bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of eyespot resistance genes on baking quality and yield in wheat
Authors: Koen Elizma , Labuschagne Maryke T , Viljoen Chris D
Published: October 2002

In a backcross programme to introduce resistance genes, the retention of genes other than the resistance gene from the donor parent is possible owing to either chance, the simultaneous transfer of linked genes, incomplete compensation of replaced wheat chromatin, or other crossover segments being incorporated into the wheat genotype. This may cause unwanted characteristics in resistant cultivars. Eyespot in wheat is caused by Pseudocercosporella herpotrichoides (Fron) Deighton. This disease is widely spread throughout the world and can result in severe damage to wheat crops. Genetic control of the disease has been found to be very effective. The aim of this study was to determine the effect of the Pch1 eyespot resistance gene, backcrossed 8–10 times into South African wheat cultivars SST66 and Palmiet, on baking quality and yield in the absence of the disease. The presence of the gene had a detrimental effect on thousand‐kernel mass in two SST66 lines and on yield in one Palmiet line, but there were no detrimental effects on any measured quality characteristics. The presence of the gene will thus protect the plant from the disease without having a negative effect on baking quality.

© 2002 Society of Chemical Industry
Laser assisted delivery of topical anesthesia for intramuscular needle insertion in adults
Authors: Shapiro Howard , Harris Lisbeth , Hetzel Fred W. , Bar‐Or David
Published: October 2002

Background and Objectives

Currently there is no safe, effective, and rapid means to eliminate the pain associated with a needle insertion through the skin. It is hypothesized that ablation of the stratum corneum layer using a low energy Erbium(Er):YAG laser would allow rapid local anesthesia from a lidocaine product.

Study Design/Materials and Methods

Eighty volunteers participated in a placebo‐controlled, double blind, cross‐over study employing the Norwood–Abbey (Chelsea Heights, Victoria, Australia) laser anesthesia device (LAD) and two lidocaine preparations. Upper‐arm skin ablation was followed by a 5‐minute application of study treatment. Pain scores were registered immediately following a needle insertion.

Results

Comparing the combined lidocaine preparations to placebo, there was a statistically significant reduction in pain when the LAD was employed (P < 0.001). The median pain reduction for lidocaine was 51.3% (95% CI = [40.9, 76.1]).

Conclusions

Use of the low energy Er:YAG LAD device in combination with a 5‐minute application of lidocaine significantly reduced the pain associated with a needle insertion. Lasers Surg. Med. 31:252–256, 2002. © 2002 Wiley‐Liss, Inc.
Effect of low‐power laser irradiation on cell growth and procollagen synthesis of cultured fibroblasts
Authors: Pereira Aymann Nassif , Eduardo Carlos de Paula , Matson Edmir , Marques Márcia Martins
Published: October 2002

Background and Objectives

In dentistry, low‐power lasers have been used in the treatment of dentin hypersensitivity, gingivitis, periodontitis, and different forms of oral ulcers. This in vitro study focuses on the biostimulation of NIH‐3T3 fibroblasts by a low‐power Ga–As‐pulsed laser.

Study Design/Materials and Methods

We have studied cell growth and procollagen synthesis of cultured fibroblasts submitted to low‐power laser irradiation with energy densities varying from 3 to 5 J/cm2 over a period of 1–6 days. The light source was a 120 mW Ga–As diode laser (λ = 904 nm). Growth curves and procollagen immunoprecipitation were obtained.

Results

Irradiation of 3 and 4 J/cm2 increased the cell numbers about threefold to sixfold comparing to control cultures. However, this effect was restricted to a small range of energy densities since 5 J/cm2 had no effect on cell growth. The energy density of 3 J/cm2 remarkably increased cell growth, with no effect on procollagen synthesis, as demonstrated by the immunoprecipitation analysis.

Conclusions

Our results showed that a particular laser irradiation stimulates fibroblast proliferation, without impairing procollagen synthesis. Lasers Surg. Med. 31:263–267, 2002. © 2002 Wiley‐Liss, Inc.
Photodynamic therapy of high‐grade cervical intraepithelial neoplasia with 5‐aminolevulinic acid
Authors: Keefe Kristin A. , Tadir Yona , Tromberg Bruce , Berns Michael , Osann Kathryn , Hashad Rasha , Monk Bradley J.
Published: October 2002

Background and Objectives

To determine the safety and efficacy of 5‐aminolevulinic acid (ALA) as a topically applied photosensitizer for photodynamic therapy (PDT) of cervical intraepithelial neoplasia (CIN).

Study Designs/Materials and Methods

Forty women, who were at least 18 years old with persistent biopsy‐proven CIN 2 and CIN 3 within the previous 3 months of enrollment, underwent PDT in a phase I and II design. Five escalating radiant energies (increments of 25 J/cm2, beginning at 50–150 J/cm2) using a Coherent Dye Model 920 argon pumped dye laser providing light at 630 nm (maximum output 0.8 W) were used to perform PDT with a fixed dose of ALA (200 mg/ml). ALA was placed in a cervical cap fitted to the cervix. After 90 minutes, the cap was removed and the ectocervix was illuminated for 5–16 minutes, depending on the irradiance. Success was defined as the absence of CIN on Pap smear or colposcopic examination at 12‐months. Patients were monitored for toxicity.

