bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of age‐related responses to short‐term environmental variation: Time series analysis of cross‐sectional data from Taiwan, 1969 to 1990
Authors: Floyd Bruce
Published: August 2002

Cross‐sectional heights and weights collected by Taiwan’s Ministry of Education since 1964, and reported separately for Taipei and rural townships from 1969 through 1990, were used to test the hypothesis that in Taiwan the degree to which increments of change in height and weight of urban or rural boys and girls tracked each other from year to year was a function of sex and age‐related capacities to respond to common environmental forces. Five testable implications follow from this hypothesis. Results were evaluated using detrended time series derived correlations of yearly or near yearly change in sex‐specific age group height or weight means within and across regions, cross‐sectionally estimated ages of maximum change of height and weight, and evidence of response to two recessions. The hypothesis was largely supported by the available evidence. The similarities in secular change from year to year, with only a few exceptions, suggested that socioeconomic trends indirectly affected the pace of growth of children in both urban and rural Taiwan measured in the spring of the following year. The strength and age‐related pattern of these correlations were consistent with sex and age‐related capacities to respond to shared environmental factors. Evidence of lags between height and weight, found both in cross‐sectionally estimated mean ages of maximum change in height and weight and in the pattern of within sex correlations also argued for the hypothesis. The evidence further suggested that when the economy faltered briefly in Taiwan following worldwide oil crises, children’s growth was rapidly affected in an age‐dependent manner. This study bolsters the view that secular changes in growth reflect environmental quality. It suggests as well that under some circumstances, environmental change may be rapidly reflected as mean changes in height or weight of certain age groups. The intensity of the response appears to be related to the degree of improvement or deprivation, the maturationally mediated pace of growth, and probably initial energy balance. Am. J. Hum. Biol. 14:61–73, 2002. © 2002 Wiley‐Liss, Inc.
Information content of female copulation calls in yellow baboons
Authors: Semple Stuart , McComb Karen , Alberts Susan , Altmann Jeanne
Published: August 2002

In a wide variety of animal species, females produce vocalizations just before, during, or immediately after copulation. Observational and experimental evidence indicates that these copulation calls are sexually selected traits, functioning to promote competition between males for access to the calling female. In this paper, we present an acoustic analysis of variation in the form of copulation calls of female yellow baboons,Papio cynocephalus cynocephalus. In particular, we examine whether information about three factors—the calling female’s reproductive state, the occurrence or absence of ejaculation, and the dominance rank of the mating male—is encoded in call structure and hence is potentially available to male receivers attending to the signal. Although several features of copulation calls were correlated with each of these factors, when all three were included in multiple regressions only reproductive state and rank of the mating male had independent effects on call form. These findings indicate that female copulation calls in this species signal information about the proximity to ovulation of the calling female and also the relative competitive strength of her mating partner. Am. J. Primatol. 56:43–56, 2002. © 2002 Wiley‐Liss, Inc.
Lack of congruence between morphological and molecular data in reconstructing the phylogeny of the galagonidae
Authors: Masters Judith C. , Brothers Denis J.
Published: August 2002

Published cladistic reconstructions of galagonid phylogeny based on morphological, behavioral, and genetic data have had few elements in common. A recent molecular study indicated that 2 of the 3 generic groupings derived from morphological data were not consistent with tree topologies constructed from the analysis of mitochondrial DNA sequences. In this study, we compiled and analyzed a data set based on craniodental morphology in 13 galagonid and 8 outgroup taxa, comprising 3 dwarf‐lemur and 5 loris species, and subjected it to cladistic analysis. Our aim was not only to generate a new phylogenetic hypothesis based on these data, but also to investigate the conditions under which congruence could be achieved between these results and those obtained previously. The data set was found to be highly sensitive to the choice of outgroup, with the lorises showing high interspecific variability in cranial structure. Congruence between the craniodental and molecular trees could be achieved only if Arctocebus was used as the outgroup and two characters were preferentially weighted. Further progress in the reconstruction of galagonid phylogeny will require seeking consensus in a variety of other data sets, including postcranial morphology, behavior, and additional gene sequences. The effect of different outgroups on molecular analysis needs attention. Am J Phys Anthropol 117:79–93, 2002. © 2002 Wiley‐Liss, Inc.
Combined effect of age and severity on the risk of dementia in Parkinson's disease
Authors: Levy Gilberto , Schupf Nicole , Tang Ming‐Xin , Cote Lucien J. , Louis Elan D. , Mejia Helen , Stern Yaakov , Marder Karen
Published: August 2002

