bluuebunny/crossref_metadata_2025 huggingface dataset:
The theory of instantaneous power in three‐phase four‐wire systems and its applications
Authors: Akagi Hirofumi , Ogasawara Satoshi , Kim Hyosung
Published: August 2002

This paper discusses “thep–qtheory” and “the cross‐vector theory” in three‐phase four‐wire systems, with the focus on similarities and differences between the two theories. They are perfectly identical if no zero‐sequence voltage is included in a three‐phase three‐wire system. However, they are different in definition of the instantaneous active power and instantaneous reactive power in each phase if a zero‐sequence voltage or current is included in a three‐phase four‐wire system. Based on both theory and computer simulation, this paper leads to the following conclusions: An instantaneous reactive‐power compensator without energy storage components can fully compensate for the neutral current even in a three‐phase four‐wire system including a zero‐sequence voltage or current, when a proposed control strategy based on thep–qtheory is applied: However, the compensator cannot compensate for the neutral current fully, when a conventional control strategy based on the cross‐vector theory is applied. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 74–86, 2001
A transformer resonant phase‐shifted PWM DC–DC converter for X‐ray power generator and its fuzzy logic‐based learning control scheme
Authors: Sun Junming , Takano Hiroshi , Nakaoka Mutsuo
Published: August 2002

In general, medical‐use high‐voltage X‐ray power generators are operated at a variety of required output DC voltages and output current settings for the X‐ray tube. A phase‐shifted PWM inverter‐fed DC–DC power converter with a high‐voltage transformer parasitic resonant link which is used for an X‐ray power generator inherently has stiff nonlinear characteristics due to phase‐shifted voltage regulation and diode cutoff operation in a high‐voltage rectifier because of the wide load setting ranges in practical applications. However, the superior output voltage response required for a medical‐use X‐ray power generator could not be sufficiently implemented by various modern linear control approaches because a precise mathematical description with dynamic modeling could not be formulated for wide load variations. For controlling such a nonlinear DC–DC power conversion system, a fuzzy reasoning‐based learning control technique that duplicates human capabilities and much experience in understanding the dynamic and static behavior of the system are more suitable and effective. This paper presents a phase‐shifted PWM full bridge inverter‐type high‐voltage DC–DC power converter with a high‐voltage transformer parasitic link and its fuzzy‐based learning controller, which has excellent dynamic and static behavior, for use in a medical X‐ray power generator operating at a wide variety of load settings. The effectiveness of the feasible fuzzy learning technique used for control of the DC–DC power converter is discussed and evaluated based on computer simulations and experimental results in a laboratory setup. It is demonstrated that the feasible fuzzy learning control scheme suitable for this converter is more effective and practical in improving the system output voltage response performance in both transient and steady states for medical‐use X‐ray power generators. The results of simulations and experiments for this converter are presented in order to illustrate the operating performance of the proposed X‐ray power generator operated by the feasible fuzzy‐based learning control implementation. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 58–71, 2001
Chemoprevention of heterocyclic amine‐induced mammary carcinogenesis in rats
Authors: Hirose Masao , Nishikawa Akiyoshi , Shibutani Makoto , Imai Toshio , Shirai Tomoyuki
Published: August 2002

2‐Amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) is one of the most prevalent carcinogenic heterocyclic amines in the environment, targeting the colon, prostate, pancreas, and mammary gland in rodents. Chemopreventive effects of synthetic and naturally occurring compounds on PhIP‐induced rat mammary carcinogenesis were investigated in a series of experiments. In a PhIP feeding model, groups of 20–21 female F344 rats each, were treated with 0.02% PhIP alone or PhIP plus 0.5% 1‐O‐hexyl‐2,3,5‐trimethylhydroquinone (HTHQ), 1% green tea catechins, 1% α‐tocopherol, 0.1% ellagic acid, or 1% chlorophyllin, each in the diet, or 0.1% caffeine in drinking water for 52 weeks. To assess the mechanism of HTHQ and caffeine inhibition of PhIP‐induced carcinogenesis, effects of these compound on the in vitro metabolic activation of PhIP were examined in the presence of S9 mix. In the next series of experiments, the PhIP intragastric dose model was applied to allow separate investigation of the effects of chemicals during the initiation and postinitiation periods. In these experiments, female Sprague–Dawley rats were given eight intragastric doses of 100 mg/kg body weight during the first 4–8 weeks for initiation. Either during initiation or after initiation, or only after initiation, animals were treated with either corn or perilla oil at doses of 5 and 20%, conjugated fatty acid derived from safflower oil (CFA‐S) or perilla oil (CFA‐P) at a dose of 1%, arctiin at doses of 0.02 and 0.2% in the diet, or sodium nitrite (NaNO2) at a dose of 0.2% in drinking water. In the PhIP feeding model, administration of PhIP alone for 52 weeks induced adenocarcinomas in 40% of rats, but the incidence was remarkably reduced to 5% by the simultaneous treatment with 0.5% HTHQ, a strong lipophilic phenolic antioxidant, or to 10% by 0.1% caffeine. Administration of 1% chlorophyllin exerted similar, albeit weaker, effects. α‐Tocopherol at a dose of 0.5% only reduced the multiplicity of carcinomas, and 1% green tea catechins only the mean size of mammary tumors. In a metabolic activation study of PhIP, HTHQ and caffeine clearly inhibited the formation of metabolites. In the PhIP gastric dose model, among the naturally occurring compounds examined, a plant lignan arctiin, perilla oil, which contains a large amount of n‐6 α‐linolenic acid, and CFA‐S or CFA‐P inhibited mammary tumor development, particularly in the postinitiation period, although a clear dose response was not observed. Treatment with 0.2% NaNO2 in the initiation period was found to lower the volume of mammary tumors. The present results indicate that a number of compounds may be candidate chemopreventive agents against PhIP‐induced mammary carcinogenesis, acting through different mechanisms and depending on the stage of carcinogenesis. Environ. Mol. Mutagen. 39:271–278, 2002. © 2002 Wiley‐Liss, Inc.
Predictive distributions in risk analysis and estimation for the triangular distribution
Authors: Joo Yongsung , Casella George
Published: August 2002

