bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of the bumping height on the performance of flip‐chipped CPW Lange couplers
Authors: Carchon G. , Nauwelaers B.
Published: August 2002

The influence of the bumping height on the performance of flip‐chipped CPW Lange couplers is investigated. The coupler design method is done by measurements of a coupler integrated in a multilayer thin‐film MCM‐D. The reasons for the detuning are identified, and solutions to easily predistort the design or reduce the detuning effect are given. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 263–267, 2001.
Implementing OSMEI on 3‐D arbitrary conducting objects
Authors: Liu Yaowu , Liu Wanming , Mei K. K.
Published: August 2002

A sparse technique for the dense matrix of the method of moments (MoM) is implemented to the electromagnetic scattering of a 3‐D arbitrary conducting object for the first time. The numerical examples for the plane‐wave scattering of a conducting sphere with 0.2 and 0.4λ show that the surface current densities of OSMEI and MoM agree well. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 273–276, 2001.
Improvement of the hybrid moment method–physical optics method through a novel evaluation of the physical optics operator
Authors: Taboada J. M. , Obelleiro F. , Rodríguez J. L.
Published: August 2002

This paper presents an alternative procedure for the evaluation of the physical optics (PO) contribution into a hybrid moment method–physical optics (MM–PO) code. The proposed formulation includes a linear interpolation of the phase over large triangular subdomains for the PO regions, where the radiated field can be analytically determined. This allows a drastic reduction of the computational cost, while maintaining or even improving the degree of accuracy. In this way, the scope of application of the MM–PO hybrid code is enhanced to larger problems in terms of wavelength. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 357–363, 2001.
Permittivity profile inversion of a one‐dimensional medium using the fractional linear transformation and the phase compensation constant
Authors: Song Choongho , Lee Sangseol
Published: August 2002

A novel reconstruction method of a one‐dimensional medium from information contained in the frequency‐domain reflection coefficient is considered. An approximate formula produced by applying a fractional linear transformation (FLT) to the nonlinear Riccati differential equation is used. The phase compensation constant (PCC) is introduced in order to reduce the phase error of the reconstructed permittivity profile of a discontinuous medium. Finally, the effective error reduction in the reconstructed profiles is shown by examples, which demonstrate the validity of this method. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 10–13, 2001.
De‐embedding PCB fixtures for package characterization
Authors: Wartenberg Scott A. , Grajek Phillip
Published: August 2002

Device characterization hinges on precise measurements of the device under test (DUT). When it cannot be probed directly, mount the package to a PCB fixture. While this makes measurement easy, separating the effects of the DUT from the PCB carrier can be difficult. This paper illustrates a method of de‐embedding the packageS‐parameters from those of the PCB. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 111–112, 2001.
Analysis of handwriting of children during treatment for acute lymphoblastic leukemia
Authors: Reinders‐Messelink H.A. , Schoemaker M.M. , Snijders T.A.B. , Göeken L.N.H. , Bökkerink J.P.M. , Kamps W.A.
Published: August 2002

Background

Children treated for acute lymphoblastic leukemia (ALL) often complain about handwriting problems.

Procedure

Using a computerized writing task, we have prospectively studied the processes necessary for the production of handwriting movements in 11 children (5–12 years old) during treatment for ALL. Children were tested at time points closely related to the vincristine administration.

Results and Conclusions

Children treated for ALL drew slower, with longer pause durations and increased drawing pressure. Children were able to overcome the problems, except for a consistently increased drawing pressure. This increased drawing pressure may be an attempt of the children to obtain sufficient kinesthetic information and thus can be seen as an adequate adaptation mechanism in case of peripheral neuropathy due to the neurotoxic effects of vincristine. However, neurotoxic effects of other cytostatic drugs cannot be excluded. Med Pediatr Oncol 2001;37:393–399. © 2001 Wiley‐Liss, Inc.
Cysteine, glutathione, and percoll treatments improve porcine oocyte maturation and fertilization in vitro*
Authors: Jeong Byeong‐Seon , Yang Xiangzhong
Published: August 2002

Several factors have been examined to improve in vitro fertilization and development of porcine oocytes. Cysteine is known to be beneficial for oocyte maturation and male pronuclear formation in pigs and glutathione is known to help prevent membrane disruption of sperm in other species, including human. It has also been reported that the presence of cumulus cells influences the outcome of in vitro fertilization in cattle. The objectives of the present study were to investigate the effects of several factors involved in porcine in vitro maturation (IVM) and fertilization (IVF) procedures on oocyte embryogenic competence. The following factors were examined: the effects of different concentrations (0, 0.285, 0.57, 1.14, 2.28 µM) and exposure duration (22 and 44 hr) of cysteine during IVM, glutathione inclusion and of cumulus presence during IVF, and the use of gradient Percoll (45%/90%) during sperm preparation. The presence of cysteine in maturation medium improved blastocyst development significantly regardless of the duration of exposure when compared to the control (11–16% vs. 4%, P < 0.01). However, no dose‐responsive effect was observed at the concentrations tested. The use of gradient Percoll during sperm preparation significantly improved cleavage (85% vs. 57%, P < 0.01) and blastocyst development (24% vs. 6%, P < 0.01) over conventional sperm preparation. Significant improvement was also achieved by the addition of glutathione to Percoll gradient (30% vs. 20%, P < 0.05). In conclusion, cysteine and glutathione as well as Percoll and cumulus were beneficial to embryogenic competence of porcine oocytes in this study. Mol. Reprod. Dev. 59:330–335, 2001. © 2001 Wiley‐Liss, Inc.
Gonadotropin‐releasing hormone agonist affects rat ovarian follicle development by interfering with FSH and growth factors on the prevention of apoptosis
Authors: Parborell F. , Dain L. , Tesone M.
Published: August 2002

