bluuebunny/crossref_metadata_2025 huggingface dataset:
Image cytometric bcl‐2:bax and bcl‐2:bcl‐x ratios in invasive breast carcinoma: Correlation with prognosis
Authors: Schiller A.B. , Clark W.S. , Cotsonis G. , Lawson D. , DeRose P.B. , Cohen C.
Published: August 2002

Background: The bcl‐2 family of proteins are important regulators of apoptosis. Some of the members, such as bcl‐2 and bcl‐xL, inhibit cell death, whereas others, such as bax and bcl‐xS, promote cell death. We evaluated the ratios of bcl‐2:bax and bcl‐2:bcl‐x expression by image cytometry in invasive breast carcinoma to determine prognostic significance. Design: Five‐micron sections of formalin‐fixed, paraffin‐embedded tissue from 88 invasive breast carcinomas were immunostained using steam antigen retrieval, an avidin biotin‐complex technique with automated stainer and primary antibodies against bcl‐2 (1/160; Dako, Carpenteria, CA), bax (1/1,500; PharMingen, San Diego, CA), and bcl‐x (1/1,500; PharMingen). Positive controls were tonsil (bcl‐2) and normal breast (bax and bcl‐x) tissue samples. Immunostain was measured in 15 high power fields as percentage positive area (PPA) in nuclei and cytoplasm using the CAS 200 image analyzer (Becton Dickinson, San Jose, CA). Results: Median follow‐up was 105 months (range 11–130). Significantly improved disease‐free survival was found in patients with a bcl‐2:bcl‐x ratio ≥ 1 by univariate and multivariate analyses. The bcl‐2:bax ratio was not predictive of overall or disease‐free survival. A significant difference in overall and disease‐free survival was found between carcinomas with positive and negative bcl‐2 expression by univariate analysis; by multivariate analysis, bcl‐2 expression was an independent prognostic factor for disease‐free survival. The 5‐year survival rates were 77% and 50% in patients with bcl‐2–positive and bcl‐2–negative carcinomas, respectively. Conclusion: A bcl‐2:bcl‐x ratio ≥ 1, assessed by image cytometry, is significantly associated with improved disease‐free survival in patients with invasive breast carcinoma. Significantly increased overall and disease‐free survival is associated with positive bcl‐2 expression. Cytometry (Clin. Cytometry) 50:203–209, 2002. © 2002 Wiley‐Liss, Inc.
Determination of ploidy and steroid receptor status in breast cancer by laser scanning cytometry
Authors: Bollmann Reinhard , Torka Robert , Schmitz Jörg , Bollmann Magdolna , Méhes Gábor
Published: August 2002

Background: Measurements on DNA content and steroid receptor status in breast cancer are of great clinical interest. Objective determination of estrogen and progesterone receptor expression should help to define the lowest levels of positivity still responding to adjuvant antihormonal therapy. For this purpose, a simple protocol for laser scanning cytometry is presented. Methods: Analysis of 54 routine breast cancer samples was performed by laser scanning cytometry (LSC). To obtain single cell preparations from fresh tumor tissue, slides were prepared using the Cervisoft cytological device. Exact determination of tumor cell DNA content was done by referring to the CD45‐positive tissue leukocyte fraction as the internal diploid reference cell population. Steroid receptor‐expressing cells were detected by indirect immunolabeling. Results: Indirect immunofluorescence allowed the best quantification of both the estrogen and progesterone receptor‐expressing cell fractions by LSC. The number of receptor‐expressing cells could be given in percentage. For comparison, the 10% cutoff value was used to determine receptor positivity. Conclusion: LSC enabled a simple, reliable, and inexpensive determination of DNA index and steroid receptor expression in breast cancer specimens by objective criteria. Cytometry (Clin. Cytometry) 50:210–215, 2002. © 2002 Wiley‐Liss, Inc.
Combined DNA flow cytometry and sorting with k‐ras2 mutation spectrum analysis and the prognosis of human sporadic colorectal cancer
Authors: Geido Elio , Sciutto Andrea , Rubagotti Alessandra , Oliani Cristina , Monaco Roberto , Risio Mauro , Giaretti Walter
Published: August 2002

Background: Activation of the k‐ras2 pathways and chromosomal instability leading to aneuploidy in human sporadic colorectal cancer (sCRC) is essential to the tumor cell ability to survive, grow, and metastatize. Methods: The study included 135 patients with sCRC who were followed up for a median of 72 months. Multiple fresh‐frozen fragments obtained from superficial and invasive areas of the tumors were mixed and used to detect the degree of DNA aneuploidy (DNA index [DI]) and S‐phase fraction by two scatter signals and 4,6‐diamidino‐2‐phenylindole‐2‐hydrocloride (DAPI) fluorescence flow cytometry (FCM). PCR amplification and k‐ras2 mutation spectrum analysis were performed using enriched epithelial nuclei after sorting DNA aneuploid nuclei and DNA diploid nuclei from which tissue‐infiltrating lymphocytes were absent. Results: DNA aneuploidy was detected in 98 (73%) and k‐ras2 mutations in 54 cases (40%). Univariate analyses of overall survival with both Dukes' A to D or B to C series of cases showed that DNA multiple aneuploidy, k‐ras2 mutations, older age, and distal site, but not increased S‐phase fraction, were predictive of worse outcome. Multivariate Cox models strongly indicated that k‐ras2 mutations, but neither single nor multiple DNA aneuploidy, were an independent prognostic factor in both series of patients. In particular, with B and C Dukes' stage patients (n = 110), the relative risk (RR) of death was above 2.5 with k‐ras2 mutations and above 3 with the G→C/T transversions. Conclusion: Combined FCM and k‐ras2 analysis may be used to predict long‐term increased risk of death in sCRC patients. Cytometry (Clin. Cytometry) 50:216–224, 2002. © 2002 Wiley‐Liss, Inc.
Immunophenotypic characterization of myelopoiesis in early and late myelodysplastic syndromes: Use of CD44 as an aid in early diagnosis
Authors: Karmon Yuval , Manaster J. , Chezar J.
Published: August 2002

