bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic stiffness vibration analysis using a high‐order beam model
Authors: Eisenberger Moshe 
Published: June 2003

AbstractThis work presents the derivation of the exact dynamic stiffness matrix for a high‐order beam element. The terms are found directly from the solutions of the differential equations that describe the deformations of the cross‐section according to the high‐order theory, which include cubic variation of the axial displacements over the cross‐section of the beam. The model has six degrees of freedom at the two ends, one transverse displacement and two rotations, and the end forces are a shear force and two end moments. Using the dynamic stiffness matrix exact vibration frequencies for beams with various combinations of boundary conditions are tabulated and compared with results from the Bernoulli–Euler and Timoshenko beam models. Copyright © 2003 John Wiley & Sons, Ltd.
Limits to growth in the new economy: exploring the ‘get big fast’ strategy in e‐commerce
Authors: Oliva Rogelio , Sterman John D. , Giese Martin 
Published: June 2003

AbstractMany e‐businesses have pursued a ‘get big fast’ (GBF) strategy, pricing low and marketing heavily to build their user base, in the belief that there were significant sources of increasing returns favoring early entrants and large players. Until early 2000 the capital markets rewarded the GBF strategy, but since then market values have collapsed and scores of new‐economy firms have failed. The rise and fall of the dot coms is not merely a case of a speculative bubble. Many firms stumbled when they grew so rapidly that they were unable to fulfill orders or provide quality service. GBF proponents focus on the positive feedbacks that create increasing returns and favor aggressive firms, but have not paid adequate attention to the negative feedbacks that can limit growth, e.g., service quality erosion. The faster a firm grows, the stronger these negative feedbacks may be. We address these issues with a formal dynamic model of competition among online and click‐and‐mortar companies in business‐to‐consumer e‐commerce. The model endogenously generates demand, market share, service quality, employee skill and retention, content creation, market valuation, and other key variables. The model is calibrated to the online book market and Amazon.com as a test case. We explore growth strategies for e‐commerce firms and their sustainability under different scenarios for customer, competitor, and capital market behavior. Copyright © 2003 John Wiley & Sons, Ltd.
Three‐dimensional ultrasound imaging of the pelvic floor: the effect of parturition on paravaginal support structures
Authors: Dietz H. P. , Steensma A. B. , Hastings R. 
Published: June 2003

AbstractObjectiveIt is assumed that support of the female urethra and bladder is maintained by paraurethral and paravaginal fascial structures, with hypermobility resulting from delivery‐related trauma. This study used three‐dimensional translabial ultrasound to assess these structures and document peripartal changes.DesignA clinical observational pilot study was performed on 26 nulliparous women recruited in the third trimester of pregnancy. They underwent translabial two‐ and three‐dimensional ultrasound. Twenty‐three women were again seen 2–5 months postpartum. The assessor was blinded against two‐dimensional ultrasound and delivery data. Vaginal tenting was rated as being present, indeterminate or absent at each of three levels, and was correlated with bladder neck descent (BND) and urethral rotation on Valsalva maneuver.ResultsTenting was visible at all levels in 21 of 26 women antepartally. In three women tenting was absent on one level; in two cases tenting was rated indeterminate. There was no significant difference in BND between women with visible tenting and those without. The BND range for women with intact tenting was 5.4–41.6 mm. Twenty‐one of the 26 women were included in the postpartum analysis. Of these, obvious peripartal changes were documented in five. Loss of tenting did not correlate significantly with changes in BND.ConclusionsMost nulliparous women showed evidence of intact paravaginal support structures. Tenting occurred in women with widely varying BND, implying that excess bladder neck mobility may be due to increased fascial compliance. Postnatally, fascial disruption was suspected in a minority of patients only. In some women delivery‐related changes may be due to attenuation rather than disruption of structures. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Multiple fetal anomalies associated with subtle subtelomeric chromosomal rearrangements
Authors: Souter V. L. , Glass I. A. , Chapman D. B. , Raff M. L. , Parisi M. A. , Opheim K. E. , Disteche C. M. 
Published: June 2003

