bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coding‐theoretic constructions for (t,m,s)‐nets and ordered orthogonal arrays
Authors: Bierbrauer Jürgen , Edel Yves , Schmid Wolfgang Ch. 
Published: October 2002

Abstract(t,m,s)‐nets are point sets in Euclidean s‐space satisfying certain uniformity conditions, for use in numerical integration. They can be equivalently described in terms of ordered orthogonal arrays, a class of finite geometrical structures generalizing orthogonal arrays. This establishes a link between quasi‐Monte Carlo methods and coding theory. The ambient space is a metric space generalizing the Hamming space of coding theory. We denote it by NRT space (named after Niederreiter, Rosenbloom and Tsfasman). Our main results are generalizations of coding‐theoretic constructions from Hamming space to NRT space. These comprise a version of the Gilbert‐Varshamov bound, the (u,u+υ)‐construction and concatenation. We present a table of the best known parameters of q‐ary (t,m,s)‐nets for qε{2,3,4,5} and dimension m≤50. © 2002 Wiley Periodicals, Inc. J Combin Designs 10: 403–418, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10015
Introduction: Reprioritizing the role of science in a realistic version of the scientist‐practitioner model
Authors: Lampropoulos Georgios K. , Spengler Paul M. 
Published: October 2002

AbstractThis series of articles attempts to redefine and reprioritize the role of science in search for a clinically meaningful and realistic version of the scientist‐practitioner (S‐P) model. To this end, science is discussed as both research‐driven practice and clinically meaningful research, keeping practitioners and their needs in the center of attention. In this process, common problems in the actualization of the S‐P model are discussed, and potential solutions are offered. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 1195–1197, 2002.
Oxidative stress: the role of cytochromes P450 in oxygen activation
Authors: Lewis David F V 
Published: October 2002

AbstractOxidative stress is associated with a number of degenerative disease states, such as cancer and AIDS. Fundamental to oxidative stress is the generation of superoxide, peroxide and other reactive oxygen species (ROS). This review focuses on the importance of cytochrome P450 (CYP) enzymes in the activation of oxygen and ROS generation, together with a discussion of defence mechanisms which can offer protection against oxidative stress.© 2002 Society of Chemical Industry.
Treatment of wastewater containing copper, zinc, nickel and cobalt using Duolite ES‐467
Authors: Srinivasa Rao K , Sarangi D , Dash P K , Chaudhury G Roy 
Published: October 2002

AbstractDuolite ES‐467 was used to treat wastewater containing heavy metal ions. Sorption experiments were carried out at varying pH values, agitation speeds, reaction times, and metal ion and sorbent concentrations. Each of the parameters affects the sorption behaviour of individual metal ions. Copper sorption was greater compared with other metal ions such as zinc, nickel and cobalt. The presence of other metal ions affects copper sorption. Equilibrium isotherm curves were developed. These were used to predict that the metal ion concentration would be reduced from 100 to less than 1 mg dm−3. Fixed bed tests were conducted to investigate the efficiency of Duolite ES‐467 for the selective removal of copper ions from multi‐metal solutions. Breakthrough curves were obtained using Duolite ES‐467 for solutions containing copper, nickel and copper, zinc, nickel and cobalt. Elution studies were also carried out using sulfuric acid.© 2002 Society of Chemical Industry
Pigment pattern formation in zebrafish: A model for developmental genetics and the evolution of form
Authors: Quigley Ian K. , Parichy David M. 
Published: October 2002

AbstractThe zebrafish Danio rerio is an emerging model organism for understanding vertebrate development and genetics. One trait of both historical and recent interest is the pattern formed by neural crest–derived pigment cells, or chromatophores, which include black melanophores, yellow xanthophores, and iridescent iridophores. In zebrafish, an embryonic and early larval pigment pattern consists of several stripes of melanophores and iridophores, whereas xanthophores are scattered widely over the flank. During metamorphosis, however, this pattern is transformed into that of the adult, which comprises several dark stripes of melanophores and iridophores that alternate with light stripes of xanthophores and iridophores. In this review, we place zebrafish relative to other model and non‐model species; we review what is known about the processes of chromatophore specification, differentiation, and morphogenesis during the development of embryonic and adult pigment patterns, and we address how future studies of zebrafish will likely aid our understanding of human disease and the evolution of form. Microsc. Res. Tech. 58:442–455, 2002. © 2002 Wiley‐Liss, Inc.
How trematodes cause limb deformities in amphibians
Authors: Stopper Geffrey F. , Hecker Louise , Franssen R. Adam , Sessions Stanley K. 
Published: October 2002

