bluuebunny/crossref_metadata_2025 huggingface dataset:
Isotopic tracking of prehistoric pinniped foraging and distribution along the central California coast: preliminary results
Authors: Burton R. K. , Gifford‐Gonzalez D. , Snodgrass J. J. , Koch P. L.
Published: August 2002

Zooarchaeological data from Monterey Bay and the adjacent central California coast corroborate earlier observations from northern California and Oregon that Callorhinus ursinus (northern fur seal) was a much more common component in prehistoric marine mammal prey than its present pelagic distribution and foraging habits would predict. C. ursinus remains from mid‐Holocene Monterey Bay occurrences are predominantly from female individuals, associated with an inshore piscifauna, and lack associated artifactual evidence for deep water exploitation. Taken together with evidence from Oregon, this suggests that mid‐Holocene C. ursinus populations had different foraging, resting, and, arguably, reproductive behaviours than historically reported. Currently debated is whether the contrast between prehistoric and present patterns of pinniped species representation results from: 1) late Holocene prehistoric resource depression by aboriginal hunters, 2) depredations of the early historic fur trade, or 3) non‐anthropogenic climatic or oceanographic change. The issue has thus far been addressed with presence or absence data on pinniped species and age/sex classes in dated contexts. While these are fundamental data, they cannot shed light on the nature of foraging behaviour of the species in question, a key dimension of the problem. This paper reports a pilot study utilizing stable isotope analysis aimed to elucidate prehistoric pinniped foraging patterns, specifically that of C. ursinus. Elements from six archaeological sites in Monterey and Santa Cruz counties were analysed for stable isotope compositions of carbon and nitrogen in bone collagen and compared to a latitudinally ordered modern dataset. Results for archaeological C. ursinus strongly suggest that prehistoric animals habitually foraged at lower latitudes than characterize the species today, supporting earlier claims of their year‐round residency south of Alaska. Copyright © 2002 John Wiley & Sons, Ltd.
Hydrophobically modified polyelectrolytes II: synthesis and characterization of poly(acrylic acid‐co‐alkyl acrylate)
Authors: Zhuang Dong‐qing , Ai‐hua Da Jie Chen , Zhang Yun‐xiang , Dieing Reinhold , Ma Lian , Haeussling Lukas
Published: August 2002

A series of hydrophobically modified poly(acrylic acid)(R
H‐PAA) were synthesized by solution copolymerization of acrylic acid with a small amount of alkyl acrylate (alkyl chain with a length of 8, 12, 14, 16, 18) and their solution properties were also systematically studied. It was found that the random distribution of alkyl acrylate along the polymeric backbone imparts these new materials pronounced associating ability in aqueous solution and the associating abilities vary with the chain length of the hydrophobic groups. In dilute solution, intramolecular association is observed from the intrinsic viscosity and the dependence of the intrinsic viscosity on chain length and ionic strength is also discussed. In semiconcentration solution, the modified polymers exhibit viscosities of several orders of magnitude higher than the unmodified poly(sodium acrylate) due to the strong intermolecular hydrophobic association. And the viscosifying effects become more significant with the increasing length of the alkyl chain. The copolymer solutions are highly pseudoplastic. Evidences for the hydrophobically associating interaction between hydrocarbon groups are provided by the dependence of the Brookfield viscosity on concentration, temperature, shear rate, ionic strength and pH. Copyright © 2001 John Wiley & Sons, Ltd.
Preparation of silica‐supported methylcellulose‐L‐proline–Pt complex and its catalytic behaviors in asymmetric hydrogenation of propiophenone
Authors: Huang Kai , Xue Lei , Huang Mei‐Yu , Jiang Ying‐Yan
Published: August 2002

A new chiral polymer–metal complex, silica‐supported methylcellulose‐L‐proline–Pt complex (SiO2‐MC‐LP–Pt) has been found to be a high optically active catalyst for asymmetric hydrogenation of propiophenone to (R)‐1‐phenyl‐1‐propanol at 30 °C and under atmospheric hydrogen pressure. The product and optical yields of 1–phenyl‐1‐propanol amounted to 62.5 and 92.2%, respectively. The product and optical yields were remarkably affected by the Pt content in the complex, the kind of solvent and the reaction temperature. This catalyst was very stable and could be reused several times without remarkable change in optical catalytic activity. Copyright © 2001 John Wiley & Sons, Ltd.
Trends in primary care antibiotic prescribing in England 1994–1998
Authors: Unsworth L. , Walley T.
Published: August 2002

Purpose

To investigate the changing decisions to prescribe antibiotics as manifest in the patterns of prescriptions dispensed in England, and to investigate antibiotic prescribing in different types of practice.

Methods

Antibiotic prescribing data and practice characteristics collected for every practice in England for the years 1994/5–1997/8. Morbidity data for common infections was also obtained from published sources.

Results

Antibiotic prescribing was related to practice characteristics, with high prescribing in deprived and single‐handed practices in particular. There was a fall in antibiotic prescribing in all types of practice of practice over the period of the study. Morbidity data from other sources shows a fall in diagnosed morbidity from some infectious diseases over the same period. There were no differences in choice of antibiotic in different types of practice.