Age and severity of extrapyramidal signs have been consistently associated with incident dementia in Parkinson's disease. We evaluated the separate and combined effects of age and severity of extrapyramidal signs on the risk of incident dementia in Parkinson's disease in the setting of a population‐based prospective cohort study. Age and the total Unified Parkinson's Disease Rating Scale motor score at baseline evaluation were dichotomized at the median. Four groups of Parkinson's disease patients were defined: younger age/low severity (reference), younger age/high severity, older age/low severity, and older age/high severity. Risk ratios for incident dementia were calculated with Cox proportional hazards models controlling for gender, education, ethnicity, and duration of Parkinson's disease. Of 180 patients, 52 (28.9%) became demented during a mean follow‐up period of 3.6 ± 2.2 years. The median age at baseline of the Parkinson's disease patients was 71.8 years (range, 38.5–95.9 years), and the median total Unified Parkinson's Disease Rating Scale motor score was 24 (range, 2–65). The group with older age/high severity had a significantly increased risk of incident dementia (relative risk, 9.7; 95% confidence interval, 3.9–24.4) compared with the group with younger age/low severity (reference), whereas the groups with older age/low severity (relative risk, 1.6; 95% confidence interval, 0.5–4.8) and younger age/high severity (relative risk, 1.2; 95% confidence interval, 0.5–3.2) did not. These findings suggest that the increased risk of incident dementia in Parkinson's disease associated with age and severity of extrapyramidal signs is related primarily to their combined effect rather than separate effects.
Preparation and characterization of organic–inorganic hybrids and coating films from 3‐methacryloxypropylpolysilsesquioxane
Authors: Gunji Takahiro , Makabe Yoshie , Takamura Norihiro , Abe Yoshimoto
Published: August 2002

3‐Methacryloxypropylpolysilsesquioxane (MA‐PS) was prepared by acid‐ or base‐catalyzed hydrolytic polycondensation of 3‐methacryloxypropyltrimethoxysilane (MAS). MA‐PS coating film was prepared by dip‐coating on organic, metal and inorganic substrates, including poly(ethylene terephthalate), aluminum, stainless steel, and glass. The coating films on poly(ethylene terephthalate) and glass showed high adhesive strength. The hardness of coating films increased with increasing heat treatment temperature, whereas they decreased with increasing H2O/MAS molar ratio. The refractive index of coating films increased with increasing heat treatment temperature. In addition, flat and transparent free‐standing films (0.24–0.27 mm thickness) were prepared from MA‐PS that were crack‐free after heat treatment at 1000 °C. Copyright © 2001 John Wiley & Sons, Ltd.
Tissue accumulation and distribution of arsenic compounds in three marine fish species: relationship to trophic position
Authors: Kirby J. , Maher W.
Published: August 2002

In this study the accumulation and distribution of arsenic compounds in marine fish species in relation to their trophic position was investigated. Arsenic compounds were measured in eight tissues of mullet Mugil cephalus (detritivore), luderick Girella tricuspidata (herbivore) and tailor Pomatomus saltatrix (carnivore) by high performance liquid chromatography–inductively coupled plasma‐mass spectrometry. The majority of arsenic in tailor tissues, the pelagic carnivore, was present as arsenobetaine (86–94%). Mullet and luderick also contained high amounts of arsenobetaine in all tissues (62–98% and 59–100% respectively) except the intestines (20% and 24% respectively). Appreciable amounts of dimethylarsinic acid (1–39%), arsenate (2–38%), arsenite (1–9%) and trimethylarsine oxide (2–8%) were identified in mullet and luderick tissues. Small amounts of arsenocholine (1–3%), methylarsonic acid (1–3%) and tetramethylarsonium ion (1–2%) were found in some tissues of all three species. A phosphate arsenoriboside was identified in mullet intestine (4%) and from all tissues of luderick (1–6%) except muscle. Pelagic carnivore fish species are exposed mainly to arsenobetaine through their diet and accumulate the majority of arsenic in tissues as this compound. Detritivore and herbivore fish species also accumulate arsenobetaine from their diet, with quantities of other inorganic and organic arsenic compounds. These compounds may result from ingestion of food and sediment, degradation products (e.g. arsenobetaine to trimethylarsine oxide; arsenoribosides to dimethylarsinic acid), conversion (e.g. arsenate to dimethylarsinic acid and trimethylarsine oxide by bacterial action in digestive tissues) and/or in situ enzymatic activity in liver tissue. Copyright © 2001 John Wiley & Sons, Ltd.
A novel latent initiator for cationic polymerizations of epoxides: Composite catalysts containing aluminum complexes phase‐separated in epoxides
Authors: Murai S. , Fujieda S. , Hayase S.
Published: August 2002

A novel latent initiator for cationic polymerizations of epoxides heterogeneous aluminum complex/phenol initiator (HAP) is reported. Phase transitions are newly employed for realizing the latent property. The initiator consists of 4,4′‐dihydroxydiphenylsulfone and aluminum tris(alkyl acetoacetate), with the alkyl group containing more than 18 carbons. The composite initiator is phase‐separated and dispersed uniformly in epoxy resins at room temperature. When the mixture is heated to a temperature greater than 70°C, the composite initiator makes clear mixtures with epoxy resins because of the phase change in the aluminum complexes. Homogeneous epoxy resins containing these composite initiators are ready for various types of processing, including impregnation and injection. Gelation occurs rapidly at temperatures greater than 100°C. The phase change in the initiator makes it possible for the epoxy compounds to have a long storage stability at room temperature and a high curing speed at greater than 100°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1046–1053, 2002
Yielding of polymers filled with large‐diameter particles
Authors: Metzner Arthur P.
Published: August 2002