AbstractWe used trematode cyst infestation to induce limb deformities in two species of frogs of the genus Rana and compared them to deformities induced by surgical limb bud rotations. The specific deformities produced by both treatments closely resemble those of wild‐caught deformed amphibians and are consistent with a known developmental response to disruption of the spatial organization of cells in developing limb buds. Histological analysis showed that trematode cysts cause massive disruption and abnormal cellular growth involving the limb buds of infected individuals. Our results indicate that trematode cyst infestation causes deformities in frogs by perturbation of the positional relationships of cells in developing limb buds. The crippling effects of cyst‐infection on frogs may reflect complex co‐evolutionary interactions among trematodes, frogs, and other hosts in the trematode's life cycle. J. Exp. Zool. (Mol. Dev. Evol.) 294:252–263, 2002. © 2002 Wiley‐Liss, Inc.
How do ants stick out their tongues?
Authors: Paul Jürgen , Roces Flavio , Hölldobler Bert 
Published: October 2002

AbstractThe mouthparts are very important tools for almost any task performed by ants. In particular, the labiomaxillary complex is essential for food intake. In the present study we investigated the anatomical design of the labiomaxillary complex in various ant species, focusing on movement mechanisms. Six labial and six maxillary muscles with different functions control the several joints and ensure the proper performance of the labiomaxillary complex. According to our measurements of sarcomere lengths, muscle fiber lengths and diameters, and the relative muscle volumes, the labial and maxillary muscles feature rather slow than fast muscle characteristics and do not seem to be specialized for specific tasks. Since glossa protractor muscles are absent, the protraction of the glossa, the distal end of the labium, is a nonmuscular movement. By histological measurements of hemolymph volumes we could exclude a pressure‐driven mechanism. Additional experiments showed that, upon relaxation of the glossa retractor muscles, the glossa protracts elastically. This elastic mechanism possibly sets an upper limit to licking frequency, thus influencing food intake rates and ultimately foraging behavior. In contrast to many other elastic mechanisms among arthropods, glossa protraction in ants is based on a mechanism where elasticity works as an actual antagonist to muscles. We compared the design of the labiomaxillary complex of ants with that of the honeybee and suggest an elastic mechanism for glossa protraction in honeybees as well. J. Morphol. 254:39–52, 2002. © 2002 Wiley‐Liss, Inc.
Novel bridge of axon‐like processes of epithelial cells in the aboral sense organ of ctenophores
Authors: Tamm Sidney L. , Tamm Signhild 
Published: October 2002

AbstractWe describe by light and electron microscopy a novel structure in the aboral sense organ (apical organ) of cydippid (Pleurobrachia) and lobate (Mnemiopsis) ctenophores. An elevated bundle of long, thin, microtubule‐filled processes arises from the apical ends of two groups of epithelial cells located on opposite sides of the apical organ along the tentacular plane of the body. This bundle of axon‐like processes arches over the epithelial floor like a bridge, with branches at both ends running toward opposing pairs of ciliary balancers that are motile pacemakers for the rows of locomotory ciliary comb plates. The bridge in Pleurobrachia is ∼40 μm long and 3–4 μm wide and consists of ∼60 closely packed processes, 0.2–0.8 μm thick, containing vesicles and numerous microtubules running parallel to their long axes. There are ∼30 epithelial cells in each of the two groups giving rise to the bridge and each cell forms a single process, so roughly half of the processes in the bridge must originate from cells on one side and diverge into branches to a pair of balancers on the opposite side of the apical organ. The 150–200 cilia in each balancer arise from morphologically complex cellular projections with asymmetric lateral extensions directed towards a fork of the bridge. Presynaptic triad structures and vesicles are found in this region but clear examples of synaptic contacts between bridge processes and balancer cells have not yet been traced. Cydippid larvae of Mnemiopsis have a conspicuous bridge along the tentacular plane of the apical organ. Beroid ctenophores that lack tentacles at all stages do not have a bridge. We discuss the possibility that the bridge is an electrical conduction pathway to balancers that coordinates tentacle‐evoked swimming responses of ctenophores, such as global ciliary excitation. J. Morphol. 254:99–120, 2002. © 2002 Wiley‐Liss, Inc.
Odontode morphology and skin surface features of Andean astroblepid catfishes (Siluriformes, Astroblepidae)
Authors: Schaefer Scott A. , Buitrago‐Suárez Uriel Angel 
Published: October 2002

