bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma modification of PTFE surfaces. Part I: Surfaces immediately following plasma treatment
Authors: Wilson D. J. , Williams R. L. , Pond R. C. 
Published: September 2002

AbstractPolytetrafluoroethylene (PTFE) was treated in a low‐power plasma using a series of feed gases (O2, Ar, N2 and NH3) and the resulting surface modifications were evaluated by x‐ray photoelectron spectroscopy, static secondary ion mass spectroscopy, dynamic contact angle measurements and atomic force microscopy. All plasma treatments caused light etching, but the nature and extent of chemical modification varied considerably. Fluorine depletion of the surface was affected most efficiently by Ar and least effectively by O2 plasma. New functionalities were introduced to the surface either from plasma derivatives of the feed gases or by post‐treatment exposure to moist air; Ar, N2 and NH3 were more effective than O2 in this respect. The wettability of virgin and plasma‐treated materials in phosphate‐buffered saline solution (PBS) and 1‐bromonaphthalene was studied, and the observations are discussed in a framework that correlates contact‐angle hysteresis with surface chemistry in a semi‐quantitative manner. In Part II of this work, further changes of the surface chemistry and wettability of virgin and plasma‐treated materials arising due to storage in PBS or air are described. Copyright © 2001 John Wiley & Sons, Ltd.
On the cultural validity of science assessments
Authors: Solano‐Flores Guillermo , Nelson‐Barber Sharon 
Published: September 2002

AbstractWe propose the concept of cultural validity as a form of test validity in science assessment. The conceptual relevance of cultural validity is supported by evidence that culture and society shape an individual's mind and thinking. To attain cultural validity, the process of assessment development must consider how the sociocultural context in which students live influences the ways in which they make sense of science items and the ways in which they solve them. These sociocultural influences include the values, beliefs, experiences, communication patterns, teaching and learning styles, and epistemologies inherent in the students' cultural backgrounds, as well as the socioeconomic conditions prevailing in their cultural groups. We contend that current approaches to handling student diversity in assessment (e.g., adapting or translating tests, providing assessment accommodations, estimating test cultural bias) are limited and lack sociocultural perspective. We find that attaining cultural validity may conflict with current basic principles and assumptions in testing, such as item independence and standardization. We discuss the ways in which adopting cultural validity as a criterion for test validity makes it necessary to shift assessment paradigms and adopt new procedures for assessment development. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 553–573, 2001
Interactions of histamine and bradykinin on polymodal C‐fibres in isolated rat skin
Authors: Koppert Wolfgang , Martus Peter , Reeh Peter W. 
Published: September 2002

Patients suffering from pruritus due to atopic dermatitis show, in asymptomatic skin, reduced itch and flare responses to histamine, the major pruritogenic mediator. We hypothesized that this apparent loss in histamine sensitivity may be overcompensated in inflamed skin and investigated the interactions between histamine and bradykinin, the major inflammatory mediator.The studies were performed using the isolated rat skin–nerve preparation. Forty‐two fibres were tested following four different experimental protocols. After characterization of the sensory properties, six fibres were treated repetitively with histamine (HIS1, HIS2) to exclude the possibility that the responses (spikes/min) increase simply by repetition. In 12 other units, histamine (HIS1) was followed by a wash‐out period prior to bradykinin (BK) stimulation; in another 12 units, BK followed immediately after HIS1. A further 12 fibres were examined without preceding heat stimulation in order to avoid possible sensitization.If BK was administered after a wash‐out period following HIS1, the BK responses were significantly higher than the HIS1 response. The BK response showed a peak discharge which was absent if BK followed directly upon HIS1. If HIS2 was applied directly following BK, the induced discharge was significantly larger than the first histamine response and not different from the BK response, whereas a washout period before HIS2 abolished the sensitizing effect of previous BK.A unidirectional sensitization by previous bradykinin or heat stimulation on the histamine responsiveness of polymodal nociceptors has been demonstrated. If ‘itch fibres’ in humans were subject to similar interactions of histamine with inflammatory mediators, this may compensate for a down‐regulation of histamine receptors in eczematic skin and possibly account for the pruritus.
Ontology of Culture and the Study of Human Behavior
Authors: Pyysiäinen Ilkka 
Published: September 2002

