bluuebunny/crossref_metadata_2025 huggingface dataset:
Total duration of negative surplus for the compound Poisson process that is perturbed by diffusion
Authors: Zhang Chunsheng , Wu Rong
Published: April 2003

In this paper, we consider the compound Poisson process that is perturbed by diffusion (CPD). We derive formulae for the Laplace transform, expectation and variance of total duration of negative surplus for the CPD and also present some examples of the CPD with an exponential individual claim amount distribution and a mixture exponential individual claim amount distribution.
Poisson traffic flow in a general feedback queue
Authors: Peköz Erol A. , Joglekar Nitindra
Published: April 2003

Consider a ·/G/k finite-buffer queue with a stationary ergodic arrival process and delayed customer feedback, where customers after service may repeatedly return to the back of the queue after an independent general feedback delay whose distribution has a continuous density function. We use coupling methods to show that, under some mild conditions, the feedback flow of customers returning to the back of the queue converges to a Poisson process as the feedback delay distribution is scaled up. This allows for easy waiting-time approximations in the setting of Poisson arrivals, and also gives a new coupling proof of a classic highway traffic result of Breiman (1963). We also consider the case of nonindependent feedback delays.
The house-selling problem with reward rate criterion
Authors: Mazalov Vladimir V. , Saario Vesa
Published: April 2003

We consider a variant of the house-selling problem in which the seller has n objects for sale and the buyers come sequentially one by one. The objective of this paper is to find the seller's optimal strategy for choosing his selling price so as to maximize the average reward per selling attempt until the nth house is sold.
From matchbox to bottle: a storage problem
Authors: Baringhaus Ludwig , Grübel Rudolf
Published: April 2003

We generalize Banach's matchbox problem: demands of random size are made on one of two containers, both initially with content t, where the container is selected at random in the successive steps. Let Zt be the content of the other container at the moment when the selected container is found to be insufficient. We obtain the asymptotic distribution of Zt as t → ∞ under quite general conditions. The case of exponentially distributed demands is considered in more detail.
Availability of periodically inspected systems subject to Markovian degradation
Authors: Kiessler Peter C. , Klutke Georgia-Ann , Yang Yoonjung
Published: April 2003

This paper studies inspected systems with non-self-announcing failures where the rate of deterioration is governed by a Markov chain. We compute the lifetime distribution and availability when the system is inspected according to a periodic inspection policy. In doing so, we expose the role of certain transient distributions of the environment.
Compound random mappings
Authors: Hansen Jennie C. , Jaworski Jerzy
Published: April 2003

In this paper, we introduce a compound random mapping model which can be viewed as a generalization of the basic random mapping model considered by Ross and by Jaworski. We investigate a particular example, the Poisson compound random mapping, and compare results for this model with results known for the well-studied uniform random mapping model. We show that, although the structure of the components of the random digraph associated with a Poisson compound mapping differs from the structure of the components of the random digraph associated with the uniform model, the limiting distribution of the normalized order statistics for the sizes of the components is the same as in the uniform case, i.e. the limiting distribution is the Poisson-Dirichlet (½) distribution on the simplex {{xi} : ∑ xi ≤ 1, xi ≥ xi+1 ≥ 0 for every i ≥ 1}.
Periodic Ornstein-Uhlenbeck processes driven by Lévy processes
Authors: Pedersen Jan
Published: April 2003

In this paper, the class of periodic Ornstein-Uhlenbeck processes is defined. It is shown that periodic Ornstein-Uhlenbeck processes are stationary Markov random fields and the class of stationary distributions is characterized. In particular, any self-decomposable distribution is the stationary distribution of some periodic Ornstein-Uhlenbeck process. As examples, gamma periodic Ornstein-Uhlenbeck processes and Gaussian periodic Ornstein-Uhlenbeck processes are considered.
The age of a Galton-Watson population with a geometric offspring distribution
Authors: Klebaner F. C. , Sagitov S.
Published: April 2003

Motivated by the question of the age in a branching population we try to recreate the past by looking back from the currently observed population size. We define a new backward Galton-Watson process and study the case of the geometric offspring distribution with parameter p in detail. The backward process is then the Galton-Watson process with immigration, again with a geometric offspring distribution but with parameter 1-p, and it is also the dual to the original Galton-Watson process. We give the asymptotic distribution of the age when the initial population size is large in supercritical and critical cases. To this end, we give new asymptotic results on the Galton-Watson immigration processes stopped at zero.
Strong ergodicity for Markov processes by coupling methods
Authors: Mao Yong-Hua
Published: April 2003

In this paper, we apply coupling methods to study strong ergodicity for Markov processes, and sufficient conditions are presented in terms of the expectations of coupling times. In particular, explicit criteria are obtained for one-dimensional diffusions and birth-death processes to be strongly ergodic. As a by-product, strong ergodicity implies that the essential spectra of the generators for these processes are empty.
Transient analytical solution of M/D/1/N queues
Authors: Garcia Jean-Marie , Brun Olivier , Gauchard David
Published: April 2003

An analytical expression of the time-dependent probability distribution of M/D/1/N queues initialised in an arbitrary deterministic state is derived. We also obtain a simple analytical expression of the differential equation governing the transient average traffic which only involves probabilities of boundary states. As a by-product, a closed form solution of the departure rate from the system is also determined.
Conditional job-observer property for multitype closed queueing networks
Authors: Daduna Hans , Szekli Ryszard
Published: April 2003