Conclusions

The fall in antibiotic prescribing is universal across all kinds of practices and is possibly related to the fall in diagnoses. It is uncertain whether this reflects true morbidity. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of the silica content on rheological behaviour and cure characteristics of silica‐filled styrene–butadiene rubber compounds
Authors: Choi Sung‐Seen
Published: August 2002

Rheological behaviour and cure characteristics of silica‐filled styrene–butadiene rubber (SBR) compounds and SBR compounds filled with both silica and carbon black with different silica contents were investigated. Rheocurves of the time versus the torque of the compounds showed specific trends with the silica content. For the compounds with low silica content (less than 50 phr), the torque decreased immediately after the steep increase at the initial point of the rheocurve and then increased very slowly. For the compounds with high silica content (more than 50 phr), the rheographs showed two minimum torque points; the torque decreased immediately after the steep increase at the start point of the rheocurve and then increased sharply before reaching the second minimum point. This can be explained by the strong filler–filler interaction of silica. The minimum torque of the compound increased slightly with an increase of the silica content up to 50 phr silica content and then increased appreciably. For the silica‐filled compounds, cure times of the t02, t40, and t90 became shorter with an increase of the filler content. For the compounds filled with both silica and carbon black (total filler content of 80 phr), the cure times became longer with an increase of the silica content ratio.

© 2001 Society of Chemical Industry
Reactive processing of acrylic–polyurea interpenetrating networks: reaction kinetic studies
Authors: Stanford John L , Ryan Anthony J , Yang Ying
Published: August 2002

Interpenetrating networks (IPNs), comprising a crosslinked acrylic polymer as one component and either a polyurea, a segmented copolyurea or a copoly(urea–isocyanurate) as the other component, have been formed by reaction injection moulding (RIM). The effects on the processability and the formation of the IPNs of (i) the crosslinker concentration in the acrylic component, (ii) the functionality of the amine‐functionalized polyether used for the polyurea, and (iii) the weight fractions of acrylic components are evaluated. Reaction kinetics during RIM processing of the IPNs are studied using adiabatic temperature rise (ATR) measurements. The macroscopic structures of RIM materials, determined via optical microscopy, are used to assess the mixing characteristics operative during reactive processing of the various IPNs. The results are interpreted in terms of differences in the rates of polymerization and in the solubilities of the acrylic‐ and polyurea‐forming components.

© 2001 Society of Chemical Industry
Synthesis and characterization of a novel functional monomer containing cyano and propenylphenoxy groups and the properties of its copolymer with bismaleimide (BMI)
Authors: Fang Qiang , Yu Yi‐Hua , Huang Hao , Chao Qi‐Rong , Jiang Lu‐Xia
Published: August 2002

A novel functional monomer containing cyano and propenylphenoxy groups, 2,6‐di{2‐[(E)‐l‐propenyl]phenoxy}benzonitrile (DPPB) was prepared with high stereospecificity by the reaction of 2,6‐dichlorobenzonitrile and 2‐allylphenol in a mixed solvent system of N‐methylpyrrolidone (NMP)/toluene in the presence of anhydrous potassium carbonate. The chemical structure of the product was characterized by FTIR, 1H NMR and 13C NMR. The monomer was then used to modify a popular commercial bismaleimide, 4,4‐bismaleimidodiphenylmethane (BMDPM), for improving the shear strength of the resin. The results showed that the modified resin could attain 4.7 times the shear strength of neat BMDPM and good heat resistance when the composition of DPPB in the modified resin was 45% (by weight).

© 2002 Society of Chemical Industry
Synthesis, NMR characterization and pharmacological evaluation of ligands derived from diprenorphine for central opioid receptors imaging
Authors: Bourrel François , Massou Stéphane , Baltas Michel , Bergon Michel , Tafani Mathieu , Esquere Jean‐Paul , Tisnès Pierre , Prigent Yann
Published: August 2002

The aim of this work was to explore the synthesis of a tosylated derivative of diprenorphine (DPN) able to be radiolabeled with either fluorine‐18 or iodine‐123, making it suitable for PET or SPECT imaging studies of central opioid receptors, respectively. The strategy was based on the reactivity of the C‐19 alcohol tertiary function. As an unexpected deacetylation of the phenolic function of the diprenorphine occurred, the prosthetic group reacted with the deprotected C‐3 phenolic function instead of the C‐19 alcohol group. UV spectroscopy and 1H and 13C NMR studies provided good evidence for the 3‐phenolic substituted diprenorphine structure. Thorough 2D NMR experiments such as 1H–1H COSY, 1H–1H TOCSY, 1H–13C HMQC, 1H–13C HMBC and 1H–1H NOESY allowed us to assign fully 3‐O‐[(Z)‐4‐fluorobut‐2‐enyl] diprenorphine (10a) and gave us an unambiguous proof of the C‐3 prosthetic group position. In vitro binding studies showed low affinity for both fluoro and iodo derivatives of diprenorphine, Ki = 0.31 ± 0.05 and 0.09 ± 0.03 µM, respectively, for mouse brain membranes, these inhibition constants also being in agreement with a 3‐phenolic substituted structure. Copyright © 2001 John Wiley & Sons, Ltd.
Dual‐parameter correlations on rate of dehydration step of a condensation reaction in aqueous solutions of ethanol, propan‐2‐ol and 2‐methylpropan‐2‐ol
Authors: Yangjeh A. Habibi , Gholami M. R. , Mostaghim R.
Published: August 2002

