bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical utility of the polymerase chain reaction in the diagnosis of extrapulmonary tuberculosis
Authors: Kolk AH , Kox LF , van Leeuwen J , Kuijper S , Jansen HM
Published: November 2002

This study examines the diagnostic utility of the polymerase chain reaction (PCR) in 156 patients (five human immunodeficiency virus (HIV) seropositive) suspected of extrapulmonary tuberculosis. The results of PCR in 226 samples from 11 different sites were compared with the results of microscopy and culture. Positive culture results were predicted in 86% of samples by PCR but in only 31% by microscopy. Specificity of PCR was 92%. In cases with culture-proven tuberculosis, PCR identified all 11 microscopy positive cases and 19 of 24 (79%) of the microscopy-negative cases. In four patients, PCR excluded the diagnosis of tuberculosis in microscopy-positive samples, which were later shown to contain mycobacteria other than Mycobacterium tuberculosis or laboratory contaminants. In 20 patients (microscopy, PCR and culture negative) a trial of antituberculous drugs was given, but patients showed no improvement and treatment was stopped. In 17 patients, all culture negative (in nine PCR was positive, three of whom also had positive microscopy) the diagnosis was probable tuberculosis based on clinical findings and response to treatment. This polymerase chain reaction has a much higher sensitivity than microscopy and can facilitate therapeutic decisions for those with suspected extrapulmonary tuberculosis.
Analysis of BAL fluid in M. avium-intracellulare infection in individuals without predisposing lung disease
Authors: Yamazaki Y , Kubo K , Sekiguchi M , Honda T
Published: November 2002

The purpose of this study was to investigate the characteristics of pulmonary inflammation caused by Mycobacterium avium-intracellulare (MAI) in individuals with neither predisposing lung disease nor immunodeficiency. We reviewed the records of 20 patients with pulmonary MAI infection (including 19 female patients) whose past history and previous chest radiographs revealed no predisposing lung disease. We analysed the bronchoalveolar lavage fluid (BALF) from these 20 patients and from six normal female controls. The BALF was recovered directly from the relevant segment that was identified with chest-computed tomography. The BALF cell profiles showed significantly elevated counts for total cells, lymphocytes and neutrophils, but the macrophage cell count was not elevated. The CD4+ lymphocyte count and CD4+/CD8+ ratio were significantly increased compared with those in the controls. The lymphocytes demonstrated phenotypical evidence of activation, with increased expression of human leukocyte antigen-D-related antigen (HLA-DR). The tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6 and IL-8 concentrations were significantly increased. The neutrophil elastase concentration was also increased, and it was significantly correlated with the neutrophil cell count in the BALF. These findings suggest that the increased counts of activated CD4+ lymphocytes and neutrophils and the elevated concentrations of proinflammatory cytokines and neutrophil elastase appear to be common characteristics in Mycobacterium avium-intracellulare infection.
Effects of air quality on chronic respiratory symptoms adjusted for allergy among preadolescent children
Authors: Jedrychowski W , Flak E
Published: November 2002

The aim of this study was to assess the respiratory effects of outdoor air pollution after correcting for allergy and indoor air quality. The respiratory health survey targeted 1,129 schoolchildren, 9 yrs of age, attending schools in Krakow located in city areas differing in outdoor air pollution levels. Chronic phlegm as a unique symptom was related neither to allergy nor to indoor variables, but was associated with the outdoor air pollution level (odds ratio (OR): 4.2; 95% confidence interval (CI): 1.1-16.9). The same relationship has been confirmed for the self-reported local sources of industrial air pollution in the area of residence (OR: 4.2; 95% CI: 1.5-11.7). Hay fever appeared to be related to outdoor air pollution level (OR: 1.43; 95% CI: 1.1-2.0) and self-reported heavy traffic (OR: 1.3; 95% CI: 1.0-1.7). In the total sample, wheezing was connected exclusively to allergy and parental atopy, while attacks of dyspnoea with wheezing and asthma diagnosed by physician only were associated with allergy. Since the effect of outdoor pollutants on chronic cough and wheezing (odds ratio: 1.85; 95% confidence interval: 1.03-3.33) was only shown to be significant in the subsample of children without allergy and parental atopy, it may be postulated that either allergy is predisposing to respiratory reactions, or outdoor air pollution is coinvolved in an allergization process of the preadolescent children. Consequently, allergy should be considered as an important confound in epidemiological studies on the respiratory effects of air pollution.
Airway response of children with primary ciliary dyskinesia to exercise and beta2-agonist challenge
Authors: Phillips GE , Thomas S , Heather S , Bush A
Published: November 2002