AbstractIt is here argued that 'culture' is a universal in the philosophical sense of the term: it expresses a general property. It is not a singular term naming an abstract entity, but rather a singular predicate the intension of which is 'cultureness.' Popper's view of the ontology of mathematics is used as an analogous example in the light of which the ontology of culture is analyzed. Cultures do not have an independent existence (realism), they are not mere names (Nominalism), and neither do they exist as fixed entities in the mind (conceptualism). Cultures are abstractions made by the mind, which yet are not reducible to the mind. They exist in the form of certain mental operations creating a new level of reality. Scientific study of culture involves both explaining how cultural phenomena are constructed in minds and how these constructions function in cognition and communication.
Sliding–window neural state estimation in a power plant heater line
Authors: Alessandri A. , Parisini T. , Zoppoli R. 
Published: September 2002

AbstractThe state estimation problem for a section of a real power plant is addressed by means of a recently proposed sliding‐window neural state estimator. The complexity and the nonlinearity of the considered application prevent us from successfully using standard techniques as Kalman filtering. The statistics of the distribution of the initial state and of noises are assumed to be unknown and the estimator is designed by minimizing a given generalized least‐squares cost function. The following approximations are enforced: (i) the state estimator is a finite‐memory one, (ii) the estimation functions are given fixed structures in which a certain number of parameters have to be optimized (multilayer feedforward neural networks are chosen from among various possible nonlinear approximators), (iii) the algorithms for optimizing the parameters (i.e., the network weights) rely on a stochastic approximation. Extensive simulation results on a complex model of a part of a real power plant are reported to compare the behaviour of the proposed estimator with the extended Kalman filter. Copyright © 2001 John Wiley & Sons, Ltd.
Neural network adaptive robust control with application to precision motion control of linear motors
Authors: Gong J. Q. , Yao Bin 
Published: September 2002

AbstractIn this paper, neural networks (NNs) and adaptive robust control (ARC) design philosophy are integrated to design performance‐oriented control laws for a class of single‐input–single‐output (SISO)nth‐order non‐ linear systems. Both repeatable (or state dependent) unknown non‐linearities and non‐repeatable unknown non‐linearities such as external disturbances are considered. In addition, unknown non‐linearities can exist in the control input channel as well. All unknown but repeatable non‐linear functions are approximated by outputs of multi‐layer neural networks to achieve a better model compensation for an improved performance. All NN weights are tuned on‐line with no prior training needed. In order to avoid the possible divergence of the on‐line tuning of neural network, discontinuous projection method with fictitious bounds is used in the NN weight adjusting laws to make sure that all NN weights are tuned within a prescribed range. By doing so, even in the presence of approximation error and non‐repeatable non‐linearities such as disturbances, a controlled learning is achieved and the possible destabilizing effect of on‐line tuning of NN weights is avoided. Certain robust control terms are constructed to attenuate various model uncertainties effectively for a guaranteed output tracking transient performance and a guaranteed final tracking accuracy in general. In addition, if the unknown repeatable model uncertainties are in the functional range of the neural networks and the ideal weights fall within the prescribed range, asymptotic output tracking is also achieved to retain the perfect learning capability of neural networks in the ideal situation. The proposed neural network adaptive control (NNARC) strategy is then applied to the precision motion control of a linear motor drive system to help to realize the high‐performance potential of such a drive technology. NN is employed to compensate for the effects of the lumped unknown non‐linearities due to the position dependent friction and electro‐magnetic ripple forces. Comparative experiments verify the high‐performance nature of the proposed NNARC. With an encoder resolution of 1 µm, for a low‐speed back‐and‐forth movement, the position tracking error is kept within ±2 µm during the most execution time while the maximum tracking error during the entire run is kept within ±5.6 µm. Copyright © 2001 John Wiley & Sons, Ltd.
Strategic response to mandatory reporting legislation in the U.S. livestock and meat industries: Are collusive opportunities enhanced?
Authors: Wachenheim Cheryl J. , DeVuyst Eric A. 
Published: September 2002

AbstractRecent federal legislation requires U.S. meat packers to report detailed information about livestock and meat transactions. The goal of this legislation is to improve competitiveness within the livestock sector and improve decision making within the marketing channel. We discuss the effect of industry structure and market transaction information on the competitive behavior of participant firms and why this legislation may actually reduce the price paid to livestock producers. [JEL Classification: L100, L110, L120] © 2001 John Wiley & Sons, Inc.
Diachronic patterns of dental hypoplasias and vault porosities during the predynastic in the Naqada region, Upper Egypt
Authors: Keita S.O.Y. , Boyce A.J. 
Published: September 2002