Results

Thirty‐two women (80%) completed the study with 1 year of follow‐up. Sixty percent had CIN 3 and 40% CIN 2. Success rates at 4, 8, and 12 months were 51, 46, and 31%, respectively, and were not light‐dose dependent. Three patients progressed from CIN 2 to CIN 3. Toxicity was tolerable and only consisted of spotting, vaginal discharge, mild cramping, and vaginal warmth. There was no apparent dose relationship to toxicity.

Conclusions

PDT at this light and ALA dose is well tolerated but has minimal activity in the treatment of CIN 2 and CIN 3. Other doses and schedules of light and ALA or novel photosensitizers may improve efficacy. Lasers Surg. Med. 31:289–293, 2002. © 2002 Wiley‐Liss, Inc.
Applications of pulsed ultrafiltration‐mass spectrometry
Authors: Johnson Benjamin M. , Nikolic Dejan , van Breemen Richard B.
Published: October 2002

I.
Introduction
76

II.
Screening Applications
77

A.  Ligand‐Screening Assays
77

B.  Characterization of Ligand–Protein Binding
81

C.  Metabolic Screening
81

D.  Screening for Electrophilic Metabolites
83

III.
Conclusions
84

Acknowledgments
85

References
85

Pulsed ultrafiltration‐mass spectrometry (PUF‐MS) is a method with a variety of uses for the discovery and development of biologically active small molecules, including the screening of combinatorial libraries and natural product extracts for biologically active compounds, investigation of thermodynamic and kinetic ligand–receptor binding parameters, high‐throughput metabolic screening, and the screening of combinatorial libraries and botanical extracts for electrophilic metabolites. Solution‐phase ligand‐screening assays that use pulsed ultrafiltration‐mass spectrometry are useful for “reverse pharmacology” studies in which a macromolecular receptor of interest has been isolated, but ligands for the receptor are needed. Protein‐binding studies that involve pulsed ultrafiltration can be used to rapidly determine classical binding parameters for interactions between a macromolecular receptor and a compound of interest. Metabolic screening assays can identify substrates for cytochromes P450, and should be capable of characterizing phase I metabolites with a throughput of at least 60 compounds/hr. Pulsed ultrafiltration can also be used in conjunction with LC‐MS‐MS to screen mixtures for compounds that might be activated metabolically to electrophilic quinoid and epoxide metabolites by cytochrome P450; that screening can provide early warning of compounds likely to be toxic when administered in large doses. The combination of pulsed‐ultrafiltration extraction and mass spectrometric detection provides the sensitivity and selectivity necessary to characterize compounds present at low concentrations in complex chemical mixtures, and is applicable to the analysis of biologically active compounds from combinatorial libraries and botanical extracts. © 2002 Wiley Periodicals, Inc., Mass Spec Rev 21:76–86, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mas.10020
Excessive daytime sleepiness in de novo and treated Parkinson's disease
Authors: Fabbrini Giovanni , Barbanti Piero , Aurilia Cinzia , Vanacore Nicola , Pauletti Caterina , Meco Giuseppe
Published: October 2002

Excessive daytime sleepiness (EDS) in Parkinson's disease (PD) is due to either treatment‐related factors or the disease itself. The study of this disturbing phenomenon in de novo parkinsonian patients may contribute to a better understanding of its pathophysiology. We conducted a case control study in which we compared 25 PD patients who had never been treated before with dopaminergic drugs (de novo PD), 50 PD patients being treated with dopaminergic drugs (treated PD), and 25 healthy control subjects, all of whom were matched for age and gender. EDS was measured by means of the Epworth Sleepiness Scale (ESS) and quality of sleep by means of the Pittsburgh Sleep Quality Index (PSQI). ESS and PSQI scores were not statistically different between de novo PD patients and controls, whereas they were significantly higher in treated PD. Differences in ESS score variability were best explained by the treatment effect, whereas there was no clear correlation between PSQI and any of the clinical variables considered. © 2002 Movement Disorder Society
Cognitive functioning in neurologically symptomatic and asymptomatic forms of Wilson's disease
Authors: Seniόw Joanna , Bak Thomas , Gajda Jolanta , Poniatowska Renata , Czlonkowska Anna
Published: October 2002

We sought to determine the pattern of cognitive deficits in patients with Wilson's disease (WD) with different type and degree of neurological involvement, and to interpret the findings in relation to the underlying pathology. A total of 67 WD patients were examined with a neuropsychological test battery assessing different aspects of cognitive processing. The patients were subdivided into three groups: neurologically asymptomatic, neurological with pure basal ganglia lesions, and neurological with more extensive pathology. The results were compared with 50 matched healthy controls. Patients with a neurological form of WD showed a mild but definitive impairment in all cognitive functions. In contrast, the neurologically asymptomatic patients showed no deficits when compared with normal controls. Multifocal pathology was associated with more severe cognitive deficits than selective basal ganglia lesions but did not contribute significantly to memory impairment. A range of cognitive functions, including frontal‐executive ability, aspects of memory and visuospatial processing, are affected in the neurologically symptomatic WD patients. In contrast, no subliminal deficits were observed in the asymptomatic patients. The lesions of the basal ganglia seem to be of central importance in explaining the symptomatology. © 2002 Movement Disorder Society
Clinical correlates of the pathology underlying parkinsonism: A population perspective
Authors: Bower James H. , Dickson Dennis W. , Taylor Laura , Maraganore Demetrius M. , Rocca Walter A.
Published: October 2002

