bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal middle cerebral artery peak systolic velocity in the investigation of non‐immune hydrops
Authors: Hernandez‐Andrade E. , Scheier M. , Dezerega V. , Carmo A. , Nicolaides K. H. 
Published: March 2004

AbstractObjectiveIn some cases of non‐immune hydrops there is congenital or acquired fetal anemia. The aim of this study was to investigate the potential value of fetal middle cerebral artery peak systolic velocity (MCA‐PSV) in the assessment and management of non‐immune hydrops due to anemia.MethodsFetal MCA‐PSV and fetal hemoglobin concentration, in blood obtained by cordocentesis, were measured in 16 singleton pregnancies referred to our unit for further investigations because of a diagnosis of non‐immune hydrops fetalis. In all cases a detailed ultrasound examination demonstrated moderate or severe ascites, with or without skin edema, and pericardial or pleural effusions. Furthermore, there were no obvious malformations to account for the hydrops. In each fetus the measured MCA‐PSV and hemoglobin concentration were expressed as delta values (the difference in SD from the normal mean for gestation). Regression analysis was used to determine the significance of the association between delta MCA‐PSV and delta fetal hemoglobin concentration. In addition, we searched our database to identify the sonographic features and hemoglobin concentration of fetuses with congenital infection.ResultsIn the 16 cases of non‐immune hydrops there were seven with parvovirus B19 infection, one each of α‐thalassemia and primary cardiomyopathy and seven with no obvious explanation for the hydrops. There was a significant association between delta MCA‐PSV and delta hemoglobin concentration (delta hemoglobin = (delta MCA‐PSV + 0.1437)/−0.4154; R2 = 0.7202; P < 0.0001). In 10 of the cases the fetal hemoglobin concentration was more than 4 SD below the normal mean for gestation and in all these cases the MCA‐PSV was more than 2 SD above the normal mean for gestation. Our computer search identified an additional nine fetuses with parvovirus B19 infection and in all cases the predominant sonographic finding was ascites and the hemoglobin concentration was more than 4 SD below the normal mean. In contrast, only 3/14 fetuses with cytomegalovirus, toxoplasmosis, coxsackie B or Treponema infection had ascites and only 2/14 had a hemoglobin deficit of 4–6 SD.ConclusionIn the management of non‐immune hydrops, measurement of fetal MCA‐PSV can help identify the subgroup with fetal anemia. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Pre‐eclampsia and peripartum cardiomyopathy in molar pregnancy: clinical implication for maternally imprinted genes
Authors: Billieux M.‐H. , Petignat P. , Fior A. , Mhawech P. , Blouin J.‐L. , Dahoun S. , Vassilakos P. 
Published: March 2004

AbstractMolar pregnancies are associated with increased maternal complications, notably pre‐eclampsia, but peripartum cardiomyopathy has been rarely observed. Here we report on a 34‐year‐old woman, gravida 2 para 1, who presented to our obstetric clinic for routine screening at 16 weeks of gestation. Elevated maternal serum alpha‐fetoprotein and free beta‐human chorionic gonadotropin were observed. Amniocentesis revealed a triploid constitution (69,XXX) and ultrasound examination showed growth restriction, fetal anomalies, placentomegaly and a total placenta previa. On admission at 18 weeks' gestation, the patient developed vaginal bleeding and pre‐eclampsia. She underwent a Cesarean delivery and 6 h later developed congestive heart failure requiring intensive care support. Molecular analysis of the conceptus and parental DNA demonstrated an excess of paternal genomic contribution. The over‐representation of the paternal chromosome complement may support the role of genomic imprinting in the clinical course of this case. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Rotation‐rate continuity in bi‐axial plastic deformation
Authors: Bish R.L. 
Published: March 2004