AbstractWe report two cases of multiple fetal anomalies detected by prenatal ultrasound and associated with subtle subtelomeric chromosomal rearrangements. The first case presented at 25 weeks of gestation with an enlarged cisterna magna and ventriculomegaly. Karyotyping of amniocytes showed a subtle terminal abnormality of chromosome 6q. Thereafter, screening of all unique chromosomal subtelomeric regions using a panel of telomere‐specific, fluorescence in situ hybridization (FISH) probes revealed an unbalanced reciprocal translocation between 6q and 17p [46,XX.ish der(6)t(6;17)(q25.3;p13)(TelVysion6q‐;TelVysion17p+)]. The second case presented at 25 weeks of gestation with tetralogy of Fallot and at 34 weeks of gestation had additional ultrasound findings of an arachnoid cyst and intrauterine growth restriction. Postnatal karyotyping of peripheral blood was performed and appeared normal. However, a cryptic deletion of the subtelomeric region of the long arm of chromosome 14 was identified when the infant's blood sample was used as a control for an oncology FISH probe. Thereafter, screening of all unique chromosomal subtelomeric regions using a panel of telomere‐specific FISH probes revealed an unbalanced reciprocal translocation of chromosomes 14q and 20p [46,XY.ish der(14)t(14;20)(q32.3;p13)(IGH‐, D14S308‐,TelVysion20p+)mat]. These two cases add to a growing number of reports of cryptic subtelomeric chromosomal rearrangements associated with congenital anomalies. This is the first report of multiple, simultaneous FISH screening of the subtelomeric regions in amniotic fluid and has demonstrated the technical feasibility of this technique in the prenatal period. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Nuchal translucency thickness measurement: repeatability using a virtual ultrasound scanner
Authors: Newey V. R. , Nassiri D. K. , Bhide A. , Thilaganathan B. 
Published: June 2003

AbstractAimTo use a PC‐based virtual ultrasound scanner (VirUS) in the investigation of inter‐ and intraoperator nuchal translucency (NT) thickness measurement repeatability of experienced ultrasound operators.MethodsRealistic fetal ultrasound images of defined NT thickness were simulated with VirUS with emulation of scanner gain and time‐gain compensation and gain‐dependent echo size changes. A set of 50 images was generated with uniformly distributed NT thickness (range, 1–5 mm at 1‐mm intervals) and translucency angle (mean ± standard deviation of ± 2.52° ± 1.85° about the horizontal). Operators (n = 13) measured NT thickness in the image set on three occasions separated by at least 1 day, giving 150 measurements per operator (total measurements, 1950).ResultsInter‐ and intraoperator repeatabilities were ± 0.41 mm and ± 0.22 mm, respectively (at the 95% confidence level). There were significant correlations between repeatability and mean measured NT thickness (r = − 0.72, P = 0.005 at 4‐mm interval), between gain and mean measured NT thickness (P ≤ 0.002, n = 8/13) and between gain and repeatability coefficient (P < 0.01, n = 6/13).DiscussionVirUS provides a consistent NT audit environment and demonstrates the need to both optimize repeatability vs. mean measured thickness and to set gain consistently. The technique has potential in operator training. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal detection of velamentous insertion of the umbilical cord: a prospective color Doppler ultrasound study
Authors: Sepulveda W. , Rojas I. , Robert J. A. , Schnapp C. , Alcalde J. L. 
Published: June 2003