We correlated the clinical features with pathological findings in an autopsy series of cases of incident parkinsonism. We used the medical records‐linkage system of the Rochester Epidemiology Project to identify all incident cases of parkinsonism in Olmsted County, MN, for the years 1976 to 1990. Medical histories were abstracted in a standardized manner. Included in this study were those incident cases who died and underwent autopsy. Brain sections were studied with routine histology and special stainings. A neuropathologist blinded to any clinical information assigned cases to neuropathological categories. We found 364 incident cases of parkinsonism of which 235 were deceased at the time of this study; there were 39 autopsied brains available for analysis (17% of deceased cases). Of the 16 patients diagnosed pathologically with Lewy body disease, documentation indicated that 8 had an early dementia, 3 had prominent dysautonomia, and 2 had prominent ataxia. Of the 7 patients diagnosed pathologically with progressive supranuclear palsy, 4 had no documentation of supranuclear gaze palsy, and 3 had no documentation of early falls. Of the 3 patients diagnosed pathologically with multiple system atrophy, none had prominent ataxia or dysautonomia documented. Of the 5 patients with vascular disease at pathology, none had been given the clinical diagnosis of vascular parkinsonism. Of the 8 cases given the clinical diagnosis of drug‐induced parkinsonism, 6 were found to have basal ganglia pathology. The autopsied cases in this study were not representative of all patients with parkinsonism, because atypical cases are more likely to come to autopsy than typical ones. Despite this selection bias, the retrospective data collection, and the small sample size, we made several observations that illustrate the difficulty in achieving an accurate antemortem diagnosis of parkinsonism. © 2002 Movement Disorder Society
The monoamine reuptake blocker brasofensine reverses akinesia without dyskinesia in MPTP‐treated and levodopa‐primed common marmosets
Authors: Pearce Ronald K.B. , Smith Lance A. , Jackson Michael J. , Banerji Tara , Scheel‐Krüger Jorgen , Jenner Peter
Published: October 2002

The common marmoset develops motor deficits after MPTP treatment and exhibits dyskinesia after chronic levodopa (L‐dopa) dosing and subsequent re‐challenge with L‐dopa and other dopaminergic agents. We report on the actions of the potent monoamine reuptake blocker brasofensine on motor disability, locomotor activity, and dyskinesia in the 1‐methyl‐4‐1, 2,3,6‐tetrahydropyridine (MPTP) ‐treated marmoset model of Parkinson's disease. Oral administration of brasofensine (0.25, 0.5, 1.0, or 2.5 mg/kg) to MPTP‐treated marmosets produced a long‐lasting, dose‐dependent increase in locomotor activity and reduction in disability scores. In addition, coadministration of the lowest dose of brasofensine (0.25 mg/kg orally) with a threshold oral dose of L‐dopa (2.5 mg/kg) caused a marked increase in locomotor activity, greater than that produced by either drug alone. In other MPTP‐treated marmosets previously primed to exhibit dyskinesia by repeated L‐dopa dosing, brasofensine effectively reversed akinesia with a naturalistic and prolonged motor response without the appearance of dyskinesia or stereotypy. This finding contrasts with the severe dyskinesia, stereotypy, and hyperkinesis produced by equivalent doses of L‐dopa. The ability of brasofensine to produce a prolonged and naturalistic antiparkinsonian response without eliciting dyskinesia after previous L‐dopa priming may relate to actions on D1 receptor‐linked pathways. These findings suggest that monoamine reuptake blockade may be of value in the treatment of Parkinson's disease, both early in the disease course and when L‐dopa–induced dyskinesias complicate treatment. © 2002 Movement Disorder Society
The equations of non‐homogeneous asymmetric fluids: an iterative approach
Authors: Conca Carlos , Gormaz Raúl , Ortega‐Torres Elva E. , Rojas‐Medar Marko A.
Published: October 2002

We study the existence and uniqueness of strong solutions for the equations of non‐homogeneous asymmetric fluids. We use an iterative approach and we prove that the approximate solutions constructed by this method converge to the strong solution of these equations. We also give bounds for the rate of convergence. Copyright © 2002 John Wiley & Sons, Ltd.
Cofired laminated ceramic package antenna for single‐chip wireless transceivers
Authors: Zhang Y. P. , Do M. A.
Published: October 2002

A novel concept for implementing an antenna on an integrated circuit package is proposed for the single‐chip solution of a wireless transceiver with the use of deep submicron CMOS technology. The prototype antenna printed on a 40–p‐i‐n dual‐in‐line cofired laminated ceramic package is experimentally studied at 3.45 GHz. The results show that the antenna has achieved a bandwidth of 25.1% and a gain of −2.0 dBi. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 14–16, 2002; DOI 10.1002/mop.10216
Planar monopole folded into a compact structure for very‐low‐profile multiband mobile‐phone antenna
Authors: Teng Pey‐Ling , Wong Kin‐Lu
Published: October 2002

A planar monopole consisting of three branch strips and folded into a rectangular‐box‐like compact structure for very‐low‐profile GSM/DCS/PCS multiband mobile‐phone antennas is presented. The three branch strips are designed to operate as quarter‐wavelength structures at 900, 1800, and 1900 MHz, respectively, and the obtained impedance bandwidths cover the required bandwidths of the GSM band (890–960 MHz), the DCS band (1710–1880 MHz), and the PCS band (1850–1990 MHz). The proposed antenna has a compact size of 6.5 mm in height, 6 mm in width, and 25 mm in length, and can be mounted on top of a mobile phone with a small distance of 3 mm to the ground plane, resulting in a very low profile of 9.5 mm (less than 3% of the wavelength at 900 MHz) from ground for the proposed antenna in practical applications. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 22–25, 2002; DOI 10.1002/mop.10219
A model for the number of independent samples in reverberation chambers
Authors: Hallbjörner Paul
Published: October 2002