AbstractThe hypothesis of rotation‐rate continuity, which is associated with the deformation of homogeneous, isotropic bodies by slip, is applied to the plastic flow of a cold‐worked metal (or strain‐aged mild‐steel) under the assumption of bi‐axial strain. In a special case, two classes of rotationally continuous slip‐line fields are shown to exist on curved principal surfaces. The first of these reduces to Hill's equiangular net under plane strain, further special cases of this field being the circular‐centred‐fan and the rectangual‐net. A second class of special solutions consists, again under plane‐strain, of two orthogonally intersecting families of logarithmic spirals. A slip‐line field that occurs in the drawing of a circular cup obeys this condition, as it applies to a curved principal surface. The general condition for continuity of rotation‐rate within a slip‐line net, located on a curved principal surface, is then derived and it is shown that Prandtl's solution to the plane‐strain compression problem obeys this general condition; except in a pair of thin layers adjacent to the platens.
Singularities in elasticity and their treatment with Fourier series
Authors: Nkemzi B. 
Published: March 2004

AbstractThis paper analyses the regularity of the weak solution of the linear elasticity system in three‐dimensional axisymmetric domains with reentrant edges under prescribed traction on the boundary by means of Fourier series. Using partial Fourier analysis with respect to one space direction (rotational angle), the three‐dimensional boundary value problem (BVP) is decomposed into a sequence of decoupled two‐dimensional boundary value problems on the meridian of the axisymmetric domain. The splitting of the 2D solutions near corners of the meridian domain into regular and singular parts provides coefficients from which the 3D edge singularity functions (generalized stress intensity factors) are derived. Two types of singularity functions are presented, namely, a tensorial type, which needs more smoothness assumption on the right hand side and a non‐tensorial type, which does not demand any further smoothness assumptions.
On the boundary conditions for EG methods applied to the two‐dimensional wave equation system
Authors: Lukáčová‐Medvid'ová M. , Warnecke G. , Zahaykah Y. 
Published: March 2004

AbstractThe subject of the paper is the study of several nonreflecting and reflecting boundary conditions for the evolution Galerkin (EG) methods which are applied for the two‐dimensional wave equation system. Different known tools are used to achieve this aim. Namely, the method of characteristics, the method of extrapolation, the Laplace transformation method, and the perfectly matched layer (PML) method. We show that the absorbing boundary conditions which are based on the use of the Laplace transformation lead to the Engquist‐Majda first and second order absorbing boundary conditions, see [3]. Further, following Bérenger [1] we consider the PML method. We discretize the wave equation system with the leap‐frog scheme inside the PML while the evolution Galerkin schemes are used inside the computational domain. Numerical tests demonstrate that this method produces much less unphysical reflected waves as well as the best results in comparison with other techniques studied in the paper.
Modelling in vehicle dynamics of automobiles
Authors: Lugner P. , Plöchl M. 
Published: March 2004

AbstractA general problem formulation and the resulting scheme of modelling dynamical system behaviour is introduced before a specification with respect to automobiles is done. An essential component for the vehicle behaviour is the tyre. Models of different complexity with respect to its mathematical‐mechanical formulation are presented. Simple models of the automobile itself allow a separation of longitudinal, lateral, and vertical dynamics and a partially analytical derivation of corresponding equations of motion. These models are usually also the approximations used for the design of a state observer and controller to influence the vehicle behaviour. For a more detailed representation of the vehicle 3D‐models are assembled by their individual components, e.g. suspensions, drive train, and steering system. In this way a good agreement between measurements and simulation results can be realized up to the nonlinear range of vehicle behaviour. Nowadays MBS‐models, established with professional software packages, are applied. They integrate all essential components, taking into account different linkages, e.g. bushings and joints. For component strength design, a rough road surface description can be implemented additionally. To improve by simulation the active safety or handling of the vehicle, these models represent the controlled complex vehicle in the global control loop whereas linearized models as mentioned above are applied for the controller design. As an example the design of an extended ESP‐controller and its consequences for severe braking conditions during cornering are discussed showing the necessary steps in modelling and their mathematical formulation.
A physical basis for fractional derivatives in constitutive equations
Authors: Pfitzenreiter T. 
Published: March 2004

AbstractIn good coincidence with experimental data the damping properties of viscoelastic media can be described by fractional derivatives. We present a model, which under certain assumptions on the interactions between macromolecules leads to a macroscopic stress strain relation with fractional derivatives in the damping term. For this purpose we use the Kubo formula of nonequilibrium thermodynamics.
Late‐season induction of diapause in Nezara viridula and its effect on adult coloration and post‐diapause reproductive performance
Authors: Musolin Dmitry L. , Numata Hideharu 
Published: March 2004