The reaction kinetics of the dehydration step of the condensation reaction between phenylhydrazine and benzaldehyde was studied spectrophotometrically in aqueous solutions of ethanol, propan‐2‐ol and 2‐methylpropan‐2‐ol at pH 11.5 at 25 °C. The apparent second‐order rate constants k2app of the reaction increase with mole fraction of water in all the aqueous solutions. Single‐parameter correlations of log k2app versus π* (dipolarity/polarizability), α (hydrogen‐bond donor acidity) and $E_{\rm T}^{\rm N}$ (normalized polarity parameter) were obtained in all the aqueous solutions. In all cases, the correlations versus $E_{\rm T}^{\rm N}$ and π* are acceptable, but correlations versus α are poor (e.g. in aqueous solutions of ethanol the correlation coefficients are 0.964, 0.967, and 0.751 respectively). The results of dual‐parameter correlations of log k2app versus π* and α in all cases represent improvements with regard to the single‐parameter models (in aqueous solutions of ethanol r = 0.995; s.e. = 0.038; n = 13). The apparent second‐order rate constants of the reaction increase with α, π* and $E_{\rm T}^{\rm N}$. Increasing the hydrogen‐bond donor acidity of the solvent stabilizes the activated complex of the reaction via hydrogen‐bond formation with the intermediate. A dual‐parameter equation of log k2app versus π* and α was obtained for the combined data set of aqueous solutions (n = 35, r = 0.989, s.e. = 0.062, F2,32 = 719.21), in which π* has the major effect on the reaction rate relative to α. Copyright © 2001 John Wiley & Sons, Ltd.
Liquid‐crystalline organic–inorganic hybrid polymers with functionalized silsesquioxanes
Authors: Kim Kyung‐Min , Chujo Yoshiki
Published: August 2002

Liquid‐crystalline (LC) hybrid polymers with functionalized silsesquioxanes with various proportions of LC monomer were synthesized by the reaction of polyhedral oligomeric silsesquioxane (POSS) macromonomer with methacrylate monomer having an LC moiety under common free‐radical conditions. The obtained LC hybrid polymers were soluble in common solvents such as tetrahydrofuran, toluene, and chloroform, and their structures were characterized with Fourier transform infrared, 1H NMR, and 29Si NMR. The thermal stability of the hybrid polymers was increased with an increasing ratio of POSS moieties as the inorganic part. Because of the steric hindrance caused by the bulkiness of the POSS macromonomer, the number‐average molecular weight of the hybrid polymers gradually decreased as the molar percentage of POSS in the feed increased. Their liquid crystallinities were very dependent on the POSS segments of the hybrid polymers behaving as hard, compact components. The hybrid polymer with 90 mol % LC moiety (Cube‐LC90) showed liquid crystallinity, larger glass‐transition temperatures, and better stability with respect to the LC homopolymer. The results of differential scanning calorimetry and optical polarizing microscopy showed that Cube‐LC90 had a smectic‐mesophase‐like fine‐grained texture. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4035–4043, 2001
Long‐lived intermediates in reversible addition–fragmentation chain‐transfer (RAFT) polymerization generated by γ radiation
Authors: Barner‐Kowollik Christopher , Vana Philipp , Quinn John F. , Davis Thomas P.
Published: August 2002

A novel experimental procedure is presented that allowed probing of reversible addition–fragmentation chain‐transfer (RAFT) free‐radical polymerizations for long‐lived species. The new experimental sequence consisted of gamma irradiation of a mixture of initial RAFT agent (cumyl dithiobenzoate) and monomer at ambient temperature, a subsequent predetermined waiting period without initiation source also at ambient temperature, and then heating of the reaction mixture to a significantly higher temperature. After each sequence step, the monomer conversion and molecular weight distribution were determined, indicating that controlled polymer formation occurs only during the heating period. The results indicated that stable intermediates (either radical or nonradical in nature) are present in such experiments because thermal self‐initiation of the monomer can be excluded as the reason for polymer formation. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1058–1063, 2002
Negative‐working photoresist of methacrylate polymers based on the transesterification of the 2‐hydroxyethyl group in the presence of an acid
Authors: Lee Jongsoo , Aoai Toshiaki , Kondo Syun'ichi , Miyagawa Nobukazu , Takahara Shigeru , Yamaoka Tsuguo
Published: August 2002

This article reports a novel crosslinking functionality of the 2‐hydroxyethyl methacrylate unit (HEMA) in the presence of an acid. The polymeric compositions, consisting of a polymer containing the HEMA unit and a photoacid generator, were insolubilized in an aqueous base developer on exposure to UV light and a successive baking process to provide a negative‐working photoresist. A series of poly(benzyl methacrylate‐co‐methacrylic acid‐co‐2‐hydroxyethyl methacrylate) terpolymers with various contents of HEMA were prepared to elucidate the photopolymeric characteristics. The polymer behavior in films was examined by a comparison of the photosensitivity and IR spectroscopic method. Experiments with a model compound were also carried out. On the basis of the results, we found that the resist was insolubilized by crosslinking through the transesterification of HEMA segments due to acid generated from the photoacid generator and subsequent heating. The advantage of using the 2‐hydroxyethyl group is that in the terpolymer, the HEMA unit is transparent at a short‐wavelength region and is a promising crosslinking unit for ArF lithographic photoresists. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1858–1867, 2002
Ionic poly(p‐phenylene terephthalamide)s: Solubility and thermal stability
Authors: Chen W. C. , Sauer J. A. , Hara M.
Published: August 2002