Antenna efficiency measurements in reverberation chambers are done by averaging a number of sampled power levels, measured while the mode stirrer rotates. The number of independent samples is the number of stirrer positions that give uncorrelated fields in the chamber, and thereby uncorrelated power levels. A larger number of samples gives a better accuracy of the measured value. This report presents a proposed theoretical model for the number of independent samples of a reverberation chamber, thereby giving a better understanding of how to optimize a chamber design. Measured data from chambers with three different types of stirrers are compared with the use of the model. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 25–28, 2002; DOI 10.1022/mop.10220
A parallel implementation of an evolutionary‐based automatic tool for microwave circuit synthesis: Preliminary results
Authors: Caorsi Salvatore , Donelli Massimo , Massa Andrea , Raffetto Mirco
Published: October 2002

In this paper a CAD tool for the automatic design of passive microwave components is described. It is based on a genetic algorithm optimizer and a three‐dimensional finite element simulator. The main feature of the proposed tool is its ability, achieved by means of the parallel virtual machine software package, to fully exploit any concurrent computational resource. The effectiveness of the proposed approach is preliminarily assessed by considering the synthesis of a rectangular waveguide power divider. Selected numerical results confirm the capabilities, but also the current limitations, of the presented methodology. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 169–172, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10547
Antenna integration with a waveguide photodetector for high capacity wireless communications
Authors: Khodier Majid M. , Christodoulou Christos G. , Liao Tsai S. , Yu Paul K. L.
Published: October 2002

This paper proposes the integration of an antenna with a photodetector for high capacity wireless communications. A waveguide photodetector (WGPD), illuminated on the side, is used to convert the RF‐modulated optical power into a microwave signal. That microwave signal is used to feed an antenna built on the same plane as the photodetector. The WGPD is a standard p‐i‐n device grown on a semi‐insulating InP. The performance of this RF/photonic antenna in the frequency range 17–20 GHz is studied theoretically and experimentally. An equivalent circuit model for the WGPD is developed to predict the photodetector impedance as a function of frequency. The photodetector is matched to the input impedance of the antenna. The agreement between measurement and the circuit model results for the WGPD impedance is very good. It is envisioned that a large number of such RF/Photonic antenna elements could be networked together into a star configuration, feeding in and out of a radio hub. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 179–184, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10550
Power characteristics of dielectric optical Piet Hein waveguides
Authors: Choudhury P. K.
Published: October 2002

A fairly rigorous analytical treatment of the power characteristics of dielectric optical waveguides with Piet Hein core‐cross sectional geometry is presented in this paper. This kind of waveguide structure would be advantageous owing to the absence of corners, which are found in rectangular guides, resulting in undesirable loss due to the scattering of light. In order to simplify this theoretical approach, an approximation of vanishing refractive index difference between the guiding and the non‐guiding sections is implemented. The variation of logarithmic power is shown for different dimensions of the core, corresponding to different azimuthal modal indices. It is found that the modes with higher index values carry less logarithmic power in the lower tail of the propagation's constant range, and this feature affects the higher tail. A better kind of uniformity of the power distribution is observed near the higher tail of the range of propagation constants. This feature would lead to useful applications of these guides in integrated optic technology. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 236–240, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10567
A fast iterative physical optics (FIPO) algorithm based on non‐uniform polar grid interpolation
Authors: Boag Amir
Published: October 2002

In this paper, a novel fast iterative physical optics (FIPO) algorithm is proposed for analysis of scattering from electrically large objects involving multiple reflections such as the case for open‐ended cavities. At each iteration, the physical optics current induced on the surface of the scatterer produces a correction to the incident field, which in turn induces a correction to the physical optics current. The FIPO algorithm relies on fast field evaluation, which is achieved via domain decomposition of the scatterer surface and comprises two steps repeated for each subdomain. First, computation of the field is produced by currents residing within a subdomain over a sparse set of points surrounding the scatterer. Second, phase removal, interpolation, phase restoration, and aggregation of the field of the subdomain are integrated into the total field on the surface. The proposed approach can be extended to fast iterative solution of problems discretized via the method of moments. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 240–244, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10568
Thallium(III) coordination compounds: chemical information from 205Tl NMR longitudinal relaxation times
Authors: Bodor Andrea , Bányai István , Kowalewski Jozef , Glaser Julius
Published: October 2002

