bluuebunny/crossref_metadata_2025 huggingface dataset:
Bulk magnetic susceptibility effects on the assessment of intra‐ and extramyocellular lipids in vivo
Authors: Szczepaniak Lidia S. , Dobbins Robert L. , Stein Daniel T. , McGarry J. Denis
Published: August 2002

Localized proton spectroscopy provides a novel method for noninvasive measurement of lipid content in skeletal muscle. It has been suggested that the chemical shift difference between lipid signals from distinct compartments in skeletal muscle might be caused by bulk magnetic susceptibility (BMS) differences from lipids stored in intra‐ (IMCL) and extramyocellular (EMCL) compartments. Direct evidence is provided to confirm the theoretical prediction that compartment symmetry is responsible for discrimination between resonances of IMCL and EMCL. Phantoms imitating lipids in skeletal muscle were constructed using soybean oil to represent EMCL, and Intralipid™, an intravenous fat emulsion of fine droplets, to represent IMCL. It was found that the chemical shift of Intralipid™ is independent of the BMS effects, while the resonance of soybean oil shifts in a predictable manner determined by the geometry of the compartment. Magn Reson Med 47:607–610, 2002. © 2002 Wiley‐Liss, Inc.
White matter mapping using diffusion tensor MRI
Authors: Tench C.R. , Morgan P.S. , Wilson M. , Blumhardt L.D.
Published: August 2002

Diffusion tensor MRI is used to define trajectories that reflect the long‐range order of in vivo white matter (WM) fiber tracts. Fiber tracking is particularly prone to cumulative error from noise and partial volume along the length of the trajectory paths, but the overall shape of each path is anatomically meaningful. By considering only the long‐range similarity of path shapes, a method of constructing 3D maps of specific WM structures has been developed. A trajectory is first computed from an operator‐selected seed voxel, located within the anatomical structure of interest (SOI). Voxels from the same structure are then automatically identified based on the similarity of trajectory path shapes, assessed using Pearson's correlation coefficient. The corpus callosum and pyramidal tracts in 14 patients with multiple sclerosis, and in 10 healthy controls were mapped by this method, and the apparent diffusion coefficient (ADC) was measured. The ADC was significantly higher in patients than in controls, and higher in the corpus callosum than in the pyramidal tracts for both groups. Using this method the different functional structures in the WM may be identified and mapped. Within these maps, MRI parameters can be measured for subsequent comparison with relevant clinical data. Magn Reson Med 47:967–972, 2002. © 2002 Wiley‐Liss, Inc.
In vivo 1H NMR spectroscopy of the human brain at 7 T
Authors: Tkáč Ivan , Andersen Peter , Adriany Gregor , Merkle Hellmut , Uǧurbil Kâmil , Gruetter Rolf
Published: August 2002

In vivo 1H NMR spectra from the human brain were measured at 7 T. Ultrashort echo‐time STEAM was used to minimize J‐modulation and signal attenuation caused by the shorter T2 of metabolites. Precise adjustment of higher‐order shims, which was achieved with FASTMAP, was crucial to benefit from this high magnetic field. Sensitivity improvements were evident from single‐shot spectra and from the direct detection of glucose at 5.23 ppm in 8‐ml volumes. The linewidth of the creatine methyl resonance was at best 9 Hz. In spite of the increased linewidth of singlet resonances at 7 T, the ability to resolve overlapping multiplets of J‐coupled spin systems, such as glutamine and glutamate, was substantially increased. Characteristic spectral patterns of metabolites, e.g., myo‐inositol and taurine, were discernible in the in vivo spectra, which facilitated an unambiguous signal assignment. Magn Reson Med 46:451–456, 2001. © 2001 Wiley‐Liss, Inc.
T2 relaxation reveals spatial collagen architecture in articular cartilage: A comparative quantitative MRI and polarized light microscopic study
Authors: Nieminen Miika T. , Rieppo Jarno , Töyräs Juha , Hakumäki Juhana M. , Silvennoinen Johanna , Hyttinen Mika M. , Helminen Heikki J. , Jurvelin Jukka S.
Published: August 2002

It has been suggested that orientational changes in the collagen network of articular cartilage account for the depthwise T2 anisotropy of MRI through the magic angle effect. To investigate the relationship between laminar T2 appearance and collagen organization (anisotropy), bovine osteochondral plugs (N = 9) were T2 mapped at 9.4T with cartilage surface normal to the static magnetic field. Collagen fibril arrangement of the same samples was studied with polarized light microscopy, a quantitative technique for probing collagen organization by analyzing its ability to rotate plane polarized light, i.e., birefringence (BF). Depthwise variation of safranin O‐stained proteoglycans was monitored with digital densitometry. The spatially varying cartilage T2 followed the architectural arrangement of the collagen fibril network: a linear positive correlation between T2 and the reciprocal of BF was established in each sample, with r = 0.91 ±
0.02 (mean ± SEM, N = 9). The current results reveal the close connection between the laminar T2 structure and the collagen architecture in histologic zones. Magn Reson Med 46:487–493, 2001. © 2001 Wiley‐Liss, Inc.
Muscle metabolic economy is inversely related to exercise intensity and type II myofiber distribution
Authors: Hunter Gary R. , Newcomer Brad R. , Larson‐Meyer D. Enette , Bamman Marcas M. , Weinsier Roland L.
Published: August 2002