The yield stress of a polymer filled with rigid filler particles much larger than 5 μm is affected by the single‐particle debonding stress at large volume fractions of filler. This relationship holds up to a limiting modulus based on the size of the polymer chains of the binder. An elastic yield energy, or resilience, is defined. Within the limits of the yield stress equation, this yield energy is constant over a wide range of strain rates and temperatures at high volume fractions of filler. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 455–466, 2002
Synthesis of branched polyethylene by ethylene homopolymerization with a novel (α‐diimine)nickel complex in the presence of methylaluminoxane
Authors: Zhu Fangming , Xu Wei , Liu Xinxing , Lin Shangan
Published: August 2002

Branched polyethylene (PE) was prepared with a novel (α‐diimine)nickel(II) complex of 2,3‐bis(2,6‐dimethylphenyl)‐butanediimine nickel dichloride {[2,6‐(CH3)2C6H3NC(CH3)C(CH3)N2,6‐(CH3)2C6H3]NiCl2} activated by methylaluminoxane in the presence of a single ethylene monomer. The influences of various polymerization conditions, including the temperature, Al/Ni molar ratio, Ni catalyst concentration, and time, on the catalytic activity, molecular weight, degree of branching, and branch length of PE were investigated. According to gel permeation chromatography, the weight‐average molecular weights of the polymers obtained ranged from 1.7 × 105 to 6.0 × 105, with narrow molecular weight distributions of 2.0–3.5. The degree of branching in the polymers rapidly increased with the polymerization temperature increasing; this led to highly crystalline to totally amorphous polymers, but it was independent of the Al/Ni molar ratio and catalyst concentration. At polymerization temperatures greater than 20°C, the resultant PE was confirmed by 13C‐NMR to contain significant amounts of not only methyl but also ethyl, propyl, butyl, amyl, and long branches (longer than six carbons). The formation of the branches could be illustrated by the chain walking mechanism, which controlled their specific spacing and conformational arrangements with one another. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1123–1132, 2002; DOI 10.1002/app.10398
Synthesis and characterization of PMMA‐b‐PBMA block copolymers by atom transfer radical polymerization
Authors: Fernández‐García Marta , De La Fuente José Luis , Fernández‐Sanz Marina , Madruga Enrique López
Published: August 2002

The synthesis of diblock copolymers using atom transfer radical polymerization, ATRP, of n‐butyl methacrylate, BMA, and methyl methacrylate, MMA, is reported. These copolymers were prepared from 2‐bromoisobutyryl‐terminated macroinitiators of poly(MMA) and poly(BMA), using copper chloride, CuCl,/N,N,N′,N″,N″‐pentamethyldiethylenetretramine, PMDETA, as the catalyst system, at 100°C in bulk and in benzonitrile solution. The block copolymers were characterized by means of size‐exclusion chromatography, SEC, and 1H‐NMR spectroscopy. The SEC analysis of the synthesized diblock copolymers confirmed important differences in the molecular weight control depending on the reaction medium (solvent effect) and the chemical structure of the macroinitiator used. In addition, differential scanning calorimetry, (DSC) measurements were performed, showing for all the copolymers a phase separation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2683–2691, 2002
Novel polyureas having isobutenyl bis(aryl ether) moieties in the polymer main chain: Synthesis, tandem Claisen rearrangement, and thermal patterning on polymer film surface using microthermal analyzer
Authors: Yang Gang , Tokuhisa Hideo , Koyama Emiko , Matsuzono Shin‐Ichiro , Hiratani Kazuhisa
Published: August 2002

Two kinds of new polyureas 2a and 2b were synthesized by polyaddition of 1,4‐phenylene diisocyanate with 2‐{2‐[(2‐amino‐4‐methyl‐phenoxy)methyl]allyl}oxy‐5‐methyl‐aniline (diamine 1a) and 2‐{2‐[(2‐amino‐4‐tert‐butyl‐phenoxy)methyl]allyl}oxy‐5‐tert‐butyl‐aniline (diamine 1b), respectively. The isobutenyl bis(aryl ether) moiety, capable of yielding plural phenolic hydroxyls by means of tandem Claisen rearrangement (TCR), was successfully incorporated into the resulting polymer main chain. TCR at isobutenyl bis(aryl ether) moieties readily occurred by heating in the bulk state, affording phenolic hydroxy groups ortho to urea linkages. Subsequent intramolecular cyclization between the hydroxy groups and the urea groups gave the bis(2‐benzoxazolinone) derivatives, with loss of 1,4‐phenylenediamine, resulting in degradation of the polymers. At the same time, the thermal properties were investigated by TG/DTA. The degradation of these new polymers in the bulk state was shown to proceed smoothly by heating at 230°C. Using a microthermal analyzer (μTA), a preliminary study of thermal patterning on polyurea 2b film surface was carried out, and precise spot patterns were successfully processed with diameters of less than 1 μm. Two kinds of novel polyureas, containing isobutenyl bis(aryl ether) moieties ortho to the urea linkages were successfully synthesized. These results imply that these easily decomposable polymers might be used as patterning materials. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2287–2293, 2002
Short‐term effects of sea water on E‐glass/vinylester composites
Authors: Wu Lixin , Murphy Karen , Karbhari Vistasp M. , Zhang James S.
Published: August 2002