For functionals of multitype closed queueing networks, a conditional job-observer property is shown which provides more insight into the classical job-observer property. Applications and examples are given, including the classical job-observer property for the number of customers in a network, a representation of cycle time distributions and a basic formula for sojourn times.
On modes of long-range dependence
Authors: Heyde C. C.
Published: April 2003

This paper aims at enhancing the understanding of long-range dependence (LRD) by focusing on mechanisms for generating this dependence, namely persistence of signs and/or persistence of magnitudes beyond what can be expected under weak dependence. These concepts are illustrated through a discussion of fractional Brownian noise of index H ∈ (0,1) and it is shown that LRD in signs holds if and only if ½ < H < 1 and LRD in magnitudes if and only if ¾ ≤ H < 1. An application to discrimination between two risky asset finance models, the FATGBM model of Heyde and the multifractal model of Mandelbrot, is given to illustrate the use of the ideas.
Evidence of a novel transduction pathway mediating detection of polyamines by the zebrafish olfactory system
Authors: Michel W. C. , Sanderson M. J. , Olson J. K. , Lipschitz D. L.
Published: April 2003

To better understand the full extent of the odorant detection capabilities of fish, we investigated the olfactory sensitivity of zebrafish to a monoamine and several polyamines using electrophysiological and activity-dependent labeling techniques. Electro-olfactogram (EOG) recording methods established the relative stimulatory effectiveness of these odorants as: spermine >>spermidine ≈ agmatine > glutamine > putrescine ≥ cadaverine ≥histamine > artificial freshwater. The detection threshold for the potent polyamines was approximately 1 μmol l–1. Cross-adaptation experiments suggested that multiple receptors are involved in polyamine detection. Three observations indicated that polyamine signaling may involve a transduction cascade distinct from those used by either amino acids or bile salts. Like bile salts and the adenylate cyclase activator forskolin, but unlike amino acid odorants, polyamines failed to stimulate activity-dependent labeling of olfactory sensory neurons with the cation channel permeant probe agmatine, suggesting a signaling pathway different from that used by amino acid stimuli. Also supporting distinct amino acid and polyamine signaling pathways is the finding that altering phospholipase C activity with the inhibitor U-73122 significantly reduced amino acid-evoked responses, but had little effect on polyamine- (or bile salt-) evoked responses. Altering cyclic nucleotide-mediated signaling by adenylate cyclase activation with forskolin,which significantly reduced responses to bile salts, failed to attenuate polyamine responses, suggesting that polyamines and bile salts do not share a common transduction cascade. Collectively, these findings suggest that polyamines are a new class of olfactory stimuli transduced by a receptor-mediated, second messenger signaling pathway that is distinct from those used by amino acids or bile salts.
Liposome Immobilization on Polymer Gel Particles by in situ Formation of Covalent Linkages
Authors: Khaleque Md Abdul , Okumura Yukihisa , Yabushita Satoshi , Mitani Michiharu
Published: April 2003

In situ formation of disulfide linkages between liposomes and Sephacryl gel particles both of that were bearing mercapto moieties was demonstrated. The reaction led to immobilization of the liposomes on the gel. The immobilized liposomes could be detached by reductive treatment of the liposome-gel conjugate, and the resulting gel was still capable of further immobilizing liposomes.
Total Synthesis of (±)-Aiphanol, a Novel Cyclooxygenase-inhibitory Stilbenolignan
Authors: Kuboki Atsuhito , Yamamoto Toru , Ohira Susumu
Published: April 2003

(±)-Aiphanol has been stereoselectively synthesized through IBX-mediated o-quinone formation, and through [4+2] cycloaddition of the o-quinone and cinnamyl alcohol unit.
Novel Monocation, Dication, and Dianion of a Cage Molecule, Trithienylmethanophane
Authors: Kurata Hiroyuki , Haruki Kenji , Nakaminami Hiromichi , Kawase Takeshi , Oda Masaji
Published: April 2003

The McMurry coupling of tris(5-formyl-2-thienyl)methane afforded an unsubstituted, etheno-bridged trithienylmethanophane which was in turn transformed to novel cage-molecular monocation, dication, and dianion of substantial stability. The latter two species are the first examples of fully conjugated ionic cyclophane cage molecule.
Xerox's Approach to Sustainability
Authors: Maslennikova Irina , Foley David
Published: April 2003

Xerox's environmental strategic goal is to become a waste-free company. This ideal permeates the life cycle of Xerox products: waste-free products from waste-free factories for waste-free offices. Xerox has witnessed numerous benefits from implementing this strategy; by using design-for-the-environment principles, it has redesigned products and packaging to support product recovery and to reduce resource and energy consumption. Implementation of an end-of-life equipment takeback and reprocessing program led to savings of over $80 million in Europe in 1997, in addition to turning a potential disposal cost into a revenue stream. Through its environmental leadership program, Xerox has evolved a win-win-win scenario: improvements in environmental performance (win), customer satisfaction (win), and improved company performance (win).
Sustainability and the Firm
Authors: Reinhardt Forest
Published: April 2003

