysed. QMC was applied to single joint, repetitive, ballistic movements. QMC significantly improved after PVP (P < 0.0006). However, wrist as well as joint kinematic variables of the gestural movements failed to change significantly after PVP. The lack of improvement of the kinematic abnormalities of the gestural movement in PD patients would indicate that they are unrelated to the basic motor deficit; most likely they are the result of a disruption of a complex of sensorimotor integration processes due to abnormal parieto‐frontal basal ganglia interaction. © 2002 Movement Disorder Society
Effects of dopaminergic cell degeneration on electrophysiological characteristics and GAD65/GAD67 expression in the substantia nigra: Different action on GABA cell subpopulations
Authors: Díaz Manuel Rodríguez , Barroso‐Chinea Pedro , Acevedo Abraham , González‐Hernández Tomás 
Published: March 2003

AbstractThe motor disturbances occurring in Parkinson's disease have been partially attributed to a hyperactivity of γ‐aminobutyric acid (GABA) ‐ergic nigral cells largely in the substantia nigra pars reticulata (SNr) secondary to the degeneration of dopaminergic nigrostriatal neurons. However, some aspects of this response remain unclear. In this work, different electrophysiological and neurochemical parameters were studied in GABAergic cells of the SN after unilateral nigrostriatal dopaminergic lesion using 6‐hydroxydopamine injection in rats. Our data showed that 1) the SN under normal conditions contains different subsets of GABAergic cells according to their firing pattern and glutamic acid decarboxylase mRNA levels, and 2) the response of these GABAergic cell subgroups was different after the ipsi‐ and contralateral dopaminergic cell degeneration. These findings indicate a complex regulation of nigral GABAergic activity after nigrostriatal dopaminergic degeneration that probably involves local mechanisms, the nigro‐striato‐nigral loop, as well as interhemispheric mechanisms whose anatomical basis remains unstudied. © 2002 Movement Disorder Society
Reliability of reported age at onset for Parkinson's disease
Authors: Reider Carson R. , Halter Cheryl A. , Castelluccio Peter F. , Oakes David , Nichols William C. , Foroud Tatiana ,   and the Parkinson Study Group
Published: March 2003

AbstractAn individual's age at onset of Parkinson disease (PD) can be collected through a variety of sources, including medical records, family report, and clinical observation. The most common source of PD age at onset information in the research setting is family‐report, which is then typically used to classify a subject as juvenile, young, or late age at onset. The reliability of the family‐reported age at onset of PD has not been rigorously examined. The present study used data from individuals diagnosed with PD to evaluate the reliability of age at onset information by comparing data obtained from three sources: 1) the subject's medical records, 2) a Family History Questionnaire, and 3) a Subject History Questionnaire. Among the 149 subjects with data for all three age at onset sources, the estimated reliability was R = 0.94. Similar reliability was observed when the sample was stratified based on gender, age at examination, disease duration, first symptom of PD, and years of education. The three measures of age at onset of PD show excellent agreement, strengthening confidence in the reliability of the reported age of clinical onset for PD. © 2002 Movement Disorder Society
An adaptive non‐conforming finite‐element method for Reissner–Mindlin plates
Authors: Carstensen Carsten , Weinberg Kerstin 
Published: March 2003

AbstractAdaptive algorithms are important tools for efficient finite‐element mesh design. In this paper, an error controlled adaptive mesh‐refining algorithm is proposed for a non‐conforming low‐order finite‐element method for the Reissner–Mindlin plate model. The algorithm is controlled by a reliable and efficient residual‐based a posteriori error estimate, which is robust with respect to the plate's thickness. Numerical evidence for this and the efficiency of the new algorithm is provided in the sense that non‐optimal convergence rates are optimally improved in our numerical experiments. Copyright © 2003 John Wiley & Sons, Ltd.
Brittle fracture in polycrystalline microstructures with the extended finite element method
Authors: Sukumar N. , Srolovitz D. J. , Baker T. J. , Prévost J.‐H. 
Published: March 2003

AbstractA two‐dimensional numerical model of microstructural effects in brittle fracture is presented, with an aim towards the understanding of toughening mechanisms in polycrystalline materials such as ceramics. Quasi‐static crack propagation is modelled using the extended finite element method (X‐FEM) and microstructures are simulated within the framework of the Potts model for grain growth. In the X‐FEM, a discontinuous function and the two‐dimensional asymptotic crack‐tip displacement fields are added to the finite element approximation to account for the crack using the notion of partition of unity. This enables the domain to be modelled by finite elements with no explicit meshing of the crack surfaces. Hence, crack propagation can be simulated without any user‐intervention or the need to remesh as the crack advances. The microstructural calculations are carried out on a regular lattice using a kinetic Monte Carlo algorithm for grain growth. We present a novel constrained Delaunay triangulation algorithm with grain boundary smoothing to create a finite element mesh of the microstructure. The fracture properties of the microstructure are characterized by assuming that the critical fracture energy of the grain boundary (Gcgb) is different from that of the grain interior (Gci). Numerical crack propagation simulations for varying toughness ratios Gcgb/Gci are presented, to study the transition from the intergranular to the transgranular mode of crack growth. This study has demonstrated the capability of modelling crack propagation through a material microstructure within a finite element framework, which opens‐up exciting possibilities for the fracture analysis of functionally graded material systems. Copyright © 2003 John Wiley & Sons, Ltd.
Nonprofit organization financial performance measurement: An evaluation of new and existing financial performance measures
Authors: Ritchie William J. , Kolodinsky Robert W. 
Published: March 2003