Ionic sulfonate groups were incorporated onto molecules of the rigid‐rod polymer poly(p‐phenylene terephthalamide) (PPTA) in two different positions. In one type, S‐PPTA, ionic sulfonate groups were attached to the phenylene ring of the backbone chain. S‐PPTA solubility was achieved in dimethylsulfoxide (DMSO) when 50% of the repeat units contained an ionic group. In the second type, PPTA‐PS, where ionic propanesulfonate groups served as side chains, solubility was achieved in DMSO when 30% of the repeat units contained the ionic group. For both of the partially sulfonated ionic polymers, the thermal stability was enhanced in comparison with the stability of the acid‐form polymers, but it was less than that of PPTA. The effect was more dramatic when the ionic groups were located at the end of side chains. The nature of the counterion also played a role, with doubly ionized calcium giving the best results. Polarized light micrographs of the ionic PPTA polymers displaced birefringent patterns and indicated that greater rigidity was present when the ionic groups were directly attached to the backbone, rather than at the end of a short side chain. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2888–2897, 2001
Influence of long‐chain branching on the miscibility of poly(ethylene‐r‐ethylethylene) blends with different microstructures
Authors: Chen Ying Ying , Lodge Timothy P. , Bates Frank S.
Published: August 2002

The melt miscibility of two series of poly(ethylene‐r‐ethylethylene) (PEExx) polymers with different percentages (xx) of ethylethylene (EE) repeat units was examined with small‐angle neutron scattering (SANS). The first series consisted of comb/linear blends in which the first component is a heavily branched comb polymer (B90) containing 90% EE and an average of 62 long branches with a weight‐average molecular weight (MW) of 5.5 kg/mol attached to a backbone with MW = 10.0 kg/mol. The comb polymer was blended with six linear PEExx copolymers, all of which had MW ≈ 60 kg/mol and EE percentages ranging from 55 to 90%; they were denoted L55 to L90, with the number referring to the percentage of EE repeat units. The second series consisted of linear/linear blends; the first component, with MW = 220 kg/mol and 90% EE, was denoted L90A, and the second components were the same series of linear polymers, with MW ≈ 60 kg/mol and various EE compositions. The concentrations investigated were 50/50 w/w, except for the blend of branched B90 and linear L90 (both components were 90% EE), for which 25/75 and 75/25 concentrations were also examined. The SANS results indicated that for the comb/linear blends, only the dB90/L90 blends were miscible, whereas the other five blends phase‐separated; for the linear/linear blends, dL90A/L83 and dL90A/L78 were miscible, whereas the other three blends were immiscible. These results indicate that long‐chain branching significantly narrowed the miscibility window of these polyolefin blends. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 466–477, 2002; DOI 10.1002/polb.10102
Development of a methodology to predict material properties from environmental exposure. I. Kinetic treatment
Authors: Robertson J. E. , Ward T. C.
Published: August 2002

This study focuses on bisphenol A polycarbonate and tracks changes in the properties of this material as a function of the degree of degradation, τ, induced by a hostile environment. Among many possible environmental effects, we have limited this investigation to those associated with elevated temperature, although the methodology is general. This τ parameter is a product of the kinetic rate constant, k, found from isothermal kinetics, and the time of degradation, t. The elucidation of τ has been linked to the measurement of the molecular weight distribution, which, in turn, can be related to various properties to yield valuable predictive relationships. Only the thermal history of the polymer and its initial properties are required for the model. This technique is not limited to a specific polymer or even to thermal degradation. As long as the kinetics of the process can be mathematically modeled, this approach should apply to a host of other situations, providing property prediction simply from knowledge of the material history. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 794–801, 2002
Effect of stereosequences on crystallinity and properties of zone‐drawn poly(vinyl alcohol) microfibrils
Authors: Lyoo Won Seok , Kim Joon Ho , Koo Kang , Lee Joon Seok , Kim Sam Soo , Yoon Won Sik , Ji Byung Chul , Kwon Ick Chan , Lee Chul Joo
Published: August 2002

To effectively orient the molecular chains of novel syndiotactic poly(vinyl alcohol) (PVA) microfibrillar fiber (PVA fibril), a high‐temperature zone‐drawing method was adopted. The PVA fibrils were directly prepared from the saponification and in situ fibrillation without a spinning procedure. The maximum draw ratio of the PVA fibril increased with a decrease in the syndiotactic diad (r‐diad) content, indicating that the deformability of PVA molecules was lowered in higher syndiotactic PVA. Degree of crystal orientations up to 0.990 were achieved by stretching the PVA fibril with the r‐diad content of 65.1% and the original degree of crystal orientation of 0.902 at 250 °C close to its crystal melting temperature (Tm). When the same draw ratio was applied to the fibrils, a higher crystal orientation was achieved for the fibrils having higher syndiotacticity. Wide‐angle X‐ray data show that the longitudinal crystal sizes of drawn PVA fibrils were larger in higher syndiotacticities. The degree of crystal orientation, crystallinity, Tm, longitudinal crystal size, and tensile strength of the maximum drawn PVA fibril with a r‐diad content of 65.1% were 0.99, 0.97, 279 °C, 187 Å, and 4.66 N/tex, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1263–1271, 2001
Photoviscoelastic behavior of amorphous polymers during transition from the glassy to rubbery state
Authors: Shyu G. D. , Isayev A. I. , Li C. T.
Published: August 2002