Abstract Nezara viridula (L.) (Heteroptera: Pentatomidae) recently expanded its distribution range in Japan and reached Osaka. In the southern temperate zone, the species overwinters in the adult stage and reproductive diapause is associated with a body colour change from green to russet. In Osaka, the reproductive diapause is only induced in September–October and nymphs from late egg masses are destined to die during winter. However, the fate of adults emerging late in the season remained unknown. Survival, body colour change, and post‐diapause reproduction were studied under quasi‐natural conditions in Osaka in 1999–2000 in those adults that attained adulthood as late as in November. Two experimental cohorts were used: in the Outdoor cohort, insects were reared outdoors starting in their second instar (28 September); in the Laboratory cohort, nymphs and subsequently adults were reared from the same day under diapause‐inducing conditions (L10:D14 at 25 °C), then acclimatized (5 days at 20 °C and 5 days at 15 °C; L10:D14) and transferred outdoors on 1 December. Adults in both cohorts did not reproduce in autumn and survived the winter with a low mortality. More than 20% of adults in the Outdoor cohort failed to change body colour from green to russet during winter, apparently because of the low ambient temperature, suggesting that the environmental conditions required for colour change do not completely coincide with those required for diapause induction, and that the colour of the adults is not always a reliable indicator of diapause in this species. After overwintering, females from the Outdoor cohort produced significantly fewer egg masses and eggs and had a significantly shorter period of oviposition than females that entered diapause under short‐day conditions in the Laboratory cohort. Thus, if progeny from the late egg masses attain adulthood late in the autumn, these adults have high chances of successful overwintering, but their reproductive output after the winter diapause is significantly reduced.
Characterization of a Bacillus thuringiensis strain with a broad spectrum of activity against lepidopteran insects
Authors: Martínez Clara , Porcar Manuel , López Alejandro , De Escudero Iñigo Ruiz , Pérez‐Llarena Francisco J. , Caballero Primitivo 
Published: March 2004

AbstractThe insect pathogen Bacillus thuringiensis is suitable for use in biological control, and certain strains have been developed as commercial bioinsecticides. The molecular and biological characterization of a Bacillus thuringiensis subsp. aizawai strain, named HU4‐2, revealed its potential as a bioinsecticide. The strain was found to contain eight different cry genes: cry1Ab, cry1Ad, cry1C, cry1D, cry1F, cry2, cry9Ea1, and a novel cry1I‐type gene. Purified parasporal crystals from strain HU4‐2 comprised three major proteins of 130–145 kDa, which were tested for their insecticidal potency to four species of Lepidoptera (Helicoverpa armigera, Spodoptera exigua, S. littoralis, and S. frugiperda) and three species of mosquito (Culex pipiens pipiens, Aedes aegypti, and Anopheles stephensi). The crystal proteins were highly toxic against all the species of Lepidoptera tested, moderately toxic against two of the mosquito species (C. pipiens and Ae. aegypti), but no toxicity was observed against a third species of mosquito (An. stephensi) at the concentrations used in our study. The LC50 values of the HU4‐2 Bt strain against H. armigera larvae (5.11 µg/ml) was similar to that of HD‐1 Bt strain (2.35 µg/ml), the active ingredient of the commercial product Dipel®. Additionally, the LC50 values of the HU4‐2 Bt strain against S. littoralis, S. frugiperda, and S. exigua (2.64, 2.22, and 3.38 µg/ml, respectively) were also similar to that of the Bt strain isolated from the commercial product Xentari® for the same three species of Spodoptera (1.94, 1.34, and 2.19 µg/ml, respectively). Since Xentari® is significantly more toxic to Spodoptera spp. than Dipel® and, reciprocally, Dipel® is significantly more toxic against H. armigera than Xentari®, we discuss the potential of the HU4‐2 strain to control all these important lepidopteran pests.
Competitive interactions between an exotic and a native ladybeetle: a field cage study
Authors: Hoogendoorn Marlijn , Heimpel George E. 
Published: March 2004