Apoptosis is the biological process by which follicular cells are eliminated in atretic follicles. The aim of the present study was to examine the in vitro effect of a GnRH‐a (leuprolide acetate, LA) and its interactions with FSH, dibutyryl cAMP, and growth factors (IGF‐I, EGF, and FGF) on follicular apoptosis in early antral ovarian follicles obtained from prepubertal DES‐ treated rats. Follicles cultured 24 hr in the absence of hormones showed spontaneous onset of apoptotic DNA fragmentation. The presence of FSH suppressed the spontaneous onset of apoptotic DNA fragmentation (75–85%). Quantitative estimation of DNA cleavage from ovarian follicles revealed no significant changes in DNA fragmentation after in vitro LA treatment (1–100 ng/ml). However, coincubation with LA interfered partially with the effects of FSH on apoptosis suppression. This apoptosis suppression was also obtained by treatment with dibutyryl cAMP (80%), and was partially prevented by the presence of LA in the cultures. Follicles were cultured 24 hr with FGF, EGF, or IGF‐I, and these factors suppressed DNA fragmentation (70, 60, and 70% respectively), while the presence of LA (100 ng/ml) in the culture medium prevented this effect. In conclusion, we show that the rescue from apoptotic DNA fragmentation produced in early antral follicles by FSH, cAMP, and growth factors, is prevented by coincubation with LA. This GnRH analog would thus interfere in the pathway of FSH, cAMP and/or growth factors by an as yet unknown mechanism. Mol. Reprod. Dev. 60: 241–247, 2001. © 2001 Wiley‐Liss, Inc.
Accumulation of cytoplasmic lipid droplets in bovine embryos and cryotolerance of embryos developed in different culture systems using serum‐free or serum‐containing media
Authors: Abe Hiroyuki , Yamashita Shoko , Satoh Takeshi , Hoshi Hiroyoshi
Published: August 2002

In this study, the quantitative fluctuation of cytoplasmic lipid droplets (LD) and cryotolerance were investigated in bovine embryos derived from in vitro‐matured (IVM) and in vitro‐fertilized (IVF) oocytes developed in different culture systems using serum‐free or serum‐containing media. The serum‐free cultures were grown using IVMD101 medium in conjunction with bovine cumulus/granulosa cell (BCGC) cocultures or IVD101 medium without BCGC cocultures, and the serum‐containing cultures were grown in the presence of BCGC cocultures using HPM199 medium supplemented with 5% calf serum (HPM199 + CS). Large numbers of sudanophilic LD were present in the cytoplasm of bovine embryos from 2‐cell to hatched blastocyst stages, and the number and size differed between the embryos cultured in serum‐free and serum‐supplemented media. In the embryos cultured in HPM199 + CS, large (2–6 μm in diameter) sudanophilic LD increased significantly from the morula to the blastocyst stages. Throughout the embryonic development, the embryos developed in serum‐free cultures with and without BCGC cocultures had numerous sudanophilic LD, but most of these droplets were small (<2 μm in diameter) and large LD were less numerous than those embryos cultured in HPM199 + CS. Giant LD (>6 μm in diameter) were frequently observed in morulae and blastocysts (including early blastocysts) developed in HPM199 + CS. Electron microscopic observations demonstrated that large LD were abundant in the cytoplasm of trophoblast and embryonic (inner cell mass) cells of blastocysts cultured in HPM199 + CS. These large LD were identified as osmophilic LD, an indication that these lipid inclusions contained a significant proportion of unsaturated lipids. Many elongated mitochondria were found in embryos developed in IVMD101 and IVD101 at the morula and early blastocyst stages, whereas many of the mitochondria in the morulae developed in HPM199 + CS were of an immature form such as spherical or ovoid shape. The survival and hatching rates of embryos (morulae, early blastocysts, and blastocysts) produced in serum‐free media (both IVMD101 and IVD101) after post‐thaw culture were superior to those of embryos produced in serum‐containing medium. These results showed that bovine embryos cultured in serum‐containing medium abnormally accumulated cytoplasmic lipids into their cytoplasm and the excess accumulation of cytoplasmic LD in embryos may affect the cryotolerance of embryos. Mol. Reprod. Dev. 61: 57–66, 2002. © 2002 Wiley‐Liss, Inc.
Neuroprogressive disease of post‐infectious origin: A review of a resurging subacute sclerosing panencephalitis (SSPE)
Authors: Dyken Paul Richard
Published: August 2002