In primary ciliary dyskinesia (PCD), chest physiotherapy for airway clearance is essential. Exercise and inhaled beta2-agonists can produce bronchodilation thereby augmenting physiotherapy. However, both can also cause bronchoconstriction, and the effects of these stimuli in PCD are not known. In a preliminary study, the mean coefficients of variation for forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) in children with PCD were determined. They were 5.4%, 4.4% and 8.4%, respectively. Twelve children with PCD and 12 normal children performed pulmonary functions under resting conditions; during and after a validated treadmill exercise test; and before and 15 min after 200 microg of inhaled salbutamol. At baseline, FEV1, FVC, forced mid-expiratory flow (FEF25-75%) and PEFR were significantly reduced in the PCD group compared with the control group. Exercise produced a significant increase in PEFR in the PCD group. There was no significant difference between the groups in response to salbutamol. Within the PCD group, exercise produced a significantly greater increase in PEFR than beta2-agonist therapy. In conclusion, in children with primary ciliary dyskinesia there is evidence of obstructive pulmonary disease. In these children, exercise is a more potent stimulus for bronchodilation than by inhaled beta2-agonists. Enhancement of airway clearance may best be achieved by encouraging patients to exercise before physiotherapy rather than by inhaling beta2-agonists, but the effects of each should be assessed for each individual before instigating treatment.
The Phospholipids Sphingosine-1-Phosphate and Lysophosphatidic Acid Prevent Apoptosis in Osteoblastic Cells via a Signaling Pathway Involving Gi Proteins and Phosphatidylinositol-3 Kinase
Authors: Grey Andrew , Chen Qi , Callon Karen , Xu Xin , Reid Ian R. , Cornish Jill
Published: November 2002

The naturally occurring phospholipids lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) have recently emerged as bioactive compounds that exert mitogenic effects in many cell types, including osteoblasts. In the current study, we examined the ability of each of these compounds to influence osteoblast survival. Using terminal deoxynucleotidyl transferase-mediated deoxyuridine 5′-triphosphate nick-end labeling and DNA fragmentation assays, we found that both LPA and S1P dose-dependently inhibited (by at least 50% and 40%, respectively) the apoptosis induced by serum withdrawal in cultures of primary calvarial rat osteoblasts and SaOS-2 cells. The antiapoptotic effects were inhibited by pertussis toxin, wortmannin, and LY294002, implicating Gi proteins and phosphatidylinositol-3 kinase (PI-3 kinase) in the signaling pathway that mediates phospholipid-induced osteoblast survival. Specific inhibitors of p42/44 MAPK signaling did not block LPA- or S1P-induced osteoblast survival. LPA and S1P induced PI-3 kinase-dependent activation of p70 S6 kinase, but rapamycin, a specific inhibitor of p70 S6 kinase activation, did not prevent phospholipid-induced osteoblast survival. LPA and S1P also inhibited apoptosis in Swiss 3T3 fibroblastic cells in a Gi protein-dependent fashion. In fibroblastic cells, however, the antiapoptotic effects of S1P were sensitive to inhibition of both PI-3 kinase and p42/44 MAPK signaling, whereas those of LPA were partially abrogated by inhibitors of p42/44 MAPK signaling but not by PI-3 kinase inhibitors. These data demonstrate that LPA and S1P potently promote osteoblast survival in vitro, and that cell-type specificity exists in the antiapoptotic signaling pathways activated by phospholipids.
Insulin Inhibits Dexamethasone Effect on Angiotensinogen Gene Expression and Induction of Hypertrophy in Rat Kidney Proximal Tubular Cells in High Glucose
Authors: Zhang Shao-Ling , Chen Xing , Wei Chih-Chang , Filep Janos G. , Tang Shiow-Shih , Ingelfinger Julie R. , Chan John S. D.
Published: November 2002

The present studies investigated whether insulin inhibits the stimulatory effect of dexamethasone (DEX) on angiotensinogen (ANG) gene expression and induction of hypertrophy in rat immortalized renal proximal tubular cells (IRPTCs) in a high-glucose milieu. Rat IRPTCs were cultured in monolayer. ANG and ANG mRNA expression in IRPTCs were quantified by a specific RIA for rat ANG and by RT-PCR assay, respectively. A fusion gene containing the full length of the 5′-flanking region of the rat ANG gene linked to a chloramphenicol acetyl transferase reporter gene was introduced into IRPTCs. The level of fusion gene expression was determined by cellular chloramphenicol acetyl transferase enzymatic activity. Cellular hypertrophy was assessed by flow cytometry, cellular p27Kip1 protein expression, and protein assay. Our results showed that high glucose (i.e. 25 mm) and DEX (10−7m) additively stimulated ANG gene expression and induced IRPTC hypertrophy. Insulin inhibited the effect of high glucose and DEX on these parameters. The inhibitory effect of insulin was reversed by PD 98059 (a MAPK inhibitor) but not by wortmannin (a phosphatidylinositol-3-kinase inhibitor). These results demonstrate that insulin is effective in blocking the stimulatory action of high glucose and DEX on ANG gene expression and induction of IRPTC hypertrophy, suggesting its important role in preventing local intrarenal renin-angiotensin system activation and renal proximal tubular cell hypertrophy induced by hyperglycemia and glucocorticoids in vivo.
A Novel Method for Growing Human Breast Epithelium in Vivo Using Mouse and Human Mammary Fibroblasts
Authors: Parmar Hema , Young Peter , Emerman Joanne T. , Neve Richard M. , Dairkee Shanaz , Cunha Gerald R.
Published: November 2002