Many Monte Carlo simulation studies have been done in the field of risk analysis. This article demonstrates the importance of using predictive distributions (the estimated distributions of the explanatory variable accounting for uncertainty in point estimation of parameters) in the simulations. We explore different types of predictive distributions for the normal distribution, the lognormal distribution and the triangular distribution. The triangular distribution poses particular problems, and we found that estimation using quantile least squares was preferable to maximum likelihood. Copyright © 2001 John Wiley & Sons, Ltd.
Confidence intervals for the calibration estimator with environmental applications
Authors: Müller I. , El‐Shaarawi A. H.
Published: August 2002

The article investigates different estimation techniques in the simple linear controlled calibration model and provides different types of confidence limits for the calibration estimator. In particular, M‐estimation and bootstrapping techniques are implemented to obtain estimates of regression parameters during the training stage. Moreover, bootstrap is used to construct several types of confidence intervals that are compared to the classical approach based on the assumption of normality. For some of these intervals, the second order asymptotic properties can be established by means of Edgeworth expansions. Two data sets—one on space debris and the other on bacteriological counts in water samples—are used to illustrate the method's environmental applications. Copyright © 2002 John Wiley & Sons, Ltd.
Active interaction control of civil structures. Part 1: SDOF systems
Authors: Zhang Yunfeng , Iwan W. D.
Published: August 2002

This paper presents a family of semi‐active control algorithms termed as active interaction control (AIC) used for seismic response control of civil structures. AIC control algorithms include active interface damping (AID), optimal connection strategy (OCS) and tuned interaction damping (TID). A typical SDOF AIC system consists of a primary structure, an auxiliary structure and an interaction element. The auxiliary structure typically has stiffness comparable to that of the primary structure while its natural frequency is much higher than that of the primary structure. Interactions between the primary and the auxiliary structures are defined by specific AIC control logic such that vibrational energy is extracted from the primary structure into the auxiliary structure during a locking phase and dissipated in the auxiliary structure in the subsequent unlocking phase. The stability of AIC control algorithms is shown using the Lyapunov direct method. The efficacy of AIC control algorithms is demonstrated by the results of numerical simulations of SDOF systems subjected to seismic ground motions. Practical issues such as sampling period and time delay are also investigated in this study. Copyright © 2001 John Wiley & Sons, Ltd.
Performance evaluation of new steel frame buildings for seismic loads
Authors: Lee Kihak , Foutch Douglas A.
Published: August 2002

The damage observed after the Northridge Earthquake exposed a weakness of design and construction procedures and led to the development of performance‐based guidelines for design of new steel frame structures. As part of Phase 2 of the FEMA/SAC project, this study focused on performance prediction of new steel special moment resisting frame buildings assumed to be built after the Northridge earthquake. A total of 26 post‐Northridge buildings that represent typical steel SMRF buildings based on the new seismic code (1997 NEHRP) and pre‐qualified post‐Northridge connections were designed. Then, the analytical building models considering the effects of ductile connections, panel zone deformation and interior gravity frames were developed and subjected to sets of 20 SAC ground motions representing the 2/50 and 50/50 hazard levels. A new procedure that allows the design professional to determine the confidence level for achieving a given performance objective is presented. Using the drift demand and capacities, confidence levels that post‐Northridge buildings will satisfy the collapse prevention and immediate occupancy performance level are calculated. All of the post‐Northridge buildings exhibit a high confidence of performing well in future earthquakes. Copyright © 2001 John Wiley & Sons, Ltd.
Essential oil composition of Zanthoxylum alatum seeds from northern India
Authors: Jain Neetu , Srivastava S. K. , Aggarwal K. K. , Ramesh S. , Kumar Sushil
Published: August 2002

The seeds of Zanthoxylum alatum Roxb., on hydrodistillation, gave 1.5% of oil (v/w). GC and GC–MS analysis of the oil resulted in the identification of 56 constituents, representing 99.5% of the oil. Linalool (71%), limonene (8.2%), β‐phellandrene (5.7%) and (Z)‐methylcinnamate (4.9%) were the major components. It is suggested that the seeds of Z. alatum can be used as a commercial source for the isolation of linalool. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of volatile compounds released during the consumption of Cheddar cheese with compounds extracted by vacuum distillation using gas chromatography–olfactometry
Authors: O'Riordan P. J. , Delahunty C. M.
Published: August 2002