It is not known what causes the well‐established inverse relationship between whole‐body exercise economy and exercise intensity. The purpose of this study was to: (1) evaluate muscle exercise economy at 45%, 70%, and maximum isometric strength using 31P magnetic resonance spectroscopy (31P‐MRS); and (2) determine the relationship between percent type II muscle fiber cross‐section, whole‐body exercise economy, and muscle exercise economy. Subjects included 32 premenopausal women. Muscle exercise economy was significantly different across the three exercise intensities (28.1 ± 10.4, 24.8 ± 8.2, and 20.2 ± 7.5 N/cm2 · mmol/L adenosine triphosphate [ATP] for the 45%, 70%, and maximum intensities, respectively). Percent type II muscle area was significantly related to whole‐body metabolic economy during activities of daily living (r = −0.68) and 31P‐MRS muscle metabolic economy during isometric plantar flexion (r = −0.53). These data suggest that skeletal muscle becomes less economical as force production increases, and that these decreases in metabolic economy may be related to increased dependence on inefficient type II muscle. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 654–661, 2001
Acquired neuromyotonia and peripheral neuropathy in a patient with Hodgkin's disease
Authors: Lahrmann Heinz , Albrecht Gerhard , Drlicek Markus , Oberndorfer Stefan , Urbanits Sabine , Wanschitz Julia , Zifko Udo A. , Grisold Wolfgang
Published: August 2002

Acquired neuromyotonia is characterized by hyperexcitability of motor nerves resulting in continuous muscle fiber activity. It occurs most often as a paraneoplastic syndrome in patients with cancers of the immune system. Antibodies against voltage‐gated potassium channels (VGKCs) have been detected in some patients. Peripheral neuropathy is sometimes present. We report on a patient with Hodgkin's lymphoma in complete remission who developed paresthesias followed by neuromyotonia with bulbar involvement. Peripheral sensorimotor neuropathy was diagnosed electrophysiologically and evidence of axonal degeneration and demyelination was detected by sural nerve biopsy. The patient's complaints, including dysarthria, improved after carbamazepine treatment. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 834–838, 2001
Contralateral reinnervation of midline muscles in facial paralysis
Authors: Gilhuis H. Jacobus , Beurskens Carien H.G. , Marres Henri A.M. , de Vries Joost , Hartman Ed H.M. , Zwarts Machiel J.
Published: August 2002

We report on a patient with recovery of activity of the left orbicularis oris and nasalis muscles 3 months after a complete left facial palsy. Stimulation of the affected facial nerve evoked no responses, whereas contralateral facial nerve stimulation showed polyphasic responses with very long latencies in the nasalis and orbicularis oris muscles. Needle electromyography (EMG) revealed abnormal spontaneous activity in the left orbicularis oris muscle. The motor unit action potentials on the left side of the face could be recruited only during marked contraction of the corresponding muscles on the right and were of low voltage and polyphasic (“nascent potentials”). Contralateral reinnervation is probably due to sprouting of terminal branches crossing the midline of the face and innervating bundles of muscle fibers on the affected side. This phenomenon seems unfamiliar to most clinicians. Whether the activity is due to conduction along nerve fibers or muscle fibers crossing the midline is discussed. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24:1703–1705
Microstructural deformation mechanisms of unsaturated granular soils
Authors: Gili J. A. , Alonso E. E.
Published: August 2002

A discrete model for unsaturated granular soils has been developed. Three discrete entities have been defined: particles, water menisci and pores. Local interaction forces and water transfer mechanisms have been integrated into a model through the appropriate equilibrium and balance equations. The results of several numerical tests using this model have been described and discussed. Simulations include wetting and drying under load tests, the application of suction cycles and the effect of a deviatoric stress ratio on wetting‐induced collapse. The model reacts just as true granular soil samples behave in laboratory tests. The model provides a new insight into the internal mechanisms leading to large‐scale features of behaviour such as wetting‐induced collapse or the increase in soil strength provided by suction. The paper also stresses that matric suction changes acting on a granular structure are capable of explaining most of the macroscopic features of stress–strain behaviour. Copyright © 2002 John Wiley & Sons, Ltd.
A linear‐size zero—one programming model for the minimum spanning tree problem in planar graphs
Authors: Williams Justin C.
Published: August 2002

A new linear zero‐one programming model is presented for the problem of finding minimum spanning trees (MSTs) in undirected planar graphs. Existing MST solution algorithms, which are applicable to both planar and nonplanar graphs, have strong computational advantages over existing MST integer‐linear programming (LP) models. The latter tend not to be amenable to LP solution methods except for relatively small problems, but may, nevertheless, be desirable for reasons of convenience, exibility, and adaptability to related and difficult problems such as the network Steiner tree problem. The purpose of this paper was to present a zero—one model whose size and solvability more closely resemble the properties of existing algorithms than do other proposed integer‐LP models. This new model exploits the special primal‐dual structure that exists for planar graphs. The model's constraint matrix is both unimodular and linear in size relative to graph size. Hence, LP solution methods become practical for solving large planar graph MST problems exactly. A bi‐objective generalization of the model is presented and the model's LP dual is briefly discussed. © 2001 John Wiley & Sons, Inc.
Injury‐induced spinal motor neuron apoptosis is preceded by DNA single‐strand breaks and is p53‐ and Bax‐dependent
Authors: Martin Lee J. , Liu Zhiping
Published: August 2002