AbstractObjectiveVelamentous insertion of the umbilical cord, with a reported incidence of 1% in singleton pregnancies, has been associated with several obstetric complications including fetal growth restriction, prematurity, congenital anomalies, low Apgar scores, fetal bleeding and retained placenta. The aim of this study was to determine the feasibility of identifying velamentous insertion of the umbilical cord during routine obstetric ultrasound.DesignThis was a prospective, cross‐sectional ultrasound study in 832 unselected second‐ and third‐trimester singleton pregnancies. Color Doppler ultrasound was routinely performed to identify the placental cord insertion site. The role of three‐dimensional (3D) ultrasound in evaluating the placental cord insertion site was also studied in a subset of 50 pregnancies from this population.ResultsThe placental cord insertion site was identified in 825/832 (99%) cases. Visualization was not achieved in seven third‐trimester pregnancies with a posterior placenta. A velamentous insertion was suspected prenatally in eight cases, seven of which were confirmed after delivery as velamentous and one as markedly eccentric (battledore placenta). 3D ultrasound performed poorly at evaluating placental cord insertion site, being less efficient due to poor‐quality resolution and far more time‐consuming than the combined use of gray‐scale and color Doppler ultrasound.ConclusionsVelamentous insertion of the umbilical cord can reliably be detected prenatally by gray‐scale and color Doppler ultrasound. 3D imaging had limited value in the evaluation of the placental cord insertion site in our subset of patients. Systematic assessment of the placental cord insertion site at routine obstetric ultrasound has the potential of identifying pregnancies with velamentous insertion and, therefore, those at risk for obstetric complications including vasa previa. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Arteriovenous malformation of the uterus associated with secondary postpartum hemorrhage
Authors: Kelly S. M. , Belli A. M. , Campbell S. 
Published: June 2003

AbstractWe present the case of a young woman with persistent secondary postpartum hemorrhage. Transvaginal imaging demonstrated an irregular pulsatile lesion in the anterior myometrium. Color Doppler analysis revealed the presence of abnormal vessels consistent with an arteriovenous malformation. Typically this vascular abnormality had a turbulent pattern of arterial and venous flow with high peak velocities and low resistance. The patient was treated with selective arterial embolization leading to a full recovery. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Spatial distribution and intensity of barrier plasma for surface treatment
Authors: Ermel V. , Förster F. , Lindmayer M. , Prinz E. 
Published: June 2003

AbstractTechnische Anwendungen von Barrierenladungen an Luft bei Atmosphärendruck gewinnen immer mehr an Bedeutung auf dem Markt der Plasmatechnologien, weil sie eine umweltschonende und preiswerte Alternative zu anderen Verfahren der Oberflächenbehandlung bieten. Diese Plasmen bestehen üblicherweise aus einer Vielzahl räumlich und zeitlich eng begrenzter Filamente, deren Verteilung zur Erzielung homogener Behandlungsergebnisse möglichst gleichmäßig sein sollte. Dies gilt insbesondere für die Plasmabehandlung empfindlicher Medien wie Wolle oder anderer Textilien. In Anlagen zum kontinuierlichen Durchlauf bestehen die Barrieren‐Anordnungen oft aus einem System Walze – Walze oder Walze – Ebene, wobei die Gasspaltweite ortsabhängig variiert. Die Intensität und Verteilung der Filamente wird durch optische Kurzzeitaufnahmen sowie durch ortsaufgelöste Messung der Stromverteilung und der daraus abgeleiteten Energieverteilung untersucht. Die gemessene Ortsabhängigkeit kann mit Hilfe eines kapazitiven Ersatzschaltbildes erklärt werden.
Interdisciplinary atomism? Exploring twentieth-century culture through Einstein Marcia Bartusiak,Einstein's Unfinished Symphony: Listening to the Sounds of Space–Time. Washington, DC: Joseph Henry Press, 2000. Pp. xii+249. ISBN 0-309-06987-4. £17.95 (hardback). Alice Calaprice (ed.), The Expanded Quotable Einstein. With a foreword by Freeman Dyson. Princeton and Oxford: Princeton University Press, 2000. Pp. xliii+407. ISBN 0-691-07021-0. £11.95, $18.95 (cloth). Klaus Hentschel (ed.), Physics and National Socialism: An Anthology of Primary Sources. Ann M. Hentschel, Editorial Assistant and Translator. Erwin Hiebert and Hans Wussing (eds.), Science Networks: Historical Studies, 18. Basel, Boston and Berlin: Birkhäuser, 1996. Pp. ci+406+civ. ISBN 3-7643-5312-0. DM 178.00, SFR 148.00, €98.00 (cloth). Gerald Holton,Einstein, History, and Other Passions: The Rebellion Against Science at the End of the Twentieth Century. Cambridge and London: Harvard University Press, 2000. Pp. xii+240. ISBN 0-674-00433-7. £12.50 (paperback). Don Howard and John Stachel (eds.), Einstein: The Formative Years, 1879–1909. Einstein Studies, 8. Boston, Basel and Berlin: Birkhäuser, 2000. Pp. xi+258. ISBN 0-8176-4030-4. DM 128.00, €83.00, SFR 124.00. Arthur I. Miller,Einstein, Picasso: Space, Time and the Beauty that Causes Havoc. New York: Basic Books, 2001. Pp. x+357. ISBN 0-465-01859-9. $30.00, CAN$44.95 (cloth).
Authors: STALEY RICHARD 
Published: June 2003