Tensile stress‐relaxation experiments with simultaneous measurements of Young's relaxation modulus, E, and the strain‐optical coefficient, Cϵ, were performed on two amorphous polymers—polystyrene (PS) and polycarbonate (PC)—over a wide range of temperatures and times. Master curves of these material functions were obtained via the time‐temperature superposition principle. The value of Cϵ of PS is positive in the glassy state at low temperature and time; then it relaxes and becomes negative and passes through a minimum in the transition zone from the glassy to rubbery state at an intermediate temperature and time and then monotonically increases with time, approaching zero at a large time. The stress‐optical coefficient of PS is calculated from the value of Cϵ. It is positive at low temperature and time, decreases, passes through zero, becomes negative with increasing temperature and time in the transition zone from the glassy to rubbery state, and finally reaches a constant large negative value in the rubbery state. In contrast, the value of Cϵ of PC is always positive being a constant in the glassy state and continuously relaxes to zero at high temperature and time. The value of Cσ of PC is also positive being a constant in the glassy state and increases to a constant value in the rubbery state. The obtained information on the photoelastic behavior of PS and PC is useful for calculating the residual birefringence and stresses in plastic products. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2252–2262, 2001
Respiratory syncytial virus bronchiolitis: Disease severity, interleukin‐8, and virus genotype*
Authors: Smyth Rosalind L. , Mobbs Kevin J. , O'Hea Una , Ashby Deborah , Hart C. Anthony
Published: August 2002

In infants with respiratory syncytial virus (RSV) bronchiolitis, we investigated whether disease severity is associated with the genotype of the infecting virus, or with the infant's immunological response to the infection, as determined by measurement of interleukin‐8 mRNA in the nasopharyngeal aspirate. This was a cross‐sectional observational study, performed in the Accident and Emergency Department, wards, and Intensive Care Unit of a large pediatric hospital. Participants included 276 infants with respiratory syncytial virus infection. Outcome variables included: disease severity (infants requiring oxygen or ventilation were classified as having severe disease); RSV virus genotype (determined according to typing scheme based on the nucleoprotein and G glycoprotein genes); and amount of interleukin‐8 mRNA in the nasopharyngeal aspirate, as measured by a semiquantitative polymerase chain reaction assay. This was corrected for the amount of cellular material in the sample by expressing it relative to mRNA for a constitutively expressed gene, HGPRT.

We found a highly significant association between the ratio of interleukin‐8 mRNA/HGPRT mRNA in the nasopharyngeal aspirate and the occurrence of severe disease. Odds ratio per unit increase of interleukin‐8 mRNA/HGPRT mRNA was 1.15 (95% CI, 1.06, 1.24), P = 0.0004. There was no association between virus genotype and either disease severity or amount of interleukin‐8 mRNA/HGPRT mRNA.

In conclusion, there is a strong, dose‐related association between interleukin‐8 mRNA produced locally in the airways and disease severity, and a lack of association with virus genotype. This suggests that clinical manifestations of respiratory syncytial virus bronchiolitis are determined by local immunological responses to infection, rather than by characteristics of the infecting virus. Pediatr Pulmonol. 2002; 33:339–346. © 2002 Wiley‐Liss, Inc.
Platelet endothelial cell adhesion molecule‐1 and capillary loading in premature infants with and without chronic lung disease*
Authors: Olsen Steven L. , Thibeault Donald W. , Mabry Sherry M. , Norberg Michael , Truog William E.
Published: August 2002

It was our objective to quantify platelet endothelial cell adhesion molecule‐1 (PECAM‐1) by immunohistochemistry in control infants of 22–50 weeks postconceptual age, and to correlate it with varying degrees of neonatal chronic lung disease (CLD). We tested the hypothesis that the density of PECAM‐1 staining will positively correlate with increasing gestational age (GA) and the inflammatory process in CLD. A library of postmortem lung tissue of infants receiving ventilator care was accessed. The population consisted of 35 control infants exposed briefly to oxygen and positive pressure ventilation, and 31 infants who were 23–30 weeks GA with mild to severe CLD. A monoclonal anti‐human PECAM‐1 antibody was used to stain 5‐μm paraffin sections. The slides were viewed at a magnification of × 40 by a blinded examiner. Twenty consecutive fields from standardly expanded tissue samples were viewed, and the volume density of PECAM‐1 (VV PECAM) per parenchyma was measured, using point counting. In addition, 1‐μm sections from 15 controls and 5 infants with CLD were stained with Toluidine blue and viewed under oil at a magnification of × 100, and the volume density of capillaries (VV CAP) and capillary load (CL) were calculated.

The VV PECAM increased significantly with GA in controls (r = 0.72, P < 0.001). There was no relationship between VV PECAM and severity of CLD. Both VV CAP and CL increased significantly with GA (r = 0.93, P < 0.001; r = 0.94, P < 0.001, respectively). The infants with CLD had a normal or increased VV CAP and CL compared to controls.

In summary, VV PECAM, VV CAP, and CL increased significantly with gestational age in control infants, but the postconceptional age range in CLD infants was too short to determine whether the VV PECAM changed. Infants with CLD had normal or increased VV CAP and CL compared to controls. The PECAM‐1 immunostain does not appear to be a sensitive method for assessing capillary density in infants with CLD. These findings of normal or increased capillary load may represent a vascular adaptation for the lack of secondary septation and decreased surface area in CLD. Pediatr Pulmonol. 2002; 33:255–262. © 2002 Wiley‐Liss, Inc.
The regulatory system for aquaculture in the Republic of Ireland
Authors: Grist Berna
Published: August 2002

The control of aquaculture in the Republic of Ireland falls under a number of different legislative codes and, consequently, responsibility for the regulation of the industry is divided between a number of ministers and state agencies. The principal responsibility lies with the Minister for the Marine and Natural Resources. The 1997 Fisheries Act was framed to replace an outdated regulatory system with one which would enjoy the confidence of a rapidly expanding industry and of all other relevant interests, in particular by establishing an independent authority for the determination of aquaculture licence appeals. Powers in relation to the authorisation and control of medicines are shared between the Minister for Agriculture and the Minister for Health, while local authorities are responsible for planning permission and discharge licences in respect of land‐based facilities.