The mechanisms of injury‐induced apoptosis of neurons within the spinal cord are not understood. We used a model of peripheral nerve‐spinal cord injury in the rat and mouse to induce motor neuron degeneration. In this animal model, unilateral avulsion of the sciatic nerve causes apoptosis of motor neurons. We tested the hypothesis that p53 and Bax regulate this neuronal apoptosis, and that DNA damage is an early upstream signal. Adult mice and rats received unilateral avulsions causing lumbar motor neurons to achieve endstage apoptosis at 7–14 days postlesion. This motor neuron apoptosis is blocked in bax−/− and p53−/− mice. Single‐cell gel electrophoresis (comet assay), immunocytochemistry, and quantitative immunogold electron microscopy were used to measure molecular changes in motor neurons during the progression of apoptosis. Injured motor neurons accumulate single‐strand breaks in DNA by 5 days. p53 accumulates in nuclei of motor neurons destined to undergo apoptosis. p53 is functionally activated by 4–5 days postlesion, as revealed by immunodetection of phosphorylated p53. Preapoptotically, Bax translocates to mitochondria, cytochrome c accumulates in the cytoplasm, and caspase‐3 is activated. These results demonstrate that motor neuron apoptosis in the adult spinal cord is controlled by upstream mechanisms involving DNA damage and activation of p53 and downstream mechanisms involving upregulated Bax and cytochrome c and their translocation, accumulation of mitochondria, and activation of caspase‐3. We conclude that adult motor neuron death after nerve avulsion is DNA damage‐induced, p53‐ and Bax‐dependent apoptosis. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 181–197, 2002; DOI 10.1002/neu.10026
Calcium transients in subcompartments of the leech Retzius neuron as induced by single action potentials
Authors: Beck Andreas , Lohr Christian , Deitmer Joachim W.
Published: August 2002

Regional Ca2+ influx into neurons plays an essential role for fast signal processing, yet it is little understood. We have investigated intracellular Ca2+ transients induced by a single action potential (AP) in Retzius neurons in situ of isolated ganglia of the leech Hirudo medicinalis using confocal laser scanning microscopy in the cell body, in different axonal branches, and in dendrites. In the cell body, a single AP induced a Ca2+ transient in submembrane regions, while in central regions no fluorescence change was detected. Burst activity evoked a much larger Ca2+ influx, which elicited Ca2+ signals in central somatic regions, including the cell nucleus. A single AP induced a Ca2+ transient in distal branches of the axon and in dendrites that was significantly larger than in the proximal axon and in the cell body (p < .05), and the recovery of the Ca2+ transient was significantly faster in axonal branches than in dendrites (p < .01). The AP‐induced Ca2+ transient was inhibited by Co2+ (2 mM). The P/Q‐type Ca2+ channel blocker ω‐agatoxin TK (500 nM) and the L‐type Ca2+ channel blocker nifedipine (20 μM) had no effect on the Ca2+ transient, whereas the L‐type Ca2+ channel blocker methoxyverapamil (D600, 0.5–1 mM) irreversibly reduced the Ca2+ transient by 37% in axons and by 42% in dendrites. Depletion of intracellular Ca2+ stores following inhibition of endoplasmic Ca2+‐ATPases by cyclopiazonic acid (10 μM) decreased the AP‐induced Ca2+ transient in the dendrites by 21% (p < .01), but not in axons, and increased the Ca2+ recovery time constant (τ) in the axonal branches by 129% (p < .01), but not in dendrites. The results indicate that an AP evokes a voltage‐gated Ca2+ influx into all subcompartments of the Retzius neuron, where it produces a Ca2+ signal of different size and/or kinetics. This may contribute to the modulation of electrical excitation and propagation of APs, and to different modes of synaptic and nonsynaptic processes. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 1–18, 2001
Error norm estimation and stopping criteria in preconditioned conjugate gradient iterations
Authors: Axelsson Owe , Kaporin Igor
Published: August 2002

Some techniques suitable for the control of the solution error in the preconditioned conjugate gradient method are considered and compared. The estimation can be performed both in the course of the iterations and after their termination.The importance of such techniques follows from the non‐existence of some reasonable a priori error estimate for very ill‐conditioned linear systems when sufficient information about the right‐hand side vector is lacking. Hence, some a posteriori estimates are required, which make it possible to verify the quality of the solution obtained for a prescribed right‐hand side. The performance of the considered error control procedures is demonstrated using real‐world large‐scale linear systems arising in computational mechanics. Copyright © 2001 John Wiley & Sons, Ltd.
On elimination of shear locking in the element‐free Galerkin method
Authors: Kanok‐Nukulchai W. , Barry W. , Saran‐Yasoontorn K. , Bouillard P. H.
Published: August 2002