Buccal headspace analysis is an in vivo extraction technique capable of extracting volatile compounds released during consumption in concentration ratios that stimulate the olfactory receptors. Vacuum distillation is designed to measure the total volatile profile of a food and as a result pays little attention to conditions in the mouth that determine volatile release and aroma stimulation. Volatile extracts of mature Cheddar cheese were obtained using buccal headspace analysis and vacuum distillation. Cheddar cheese volatile extracts were compared using gas chromatography–olfactometry and gas chromatography–mass spectrometry. Estimation of odour intensity was carried out using a time–intensity gas chromatography–olfactometry technique similar to OSME. Odour‐active volatile compounds identified in Cheddar cheese buccal headspace analysis extracts included dimethyl sulphide, 2,3‐butanedione, 3‐methylbutanal, toluene, ethyl butyrate, hexanal, 2‐heptanone, heptanal, α‐pinene, methional, ethyl hexanoate and dimethyl trisulphide. All of these volatile compounds have previously been associated with the volatile profile of Cheddar cheese. Vacuum distillation obtained a near‐complete volatile extract of Cheddar cheese, which was distinguished from buccal headspace analysis extracts by the presence of low vapour pressure odour‐active volatile compounds. Significant differences (p < 0.05) between extractions were determined for the quantities of ethyl butyrate, 2‐heptanone and ethyl hexanoate, the odours of which were also identified in both extractions. Buccal headspace analysis and vacuum distillate principal aromagrams of mature Cheddar cheese were obtained using non‐centred principal components analysis. Qualitative odour differences were observed between both extractions, in particular for odour intensity measurements of one odour, ‘raw mushroom’. Tentative relationships between gas chromatography–olfactometry odour intensity measurements and corresponding gas chromatography–mass spectrometry quantitative measurements were established. Copyright © 2001 John Wiley & Sons, Ltd.
A σ‐coordinate three‐dimensional numerical model for surface wave propagation
Authors: Lin Pengzhi , Li C. W.
Published: August 2002

A three‐dimensional numerical model based on the full Navier–Stokes equations (NSE) inσ‐coordinate is developed in this study. Theσ‐coordinate transformation is first introduced to map the irregular physical domain with the wavy free surface and uneven bottom to the regular computational domain with the shape of a rectangular prism. Using the chain rule of partial differentiation, a new set of governing equations is derived in theσ‐coordinate from the original NSE defined in the Cartesian coordinate. The operator splitting method (Li and Yu,Int. J. Num. Meth. Fluids1996;23: 485–501), which splits the solution procedure into the advection, diffusion, and propagation steps, is used to solve the modified NSE. The model is first tested for mass and energy conservation as well as mesh convergence by using an example of water sloshing in a confined tank. Excellent agreements between numerical results and analytical solutions are obtained. The model is then used to simulate two‐ and three‐dimensional solitary waves propagating in constant depth. Very good agreements between numerical results and analytical solutions are obtained for both free surface displacements and velocities. Finally, a more realistic case of periodic wave train passing through a submerged breakwater is simulated. Comparisons between numerical results and experimental data are promising. The model is proven to be an accurate tool for consequent studies of wave‐structure interaction. Copyright © 2002 John Wiley & Sons, Ltd.
Consistent chromosome 10 rearrangements in four newly established human hepatocellular carcinoma cell lines
Authors: Pang Elizabeth , Wong Nathalie , Lai Paul B.‐S. , To Ka‐Fai , Lau Wan‐Yee , Johnson Philip J.
Published: August 2002

Cancer cell lines represent an invaluable resource for isolation of novel genes relevant to tumor pathogenesis and as in vitro models. In this study, we report on the successful establishment of four cell lines from hepatocellular carcinoma tissue. These cell lines, designated HKCI‐1, HKCI‐2, HKCI‐3, and HKCI‐4, have been growing continuously for more than 24 months and have been passaged more than 50 times. A comprehensive cytogenetic characterization on the primary tumors and the derived cell lines was achieved by the combined approach of spectral karyotyping and comparative genomic hybridization. Chromosomal imbalances from the primary tumors were also maintained in the cell lines and included gains of 1q, 6p, 7, 10p, 17q, and 20 and loss of 4q. Recurring translocations included t(X;11), t(1;10), t(4;16), i(5)(p10), t(7;21), t(8;17), t(9;22), i(10)(p10), t(14;20), t(16;22), and t(17;19). It was noteworthy that consistent chromosome 10 aberrations, in particular t(1;10)(q10;p10), were detected in all four cell lines. Furthermore, microsatellite analysis on primary tumor and derived cell lines indicated a common deleted region of 10q23‐q26. The functional importance of chromosome 10 aberrations in relation to the pathogenesis of HCC is unknown; however, the high frequency with which such aberrations were maintained in the cell lines suggests proliferative advantages of 10q loss or 10p gain in the multistep development of hepatic neoplasia. © 2002 Wiley‐Liss, Inc.
Darwin would be proud: Bioturbation, dynamic denudation, and the power of theory in science
Authors: Johnson D. L.
Published: August 2002