205Tl longitudinal relaxation rate measurements were performed on several thallium(III) complexes with the composition Tl(OH)n(H2O)6−n(3−n)+ (n = 1,2), Tl(Cl)n(H2O)m−n(3−n)+, Tl(Br)n(H2O)m−n(3−n)+ (m = 6 for n = 1–2, m = 5 for n = 3, m = 4 for n = 4), Tl(CN)n(H2O)m−n(3−n)+ (m = 6 for n = 1–2, m = 4 for n = 3–4) in aqueous solution, at different magnetic fields and temperatures. 13C and 2D isotopic labelling and 1H decoupling experiments showed that the contribution of the dipolar relaxation path is negligible. The less symmetric lower complexes (n < 4) had faster relaxation rate dominantly via chemical shift anisotropy contribution which depended on the applied magnetic field: T1 values are between 20 and 100 ms at 9.4 T and the shift anisotropy is Δσ = 1000–2000 ppm. The tetrahedral complexes, n = 4, relax slower; their T1 is longer than 1 s and the spin–rotation mechanism is probably the dominant relaxation path as showed by a temperature dependence study. In the case of the TlCl4− complex, presumably a trace amount of TlCl52− causes a large CSA contribution, 300 ppm. Since the geometry and the bond length for the complexes in solution are known from EXAFS data, it was possible to establish a correlation between the CSA parameter and the symmetry of the complexes. The relaxation behaviour of the Tl–bromo complexes is not in accordance with any known relaxation mechanism. Copyright © 2002 John Wiley & Sons, Ltd.
Evidence that anandamide‐signaling regulates human sperm functions required for fertilization
Authors: Schuel Herbert , Burkman Lani J. , Lippes Jack , Crickard Kent , Mahony Mary C. , Giuffrida Andrea , Picone Robert P. , Makriyannis Alexandros
Published: October 2002

Ejaculated mammalian sperm require several hours exposure to secretions in female reproductive tracts, or incubation in appropriate culture medium in vitro, before acquiring the capacity to fertilize eggs. Arachidonylethanolamide (AEA), also known as anandamide, is a novel lipid‐signal molecule that is an endogenous agonist (endocannabinoid) for cannabinoid receptors. We now report that AEA is present in human seminal plasma, mid‐cycle oviductal fluid, and follicular fluid analyzed by high‐performance liquid chromatography/mass spectrometry. Sperm are sequentially exposed to these reproductive fluids as they move from the vagina to the site of fertilization in the oviduct. Specific binding of the potent cannabinoid agonist [3H]CP‐55,940 to human sperm was saturable (KD 9.71 ± 1.04 nM), suggesting that they express cannabinoid receptors. R‐methanandamide [AM‐356], a potent and metabolically stable AEA analog, and (−)Δ9 tetrahydrocannabinol (THC), the major psychoactive constituent of Cannabis, modulated capacitation and fertilizing potential of human sperm in vitro. AM‐356 elicited biphasic effects on the incidence of hyperactivated sperm motility (HA) between 1 and 6 hr of incubation: at (2.5 nM) it inhibited HA, while at (0.25 nM) it stimulated HA. Both AM‐356 and THC inhibited morphological alterations over acrosomal caps between 2 and 6 hr (IC50 5.9 ± 0.6 pM and 3.5 ± 1.5 nM, respectively). Sperm fertilizing capacity, measured in the Hemizona Assay, was reduced 50% by (1 nM) AM‐356. These findings suggest that AEA‐signaling may regulate sperm functions required for fertilization in human reproductive tracts, and imply that smoking of marijuana could impact these processes. This study has potential medical and public policy ramifications because of the incidence of marijuana abuse by adults in our society, previously documented reproductive effects of marijuana, and the ongoing debate about medicinal use of marijuana and cannabinoids. Mol. Reprod. Dev. 63: 376–387, 2002. © 2002 Wiley‐Liss, Inc.
Reduction of flow‐related signal loss in flow‐compensated 3D TOF MR angiography, using variable echo time (3D TOF‐VTE)
Authors: Jeong Eun‐Kee , Parker Dennis L. , Tsuruda Jay S. , Won Jong‐Yun
Published: October 2002

High‐resolution MRA with phase/frequency flow compensation may require very long echo times (TEs). Variable TE (VTE) was implemented into flow‐compensated 3D TOF to minimize the effective TE and reduce the flow‐related signal void. Thek‐space of the 3D TOF was divided into segment groups ranging from two to 32 segments with different TEs. The TEs were minimized and the flow‐compensation gradient lobes were calculated to null the total first moment at the peak of the echo for each segment. Possible artifacts and off‐resonance effects were evaluated, with respect to the number of TE segments, using the point spread function (PSF) and corresponding experiments. The optimal number of TE segments for the least artifact was determined to be one‐half of the number of slices. Two types of artifacts caused by VTE were predicted and subsequently observed. The developed pulse sequence 3D TOF‐VTE was tested on clinical MRI systems, by performing scans of the cervical carotid artery and intracranial carotid artery at the carotid siphon. The signal distribution near the bifurcation and the siphon was much more uniform with VTE, and the flow‐related signal loss was greatly reduced. The resultant MR angiograms provided improved vessel detail. The results show that VTE improved the quality of flow‐compensated 3D TOF MRA. Magn Reson Med 48:667–676, 2002. © 2002 Wiley‐Liss, Inc.
Improved white matter fiber tracking using stochastic labeling
Authors: Tench C.R. , Morgan P.S. , Blumhardt L.D. , Constantinescu C.
Published: October 2002

Diffusion tensor imaging (DTI) promises a robust means of visualizing in vivo white matter fibers in individual subjects, and of inferring direct connectivity between distant points in the brain. By following the primary eigenvector of the diffusion tensor, trajectories may be defined that trace the path of the underlying fiber tract. However, fiber tracking is prone to cumulative error from acquisition noise and partial volume, which limits the repeatability of such techniques. An image‐processing method based on stochastic labeling, by which the noisy primary eigenvectors may be reconfigured according to anatomically reasonable assumptions, is described. The method's potential to improve fiber tracking is first demonstrated on numerical test data. It is then applied to real data acquired from healthy volunteers. Trajectories defined within the corpus callosum and the pyramidal tracts are rendered using 3D graphic imaging software, and the results are compared before and after processing. Fiber tracking was shown to produce anatomically plausible results, and typical errors were largely resolved by the method. Further, the sensitivity of trajectories to their start point was greatly reduced after processing. The use of stochastic labeling may therefore improve the reliability of experiments using white matter fiber tracking. Magn Reson Med 48:677–683, 2002. © 2002 Wiley‐Liss, Inc.
Regularized higher‐order in vivo shimming
Authors: Kim Dong‐Hyun , Adalsteinsson Elfar , Glover Gary H. , Spielman Daniel M.
Published: October 2002