We investigated the possibility that myeloid cells from the bone marrow (BM) of myelodysplastic patients differ in their expression of CD44 antigen compared with expression of the antigen in normal controls. In addition, two triple‐surface marker assays incorporating, respectively, CD44/CD33/CD66 and CD33/CD34/HLA‐DR were used to evaluate the degree of myeloid maturation and assess the number of blasts in BM by flow cytometry. Patients with early‐stage myelodysplastic syndrome (MDS; RA [FAB classification]) have significantly decreased expression of CD44 on gated myeloid cells. In contrast, patients with late‐stage MDS (RAEB and RAEB‐T [FAB classification]) showed an elevated expression of CD44 and an increased number of CD34 blasts compared with early‐stage MDS patients and normal controls. Late‐stage MDS patients also had an increase in the immature myeloid compartment (CD66 weak expression) compared with early‐stage MDS patients and normal controls. We have already included this assay as part of our MDS evaluation protocol alongside BM morphology and cytogenetics. Cytometry (Clin. Cytometry) 50:225–230, 2002. © 2002 Wiley‐Liss, Inc.
Improved flow cytometric method to enumerate residual cells: Minimal linear detection limits for platelets, erythrocytes, and leukocytes
Authors: Pichler J. , Printz D. , Scharner D. , Trbojevic D. , Siekmann J. , Fritsch G.
Published: August 2002

Increasing demand for quality control of blood products requires more sensitive methods to enumerate residual cells. Presently, the reported threshold (in cells per microliter) is 400 for red blood cells, 30–500 for platelets, and 1 for leukocytes. To examine precision and linearity in enumerating residual platelets and red blood cells, EDTA‐anticoagulated blood from healthy donors was serially diluted with serum, stained in TruCount tubes using a no‐lyse/no‐wash procedure and a monoclonal antibody cocktail against the CD42a (FL1) and glycophorin‐A (FL2) epitopes, and analyzed by flow cytometry. Leukocyte counts were determined in separate tubes. Cell preparation and analysis were performed once for 20 blood samples each and 20 times using the same specimen. Acquisition from the same tube was performed separately for platelets (threshold on FL1) and red blood cells (threshold on FL2). Multiparameter analysis was used for data evaluation. Linear results were obtained for platelets per microliter between 3,410 and 5 and for red blood cells per microliter between 54,000 and 3. For the lower cell concentrations, the coefficient of variation was 16.7% for platelets and 10.9% for red blood cells. The presented method allows the distinction between physiologically intact and ghost red blood cells. The method represents a reliable, sensitive, and accurate approach to quantify platelets and red blood cells in diluted blood. It can be applied to enumerate residual cells in plasma products and meets the increasing demand for quality control in blood components. Cytometry (Clin. Cytometry) 50:231–237, 2002. © 2002 Wiley‐Liss, Inc.
Effects of protein kinase Cβ inhibition on neurovascular dysfunction in diabetic rats: interaction with oxidative stress and essential fatty acid dysmetabolism
Authors: Cameron Norman E. , Cotter Mary A.
Published: August 2002

Background

Elevated protein kinase C (PKC) activity is thought to play a substantial role in the aetiology of diabetic microvascular complications, the PKCβ isoform being identified as particularly important. Neuropathy has a vascular component; therefore, one aim was to assess whether the PKCβ inhibitor, LY333531, could correct nerve conduction velocity (NCV) and perfusion deficits in diabetic rats. Neurovascular dysfunction also depends on oxidant stress and impaired ω‐6 essential fatty acid metabolism; correctable by antioxidant and γ‐linolenic acid (GLA) treatments, respectively. A second aim was to assess whether there were interactions between these mechanisms and PKCβ‐mediated effects.

Methods

Diabetes was induced by streptozotocin; duration was 8 weeks. NCV was monitored and blood flow was assessed by hydrogen clearance microelectrode polarography.

Results

Diabetes caused 19.7% and 13.9% reductions in sciatic motor and saphenous sensory NCV, respectively. Two weeks of LY333531 treatment dose‐dependently corrected these deficits. A dose of 10 mg kg−1day−1gave non‐diabetic NCV values and also completely corrected a 50% diabetic reduction in sciatic endoneurial blood flow. Low‐dose (0.25 mg kg−1day−1) LY333531 had modest effects (∼20% correction) on NCV and sciatic perfusion. However, when combined with equi‐effective doses of the antioxidants vitamin E or α‐lipoic acid, or GLA, motor and sensory NCV and sciatic nerve perfusion were in the non‐diabetic range. The joint effect was equivalent to that of the 10 mg kg−1day−1LY333531 dose, demonstrating synergism between PKCβ, oxidative stress and essential fatty acid mechanisms.