Charles Darwin's worm book influenced many early researchers who, following his lead, demonstrated how soil biota mechanically generate new strata and soil horizons, as well as blur or destroy them. Such early observations on biomechanical processes failed to find visibility in our models of landscape evolution for several reasons, chief of which are (1) except for ichnology, an Earth sciences tradition of adopting frameworks where biomechanical processes are absent and (2) a lapse of over 100 years after Darwin before a genetic language backed by supporting theory appeared that could showcase the importance of such processes. Examples of influential Earth science frameworks in which biomechanical processes are absent are the V.V. Dokuchaev–USDA–H. Jenny soil formational (five factors) paradigm, W.M. Davis' geographical cycle, the W. Penck–L.C. King–R.V. Ruhe backwasting‐pedimentation concept, the stratigraphic Law of Superposition, and other traditional approaches to archaeology, geomorphology, and pedology. Examples of recent genetic language that serve to ameliorate the problem are soil thickness concepts, biomantle, bioturbation, faunalturbation, floralturbation, and pedoturbation. Examples of recent supporting theory that incorporate biomechanical processes are soil evolution, biomantle evolution, dynamic pedogenesis, and the dynamic denudation framework advocated here. Dynamic denudation is a unified synthesis that elevates bioturbation to parity levels with other major archaeogenic, geomorphogenic, and pedogenic processes. The general framework and its principal elements are summarized and simulated by diagrams and augmented by photographs taken in disparate parts of the world. The model has useful explanatory and predictive value in archaeology, geomorphology, pedology, and other surficial process research. © 2002 John Wiley & Sons, Inc.
The cerebellar deficient folia (cdf) gene acts intrinsically in Purkinje cell migrations
Authors: Park Chankyu , Finger Jacqueline H. , Cooper Jonathan A. , Ackerman Susan L.
Published: August 2002

Summary: Cerebellar deficient folia (cdf) is a recently identified mouse mutation causing ataxia and cerebellar abnormalities including lobulation defects and abnormal placement of a specific subset of Purkinje cells. To understand the etiology of the cerebellar defects in cdf mutant mice, we examined postnatal development of the cdf/cdf cerebellum. Our results demonstrate that Purkinje cell ectopia and foliation defects are apparent at birth, suggesting the cdf mutation disrupts the positioning of many, but not all, Purkinje cells during development. In addition to cerebellar abnormalities, we observed lamination defects in the hippocampus of cdf mutant mice, although neocortical defects were not seen. Furthermore, ectopic Purkinje cells in cdf/cdf mice express an increased level of Dab1 protein, as previously observed in mice with mutations in genes in the reelin signaling pathway. Lastly, analysis of cdf ↔ROSA26 chimeric mice demonstrated that the cdf mutation is intrinsic to Purkinje cells. We suggest that the cdf gene product is required in a subset of Purkinje cells, possibly to respond to Reelin signals. genesis 32:32–41, 2002. © 2002 Wiley‐Liss, Inc.
Quaking is essential for blood vessel development
Authors: Noveroske Janice K. , Lai Lihua , Gaussin Vinciane , Northrop Jennifer L. , Nakamura Hisashi , Hirschi Karen K. , Justice Monica J.
Published: August 2002

For nearly 40 years functional studies of the mouse quaking gene (qkI) have focused on its role in the postnatal central nervous system during myelination. However, the homozygous lethality of a number of ENU‐induced alleles reveals that quaking has a critical role in embryonic development prior to the start of myelination. In this article, we show that quaking has a previously unsuspected and essential role in blood vessel development. Interestingly, we found that quaking, a nonsecreted protein, is expressed in the yolk sac endoderm, adjacent to the mesodermal site of developing blood islands, where the differentiation of blood and endothelial cells first occurs. Antibodies against PE‐CAM‐1, TIE‐2 and SM‐α‐actin reveal that embryos homozygous for the qkk2 allele have defective yolk sac vascular remodeling and abnormal vessels in the embryo proper at midgestation, coinciding with the timing of embryonic death. However, these mutants exhibit normal expression of Nkx2.5 and α‐sarcomeric actin, indicating that cardiac muscle differentiation was normal. Further, they had normal embryonic heart rates in culture, suggesting that cardiac function was not compromised at this stage of embryonic development. Together, these results suggest that quaking plays an essential role in vascular development and that the blood vessel defects are the cause of embryonic death. genesis 32:218–230, 2002. © 2002 Wiley‐Liss, Inc.
Middle/Late Cambrian intracontinental rifting in the central West Sudetes, NE Bohemian Massif (Czech Republic): geochemistry and petrogenesis of the bimodal metavolcanic rocks
Authors: Dostal Jaroslav , Patočka František , Pin Christian
Published: August 2002

The Early Palaeozoic East Krkonoše Complex (EKC) situated in the central West Sudetes, NE Bohemian Massif, is a volcano‐sedimentary suite containing abundant mafic and felsic volcanics metamorphosed to greenschist facies.

The trace element distribution patterns and Nd isotope signatures (ENd500 = + 3.1 to + 6.6) of the metabasites (metabasalts) indicate that they may be related to a rising mantle diapir associated with intracontinental rifting. At the early stage, limited melting of an upwelling asthenosphere produced alkali basalts and enriched tholeiites which compositionally resemble oceanic island basalts. A later stage of rifting with larger degrees of melting at shallower depths generated tholeiitic basalts with E‐MORB to N‐MORB characteristics.

The values of (87Sr/86Sr)i = 0.706 and ENd500 = − 5 ±1 of the porphyroids (metarhyolites) as well as the lack of rocks with intermediate compositions suggest that the felsic rocks were formed by a partial melting event of continental crust triggered by mantle melts.