A novel system is described for studying the growth of normal human mammary epithelium in vivo as grafts in athymic nude mice. The key feature of this model is reconstitution of the epithelial-stromal interactions required for normal growth and differentiation of the human mammary epithelium, which produces ducts that are comparable to those in the normal human mammary gland. Human breast epithelial organoids were combined with mammary fibroblasts from mouse or human origin in collagen gels, which were subsequently transplanted under the renal capsule of female nude mice hosts. The resulting grafts showed an increase in the ductal density compared with that observed previously. These ducts expressed appropriate markers for luminal and myoepithelial cells and steroid receptors. Treatment of the host with diethylstilbestrol or estradiol and progesterone significantly increased the number of ducts observed and increased cell proliferation. The grafts also displayed production of β-casein and milk fat globule membrane protein when the hosts were allowed to become pregnant. This model allows for a variety of epithelial and stromal cells to be used in combination, which would aid in understanding key factors that regulate normal human mammary gland development.
Neuropeptide Y1 and Y5 Receptors Mediate the Effects of Neuropeptide Y on the Hypothalamic-Pituitary-Thyroid Axis
Authors: Fekete Csaba , Sarkar Sumit , Rand William M. , Harney John W. , Emerson Charles H. , Bianco Antonio C. , Beck-Sickinger Annette , Lechan Ronald M.
Published: November 2002

Neuropeptide Y (NPY) is one of the most important hypothalamic-derived neuropeptides mediating the effects of leptin on energy homeostasis. Central administration of NPY not only markedly stimulates food intake, but simultaneously inhibits the hypothalamic-pituitary-thyroid axis (HPT axis), replicating the central hypothyroid state associated with fasting. To identify the specific NPY receptor subtypes involved in the action of NPY on the HPT axis, we studied the effects of the highly selective Y1 ([Phe7,Pro34]pNPY) and Y5 ([chicken pancreatic polypeptide1–7, NPY19–23, Ala31, Aib32 (aminoisobutyric acid), Q34]human pancreatic polypeptide) receptor agonists on circulating thyroid hormone levels and proTRH mRNA in hypophysiotropic neurons of the hypothalamic paraventricular nucleus. The peptides were administered continuously by osmotic minipump into the cerebrospinal fluid (CSF) over 3 d in ad libitum-fed animals and animals pair-fed to artificial CSF (aCSF)-infused controls. Both Y1 and Y5 receptor agonists nearly doubled food intake compared with that of control animals receiving aCSF, similar to the effect observed for NPY. NPY, Y1, and Y5 receptor agonist administration suppressed circulating levels of thyroid hormones (T3 and T4) and resulted in inappropriately normal or low TSH levels. These alterations were also associated with significant suppression of proTRH mRNA in the paraventricular nucleus, particularly in the Y1 receptor agonist-infused group [aCSF, NPY, Y1, and Y5 (density units ± sem), 97.2 ± 8.6, 39.6 ± 8.4, 19.9 ± 1.9, and 44.6 ± 8.4]. No significant differences in thyroid hormone levels, TSH, or proTRH mRNA were observed between the agonist-infused FSanimals eating ad libitum and the agonist-infused animals pair-fed with vehicle-treated controls. These data confirm the importance of both Y1 and Y5 receptors in the NPY-mediated increase in food consumption and demonstrate that both Y1 and Y5 receptors can mediate the inhibitory effects of NPY on the HPT axis.
Double Mutations in Klotho and Osteoprotegerin Gene Loci Rescued Osteopetrotic Phenotype
Authors: Yamashita Teruhito , Okada Seiji , Higashio Kanji , Nabeshima Yo-ichi , Noda Masaki
Published: November 2002

Klotho gene mutant mice (klotho mice, also called kl/kl) exhibit osteopetrosis in the metaphysis of femora and tibiae and die within 3 months. We previously showed by semiquantitative RT-PCR that osteoprotegerin (opg) expression levels in klotho mice were about 2-fold higher than those in wild-type mice in the bone marrow, spleen, and lung. To examine whether the high osteoprotegerin expression levels account for the osteopetrotic phenotype in the klotho homozygous mutant mice in vivo, we made double mutant mice by crossing klotho mutant and osteoprotegerin-deficient mice. Micro computed tomography analysis in the two-dimensional sagittal planes of the metaphyses and cross-sections of femoral midshaft revealed that the abnormally high fractional trabecular bone volume in klotho homozygous mice (kl/kl; 29.71%), which was about 4-fold higher compared with that of wild-type [klotho (+/+) opg (+/+)] mice (7.81%), was rescued by the coexistence of heterozygous mutation in opg gene locus (+/−; 8.36%). Single heterozygous mutation in the opg gene locus alone (without klotho mutation) did not show phenotype (trabecular bone volume, 5.84%; not significantly different from wild type). High levels of osteoprotegerin mRNA expression in the bone marrow in klotho mutant mice were reduced by the heterozygous mutation in the opg gene locus. Furthermore, high osteoprotegerin protein levels in klotho mutant mice were also reduced by the heterozygous mutations in opg gene locus. Thus, elevated levels of osteoprotegerin in mutant mice contribute at least in part to reveal the osteopetrotic phenotype in klotho mice.
A Questionnaire Survey of Complaints of Infrasound and Low-Frequency Noise
Authors: Møller Henrik , Lydolf Morten
Published: November 2002