A regularized algorithm is presented for localized in vivo shimming. The technique uses first‐ (X,Y,Z), second‐ (Z2, ZX, ZY, X2‐Y2, XY), and third‐order (Z3) shim coils, and is robust when applied to arbitrarily‐shaped, as well as off‐center, regions of interest (ROIs). A single‐shot spiral pulse sequence is used for rapid field map acquisition, and a least‐squares calculation of the shim currents is performed to minimize the root‐mean‐square (RMS) value of the B0 inhomogeneity over a user‐selected ROI. The use of a singular value decomposition (SVD) in combination with a regularization algorithm significantly improves the numerical stability of the least‐squares fitting procedure. The fully automated shimming package is implemented on a 3 T GE Signa system and its robust performance is demonstrated in phantom and in vivo studies. Magn Reson Med 48:715–722, 2002. © 2002 Wiley‐Liss, Inc.
Comparison of collagen dynamics in articular cartilage and isolated fibrils by solid‐state NMR spectroscopy
Authors: Huster Daniel , Schiller Jürgen , Arnold Klaus
Published: October 2002

Native pig articular cartilage was investigated by 13C cross polarization (CP) magic angle spinning (MAS) NMR at a magnetic field strength of 17.6 T. CP MAS spectra of cartilage are dominated by resonances from rigid collagen, while only low‐intensity signals from the glycosaminoglycans are observed. The spectral resolution of collagen fibrils in native cartilage is somewhat higher than for isolated collagen fibrils from bovine achilles tendon investigated for comparison. This is confirmed qualitatively by 1H‐1H wideline separation spectra that show much lower line widths for cartilage collagen compared to isolated collagen. The strength of 1H‐13C dipolar couplings was measured in a 2D LG CP experiment providing a motionally averaged dipolar coupling value for each resolved signal. These scaled couplings were converted to molecular order parameters for the CH bond vector. Typical order parameters for isolated collagen were 0.91–0.96 for sidechains and 0.98–1.00 for the backbone. Somewhat lower order parameters were determined for cartilage collagen; 0.79–0.90 for the sidechain and 0.92–0.97 for the backbone. The only glycosaminoglycan signals that could be detected by CP MAS show order parameters of 0.48–0.92 and are assigned to relatively rigid hyaluronan and keratan sulfate. The higher mobility of collagen in cartilage is due to the high water content and collisions with the isotropically mobile glycosaminoglycans, such as chondroitin sulfate. Therefore, the mobility of cartilage macromolecules is broadly distributed from almost completely rigid to highly mobile, which lends cartilage its mechanical strength and shock‐absorbing properties. Magn Reson Med 48:624–632, 2002. © 2002 Wiley‐Liss, Inc.
Phenotypic variability among first‐degree relatives with carnitine palmitoyltransferase II deficiency
Authors: Vladutiu Georgirene D. , Bennett Michael J. , Fisher Nadine M. , Smail David , Boriack Richard , Leddy John , Pendergast David R.
Published: October 2002

Carnitine palmitoyltransferase (CPT) II deficiency disorders are clinically very variable. To examine the cause(s) of variable symptoms in first‐degree relatives with CPT II deficiency, four sisters with various combinations of mutations and polymorphisms in the CPT2 gene were studied, together with 20 sedentary and 24 trained healthy female subjects. One sister, whose symptoms began at age 7 years, was more severely affected than her older sister, whose symptoms began at age 16 years; both were compound heterozygotes for the common S113L mutation and Q413fs, and for the common CPT2 polymorphisms, V3681 and M647V. A third sister became hypoglycemic with fasting, was heterozygous for the S113L mutation, and homozygous for the polymorphism variants. The fourth sister was asymptomatic, heterozygous for the Q413fs mutation, and homozygous for the normal polymorphisms. Residual CPT II activity in skeletal muscle and cultured skin fibroblasts from the two myopathic sisters, and palmitate oxidation in fibrobasts, were abnormally low; cellular and total body fat oxidation were also diminished. Muscle function and fat oxidation were nomal at rest, but a switch to carbohydrate utilization occurred at lower exercise intensities than in sedentary and trained individuals, respectively. Reliance on carbohydrates during stress and hormonal alterations may explain, in part, the variance in ages of onset and serverity of symptoms in myopathic patients. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 492–498, 2002
Parameter identification for lined tunnels in a viscoplastic medium
Authors: Lecampion B. , Constantinescu A. , Nguyen Minh D.
Published: October 2002