In this study, a method for completely eliminating the presence of transverse shear locking in the application of the element‐free Galerkin method (EFGM) to shear‐deformable beams and plates is presented. The matching approximation fields concept of Donning and Liu has shown that shear locking effects may be prevented if the approximate rotation fields are constructed with the innate ability to match the approximate slope (first derivative of displacement) fields and is adopted. Implementation of the matching fields concept requires the computation of the second derivative of the shape functions. Thus, the shape functions for displacement fields, and therefore the moving least‐squares (MLS) weight function, must be at least C1 continuous. Additionally, the MLS weight functions must be chosen such that successive derivatives of the MLS shape function have the ability to exactly reproduce the functions from which they were derived. To satisfy these requirements, the quartic spline weight function possessing C2 continuity is used in this study. To our knowledge, this work is the first attempt to address the root cause of shear locking phenomenon within the framework of the element‐free Galerkin method. Several numerical examples confirm that bending analyses of thick and thin beams and plates, based on the matching approximation fields concept, do not exhibit shear locking and provide a high degree of accuracy for both displacement and stress fields. Copyright © 2001 John Wiley & Sons, Ltd.
An assumed strain triangular curved solid shell element formulation for analysis of plates and shells undergoing finite rotations
Authors: Hong Won I. , Kim Jong H. , Kim Yong H. , Lee Sung W.
Published: August 2002

A formulation for 36‐DOF assumed strain triangular solid shell element is developed for efficient analysis of plates and shells undergoing finite rotations. Higher order deformation modes described by the bubble function displacements are added to the assumed displacement field. The assumed strain field is carefully selected to alleviate locking effect. The resulting element shows little effect of membrane locking as well as shear locking, hence, it allows modelling of curved shell structures with curved elements. The kinematics of the present formulation is purely vectorial with only three translational degrees of freedom per node. Accordingly, the present element is free of small angle assumptions, and thus it allows large load increments in the geometrically non‐linear analysis. Various numerical examples demonstrate the validity and effectiveness of the present formulation. Copyright © 2001 John Wiley & Sons, Ltd.
Remarks on tension instability of Eulerian and Lagrangian corrected smooth particle hydrodynamics (CSPH) methods
Authors: Bonet Javier , Kulasegaram Sivakumar
Published: August 2002

The paper discusses the problem of tension instability of particle‐based methods such as smooth particle hydrodynamics (SPH) or corrected SPH (CSPH). It is shown that tension instability is a property of a continuum where the stress tensor is isotropic and the value of the pressure is a function of the density or volume ratio. The paper will show that, for this material model, the non‐linear continuum equations fail to satisfy the stability condition in the presence of tension. Consequently, any discretization of this continuum will result in negative eigenvalues in the tangent stiffness matrix that will lead to instabilities in the time integration process. An important exception is the 1‐D case where the continuum becomes stable but SPH or CSPH can still exhibit negative eigenvalues. The paper will show that these negative eigenvalues can be eliminated if a Lagrangian formulation is used whereby all derivatives are referred to a fixed reference configuration. The resulting formulation maintains the momentum preservation properties of its Eulerian equivalent. Finally a simple 1‐D wave propagation example will be used to demonstrate that a stable solution can be obtained using Lagrangian CSPH without the need for any artificial viscosity. Copyright © 2001 John Wiley & Sons, Ltd.
Measuring stigma in people with HIV: Psychometric assessment of the HIV stigma scale¶
Authors: Berger Barbara E. , Ferrans Carol Estwing , Lashley Felissa R.
Published: August 2002

An instrument to measure the stigma perceived by people with HIV was developed based on the literature on stigma and psychosocial aspects of having HIV. Items surviving two rounds of content review were assembled in a booklet and distributed through HIV‐related organizations across the United States. Psychometric analysis was performed on 318 questionnaires returned by people with HIV (19% women, 21% African American, 8% Hispanic). Four factors emerged from exploratory factor analysis: personalized stigma, disclosure concerns, negative self‐image, and concern with public attitudes toward people with HIV. Extraction of one higher‐order factor provided evidence of a single overall construct. Construct validity also was supported by relationships with related constructs: self‐esteem, depression, social support, and social conflict. Coefficient alphas between .90 and .93 for the subscales and .96 for the 40‐item instrument provided evidence of internal consistency reliability. The HIV Stigma Scale was reliable and valid with a large, diverse sample of people with HIV. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:518–529, 2001
A conceptual framework for understanding the process of family caregiving to frail elders in Taiwan*
Authors: Shyu Yea‐Ing Lotus
Published: August 2002

This descriptive, correlational study of family caregivers (N=125) tested a conceptual framework for family caregiving to frail elders in Taiwan, using the concept of “finding a balance point” derived from a previous qualitative study. It was hypothesized that caregivers who were better able to find a balance point among competing needs would provide better‐quality care to frail elders, which would lead to more positive caregiver and family outcomes. After controlling for the influence of caregiving characteristics and caregiving factors, finding a balance point significantly explained 7% of the variance in overall caregiving consequences. The findings of this study add a new perspective to the caregiving process in Taiwan. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:111–121, 2002
Rethinking cultural safety while waiting to do fieldwork: Methodological implications for nursing research*
Authors: Kirkham Sheryl Reimer , Smye Vicki , Tang Sannie , Anderson Joan , Blue Connie , Browne Annette , Coles Ruth , Dyck Isabel , Henderson Angela , Lynam M. Judith , Perry JoAnn , Semeniuk Pat , Shapera Leah
Published: August 2002