© 2002 Society of Chemical Industry
Biological activity of kiwifruit peel extracts
Authors: Motohashi Noboru , Shirataki Yoshiaki , Kawase Masami , Tani Satoru , Sakagami Hiroshi , Satoh Kazue , Kurihara Teruo , Nakashima Hideki , Wolfard Kristina , Miskolci Csilla , Molnár Joseph
Published: August 2002

Various bioactive substances in kiwifruit extracts were fractionated by organic solvent extractions, followed by silica gel and ODS chromatographies. Both cytotoxic activity and multi‐drug resistance reversal activity were found in the less polar fractions. Cytotoxic activity was not always parallel the radical intensity. Antibacterial activity was distributed into various fractions and all fractions were inactive against Candida albicans and H. pylori. Only 70% methanol extracts showed anti‐human immunodeficiency virus activity, and produced a broad ESR signal under alkaline conditions, in a fashion similar to lignin. These fractions also effectively scavenged O2− produced by the xanthine–xanthine oxidase reaction, suggesting a bimodal (pro‐oxidant and antioxidant) action. These data suggest a medicinal efficacy of kiwifruit peel extracts. Copyright © 2001 John Wiley & Sons, Ltd.
Imperfect inspection of a multi‐attribute deteriorating production system—a continuous time model
Authors: Rabinowitz Gad , Yahalom Orly
Published: August 2002

The reliability of a multi‐attribute deteriorating production system is controlled using versatile identical inspection facilities. An attribute state is dichotomous (up designates proper function versus down). A product item is conforming if all the system attributes are up when it is produced. When a system attribute is detected as down it is restored back to an up state. Inspection of an attribute can rely on observations of the system, recently produced items, or both. Inspection policy determines the inspection capacity, frequency of inspecting each attribute and inspection schedule. These decisions involve a tradeoff between the cost of inspectors and the loss associated with the roportion of non‐conforming items due to lack of adequate inspection. Three models are introduced, analyzed and solved. In the first model, inspection and restoration are perfect, product attribute is up (down) when the system attribute is up (down), and restoration is immediate. The assumptions of perfect inspection and restoration are relaxed in the second model. The third model relaxes in addition the assumption of immediate restoration. An efficient heuristic solution scheme is provided for solving these models. Sensitivity of the solution to system parameters is studied. Numerical experiments provide some insights regarding the combined effect of imperfect production, inspection and restoration, in various conditions of inspection and restoration durations. Copyright © 2001 John Wiley & Sons Ltd.
Structural and electronic properties of La‐doped CaTiO3 crystal
Authors: Erazo Franklin , Stashans Arvids
Published: August 2002

There is experimental and computational evidence that some important properties such as electrical conductivity and ferroelectricity in the CaTiO3 crystal change according to the dopant states. Using an INDO quantum‐chemical computational method modified for crystal calculations we explore the stability of the La‐doped CaTiO3 crystal in both phases, cubic and orthorhombic. The calculations are carried out by means of the supercell model based on the LUC (large unit cell) approach as it is implemented into the CLUSTERD computer code. The equilibrium geometry for impurity is found together with the crystalline lattice distortions. Atomic displacements and relaxation energies are analyzed in a comparative manner for the two crystallographic phases. A new effect of electron transfer from the local one‐electron energy level within the band‐gap to the conduction band is observed. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Vacancy interactions in cluster expansion formalism
Authors: Fuks David , Dorfman Simon
Published: August 2002

Vacancies in metal are studied in the model of the atom‐vacancy solid solution. Vacancy formation energy is discussed in terms of cluster expansion formalism. It is shown that effective interaction of vacancies is formally included in the energy of vacancy formation. The cluster expansion method illustrates that pairwise and nonpairwise interactions between atoms and vacancies are responsible for the interaction of vacancies in the atom‐vacancy solid solution. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Metal‐assisted esterification: glutaric acid–iron(II) complexes in the gas phase
Authors: Lee Yong‐III , Jo Sung‐Chan , Tao W. Andy , Cooks R. Graham
Published: August 2002

Transition metal ions are routinely used to assist organic reactions; however, direct detection of the intermediates in such reactions is uncommon. Here, we demonstrate a transition metal ion‐assisted reaction between glutaric acid (L) and methanol, using electrospray ionization mass spectrometry (ESI‐MS). Esterification of glutaric acid does not occur in aqueous methanol solution under ESI conditions, but the FeII‐bound acid cluster, [FeIIL2 − H]+, adds methanol and dehydrates to give rise to an abundant product ion with a 14 Da increased mass. The occurrence of methyl esterification is supported by collision‐induced dissociation and isotopic labeling data, which indicate that the sequence by which the product ion is generated is loss of water, followed by the addition of methanol. Electrospray ionization conditions, specifically the tube lens offset voltage, strongly affect the reaction efficiency, presumably through control of the dehydration process. Other transition metal ions, such as NiII, ZnII, CoII and CuII, also show distinctive metal‐assisted reactions. Copyright © 2001 John Wiley & Sons, Ltd.
Characterization of sodiated glycerol phosphatidylcholine phospholipids by mass spectrometry
Authors: Domingues Pedro , Domingues M. Rosário M. , Amado Francisco M. L. , Ferrer‐Correia A. J.
Published: August 2002