This paper is dedicated to the identification of constitutive parameters of elasto‐viscoplastic constitutive law from measurements performed on deep underground cavities (typically tunnels). This inverse problem is solved by the minimization of a cost functional of least‐squares type. The exact gradient is computed by the direct differentiation method and the descent is done using the Levenberg–Marquardt algorithm. The method is presented for lined or unlined structures and is applied for an elastoviscoplastic constitutive law of the Perzyna class. Several identification problems are presented in one and two dimensions for different tunnel geometries. The used measurements have been obtained by a preliminary numerical simulation and perturbed with a white noise. The identified responses match the measurements. We also discuss the usage of the sensitivity analysis of the system, provided by the direct differentiation method, for the optimization of in situ monitoring. The sensitivity distribution in space and time assess the location of the measurements points as well as the time of observation needed for reliable identification. Copyright © 2002 John Wiley & Sons, Ltd.
A complex variable solution for a deforming buoyant tunnel in a heavy elastic half‐plane
Authors: Strack O.E. , Verruijt A.
Published: October 2002

An analytical solution is presented for a buoyant tunnel in an elastic half‐plane. The tunnel undergoes a prescribed displacement along its boundary, and the surface of the half‐plane is stress‐free. The solution uses the complex variable method and consists of conformally mapping the hole and half‐plane to an annular region. The complex potentials each contain two logarithmic terms due to the resultant buoyancy force acting on the tunnel, and as a result the displacements at infinity are unbounded. An example is presented for the case of a rigid buoyant tunnel in a half‐plane with gravity loading. Even though the tunnel does not deform, the buoyancy effect can be clearly seen in the contours of the displacements and stresses. Copyright © 2002 John Wiley & Sons, Ltd.
An index policy for a stochastic scheduling model with improving/deteriorating jobs
Authors: Glazebrook K.D. , Mitchell H.M.
Published: October 2002

We consider stochastic scheduling models which have the natural character that jobs improve while being processed, but deteriorate (and may possibly leave the system altogether) while processing is diverted elsewhere. Such restless bandit problems are shown to be indexable in the sense of Whittle. A numerical study which elucidates the strong performance of the resulting index policy is complemented by a theoretical study which demonstrates the optimality of the index policy under given conditions and which develops performance guarantees for the index heuristic more generally. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 706–721, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10036
Network fair bandwidth share using hash rate estimation
Authors: Li Jung‐Shian , Leu Ming‐Shiann
Published: October 2002

In this paper, we evaluate the effectiveness of the current active queue management (AQM) schemes, such as Random Early Detection (RED) and match‐based CHOKe, over traffic with different packet‐size flows and over traffic with mixed adaptive and nonadaptive flows. We find that these schemes allow unfair bandwidth sharing when flows with different packet sizes share a link or when numerous adaptive and nonadaptive flows coexist in a link. In particular, the match‐based schemes present greater unfairness, especially when more nonadaptive flows exist in a shared link. We propose a novel AQM scheme, called Hash Rate Estimation (HRE). The proposed scheme, which works with a FIFO queue, uses per‐active‐flow rate estimation to impose a fair share on each flow. We show that HRE provides better protection than does Fair Random Early Drop (FRED), which uses per‐flow accounting to allocate each flow its fair share by a fixed dropping probability that depends on the flow's buffer use. HRE can support a large number of flows using hash function sorting. In addition, the queue length under HRE is bounded and the characteristics of traffic regulated by HRE are similar to those achieved by the per‐flow fair queuing schemes. © 2002 Wiley Periodicals, Inc.
Isomorphisms of the De Bruijn digraph and free‐space optical networks
Authors: Coudert D. , Ferreira A. , Perennes S.
Published: October 2002

The de Bruijn digraph B(d, D) has degree d, diameter D, dD vertices, and dD+1 arcs. It is usually defined by words of size D on an alphabet of cardinality d, through a cyclic left‐shift permutation on the words, after which the rightmost symbol is changed. In this paper, we show that any digraph defined on words of a given size, through an arbitrary permutation on the alphabet and an arbitrary permutation on the word indices, is isomorphic to the de Bruijn digraph, provided that this latter permutation is cyclic. We use this result to improve from O(dD+1) to
$\Theta(\sqrt{d^{D+1}})$
the number of lenses required for the implementation of B(d, D) by the Optical Transpose Interconnection System proposed by Marsden et al. [Opt Lett 18 (1993), 1083–1085]. © 2002 Wiley Periodicals, Inc.
Using the modified 2nd order incomplete Cholesky decomposition as the conjugate gradient preconditioning
Authors: Kaporin I. E.
Published: October 2002

In this paper, the ‘second‐order’ incomplete triangular factorization (Kaporin, 1998) is considered as a preconditioner for the CG method. Some refinements of the original algorithm are proposed and investigated, which give rise to a more efficient modified incomplete Cholesky 2nd‐order (MIC2) type preconditionings. Numerical results are given for a set of real‐life large‐scale SPD linear systems arising in the finite element modelling of linear elasticity problems which clearly indicate the superiority of the MIC2 preconditionings. Copyright © 2002 John Wiley & Sons, Ltd.
A finite element method using singular functions for the Poisson equation: crack singularities
Authors: Cai Zhiqiang , Kim Seokchan , Woo Gyungsoo
Published: October 2002

In Cai and Kim (SIAM J. Numer. Anal. 2001; 39: 286), we developed and analysed a new accurate finite element method using singular functions for the Poisson equation on a two‐dimensional polygonal domain with re‐entrant corners. This method first computes the regular part of the solution, then stress intensity factors, and finally the solution itself. This note extends this method to the Poisson equation on a domain with cracks and considers a higher‐order method when f∈ H1(Ω). Copyright © 2002 John Wiley & Sons, Ltd.
Refined second order semi‐analytical design sensitivities
Authors: de Boer H. , van Keulen F. , Vervenne K.
Published: October 2002