A survey of complaints about infrasound and low frequency noise has been carried out. 198 persons reported their troubles in a questionnaire. Their verbal reports often described the sound as deep and humming or rumbling, as if coming from the distant idling engine of a truck or pump. Nearly all respondent's reported a sensory perception of a sound. In general they reported that they perceived the sound with their ears, but many mention also the perception of vibration, either in their body or in external objects. The sound disturbs and irritates during most activities, and many consider its mere presence as a torment to them. Many of the respondents reported secondary effects, such as insomnia, headache and palpitation, which they associtated with the sound mainly because it occured at the same place as the sound. In a majority of the cases, only one or a few persons can hear the sound, but there are also examples, where it is claimed to be audible to everybody. Typically, measurements have shown that existing limits (and hearing thresholds) are not exceeded. The investigation leaves the key question: Are the troubles induced by an external sound or not, and if they are, which frequencies and levels are involved? The feasibility of a study of this is supported by the results.
Perception of Low Frequency Vibrations by Heavy Vehicle Drivers
Authors: Hassan Rayya , McManus Kerry
Published: November 2002

A study was initiated to identify the levels and frequencies of heavy articulated vehicle body vibrations at which the drivers perceive the ride as uncomfortable. The study involved conducting a subjective assessment survey in which a panel of truck drivers were asked to rate the ride quality provided by a number of road sections with different surface roughness characteristics. The study's objective was achieved by correlating the mean panel ratings (MPRs) to road surface roughness contents in different one-third-octave bands of the roughness spectrum. The results showed that at 100 km/h, truck drivers object mainly to motions resulting from roughness excitations of the low frequency vibration modes of the truck body in the range 1.42 – 5.7 Hz. These results were validated by correlating MPRs with the levels of whole body vibrations measured on the driver's seat in a representative vehicle while traversing some test sections. MPRs were found to correlate well with the measured overall vibration total values and the likely comfort reactions to various magnitudes of overall vibration total values given by ISO 2631–1. The influence on MPRs of vehicle and driver related factors were also investigated and commented upon.
Vibrational Characteristics of Tractor Seat Cushion Materials and Ride Comfort
Authors: Mehta C. R. , Tewari V. K.
Published: November 2002

Tractor seat design can be used as a means to modify loads on body structures to reduce operator's discomfort. The overall comfort and performance of the tractor seating system consist oi fi-ame. cushion. covers. suspension and damping mechanisms. Vibration attenuation in a tractor seat is achieved by selecting the proper suspension and damping mechanism. The vibration characteristics of cushion materials are often overlooked. This paper describes a method of vibration characterisation of tractor seat cushion materials to improve operator's comfort. Nine commercially available seat cushion materials of different density, thickness and composition were randomly selected for this study. Transmissibility data were obtained by measuring input acceleration values on the base plate and output acceleration values at mass at different frequencies from 1 to 7 Hz. It was observed that vibration transmissibilities at resonance and the resonance frequency were significantly affected by the thickness of cushion materials. In the frequency range above the resonance, especially at frequencies higher than 5 Hz, the thinner sample had a higher transmissibility than the thicker sample. In contrast, over the frequency range below the resonance, especially at frequencies lower than 4 Hz, thicker samples had a higher transmissibility than the thinner samples. The synthetic rubber foam cushion materials 1.9D (thickness of 101 mm, density of 69.72 kg/m3) and D (thickness of 54 mm, density of 68.70 kg/m3) may be recommended for tractor seat pan and backrest cushion materials, respectively on the basis of vibration characteristics.
The Relationship between Vibratory Sensation and Body Surface Vibration Induced by Low-Frequency Noise
Authors: Takahashi Yukio , Kanada Kazuo , Yonekawa Yoshiharu
Published: November 2002

Human body surface vibration induced by low-frequency noise was measured at the forehead, the chest and the abdomen. At the same time, subjects rated their vibratory sensation at each of these locations. The relationship between the measured vibration on the body surface and the rated vibratory sensation was examined, revealing that the vibratory sensations perceived in the chest and abdomen correlated closely with the vibration acceleration levels of the body surface vibration. This suggested that a person exposed to low-frequency noise perceives vibration at the chest or abdomen by sensing the mechanical vibration that the noise induces in the body. At the head, on the other hand, it was found that the vibratory sensation correlated comparably with the vibration acceleration level of the body surface vibration and the sound pressure level of the noise stimulus. This finding suggested that the mechanism of perception of vibration in the head is different from that of the perception of vibratory sensation in the chest and the abdomen.
Wave — Jet Converters
Authors: Arabadzhi Vladimir V.
Published: November 2002

The possibilities of conversion of the energy of gravitational surface waves in liquid into a constant reactive flow due to special nonlinear mechanical floating devices (wave-jet converters) are investigated. The last ensure rectification of wave pressure and the effect of wave traction. Physical problems of radiation and scattering wave pressure rectification are considered separately using the examples of concrete devices. A ship model of special construction has been designed and tested. This model effectively converts ship's pitching immediately into a constant jet flow without using any external sources of energy. The ship's motion is characterized by an average Froude number Fr=0.14 and average forward velocity exceeding the velocities of liquid particles in the wave field. This ship presents a uniflow wave jet propulsive device.
A generalized multinomial discriminant procedure with applications
Authors: Mojirsheibani Majid
Published: November 2002

We propose a generalized multinomial discriminant procedure for classification on discrete spaces. Both the mechanics and the asymptotic optimality of the method are discussed. An application of the proposed procedure to combined classification, as well as the conditions under which the resulting combined classifier is asymptotically optimal, are also discussed. Copyright © 2002 John Wiley & Sons, Ltd.
The bivariate lognormal distribution for describing joint statistical properties of a multivariate storm event
Authors: Yue Sheng
Published: November 2002