The use of ambient cured E‐glass/vinylester composites is increasingly being considered for infrastructure applications both along the shore and offshore, thereby exposing the composite to a marine aqueous environment. The use of ambient cure potentially results in incomplete polymerization and susceptibility for degradation early in life. This study characterizes the mechanical response of E‐glass/vinylester quadriaxial composites immersed in deionized water, sea water, and synthetic sea water. It is seen that there are substantial differences based on the solution type, with deionized water immersion causing the maximum drop in interlaminar shear performance and sea water causing the maximum reduction in tensile performance. The effect of cycling, simulating the tidal zone or the splash zone, is seen to be more pronounced in a resin‐dominated response. Drying of specimens, even over prolonged periods of time, is not seen to result in complete regain of performance degradation due to sorption processes. A clear competition is seen between the phenomena of moisture‐induced residual cure/postcure and physical (fiber‐matrix debonding, microcracking, plasticization) and chemical (hydrolysis) aging. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2760–2767, 2002
Effect of transesterification on the morphology and mechanical properties of a blend containing a liquid crystalline polymer
Authors: Radmard B. , Dadmun M. D.
Published: August 2002

Transesterification of polymer blends containing polyesters is often utilized to improve the interfacial adhesion and mechanical properties of a phase‐separated blend. However, in some circumstances, the transesterification can also modify the morphology (crystallinity or liquid crystallinity) of the blend components due to the disruption of the structure of a regular polymer. This, in turn, can deteriorate the mechanical properties of the blend. We present, in this article, results that correlate the extent of transesterification between a liquid crystalline polyester and polycarbonate to the change in the mechanical properties of the blend and the liquid crystallinity of the liquid crystalline polymer (LCP). The results exemplify the need to understand the role of transesterification on the morphology and mechanical properties of the blend so that the optimum processing conditions may be found. The experimental protocol can also be used as a guide to determine these optimal processing conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2583–2592, 2001
Comparison of properties of segmented copolyetheresteramides containing uniform aramid segments with commercial segmented copolymers
Authors: Niesten M. C. E. J. , Gaymans R. J.
Published: August 2002

The thermal (using differential scanning calorimetry), dynamic mechanical (using a dynamic mechanical analyzer), and mechanical properties of segmented copolyetheresteramides with aramid units of uniform length (TΦT) and poly(tetramethylene oxide) (PTMO) segments were compared to those of commercial segmented copolyetheresters (PBT–PTMO) and thermoplastic polyurethanes. The hard segments in TΦT‐containing polymers were found to crystallize almost completely, unlike the hard segments of Arnitel and Desmopan. Consequently, the glass‐transition temperature of TΦT‐containing polymers is lower and the melting temperature higher than those of Arnitel and Desmopan. Furthermore, the rubbery plateau of the TΦT‐containing polymers is temperature independent, making the service temperature range wider. In TΦT‐containing polymers a lower concentration of hard segment is needed to obtain dimensionally stable polymers with a high melting temperature. No melt phasing occurs during polymerization and therefore long PTMO segments can be used, producing very soft and elastic materials. The polymers crystallize faster than do commercial materials. The elasticity of the TΦT‐containing polymers is comparable to the elasticity of Desmopan and better than that of Arnitel. TΦT–(PTMO1000/DMT) copolymers are transparent and the solvent resistance is high. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1372–1381, 2001
Cellulose furoate. II. Characterization
Authors: Hon David N.‐S. , Yan Hui
Published: August 2002

The chemical structure of furoate moiety in cellulose furoate was confirmed by FTIR, UV spectroscopy, and NMR and X‐ray spectroscopy. Thermal property was studied by TGA and DSC. TGA results showed cellulose furoate has a very similar thermal property to cellulose. Thermograms revealed its decomposition started at about 300°C, and had a maximum rate of weight loss at about 360°C. DSC studies revealed the glass transition temperatures for cellulose furoates ranged from 207 to 230°C, depending upon the DS. Myrothecium verrucaria, Cheatomium globosum, and Aspergillus terreus were used to determine the biodegradability of cellulose furoate. Biodegradation tests showed that each glucose unit in cellulose required as least one substitution to significantly improve the antibiodegradation property. Solubility tests revealed that cellulose furoates with DS ranged from 1.09 and 2.66, prepared from the homogeneous system, are dissolvable in dioxane, DMSO, DMF, and DMAc. Specimens prepared from the heterogeneous system; only those with DS ranging from 1.09 and 1.98 are dissolvable in DMSO. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 243–252, 2001
Natural protein fibers
Authors: Feughelman Max
Published: August 2002