AbstractThe diachronic pattern of the frequencies of linear enamel hypoplasias and porotic hyperostosis was studied in temporally separated samples of adult predynastic Egyptian remains from the Naqada region, Upper Egypt. The samples covered a period of increasing population density and social complexity as well as decreasing Nile flooding in Egypt. First and second molars were evaluated for hypoplasias in material from the Naqada I, II, and III periods; sample sizes were 13, 30, and 25, respectively, for the first molar, and 11, 28, and 24 for the second molar. Cranial vaults were examined for porotic hyperostosis using several approaches; sample sizes were 26, 66, and 51 for Naqada I, II and III, respectively. Linear regression showed a decreasing trend for several variables: for the individual frequency of first molar hypoplasias (ρ = 0.025), the vault porosity score, which indicates the severity of the lesions (ρ < 0.001), and the extent score, which indicates the number of superior vault bones having porosities (ρ < 0.001). Logistic regression showed a temporal decline in the percentage of crania per sample having any vault porosities and only higher grade lesions (ρ < 0.012 and ρ < 0.003, respectively). Lesions of the second molar showed no directional trend. The results contrast with the common observation that these skeletal markers usually increase in contexts of increasing population density and social complexity. Am. J. Hum. Biol. 13:733–743, 2001. © 2001 Wiley‐Liss, Inc.
A case‐control study of the relationship between the risk of colon cancer in men and exposures to occupational agents
Authors: Goldberg Mark S. , Parent Marie‐Élise , Siemiatycki Jack , Désy Marie , Nadon Louise , Richardson Lesley , Lakhani Ramzan , Latreille Benoit , Valois Marie‐France 
Published: September 2002

AbstractBackgroundWe conducted a population‐based case‐control study in Montreal, Canada, to explore associations between hundreds of occupational circumstances and several cancer sites, including colon.MethodsWe interviewed 497 male patients with a pathologically confirmed diagnosis of colon cancer, 1514 controls with cancers at other sites, and 533 population‐based controls. Detailed job histories and relevant potential confounding variables were obtained, and the job histories were translated by a team of chemists and industrial hygienists into a history of occupational exposures.ResultsWe found that there was reasonable evidence of associations for men employed in nine industry groups (adjusted odds ranging from 1.1 to 1.6 per a 10‐year increase in duration of employment), and in 12 job groups (OR varying from 1.1 to 1.7). In addition, we found evidence of increased risks by increasing level of exposures to 21 occupational agents, including polystyrene (OR for “substantial” exposure (ORsubst) = 10.7), polyurethanes (ORsubst = 8.4), coke dust (ORsubst = 5.6), mineral oils (ORsubst = 3.3), polyacrylates (ORsubst = 2.8), cellulose nitrate (ORsubst = 2.6), alkyds (ORsubst = 2.5), inorganic insulation dust (ORsubst = 2.3), plastic dusts (ORsubst = 2.3), asbestos (ORsubst = 2.1), mineral wool fibers (ORsubst = 2.1), glass fibers (ORsubst = 2.0), iron oxides (ORsubst = 1.9), aliphatic ketones (ORsubst = 1.9), benzene (ORsubst = 1.9), xylene (ORsubst = 1.9), inorganic acid solutions (ORsubst = 1.8), waxes, polishes (ORsubst = 1.8), mononuclear aromatic hydrocarbons (ORsubst = 1.6), toluene (ORsubst = 1.6), and diesel engine emissions (ORsubst = 1.5). Not all of these effects are independent because some exposures occurred contemporaneously with others or because they referred to a group of substances.ConclusionsWe have uncovered a number of occupational associations with colon cancer. For most of these agents, there are no published data to support or refute our observations. As there are few accepted risk factors for colon cancer, we suggest that new occupational and toxicologic studies be undertaken focusing on the more prevalent substances reported herein. Am. J. Ind. Med. 39:531–546, 2001. © 2001 Wiley‐Liss, Inc.
Subspecific genetic differences in the saddle‐back tamarin (Saguinus fuscicollis) postcranial skeleton
Authors: Kohn Luci Ann P. , Langton Laura Bishoff , Cheverud James M. 
Published: September 2002