The geochemistry of the EKC bimodal metavolcanics and their association with abundant terrigenous metasediments suggest that the felsic–mafic volcanic suite was generated during intracontinental rifting. This process, widespread in Western and Central Europe during the Early Palaeozoic, is evidence of large‐scale fragmentation of the northern margin of the Gondwana supercontinent. Copyright © 2001 John Wiley & Sons, Ltd.
Four subtypes of protease‐activated receptors, co‐expressed in rat astrocytes, evoke different physiological signaling
Authors: Wang Hong , Ubl Joachim J. , Reiser Georg
Published: August 2002

Protease‐activated receptors (PARs) are newly identified members of the superfamily of G‐protein‐coupled receptors that initiate cell signaling by the proteolytic activity of extracellular serine proteases. Certain proteases are believed to be involved in development and repair processes and most likely regulate multiple functions of the CNS by activating PARs. Three members of this family (PAR‐1, PAR‐3, and PAR‐4) are considered thrombin receptors, whereas PAR‐2 is activated by trypsin. In the present study, using reverse transcription‐polymerase chain reaction (RT‐PCR), immunocytochemistry, and Ca2+ mobilization studies, we demonstrate that PAR‐1, PAR‐2, PAR‐3, and PAR‐4 are functionally co‐expressed in cultured rat astrocytes. Short‐term stimulation of astrocytes with thrombin, trypsin, and peptides corresponding to the tethered ligand domains of PAR‐1, PAR‐2, PAR‐3, and PAR‐4 induced a transient rise of [Ca2+]i in cultured astrocytes. In studying calcium signaling, based on receptor desensitization, and using an antagonist of thrombin receptor PAR‐1, we provide evidence that the thrombin‐induced [Ca2+]i response in astrocytes in addition to PAR‐1 stimulation, involves also stimulation of PAR‐3 and PAR‐4. Trypsin, in addition to PAR‐2, can also activate PAR‐1 and PAR‐4. Furthermore we find that activation of PAR‐1, and PAR‐2 induces proliferation of astrocytes while PAR‐4 activation exerts toxic effects. This study is the first to show that (1) cultured astrocytes functionally express PAR‐3 and PAR‐4 together with PAR‐1 and PAR‐2; (2) PAR‐3‐activating peptide (TFRGAP) is effective in eliciting Ca2+ signaling; and (3) activation of different PARs leads to distinct downstream effects. GLIA 37:53–63, 2002. © 2002 Wiley‐Liss, Inc.
Identification of Golli and myelin basic proteins in human brain during early development
Authors: Tosic M. , Rakic S. , Matthieu J.‐M. , Zecevic N.
Published: August 2002

The myelin basic protein gene (Mbp) encodes for the major myelin structural proteins and it is included in the Golli–Mbp gene complex. Previously, we observed MBP‐like proteins in the human central nervous system (CNS) at developmental stages preceding myelination. In an effort to distinguish between Golli (HOG5 and HOG7) and MBP mRNAs and to determine their spatiotemporal distribution, we performed in situ hybridization using two human Golli specific probes: one corresponding to exon 5a absent from all MBP transcripts, and the other corresponding to exon 5c specific for HOG5. HOG7 transcript was observed first, in 5 gestational week‐old embryos, whereas both Golli transcripts were detected at 6–7 weeks gestation in the proliferative zones of the entire CNS. Golli proteins immunoreactivity was observed in microglia and early neurons of the developing telencephalon. During midgestation (17–22 weeks gestation), at the onset of myelination, MBP and Golli mRNAs were observed in the telencephalic subventricular zone and occasionally in the future cerebral cortex. Developmental expression of the human Golli–Mbp indicates that the two Golli proteins have different onset of expression, distribution and possibly function. These results support the hypothesis that at least one of them, HOG7, may be involved in the regulation of early neurogenesis, while both may have additional, still undefined function at the onset of myelination. GLIA 37:219–228, 2002. © 2002 Wiley‐Liss, Inc.
Reactive microglia in dysmyelination and demyelination
Authors: Zhang Su‐Chun , Goetz Brian D. , Carré Jean‐Luc , Duncan Ian D.
Published: August 2002

The relationship between microglial activation and dysmyelination/demyelination was analyzed in a long‐lived myelin mutant, the Long Evans shaker (les) rat, which exhibits early dysmyelination and a later loss of abnormal myelin sheaths. A microglial reaction characterized by progressive morphological transformation and increasing cell density was localized exclusively to white matter during postnatal 2–4 weeks, suggesting a microglial response to dysmyelination and oligodendroglial pathology. A further microglial reaction as marked by microglial expression of MHC II and a concomitant expression in the brain and spinal cord of mRNA for interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), and inducible nitric oxide synthase (iNOS) began around 4 weeks when the remaining myelin was lost. Ultrastructurally, activated microglia ingested numerous myelin figures, suggestive of active phagocytosis. Thus, this study indicates that microglial reaction is graded in chronic neurological disorders and suggests that MHC II expression marks a functional change of activated microglia. GLIA 34:101–109, 2001. © 2001 Wiley‐Liss, Inc.
Rapid morphological changes in astrocytes are accompanied by redistribution but not by quantitative changes of cytoskeletal proteins
Authors: Safavi‐Abbasi Sam , Wolff Joachim R. , Missler Markus
Published: August 2002