Accurate and efficient calculation of second order design sensitivities in a finite element context is often difficult. The semi‐analytical (SA) method is efficient and easy to implement but has accuracy problems even for first order shape design sensitivities. To overcome accuracy problems a refined semi‐analytical (RSA) method has been developed for first order sensitivities. The present paper investigates the application of the RSA method to second order design sensitivities. It is found that second order RSA sensitivities are significantly more accurate than their SA counterparts. Copyright © 2002 John Wiley & Sons, Ltd.
Large‐deformation and friction analysis of non‐linear elastic cable networks by second‐order cone programming
Authors: Kanno Y. , Ohsaki M. , Ito J.
Published: October 2002

A new formulation is presented for equilibrium shape analysis of cable networks considering geometrical and material non‐linearities. Friction between cables and joint devices is also considered. The second‐order cone programming (SOCP) problem which has the same solution as that of minimization of total potential energy is solved to obtain the equilibrium configuration. The optimality conditions are derived to verify that the solution satisfies equilibrium conditions and friction laws. Since no assumption on stress state is needed in the proposed method, no process of trial and error is involved. No effort is required to develop any analysis software because SOCP can be solved by using the well‐developed software based on the interior‐point method. Copyright © 2002 John Wiley & Sons, Ltd.
Solution of non‐linear boundary integral equations in complex geometries with auxiliary integral subtraction
Authors: Mammoli Andrea A.
Published: October 2002

The boundary integral equation that results from the application of the reciprocity theorem to non‐linear or non‐homogeneous differential equations generally contains a domain integral. While methods exist for the meshless evaluation of these integrals, mesh‐based domain integration is generally more accurate and can be performed more quickly with the application of fast multipole methods. However, polygonalization of complex multiply‐connected geometries can become a costly task, especially in three‐dimensional analyses. In this paper, a method that allows a mesh‐based integration in complex domains, while retaining a simple mesh structure, is described. Although the technique is intended for the numerical solution of more complex differential equations, such as the Navier–Stokes equations, for simplicity the method is applied to the solution of a Poisson equation, in domains of varying complexity. It is shown that the error introduced by the auxiliary domain subtraction method is comparable to the discretization error, while the complexity of the mesh is significantly reduced. The behaviour of the error in the boundary solution observed with the application of the new method is analogous to the behaviour observed with conventional cell‐based domain integration. Copyright © 2002 John Wiley & Sons, Ltd.
How reliable are immunological tools for the detection of ancient proteins in fossil bones?
Authors: Brandt Elisabeth , Wiechmann Ingrid , Grupe Gisela
Published: October 2002

100 Pre‐Contact human skeletons from six different excavation sites on the Peruvian coast, which showed an excellent state of preservation both on the macro‐ and the microscopic level, have been investigated for the preservation of three plasma proteins (α2‐HS‐glycoprotein, albumin and α1‐antitrypsin) by enzyme‐linked immunosorbent assay. A subsample of 40 skeletons out of this skeletal series had been analysed for the state of preservation of polymorphic plasma proteins by electrophoretic methods (Brandt et al., 2000), revealing extensive alterations of the target proteins by diagenesis. The question remained, therefore, as to the reliability of common immunological tools for the unambiguous detection and quantification of non‐collagenous proteins in archaeological bone. In this study, we succeeded in the immunological detection of three target proteins in the skeletal remains. However, a variety of non‐specific reactions were also observed with bone extracts from non‐human mammals, some collagen types, and also bacterial cells. This wide range of cross‐reactions with antigens not normally tested in the course of the production of commercially available antibodies adds a cautionary note to immunological approaches towards the study of ancient proteins. Copyright © 2002 John Wiley & Sons, Ltd.
A test of two methods of radiographically deriving long bone cross‐sectional properties compared to direct sectioning of the diaphysis
Authors: Stock Jay T.
Published: October 2002

Numerous studies have made use of cross‐sectional geometry to describe the distribution of cortical bone in long bone diaphyses. Several methods can be used to measure or estimate cross‐sectional contours. Direct sectioning (DSM) of the diaphysis is not appropriate in most curatorial contexts, and is commonly substituted with methods based upon bi‐planar radiography: a latex cast method (LCM) or an eccentric elliptical method (EEM). Previous studies have demonstrated that the EEM provides accurate estimates of area measurements, while providing less accurate estimates of second moments of area (Biknevicius & Ruff, 1992; Runestad et al., 1993; Lazenby, 1997). The LCM has been commonly employed, as a way to estimate section contours more accurately, yet the validity of this method has not been adequately documented. This study measures the agreement of these methods against DSM of long bone diaphyses using 21 sections of canine tibiae derived from a study of total hip arthroplasty. The accuracy and agreement of these methods is evaluated using reduced major axis regression, paired sample t‐tests and tests for agreement (Bland & Altman, 1986). The results illustrate that the LCM provides a reasonable estimate of cross‐sectional dimensions, producing cross‐sectional properties that are on average within 5% of properties derived from the DSM. The EEM is found to provide adequate estimates of true cross‐sectional areas, but poor estimates of second moments of area. The use of the LCM is supported for all cross‐sectional properties, but the EEM is only accurate in total area, cortical area and percent cortical area estimates. Copyright © 2002 John Wiley & Sons, Ltd.