Conclusions

LY333531, alone or combined with antioxidants or GLA, could form the basis for therapeutic intervention in neuropathy, which requires assessment in clinical trials. Copyright © 2002 John Wiley & Sons, Ltd.
The Continuous Glucose Monitoring System (CGMS) in type 1 diabetic children is the way to reduce hypoglycemic risk
Authors: Schiaffini R. , Ciampalini P. , Fierabracci A. , Spera S. , Borrelli P. , Bottazzo G. F. , Crinò A.
Published: August 2002

Background

Diabetic children treated with intensive insulin therapy are showing a dangerous increase in severe hypoglycemic episodes. The Continuous Glucose Monitoring System (CGMS) allows glycemic profiles to be monitored over a 72‐h period. The aim of the present study was to evaluate whether this system is sufficiently sensitive to detect asymptomatic hypoglycemia, and to determine if its periodic application would help to minimize the hypoglycemic risk in children with type 1 diabetes mellitus (T1DM).

Methods

Twenty‐seven T1DM children (age range 6–13.1 years) were enrolled in the study. The sensor was inserted subcutaneously in each patient and the standard four or five registrations of capillary glycemia per day were performed. Eighteen patients continued in the study and the glucose sensor was again inserted after a 6‐week interval. At the beginning and end of the study, fructosamine, glycosylated hemoglobin (HbA1c), median glycemia, number and duration of hypoglycemic events and insulin requirement were evaluated.

Results

A significantly higher number of asymptomatic hypoglycemic events was revealed by CGMS in comparison with the standard system (3.6 ± 2.3 vs 0.7 ± 0.9; p < 0.0001). In patients who continued in the study, insulin therapy adjustments reduced the incidence of hypoglycemic events (2.5 ± 1.7 vs 3.9 ± 2.2; p < 0.05). At the 6‐week point, the fructosamine level was reduced (330 ± 30 vs 349 ± 24 µmol/l; p < 0.05).

Conclusions

The CGMS is a useful device not only for detecting unrecognized hypoglycemia, but also for modifying insulin therapy in order to reduce hypoglycemic events. The system appears to be useful in avoiding long exposure to hypoglycemia. Copyright © 2002 John Wiley & Sons, Ltd.
Continuous glucose monitoring in managing diabetes in children
Authors: Speiser Phyllis W.
Published: August 2002

Continuous glucose monitoring (CGM) devices have now been added to the repertoire of technological devices useful in the management of patients with diabetes. In this issue, Schiaffini and colleagues confirm and extend published data describing the benefits of CGM in diabetic children. Specifically, such monitoring enables clinicians to detect occult hypoglycemia not otherwise discernable with intermittent testing of blood glucose. Although results of monitoring are not yet available in real time, the data can be used to adjust insulin regimens to allow more effective glycemic control. This is especially important in the pediatric population for whom strict glycemic control has traditionally been limited owing to concerns about the negative effects of hypoglycemia on the developing central nervous system. Additionally, postprandial hyperglycemia can be more readily detected and controlled. CGM provides new and important informaton not necessarily provided by measurement of HbA1c, and will likely prove an indispensable adjunct to diabetes care. Finally, this procedure has potential applications in the diagnosis and management of patients with other metabolic disorders. Copyright © 2002 John Wiley & Sons, Ltd.
Considerations on blood glucose management in Type 2 diabetes mellitus
Authors: Home Philip , Chacra Antonio , Chan Juliana , Emslie‐Smith Alistair , Sorensen Lea , Crombrugge Paul Van
Published: August 2002

In recent years the benefits of more intensive management in preventing or delaying the development and progression of diabetic complications have been well documented. What is not as well documented is how to motivate the person with diabetes to manage the condition, how to set, assess and quantify glucose goals, and the glucose variables that should be routinely measured. This review discusses the importance of setting targets and communicating them in a way that the patient understands. When aiming for a glycaemia target, balance is required (1) between achieving reduction of complications and causing an increased degree of hypoglycaemia, and (2) between what is achievable and what degree of benefit is gained. Target values given in guidelines should be adapted by the clinician to take into account the patient's susceptibility to hypoglycaemia, stage and type of complications, age and life expectancy, co‐morbidity, social environment, understanding of the steps required and level of commitment to the treatment. Several suggestions are given regarding possible improvements and amendments to existing guidelines for diabetes management in treating to glucose goal. For example, attention should be drawn to the need to individualise goals and to consider education, long‐term support, patient needs and treatment outcome when formulating diabetes management plans. The relative properties of the different glucose variables—fasting plasma glucose (FPG), postprandial plasma glucose (PPG), glycated haemoglobin A1c (HbA1c), and glycated protein—in terms of their convenience of measurement, usefulness and relevance to the physician and patient are also evaluated. When prioritising the variables to be measured it is suggested that where feasible, HbA1c should be the standard measurement by which to gauge risk and treatment efficacy. Serial measurements should be made and, where possible, the use of blood glucose meters encouraged, in order to obtain a blood glucose profile for the patient. Copyright © 2002 John Wiley & Sons, Ltd.
Haemodynamics in microvascular complications in type 1 diabetes
Authors: Candido Riccardo , Allen Terri J.
Published: August 2002