The bivariate lognormal distribution is proposed as a model for the joint distribution of storm peak (maximum rainfall intensity) and storm amount. Using the marginal distributions, the joint distribution, the conditional distributions, and the associated return periods are derived. The model is found appropriate for representing multiple episodic storm events at the Motoyama meteorological observation station in Japan. Copyright © 2002 John Wiley & Sons, Ltd.
Statistical analysis of catalyst data
Authors: Hjorth Urban , Chan Albert , Zhao Dongmei , Ljungström Evert
Published: November 2002

Catalytic converters are crucial for the reduction of car emissions. The performance of aging catalysts in use has not been well known. Data on catalysts from scrapped cars of different ages has been taken in well controlled laboratory conditions. The statistical analysis of these data compares and uses different models of the regression type and also generalized regression for ordered categorical data. A significant, though not very dramatic, deterioration with age is shown for the catalytic converters. The overall impression is, however, that converters like those examined in this study do function reasonably well at least up to about 200000 km driving distances. Copyright © 2002 John Wiley & Sons, Ltd.
Magnitude–frequency relationship for debris flows on the fan of the Chalance torrent, Valgaudemar (French Alps)
Authors: Helsen M. M. , Koop P. J. M. , Van Steijn H.
Published: November 2002

In 1996 a large debris flow occurred on the fan of the Chalance torrent system, a tributary of the Séveraisse river, French Alps. To investigate the magnitude and frequency of such debris flows on this fan, fieldwork was carried out in the summer of 1998. Detailed investigation revealed that several debris flows have occurred in the past 200 years. Lichenometry was used as a dating technique to obtain the frequency of these debris‐flow events. Also the volume of these flows was estimated. With these data a magnitude–frequency relationship was constructed. This relationship shows a maximum magnitude of at least 50 × 103 m3. Based on data for the past c. 150 years, a debris flow of such a volume appears to have a recurrence interval of approximately 34 years. Copyright © 2002 John Wiley & Sons, Ltd.
Fire intensity, slopewash and bio‐transfer of sediment in eucalypt forest, Australia
Authors: Dragovich Deirdre , Morris Rowena
Published: November 2002

Sediment movement (slopewash and bio‐transfer), runoff, and organic matter movement (mainly leaf litter, ash and charcoal) were monitored on ten plots for a six‐month period following bushfires in eastern Australia in the 1990s. Plots were installed in areas which had experienced high, moderate and low intensity burns. Although between‐plot variability was high, slopewash and organic matter amounts were greatest on the intensely burnt areas, and progressively less on moderate and low intensity burns. In contrast, most leaf litter input from scorched leaf fall was derived from, and collected in, moderately burnt areas. Bio‐transfer of sediment (direct downslope surface movement produced by faunal activity) occurred mainly by ant mounding, and was more than ten times greater on moderately burnt areas than on plots having high or low intensity burns. Bio‐transfer accounted for approximately 36 per cent of total sediment collected, with this material being recorded least often and in smallest quantities on areas of high intensity burns. Bio‐transfer by ant mounding and animal scratchings contributed loose surface sediment for transport by overland flow, disproportionately increasing total sediment movement to plot aprons in areas of moderate intensity burns. Copyright © 2002 John Wiley & Sons, Ltd.
Three‐dimensional numerical modelling of free surface flows with non‐hydrostatic pressure
Authors: Koçyigit Musteyde B. , Falconer Roger A. , Lin Binliang
Published: November 2002

A three‐dimensional numerical model is developed for incompressible free surface flows. The model is based on the unsteady Reynolds‐averaged Navier–Stokes equations with a non‐hydrostatic pressure distribution being incorporated in the model. The governing equations are solved in the conventional sigma co‐ordinate system, with a semi‐implicit time discretization. A fractional step method is used to enable the pressure to be decomposed into its hydrostatic and hydrodynamic components. At every time step one five‐diagonal system of equations is solved to compute the water elevations and then the hydrodynamic pressure is determined from a pressure Poisson equation. The model is applied to three examples to simulate unsteady free surface flows where non‐hydrostatic pressures have a considerable effect on the velocity field. Emphasis is focused on applying the model to wave problems. Two of the examples are about modelling small amplitude waves where the hydrostatic approximation and long wave theory are not valid. The other example is the wind‐induced circulation in a closed basin. The numerical solutions are compared with the available analytical solutions for small amplitude wave theory and very good agreement is obtained. Copyright © 2002 John Wiley & Sons, Ltd.
Computational bifurcation and stability studies of the 8: 1 thermal cavity problem
Authors: Salinger Andrew G. , Lehoucq Richard B. , Pawlowski Roger P. , Shadid John N.
Published: November 2002