AbstractWe conducted field‐cage studies on the direct interactions between a coccinellid species native to North America, Coleomegilla maculata De Geer, and a species introduced from Asia, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). We compared the mortality and weight gain of larvae of both species in field cages that enclosed one or both species with corn plants containing high or low aphid numbers. We did not find a significant effect of the presence of H. axyridis on the survival or weight gain of C. maculata, but H. axyridis larvae weighed more when kept with C. maculata for 5 days than when kept with equal numbers of conspecifics. This suggests that intraspecific competition was stronger for H. axyridis than the interspecific competition with C. maculata. The spatial distribution of C. maculata over the plants differed between single‐species and two‐species treatments in a manner that suggested that this species avoided interactions with H. axyridis.
Kingsley Laffer Memorial Lecture
Authors: Lansbury Russell D. 
Published: March 2004

Despite rising levels of prosperity in Australia in recent decades, there is growing economic and social inequality. Many people are working longer hours and more intensively in insecure jobs. Australia has one of the highest levels of casual employment in the industrialised world. Stress at work is one of the major causes of occupational illness. A more decentralised system of industrial relations has contributed to this situation by removing many of the previous safeguards that workers had under awards and agreements. This is exemplified by a number of award-based employment arrangements related to various forms of leave (e.g. sick leave and maternity leave) which have been ‘traded off’ in enterprise agreements, often without union involvement or worker representation. This process has been assisted by the federal government’s legislative reforms which have been hostile to unions and have contributed to a decline in unionisation. The government has also weakened the powers of the Australian Industrial Relations Commission to protect workers whose bargaining power is weak. Many of those who advocate an even more deregulated and individualised form of industrial relations for Australia argue that the forces of globalisation provide no alternative. Yet other countries, particularly in northern Europe, have retained strong labour market institutions to provide adequate social protection while competing effectively in the international economy. Indeed, rather than seeing globalisation as a threat, Australia should be supporting the efforts of international agencies, such as the International Labour Organisation, to assist other small nations to strengthen the rights of their citizens in the workplace and labour market. To ensure that Australia remains both a prosperous and an equitable society, we need a new social contract or partnership between employers, workers, unions, community, organisations and government. The three pillars of a new social contract comprisepolicies that are well established in many of the advanced industrialised societies. The first pillar is an active labour market policy that has been long advocated by the Organisation for Economic Cooperation and Development (OECD) and would see resources invested in job creation rather than job reduction. The second pillar is the rebuilding of Australia’s skills and intellectual capital by encouraging greater investment in training and development of the workforce. The third pillar is the establishment of a national superannuation system to ensure both universal coverage and secure entitlements. To achieve these goals, the federal government must develop a comprehensive industrial relations policy that involves greater regulation of the labour market and restoration of labour market institutions to ensure more equitable wages and working conditions. These measures are required to ensure that economic efficiency is achieved without undermining social equity, which is the basis of democratic society.
QUERCETIN, AN ANTI‐OXIDANT BIOFLAVONOID, ATTENUATES DIABETIC NEPHROPATHY IN RATS
Authors: Anjaneyulu Muragundla , Chopra Kanwaljit 
Published: March 2004

SUMMARY1. Diabetic nephropathy is an important microvascular complication and one of the main causes of end‐stage renal disease. Many in vivo and in vitro studies have indicated that oxidative stress is one of the major pathophysiological mechanisms involved in the development of diabetic nephropathy. In the present study, we examined the effect of an anti‐oxidant bioflavonoid quercetin on renal function and oxidative stress in streptozotocin (STZ)‐induced diabetic rats.2. Diabetes was induced in Sprague‐Dawley rats with a single intravenous injection of STZ (45 mg/kg). Four weeks after STZ injection, quercetin (10 mg/kg per day) was given orally for 4 weeks in both control and diabetic rats. Plasma glucose levels and bodyweights were measured at 4 and 8 weeks after the STZ injection. At the termination of the experiments, urine albumin excretion, urine output, serum creatinine, blood urea nitrogen, creatinine and urea clearance were measured. The renal oxidative stress marker malonaldehyde, glutathione levels and the anti‐oxidant enzymes superoxide dismutase and catalase were measured in kidney homogenate.3. Streptozotocin‐injected rats showed significant increases in blood glucose, polyuria, proteinuria and a decrease in bodyweight compared with age‐matched control rats. After 8 weeks, diabetic rats exhibited renal dysfunction, as evidenced by reduced creatinine and urea clearance, and proteinuria along with a marked increase in oxidative stress, as determined by lipid peroxidation and activities of key anti‐oxidant enzymes. Treatment with quercetin significantly attenuated renal dysfunction and oxidative stress in diabetic rats.4. These results confirm the role of oxidative stress in the development of diabetic nephropathy and point to the possible anti‐oxidative mechanism being responsible for the nephroprotective action of quercetin.
INCREASED SUSCEPTIBILITY OF VENTRICULAR ARRHYTHMIAS TO ACONITINE IN ANAESTHETIZED RATS IS ATTRIBUTED TO THE INHIBITION OF BAROREFLEX
Authors: Shu He , Yi‐Ming Wuliya , Xu Li‐Ping , Miao Chao‐Yu , Su Ding‐Feng 
Published: March 2004