The concept of culture has been widely applied as an explanatory concept within health care, often within a framework representing culture as a fixed, reified entity, with cultural groups existing in a binary sense vis‐´‐vis mainstream culture. However, if our scholarship is to generate knowledge that addresses longstanding patterns of inclusion and exclusion along lines such as race, ethnicity, class, and gender, interpretive frames are needed that account for culture as embedded in fields of power relations; as mediated by social forces such as economics, politics, and historical patterns of oppression and colonization; and as being constantly renegotiated. In this article we trace a series of theoretical explorations, centered on the concept of cultural safety, with corresponding methodological implications, engaged in during preparation for an intensive period of fieldwork to study the hospitalization and help‐seeking experiences of diverse ethnocultural populations. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:222–232, 2002
Levels and applications of qualitative research evidence
Authors: Kearney Margaret H.
Published: August 2002

Evaluation of qualitative findings for application to nursing practice can go beyond the rigor with which the evidence was developed to the characteristics of the findings themselves. Five categories of qualitative findings are described that vary in their levels of complexity and discovery: those restricted by a priori frameworks, descriptive categories, shared pathway or meaning, depiction of experiential variation, and dense explanatory description. Four modes of clinical application of qualitative evidence are proposed—insight or empathy, assessment of status or progress, anticipatory guidance, and coaching—that vary in their degree of visibility and patient involvement. The greater the complexity and discovery within qualitative findings, the stronger may be the potential for clinical application. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24: 145–153, 2001
Traditional Rotuman fishing in temporal and regional context
Authors: Allen Melinda S. , Ladefoged Thegn N. , Wall Jonathan J.
Published: August 2002

Few archaeological sites in the central western Pacific (i.e., Fiji–Samoa–Tonga region) have provided large and temporally well‐controlled archaeofaunal assemblages. Therefore, three sizable Rotuman assemblages, dating to the ca. 7th–11th century ad, provided an opportunity to improve our understanding of the region's traditional fishing practices. The assemblages are analysed in terms of taxonomic composition, abundances, and ecological associations of the taxa. Indications are that the foraging range and intensity of Rotuman fishing may have declined through time, although the results from this single site are interpreted with caution. Comparison with other Pacific assemblages suggests that this may be a common trajectory, one which is to varying degrees intertwined with agricultural intensification, the growth of animal husbandry systems, increased competition, and possibly resource depression. Copyright © 2001 John Wiley & Sons, Ltd.
Reconstructing dietary and environmental history from enamel isotopic analysis: time resolution of intra‐tooth sequential sampling
Authors: Balasse Marie
Published: August 2002

The carbon and oxygen isotopic composition of the mineral phase of tooth enamel is linked to diet and environment. Enamel is not remodelled once formed. Several studies of intra‐tooth isotopic variability in hypsodont mammal teeth have involved sequential sampling of enamel in order to detect changes in diet and environment during tooth formation. The possibility of exploring individual history opens the door to many applications, particularly in palaeoenvironment and herd management reconstruction. However, previous histological investigations have shown that enamel mineralization is a progressive and discontinuous process. The goal of the present study is to determine if this pattern significantly influences the time resolution of an intra‐tooth sequential sampling. Isotopic analyses (δ13C) were performed on tooth enamel from steers (Bos taurus) that had changed from a C3 plant‐based diet to a C4 plant‐based diet with very different carbon isotopic compositions. The change of diet was reflected in the mineral phase of enamel. The pattern of intra‐tooth isotopic variation suggests that completion of enamel mineralization required six to seven months. Such a lag in enamel mineralization will decrease the time resolution of enamel sequential sampling. The effects of prolonged mineralization of enamel have to be considered when interpreting patterns of intra‐tooth isotopic variations. Copyright © 2002 John Wiley & Sons, Ltd.
Telomerase and cancer: time to move from a promising target to a clinical reality
Authors: Nicol Keith W. , Jeffry Evans T. R. , Glasspool Rosalind M.
Published: August 2002

The past 25 years have seen unparalleled advances in our understanding of the molecular basis of cancer. As a result, novel molecular targets have been identified that provide great potential for the development of new cancer diagnostics and therapies. Four key features of cancer cells distinguish them from their normal counterparts: loss of cell‐cycle regulation, loss of control over invasion and metastasis, failure of apoptotic mechanisms, and bypass of senescence. This review examines our understanding of the bypass of senescence and the process of immortalization during carcinogenesis. In addition, the realistic opportunities for telomerase in cancer diagnostics and the challenges faced in clinical trial design for telomerase therapeutics are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
PAS‐positive loops and networks as a prognostic indicator in cutaneous malignant melanoma
Authors: Thies Anka , Mangold Ulrich , Moll Ingrid , Schumacher Udo
Published: August 2002