Subacute sclerosing panencephalitis (SSPE) is a progressive, essentially untreatable, disease of the nervous system. When first described in the 20th Century, it was characterized more for its neuropathological features than for its pathophysiology or cause. It was not until the 1960s that a clear relationship to the measles virus was established. It is now thought that this uncommon infectious encephalopathy is caused by a “slow,” altered or persistent form of the wild measles virus which has harbored in the nervous system for years. Then a “breakout” occurs and the more lytic and virulent organisms produce the progressive and spreading inflammatory and destructive lesions which are confined to the nervous system. Epidemiological study of the disease confirms its relationship to measles. In the years since the development of national measles immunization programs, there has been a dramatic decline in the incidence of measles exanthem and until recently a corresponding decline in the incidence of SSPE. In recent years there has been a mild to moderate increase in cases of SSPE as reported to the USA/International SSPE Registry. As yet, there has not been a totally effective treatment. The purpose of this paper is to give an overall review on SSPE and its relationship to measles. This review will include a prospectus of its history, considerations as to its etiology, correlation of clinicopathological features, and thoughts on the past and present epidemiology and treatment. MRDD Research Reviews 2001;7:217–225. © 2001 Wiley‐Liss, Inc.
On T2‐shortening by strongly magnetized spheres: A partial refocusing model
Authors: Gillis Pierre , Moiny Francis , Brooks Rodney A.
Published: August 2002

Computer simulations of water transverse relaxation induced by superparamagnetic particles are shown to disagree with the available theories, covering the slow diffusion domain. Understanding these new simulations, not in the slow diffusion domain, thus requires a new theoretical approach. A “partial refocusing model” is introduced for this purpose; it is based on a spatial division between an inner region where the gradients are too strong for the refocusing pulses to be efficient and an outer region where they are efficient. This model agrees with published simulations of relaxation induced by magnetic dipoles approximated as points. The validity domains of the various models are also compared. Magn Reson Med 47:257–263, 2002. © 2002 Wiley‐Liss, Inc.
Biexponential transverse relaxation (T2) of the proton MRS creatine resonance in human brain
Authors: Ke Y. , Cohen B.M. , Lowen S. , Hirashima F. , Nassar L. , Renshaw P.F.
Published: August 2002

Differences in proton MRS T2 values for phosphocreatine (PCr) and creatine (Cr) methyl groups (3.0 ppm) were investigated in studies of phantoms and human brain. Results from phantom studies revealed that T2 of PCr in solution is significantly shorter than T2 of Cr. Curve‐fitting results indicated that the amplitude‐TE curves of the total Cr resonance at 3.0 ppm in human brain (N = 26) fit a biexponential decay model significantly better than a monoexponential decay model (P < 0.006), yielding mean T2 values of 117 ± 21 ms and 309 ± 21 ms. Using a localized, long‐TE (272 ms) point‐resolved spectroscopy (PRESS) proton MRS during 2 min of photic stimulation (PS), an increase of 12.1% ± 3.5% in the mean intensity of the total Cr resonance in primary visual cortex (VI) was observed at the end of stimulation (P < 0.021). This increase is consistent with the conversion of 26% of PCr in VI to Cr, which is concordant with 31P MRS findings reported by other investigators. These results suggest a significantly shorter T2 for PCr than for Cr in vivo. This difference possibly could be exploited to quantify regional activation in functional spectroscopy studies, and could also lead to inaccuracies in some circumstances when the Cr resonance is used as an internal standard for 1H MRS studies in vivo. Magn Reson Med 47:232–238, 2002. © 2002 Wiley‐Liss, Inc.
Image‐based EPI ghost correction using an algorithm based on projection onto convex sets (POCS)
Authors: Lee K.J. , Barber D.C. , Paley M.N. , Wilkinson I.D. , Papadakis N.G. , Griffiths P.D.
Published: August 2002

This work describes the use of a method, based on the projection onto convex sets (POCS) algorithm, for reduction of the N/2 ghost in echo‐planar imaging (EPI). In this method, ghosts outside the parent image are set to zero and a model k‐space is obtained from the Fourier transform (FT) of the resulting image. The zeroth‐ and first‐order phase corrections for each line of the original k‐space are estimated by comparison with the corresponding line in the model k‐space. To overcome problems of phase wrapping, the first‐order phase corrections for the lines of the original k‐space are estimated by registration with the corresponding lines in the model k‐space. It is shown that applying these corrections will result in a reduction of the ghost, and that iterating the process will result in a convergence towards an image in which the ghost is minimized. The method is tested on spin‐echo EPI data. The results show that the method is robust and remarkably effective, reducing the N/2 ghost to a level nearly comparable to that achieved with reference scans. Magn Reson Med 47:812–817, 2002. © 2002 Wiley‐Liss, Inc.
Pulsed Z‐spectroscopic imaging of cross‐relaxation parameters in tissues for human MRI: Theory and clinical applications
Authors: Yarnykh Vasily L.
Published: August 2002