Astrocytes have the potential to acquire very different morphologies, depending on their regional location in the CNS and on their functional interactions with other cell types. Morphological changes between a flat or a fibroblast‐like and a stellate or process‐bearing appearance, and vice versa, can occur rapidly, but very little is known as to whether morphological transformations are based on quantitative changes of cytoskeletal proteins in microfilaments, intermediate filaments, and/or microtubules. Using a cell culture of selective type 1 astrocytes, we compared the distribution and protein amounts of a number of cytoskeletal proteins both during primary process growth induced by specific media conditions and after secondary transformations induced by dBcAMP. Our data presented in this report support the idea that astrocytes can undergo dramatic changes in their morphology requiring subcellular redistribution of most cytoskeletal proteins but no quantitative modifications of the amount of the respective proteins. After pharmacological treatment with lysophosphatic acid and genistein we show that astrocytes can acquire intermediate morphologies reminiscent of both fibroblast and stellate‐like cells. These experiments demonstrate that the recently described RhoA‐mediated signaling cascade between the cell surface and cytoskeletal proteins is only one of several signaling pathways acting on the astrocytic cytoskeleton. GLIA 36:102–115, 2001. © 2001 Wiley‐Liss, Inc.
The characterisation and impact of ‘fluctuating’ cognition in dementia with Lewy bodies and Alzheimer's disease
Authors: Ballard Clive , Walker Matthew , O'Brien John , Rowan Elise , McKeith Ian
Published: August 2002

Background

Case reports and clinical observations suggest that fluctuating cognition (FC) is common in all the major dementias, particularly dementia with Lewy bodies (DLB) where it is one of three core clinical diagnostic features. The purpose of this study was to characterise FC and determine its impact upon activities of daily living.

Methods

Forty matched subjects (15 DLB, 15 AD, 10 elderly controls) were assessed using the activities of daily living scale (ADLD), the cognitive drug research (CDR) computerised neuropsychological test battery and a semi‐standardised assessment of FC. The CDR battery was completed three times across a 1‐week period, to evaluate variability in attention, visuospatial ability, working memory and delayed recall.

Results

There was a strong positive correlation between clinical FC scores and total mean ADLD. Measures of cognitive variability also demonstrated strong significant correlations with independent clinical severity ratings of FC across several cognitive domains. These associations were most powerful between attentional measures and clinical FC ratings.

Conclusions

Although attention is the cognitive domain which fluctuates most markedly, other cognitive domains are also affected. FC also has a significant independent impact on activities of daily living. Copyright © 2001 John Wiley & Sons, Ltd
The systematic assessment of depressed elderly primary care patients
Authors: Raue Patrick J. , Alexopoulos George S. , Bruce Martha L. , Klimstra Sibel , Mulsant Benoit H. , Gallo Joseph J. ,   the PROSPECT Study Group
Published: August 2002

Studies of the primary care treatment of depressed elderly patients are constrained by limited time and space and by subject burden. Research assessments must balance these constraints with the need for obtaining clinically meaningful information. Due to the wide‐ranging impact of depression, assessments should also focus on suicidality, hopelessness, substance abuse, anxiety, cognitive functioning, medical comorbidity, functional disability, social support, personality, service use and satisfaction with services. This paper describes considerations concerning the assessment selection process for primary care studies, using the PROSPECT (Prevention of Suicide in Primary Care Elderly: Collaborative Trial) study as an example. Strategies are discussed for ensuring that data are complete, valid and reliable. Copyright © 2001 John Wiley & Sons, Ltd.
Very early‐onset familial Alzheimer's disease: a novel presenilin 1 mutation
Authors: Goldman Jill S. , Reed Bruce , Gearhart Rosalie , Kramer Joel H. , Miller Bruce L.
Published: August 2002

Background

Early‐onset familial Alzheimer's disease (EOFAD) is linked to mutations in three autosomal dominant genes: PS1, PS2 and APP. The clinical presentation and age of onset of mutations is variable.

Objectives

The aim of this report is to describe a novel PS1 mutation believed to be causal for a very early onset of AD.

Methods

This is a case history using information from medical records, relative interviews and genetic testing results to describe the pre‐clinical prodrome and clinical course of a patient with EOFAD.

Results

A previously undescribed G206V mutation in PS1 was found in the proband.

Conclusion

The G206V mutation in PS1 is probably causal of a case of EOFAD with significant premorbid features. Copyright © 2002 John Wiley & Sons, Ltd.
Comparison of neuronal and hemodynamic measures of the brain response to visual stimulation: An optical imaging study
Authors: Gratton Gabriele , Goodman‐Wood Marsha Ruth , Fabiani Monica
Published: August 2002

The noninvasive mapping of hemodynamic brain activity has led to significant advances in neuroimaging. This approach is based in part on the assumption that hemodynamic changes are proportional to (and therefore constitute a linear measure of) neuronal activity. We report a study investigating the quantitative relationship between neuronal and hemodynamic measures. This study exploited the fact that optical imaging methods can simultaneously provide noninvasive measures of neuronal and hemodynamic activity from the same region of the brain. We manipulated visual stimulation frequency and measured responses from the medial occipital area of 8 young adults. The results were consistent with a model postulating a linear relationship between the neuronal activity integrated over time and the amplitude of the hemodynamic response. The hemodynamic response colocalized with the neuronal response. These data support the use of quantitative neuroimaging methods to infer the intensity and localization of neuronal activity in occipital areas. Hum. Brain Mapping 13:13–25, 2001. © 2001 Wiley‐Liss, Inc.
fMRI investigation of sentence comprehension by eye and by ear: Modality fingerprints on cognitive processes
Authors: Michael Erica B. , Keller Timothy A. , Carpenter Patricia A. , Just Marcel Adam
Published: August 2002