Stability analysis algorithms coupled with a robust Newton–Krylov steady‐state iterative solver are used to understand the behavior of the 2D model problem of thermal convection in a 8: 1 differentially heated cavity. Parameter continuation methods along with bifurcation and linear stability analysis are used to study transition from steady to transient flow as a function of Rayleigh number. To carry out this study the steady‐state form of the governing PDEs is discretized using a Galerkin/least‐squares finite element formulation, and solved on parallel computers using a fully coupled Newton method and preconditioned Krylov iterative linear solvers. Linear stability analysis employing a large‐scale eigenvalue capability is used to determine the stability of the steady solutions. The boundary between steady and time‐dependent flows is determined by a Hopf bifurcation tracking capability that is used to directly track the instability with respect to the aspect ratio of the system and with respect to mesh resolution. The effect of upwinding stabilization terms in the finite element formulation on the computed value of critical Rayleigh number is investigated. The Hopf bifurcation signaling the onset of flow is determined to occur at a critical Rayleigh number of Ra=3.0604×105. Copyright © 2002 John Wiley & Sons, Ltd.
Parallel computations of natural convection flow in a tall cavity using an explicit finite element method
Authors: Dunn Timothy A. , McCallen Rose C.
Published: November 2002

An explicit finite element method was used to predict a natural convection flow in an enclosed cavity. The problem considered was a differentially heated, tall (8:1), rectangular cavity with a Rayleigh number of 3.4 × 105 and Prandtl number of 0.71. The incompressible Navier–Stokes equations were solved using a Boussinesq approximation for the buoyancy force. The algorithm was developed for efficient use on massively parallel computer systems with emphasis on time‐accurate simulations. It was found that the average temperature and velocity values can be captured with a relatively coarse grid, while the oscillation amplitude and period appear to be grid sensitive and require a refined computation. Copyright © 2002 John Wiley & Sons, Ltd.
Application of the FIDAP code to the 8:1 thermal cavity problem
Authors: Gresho P. M. , Sutton S. B.
Published: November 2002

We present results using FIDAP on 3 meshes with 3 different elements (Q1Q0, Q2P‐1, Q2Q‐1) employed on each. Whereas the bulk of the results were obtained via the ‘classical’ Galerkin finite element method (GFEM) and the trapezoidal (TR) time integrator, we also tested several alternative options: flux‐conservative formulation, energy‐conservative formulation, streamline upwinding, mass lumping, backward Euler time stepping, and one additional element (Q2Q1). The most accurate of these options was the Q2Q‐1 element in the advective formulation, no upwinding, trapezoidal time integration, and consistent mass; i.e. straight GFEM. Copyright © 2002 John Wiley & Sons, Ltd.
Parenting and attachment among toddlers with congenital anomalies: Examining the Strange Situation and attachment Q‐sort
Authors: Clements Melissa , Barnett Douglas
Published: November 2002

This study assessed parent and child predictors of attachment in a sample of 72 toddlers with neurological (e.g., cerebral palsy) and non‐neurological (e.g., cleft lip and palate) birth defects and their mothers. Parenting quality (e.g., sensitivity) was expected to be more important in predicting the attachment relationship than type and severity of child medical condition. Parenting and indices of severity of child condition were measured via researcher observation. Attachment was measured via the Strange Situation and parent reported Attachment Q‐sort. Parenting quality was better for children with more severe appearance disfigurements. Strange Situation and Q‐sort assessments of attachment were not significantly related. Children with neurological impairments were at greater risk for developing insecure attachments than were children with non‐neurological conditions. Parenting quality also directly predicted Strange Situation assessed attachment security and Q‐sort comfort seeking/exploration but not standard Q‐sort criterion scores. Parenting quality partially mediated the relation between child medical condition and attachment security. Results suggest child medical factors influence parenting, and thereby, child attachment. ©2002 Michigan Association for Infant Mental Health.
Representation theory for classes of initial value problems with quaternionic analysis
Authors: Gürlebeck Klaus , Sprößig Wolfgang
Published: November 2002

We consider time‐dependent Stokes problems for the case of low Reynolds number in smoothly bounded domains. By using a finite difference time discretization, the problem is reduced to a sequence of steady‐state Stokes problems. These boundary value problems are solved by means of hypercomplex analysis. In the second part, we consider initial boundary value problems of the so‐called Galpern–Sobolev type. An implicit time discretization method is deduced. Making use of a modified Teodorescu transform and suitable quaternionic Hilbert space projections, we obtain a representation of the solution. Copyright © 2002 John Wiley & Sons, Ltd.
Complex‐distance potential theory, wave equations, and physical wavelets
Authors: Kaiser Gerald
Published: November 2002

Potential theory in ℝn is extended to ℂn by analytically continuing the Euclidean distance function. The extended Newtonian potential ϕ(z) is generated by a (non‐holomorphic) source distribution δ˜(z) extending the usual point source δ(x). With Minkowski space ℝn, 1 embedded in ℂn+1, the Laplacian Δn+1 restricts to the wave operator □n,1 in ℝn, 1. We show that δ˜(z) acts as a propagator generating solutions of the wave equation from their initial values, where the Cauchy data need not be assumed analytic. This generalizes an old result by Garabedian, who established a connection between solutions of the boundary‐value problem for Δn+1 and the initial‐value problem for □n,1 provided the boundary data extends holomorphically to the initial data. We relate these results to the physical avelets introduced previously. In the context of Clifford analysis, our methods can be used to extend the Borel–Pompeiu formula from ℝn+1 to ℂn+1, where its riction to Minkowski space ℝn, 1 provides solutions for time‐dependent Maxwell and Dirac equations. Copyright © 2002 John Wiley & Sons, Ltd.
Effects of conceptual assignments and conceptual change discussions on students' misconceptions and achievement regarding force and motion
Authors: Eryilmaz Ali
Published: November 2002