Alpha keratin fibers (hairs, wools, quills, and other mammalian appendages) together with fibroin fibers such as silks and spiders webs are all highly extensible fibrous proteins for which the mechanical properties are of primary importance both to the animal from which they originate and their ultimate application by man. Similarly, the collagens are highly inextensible fibrous proteins, which form the major component of mammalian skin and connecting structures such as tendons. All these fibrous proteins are biological polymers of polypeptide chains for which the mechanical and allied physical properties, such as water absorption, relate to both their macrostructure and their molecular and near‐molecular structure. Because of both their commercial application and their relatively complex structure at the molecular and near‐molecular level, interpretation of the physical properties of α‐keratin fibers represents the main component of this presentation. The mechanical properties of α‐keratin fibers are primarily related to the two components of the elongated cortical cells, the highly ordered intermediate filaments (microfibrils) which contain the α‐helices, and the matrix in which the intermediate filaments are embedded. The matrix consists of globular proteins plus water, the content of the latter being dependent on the fibers environment. The Extended Two‐Phase Model (ETPM) has been developed and results in a detailed coverage of the bulk mechanical properties of α‐helical fibers in terms of their known molecular and near‐molecular structure. The inextensible protein fibers, the collagens and fibroins, are also briefly discussed in terms of the relationship between mechanical properties and the structure of these fibers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 489–507, 2002
Transfer of marine organisms: a challenge to the conservation of coastal biocoenoses
Authors: Occhipinti Ambrogi A.
Published: August 2002

1. The global transfer of species across the world's oceans is an increasing threat to the biodiversity of the sea and particularly of coastal areas: the magnitude of this peculiar aspect of global change and the significance of its effects on ecosystems are currently debated.

2. The paper addresses, with reference to the Mediterranean situation, the main research needs in coastal ecosystem conservation, such as the availability of baseline assessment of native and non‐indigenous species (including biogeography, taxonomy and historical records). Studies on the transfer mechanisms and on the predictability of successful settlement by alien species are also important.

3. Finally, management actions applicable to conservation issues are mentioned and discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Neuromuscular compartments and fiber‐type regionalization in the human inferior pharyngeal constrictor muscle
Authors: Mu Liancai , Sanders Ira
Published: August 2002

The inferior pharyngeal constrictor (IPC) muscle functions during swallowing, respiration, and vocalization. The most‐caudal portion of the IPC is believed to be part of the functional upper esophageal sphincter (UES). We hypothesized that the caudal fibers of the human IPC may have enzyme‐histochemical characteristics similar to those of the cricopharyngeus muscle, a major component of the UES. In this study, human IPC muscles obtained from autopsy were studied using Sihler's stain to examine innervation patterns, and using myofibrillar ATPase, NADH tetrazolium reductase (NADH‐TR), and succinic dehydrogenase (SDH) techniques to investigate the distribution and oxidative capacity of the slow‐ (type I) and fast‐ (type II) twitch fibers in the muscle. The results showed that the human IPC consists of at least two neuromuscular compartments (NMCs): rostral and caudal. Each of the NMCs was innervated by a separate nerve branch derived from the pharyngeal branch of the vagus nerve. The rostral NMC is faster (39% type I, 61% type II) than the caudal NMC (70% type I, 30% type II). In addition, two histochemically‐delineated fiber layers were identified in the human IPC: a slow inner layer (SIL) with predominantly type I fibers (66%), and a fast outer layer (FOL) with predominantly type II fibers (62%) (P < 0.01). However, the dimensions of both fiber layers and proportions of the muscle fiber types varied with the NMCs. Specifically, the ratio of the thickness of the SIL to FOL was ∼2:1 for the caudal NMC and ∼1:2 for the rostral NMC, respectively. In the SIL the type I fibers accounted for 84% for the caudal NMC and 69% and 44% for the lower and upper portions of the rostral NMC. In contrast, the type II fibers in the FOL accounted for 46% for the caudal NMC and 67% and 74% for the lower and upper portions of the rostral NMC, respectively (P < 0.01). The caudal NMC of the IPC shared histochemical characteristics with the cricopharyngeus muscle, in that it contained predominantly slow oxidative fibers. Overall, the caudal NMC and the SIL in the IPC had high NADH‐TR and SDH activities. However, different patterns of oxidative enzyme activity were identified in both type I and type II fibers. This study provided histochemical evidence for the concept that the caudal NMC within the IPC contributes to the functional UES. In addition, the two histochemically‐defined fiber layers in the IPC may be a specialized adaptation in humans to enable different upper‐airway functions during respiration, swallowing, and speech. Anat Rec 264:367–377, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of diethylstilbestrol‐induced hypospadias in female mice
Authors: Miyagawa Shinichi , Buchanan David L. , Sato Tomomi , Ohta Yasuhiko , Nishina Yukio , Iguchi Taisen
Published: August 2002