The neural substrate underlying reading vs. listening comprehension of sentences was compared using fMRI. One way in which this issue was addressed was by comparing the patterns of activation particularly in cortical association areas that classically are implicated in language processing. The precise locations of the activation differed between the two modalities. In the left inferior frontal gyrus (Broca's area), the activation associated with listening was more anterior and inferior than the activation associated with reading, suggesting more semantic processing during listening comprehension. In the left posterior superior and middle temporal region (roughly, Wernicke's area), the activation for listening was closer to primary auditory cortex (more anterior and somewhat more lateral) than the activation for reading. In several regions, the activation was much more left lateralized for reading than for listening. In addition to differences in the location of the activation, there were also differences in the total amount of activation in the two modalities in several regions. A second way in which the modality comparison was addressed was by examining how the neural systems responded to comprehension workload in the two modalities by systematically varying the structural complexity of the sentences to be processed. Here, the distribution of the workload increase associated with the processing of additional structural complexity was very similar across the two input modalities. The results suggest a number of subtle differences in the cognitive processing underlying listening vs. reading comprehension. Hum. Brain Mapping 13:239–252, 2001. © 2001 Wiley‐Liss, Inc.
Formation and x‐ray crystallographic analysis of a 1,2λ5‐oxaphosphol‐5(2H)‐one
Authors: Kano Naokazu , Xing Jia‐Hua , Kikuchi Azusa , Kawashima Takayuki
Published: August 2002

Reaction of an iminophosphorane 2 bearing the Martin ligand with dimethyl acetylenedicarboxylate, followed by a ring opening reaction of a [2+2]‐cycloadduct between them, gave the corresponding α‐iminoalkylidenephosphorane 3, which was hydrolyzed to afford 1,2λ5‐oxaphosphol‐5(2H)‐one 4. The structure of the novel five‐membered ring compound 4 was established by X‐ray crystallographic analysis. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:282–286, 2001
Reaction of (E)‐bis(2,4,6‐tri‐tert‐butylphenyl)diphosphene with tetrachloro‐o‐benzoquinone
Authors: Freytag Matthias , Jones Peter G. , Schmutzler Reinhard , Yoshifuji Masaaki
Published: August 2002

The reactions of (E)‐bis(2,4,6‐tri‐tert‐butylphenyl)diphosphene with tetrachloro‐o‐benzoquinone gave two products of interest, a spirophosphorane and a 1,3,2‐dioxaphospholane, indicating cleavage of the P=P bond. The structures were determined by X‐ray crystallographic analyses. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:300–308, 2001
Defining international education
Authors: Moran Hansen Holly
Published: August 2002

Americans can learn much about U.S. culture by studying and visiting other cultures. The study of other cultures can also promote tolerance and help avert acts of international aggression.
Alcohol abuse and economic conditions: Evidence from repeated cross‐sections of individual‐level data
Authors: Dee Thomas S.
Published: August 2002

This study presents novel evidence on the relationship between macroeconomic conditions and patterns of alcohol consumption. Prior research has suggested that alcohol abuse varies procyclically, implying that income effects dominate any drinking patterns related to the opportunity cost of time or the psychological stress of recessions. However, those inferences have been based either on aggregate measures of consumption volume or possibly confounded cross‐sectional identification strategies. This study examines these issues by evaluating detailed consumption data from the more than 700 000 respondents who participated in the Center for Disease Control and Prevention's Behavioral Risk Factor Surveillance System (BRFSS) surveys over the 1984–1995 period. The results provide robust evidence that the prevalence of binge drinking is strongly countercyclical. Furthermore, even among those who remain employed, binge drinking increased substantially during economic downturns. This combination of results suggests that recession‐induced increases in the prevalence of binge drinking do not simply reflect an increased availability of leisure and may instead reflect the influence of economic stress. Copyright © 2001 John Wiley & Sons, Ltd.
Testing the convergent validity of the contingent valuation and travel cost methods in valuing the benefits of health care
Authors: Clarke Philip M.
Published: August 2002

In this study, the convergent validity of the contingent valuation method (CVM) and travel cost method (TCM) is tested by comparing estimates of the willingness to pay (WTP) for improving access to mammographic screening in rural areas of Australia. It is based on a telephone survey of 458 women in 19 towns, in which they were asked about their recent screening behaviour and their WTP to have a mobile screening unit visit their nearest town. After eliminating missing data and other non‐usable responses the contingent valuation experiment and travel cost model were based on information from 372 and 319 women, respectively. Estimates of the maximum WTP for the use of mobile screening units were derived using both methods and compared. The highest mean WTP estimated using the TCM was $83.10 (95% C.I. $99.06–$68.53), which is significantly less than the estimate of $148.09 ($131.13–$166.60) using the CVM. This could be due to the CVM estimates also reflecting non‐use values such as altruism, or a range of potential biases that are known to affect both methods. Further tests of validity are required in order to gain a greater understanding of the relationship between these two methods of estimating WTP. Copyright © 2001 John Wiley & Sons, Ltd.
Oral squamous cell carcinoma of the mandibular region: A survival study
Authors: De Vicente Juan Carlos , Recio Oliver Rodríguez , Pendás Santiago Llorente , López‐Arranz Juan Sebastián
Published: August 2002

Background

Oral squamous cell carcinomas (SCC) of the mandibular region present the lowest survival rates of the whole oral cavity. The purpose of this analysis was to evaluate the prognostic significance of several diagnostic and therapeutic variables in the survival rates of these carcinomas.