Macroeconomic definitions of sustainability focus on the need to maintain aggregate stocks of natural and manufactured capital constant over time, so that future generations have consumption possibilities similar to those of the current generation. Similar tests can be applied at the firm level. To be sustainable, a company must maintain on its balance sheet an undiminished level of total net assets, measured at their social costs. It must also pass a similar test when assets are valued at prevailing private costs. To make realistic assessments of a country's or firm's sustainability, therefore, one needs to consider its overall economic performance as well as its environmental performance. By this definition, sustainability is intimately linked to the fundamental preoccupations of business managers: productivity, investment, and profit.
Separating Inventory Flows in the Materials Management Department of Hancock Medical Center
Authors: Jayaraman Vaidyanathan , Burnett Cindy , Frank Derek
Published: April 2003

The materials management department of Hancock Medical Center was responsible for distribution of medical supplies to four major segments of the medical center, tracking inventory of items, accepting vendor delivery of items, and providing daily mail service for the entire medical center. The department was fraught with problems—deliveries were not made to schedule, departmental staffs were unable to keep accurate information on inventory, and the role of staff was not clearly defined. We made some recommendations that helped the department in streamlining their operations. The recommendations also helped to improve the overall logistics system and were useful for strategic planning and refinement of the materials management department of the Hancock Medical Center.
The Québec Ministry of Natural Resources Uses Linear Programming to Understand the Wood-Fiber Market
Authors: Gautier Antoine , Lamond Bernard F. , Paré Daniel , Rouleau François
Published: April 2003

In spring 1996, Québec's Ministry of Natural Resources began using a descriptive mathematical programming model to support various negotiations in the wood-fiber markets. The model, which uses linear programming to solve an economic-equilibrium program, allows the representative of the ministry to come to industry roundtables with accurate scenario analyses for the wood-fiber market. The tool we developed and implemented uses the large amounts of data available to government agencies to foresee and explain the general economic trends facing both lumber and paper producers. During its development, our team of operations-research experts, economists, engineers, and civil servants developed an unprecedented understanding of the wood-fiber market. The ministry incorporated these insights in subsequent government policy aimed at improving sawmill yield and stabilizing market behavior.
Holt‐Oram syndrome: Is there a “face”?
Authors: Allanson Judith E. , Newbury‐Ecob Ruth A.
Published: April 2003

Holt‐Oram syndrome, first described in 1960, is one of many heart‐hand syndromes. Upper limb involvement, predominantly radial, is universal, bilateral and asymmetrical, with variable severity. Cardiac defects occur in 95% of familial cases. Inheritance is autosomal dominant with 100% penetrance and no evidence of reduced fitness. Mutations in TBX5 have been reported in Holt‐Oram syndrome. This study was conducted to establish whether a particular facial appearance is associated with Holt‐Oram syndrome, one which might facilitate early diagnosis and aid differentiation from other heart‐hand syndromes. Twenty‐five individuals were evaluated, age 11 months to 70 years. A complete dysmorphological examination was carried out, serial photographs were reviewed, and a series of anthropometric craniofacial measurements was obtained. Subjectively, the face is square with a broad lower jaw and parietal bossing. The forehead is prominent and tall. There is narrowing at the temples. Eyes seem close‐set. The nose appears relatively long, with a wide base, and short columella. With age the face becomes longer and more oval. Our anthropometric approach confirms certain clinical impressions. However, there is no objective evidence for increased face or nose height, two of the most striking features of the “gestalt.” Nasal height is, in fact, reduced at all ages. There does not appear to be a syndrome‐specific pattern profile to facilitate the discrimination of this condition from other heart‐hand syndromes. © 2003 Wiley‐Liss, Inc.
Tetrasomy 8p: Discordance of amniotic fluid and blood karyotypes
Authors: López‐Pajares I. , Delicado A. , Lapunzina P. , Mori M.A. , de Torres M.L. , Aso S. , Garcia Sanchez P.
Published: April 2003

We describe a girl with congenital heart defect (ventricular septal defect), facial, ear and bone anomalies, agenesis of corpus callosum and conventional cytogenetic studies showing tetrasomy 8p. The identity of the isochromosome was confirmed by fluorescent in situ hybridization (FISH) using painting, subtelomeric and alpha satellite probes for chromosome 8. The extra isochromosome was observed in 100% of cultured peripheral lymphocytes (47,XX,+i(8)(p10)), but normal chromosomes were recorded in cultured amniotic fluid. Microsatellites analysis of the patient's DNA with two markers mapping 8p showed three different peaks, and two markers mapping 8q showed two peaks. To the best of our knowledge, this patient represents the twelfth reported case of tetrasomy 8p. In addition, our report is the first case with a pure tetrasomy 8p in blood, (the other published cases are mosaic 8p), and the second case with a discordance of amniotic fluid and blood karyotypes [Robinow et al., 1989: Am J Med Genet 32:320–324]. © 2003 Wiley‐Liss, Inc.
Late‐Onset visceral presentation with cardiomyopathy and without neurological symptoms of adult Sanfilippo A syndrome
Authors: Van Hove Johan L.K. , Wevers Ron A. , Van Cleemput Johan , Moerman Philippe , Sciot Raf , Matthijs Gert , Schollen Els , de Jong Jan G.N. , Carey William F. , Muller Viv , Nicholls Cath , Perkins Kelly , Hopwood John J.
Published: April 2003