A new method of pulsed Z‐spectroscopic imaging is proposed for in vivo visualization and quantification of the parameters describing cross‐relaxation between protons with liquid‐like and solid‐like relaxation properties in tissues. The method is based on analysis of the magnetization transfer (MT) effect as a function of the offset frequency and amplitude of a pulsed off‐ resonance saturation incorporated in a spoiled gradient‐echo MRI pulse sequence. The theoretical concept of the method relies on an approximated analytical model of pulsed MT that provides a simple three‐parameter equation for a pulsed steady‐state Z‐spectrum taken far from resonance. Using this model, the parametric images of cross‐relaxation rate constant, content, and T2 of the semisolid proton fraction can be reconstructed from a series of MT‐weighted images and a coregistered T1 map. The method was implemented on a 0.5 T clinical MRI scanner, and it provided high‐quality 3D parametric maps within an acceptable scanning time. The estimates of cross‐relaxation parameters in brain tissues were shown to be quantitatively consistent with the literature data. Clinical examples of the parametric images of human brain pathologies (multiple sclerosis and glioma) demonstrated high tissue contrast and clear visualization of the lesions. Magn Reson Med 47:929–939, 2002. © 2002 Wiley‐Liss, Inc.
Imaging brain function in humans at 7 Tesla
Authors: Yacoub Essa , Shmuel Amir , Pfeuffer Josef , Van De Moortele Pierre‐Francois , Adriany Gregor , Andersen Peter , Vaughan J. Thomas , Merkle Hellmut , Ugurbil Kamil , Hu Xiaoping
Published: August 2002

This article describes experimental studies performed to demonstrate the feasibility of BOLD fMRI using echo‐planar imaging (EPI) at 7 T and to characterize the BOLD response in humans at this ultrahigh magnetic field. Visual stimulation studies were performed in normal subjects using high‐resolution multishot EPI sequences. Changes in R arising from visual stimulation were experimentally determined using fMRI measurements obtained at multiple echo times. The results obtained at 7 T were compared to those at 4 T. Experimental data indicate that fMRI can be reliably performed at 7 T and that at this field strength both the sensitivity and spatial specificity of the BOLD response are increased. This study suggests that ultrahigh field MR systems are advantageous for functional mapping in humans. Magn Reson Med 45:588–594, 2001. © 2001 Wiley‐Liss, Inc.
Imaging longitudinal cardiac strain on short‐axis images using strain‐encoded MRI
Authors: Osman Nael F. , Sampath Smita , Atalar Ergin , Prince Jerry L.
Published: August 2002

This article presents a new method for measuring longitudinal strain in a short‐axis section of the heart using harmonic phase magnetic resonance imaging (HARP‐MRI). The heart is tagged using 1‐1 SPAMM at end‐diastole with tag surfaces parallel to a short‐axis imaging plane. Two or more images are acquired such that the images have different phase encodings in a direction orthogonal to the image plane. A dense map of the longitudinal strain can be computed from these images using a simple, fast computation. Simulations are conducted to study the effect of noise and the choice of out‐of‐plane phase encoding values. Longitudinal strains acquired from a normal human male are shown. Magn Reson Med 46:324‐334, 20001. © 2001 Wiley‐Liss, Inc.
MR‐derived cerebral blood volume maps: Issues regarding histological validation and assessment of tumor angiogenesis
Authors: Pathak Arvind P. , Schmainda Kathleen M. , Ward B. Douglas , Linderman J.R. , Rebro Kelly J. , Greene Andrew S.
Published: August 2002

In an effort to develop MRI methods for the evaluation of tumor angiogenesis (new blood vessel formation), MRI‐derived cerebral blood volume (CBV) information has been compared to histologic measures of microvessel density (MVD). Although MVD is a standard marker of angiogenesis, it is not a direct correlate of the volume measurements made with MRI, and therefore inappropriate for the development and validation of the MR techniques. Therefore, the goal of this study was to develop an approach by which MR measurements of CBV can be directly correlated. To this end, dynamic susceptibility contrast (DSC) MRI experiments were performed in six Fisher rats implanted with 9L gliosarcoma brain tumors. Subsequently, the circulation was perfused with a latex compound (Microfil®), after which 50‐μm tissue sections were analyzed for vessel count, diameter, and the fraction of area comprised of vessels. The results demonstrate that while fractional area (FA) does not provide a good measure of CBV, FA corrected for section thickness effects does. Whereas the FA in normal brain was found to be 13.03 ± 1.83% the corrected FA, or fractional volume (FV), was 1.89 ± 0.39%, a value in agreement with those reported in the literature for normal brain. Furthermore, while no significant difference was found between normal brain and tumor FA (P = 0.55), the difference was significant for FV (P = 0.036), as would be expected. And only with FV does a correlation with the MRI‐derived CBV become apparent (rS = 0.74). There was strong correlation (rs = 0.886) between the tumor / normal blood volume ratios as estimated by each technique, although the MR‐ratio (1.56 ± 0.29) underestimated the histologic‐ratio (2.35 ± 0.75). Thus, the correlation of MRI CBV methods requires a measurement of fractional vessel area and correction of this area for section thickness effects. This new independent correlative measure should enable efficient and accurate progress in the development of MRI methods to evaluate tumor angiogenesis. Magn Reson Med 46:735–747, 2001. © 2001 Wiley‐Liss, Inc.
Localized bioimpedance analysis in the evaluation of neuromuscular disease
Authors: Rutkove Seward B. , Aaron Ronald , Shiffman Carl A.
Published: August 2002