Fast atom bombardment mass spectrometry in the positive mode was used for the characterization of sodiated glycerol phosphatidylcholines. The relative abundance (RA) of the protonated species is similar to the RA of the sodiated molecular species. The sodiated fragment ion, [M + Na − 59]+, corresponding to the loss of trimethylamine, and other sodiated fragment ions, were also observed. The decomposition of the sodiated molecule is very similar for all the studied glycerol phosphatidylcholines, in which the most abundant ion corresponds to a neutral loss of 59 Da. Upon collision‐induced dissociation (CID) of the [M + Na]+ ion informative ions are formed by the losses of the fatty acids in the sn‐1 and sn‐2 positions. Other major fragment ions of the sodiated molecule result from loss of non‐sodiated and sodiated choline phosphate, [M + Na − 183]+, [M + Na − 184]+· and [M + Na − 205]+, respectively. The main CID fragmentation pathway of the [M + Na − 59]+ ion yields the [M + Na − 183]+ ion, also observed in the CID spectra of the [M + Na]+ molecular ion. Other major fragment ions are [M + Na − 205]+ and the fragment ion at m/z 147. Collisional activation of [M + Na − 205]+ results in charge site remote fragmentation of both fatty acid alkyl chains. The terminal ions of these series of charge remote fragmentations result from loss of part of the R1 or R2 alkyl chain. Other major informative ions correspond to acylium ions. Copyright © 2001 John Wiley & Sons, Ltd.
Liquid chromatography/atmospheric pressure chemical ionization mass spectrometry of terpene lactones in plasma of volunteers dosed with Ginkgo biloba L. extracts
Authors: Mauri Pierluigi , Simonetti Paolo , Gardana Claudio , Minoggio Markus , Morazzoni Paolo , Bombardelli Ezio , Pietta Piergiorgio
Published: August 2002

Liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (LC/APCI‐ITMS) was applied to evaluate the levels of ginkgolides A and B and bilobalide in plasma of volunteers after administration of Ginkgo biloba extracts in free (Ginkgoselect®) or phospholipid complex (Ginkgoselect® Phytosome®) forms, providing 9.6 mg of total terpene lactones. The maximum plasma concentrations, Cmax, of total ginkgolides A, B and bilobalide were 85.0 and 181.8 µg/mL for Ginkgoselect and Ginkgoselect Phytosome, respectively. The Cmax values were reached at 120 min for the free form and at 180–240 min for the phospholipid complex form. In both cases, the mean elimination half‐life of each terpene lactone was in the range 120–180 min. Due to its sensitivity (about 1 ng/mL) and specificity, LC/APCI‐ITMS proved to be a very powerful tool for pharmacokinetic studies of these phytochemicals. Copyright © 2001 John Wiley & Sons, Ltd.
Error magnification factors in the isotopic analysis of oxygen as O: possibility of determining true isotopic abundance ratios
Authors: Datta B. P.
Published: August 2002

The simultaneous determination of the 17O/16O abundance ratio (Y) and 18O/16O ratio (Z) as $\hbox{\bf O}_{\bf2}^{+}$ is carried out by solving a set of equations:

where Ri's are the measured abundance ratios of chosen pairs (say, j and k) of isotopic $\hbox{\bf O}_{\bf 2}^{+}$ ions. The measured ratios (Rj and Rk) are always subject to some errors (δj and δk), and hence the corresponding results of analysis (solutions: Y and Z) will inevitably be at errors (δY and δZ). Recently, we have shown that the errors δY and δZ are always expected to be different from those of the experimental errors δj and δk, and are correlated as:

where the parameter $\hbox{\bf[REMF]}_{\bf jk}^{\bf E}$ is referred to as the relative error magnification factor of analysis. This work investigates the parameters $\hbox{\bf[REMF]}_{\bf jk}^{\bf Y}$ and $\hbox{\bf[REMF]}_{\bf jk}^{\bf Z}$ (the error magnification factors in determining the oxygen isotopic ratios, Y and Z simultaneously, as $\hbox{\bf O}_{\bf 2}^{+}$), which control, for any given values of δj and δk, the achievable accuracy of the desired results (determined values of Y and Z). The variations of the REMFs as a function of the choice of isotopic molecular pairs j and k, and/or some other parameters, are evaluated and presented.

The studies predict that although, depending on different possible parameters of analysis, the REMFs can have any values between 0 and (almost) ∞, it should not be at all difficult in case of a real analysis to pre‐select the analytical conditions so that the REMFs take roughly the desired values (i.e. ≤1). It is shown further that, compared to some other molecular species of oxygen such as the $\hbox{\bf CO}_{\bf 2}^{+}$ ions which are more commonly used than the $\hbox{\bf O}_{\bf2}^{+}$ ions themselves as the monitor species for the isotopic analysis of oxygen, the $\hbox{\bf O}_{\bf 2}^{+}$ ions have better properties as the required monitors ions (i.e. $\{\hbox{\bf [REMF]}_{{\bf O}_{2}^{+}}^{\bf E}\} < \{\hbox{\bf [REMF]}_{{\bf CO}_{\bf 2}^{+}}^{\bf E}\}$). Also, choice of the $\hbox{\bf O}_{\bf 2}^{+}$ ions as the monitors (j and k) is expected to yield results close to the true isotopic composition of the analyte oxygen, i.e. it is predicted to be possible in practice to achieve both $\hbox{\bf [REMF]}_{{\bf O}_{\bf 2}^{+}}^{\rm Y}$ and $\hbox{\bf [REMF]}_{{\bf O}_{\bf2}^{+}}^{\bf Z}$ substantially less than unity. Copyright © 2001 John Wiley & Sons, Ltd.
Kinematic design of a humanoid robot wrist
Authors: Schäfer Christian , Dillmann Rüdiger
Published: August 2002