Sanfilippo A syndrome, mucopolysaccharidosis type IIIA, is caused by a deficiency of heparan sulphamidase activity, and usually presents in childhood with neurodegeneration leading to death in teenage years. Visceral symptoms are limited to coarsening and diarrhea. We now describe an adult patient who presented with cardiomyopathy. At age 45 years she had hypertension, and the next year she developed a progressively worsening cardiomyopathy with prominent apical hypertrophy and atrial fibrillation. At age 53, she had severe concentric hypertrophic nonobstructive cardiomyopathy in both ventricles. There was no coarsening of features. Neurologic function, skeleton, cornea, liver, and spleen were normal. Percutaneous endomyocardial biopsy showed ballooned cardiomyocytes with storage vacuoles, containing acid mucopolysaccharides. Leucocytes, uterus, and brain biopsy did not show this storage material. There was a slight increase in total urine mucopolysaccharides, with an increased proportion of heparan sulfates. Heparan sulphamidase activity was deficient in leukocytes and heparan sulphamidase protein and activity were reduced in cultured fibroblasts. No mutations were identified after sequencing of the heparan sulphamidase gene at the cDNA and the genomic level. This new clinical presentation expands the clinical spectrum of Sanfilippo A syndrome to include a primary visceral presentation of cardiomyopathy without neurologic symptoms in the adult. The late onset may be related to the residual heparan sulphamidase activity. The genetic basis of this new variant is still unclear. Physicians evaluating adults must remain aware of possible new adult presentations of storage conditions. © 2003 Wiley‐Liss, Inc.
Haplotypes of α‐globin gene regulatory element in two Brazilian native populations
Authors: Ribeiro Daniela M. , Figueiredo Maria S. , Costa Fernando F. , Sonati Maria F.
Published: April 2003

The α‐major regulatory element (α‐MRE), located 40 Kb far upstream of the α‐globin gene cluster on chromosome 16, is involved in the regulation of human α‐globin genes expression. The activity of this element is restricted to a 350‐bp fragment in which several nuclear protein binding sites have been identified. This element is genetically polymorphic and different haplotypes, named A–F, have been determined in seven populations of Europe, Africa, Asia, and Oceania. We describe here the α‐MRE haplotypes found in native Indians from two nonmiscegenated tribes of the north region of Brazil, in Amazonia, the Parakanã and the Xikrin. The A haplotype was predominant in both (70% and 87%, respectively), followed by the B haplotype (30% and 13%, respectively). The haplotype frequency distribution among the Parakanã was similar to that reported for Indonesians and Southeast Asian populations, while the distribution among the Xikrin showed higher similarity to that observed in Indonesians. These results corroborate the existence of genetic affinities between Brazilian Indians and Southeast Asian and Oceanic populations. This was the first investigative work on the α‐MRE polymorphism in South American native populations in general or Brazilian native populations in particular. Am J Phys Anthropol 121:000–000, 2003. © 2003 Wiley‐Liss, Inc.
Syndiotactic polymerization of styrene catalyzed by alkenyl‐substituted cyclopentadienyltitanium trichlorides
Authors: Qian Xianmiao , Huang Jiling , Qian Yanlong , Wang Chen
Published: April 2003

CH2CHCH2CpTiCl3 (1), CH2CHCH2CH2CpTiCl3 (2) and CH3CH2CH3CpTiCl3 (3) have been synthesized and characterized. The influence of the alkenyl substituent groups on the catalyst activities in the syndiotactic polymerization of styrene was investigated. The catalyst activities decreased in the order CH2CHCH2CH2CpTiCl3 > CH3CH2CH2CH2CpTiCl3 > CH3CH2CH2CpTiCl3 > CH2CHCH2CpTiCl3 (CpC5H4). By using complex 1, the dependence of the activity on the concentration of methylaluminoxane, triisobutylaluminum and diisobutylaluminum hydride was investigated. Copyright © 2003 John Wiley & Sons, Ltd.
Transients from a mixture of [(R(O)Sn)2C(CH3)2]2 and (RCl2Sn)2C(CH3)2 [R = (SiMe3)2CH]: an identification in situ by 1D 119Sn and 2D 1H119Sn HMQC NMR spectroscopy and electrospray mass spectrometry
Authors: Biesemans Monique , Duthie Andrew , Jurkschat Klaus , Verbruggen Ingrid , Willem Rudolph , Zobel Bernhard
Published: April 2003

The reaction of the 2,2‐bis(organodichlorostannyl)propane [(Me3Si)2CH(Cl2)Sn]2CMe2 (A) with the corresponding organotin oxide {[(Me3Si)2CH(O)Sn]2CMe2}2 (B) does not provide the corresponding normally expected tetraorganodistannoxane {[(Me3Si)2CH(Cl)SnCMe2Sn(Cl)CH(SiMe3)2]O}n but a complex reaction mixture. One major product, namely the 2,4,6,8‐tetraorgano‐2,6‐dichloro‐1,5,9‐trioxa‐2,4,6,8‐tetrastannabicyclo[3.3.1]nonane derivative [(Me3Si)2CHSnCMe2Sn(Cl)CH(SiMe3)2]2O3 (C) was identified in situ by 2D 1H119Sn and 1H13C heteronuclear multiple quantum coherence and heteronuclear multiple bond correlation NMR spectroscopy as well as electrospray mass spectrometry. Compound C is proposed to be in equilibrium with an ionic species C′, the cation of which has an adamantane‐type structure. Copyright © 2003 John Wiley & Sons, Ltd.
Properties of polyacrylate soap‐free hydrosol with zirconium chelate
Authors: Huang Zhi Hong , Xie Zhi Ming , Li Zhuo Mei
Published: April 2003