Localized bioimpedance analysis is a novel, noninvasive technique with potential application to neuromuscular disease. In this procedure, high‐frequency alternating current is passed through muscle, and parameters related to the consequent voltage pattern are evaluated. Currents flowing perpendicular to muscle fibers encounter many more cell membranes than do currents flowing parallel to them, producing surface voltage patterns that are altered by disease. Using this technique, 45 normal subjects and 25 patients with various neuromuscular diseases were studied, including 4 with amyotrophic lateral sclerosis, 4 with inflammatory myopathy, and 11 with inclusion‐body myositis. Two parameters, the spatially averaged phase and the effective longitudinal resistivity, were altered in patients with neuromuscular disease. Reductions in phase correlated to disease progression, whereas normalization of phase correlated with disease remission. In patients with inclusion‐body myositis, a unique pattern of reduced phase and elevated resistivity was identified. These findings suggest that localized bioimpedance analysis has the potential of playing a substantial role in the diagnostic and therapeutic evaluation of neuromuscular disease. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Rhabdomyolysis: A review
Authors: Warren Jason D. , Blumbergs Peter C. , Thompson Philip D.
Published: August 2002

Rhabdomyolysis, a syndrome of skeletal muscle breakdown with leakage of muscle contents, is frequently accompanied by myoglobinuria, and if sufficiently severe, acute renal failure with potentially life‐threatening metabolic derangements may ensue. A diverse spectrum of inherited and acquired disorders affecting muscle membranes, membrane ion channels, and muscle energy supply causes rhabdomyolysis. Common final pathophysiological mechanisms among these causes of rhabdomyolysis include an uncontrolled rise in free intracellular calcium and activation of calcium‐dependent proteases, which lead to destruction of myofibrils and lysosomal digestion of muscle fiber contents. Recent advances in molecular genetics and muscle enzyme histochemistry may enable a specific metabolic diagnosis in many patients with idiopathic recurrent rhabdomyolysis. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Human muscle protein degradation in vitro by eosinophil cationic protein (ECP)
Authors: Sugihara Rie , Kumamoto Toshihide , Ito Tomoko , Ueyama Hidetsugu , Toyoshima Itaru , Tsuda Tomiyasu
Published: August 2002

To clarify the role of tissue eosinophils in and around inflammatory foci, we purified eosinophil cationic protein (ECP) and examined its effect on muscle protein degradation in vitro. Eosinophil cationic protein was purified from the buffy coat of blood from healthy volunteers. Myofibrillar, soluble sarcoplasmic, and membrane‐associated cytoskeletal proteins were fractionated from latissimus dorsi muscle obtained by orthopedic procedures done on a patient with no neurologic abnormalities. After incubation of these fractions with purified ECP, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE) and immunoblotting were performed. Eosinophil cationic protein degraded the myofibrillar proteins, especially the myosin heavy chain (MHC) and α‐actinin. It also degraded membrane‐associated cytoskeletal proteins dystrophin and spectrin, whereas soluble sarcoplasmic proteins did not undergo proteolysis. Quantitative analysis of the MHC degradation showed that the ECP reaction was dose‐dependent and that the optimal pH was 7.0. Protein degradation was not inhibited by heparin or the protease inhibitors leupeptin, E‐64, and pepstatin A. Our results suggest that ECP functions in the degradation of myofibrillar and membrane‐associated cytoskeletal proteins, indicating that tissue eosinophils have a specific role in muscle fiber degradation in some myopathies associated with numerous tissue eosinophils, such as eosinophilic myositis, eosinophilic myalgia syndrome, and eosinophilic endocardial disease. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1627–1634, 2001
A fully coupled hydro‐thermo‐poro‐mechanical model for black oil reservoir simulation
Authors: Pao W. K. S. , Lewis R. W. , Masters I.
Published: August 2002

A fully coupled formulation of a hydro‐thermo‐poro‐mechanical model for a three‐phaseblack oilreservoir model is presented. The model is based upon the approach proposed by one of the authors which fully couples geomechanical effects to multiphase flow. Their work is extended here to include non‐isothermal effects. The gas phase contribution to the energy equation has been neglected based on a set of assumptions. The coupled formulation given herein differs in several ways when compared to the earlier work and an attempt is made to link the flow based formulation and mixture theory. The Finite Element Method is employed for the numerical treatment and essential algorithmic implementation is discussed. Numerical examples are presented to provide further understanding of the current methodology. Copyright © 2001 John Wiley & Sons, Ltd.
Structural features and mechanical behaviour of a pyroclastic weak rock
Authors: Cecconi Manuela , Viggiani Giulia MB
Published: August 2002

The results of an extensive programme of laboratory testing on intact and reconstituted samples of a pyroclastic weak rock from the volcanic complex of the Colli Albani (Central Italy) are presented. The deposit is known asPozzolana Neraand may be assimilated to a bonded coarse grained material. The nature of bonds and the micro‐structural features were examined by means of diffractometry, optical and electron microscopy. As bonds are made of the same constituents of grains and aggregates of grains, bond deterioration and particles breakage upon loading are indistinguishable features of the mechanical behaviour. The testing programme consisted mainly of one‐dimensional and drained and undrained triaxial compression tests in a wide range of confining pressures up to 58 MPa. As confining stress increases, the mechanical behaviour of the material changes from brittle and dilatant to ductile and contractant; for both brittle and ductile behaviour failure is associated with the formation of shear surfaces separating the sample in several parts at the end of test. The experimental stress–dilatancy relationships are compared with the classical stress–dilatancy theories for a purely frictional material and for a material with friction and cohesion between particles. The analysis of the data indicates that peak strength results from the interplay between degradation of inter‐particle bonds, increasing friction between particles and increasing rate of dilation. Copyright © 2001 John Wiley & Son, Ltd.
Urinary incontinence symptom scores and urodynamic diagnoses
Authors: FitzGerald Mary P. , Brubaker Linda
Published: August 2002