Type 1 diabetes is commonly associated with microvascular complications. Most of the microvascular blood vessels are involved but those in the kidney, retina and large nerves exhibit the more significant pathology. Haemodynamic and metabolic factors both alone and through the activation of a common pathway contribute to the characteristic dysfunction observed in diabetic vasculopathy. The haemodynamic abnormalities in type 1 diabetes are characterized by increased systemic blood pressure and altered blood flow with subsequent activation of various vasoactive factors, which can contribute to the maintenance of the haemodynamic alterations and to the development and progression of the microvascular complications. These vasoactive factors include vasoconstrictors such as angiotensin II, and endothelin, as well as vasodilators such as nitric oxide (NO). Systemic hypertension and vasoactive factors independently and in interaction with the metabolic pathway activate intracellular second messengers, nuclear transcription factors and various growth factors which lead to the typical functional and structural alterations of diabetic microvascular complications. Therapeutic strategies involved in the management and prevention of diabetic complications currently include antihypertensive agents, particularly those that interrupt the renin–angiotensin system. Further understanding of the interactions among the vasoactive factors, the intracellular second messengers and the growth factors may help to identify novel strategies to influence the action of the vasoactive factors. These novel therapies, together with specific inhibitors of the metabolic pathway or the common pathway, may provide the possibility of preventing or even reversing the progression of diabetic microvascular complications. Copyright © 2002 John Wiley & Sons, Ltd.
Alpha2‐HS glycoprotein: a protein in search of a function
Authors: Arnaud Philippe , Kalabay Laszlo
Published: August 2002

In this issue (pp. 305–310) Jun Ren and Amy J. Davidoff author an article entitled ‘Alpha2‐HS glycoprotein, a putative inhibitor of tyrosine kinase, prevents glucose toxicity associated with cardiomyocyte dysfunction’. The protein responsible for this biological activity has recently come to the forefront of research on the biological activity of plasma proteins. Copyright © 2002 John Wiley & Sons, Ltd.
The DPT‐1 trial: a negative result with lessons for future type 1 diabetes prevention
Authors: Pozzilli Paolo
Published: August 2002

The author comments on the DPT‐1 Trial and why the observed negative outcome in preventing diabetes in first‐degree relatives of type 1 diabetic patients by parenteral insulin administration may have occurred and what can be gathered from this large study. There were three main lessons to be learned from the DPT‐1 Trial as follows. (1) Large preventive trials of type 1 diabetes are feasible in first‐degree relatives of type 1 diabetic patients and other preventive approaches may be now envisaged. (2) The natural history of type 1 diabetes, at least in its final years before clinical onset, has been elucidated and reiterates the relevance of our present predictive tools (autoantibodies) for identifying individuals at risk for the disease. (3) Strict follow‐up of enrolled subjects in trials permits an earlier diagnosis of the disease with less frequency of ketoacidosis and implementation of insulin therapy when higher C‐peptide levels are present. DPT‐1 has paved the way on how to proceed and new trials will be planned benefiting from such experience. Copyright © 2002 John Wiley & Sons, Ltd.
The anxiety buffering function of close relationships: mortality salience effects on the readiness to compromise mate selection standards
Authors: Hirschberger Gilad , Florian Victor , Mikulincer Mario
Published: August 2002

This research examines the utility of a terror management approach to understanding the motivations and emotional consequences of compromise in mate selection. One hundred and sixty‐eight undergraduates completed a self‐esteem scale and a scale tapping ideal mate characteristics, and were then assigned either to a mortality salience, physical pain salience, or neutral condition. Half of the participants rated their readiness to compromise ideal mate standards and the remaining half completed a neutral scale. Then, participants completed a scale tapping their emotional state. Mortality salience led participants to significantly compromise their mate requirements. This effect seemed to be most pronounced among high self‐esteem participants who also experienced the greatest amount of guilt when compromising under mortality salient conditions. Low self‐esteem participants who compromised under mortality salient conditions reacted with higher levels of shame. The results are discussed in terms of the anxiety buffering functions of close relationships. Copyright © 2002 John Wiley & Sons, Ltd.
Blushing after a moral transgression in a prisoner's dilemma game: appeasing or revealing?
Authors: de Jong Peter J. , Peters Madelon , De Cremer David , Vranken Christien
Published: August 2002

This study investigated the alleged remedial effects of blushing in the context of real‐time interactions. Therefore, 30 pairs of prosocial individuals participated in a prisoner's dilemma ‘game’. The experiment was framed as an objective test of moral behaviour. To elicit a shameful moral transgression, one individual of each pair was instructed to select the non‐habitual cheat‐option on a pre‐defined target trial. Supporting the idea that violation of shared rules elicits blushing, the defectors displayed a blush on the target trial. Yet, unexpectedly, there was a negative relationship between the observed blush intensity and the trustworthiness attributed to the defectors. One explanation might be that the ‘victims’ used the blush response to deduce and interpret the defector's motive. As the antecedent behaviour involved in the present context was not completely unambiguous with respect to the perpetrators' motive (e.g. innocent playing around vs. maximizing outcomes) the observers might have interpreted blushing as signaling that the situation should be interpreted as an intentional violation of a social standard. Together the available evidence suggests that only in the context of unambiguous antecedent behaviours blushing has remedial effects, whereas in ambiguous situations blushing has undesirable revealing effects. Copyright © 2002 John Wiley & Sons, Ltd.
Levels of consensus and majority and minority influence
Authors: Martin Robin , Gardikiotis Antonis , Hewstone Miles
Published: August 2002