The effect of the amount of triethanolamine zirconium isopropyloxide chelate in acrylate terpolymer soap‐free hydrosol on the properties of hydrosol and its film was studied. The addition of the chelate increased the hydrosol viscosity to 20 mPas and improved the hydrosol film water resistance; the water uptake was reduced to 0.6%, and the hydrosol still retained good resolubility. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2858–2860, 2003
Kinetics of amide formation on 1,4‐butanediol dimethacrylate crosslinked polystyrene resin: A comparison with PS‐DVB resin
Authors: Roice M. , Pillai V. N. Rajasekharan
Published: April 2003

An efficient crosslinked polymer support was synthesized by introducing 1,4‐butanediol dimethacrylate crosslinker to a polystyrene network using aqueous suspension polymerization technique. The support was functionalized with aminomethyl groups using chloromethyl phthalimide. The kinetics of amide bond formation on 1,4‐butanediol dimethacrylate crosslinked polystyrene (PS‐BDODMA) polymer were carried out using the attachment of Rink amide linker as a model reaction. The efficiency of the support was tested and compared with Merrifield resin by following different steps involved in the synthesis of a 14‐residue model peptide, Lys‐Ile‐Asn‐Thr‐Asn‐Ala‐Ser‐Trp‐His‐Ala‐Asn‐Arg‐Thr‐Ala‐NH2, under the same synthetic conditions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2897–2903, 2003
Synthesis of new chelating ion exchange resin with hydroxamic and amidoxime groups and study of its metal binding property
Authors: Neagu Violeta , Bunia I. , Plesca I. , Popa M.
Published: April 2003

The synthesis of a new chelating ion exchanger with hydroxamic and amidoxime groups was performed by an aminolysis reaction of an ethylacrylate/acrylonitrile/divinylbenzene copolymer with hydroxylamine in the presence of sodium ethoxylate. We studied the retention property of the new resin for Pb(II), Cd(II), Cu(II), Ni(II), Zn(II), Mn(II), and Fe(III) metal cations from aqueous solutions. The retention capacity depends on the contact time, the pH of the solution, and the types of counterions of the metal cations. Competitive adsorptions of Pb(NO3)2 + Fe2(SO4)3, Pb(NO3)2 + MnSO4, Pb(NO3)2 + Cd(NO3)2, and Pb(NO3)2 + CuCl2 on the new chelating ion exchanger were performed. The results showed that the resin preferentially retained the Pb(II) ions from the binary aqueous mixtures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2956–2962, 2003
Dual lower critical solution temperature polymer networks based on block, laminate, and interpenetrating network structures composed of N‐alkylacrylamides and N,N‐dialkylaminoethyl methacrylates
Authors: Stoltz Michael J. , Brazel Christopher S.
Published: April 2003

Novel materials that display two lower critical solution temperatures (LCSTs) were developed by forming block copolymers, laminate structures, and interpenetrating networks of crosslinked polymer systems that displayed temperature sensitivity independently. A number of LCST polymers and copolymers were investigated, including those based on N‐isopropylacrylamide, N,N‐diethylacrylamide, N,N‐diethylaminoethyl methacrylate, and N,N‐dimethylaminoethyl methacrylate. The polymer structure was found to profoundly influence the thermal sensitivity, as polymer formulation techniques led to materials with varying degrees of temperature sensitivity. Random and block copolymerization, along with interpenetrating networks and laminate systems, were studied, with only the structures having the greatest physical separation between pendent chains of different types having the ability to separate temperature transitions. Experiments were conducted to characterize the equilibrium swelling behavior and thermal transitions in the polymer systems. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2974–2981, 2003
Interobserver agreement in ultrasonography of the finger and toe joints in rheumatoid arthritis
Authors: Szkudlarek Marcin , Court‐Payen Michel , Jacobsen Søren , Klarlund Mette , Thomsen Henrik S. , Østergaard Mikkel
Published: April 2003

Objective

To evaluate the interobserver agreement of ultrasonographic assessment of finger and toe joints in patients with rheumatoid arthritis (RA) by 2 investigators with different medical backgrounds.

Methods

Ultrasonography and clinical examination were performed on 150 small joints of 30 patients with active RA. A General Electric LOGIQ 500 ultrasound unit with a 7–13‐MHz linear array transducer was used. In each patient, 5 preselected small joints (second and third metacarpophalangeal, second proximal interphalangeal, first and second metatarsophalangeal) were examined independently on the same day by 2 ultrasound investigators (an experienced musculoskeletal radiologist and a rheumatologist with limited ultrasound training). Joint effusion, synovial thickening, bone erosions, and power Doppler signal were evaluated in accordance with an introduced 4‐grade semiquantitative scoring system, on which the investigators had reached consensus prior to the study.

Results

Exact agreement between the 2 observers was seen in 91% of the examinations with regard to bone erosions, in 86% with regard to synovitis, in 79% with regard to joint effusions, and in 87% with regard to power Doppler signal assessments. Corresponding intraclass correlation coefficient values were 0.78, 0.81, 0.61, and 0.72, respectively, while unweighted kappa values were 0.68, 0.63, 0.48, and 0.55, respectively. Ultrasonography showed signs of inflammation in 94 joints, while clinical assessment revealed tenderness and/or swelling in 64 joints.