The aim of this study was to determine whether scores on two validated urinary incontinence symptom scales predicted eventual urodynamic diagnoses. Two hundred ninety‐three patients undergoing multi‐channel urodynamic testing rated their symptoms of urinary incontinence and/or pelvic organ prolapse (POP), using the Incontinence Impact Questionnaire, the Urogenital Distress Inventory, and an obstructive symptom subscale from the long form of the Incontinence Impact Questionnaire. Among the 202 (69%) patients without advance‐stage POP, increasing scores on scale items related to stress and urge incontinence predicted increasing frequency of the diagnoses of genuine stress incontinence (GSI) and detrusor instability, respectively. Among the 91 (31%) patients with advance‐stage POP, there was no association. Among all patients with GSI, the presence of intrinsic sphincter deficiency could not be predicted by responses to the symptom scales. Scores on the symptom scales were inadequate predictors of eventual urodynamic diagnoses, especially among women with advance‐stage POP. Neurourol. Urodynam. 21:30–35, 2002. © 2002 Wiley‐Liss, Inc.
Senile plaques do not induce susceptibility effects in T2*‐weighted MR microscopic images
Authors: Dhenain Marc , Privat Nicolas , Duyckaerts Charles , Jacobs Russell E.
Published: August 2002

Senile plaques are the hallmarks of Alzheimer's disease. They typically range from 16 to 150 µm in size with most less than 25 µm. Mechanisms by which they might affect MR contrast and thus be made visible in this imaging modality are still unknown. Plausibility studies suggested that they might have a different magnetic susceptibility than surrounding tissue. A large difference would cause the plaque and a relatively large volume of adjacent tissue to be hypo‐intense in T2*‐weighted MRI scans, thus causing them to appear larger than their actual sizes and perhaps visible even when their size is below the nominal resolution limit of the imaging experiment. To evaluate this hypothesis, formalin‐fixed superior temporal gyrus samples obtained from two Alzheimer's disease and two control subjects were imaged using magnetic resonance microscopy at 11.7 T. Three dimensional T2*‐weighted gradient echo images were recorded with an isotropic resolution of 23.4 µm. The imaging protocol was especially sensitive to susceptibility effects. Samples were then stained for amyloid and/or iron deposits. Hypo‐ and hyper‐intense structures were clearly visible in MR images from all samples. Hyper‐intense structures reflected fixative penetration within the vascular system. Almost all the hypo‐intense structures were blood vessels. Their hypo‐intense profile was probably caused by iron deposits associated with the cell aggregates that they contained. Only one hypo‐intense spot could be matched with a plaque and this was one of the largest plaques in our samples. The remainder of the several hundred plaques were not visible in MR images. In histological slices the senile plaques were often larger than small blood vessels that were visible in the MR images. This suggests that susceptibility effects are not associated with senile plaques and do not provide a mechanism to differentiate them from surrounding tissue. Copyright © 2002 John Wiley & Sons, Ltd.
Electronic voting in a large‐scale distributed system
Authors: Dini Gianluca
Published: August 2002

In this paper, we propose a practical and secure electronic voting scheme suitable for large‐scale distributed systems such as the Internet. As in most of the voting systems in the literature, the proposed voting scheme allows only eligible voters to vote once, protects the voters' privacy, and ensures the accuracy of the tally. In addition, the proposed scheme satisfies further important criteria, namely, it tolerates abstention and does not require voters to control whether their votes have been correctly processed. If a subset of voters does not vote, the elections cannot be disrupted. Furthermore, anyone, including an external observer, can easily be convinced that the election is fair, that is, that the published final tally is fairly computed from the ballots that were correctly cast. It follows that the proposed voting scheme strengthens the security properties of the electronic voting procedure, simplifies the interaction of voters with the electronic voting system, and contributes to increased voter confidence in the degree of security of the electronic voting procedure. © 2001 John Wiley & Sons, Inc.
A catalog of Hanan grid problems
Authors: Zachariasen Martin
Published: August 2002

We present a general rectilinear Steiner tree problem in the plane and prove that it is solvable on the Hanan grid of the input points. This result is then used to show that several variants of the ordinary rectilinear Steiner tree problem are solvable on the Hanan grid, including—but not limited to—Steiner trees for rectilinear (or isothetic) polygons, obstacle‐avoiding Steiner trees, group Steiner trees, and prize‐collecting Steiner trees. Also, the weighted region Steiner tree problem is shown to be solvable on the Hanan grid; this problem has natural applications in VLSI design routing. Finally, we give similar results for other rectilinear problems. © 2001 John Wiley & Sons, Inc.
Long‐term culture of mouse cortical neurons as a model for neuronal development, aging, and death
Authors: Lesuisse Christian , Martin Lee J.
Published: August 2002