Three experiments are reported which examine the effects of consensus information on majority and minority influence. In all experiments two levels of consensus difference were examined; large (82% versus 18%) and small (52% versus 48%). Experiment 1 showed that a majority source had more influence than a minority source, irrespective of consensus level. Experiment 2 examined the cause of this effect by presenting only the source label (‘majority’ versus ‘minority’), only the consensus information (percentages) or both. The superior influence of the majority was again found when either (a) both source label and consensus information were given (replicating Experiment 1) and (b) only consensus information was given, but not when (c) only the source label was given. The results showed majority influence was due to the consensus information indicating more than 50% of the population supported that position. Experiment 3 also manipulated message quality (strong versus weak arguments) to identify whether systematic processing had occurred. Message quality only had an impact with the minority of 18%. These studies show that consensus information has different effects for majority and minority influence. For majority influence, having over 50% support is sufficient to cause compliance while for a minority there are advantages to being numerically small, in terms of leading to detailed processing of its message. Copyright © 2002 John Wiley & Sons, Ltd.
Causal attribution from covariation information: the evidential evaluation model
Authors: White Peter A.
Published: August 2002

It is hypothesized that causal attributions are made by transforming covariation information into evidence according to notions of evidential value, and that causal judgement is a function of the proportion of instances that are evaluated as confirmatory for the causal hypothesis under test: this is called the evidential evaluation model. An experiment was designed to test the judgemental rule in this model by setting up problems presenting consensus, distinctiveness, and consistency information in which the proportion of confirmatory instances varied but the objective contingency did not. It was found that judgements tended to vary with the proportion of confirmatory instances. Several other current models of causal judgement or causal attribution fail to account for this result. Similar findings have been obtained in studies of causal judgement from contingency information, so the present findings support an argument that the evidential evaluation model provides a unified account of judgement in both domains. Copyright © 2002 John Wiley & Sons, Ltd.
Study of a semi‐active stiffness damper under various earthquake inputs
Authors: Djajakesukma S. L. , Samali B. , Nguyen H.
Published: August 2002

Semi‐active stiffness damper (SASD) is one of many semi‐active control systems with the capability to mitigate the dynamic response using only a small amount of external power. The system consists of a hydraulic damper connected to the bracing frame in a selected story unit. In this paper, study of a SASD in two building models of five‐stories under four benchmark earthquake records is reported. The purpose of this study is to evaluate the effectiveness of the control system against structure type and varying earthquake inputs. Various control laws are chosen to work with SASD, such as: resetting control, switching control, linear quadratic regulator (LQR) and modified LQR, and the results are compared with no control and passive control cases. Numerical results show that the use of a SASD is effective in reducing seismic responses. Control effectiveness is dependent on the type of structure and earthquake excitation. Passive control is less effective than other control cases as expected. Resetting control, switching control and LQR generally perform similarly in response reduction. While modified LQR is more efficient and robust compared with other control algorithms. Copyright © 2002 John Wiley & Sons, Ltd.
Study on effects of damping in laminated rubber bearings on seismic responses for a ⅛ scale isolated test structure
Authors: Yoo Bong , Kim Yang‐Hann
Published: August 2002

The effects of damping in various laminated rubber bearings (LRB) on the seismic response of a ⅛‐scale isolated test structure are investigated by shaking table tests and seismic response analyses. A series of shaking table tests of the structure were performed for a fixed base design and for a base isolation design. Two different types of LRB were used: natural rubber bearings (NRB) and lead rubber bearings (LLRB). Three different designs for the LLRB were tested; each design had a different diameter of lead plug, and thus, different damping values. Artificial time histories of peak ground acceleration 0.4g were used in both the tests and the analyses. In both shaking table tests and analyses, as expected, the acceleration responses of the seismically isolated test structure were considerably reduced. However, the shear displacement at the isolators was increased. To reduce the shear displacement in the isolators, the diameter of the lead plug in the LLRB had to be enlarged to increase isolator damping by more than 24%. This caused the isolator stiffness to increase, and resulted in amplifying the floor acceleration response spectra of the isolated test structure in the higher frequency ranges with a monotonic reduction of isolator shear displacement. Copyright © 2002 John Wiley & Sons, Ltd.
Analysis and performance of a predictor‐multicorrector Time Discontinuous Galerkin method in non‐linear elastodynamics
Authors: Bursi Oreste S. , Mancuso Massimo
Published: August 2002