Conclusion

An experienced radiologist and a rheumatologist with limited ultrasound training achieved high interobserver agreement rates for the identification of synovitis and bone erosions, using an introduced semiquantitative scoring system for ultrasonography of finger and toe joints in RA. Signs of inflammation were more frequently detected with ultrasound than with clinical examination. Ultrasonography may improve the assessment of RA patients by radiologists and rheumatologists.
Efficacy of etanercept for the treatment of juvenile idiopathic arthritis according to the onset type
Authors: Quartier Pierre , Taupin Pierre , Bourdeaut Franck , Lemelle Irène , Pillet Pascal , Bost Michel , Sibilia Jean , Koné‐Paut Isabelle , Gandon‐Laloum Sylvie , LeBideau Marc , Bader‐Meunier Brigitte , Mouy Richard , Debré Marianne , Landais Paul , Prieur Anne‐Marie
Published: April 2003

Objective

To assess the efficacy of etanercept in patients with juvenile idiopathic arthritis (JIA), and to assess the tolerance of these patients to etanercept.

Methods

All JIA patients with active chronic polyarthritis, who were first treated with etanercept between November 1999 and June 2001 in 18 French centers because of poor response or intolerance to methotrexate, were included in this open‐label, prospective, multicenter study. A standardized questionnaire was sent to the treating physicians. We assessed the validated international core‐set score for JIA activity every 3 months and performed an intent‐to‐treat analysis. We also compared the risk of treatment failure in patients defined as having systemic‐onset, oligoarticular‐onset, or polyarticular‐onset JIA.

Results

Sixty‐one patients were enrolled and were followed up for a median of 13 months. Treatment had to be stopped in 1 patient who became pregnant and in 12 patients due to severe side effects, including neurologic or psychiatric disorders, retrobulbar optic neuropathy, major weight gain, severe infection, cutaneous vasculitis with systemic symptoms, hemorrhagic diarrhea, uveitis flare, and pancytopenia. All of these side effects disappeared after discontinuation of etanercept. Crohn's disease was subsequently diagnosed in 1 child. Scores improved by ≥30% in 73% of patients after 3 months, but this proportion decreased to 39% after 12 months. The response rate was significantly lower in patients with systemic‐onset JIA than in those with oligoarticular‐ or polyarticular‐onset JIA.

Conclusion

Treatment of JIA with etanercept may be associated with a wide spectrum of severe side effects. Although most patients initially respond to etanercept, this initial response is not always followed by sustained improvement over longer periods of time. In addition, the higher rate of treatment failure in the group with systemic‐onset JIA indicates that these patients in particular may require alternative treatments.
Declining use of orthopedic surgery in patients with rheumatoid arthritis? Results of a long‐term, population‐based assessment
Authors: Da Silva Eleonora , Doran Michele F. , Crowson Cynthia S. , O'Fallon W. Michael , Matteson Eric L.
Published: April 2003

Objective

To describe the use of orthopedic surgery, including joint replacement surgery, in a well‐defined, population‐based cohort of patients with rheumatoid arthritis (RA) and to identify characteristics that predict such use.

Methods

A retrospective medical record review was performed of cases of RA incident in Rochester, Minnesota, during the years 1955–1995. All joint surgeries were recorded.

Results

Of the total 609 RA incident cases, 242 patients underwent 1 or more (maximum of 20/patient) surgical procedures involving joints during their followup. Overall, this RA cohort had 7.4 surgeries per 100 person‐years of followup; the cumulative incidence for joint surgery for RA‐related joint disease at 30 years was 33.7% ± SEM 3.8%. The risk of having a disease‐related joint surgery for RA is increased in patients who are women, younger, positive for rheumatoid factor, and have rheumatoid nodules. When adjusted for duration of followup, patients with RA diagnosed after 1985 were significantly less likely to have undergone joint surgery for RA (P< 0.001). Survival of patients who underwent total joint arthroplasty was similar to those who did not.

Conclusion

Reconstructive surgeries are common in RA, although patients diagnosed after 1985 are less likely to require joint surgery. These findings may reflect trends in medical disease management and have importance for health care resource utilization planning.
A rapid and sensitive 384‐well microtitre format chemiluminescent enzyme immunoassay for 19‐nortestosterone
Authors: Roda Aldo , Manetta Anna Chiara , Portanti Ottavio , Mirasoli Mara , Guardigli Massimo , Pasini Patrizia , Lelli Rossella
Published: April 2003

We developed a competitive chemiluminescent (CL) enzyme immunoassay for rapid, sensitive analysis of 19‐nortestosterone (19‐NT) in bovine urine. Anti‐19‐NT polyclonal antibodies were raised in rabbits using a 19‐NT‐hemisuccinate derivative conjugated with ovalbumin; the derivative was also conjugated with horseradish peroxidase (HRP) as a label. Antibodies were immobilized on 384‐well black polystyrene microtitre plates and HRP‐labelled 19‐NT activity was measured using an efficient chemiluminescent substrate (SuperSignal® ELISA Femto) after 3 min incubation. Emitted light was recorded using a conventional, photomultiplier‐tube‐based microtitre plate reader or a sensitive back‐illuminated, cooled CCD camera. The developed method fulfils all the requirements of precision (intra‐ and inter‐assay CV < 10%) and accuracy (mean recovery 94–112%), with a detection limit of 0.03 ppb (1.1 × 10−9 mol/L) in a urine matrix. Chemiluminescence enhances detectability of the HRP‐labelled tracer (thus lowering the limit of detection with respect to colorimetry) and reduces analysis time. The 384‐well microtitre plate cuts the sample/reagent volume (20 µL), a five‐fold reduction with respect to the conventional 96‐well microtitre plate. The developed method is suitable for high‐throughput screening of 19‐NT in urine samples, with reduced costs as compared with conventional colorimetric enzyme immunoassays. Copyright © 2003 John Wiley & Sons, Ltd.
Afferent and efferent connections of the cerebellum of the chondrostean Acipenser baeri: A carbocyanine dye (DiI) tracing study
Authors: Huesa Gema , Anadón Ramón , Yáñez Julián
Published: April 2003