The purpose of this study was to investigate the effects of conceptual assignments and conceptual change discussions on students' achievement and misconceptions about force and motion. The study was conducted with 6 physics teachers and their 18 classes, consisting of 396 high school physics students. The teachers administered the Force Misconception and Force Achievement Tests to their physics classes as a pretest. The results obtained were used to match the 18 classes statistically. Students assigned to the conceptual assignment protocol completed five conceptual assignments about force and motion. Students assigned to the discussion method participated in conceptual change discussions. At the end of the 8‐week treatment period, the same tests were administered to all students as a posttest. The data were analyzed by using multivariate analysis of covariance, followed by protected univariate F test and step‐down analysis. The statistical results showed that the conceptual change discussion was an effective means of reducing the number of misconceptions students held about force and motion. The conceptual change discussion was also found significantly effective in improving students' achievement in force and motion. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 1001–1015, 2002
EDXRF studies on Chinese Yue ware
Authors: Wu J , Leung J. P.L , Li Z. , Stokes M. J.
Published: November 2002

The major and trace element composition of Chinese Yue ware, widely recognized
as the earliest Chinese porcelain (probably the earliest worldwide), is analysed
using non‐destructive, energy‐dispersive x‐ray fluorescence (EDXRF). The results
are subject to multivariate statistical analysis. Different compositional
patterns were found for specimens from different production sites (Cixi, Ningbo,
Shaoxin, Shangyu City, Zhejiang province). In particular the specimens excavated
at Hangzhou palace, called Mise (mysterious colour) ware, can be identified by
a small number of key element concentrations. Copyright © 2002 John
Wiley & Sons, Ltd.
Analysis of pigments from Spanish works of art using a portable EDXRF spectrometer
Authors: Ferrero J. L. , Roldán C. , Juanes D. , Rollano E. , Morera C.
Published: November 2002

Nowadays there is an intensive program for the conservation, restoration and analysis of the impressive and extensive Spanish cultural heritage. In the last few years, the Unidad de Arqueometria of the ICMUV has carry out a great quantity of in situ EDXRF analysis of pigments on materials of historic and cultural interest (altarpieces, frescoes, canvas, sculptures, etc.) from museums and churches of the whole of the Spanish geography. Here we present a few examples of the analysis of works of art using x‐ray fluorescence spectrometry with a portable system based on x‐ray tubes and a non‐cryogenic Si‐PIN detector. EDXRF qualitative and non‐destructive analyses of stone, pigments and preparation layer of a polychrome sculpture from the Iberian period are compared with results obtained with destructive analytical techniques. The identification of inorganic key elements in a mural painting from the 14th and 15th centuries allowed the characterization of the pigments and techniques used by the artists and were a great help in the restoration process. The EDXRF analysis of a partially burnt medieval altarpiece allowed us to establish the elemental composition of the pigments from damaged and non‐damaged areas. Finally, we present part of the systematic EDXRF analysis of the pigments on canvas from the work of Joaquín Sorolla with the objective of constructing a wide database on their pictorial materials. Copyright © 2002 John Wiley & Sons, Ltd.
Evacuation of hydatid liver cysts using laparoscopic trocar
Authors: Kayaalp Cuneyt
Published: November 2002

Several methods of reducing the likelihood of spilling live scolices during surgical removal of hydatid liver disease have been described. The aim was to determine the effectiveness and safety of laparoscopic trocar insertion for evacuation of hydatid liver cysts. This technique was used for 30 cysts in 19 patients who had surgery for hydatid liver disease. After establishing protection of the operative area, a laparoscopic trocar was inserted into the cyst at the most prominent point and the cyst was aspirated with large‐bore suction and filled with a scolicidal agent. The technique was not attempted in two small cysts (< 6 cm) located near the major blood vessels or in a single intraparenchymal cyst. Insertion of the trocar was successful in all remaining cysts, and there were no complications during the insertion or the evacuation. Successful evacuation (excellent and good outcomes) in unilocular, multilocular, and degenerated cysts were 100%, 84%, and 57%, respectively (p=0.144), with a total success rate of 82%. Although successful evacuation was achieved in both anterior (92%) and posterior‐superior located cysts (73%) (p=0.203), excellent outcomes were higher for the anterior cysts (73%) than for the posterior‐superior cysts (13%) (p=0.005). Successful evacuation outcomes for the large (τ 10 cm), middle‐sized (6 to 10 cm), and small cysts (< 6 cm) were 100%, 79%, and 67%, respectively (p=0.591). The patients have been followed for a mean of 11 months (range 3 to 24 months), and no recurrence has been recorded. Insertion and evacuation of the hydatid liver cysts with a laparoscopic trocar is a safe and effective procedure, and its limitations are minimal.
Results of pancreaticoduodenectomy for pancreatic cancer: Extended versus standard procedure
Authors: Iacono Calogero , Accordini Simone , Bortolasi Luca , Facci Enrico , Zamboni Giuseppe , Montresor Ettore , Marinello Peter Domenico , Serio Giovanni
Published: November 2002