AbstractTwo types of odontodes, or dermal teeth, occur in the neotropical Andean astroblepid catfishes. Both odontode types conform in structure to dermal teeth of gnathostomes in having dentine surrounding a central pulp cavity covered by a superficial layer of enameloid, but differ from one another in terms of attachment and association with other epidermis features. Type I odontodes in astroblepids, also found in all representatives of the superfamily Loricarioidea, are larger (40–50 μm base diameter), generally conical and sharply pointed, occur on the fin rays, and are associated with dermal bone. Type I odontodes attach to an elevated pediment of dermal bone of the fin lepidotrich, and to dermal bone generally in loricarioids, via a ring of connective tissue. Type II odontodes of astroblepids are smaller (15–20 μm base diameter) and blunt, occur in the skin of the head, maxillary barbels, nasal flap, and lip margins, and are not associated with dermal bone. Observations based on histology and scanning electron microscopy indicate that Type II odontodes are associated with other epithelial structures to form a putative mechanosensory organ. The odontode base lies deep in the dermis. The shaft is surrounded by a dense patch of microvillous epithelium and projects from within a pit formed by an elevated ring of laminar epithelial cells bearing several columnar, knob‐like putative mechanosensory structures. Type II odontode organs have thus far been observed in only three astroblepid species,Astroblepus longifilis, A. chotae, A. rosei, where they occur in especially dense arrays on the maxillary barbels, surrounded by discrete patches of microvilli and separate mechanoreceptors. Type II odontode organs are less dense elsewhere on the body, but also occur in the skin of the snout, head, and lips. Typical taste buds are absent from the barbels of these species, but present in other astroblepids. The presence of Type II odontodes and their association with specialized epithelial pit organs are unique to astroblepids among siluriforms and may be potentially important adaptations to life in torrential mountain streams. J. Morphol. 254:139–148, 2002. © 2002 Wiley‐Liss, Inc.
Functional morphology of the hindlimb of tupaiids (Mammalia, Scandentia) and its phylogenetic implications
Authors: Sargis Eric J. 
Published: October 2002

AbstractIn this study, the hindlimb of 12 species of tupaiids was analyzed functionally and compared to that of primates, dermopterans, and chiropterans. Many aspects of the tupaiid hindlimb vary in relation to differential substrate use. These differences include width of the ilium, shape of the acetabulum, size of the anterior inferior iliac spine, size of the greater and third trochanters, depth of the femoral condyles, shape of the patellar groove, and size of the tibial tuberosity. The hindlimb of the arboreal Ptilocercus lowii, the only ptilocercine, is better adapted for arboreal locomotion, whereas that of tupaiines is better adapted for rapid terrestrial (or scansorial) locomotion. The hindlimb of Ptilocercus seems to be habitually flexed and has more joint mobility, a condition necessary for movement on uneven, discontinuous arboreal supports. The tarsus of Ptilocercus facilitates inversion of the foot and its grasping hallux is capable of a great range of abduction. Tupaiines, on the other hand, are characterized by more extended hindlimbs and less mobility in their joints. These restricted joints limit movements more to the parasagittal plane, which increases the efficiency of locomotion on a more even and continuous surface like the ground. The hindlimb of tupaiines is adapted for powerful flexion and extension. Even the most arboreal tupaiines remain similar to terrestrial tupaiines in their hindlimb morphology, which probably reflects the terrestrial ancestry of Tupaiinae (but not Tupaiidae). Many attributes of the tupaiid hindlimb, especially those of the foot, reflect the arboreal ancestry of Tupaiidae and it is proposed that the ancestral tupaiid was arboreal like Ptilocercus. Also, compared to the hindlimb character states of tupaiines, those of Ptilocercus are more similar to those of other archontans, and it is proposed that the hindlimb features of Ptilocercus are primitive for the Tupaiidae. Hence, Ptilocercus should be considered in any phylogenetic analysis that includes Scandentia. J. Morphol. 254:149–185, 2002. © 2002 Wiley‐Liss, Inc.
Formation of [bn + 17 + Ag]+ product ions from Ag+ cationized native and acetylated peptides
Authors: Anbalagan V. , Perera B. A. , Silva A. T. M. , Gallardo A. L. , Barber M. , Barr J. M. , Terkarli S. M. , Talaty E. R. , Van Stipdonk M. J. 
Published: October 2002