AbstractSaddle‐back tamarins (Saguinus fuscicollis) have been differentiated into subspecies based on coat color and facial morphology. Morphology of first‐generation genetic hybrids can provide an understanding of population differences and evolution that may otherwise be difficult to obtain. This study compares postcranial morphology in two hybrids of saddle‐back tamarins (S. f. illigeri × S. f. lagonotus and S. f. illigeri × S. f. leucogenys) to the purebred subspecies. We examine whether postcranial morphology differs between the purebred subspecies and their hybrids, and whether hybrids exhibit heterosis indicative of genetic differences between the parental subspecies. Fifty postcranial dimensions, or traits, were measured on 287 S. fuscicollis skeletons. Measurements were corrected for sex differences and environmental differences (wild‐derived or laboratory‐born). Females were larger than males for most postcranial dimensions, especially in the pelvis. Significant environmental differences were found throughout the postcranial skeleton, with wild‐derived animals generally larger than animals born in the laboratory. Significant heterosis was found for six postcranial traits in the S. f. illigeri × S. f. leucogenys cross, and heterosis was found for 15 postcranial traits in the S. f. illigeri × S. f. lagonotus cross. These results suggest that subspecies differences in skeletal morphology are generally due to genetic rather than environmental differences. The subspecies appear to represent geographic isolates that differ in gene frequencies and directional dominance for skeletal traits. Am. J. Primatol. 54:41–56, 2001. © 2001 Wiley‐Liss, Inc.
Individual variation in the growth of captive infant gorillas
Authors: Bellisari Anna , Newman Timothy K. , Greenberg Chandra , Rogers Jeffrey , Towne Bradford 
Published: September 2002

AbstractSerial anthropometric data were obtained during the first year of life of six nursery‐reared infant gorillas in the Columbus (Ohio) Zoo. Two of the infants are likely to be monozygotic twins as determined by DNA analysis. Growth curves were fitted to serial measures of cephalo‐thoracic‐abdominal length, arm length, leg length, head circumference, upper arm circumference, and weight from each gorilla, to describe individual patterns of variation in skeletal growth and body composition. Growth in skeletal measures tended to be curvilinear to varying degrees over the first year of life. Body composition varied more than skeletal measures throughout the first year as a consequence of individual health status. Individual growth and body composition variations appear to reflect both genetic and environmental influences in this small sample of captive infant gorillas. Am J Phys Anthropol 115:110–132, 2001. © 2001 Wiley‐Liss, Inc.
Presumed pre‐ or perinatal arterial ischemic stroke: Risk factors and outcomes
Authors: Golomb Meredith R. , MacGregor Daune L. , Domi Trish , Armstrong Derek C. , McCrindle Brian W. , Mayank Supriya , DeVeber Gabrielle A. 
Published: September 2002

AbstractA subgroup of children with arterial ischemic stroke in the pre‐ or perinatal period present with delayed diagnosis. We identified 22 children who met the following criteria: (1) normal neonatal neurological history, (2) hemiparesis and/or seizures first recognized after 2 months of age, and (3) computed tomography or magnetic resonance imaging showing remote cerebral infarct. Laboratory evaluations included protein C, protein S, antithrombin, activated protein C resistance screen (APCR), Factor V Leiden (FVL), prothrombin gene defect, methylene tetrahydrofolate reductase variant (MTHFR), anticardiolipin antibody (ACLA), and lupus anticoagulant. Not all children received all tests. Age at last visit ranged from 8 months to 16.5 years (median 4 years). Twelve were boys. Fourteen had left hemisphere infarcts. Median age at presentation was 6 months. Eighteen had gestational complications. Fourteen children had at least transient coagulation abnormalities (ACLA = 11, ACLA + APCR = 1, APCR = 2 with FVL + MTHFR = 1); 6 of these children had family histories suggestive of thrombosis. Cardiac echocardiogram was unremarkable in the 15 tested. Outcomes included persistent hemiparesis in 22; speech, behavior, or learning problems in 12; and persistent seizures in 5, with no evidence of further stroke in any patient. The persistence and importance of coagulation abnormalities in this group need further study.
Proton magnetic resonance spectroscopy of brain metabolites in galactosemia
Authors: Wang Zhiyue J. , Berry Gerard T. , Dreha Steffi F. , Zhao Huaqing , Segal Stanton , Zimmerman Robert A. 
Published: September 2002