The urethral duct and vagina are formed from the urogenital sinus (UGS) during the early neonatal period in mice. Neonatal estrogen exposure results in hypospadias, or the malpositioning of vaginal and urethral openings, with wide cleft clitoris. We sought to characterize diethylstilbestrol (DES) influence on UGS morphogenesis and hypospadias formation. Newborn (day 0) and 1–4‐day‐old female mice (ICR/Jcl) were given (s.c.) oil or 3.0 μg DES. Animals were killed 24 hr later; then hypospadias formation and epithelial apoptosis and proliferation within the developing UGS were assessed. DES did not alter normal UGS morphogenesis by day 1, in comparison with controls. However, hypospadias formation was observed in DES‐treated mice by day 3. In these mice, the distal dorsal urethral duct appeared to fuse with and open into the lower vaginal solid cord region. Further, DES treatment produced a gradual significant increase in dorsal urethral epithelial apoptosis (P < 0.05) just prior to and during fusion and hypospadias formation. DES‐induced urethral epithelial and sinus cord proliferation appeared significantly increased (P < 0.05) and unchanged, respectively, just prior to fusion. By day 5, DES‐treated mice exhibited wide cleft clitoris. In addition, if DES was given on day 3 or 5, a gradual, distinct caudal shift in the vaginal‐urethral junction was observed compared to mice treated on days 0–2. Although hypospadias was not induced when neonates were given DES on day 7, these mice continued to display early vaginal opening. Dose‐response analysis indicated that 0.03 μg DES for 5 days is the lowest known critical dose for hypospadias induction. We have shown for the first time that DES‐induced hypospadias onset may primarily be the result of changes in developing dorsal urethral epithelial cell apoptotic and proliferative activity, and that the location of DES‐induced hypospadias formation is dependent on age at time of exposure. Anat Rec 266:43–50, 2002. © 2002 Wiley‐Liss, Inc.
Regional changes in the contralateral “healthy” hemisphere after ischemic lesions evaluated by quantitative T2 parametric maps
Authors: Sbarbati Andrea , Reggiani Angelo , Nicolato Elena , Arban Roberto , Lunati Ernesto , Osculati Francesco
Published: August 2002

Modifications in the contralateral “healthy” hemisphere in a population of rats bearing cortical infarction were studied in vivo by magnetic resonance imaging (MRI) with the aim to investigate whether cerebral areas not directly involved in the lesion react at the presence of an ischemic lesion. The study was performed in rats in which a transtemporal approach was adopted to occlude the right middle cerebral artery (MCA). For MRI, the animals were examined at 4.7 Tesla and quantitative T2 parametric images were obtained by a multiecho sequence. Healthy rats and sham‐operated animals were used as control groups. The quantitative T2 parametric images showed that in the first week after the ischemia a significant increase in the mean T2 was seen in the lesioned parietal cortex, compared to the corresponding region of healthy rats (106 msec vs. 68 msec, P < 0.001). The contralateral “healthy” hemisphere showed T2 mean values not significantly different from the corresponding hemisphere of healthy rats (71 msec vs. 70 msec). However, a statistically significant increase in the T2 values was evident in the hypothalamic region (74 msec vs. 66 msec, P < 0.001). In rats examined 1 month after the ischemia, the T2 values of the hypothalamus were lower than those observed one week after ischemia (69 msec) but remained higher than in controls. The present study demonstrates that after a cerebral ischemia areas of secondary involvement distant from the lesion are present and can be studied in vivo by quantitative MRI. Anat Rec 266:118–122, 2002. © 2002 Wiley‐Liss, Inc.
Maps of the Brain
Authors: Toga Arthur W. , Thompson Paul M.
Published: August 2002

We review recent developments in brain mapping and computational anatomy that have greatly expanded our ability to analyze brain structure and function. The enormous diversity of brain maps and imaging methods has spurred the development of population‐based digital brain atlases. These atlases store information on how the brain varies across age and gender, across time, in health and disease, and in large human populations. We describe how brain atlases, and the computational tools that align new datasets with them, facilitate comparison of brain data across experiments, laboratories, and from different imaging devices. The major methods are presented for the construction of probabilistic atlases, which store information on anatomic and functional variability in a population. Algorithms are reviewed that create composite brain maps and atlases based on multiple subjects. We show that group patterns of cortical organization, asymmetry, and disease‐specific trends can be resolved that may not be apparent in individual brain maps. Finally, we describe the creation of four‐dimensional (4D) maps that store information on the dynamics of brain change in development and disease. Digital atlases that correlate these maps show considerable promise in identifying general patterns of structural and functional variation in human populations, and how these features depend on demographic, genetic, cognitive, and clinical parameters. Anat Rec (New Anat) 265:37–53, 2001. © 2001 Wiley‐Liss, Inc.
Tissue engineering in plastic reconstructive surgery
Authors: Walgenbach Klaus‐J. , Voigt Mathias , Riabikhin Artiom W. , Andree Christoph , Schaefer Dirk J. , Galla Thomas J. , Stark G. Björn
Published: August 2002

Tissue engineering (TE) is a new interdisciplinary field of applied research combining engineering and biosciences together with clinical application, mainly in surgical specialities, to develop living substitutes for tissues and organs. Tissue engineering approaches can be categorized into substitutive approaches, where the aim is the ex vivo construction of a living tissue or organ similar to a transplant, vs. histioconductive or histioinductive concepts in vivo. The main successful approaches in developing tissue substitutes to date have been progresses in the understanding of cell–cell interactions, the selection of appropriate matrices (cell–matrix interaction) and chemical signalling (cytokines, growth factors) for stimulation of cell proliferation and migration within a tissue‐engineered construct. So far virtually all mammalian cells can be cultured under specific culture conditions and in tissue specific matrices. Future progress in cell biology may permit the use of pluripotent stem cells for TE. The blueprint for tissue differentiation is the genome: for this it is reasonable to combine tissue engineering with gene therapy. The key to the progress of tissue engineering is an understanding between basic scientists, biochemical engineers, clinicians, and industry. Anat Rec 263:372–378, 2001. © 2001 Wiley‐Liss, Inc.
Erratum
Authors: Yamamoto Daisuke
Published: August 2002