AbstractWe compared the tandem mass spectra of a range of native and acetylated Ag+ cationized peptides to determine the influence of the derivatization step on the abundance of the [bn + 17 + Ag]+ product ions. Using tripeptides, the smallest for which the mechanisms to generate [b2 − 1 + Ag]+ and [b2 + 17 + Ag]+ products are both operative, we found that in most cases acetylation causes an increase in the abundance of the C‐terminal rearrangement ion, [b2 + 17 + Ag]+, relative to the rival N‐terminal rearrangement ion, [b2 − 1 + Ag]+. The presence of a free amino group to bind to the metal ion significantly influences the relative abundances of the product ions. We propose a mechanism for the formation of the [bn + 17 + Ag]+ that is based on the formation of a five‐membered oxazolidin‐5‐one and tetrahedral carbon intermediate that may collapse to a peptide upon release of CO and an imine, aided by the fact that the ring formed during C‐terminal rearrangement is both a hemiacylal and hemiaminal. We also identified an influence of amino acid sequence on the relative abundances of the [bn + 17 + Ag]+ and [bn − 1 + Ag]+ product ions, whereby bulky substituents located on the α‐carbon of the amino acid to the C‐terminal side of the cleavage site apparently promote the formation of the [bn + 17 + Ag]+ product over [bn − 1 + Ag]+ when the amino acid to the N‐terminal side of the cleavage site is glycine. The latter ion is the favored product, however, when the bulky group is positioned on the α‐carbon of the amino acid to the N‐terminal side of the cleavage site. Copyright © 2002 John Wiley & Sons, Ltd.
FDTD design of RF dosimetry apparatus to quantify the effects of near fields from mobile handsets on stress response mechanisms of human whole blood
Authors: Lim H. B. , Cook G. G. , Barker A. T. , Coulton L. A. 
Published: October 2002

AbstractA Crawford transverse electro‐magnetic (TEM) cell, used for RF exposure of in vitrocell cultures to examine any pathological effects, is modelled using an original high resolution finite‐difference time‐domain (FDTD) code at cellular handset frequencies. The standard scalar specific absorption rate (SAR) dosimetry parameter is augmented by new vector parameters of field polarization type and phase, and an easily comprehensible way of displaying these data as polar plots is used. It is shown that whilst the incident field in the empty TEM cell has plane wave properties, the exposure field in a blood sample is not a TEM plane wave, nor is it representative of the near field produced by a mobile handset. It is suggested that the exposure field vector properties need to be quantified and controlled in the TEM cell, and experimentation performed to assess whether there is a differential cellular stress response to these parameters in addition to SAR level. Copyright © 2002 John Wiley & Sons, Ltd.
Model order reduction and equivalent circuit extraction for fit discretized electromagnetic systems
Authors: Wittig Tilmann , Munteanu Irina , Schuhmann Rolf , Weiland Thomas 
Published: October 2002

AbstractIn this paper a new approach for model order reduction of electrodynamic devices discretized by the finite integration theory is presented. It has two main applications: The fast frequency sweep of the transfer behaviour of resonant filters and the extraction of general equivalent circuits simplifying coupled circuit–electromagnetic simulations. The proposed two‐step Lanczos (TSL) algorithm combines a Lanczos based projection in the first step to pre‐reduce the non‐inverted system with a PVL‐like algorithm in the second step to get an optimal Padé approximation. This algorithm drastically reduces the computational complexity of model order reduction while maintaining the same accuracy as direct PVL. By applying it to a curl–curl formulation of the system, the computational cost is further reduced by a factor of two. By use of a projection method the curl–curl formulation can also be extended to lossy systems. Additionally, the method keeps the system stable, passive, and real throughout the process—an important prerequisite for the interpretation of the model as an equivalent network. Copyright © 2002 John Wiley & Sons, Ltd.
Existence of functional β1‐ and β2‐adrenergic receptors on microglia
Authors: Tanaka Kenji F. , Kashima Haruo , Suzuki Hiromi , Ono Kenji , Sawada Makoto 
Published: October 2002