A long‐term cell culture system was used to study maturation, aging, and death of cortical neurons. Mouse cortical neurons were maintained in culture in serum‐free medium (Neurobasal supplemented with B27) for 60 days in vitro (DIV). The levels of several proteins were evaluated by immunoblotting to demonstrate that these neurons matured by developing dendrites and synapses and remained continuously healthy for 60 DIV. During their maturation, cortical neurons showed increased or stable protein expression of glycolytic enzyme, synaptophysin, synapsin IIa, α and β synucleins, and glutamate receptors. Synaptogenesis was prominent during the first 15 days and then synaptic markers remained stable through DIV60. Very early during dendritic development at DIV3, β‐synuclein (but not α‐synuclein) was localized at the base of dendritic growth cones identified by MAP2 and α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole (AMPA) receptor GluR1. In mature neurons, α and β synucleins colocalized in presynaptic axon terminals. Expression of N‐methyl‐D‐aspartate (NMDA) and AMPA receptors preceded the formation of synapses. Glutamate receptors continued to be expressed strongly through DIV60. Cortical neurons aging in vitro displayed a complex profile of protein damage as identified by protein nitration. During cortical neuron aging, some proteins showed increased nitration, while other proteins showed decreased nitration. After exposure to DNA damaging agent, young (DIV5) and old (DIV60) cortical neurons activated apoptosis mechanisms, including caspase‐3 cleavage and poly(ADP)‐ribose polymerase inactivation. We show that cultured mouse cortical neurons can be maintained for long term. Cortical neurons display compartmental changes in the localization of synucleins during maturation in vitro. These neurons sustain protein nitration during aging and exhibit age‐related variations in the biochemistry of neuronal apoptosis. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 9–23, 2002
Dominant‐negative NSF2 disrupts the structure and function of drosophila neuromuscular synapses
Authors: Stewart Bryan A. , Mohtashami Mahmood , Rivlin Patricia , Deitcher David L. , Trimble William S. , Boulianne Gabrielle L.
Published: August 2002

N‐ethylmaleimide sensitive fusion protein (NSF) is an ATPase necessary for vesicle trafficking, including exocytosis. Current models hold that NSF is required in a step that readies vesicles for fusion by disassembling postfusion SNARE protein complexes allowing them to participate in further rounds of vesicle cycling. Whereas most organisms have only one NSF isoform, Drosophila has two. dNSF1 is the predominant functional isoform in the adult nervous system. Conditional mutations in the dNSF1 gene, comatose, are paralytic and lead to disruption of synaptic transmission and the rapid accumulation of SNARE complexes in adult flies. This isoform is not required for synaptic transmission in larvae. In contrast, dNSF2 is important at earlier developmental stages, and its broad expression indicates its importance in neural and non‐neural tissues alike. To study dNSF2, and to circumvent the lethality of dNSF2 null mutants, we have constructed transgenic flies carrying a dominant negative form of dNSF2. When this construct was expressed in neurons we observed suppression of synaptic transmission, activity‐dependent fatigue of transmitter release, and a reduction in the number of releasable vesicles. However, we unexpectedly found that there was no accumulation of SNARE complexes accompanying these physiological phenotypes. Intriguingly, we also found that expression of mutant dNSF2 induced pronounced overgrowth of the neuromuscular junction and some misrouting of axons. These results support the idea that dNSF2 has multiple roles in cellular function and adds that not all of its functions require disassembly of the SNARE complex. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 261–271, 2002
Evaluating products of matrix pencils and collapsing matrix products
Authors: Benner Peter , Byers Ralph
Published: August 2002

This paper describes three numerical methods to collapse a formal product ofppairs of matrices$$P=\mathop{\prod}\limits_{k=0}^{p-1} E_{k}^{-1}A_{k}$$down to the product of a single pairÊ−1Â. In the setting of linear relations, the product formally extends to the case in which some of theEk's are singular and it is impossible to explicitly form P as a single matrix. The methods differ in flop count, work space, and inherent parallelism. They have in common that they are immune to overflows and use no matrix inversions. A rounding error analysis shows that the special case of collapsing two pairs is numerically backward stable. Copyright © 2001 John Wiley & Sons, Ltd.
Modelling of elastic continua using a grillage of structural elements based on discrete element concepts
Authors: Griffiths D. V. , Mustoe G. G. W.
Published: August 2002

A framework is described for modelling an elastic continuum using a grillage of beam‐like structural elements derived from discrete element concepts. The beam element properties are derived in detail and implemented in a structural analysis code for validation against classical two‐dimensional plane elasticity solutions. The framework offers the possibility of modelling the onset and propagation of fracture in materials that are initially continuous, without the need for specialized elements or remeshing in the context of traditional finite elements. Copyright © 2001 John Wiley & Sons, Ltd.
The emotional reality of teams
Authors: Goleman Daniel , Boyatzis Richard , McKee Annie
Published: August 2002

The capabilities that the authors have defined as components of Emotional
Intelligence—self‐awareness, self‐management, social awareness, and relationship
management—apply to teams as well as individuals. And so, to optimize a team's effectiveness, its
members—and especially its leader(s)—must “tune in” to its emotional state and
needs. © 2002 by Daniel Goleman
Mothers' evaluation of their caregiving for premature and full‐term infants through the first year: Contributing factors
Authors: Pridham Karen , Lin Chin‐Yu , Brown Roger
Published: August 2002