The afferent and efferent connections of the cerebellum of the primitive bony fish Acipenser baeri were studied in fixed brains with a fluorescent lipophylic carbocyanine (DiI). The three regions of the cerebellum (the auricles, valvula, and corpus) showed similar afferents, mostly originated from extensive precerebellar populations of the midbrain tegmentum and from the inferior olive. A pretectal nucleus was also labeled after DiI application to the three regions of the cerebellum. However, DiI application to the pretectal region revealed that the pretectocerebellar projection mainly targeted to the caudal region of the corpus cerebelli. Some precerebellar cells were observed in the torus semicircularis, isthmic central gray, and rhombencephalic reticular formation. Primary fibers of the anterior lateral line nerve and neurons of the octavolateral area also project to the auricle. After DiI application to the auricles, most ascending efferents coursed to the region of the nucleus of the medial longitudinal fascicle and thalamus, mostly contralaterally. Ipsilateral descending fibers were also labeled in the medullary octavolateral area. Application of DiI to the nucleus of the medial longitudinal fascicle revealed three clusters of cerebellar projection neurons located in the granular layers of the auricles, valvula, and corpus cerebelli, mostly contralateral to the application site. These cerebellar projection neurons did not exhibit a number of characteristics of teleost eurydendroid cells (i.e., the cerebellar efferent cells of teleosts), such as the presence of spiny dendrites ascending to the molecular layer. Comparison of the afferent and efferent projections of the sturgeon cerebellum with those reported in teleosts supports the hypothesis that some traits observed in the teleost cerebellar system represent recent evolutionary developments. J. Comp. Neurol. 460:327–344, 2003. © 2003 Wiley‐Liss, Inc.
A note on incorporation of domain decomposition into the differential quadrature method
Authors: Zhong Hongzhi , He Yuhong
Published: April 2003

The incorporation of domain decomposition into the differential quadrature method (DQM) to deal with two‐dimensional problems is examined. Several issues involving necessity, implementation procedures and the resultant accuracy of solution are outlined and discussed through a typical plane elasticity example. It is observed that the differential quadrature in conjunction with domain decomposition is able to treat problems with curvilinear boundaries. High‐order serendipity elements yield better results in terms of efficiency and accuracy. In addition, it is also found that differential quadrature solution is sensitive to the aspect ratio of domains in the case of stress concentration. Copyright © 2003 John Wiley & Sons, Ltd.
The generation and linewidth control of terahertz waves by parametric processes
Authors: Shikata Junichi , Kawase Kodo , Ito Hiromasa
Published: April 2003

In this article, we discuss broadband‐tunable terahertz‐wave parametric generation (TPG) via stimulated polariton scattering and techniques for narrowing the output spectrum of sources based on this phenomenon. The TPG effect, which is observed when a LiNbO3 crystal is excited with nanosecond pulses from a Nd:YAG laser, has a gain bandwidth of over 500 GHz. After carrying out experiments aimed at converting the TPG effect into a high‐power source of terahertz waves, we used our TPG light source for Fourier spectroscopy in the terahertz band. In addition, we were able to narrow the spectral bandwidth of the terahertz emission down to the Fourier limit (spectral purity Δν/ν∼10−4) by applying the method of optical injection seeding to the TPG using light from a wavelength‐tunable semiconductor laser. When we used the light from this injection‐seeded TPG source for the spectroscopy of water vapor in the terahertz region, we confirmed a resolution below 100 MHz (0.003 cm−1). Our final version of an injection‐seeded TPG light source exhibited peak powers of over 300 mW (dynamic range > 106), and a frequency tunability of 0.7 to 2.4 THz. We anticipate that this compact nonlinear‐optics‐based terahertz wave light source, which can operate at ordinary temperatures and is structurally simple, can become an effective tool for scientific and technological research in the terahertz region. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(5): 52–65, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10047
Single‐photon detector for long‐distance quantum cryptography
Authors: Namekata Naoto , Makino Yuuki , Inoue Shuichiro
Published: April 2003

In order to realize long‐distance quantum cryptography based on standard optical fiber network, we have developed a single‐photon detector at 1550 nm using InGaAs/InP avalanche photodiodes (APDs). To reduce the dark count probability, APDs were cooled and operated with a Gated Passive Quenching Circuit. A quantum efficiency of 13.7% was obtained at −55 °C while keeping the dark count probability per gate (2 ns) as low as 2.4 × 10−5. In this paper we will discuss the performance of the developed single‐photon detector in view of application to quantum cryptography. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(5): 10–15, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10115
Adjusting for population heterogeneity: A framework for characterizing statistical information and developing efficient test statistics
Authors: Rabinowitz Daniel
Published: April 2003