The reproduction quality of figure 1 from the article, “Pathology of the adult central nervous system induced by genetic inhibition of programmed cell death in Drosophila pupae” by Kazue Usui‐Aoki, Yoshiro Nakano and Daisuke Yamamoto (DOI: 10.1002/arch.10011) which appeared in Volume 49, Number 2, 2002 on pages 94–101 was subpar. The reproduction did not accurately capture the fine detail of the author’s original prints. The figure from page 96 and legend is reprinted herein.
Renal flares are common in patients with severe proliferative lupus nephritis treated with pulse immunosuppressive therapy: Long‐term followup of a cohort of 145 patients participating in randomized controlled studies
Authors: Illei G. G. , Takada K. , Parkin D. , Austin H. A. , Crane M. , Yarboro C. H. , Vaughan E. M. , Kuroiwa T. , Danning C. L. , Pando J. , Steinberg A. D. , Gourley M. F. , Klippel J. H. , Balow J. E. , Boumpas D. T.
Published: August 2002

Objective

Immunosuppressive agents have become the standard of therapy for proliferative lupus nephritis, but some patients may relapse after discontinuing treatment. We reviewed the cases of renal flares in a cohort of patients who participated in 2 randomized controlled clinical trials at the National Institutes of Health and explored the prevalence, outcome, and predictive factors of renal flares.

Methods

Data were obtained on 145 patients treated with pulse cyclophosphamide, pulse methylprednisolone, or the combination of both. Patients had not received immunosuppressive therapy for at least 6 months and had experienced complete or partial response according to defined criteria. Renal flares were classified as either proteinuric or nephritic based on changes in urinary protein and sediment. Most patients who experienced a flare received additional immunosuppressive therapy.

Results

Seventy‐three patients had a complete response, and 19 had partial response/stabilization. Forty‐one of these patients (45%) experienced renal flares (nephritic in 33, proteinuric in 8) after a mean followup of 117 months; 31 of them received additional immunosuppressive therapy. The median time to renal flare was 36 months in the complete responders and 18 months in the partial responders. Eleven of the 41 patients (27%) progressed to end‐stage renal disease (ESRD); 9 had nephritic flares (all severe except for 1) and 2 had proteinuric flares (1 in each responder group). Compared with patients who had a complete response, those with a partial response were more likely to experience a flare, to have a severe nephritic flare, or to progress to ESRD. Low C4 at the time of response and African American ethnicity were significant independent risk factors for renal flare, by multivariate Cox proportional hazards analysis.

Conclusion

Nephritic flares are common in patients with proliferative lupus nephritis, even in those with a complete response to therapy, but they do not necessarily result in loss of renal function if treated with additional immunosuppressive agents. Renal flares are an important feature of the natural history of lupus nephritis and provide an opportunity for additional preventive strategies, as well as measures of efficacy in future therapeutic trials.
Step‐down approach using either cyclosporin A or methotrexate as maintenance therapy in early rheumatoid arthritis
Authors: Marchesoni Antonio , Battafarano Norma , Arreghini Marco , Pellerito Raffaele , Cagnoli Maria , Prudente Porziana , Cerase Alfonso , Priolo Francesco , Tosi Sergio
Published: August 2002

Objective

To evaluate the feasibility and outcome of the step‐down approach using either cyclosporin A (CSA) or methotrexate (MTX) as maintenance therapy following 6 months treatment with these 2 agents in combination in early, nonerosive rheumatoid arthritis (RA).

Methods

Fifty‐seven patients younger than 65 years with early, nonerosive RA were first treated with CSA and MTX in combination for 6 months. They were then randomly stepped down to single‐agent maintenance treatment for another 18 months. Safety, clinical efficacy, survival on treatment, and radiographic progression were evaluated.

Results

When being treated with combination therapy, 7 of the 57 patients (12.3%) withdrew because of adverse events. Of the remaining 50 patients, 42 (84.0%) were American College of Rheumatology (ACR) 20% responders, 30 (60.0%) were ACR 50% responders, and 23 (46.0%) were ACR 70% responders. At month 6, 22 patients were randomized to CSA and 27 to MTX. During this trial period, the treatment was discontinued by 16 patients taking CSA (mainly because of loss of efficacy) and by 4 taking MTX. At month 24, the probability (± SEM) of survival on treatment was 0.273 ± 0.09 for CSA and 0.852 ± 0.07 for MTX. Of the 6 CSA patients who completed the trial, 4 (66.7%) were ACR 20% responders, and 3 (50%) were both ACR 50% and ACR 70% responders. Of the 23 completers in the MTX arm, 21 (91.3%) were ACR 20% responders, 18 (78.3%) were ACR 50%, and 10 (43.5%) were ACR 70% responders. The treatment was not responsible for severe adverse events. Radiography showed a slow progression in the damage score and number of eroded joints in both treatment groups.