‘If it didn't have Einstein's name on it, would you give a damn?’
Nobel laureate Philip Anderson, critiquing proposals for the Laser Interferometer Gravitational-Wave
Observatory in 1990Interest in Einstein's work and name shows little sign of abating in either scholarly or popular circles. The books reviewed here range from a collection of primary sources and research papers devoted to fine points of detail, through to cultural commentary and popular studies of Einstein's work and its legacy; their most common general concern is with the place science holds in broader culture.
Morphosyntactic constructs in the development of spoken and written Hebrew text production
Authors: RAVID DORIT , ZILBERBUCH SHOSHANA 
Published: June 2003

This study examined the distribution of two Hebrew nominal structures – N–N compounds and denominal adjectives – in spoken and written texts of two genres produced by 90 native-speaking participants in three age groups: eleven/twelve-year-olds (6th graders), sixteen/seventeen-year-olds (11th graders), and adults. The two constructions are later linguistic acquisitions, part of the profound lexical and syntactic changes that occur in language development during the school years. They are investigated in the context of learning how modality (speech vs. writing) and genre (biographical vs. expository texts) affect the production of continuous discourse.Participants were asked to speak and write about two topics, one biographical, describing the life of a public figure or of a friend; and another, expository, discussing one of ten topics such as the cinema, cats, or higher academic studies. N–N compounding was found to be the main device of complex subcategorization in Hebrew discourse, unrelated to genre. Denominal adjectives are a secondary subcategorizing device emerging only during the late teen years, a linguistic resource untapped until very late, more restricted to specific text types than N–N compounding, and characteristic of expository writing. Written texts were found to be denser than spoken texts lexically and syntactically as measured by number of novel N–N compounds and denominal adjectives per clause, and in older age groups this difference was found to be more pronounced. The paper contributes to our understanding of how the syntax/lexicon interface changes with age, modality and genre in the context of later language acquisition.
Creating a computer-based language learning environment
Authors: BARR J. DAVID , GILLESPIE JOHN H. 
Published: June 2003

This paper considers key questions concerning computer-based language-learning environments.
Using evidence from current literature, it discusses the main characteristics of such environments including
human, technical and physical resources, communicative structures, information management, and cultural contexts.
It then uses data from an investigation of the universities of Cambridge, Toronto and Ulster to assess the
pedagogical effectiveness of the computer-based environments currently in operation in these three
institutions.It considers, in particular, the integrative role that computer-based language learning environments
seem to provide. Although each institution has integrated computer technology into language teaching and learning
in different ways, a key element of each environment has been the establishment of a common computer-mediated
infrastructure, enabling effective information dissemination, resource distribution, communication and
teaching and learning. No single common infrastructure would be suitable in all three, however, in each case,
it was found that the environments created were valuable, especially in integrating elements of the teaching
and learning process that would normally have remained apart.In concluding that the creation of a computer-based
language learning environment in the present climate is beneficial, it was noted that adequate technical
resources and a management that is keen to integrate computer technology into all aspects of university life
is a key factor in their success.
Cadaveric organ donor recruitment at Los Angeles County Hospital: improvement after formation of a structured clinical, educational and administrative service
Authors: Roth Bradley J , Sher Linda , Murray James A , Belzberg Howard , Mateo R , Heeran A , Romero Javier , Mone Tom , Chan Linda , Selby Rick 
Published: June 2003