The focus of this work is the TDT‐type and family‐based test statistics used for adjusting for potential confounding due to population heterogeneity or misspecified allele frequencies. A variety of heuristics have been used to motivate and derive these statistics, and the statistics have been developed for a variety of analytic goals. There appears to be no general theoretical framework, however, that may be used to evaluate competing approaches. Furthermore, there is no framework to guide the development of efficient TDT‐type and family‐based methods for analytic goals for which methods have not yet been proposed. The purpose of this paper is to present a theoretical framework that serves both to identify the information which is available to methods that are immune to confounding due to population heterogeneity or misspecified allele frequencies, and to inform the construction of efficient unbiased tests in novel settings. The development relies on the existence of a characterization of the null hypothesis in terms of a completely specified conditional distribution of transmitted genotypes. An important observation is that, with such a characterization, when the conditioning event is unobserved or incomplete, there is statistical information that cannot be exploited by any exact conditional test. The main technical result of this work is an approach to computing test statistics for local alternatives that exploit all of the available statistical information. Genet Epidemiol 24:284–290, 2003. © 2003 Wiley‐Liss, Inc.
Australia and New Zealand satellite coverage using a microstrip patch reflectarray
Authors: Zornoza J. A. , Bialkowski M. E.
Published: April 2003

This paper presents the design of Ku‐band (12.25–12.75 GHz) dual‐polarized reflectarrays for Optus B1 satellites to obtain a contoured beam for Australia and New Zealand. The specified radiation pattern is synthesized using a phase‐only synthesis method based on the concept of intersection approach. Having determined the phasing data, single‐ and double‐layer reflectarrays are designed using variable‐size rectangular patches. The performances of the two reflectarrays are assessed by comparing their radiation patterns with the assumed pattern. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 321–325, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10907
Full‐wave analysis of microstrip lines on a highly lossy substrate
Authors: Prakash V. V. S. , Kuzuoglu Mustafa , Mittra Raj
Published: April 2003

The finite‐element method has been used for analyzing open microstrip line structures on highly lossy substrates. The geometry descritization has been carried out by using quadrilateral elements, and the spurious solutions are avoided by employing tangential vector formulation. The difficulties associated with finding the propagation constant of a highly lossy structure by solving a generalized eigenvalue problem are discussed. A methodology is presented for a fast and efficient computation of the attenuation and propagation constants of the lossy transmission lines. Numerical results are presented to illustrate the application of the proposed approach for the case of an open microstrip line. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 325–329, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10908
A stacked suspended plate antenna
Authors: Chen Zhi Ning , Chia M. Y. W. , Lim Cheng Liang
Published: April 2003

This paper describes a stacked suspended probe‐fed plate antenna for broadband applications. The effects of changing the size of the upper plate and the distance between the upper and the lower plates on the impedance and radiation characteristics of the antenna are discussed numerically and experimentally. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 337–339, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10911
An improved intrinsic small‐signal equivalent circuit model of delta‐doped AlGaAs/InGaAs/GaAs HEMT for microwave frequency applications
Authors: Guru Vandana , Jogi Jyotika , Gupta Mridula , Vyas H. P. , Gupta R. S.
Published: April 2003

An improved model of a modified intrinsic equivalent circuit of delta‐doped AlGaAs/InGaAs/GaAs HEMT, which incorporates the additional capacitive effect physically present due to delta doping and a feedback resistor between gate and drain, is proposed. Admittance parameters of the device are extracted from circuit analysis and intrinsic circuit elements are presented in terms of real and imaginary parts of the admittance parameters. S parameters are also evaluated over the frequency range 1–26 GHz and show good agreement with experimental data. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 376–379, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10923
A new design technique for optical multipass cells modelled with arbitrary surfaces
Authors: Conde Olga M. , Cortés Pedro M. , López‐Higuera José M.
Published: April 2003

A novel parametric model for optical mirrors is proposed based on an advanced solids modelling technique to design and analyze optical systems. This new technique implements two ray‐tracing methods on the arbitrary parametric nature of optical mirror surfaces in order to provide a high degree of flexibility and avoid the typical restrictions of traditional canonical structures. The proposed technique is employed to design and optimize multipass cells used on gas‐sensing applications. Results are discussed and show that the technique can also be successfully used for analysis of optical resonators. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 383–387, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10925
Gene silencing by adenovirus‐delivered siRNA
Authors: Shen Changxian , Buck Andreas K , Liu Xiangwei , Winkler Michael , Reske Sven N
Published: April 2003

RNA interference is the process that double‐stranded RNA induces the homology‐dependent degradation of cognate mRNA mediated by 21–23 nucleotide short interfering RNA (siRNA). Here, we describe a simple virus vector for efficient delivery of siRNA into mammalian cells utilizing the well‐defined H1‐RNA promoter and conventional adenovirus. In this pilot study, p53 was targeted by this vector. Our results demonstrate efficient and specific knock‐down of p53 in breast cancer MCF‐7 and lung carcinoma A549 cells and indicate a prospective application of this siRNA expressing recombinant adenovirus system in functional genomics, cancer gene therapy and virus inhibition.
Paroxetine-induced enuresis
Authors: Toros Fevziye , Erdoğan Kubilay
Published: April 2003

I would like to include one case to the literature on children and adolescents who have developed enuresis while taking paroxetine. Up to now, the fact that enuresis may have occurred as a result of the side effect of using paroxetine was not reported in some articles and letters.