Conclusion

Stepping down to single agent maintenance therapy following 6 months of combination treatment with CSA and MTX in early RA was only successful with MTX. Because this treatment did not prevent some radiographic progression, other approaches (e.g., step‐up approach) may be more appropriate in early RA.
A personal agent for Chinese financial news on the Web
Authors: Yang Christopher C. , Chung Alan
Published: August 2002

As the Web has become a major channel of information dissemination, many newspapers expand their services by providing electronic versions of news information on the Web. However, most investors find it difficult to search for the financial information of interest from the huge Web information space–information overloading problem. In this article, we present a personal agent that utilizes user profiles and user relevance feedback to search for the Chinese Web financial news articles on behalf of users. A Chinese indexing component is developed to index the continuously fetched Chinese financial news articles. User profiles capture the basic knowledge of user preferences based on the sources of news articles, the regions of the news reported, categories of industries related, the listed companies, and user‐specified keywords. User feedback captures the semantics of the user rated news articles. The search engine ranks the top 20 news articles that users are most interested in and report to the user daily or on demand. Experiments are conducted to measure the performance of the agents based on the inputs from user profiles and user feedback. It shows that simply using the user profiles does not increase the precision of the retrieval. However, user relevance feedback helps to increase the performance of the retrieval as the user interact with the system until it reaches the optimal performance. Combining both user profiles and user relevance feedback produces the best performance.
MetaSpider: Meta‐searching and categorization on the Web
Authors: Chen Hsinchun , Fan Haiyan , Chau Michael , Zeng Daniel
Published: August 2002

It has become increasingly difficult to locate relevant information on the Web, even with the help of Web search engines. Two approaches to addressing the low precision and poor presentation of search results of current search tools are studied: meta‐search and document categorization. Meta‐search engines improve precision by selecting and integrating search results from generic or domain‐specific Web search engines or other resources. Document categorization promises better organization and presentation of retrieved results. This article introduces MetaSpider, a meta‐search engine that has real‐time indexing and categorizing functions. We report in this paper the major components of MetaSpider and discuss related technical approaches. Initial results of a user evaluation study comparing MetaSpider, NorthernLight, and MetaCrawler in terms of clustering performance and of time and effort expended show that MetaSpider performed best in precision rate, but disclose no statistically significant differences in recall rate and time requirements. Our experimental study also reveals that MetaSpider exhibited a higher level of automation than the other two systems and facilitated efficient searching by providing the user with an organized, comprehensive view of the retrieved documents.
Forecasting stock index volatility
Authors: Bramante Riccardo , Luigi Santamaria
Published: August 2002

Accurate volatility forecasting is the key to successful risk analysis. In fact, volatility forecasts lie at the centre of many financial systems, such as value at risk modelling and pricing of derivative securities. This paper is concerned with how to construct stock index volatility predictors using the returns histories of the stocks that define the Index. Specifically, our approach presupposes that the total volatility of the index returns can be explained by the volatility of the related components. Copyright © 2001 John Wiley & Sons, Ltd.
Comparative pharmacokinetics, safety, and tolerability after subcutaneous administration of recombinant human erythropoietin formulated with different stabilizers
Authors: Cheung Wing K. , Natarajan Jaya , Sanders Marilyn , Vercammen Els
Published: August 2002

This report summarizes the results of two double‐blind, single‐center, randomized studies that used a two‐period crossover design. The objective of these two studies was to compare the safety, tolerability, pharmacokinetics, and pain score at the subcutaneous (sc) injection site of a phosphate‐buffered recombinant human erythropoietin (EPREX®, epoetin alfa, r‐HuEPO) formulated with a new stabilizer (glycine and Polysorbate 80) with the commercially available EPREX® formulations, which uses human serum albumin (HSA) as the stabilizer. Twenty‐four healthy male volunteers were enrolled in each of the two studies. In the first study, subjects received a single 150 IU/kg sc dose of r‐HuEPO using the 2000 IU/mL (2K) phosphate‐buffered formulation with or without the new stabilizer (12 subjects/group). In the second study, subjects received a single 750 IU/kg sc dose of r‐HuEPO using the 40 000 IU/mL (40K) phosphate‐buffered formulation with or without the new stabilizer (12 subjects/group). In each study, r‐HuEPO was administered over two separate dosing periods, each separated with a 28‐day washout period. There were no significant differences in AUC and Cmax for either strength of r‐HuEPO formulated with or without the new stabilizer, indicating that the absorption and disposition characteristics of the two formulations were similar after sc administration. Both r‐HuEPO strengths with and without the new stabilizer were safe and well tolerated; the safety and tolerability profiles of both formulations for each r‐HuEPO concentration were comparable. There were no statistically significant differences in pain score for either strength of r‐HuEPO with and without the new stabilizer. It was concluded that the two phosphate‐buffered r‐HuEPO concentrations formulated with and without the new stabilizer are pharmacokinetically equivalent. Copyright © 2000 John Wiley & Sons, Ltd.