AbstractBrain edema may occur in infants with galactosemia and has been associated with accumulation of galactitol. Proton magnetic resonance spectra were obtained from 12 patients (four newly diagnosed neonates and eight patients on galactose‐restricted diets, age range 1.7–47 years) and control subjects to measure brain galactitol levels in vivo and correlate them with urinary galactitol excretion. The results demonstrate that a markedly elevated brain galactitol level may be present only in newborn infants with galactosemia who exhibit massive urinary galactitol excretion.
Patterned nanostructured arrays for high‐density magnetic recording
Authors: Tofail S. A. M. , Rahman I. Z. , Rahman M. A. 
Published: September 2002

AbstractThis article reviews the recent advances in patterned magnetic nanostructures for application in high‐density recording. In this connection we discuss: (1) the fundamental limits of magnetic recording on conventional magnetic disks and the need for newer materials; (2) the state‐of‐the art technology for creating arrays of magnetic nanostructures; and (3) prospects and problems of high‐ or ultrahigh‐density recording using these nanostructured arrays. Copyright © 2001 John Wiley & Sons, Ltd.
Sorption of tributyltin in seawater by municipal solid waste compost
Authors: Vassallo Ruth , Vella Alfred J. 
Published: September 2002

AbstractThe use of municipal solid waste (MSW) compost as a sorbent for tributyltin (TBT) in seawater was investigated. TBT‐contaminated seawater, both artificially prepared and that collected from Msida Creek yacht marina (Malta), was allowed to percolate through untreated and water‐washed columns of compost and then analysed for organotins using gas chromatography‐flame photometric detection. About 90% of dissolved TBT ranging in concentration from about 800 to 8000 ngSnl−1 was sorbed by treating 500 ml solutions with 100 g untreated compost. On the other hand, no detectable breakthrough of TBT was observed from compost that had previously been washed by water to remove soluble organic matter. Breakthrough of TBT from unwashed compost is thought to be due to formation of complexes between the soluble organic matter in compost and aquated TBT, which renders the organotin more hydrophilic. The use of washed MSW compost as sorbent for the purification of TBT‐contaminated waters generated in large quantity during hull‐cleaning activities in drydocks is suggested as a mitigatory measure against the impact of TBT on the coastal marine environment. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and biological study of a new series of bifunctional organoiron thio‐ and seleno‐terephthalate derivatives (C5H5)Fe(CO)2ECO(C6H4)COX (E = S, X = R2N, RNH, NH2, OH, Cl; E = Se, X = RNH, RS, RCOO, NH2, OH, Cl)
Authors: Maslat Ahmed O. , Jibril Ibrahim , Abussaud Mahmoud , Abd‐Alhadi Emad H. , Hamadah Zuhair 
Published: September 2002

AbstractA new series of bifunctional organoiron thio‐ and seleno‐terephthalate complexes — (η‐C5H5)Fe(CO)2ECO(C6H4)COX [E = S; X = C6H11NH, (C2H5)2N; and E = Se; X = PCH3C6H4NH, C6H5C2N2OS, mNO2C6H4CHCHCOO] — has been synthesized via the organic transformation reactions of the terephthaloyl chloride precursors η‐(C5H5)Fe(CO)2ECO(C6H4)COCl with the desired nucleophiles. These new complexes were characterized by elemental analysis, IR and 1H NMR spectra. The above complexes, in addition to some other selected analogues, were tested for their antifungal, antibacterial and mutagenic activity. Our results show that all the selenium‐containing compounds have antifungal activity on Candida albicans and antibacterial effects against Bacillus subtilis and Staphylococcus aureus. Four of the six selenium‐containing derivatives exhibited growth inhibitory effects against Pseudomonas aeruginosa and/or Escherichia coli. Sulfur‐containing derivatives elicited activity against C. albicans, and each one of them showed activity against at least one of the bacterial strains that have been used in this investigation. Two selenium‐ and two sulfur‐containing derivatives showed mutagenic activity against one or more than one strain of the Salmonella typhimurium using the Ames test. Copyright © 2001 John Wiley & Sons, Ltd.