In this paper, a new kinematic model of the human wrist is developed and compared to existing robot wrists. A
detailed analysis of the motion of the involved carpus bones indicates the position and orientation of the motion
axes. Approximations are made to approach a technical feasible model, on the one hand, but to preserve functional
characteristics on the other hand. For the mathematical description, screw theory and the
product‐of‐exponentials method are applied. Characteristic parameters of the model are identified and
quantitative values for a typical person proposed. Finally, similarities between existing robot wrists and the
model are discussed. © 2001 John Wiley & Sons, Inc.
Analysis of random LC tries
Authors: Devroye Luc
Published: August 2002

LC tries were introduced by Andersson and Nilsson in 1993. They are compacted versions of tries or patricia tries in which, from the top down, maximal height complete subtrees are level compressed. Andersson and Nilsson (1993) showed that for i.i.d. uniformly distributed input strings, the expected depth of the LC patricia trie is Θ(log* n). In this article, we refine and extend this result. We analyze both kinds of LC tries for the uniform model, and study the depth of a typical node and the height Hn. For example, we show that Hn is in probability asymptotic to log2 n and \documentclass{article}\pagestyle{empty}\begin{document}$\sqrt{2 \log_2 n}$\end{document} for the LC trie and the LC patricia trie, respectively, and that for both the tries, the depth of a typical node is asymptotic to log*(n) in probability and in expectation. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 19: 359–375, 2001
Noncrossing trees are almost conditioned Galton–Watson trees
Authors: Marckert Jean‐François , Panholzer Alois
Published: August 2002

A noncrossing tree (NC‐tree) is a tree drawn on the plane having as vertices a set of points on the boundary of a circle, and whose edges are straight line segments that do not cross. In this article, we show that NC‐trees with size n are conditioned Galton–Watson trees. As corollaries, we give the limit law of depth‐first traversal processes and the limit profile of NC‐trees. © 2002 John Wiley & Sons, Inc. Random Struct. Alg., 20, 115–125, 2002
Reform Japanese style: Voyage into an unknown and chaotic future
Authors: Ogawa Masakata
Published: August 2002

This article critically examines the ongoing revisions of school education in Japan in general, and of science education and science teacher education in particular. One of the major issues is that the revision policy does not necessarily reflect another emergent national policy, namely: “science and technology as Japan's survival strategy.” The reasons why such a discrepancy between two national policies has happened are investigated from sociocultural viewpoints. The policymakers realize that the school education system in Japan is now in a crisis, as almost all social institutions of traditional Japan society—family, rural communities, and schools—are collapsing, and their educational roles and functions are being lost. Thus, the top priority in the revision of school education is how to recover such educational roles and functions within school settings. So far, the revisions in science education have been unsatisfactory. © 2001 John Wiley & Sons, Inc. Sci Ed 85:586–606, 2001.
A layout adjustment problem for disjoint rectangles preserving orthogonal order
Authors: Hayashi Kunihiko , Inoue Michiko , Masuzawa Toshimitsu , Fujiwara Hideo
Published: August 2002

This study considers a set of n rectangles arranged on a plane, and, in particular, the problem of modifying the initial layout within a minimum area while meeting certain conditions, namely, preservation of orthogonal order and prevention of intersection between rectangles. A heuristic algorithm for this problem with O(n2) complexity was proposed by Misue and colleagues. First, the problem of minimum‐area layout adjustment is shown to be NP‐complete. Then, another heuristic algorithm is examined that results in smaller layout area than that of Misue and colleagues. Using computational experiments with random initial layouts, the proposed algorithm is proven to require 15 to 20% of the area required by the Misue algorithm, especially with a large number of rectangles. © 2002 Scripta Technica, Syst Comp Jpn, 33(2): 31–42, 2002
Constrained sintering of glass, glass–ceramic and ceramic coatings on metal substrates
Authors: Calata Jesus Noel , Lu Guo‐Quan , Chuang Tze‐Jer
Published: August 2002

Many applications now use different materials that are fabricated into structures to obtain the desired combination of properties or to suit particular needs. Ceramics and glasses often are combined with metallic materials for applications in the field of electronics, for insulation and chemical resistance and for improved structural performance such as in composites. One common method of fabricating such structures is by firing coatings and films onto substrates. To obtain usable and reliable components several issues need to be addressed. Two of them—the effect of constraint on the densification and interfacial adhesion—are addressed in this paper. Measurements of densification of some glasses and ceramics showed that the densification rate is reduced by substrate constraint and the effect is more pronounced on crystalline materials than glass. Good adhesion between the coatings and metal substrates also required modifications to the substrate surface to enhance bonding. For coatings sintered onto substrates, such modifications resulted in better bonding. Good adhesion between borosilicate glass and stainless steel was obtained by roughening and preoxidation of the substrate. A very strong adhesion also was obtained between cordierite glass–ceramic and molybdenum substrate after depositing chromium/nickel or chromium/copper layers on the substrate as adhesion layers before coating. Copyright © 2001 John Wiley & Sons, Ltd.