Recently, microvascular channels, as detected by PAS histochemistry, were positively correlated with poor prognosis in uveal malignant melanoma. Since uveal melanomas are not penetrated by lymphatic vessels, while cutaneous melanomas are, the question arises as to whether these loops and networks are also of prognostic relevance in cutaneous melanoma. Histochemically and immunohistochemically detected loops and networks in 100 cases of cutaneous malignant melanoma were correlated with the occurrence of metastasis in a 10‐year follow‐up study. To detect these patterns, the significance of various methods (PAS reaction with/without nuclear counterstain, anti‐laminin immunohistochemistry) was investigated. The presence of loops and networks was a highly significant prognostic marker (p<0.0001) for metastasis in cutaneous malignant melanoma. The presence of these patterns proved to have higher prognostic relevance for metastasis than Breslow's tumour thickness, especially for stage IB and stage IIA tumours (intermediate thickness/risk). PAS reaction without nuclear counterstain proved to be the best method to detect these patterns. Compared with the conventional staging of Breslow's tumour thickness, and especially so for stage IB and IIA melanomas, the determination of PAS‐positive loops and networks in cutaneous malignant melanoma provides additional prognostic information. Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal diagnosis for women aged 37 years and over: to have or not to have
Authors: Halliday Jane L. , Warren Rosemary , McDonald Geraldine , Liamputtong Rice Pranee , Bell Robin J. , Watson Lyndsey F.
Published: August 2002

Forty percent of pregnant women aged 37 years and over do not have prenatal diagnosis despite being eligible for a free test. The present study aimed to determine how often, and which, untested women were making a choice about this, how many declined an offer and why. A questionnaire was given to untested women, aged 37 years and over, at no less than 24 weeks gestation. A total of 375 (81.5%) women declined, 72 (16%) were not offered a test and 13 presented too late antenatally. There was a three‐fold increased likelihood (OR 3.10 95% CI 1.44, 6.65) of no offer for urban non‐English speaking background women, compared with the reference group (metropolitan, English speaking). Unpartnered women were also significantly less likely to receive an offer (OR 3.18, 95% CI 1.19, 8.46). Risk to the baby was the main reason for declining. When offered non‐invasive prenatal screening, most decliners of prenatal diagnosis accepted, even those who declined because they were opposed to abortion. We estimate that overall 33% of older pregnant women were being offered and declining amniocentesis and/or chorion villus sampling (CVS). Only 6% were not offered a test, but this small proportion is over‐represented by minority groups who must be given equal opportunity to make this choice. Copyright © 2001 John Wiley & Sons, Ltd.
Descriptive information about Down syndrome: a content analysis of serum screening leaflets
Authors: Bryant Louise D. , Murray Jenni , Green Josephine M. , Hewison Jenny , Sehmi Indera , Ellis Andy
Published: August 2002

It is recommended practice that prior to prenatal screening, women receive information about the condition(s) being tested for. The present study critically evaluated information about Down syndrome as contained in 80 leaflets provided to pregnant women in the UK prior to serum screening. First, a content analysis by information type was conducted to give an overall picture of the material provided. Second, the image of the condition as conveyed by the content was analysed and compared with a similar study of cystic fibrosis (CF) screening leaflets. The majority of information (89%) was of a medico‐clinical nature, with 11% addressing other issues associated with Down syndrome. The median number of sentences describing the condition was one, with 33% of the leaflets containing no descriptive information. Overall, a negative image of Down syndrome was conveyed by the leaflets, which contrasted with a more neutral image of CF in the comparison study. In order to facilitate informed choices, more attention should be paid to providing women with information about Down syndrome prior to serum screening. Such information needs to be more balanced in its construction, with thought given to the needs of the reader, and to the tone and the content of the message conveyed. Copyright © 2001 John Wiley & Sons, Ltd.
Molecular diagnosis of a novel heterozygous 268C→T (R90C) mutation in TGIF gene in a fetus with holoprosencephaly and premaxillary agenesis
Authors: Chen Chih‐Ping , Chern Schu‐Rern , Du Shin‐Hua , Wang Wayseen
Published: August 2002

We report the sonographic diagnosis and molecular analysis of holoprosencephaly (HPE) and premaxillary agenesis in a second‐trimester fetus with a 46,XY karyotype. Mutational sequence analyses for the entire coding region and exon–intron boundaries of SHH, ZIC2, SIX3 and TGIF genes identified a novel heterozygous missense TGIF mutation 268C→T (CGC→TGC change) that predicts an Arg90Cys substitution in the homeodomain region of TGIF. The proband's parents did not carry the mutation. The present case is an example of the heterogeneous entity of the HPE spectrum and demonstrates that adjunctive molecular analyses of distinct human genes for HPE can reassure genetic counselling by elucidating the genetic pathogenesis, especially in cytogenetically normal fetuses affected with HPE. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of cri du chat (5p‐) syndrome in association with isolated moderate bilateral ventriculomegaly
Authors: Stefanou E.‐G. G. , Hanna G. , Foakes A. , Crocker M. , Fitchett M.
Published: August 2002

A case of prenatally detected cri du chat syndrome (5p‐) is reported. Amniocentesis was performed following an abnormal ultrasound finding of isolated moderate bilateral ventriculomegaly. The karyotype showed a terminal deletion of the short arm of chromosome 5 including the critical region 5p15 for cri du chat syndrome. This was confirmed by fluorescence in situ hybridisation (FISH). Isolated mild ventriculomegaly may be a non‐specific marker for cri du chat syndrome. Copyright © 2002 John Wiley & Sons, Ltd.
Pattern recognition in health insurance claims databases
Authors: Walker Alexander M.
Published: August 2002