A predictor‐multicorrector implementation of a Time Discontinuous Galerkin method for non‐linear dynamic analysis is described. This implementation is intended to limit the high computational expense typically required by implicit Time Discontinuous Galerkin methods, without degrading their accuracy and stability properties. The algorithm is analysed with reference to conservative Duffing oscillators for which closed‐form solutions are available. Therefore, insight into the accuracy and stability properties of the predictor‐multicorrector algorithm for different approximations of non‐linear internal forces is gained, showing that the properties of the underlying scheme can be substantially retained. Finally, the results of representative numerical simulations relevant to Duffing oscillators and to a stiff spring pendulum discretized with finite elements illustrate the performance of the numerical scheme and confirm the analytical estimates. Copyright © 2002 John Wiley & Sons, Ltd.
Characteristics of earthquake ground motions and the H/V of microtremors in the southwestern part of Taiwan
Authors: Huang Huey‐Chu
Published: August 2002

The relationships between the spectral characteristics of earthquake ground motions and those of micro‐tremors are investigated using the observed data from a dense strong‐motion network consisting of 108 stations in the Yun‐Li, Chia‐Yi and Tai‐Nan areas in southwestern Taiwan. Many high‐quality recordings, including those of the 921 Chi‐Chi earthquake (Mw=7.6), the 1022 Chia‐Yi mainshock (ML=6.4), the 1022 major aftershock (ML=6.0), as well as some weak motion events are selected to evaluate site responses. Microtremor measurements are also performed at most ground motion stations. With many stations in the area located on an alluvium structure, however, it is difficult to find good reference stations on rock sites, which therefore necessitates the calculation of single‐station H/V ratios. The predominant frequencies obtained from H/V ratios are consistent with those from spectral ratios. The site characteristics between the strong and weak events are different, however. This implies that a nonlinear effect probably occurred with the strong‐motion events. The main peak in the H/V spectra of the microtremors is in good agreement with the first peak obtained from the spectra of earthquake ground motions. It is reasonable to claim that the main peak reflects the deep underground structure. On the basis of the H/V ratios of the microtremors, it is concluded that the lower predominant frequencies appear in the plain area, while the higher values are near the mountainous region. Copyright © 2002 John Wiley & Sons, Ltd.
Amplification of earthquake ground motion by steep topographic irregularities
Authors: Paolucci Roberto
Published: August 2002

The problem of amplification of seismic waves by surface topographic irregularities is addressed through analytical and numerical investigations. First, a closed‐form expression for estimating the fundamental vibration frequency of homogeneous triangular mountains is obtained, using Rayleigh's method. Subsequently, numerical modelling based on the spectral element approximation is used to study the 3D seismic response of several real steep topographic irregularities excited by vertically propagating plane S‐waves. A topographic amplification factor is obtained for each case, by a suitable average of the ratio of acceleration response spectra of output vs input motion. The 3D amplification factors are then compared with those derived by 2D analyses as well as with the topographic factors recommended in Eurocode 8 for seismic design. Copyright © 2002 John Wiley & Sons, Ltd.
Market‐based control of linear structural systems
Authors: Lynch Jerome Peter , Law Kincho H.
Published: August 2002

To limit the response of structures during external disturbances such as strong winds or large seismic events, structural control systems can be used. In the structural engineering field, attention has been shifted from active control to semi‐active control systems. Unlike active control system devices, semi‐active devices are compact, have efficient power consumption characteristics and are less expensive. As a result, an environment of a large number of actuators and sensors will result, rendering a complex large‐scale dynamic system. Such a system is best controlled by a decentralized approach such as market‐based control (MBC). In MBC, the system is modelled as a market place of buyers and sellers that leads to an efficient allocation of control power. The resulting MBC solution is shown to be locally Pareto optimal. This novel control approach is applied to three linear structural systems ranging from a one‐storey structure to a 20‐storey structure, all controlled by semi‐active hydraulic dampers. It is shown that MBC is competitive in the reduction of structural responses during large seismic loadings as compared to the centralized control approach of the linear quadratic regulation controller. Copyright © 2002 John Wiley & Sons, Ltd.
Dieting and desire for weight loss among adolescents in Denmark: a questionnaire survey
Authors: Waaddegaard Mette , Petersen Tove
Published: August 2002

Objective:

To report on the first study in Denmark of the prevalence of dieting and other weight‐loss behaviours among adolescents.

Method:

A cross‐sectional study of 2094 pupils from grade 8–12, aged 14–21 years, throughout Denmark. The pupils responded to a self‐administered 49‐item questionnaire, which was constructed by an Expert Committee in the Danish National Board of Health.

Results:

The prevalence of dieting and other weight‐loss behaviours were comparable to results from other countries, particularly from the Nordic countries. Dieting was dependent on BMI and sex and did not increase with age. However, the desire for weight loss increased with age for both sexes and body dissatisfaction became more extreme with age. Many boys desired a weight gain instead of a weight loss.