SUMMARY1. Aconitine is widely used to produce ventricular arrhythmias in anaesthetized rats. The present work was designed to test the hypothesis that anaesthesia may increase the susceptibility of ventricular arrhythmia to aconitine due to the inhibition of arterial baroreflex. In addition, the susceptibility of ventricular arrhythmia to aconitine at different times during the course of a whole day was also investigated.2. Male Sprague‐Dawley rats were used. Arrhthymias were induced by aconitine infusion at six time points (01.00, 05.00, 09.00, 13.00, 17.00 and 21.00 h) with rats in both anaesthetized and conscious states. In sinoaortic‐denervated (SAD) rats, ventricular arrhythmias were induced by aconitine infusion between 09.00 and 13.00 h.3. There was a significant difference in the lethal dose of aconitine between anaesthetized and conscious rats (99.6 ± 30.1 vs 58.2 ± 14.7 µg/kg; P < 0.001). Anaesthesia did increase the susceptibility of rats to ventricular arrhythmias following aconitine.4. In SAD rats, the lethal dose of aconitine was less than that for baroreflex‐intact rats when determined in the conscious state. The difference in the lethal dose of aconitine between SAD and baroreflex‐intact rats disappeared when it was determined in anaesthetized rats.5. The time of day did not affect the susceptibility of either anaesthetized or conscious rats to ventricular arrhythmias following aconitine, except for a difference in the ventricullar fibrillation threshold dose between 13.00 and 17.00 h in anaesthetized rats.6. In conclusion, anaesthesia may increase the risk of ventricular arrhythmias following aconitine. Intact arterial baroreflex function is necessary to prevent drug‐induced ventricular arrhythmias.
The use of models and methods for strategic planning: Towards an holistic view of strategy
Authors: Philpott E. , Hamblin D. J. , Baines T. , Kay G. 
Published: March 2004

AbstractFormulating manufacturing business strategy is often fragmented in as much as current tools address upstream and downstream vertical integration with product integration, or more recently, product and infrastructure integration. Rarely do tools address all of these dimensions in an holistic manner. The research described in this paper is that undertaken in the MAPSTRAT project: a scoping study with industrial partners, aiming to satisfy this business need. A comprehensive literature study is described which is contextualized using six case studies. The paper stresses the importance of ‘joined‐up thinking’ and outlines plans for an appropriate tool that is under development.
Teaching meta‐heuristics within virtual learning environments
Authors: Reiners T. , Voß S. 
Published: March 2004

AbstractModern education of operations research and management science (OR/MS) can greatly benefit from interactive learning methods in order to build and develop modeling and problem‐solving skills. In this paper we consider the teaching of meta‐heuristics as an important part of OR/MS with significant recent interest. We discuss possibilities of supporting the teaching of meta‐heuristics such as simulated annealing or tabu search through interactive learning. The paper also presents a survey of some relevant issues within VORMS (Virtual Operations Research/Management Science), a project currently undertaken at six universities within Germany, and provides a presentation of the advances regarding the teaching of meta‐heuristics within this project. Further ideas refer to incorporating hotframe, a heuristic optimization framework, into the virtual learning environment.