Methods

Forty‐nine patients with oral cancers were treated by primary site surgery, involving mandibular resection in all cases. Thirty‐one patients underwent postoperative adjuvant radiotherapy.

Results

Overall mean survival time and 5‐year survival rate were 56.5 months and 44%, respectively. Patients in stages III and IV showed a statistically significant (p= .01) lower survival rate than those in stage II, and positive surgical margins had an adverse effect on survival (p= .03). No differences were found between patients treated by marginal or segmental mandibulectomy.

Conclusions

Among the prognostic predictors studied, only the status of the surgical resection margin (odds ratio, 5.7) and tumor stage (III and IV vs II showed odds ratios of 2.1 and 3.6, respectively) affected the prognosis for SCC of the mandibular region. Tumor site was not associated with prognosis but was related with the probability that surgical margins were involved. © 2001 John Wiley & Sons, Inc. Head Neck 23: 536–543, 2001.
Reciprocal connections between the entorhinal cortex and hippocampal fields CA1 and the subiculum are in register with the projections from CA1 to the subiculum
Authors: Naber Pieterke A. , Lopes da Silva Fernando H. , Witter Menno P.
Published: August 2002

The topology of the connections between the entorhinal cortex (EC), area CA1, and the subiculum is characterized by selective and restricted origin and termination along the transverse or proximodistal axis of CA1 and the subiculum. In the present study, we analyzed whether neurons in CA1 and the subiculum that receive EC projections are interconnected and give rise to return projections to EC, such that they terminate deep in the area of origin of the EC‐to‐CA1/subiculum projections. Both for the lateral and medial subdivision of EC, the projections to CA1/subiculum, as well as the projections from CA1 to the subiculum and back to EC, are rather divergent. Interestingly, we only rarely observed evidence for the presence of “reentry loops,” i.e., cells in layer III of EC giving rise to projections to interconnected neurons in CA1 and the subiculum, while the targeted CA1 neurons also projected back to the deep layers of the area of origin of the pathway in EC. We conclude that although fibers originating from a restricted part of EC distribute extensively in a divergent way along the longitudinal axis of CA1 and the subiculum, only restricted portions of the latter two areas, receiving inputs from the same entorhinal area, are interconnected. Moreover, only a small percentage of the CA1 neurons that project to the correspondingly innervated subicular neurons give rise to projections that return to the deep layers of the originating part of EC. The present findings are taken to indicate that the EC‐hippocampal circuitry functionally comprises many parallel‐organized specific “reentry loops.” Hippocampus 2001;11:99–104. © 2001 Wiley‐Liss, Inc.
Evaporation heat transfer of falling water film on a horizontal tube bundle
Authors: Liu Zhen‐Hua , Zhu Qun‐Zhi , Chen Yu‐Ming
Published: August 2002

A numerical simulation and experimental study were carried out for evaporation heat transfer of a falling water film on a smooth horizontal tube bundle evaporator. A laminar model and a turbulence model were respectively adopted to calculate the heat transfer coefficients of falling water film on horizontal heated tubes. The calculation zone on the heated tube was divided into the top stagnation zone and the lateral free film zone. The initial boundary conditions for the free film zone were determined from the calculated results of the stagnation zone. The modified wall function method was used for the turbulent flow. Comparisons between the experimental data and the numerical solutions by use of two flow models show that the experimental data lie between the laminar model solutions and the latter turbulence model solutions and that they are closer to the latter solutions. Finally, a simple dimensionless correction based on the numerical simulations is proposed for predicting the evaporation heat transfer of falling water film for actual engineering applications. © 2001 Scripta Technica, Heat Trans Asian Res, 31(1): 42–55, 2002
Boundary shape determination of steady‐state heat‐conduction fields
Authors: Katamine Eiji , Azegami Hideyuki , Kojima Masami
Published: August 2002

In this paper, a practical method of numerical analysis for the boundary shape design of steady‐state heat‐conduction fields to control the temperature distribution to a prescribed distribution is presented. Reshaping was accomplished by the traction method proposed by one of the authors as a solution to domain optimization problems in which elliptic boundary value problems were defined. In this study, we formulated a temperature square error norm minimization problem between the prescribed distribution and the actual distribution on prescribed boundaries and theoretically derived a shape gradient function for this problem. We developed a convenient numerical method using a general‐purpose FEM program for the temperature prescribed problem. The successful results for the two‐dimensional problems of an erosion surface on a blast furnace hearth and a coolant flow passage in a wing demonstrate the validity of the presented method. © 2001 Scripta Technica, Heat Trans Asian Res, 30(3): 245–258, 2001