We explored change in mothers' evaluations of their caregiving through the first postterm year for full‐term infants and for prematurely born, very low birth‐weight infants with a history of lung disease, and we examined the contribution to this evaluation of infant, family, and mother conditions. Fifty‐four mothers of premature infants and 49 mothers of full‐term infants evaluated their caregiving relationship, performance, and satisfaction at 1, 4, 8, and 12 months infant postterm age. In addition, at the same intervals—1, 4, 8, and 12 months—mothers rated their symptoms of depression, infant responsiveness, and satisfaction with help from husband or partner. Positive and negative feeding behaviors of mother and of infant were rated from videotapes. Regression analysis, which included all rated variables, infant birth maturity/lung health status, and number of children in the mother's care, showed that the 1‐month assessment differed significantly from the assessments at 4, 8, and 12 months. All conditions, except for infant birth maturity/lung health status and mother's positive feeding behavior, were significantly associated with caregiving evaluation. Findings support inclusion of infant, family, and mother conditions in a caregiving evaluation model. Infant responsiveness may be particularly salient to a mother's caregiving evaluation. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24: 157–169, 2001
Enduring love: A grounded formal theory of women's experience of domestic violence
Authors: Kearney Margaret H.
Published: August 2002

Using a grounded formal theory approach, 13 qualitative research reports were analyzed with the goal of synthesizing a middle‐range theory of women's responses to violent relationships. The combined sample numbered 282 ethnically and geographically diverse women ages 16–67. Within cultural contexts that normalized relationship violence while promoting idealized romance, these women dealt with the incongruity of violence in their relationships as a basic process of enduring love. In response to shifting definitions of their relationship situations, many women moved through four phases, which began with discounting early violence for the sake of their romantic commitment (“This is what I wanted”), progressed to immobilization and demoralization in the face of increasingly unpredictable violence that was endured by the careful monitoring of partner behavior and the stifling of self (“The more I do, the worse I am”), shifted to a perspective that redefined the situation as unacceptable (“I had enough”), and finally moved out of the relationship and toward a new life (“I was finding me”). Variations in the manifestation and duration of these phases were found to be linked to personal, sociopolitical, and cultural contexts. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:270–282, 2001
Interventions to reduce the burden of caregiving for an adult with dementia: A meta‐analysis§
Authors: Acton Gayle J. , Kang Jeonghee
Published: August 2002

Because of conflicting results, in order to clarify the state of the science it was necessary to do a systematic analysis of the literature on research testing the effect of interventions on the burden of persons caring for family members with dementia. The purpose of this study was to evaluate, using meta‐analytic techniques, those intervention strategies (support group, education, psychoeducation, counseling, respite care, and multicomponent) designed to help caregivers cope with the burden of caregiving. Using meta‐analytic methods developed by Glass, McGraw, and Smith (1981) and Hedges and Olkin (1985), 24 published research reports testing 27 treatments for caregivers of adults with dementia were synthesized. Overall, the analysis showed that collectively the interventions had no effect on caregiver burden. Only the category of multicomponent interventions significantly reduced caregiver burden. Burden may be too global an outcome to be affected consistently by intervention. Better and more precise measures are needed to evaluate the effects of caregiver interventions properly. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:349–360, 2001
Destruction of microstructure in archaeological bone: a case study from Portugal
Authors: Jackes Mary , Sherburne Richard , Lubell David , Barker Christina , Wayman Michael
Published: August 2002

Sampling of archaeological human bone may not be justified, contrary to former high expectations regarding adult age assessment based on histomorphometry. The alterations in buried bone as a result of bacterial action are readily visible in the scanning electron microscope (SEM). An understanding of the chemical and structural changes to cortical bone requires work at the level of a few microns. This paper reports on problems encountered during analyses of samples of human bone from Mesolithic (ca. 8000 calbp) shell midden sites at Muge in central Portugal, and the methods used to try and overcome these problems. We believe we have shown that these Mesolithic bones are partly comprised of bacterially reprecipitated mineral, which has had collagen removed, with consequent obliteration of bone microstructure. We conclude that microbial destruction of the structure of archaeological bone can be a serious impediment to analysis of the characteristics of the population represented by those skeletal remains. Copyright © 2001 John Wiley & Sons, Ltd.
The distribution of skeletal lesions in treponemal disease: is the lymphatic system responsible?
Authors: Buckley Hallie R. , Dias George J.
Published: August 2002

The differential diagnosis of bone lesions in treponemal disease is well established in palaeopathology. However, the actual mechanism responsible for the characteristic distribution of bone involvement is not as clear. Two mechanisms are proposed in the literature. Firstly, that bone lesions are the result of direct extension from the skin rash of the secondary stage of disease. Secondly, that bones situated closer to the skin are more vulnerable to local trauma and therefore more likely to elicit a subperiosteal bone response. We propose an alternative explanation for the characteristic distribution of bone lesions in treponemal disease. This explanation is based on the close association between the lymphatic and skeletal systems and the pathogenesis of treponemal disease. This paper argues that the position of the lymphatic nodes and vessels, with little soft tissue intervention between bone tissue, mirrors the characteristic pattern of skeletal involvement in treponemal disease. Copyright © 2002 John Wiley & Sons, Ltd.