Discussion:

Dieting and other weight control behaviours increased with increasing BMI. However, most dieting and wish for weight loss was not justified by obesity but seemed to depend on a perception of being overweight. The need for identifying adolescents with at‐risk behaviour related to eating disorders is emphasized. Copyright © 2001 John Wiley & Sons, Ltd and Eating Disorders Association.
The development of a decisional balance scale for anorexia nervosa
Authors: Cockell Sarah J. , Geller Josie , Linden Wolfgang
Published: August 2002

The purpose of this study was to develop a Decisional Balance (DB) measure of readiness for change in anorexia nervosa. A total of 246 women with anorexia nervosa completed a 60‐item DB scale. A 3‐factor solution provided the best fit for the DB data, which reduced the scale to 30 items. Two of these, namely Burdens and Benefits, resembled the pro and con factors found in previous research. The third factor, Functional Avoidance, was unique to the decisional balance literature; it included items reflecting the ways that anorexia nervosa provides a way to avoid dealing with aversive emotions, challenges, and responsibilities. The DB demonstrated good internal consistency and acceptable test–retest reliability. This measure could be used to help us better understand the shifts that occur as individuals with anorexia nervosa develop a desire to change. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Structured therapeutic writing tasks as an adjunct to treatment in eating disorders
Authors: Schmidt Ulrike , Bone Gillian , Hems Saskia , Lessem Joey , Treasure Janet
Published: August 2002

Eating disorder patients, especially those with anorexia nervosa, are experientially avoidant. This group of patients finds talking treatments difficult and many standard psychotherapeutic techniques are difficult to implement. This paper discusses why therapeutic writing might be a useful adjunct to the treatment of eating disorders. Different types of therapeutic writing exercises may be useful at different stages of treatment and might aid the therapeutic process in different ways. The limitations of therapeutic writing are also discussed. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Does ecological momentary assessment improve cognitive behavioural therapy for binge eating disorder? A pilot study
Authors: le Grange Daniel , Gorin Amy , Dymek Maureen , Stone Arthur
Published: August 2002

The purpose of this pilot study was to test whether self‐monitoring in CBT could be enhanced in order to improve the identification of proximal antecedents of binge eating in binge eating disorder (BED). CBT was modified by asking participants to monitor all eating intensively through ecological momentary assessment (EMA). A total of 41 females (mean BMI = 37.9; SD = 8.2) meeting DSM‐IV criteria for BED were randomly assigned to one of two group treatments; CBT (n = 22) or CBT with EMA (n = 19). CBT with EMA differed from CBT in that for the first 2 weeks of treatment, participants completed detailed pocket diaries about mood, events, etc., when signalled at random by programmable wristwatches, as well as at all times when eating. All participants completed measures of eating (EDE‐Q, TFEQ, EES) and general psychopathology (BDI, RSE) before treatment, at the end of treatment, and at 1‐year follow‐up. While both treatment groups showed improvement on the outcome variables of interest, the individual data gained via EMA did not significantly enhance standard CBT. Therefore, it is unlikely that further research incorporating EMA as a therapeutic technique within CBT for BED will be compelling. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Sex differences in body satisfaction, feeling fat and pressure to diet among Chinese adolescents in Hong Kong
Authors: Lam T. H. , Stewart Sunita Mahtani , Leung Gabriel , Ho S. Y. , Fan Alex Hoi , Ma Alison L. T.
Published: August 2002

Objective:

This study examines body size, body satisfaction (BodSat), feelings of fatness (FeelFat) and pressure to diet (PressDiet) in 356 non‐referred Hong Kong Chinese adolescents. The primary interest was to elucidate the mechanisms that increase risk for girls to translate their dissatisfaction with their bodies into weight restriction efforts.

Method:

Secondary school boys (n = 192) and girls (n = 164) completed selected scales of the Body Attitudes Questionnaire with measures for BodSat, FeelFat and PressDiet. Body mass index (BMI) was calculated based on current weight and height.

Results:

As predicted, the association between FeelFat and PressDiet was stronger in girls than boys. FeelFat mediated the effect of BodSat and BMI on PressDiet in girls. In contrast, in boys, BMI influenced PressDiet independently of FeelFat.

Discussion:

These findings suggest that the effect of BMI on PressDiet may be a protective factor against eating pathology in boys. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Spatial patterns of water surface topography at a river confluence
Authors: Biron Pascale M. , Richer Antoine , Kirkbride Alistair D. , Roy André G. , Han Sangsoo
Published: August 2002

Understanding flow structures in river confluences has largely been the product of interpretations made from measured flow velocity data. Here, we turn the attention to the investigation of the patterns of both the average and standard deviations of the micro‐topography of the water surface at an asymmetrical natural discordant confluence for different flow conditions. Water surface topography is measured using a total station to survey the position of a reflector mounted on a custom‐built raft. To limit error problems related to changes in the water level, measurements are taken and analysed by cross‐stream transects where five water surface profiles are taken before moving to the next transect. Three‐dimensional numerical simulations of the flow dynamics at the field site are used to examine predicted water surface topography for a steady‐state situation. The patterns are interpreted with respect to flow structure dynamics, visual observations of boils, and bed topography. Results indicate that coherent patterns emerge at the water surface of a discordant bed confluence for different flow conditions. The zone of stagnation and the mixing layer are characterized by super‐elevation, a lateral tilt is present at the edge of the mixing layer, and a zone of super‐elevation is present on the tributary side at the downstream junction corner. The latter seems associated with periodical upwelling and is not present in the numerical simulations that do not take into account instantaneous velocity fluctuations. Planform curvature, topographic steering related to the tributary mouth bar, and turbulent structures associated with the mixing layer all play a key role in the pattern of both the average and standard deviation of the water surface topography at confluences. Copyright © 2002 John Wiley & Sons, Ltd.
A stability criterion inherent in laws governing alluvial channel flow
Authors: Huang He Qing , Nanson Gerald C.
Published: August 2002