AbstractConsensus about financial performance measurement remains elusive for nonprofit organization (NPO)
researchers and practitioners alike, due in part to an overall lack of empirical tests of existing and new
measures. The purpose of the current study was to explore potential similarities of financial performance measures
derived from two sources: current NPO research and key informant interviews with NPO foundation constituencies. The
authors examined financial performance measurement ratios with data from fifteen Internal Revenue Service
(IRS) Form 990 line items. Using factor analytic techniques, they found three performance factors, each
with two associated financial measurement ratios, to be present. They categorized the performance factors as
fundraising efficiency, public support, and fiscal performance. This article discusses implications of the findings
and future research.
Efffects of vigabatrin on spontaneous locomotor activity of rats
Authors: Bouwman Brigitte M. , van Rijn Clementina M. , Willems‐van Bree Elly , Coenen Anton M.L. 
Published: March 2003

AbstractEffects of vigibatrin (saline, 125, 250, or 500 mg/kg i.p.) on spontaneous locomotor activity in Wistar rats were investigated. There was a dose dependent decrease in amount of locomotion for doses up to 250 mg/kg. This decrease was measurable 2–4 hours after injection and still became more pronounced in the following hours. The mean velocity during the movements 2–6 hours after injection remained intact and was higher in the 500 mg/kg group. In this high dose group an abnormal posture with a hunched back and pilo‐erection was observed. The decrease of the amount of motor activity with the preservation of the mean velocity in this non‐stimulating procedure, suggests that the level in which the experimental procedure imposes motor activity might be an important factor when measuring effects of vigabatrin. Postscript: Immediate post injection effects were observed, equivalent to those seen in the writhing test, a pain test using hyperosmolar saline injections. These observations stress the importance of controlling the osmolarity of the injection fluids.
Expression of the developmental Sonic hedgehog (Shh) signalling pathway is up‐regulated in chronic lung fibrosis and the Shh receptor patched 1 is present in circulating T lymphocytes
Authors: Stewart Gareth A , Hoyne Gerard F , Ahmad Sharon A , Jarman Elizabeth , Wallace William AH , Harrison David J , Haslett Christopher , Lamb Jonathan R , Howie Sarah EM 
Published: March 2003

AbstractDuring pulmonary development, Sonic hedgehog (Shh) and transforming growth factor β1 (TGF‐β1) signalling both contribute to branching morphogenesis. In interstitial lung disease, the complex alveolar structure of the lung is disrupted and remodelled, which leads to fibrosis, loss of respiratory surface, morbidity, and mortality. It is well documented that TGF‐β1 is involved in fibrosis. However, little is known about Shh signalling in damaged epithelia. This study examined whether or not components of the Shh signalling pathway, as well as TGF‐β1, are expressed in human fibrotic lung disease (cryptogenic fibrosing alveolitis and bronchiectasis) and in murine experimental models of fibrotic and non‐fibrotic chronic pulmonary inflammation. Using immunohistochemistry, it was observed that Shh, like TGF‐β1, is up‐regulated in epithelial cells at sites of fibrotic disease but not non‐fibrotic inflammation. The Shh receptor patched was detected in infiltrating mononuclear cells and alveolar macrophages, as well as normal resting peripheral blood T lymphocytes. Neither Shh nor patched is expressed by hyperproliferative goblet cells in inflammatory epithelium. This study demonstrates that patched is present in human peripheral CD4 and CD8 lymphocytes at both protein and mRNA levels. Taken together, these results suggest that components of the highly conserved Shh signalling pathway may play a role in the remodelling of damaged pulmonary epithelium and that damaged epithelium and cells of the immune system may communicate via this pathway. Copyright © 2003 John Wiley & Sons, Ltd.
Maspin expression in invasive breast cancer: association with other prognostic factors
Authors: Mohsin Syed K , Zhang Ming , Clark Gary M , Craig Allred D 
Published: March 2003

AbstractMaspin is a unique serine protease inhibitor with a molecular weight of 42 kDa. It has been shown to inhibit tumour cell motility and invasion in cell culture, and tumour growth and metastasis in animal models. There is very limited data on the prognostic utility of maspin in human breast cancer. We performed a preliminary study to assess the associations of maspin with other established prognostic factors in invasive breast cancer (IBC). 1068 paraffin‐embedded IBCs were immunohistochemically stained with a monoclonal antibody to maspin. A nuclear signal was present in 96% and a cytoplasmic signal in 35% of the cases. Nuclear staining was related to oestrogen (ER) and progesterone receptor (PR) positivity (p < 0.0001), but not to S‐phase fraction (SPF) or ploidy. Cytoplasmic staining was related to ER and PR negativity (p < 0.0001), high SPF (p < 0.0001), and aneuploidy (p = 0.003). Thus, maspin nuclear staining was significantly associated with good prognostic factors, while cytoplasmic staining was associated with poor prognostic markers. These findings suggest that the presence of maspin in two different compartments of the cell may have different biological and clinical implications. Additional studies are needed to evaluate further this expression profile of maspin in breast cancer. Copyright © 2003 John Wiley & Sons, Ltd.