Abstract: Background/Aims: There remains a critical shortage of cadaveric organs. At a large inner city level one trauma centre, several strategies were devised and combined to (a) optimize the physiologic status of potential donors, (b), promote awareness of the donation process among health care professionals and (c) perform quality control on the organ donation system − all in an effort to improve organ donation rates. Resuscitative and maintenance protocols were devised and implemented through a multidisciplinary team approach for patients diagnosed with brain death. We report the effect this approach has had on organ donation in a single centre.Method: A death record review (DRR) by the local organ procurement agency (OPO) was used to identify the number of patients diagnosed with brain death at Los Angeles County Hospital each year from 1995 through 2001. Data were collected to determine the number of these potential donors that eventually underwent organ donation. Data were collected for two time intervals: Phase I (1995–98) and Phase II (1999–2001). During Phase I, there was no focused institutional programme for the approach to potential donors. During Phase II, an institutional programme including the following characteristics was implemented: 1) donor resuscitation protocol, 2) assignment of a dedicated OPO coordinator liaison to interact with families, hospital personnel and the coroner's office, 3) assignment of the primary role of stabilization and care of potential donors and the integration of all medical services to the trauma service, and 4) biweekly conferences to review policies, protocols, and outcomes of donor management strategies.Results: From 1995 to 2001 there was a large increase in patient referrals for donor evaluation from 86 (Phase I) to 124 (Phase II). There was a smaller increase in the number of suitable donors: Phase I (mean: 51/year) and Phase II (mean: 63/year). There was, however, an increase in the mean number of actual organ donors from 14.2/year to 25.7/year from Phase I to Phase II and an increase in organs donated from 29 to 49. Organ donor declines decreased from 53% (Phase I) to 39% (Phase II).Conclusions: Strategies to increase the number of cadaveric organs available for organ transplantation are crucial. A strategy combining prompt identification of potential organ donors, institution of resuscitative protocols, a multidisciplinary team approach, educational activities and utilization of personnel expert in organ procurement led to a marked increase in the number of organ donors and the number of organs donated at a single institution. Wider application of this approach should prove successful in increasing organ donation in a similar fashion in other institutions.
Cold ischaemia time added to kidneys can be minimized by completing the final cross‐match before organs are taken from the operating room
Authors: Bryan Christopher F ,   for the Midwest Transplant Network Organ Procurement Organization Organ Procurement Coordinators,   Renal Placement Coordinators,   Histocompatibility Medical Technologists,   Pilots
Published: June 2003

Abstract: Purpose:Minimizing the amount of cold ischaemia time (CIT) added to cadaveric kidneys before their transplantation is an important goal since longer CIT is associated with worse long‐term graft outcome. Our organ procurement organization (OPO) and HLA laboratories have taken the approach of performing the histocompatibility testing, including the final cross‐match, as early in the donor process as possible.Methods:The data in this study were collected from all consecutive final cross‐matches done for cadaveric kidney (n = 113) and simultaneous pancreas + kidney (SPK) (n = 25) transplants done with organs recovered from donors in the Midwest Transplant Network OPO from 1 January 2001 to 9 May 2002. We evaluated the time the final cross‐match was completed from when the kidneys from that donor were taken from the operating room (OR) and compared that time with CIT.Results:For kidney transplants, 72% of the final cross‐matches were complete before the kidneys were taken from the OR. The CIT of that group (10.4 ± 3.8 h) was significantly lower than that of the group of kidney transplant patients whose final cross‐match was done after the kidneys were taken from the OR (15.5 ± 5.8 h) (P < 0.001). Similarly, for SPK transplants, 88% of the final cross‐matches were completed before the organs left the OR and the CIT of that group (10.2 ± 3.4 h) was less than in the group whose final cross‐match was done after the organs left the OR (14.3 ± 4.8 h) (P > 0.1).Conclusions:These data show that the practice of completing the final cross‐match as early in the donor process as possible helps to minimize the amount of cold ischaemia time added to the kidneys and pancreata before transplantation. That should reduce the detrimental influence that longer CIT has on short‐ and long‐term function in kidney as well as SPK transplantation.