In Western experience, the long‐term survival benefit after extended pancreaticoduodenectomy (EPD) in patients with pancreatic ductal adenocarcinoma is still controversial. The aim of this work was to evaluate weather EPD for pancreatic ductal adenocarcinoma prolongs long‐term survival compared to standard pancreaticoduodenectomy (SPD). From November 1992 to September 1996, we performed pancreatic resections in 30 patients affected by stage I–III pancreatic ductal adenocarcinoma: 13 patients underwent SPD and 17 patients underwent EPD, consecutively. The two groups of patients were similar for all the demographic, clinical, and pathological characteristics, and all the intraoperative factors considered except the number of resected lymph nodes (mean number per case=34.2 ± 15.5 in the EPD group versus 12.8 ± 3.6 in the SPD group, p<0.001) and the operative time (median time per case=375 minutes in the EPD group versus 270 minutes in the SPD group, p=0.009). Patients in the two groups experienced a similar postoperative course. The estimated survival probability at 1 and 3 years after operation was 0.76 (95% confidence interval [CI]: 0.49 to 0.90) and 0.24 (95% CI: 0.07 to 0.45) in the EPD group; 0.31 (95% CI: 0.09 to 0.55) and 0.08 (95% CI: 0.00 to 0.29) in the SPD group (p=0.014). According to a Cox model, the treatment was associated with R0 patients’ long‐term survival (SPD versus EPD: hazard ratio (HR)=4.82, 95% CI: 1.66 to 14.00, p=0.004). Grading of tumor differentiation was confirmed to be a relevant prognostic factor (poor versus moderate: HR=4.33, 95% CI: 1.49 to 12.61, p=0.007), whereas type of resection had no significant effect (pylorus‐preserving versus hemigastrectomy: HR=1.49, 95% CI: 0.56 to 3.95, p=0.42). The proportion of R0 patients with local recurrence was lower in the EPD group (20.0% versus 70.0%, p=0.034).
Does radical resection improve the survival in patients with carcinoma of the gallbladder who are 75 years old and older?
Authors: Onoyama Hirohiko , Ajiki Tetsuo , Takada Moriatsu , Urakawa Tomoaki , Saitoh Yoichi
Published: November 2002

Radical resections have been reported to improve the surgical outcome for patients with carcinoma of the gallbladder, in recent years surgeons have had more opportunities to operate on elderly patients. We investigated whether the survival rate of aged patients who had radical resections were better than rates for those who had simple cholecystectomy. Of the 300 patients treated for carcinoma of the gallbladder between 1971 and 1999, 206 resected cases (except pancreaticoduodenectomy and hepatectomy) were divided into two groups: age 75 years or older, 54 patients (the older group), and age less than 75 years, 152 patients (the younger group). Clinical features and progression of the carcinomas did not differ between the two groups. In the older group, 22 patients (40.7%) had simple cholecystectomy, 32 (59.3%) had radical resections; in the younger group, 65 patients (42.8%) had simple cholecystectomy, and 87 (57.3%) had radical resection. None of the older patients who had radical resection died postoperatively. Postoperative survival was not different between the two groups. In the older group the 5‐year survival rate for patients who had radical resections was better (60.9%) than the rate for those who had simple cholecystectomy (14.1%) (p=0.0098). Radical resection is effective for the aged patients with the carcinoma of gallbladder.
Surgery of chronic pancreatitis: Chronicle of confusion and despair
Authors: Modlin Irvin M. , Kidd Mark , Hults Christopher , Hinoue Toshi
Published: November 2002

The evolution of surgery for pancreatitic disease has been arduous owing to the technical difficulties of addressing the organ and the lack of understanding the mechanisms of the disease processes involving it. In particular, the tardy advance of surgery in the management of chronic pancreatitis exemplifies these problems. Because no specific target has been identified, mechanical intervention has for the most part reflected intuitive or creative attempts to address perceived pathologic issues such as sphincter disease, calculi, and fibrotic masses. The past and present remain a confusion of etiologies and diagnoses. Treatment remains for the most part a dramatically disappointing scenario, and both patients and their physicians are frustrated. Although the remarkable technologic progress exhibited by the odyssey of operative strategy from simple drainage, to ductal drainage, to the complex refinements of extensive resection is a testimonial to surgical skill and determination, it has been nullified to a large extent by the inability to address the initiating factors of the disease or alter those that engender progress of the pathology. It is not unreasonable to recognize that we are facing an enigmatic disease process generically classified as “chronic pancreatitis” for want of any more specific terminology. In the light of our current knowledge and experience, intervention should probably be modest in the extreme and limited to centers and individuals with expertise or who are involved in specific studies to determine the precise criteria and techniques necessary for optimum intervention. It is important that when charting such a course future surgeons involved in the management of chronic pancreatitis have an understanding of the historical evolution of the subject. As Theodor Billroth, the greatest of the surgical innovators remarked: “An awareness of the past is necessary to comprehend the present, and without it no consideration of the future is possible.”
Modal analysis and gain calculations for a sheet electron beam in a ridged waveguide slow-wave structure
Authors: Carlsten Bruce E.
Published: November 2002

A mode analysis is presented for the case of a planar electron beam in a ridged waveguide slow-wave structure. By matching boundary conditions between a Fourier expansion of the mode between the ridges with a space-harmonic expansion of the mode in the region below the ridges, a dispersion relation for a traveling-wave interaction is found. The dispersion relation is numerically solved for both the case with and without beam. For the nominal geometry, gains as high as 30 dB/cm at 300 GHz are found for a 15 A, 155 keV beam.