The stability criterion of maximum flow efficiency (MFE) has previously been found inherent in typical alluvial channel flow relationships, and this study investigates the general nature of this criterion using a wider range of flow resistance and bedload transport formulae. For straight alluvial channels, in which the effect of sediment sorting is insignificant, our detailed mathematical analysis demonstrates that a flow efficiency factor ε occurs generally as the ratio of sediment (bedload) discharge Qs to stream power Ω (γQS) in the form of $\def\endash{\hbox{--}}\def\lambdabar{{\mathchar'26\mkern-9mu\lambda}} {\varepsilon = {Q_{\rm s}}/ \Omega^{\lambdabar} (\lambdabar = 0{\cdot}86\endash 0{\cdot}88)}$. When ε is maximized (i.e. Qs is maximized or Ω is minimized), maximally efficient straight channel geometries derived from most flow resistance and bedload transport formulae are found compatible with observed bankfull hydraulic geometry relations. This study provides support for the use of the criteria of MFE, maximum sediment transporting capacity and minimum stream power for understanding the operation of alluvial rivers, and also addresses limitations to the direct application of its findings. Copyright © 2002 John Wiley & Sons, Ltd.
Flooding and geomorphic impacts in a mountain torrent: Raise Beck, central Lake District, England
Authors: Johnson R. M. , Warburton J.
Published: August 2002

Raise Beck is a mountain torrent located in the central Lake District fells, northern England (drainage area of 1·27 km2). The torrent shows evidence of several major flood events, the most recent of which was in January 1995. This event caused a major channel avulsion at the fan apex diverting the main flood flow to the south, blocking the A591 trunk road and causing local flooding. The meteorological conditions associated with this event are described using local rainfall records and climatic data. Records show 164 mm of rainfall in the 24 hours preceding the flood. The peak flood discharge is reconstructed using palaeohydrological and rainfall–runoff methods, which provide discharge values of 27–74 m3s−1, and 4–6 m3s−1, respectively. The flood transported boulders with b‐axes up to 1400 mm. These results raise some important general questions about flood estimation in steep mountain catchments. The geomorphological impact of the event is evaluated by comparing aerial photographs from before and after the flood, along with direct field observations. Over the historical timescale the impact and occurrence of flooding is investigated using lichenometry, long‐term rainfall data, and documentary records. Two major historical floods events are identified in the middle of the nineteenth century. The deposits of the recent and historical flood events dominate the sedimentological evidence of flooding at Raise Beck, therefore the catchment is sensitive to high magnitude, low frequency events. Following the 1995 flood much of the lower catchment was channelized using rip‐rap bank protection, re‐establishing flow north towards Thirlmere. The likely success of this management strategy in containing future floods is considered, based on an analysis of channel capacities. It is concluded that the channelization scheme is only a short‐term solution, which would fail to contain the discharge of an event equivalent to the January 1995 flood. Copyright © 2002 John Wiley & Sons, Ltd.
Vegetation influences on water yields from grassland and shrubland ecosystems in the Chihuahuan Desert
Authors: Neave Mel , Abrahams Athol D.
Published: August 2002

This study examines runoff generated under simulated rainfall on Summerford bajada in the Jornada Basin, New Mexico, USA. Forty‐five simulation experiments were conducted on 1 m2 and 2 m2 runoff plots on grassland, degraded grassland, shrub and intershrub environments located in grassland and shrubland communities. Average hydrographs generated for each environment show that runoff originates earlier on the vegetated plots than on the unvegetated plots. This early generation of runoff is attributed to soil infiltration rates being overwhelmed by the rapid concentration of water at the base of plants by stemflow. Hydrographs from the degraded grassland and intershrub plots rise continuously throughout the 30 min simulation events indicating that these plots do not achieve equilibrium runoff. This continuously rising form is attributed to the progressive development of raindrop‐induced surface seals. Most grassland and shrub plots level out after the initial early rise indicating equilibrium runoff is achieved. Some shrub plots, however, display a decline in discharge after the early rise. The delayed infiltration of water into macropores beneath shrubs with vegetation in their understories is proposed to explain this declining form. Water yields predicted at the community level indicate that the shrubland sheds 150 per cent more water for a given storm event than the grassland. Copyright © 2002 John Wiley & Sons, Ltd.
Discussion on 'Estimating depth‐averaged velocities in rough channels'
Authors: Ferro Vito , Carollo Francesco G.
Published: August 2002

In this short communication the four estimate criteria of the depth‐averaged local velocity proposed by Byrd et al. (Earth Surface Processes and Landforms, 2000, Vol. 25, pp. 167–173) are compared both with the three‐point method of Bathurst and with the average velocity obtained by integrating the velocity profile (FPa2) suggested by Ferro and Pecoraro (Water Resources Research, 2000, Vol. 36, pp. 2761–2770). The comparison was carried out using 84 velocity profiles measured by an acoustic Doppler velocimeter in a rectangular flume with a gravel bed. Copyright © 2002 John Wiley & Sons, Ltd.