Information in claims databases resides in data patterns rather than in data elements. Finding this information requires new terminology, a willingness to pose questions of form rather than specific hypotheses, and a quality control system that elevates the correctness of data relations above the validity of single facts. The language of claims data is a newspeak of CPT (Current Procedural Terminology), HCPCS (Health Care Financing Agency Common Procedure Coding System), ICD (International Classification of Disease), and NDC (National Drug Codes) for pharmaceutical codes. The techniques of pattern discovery are really ways of asking the data for classes of relations, and they vary in their reliance on external information. Sometimes, the question is entirely constrained by preceding factors. Other times we may recast the natural history of disease into a claims context and ask the data to give us the shape of disease evolution. We can use highly automated systems to evaluate the relations between prespecified factors, or empirical techniques to search out common relations that we have not specified in advance. Using massive data sets requires that quality control corresponds to the nature of the high‐level information that we derive from large databases. Copyright © 2001 John Wiley & Sons, Ltd.
Photoinitiated cationic polymerization of epoxides
Authors: Decker Christian , Nguyen Thi Viet Trieu , Pham Thi Hong
Published: August 2002

Difunctional epoxy monomers have been polymerized cationically by UV irradiation in the presence of a triarylsulfonium photoinitiator. The curing process was followed quantitatively by monitoring the disappearance of the epoxy group by infrared spectroscopy and the insolubilization and hardening of the resin upon UV exposure. The addition of epoxidized soyabean oil (ESO) to an aromatic diepoxide was shown to accelerate the crosslinking reaction with formation of a tight polymer network. The photoinitiated copolymerization of ESO with a cycloaliphatic diepoxide proceeds extensively and leads within seconds to a fully cured insoluble material showing increased hardness, flexibility and scratch resistance. Interpenetrating polymer networks have been generated by a short UV‐irradiation of blends of acrylate and epoxy monomers.

© 2001 Society of Chemical Industry
A 21.5% efficient Cu(In,Ga)Se2 thin‐film concentrator solar cell
Authors: Ward J.S. , Ramanathan K. , Hasoon F.S. , Coutts T. J. , Keane J. , Contreras M.A. , Moriarty T. , Noufi R.
Published: August 2002

Cu(In,Ga)Se2 (CIGS) solar cells have been designed for operation under mildly concentrated sunlight. The absorber was deposited via a three‐stage evaporation process that has consistently yielded high‐performance one‐sun devices. The device structure reported here was modified by reducing the thickness of the CdS window/buffer layer to enhance the short‐circuit current at the expense of the open‐circuit voltage. Operation of the devices under optical enhancement leads to significant increases in the voltage and fill factor. At 14 suns, the open‐circuit voltage for this device was 736 mV, the fill factor was 80.5%, and the efficiency was 21.5%. This result represents the first report of a polycrystalline thin‐film solar cell with an efficiency in excess of 20%. Published in 2002 by John Wiley & Sons, Ltd.
The relationship between perceived social support and maladjustment for students at risk
Authors: Demaray Michelle Kilpatrick , Malecki Christine Kerres
Published: August 2002

This study examines the relationship between adolescents' (N = 125) perceived social support and self‐reported (mal)adjustment indicators in a sample of predominantly at risk: Hispanic students in an urban middle school. The instruments used to collect data were the Child and Adolescent Social Support Scale (Malecki, Demaray, & Elliott, 2000) and the Behavior Assessment System for Children, Self Report of Personality (Reynolds & Kamphaus, 1998). Results indicated significant relationships in the expected direction between overall social support and clinical and school (mal)adjustment indicators. Parent and classmate support were most strongly related to clinical and interpersonal indicators whereas parent, teacher, and school support were related to school‐related indicators. © 2002 Wiley Periodicals, Inc.
Good, bad, or in‐between: How does the daily behavior report card rate?
Authors: Chafouleas Sandra M. , Riley‐Tillman T. Chris , McDougal James L.
Published: August 2002

Our purpose here was to define and review the daily behavior report card (DBRC) as a monitoring and/or intervention technique. We considered a measure of a DBRC to be if a specified behavior was rated at least daily, and that information was shared with someone other than the rater. In general, it has been suggested that DBRCs may be feasible, acceptable, effective in promoting a positive student, and a way to increase parent/teacher communication. In addition, DBRCs are highly adaptive in that they represent a broad array of both monitoring and intervention possibilities rather than having a single, scripted purpose. All of these characteristics make the DBRC appealing for use in applied settings. However, an extensive, methodologically sound literature base does not yet exist. Despite the appeal of using DBRCs, widespread endorsement cannot be made without caution. We conclude with implications for use in practice and highlight areas in need of further investigation. © 2002 Wiley Periodicals, Inc.
Reducing problem behaviors on the playground: An investigation of the application of schoolwide positive behavior supports
Authors: Lewis Timothy J. , Powers Lisa J. , Kely Michele J. , Newcomer Lori L.
Published: August 2002

In an effort to reduce problem behavior, it is recommended that schools develop a continuum of positive behavior support (PBS) that focuses on prevention/early intervention as well as individualized student support systems for those students who display chronic problem behaviors. While there is a large database to support the use of PBS practices at the individual student level, the knowledge base supporting prevention/early intervention strategies is characterized as emerging. The purpose of this study was to investigate the efficacy of PBS prevention/early intervention strategies on the rate of problem behavior displayed by elementary school students during recess. Specifically, this study examined the effects of directly teaching playground‐related behaviors and the use of a group contingency to reinforce mastery in an elementary school. Results indicated that the intervention reduced the frequency of problem behavior across three recess periods. Results are discussed with respect to support of an emerging empirical database and implications for practice. © 2002 Wiley Periodicals, Inc.
Surveillance of school violence, injury, and disciplinary actions
Authors: Kingery Paul M. , Coggeshall Mark B.
Published: August 2002