AbstractWe examined the expression and function of β‐adrenergic receptor (β‐AR) subtypes in both isolated primary rat microglia and a rat microglial cell line. RT‐PCR analyses revealed that microglia expressed β1‐ and β2‐ARs but not β3‐ARs, whereas rat primary peritoneal macrophages expressed only β2‐ARs. Stimulation of β‐ARs on microglia by norepinephrine (NE) resulted in an increase in the level of intracellular cAMP and the subsequent expression of interleukin‐1β mRNA. These effects were prevented by propranolol. Similar results were obtained with other selective β1‐AR agonists and antagonists. β2‐ARs on microglia were also functional. It is possible that noradrenergic innervations participate in the control of microglial functions via β1‐ARs on microglia in the brain, because NE has high affinity for β1‐ and β3‐ARs but little or no affinity for β2‐ARs. It seems physiologically significant that microglia can be controlled by NE, which predominates over epinephrine in the brain, whereas macrophages in peripheral tissues can be controlled by epinephrine, which is at higher levels in peripheral tissues. © 2002 Wiley‐Liss, Inc.
Survival of fetal hippocampal CA3 cell grafts in the middle‐aged and aged hippocampus: Effect of host age and deafferentation
Authors: Zaman Vandana , Shetty Ashok K. 
Published: October 2002

AbstractThe potential application of neural transplantation to many neurodegenerative disorders at early stages of disease progression would involve middle‐aged and aged persons. Hence, it is important to examine critically the extent of graft cell survival in both intact and partially deafferented middle‐aged and aged brain. We investigated the degree of survival of 5′‐bromodeoxyuridine (BrdU)‐labeled fetal hippocampal CA3 cells after grafting into both intact hippocampus and partially deafferented hippocampus (i.e., hippocampus contralateral to intracerebroventricular administration of kainic acid) of middle‐aged and aged Fischer 344 rats. Absolute cell survival within these grafts was rigorously analyzed using BrdU immunostaining of serial sections and the optical fractionator cell counting method. In the intact hippocampus, graft cell survival was 23% of injected cells for middle‐aged rats and 18% for aged rats, which is consistent with the survival of fetal hippocampal cells in the intact young adult hippocampus reported earlier (Shetty and Turner [1995] Neuroscience 67:561–582). A partial deafferentation at the time of grafting significantly enhanced the degree of graft cell survival to 35% of injected cells in the middle‐aged hippocampus and 27% in the aged hippocampus. However, the overall graft cell survival after deafferentation was significantly (30%) greater in the middle‐aged hippocampus compared with the aged hippocampus. These results reveal that 1) the degree of survival of fetal neural cells in the intact mature brain remains constant with aging and 2) a partial deafferentation of the mature host brain at the time of grafting enhances survival of grafted fetal cells, regardless of the host age. However, the overall extent of graft cell survival after deafferentation depends on the age of the mature brain at the time of deafferentation. © 2002 Wiley‐Liss, Inc.
Fourier transform Raman and Fourier transform infrared spectra of cross‐linked polyurethaneurea films synthesized from solutions
Authors: Romanova Valentina , Begishev Valery , Karmanov Valery , Kondyurin Alexey , Maitz Manfred F. 
Published: October 2002

AbstractCross‐linked polyurethaneurea films based on polyoxytetramethylene glycol and polyoxypropylene glycol with toluene diisocyanate and 3,3′‐dichloro‐4,4′‐diaminodiphenylmethane were synthesized in a solution where the solvent evaporates during the polymerization. FT‐Raman and FTIR spectra were analysed and intermolecular force constants of hydrogen bonds were calculated. On the basis of the intensity of the Raman and IR spectral lines, which reflects hydrogen bond formation, the optimum structure of hydrogen bonds and the conformations of macromolecules of polyurethaneurea were observed for the solvent ethyl acetate. Copyright © 2002 John Wiley & Sons, Ltd.
Raman spectroscopy of the basic copper chloride minerals atacamite and paratacamite: implications for the study of copper, brass and bronze objects of archaeological significance
Authors: Frost Ray L. , Martens Wayde , Kloprogge J. Theo , Williams Peter A. 
Published: October 2002

AbstractRaman spectra of the basic copper chloride minerals atacamite and paratacamite were obtained at 298 and 77 K using a Raman microprobe in combination with a thermal stage. Four distinct regions involved with hydroxyl stretching, hydroxyl deformation, CuO stretching and CuCl stretching and bending were identified. The implication from the study is that Raman spectroscopy can be a useful tool for identifying corrosion products of copper, brass and bronze objects of archaeological or antiquarian significance. In addition, the technique may be a useful aid in the restoration degraded pigment products from old paintings. Copyright © 2002 John Wiley & Sons, Ltd.