The safety of America's schools is a major issue. Yet, the magnitude of the problem cannot be accurately assessed because some of the data concerning incidents and disciplinary actions come from reporting systems that are seriously flawed. In this article we examine how data from student self‐report surveys and other sources can be used to assess the weaknesses in current school incident‐reporting systems and improve the validity of surveillance data on school violence. Particular attention is paid to assessing the validity of data from Gun‐Free Schools Act (GFSA) reports on the number of guns in schools in light of nationally representative student survey data. We also discuss the difficulties of obtaining accurate surveillance data and suggest changes in surveillance systems that could produce more valid estimates of violence and injury in our nation's schools. © 2001 John Wiley & Sons, Inc.
Evaluating risk for targeted violence in schools: Comparing risk assessment, threat assessment, and other approaches
Authors: Reddy Marisa , Borum Randy , Berglund John , Vossekuil Bryan , Fein Robert , Modzeleski William
Published: August 2002

In the wake of recent school shootings, fear over violence in schools has prompted increased requests for psychologists, educators, and law enforcement professionals to assist in preventing future school violence incidents. We attempt to lay a foundation for developing effective assessment and prevention approaches by first distinguishing planned school‐based attacks from other forms of school and youth violence. We then review the three assessment approaches that have been advocated and used in some jurisdictions (profiling, guided professional judgment, automated decision‐making) and demonstrate why they are inappropriate—and potentially harmful—in preventing planned school‐based attacks. We then describe the contours of the threat assessment approach, developed by the U.S. Secret Service to prevent assassinations, and examine its utility for responding to communications or behaviors of concern that students may present in school settings. © 2001 John Wiley & Sons, Inc.
Reactions of carbon dioxide radical anion with substituted benzenes
Authors: Rosso Janina A. , Bertolotti Sonia G. , Braun André M. , Mártire Daniel O. , Gonzalez Mónica C.
Published: August 2002

We report mechanistic studies on the reactivity of CO2
.− radicals towards substituted benzenes, XPh, with X = NO2, COOH, COH, CH3, H, Cl and HO. Vacuum ultraviolet (VUV, 172 nm) irradiation of aqueous solutions containing formate was used as a method of CO2
.− radical generation for the study of the reaction products, which were determined by gas chromatography–mass spectrometry and high‐performance liquid chromatography. The nature of some of the reaction intermediates was studied by laser flash photolysis of aqueous solutions of peroxodisulfate in the presence of formate. The observed products and intermediates of reaction are discussed and rationalized by a dual reactivity of the CO2
.− radical anion with substituted benzenes: a one‐electron reduction and radical addition to the aromatic ring. For substituted benzenes with X = NO2, COOH and COH, the observed products support an electron transfer from CO2
.− to the substrates as the primary reaction channel, while the reactions with toluene follow the channel of radical addition. Benzene and chlorobenzene react with CO2
.− by both routes, electron transfer and radical addition. Our experimental results indicate that H abstraction by the CO2
.− radical is negligible under the chosen experimental conditions. Copyright © 2001 John Wiley & Sons, Ltd.
Preparation and characterization of soluble terpolymers from m‐phenylenediamine, o‐anisidine, and 2,3‐xylidine
Authors: Li Xin‐Gui , Duan Wei , Huang Mei‐Rong , Yang Yu‐Liang
Published: August 2002

A series of terpolymers were synthesized by the chemical oxidative polymerization of m‐phenylenediamine (MPD), o‐anisidine (AS), and 2,3‐xylidine (XY) in hydrochloride aqueous medium. The yield, intrinsic viscosity, and solubility of the terpolymers were studied by changing the MPD/AS/XY molar ratio from 100/0/0 to 53/39/8 to 0/100/0. It was discovered that the MPD/AS/XY terpolymers exhibit a higher polymerization yield and better solubility than MPD/AS and MPD/XY bipolymers having the same MPD molar content. The as‐prepared MPD/AS/XY terpolymer bases were characterized by Fourier transform infrared, ultraviolet–visible, 1H NMR, and high‐resolution solid‐state 13C NMR spectroscopies; wide‐angle X‐ray diffraction; and thermogravimetry. The results suggested that the oxidative polymerization from MPD, AS, and XY is exothermic, and the resulting terpolymers are more easily soluble in some organic solvents than MPD homopolymer. The copolymer obtained was a real terpolymer containing MPD, AS, and XY units, and the actual MPD/AS/XY molar ratio calculated by solid‐state 13C NMR spectra of the polymers is very close to the feed ratio, although the AS content calculated on the basis of the 1H NMR spectrum of the soluble part of the polymer is higher than the feed AS content. The terpolymers and MPD homopolymer exhibit a higher polymerization yield and much higher intrinsic viscosity and are more amorphous than the AS homopolymer. At a fixed MPD content of 70 mol %, the terpolymers exhibit an increased thermostability and activation energy of the major degradation in nitrogen and air with an increasing AS content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3989–4000, 2001