bluuebunny/crossref_metadata_2025_split huggingface dataset:
OPTIMAL DESIGN OF ARTERIAL BYPASS PROSTHESES DIAMETER
Authors: STOYTCHEV S. , PALLOTTI G. , PETTAZZONI P. 
Published: July 2002

The objectives of this paper are: (1) to analyze how the bypass diameter and the degree of the stenosis affect the flow-induced wall shear stresses in the stenotic and bypass vessels and (2) to propose a clinically usable method for a proper selection of the bypass diameter. The problem is solved in the following stages: First, the steady pressure and flow within the vessels are obtained using general laws of mass and energy conservation. Then, on the basis of modified Womersley's theory to take into account the nonlinear mechanical properties of the vessels, the oscillating pressure and flow within the vessels are calculated. They are used to derive expressions for the reflection coefficients at the distal (converging) bifurcation and to calculate wall shear stresses. We hypothesize that the minimal differences in the wall shear stresses of the normal artery, stenotic artery and the bypass graft mitigate the development of anastomotic neointimal hyperplasia and graft pseudo intima. Using cost functions, based on steady and mean wall shear stresses, we calculated the optimal value of the undeformed bypass diameter for various degrees of stenosis. We found that the sum of cross-sectional areas of the optimal graft and the stenotic artery (normalized with respect to the cross-sectional area of the normal artery) varies between 1.14 and 1.28, an interval, which is consistent with the findings of McDonald (1974) for the area of the major branches in the body. Thus we conclude that the results obtained are consistent with the stated hypothesis.
Finite state verifiers II
Authors: Dwork Cynthia , Stockmeyer Larry 
Published: July 2002

The zero knowledge properties of interactive proof systems (IPSs) are studied in the case that the verifier is a 2-way probabilistic finite state automaton (2pfa). The following results are proved:
A new definition of zero knowledge is introduced. This definition captures a concept of “zero knowledge” for IPSs that are used for language recognition.
Bounding errors introduced by clustering of customers in closed product-form queuing networks
Authors: Cheng William C. , Muntz Richard R. 
Published: July 2002

Product-form queuing network models have been widely used to model systems with shared resources such as computer systems (both centralized and distributed), communication networks, and flexible manufacturing systems. Closed multichain product-form networks are inherently more difficult to analyze than open networks, due to the effect of normalization. Results in workload characterization for closed networks in the literature are often for networks having special structures and only specific performance measures have been considered.
In this article, we drive certain properties (insensitivity of conditional state probability distributions and fractional-linearity of Markov reward functions) for a broad class of closed multichain product-form networks. These properties are derived using the most basic flow balance conditions of product-form networks. Then we show how these basic properties can be applied in obtaining error bounds when similar customers are clustered together to speed up computation.
Detection of three-dimensional patterns of atoms in chemical structures
Authors: Lesk Arthur M. 
Published: July 2002

An algorithm for detecting occurrences of a three-dimensional pattern of objects within a larger structure is presented. The search technique presented uses the geometric structure of the pattern to define characteristics demanded of candidates for matching. This is useful in cases where the properties of each atom, considered individually, do not adequately limit the number of sets of possible matchings.
Several applications of this technique in the field of chemistry are: (1) in pharmacology: searching for a common constellation of atoms in molecules possessing similar biological activities; (2) in X-ray crystallography: fitting a structure or a structural fragment to a set of peaks in the electron-density distribution of a Fourier map; (3) in chemical documentation: retrieving from a file the structures containing specified substructures.
On the optimization of performance of time-sharing systems by simulation
Authors: Blatny J. , Clark S. R. , Rourke T. A. 
Published: July 2002

A simulation model of a time-sharing system with a finite noncontiguous store and an infinite auxiliary store is used to study the variation of system parameters such as store size, number of jobs allowed to execute simultaneously, job-scheduling algorithm, etc. The effects of these variations on a measure of system performance is used to ascertain which of the parameters controllable by the job-scheduling algorithm, including the scheduling itself, require optimization, and which of the parameters not normally controllable by the scheduling algorithm have a marked effect on system performance. System performance is based upon the mean cost of delay to all jobs processed.
It is shown that significant improvements in the measure of system performance can be obtained by using variable time-slice techniques and by selecting the optimum round-robin cycle time. It appears that these features would benefit from optimization whereas other parameters controllable by the scheduling algorithm affect system performance in a predictable manner and would not benefit from optimization.
Features not normally under the control of the scheduling algorithm can also have a marked effect on the measure of performance; in particular, supervisor overheads, the size of the store, and the speed of the CPU.
A comparison is made between the results of the simulation model and two analytical equations for quantum-oriented nonpreemptive time-sharing systems. The comparison is found to be very favorable.
A framework to support teaching in distributed systems
Authors: Burger C. , Rothermel K. 
Published: July 2002

Computer networks and distribute systems are characterized by highly dynamic, concurrent, and complex processes. Thus, training in this area requires great effort from both teachers and learners. Teachers are disatisfied with available methods for presentation, explanation, and exercises, and they are looking for better methods to support learners.
We have developed and architecture called Highly interactive simulation of algorithms and Protocols (HiSAP), consisting of a framework to build simulations and generate applets from formally specified algorithms or protocols. By modifying this specification and observing the resulting behavior, teaching and learning in a constructive manner is enabled. The framework is open to plug-in tools to show various aspects of HiSAP's behavior.
We present the results of some experiments with HiSAP at three different lectures for graduate students of distributed systems and computer networks.
CONFLICTING CONSTRUCTIONS OF DIVINE PRESENCE IN THE PRIESTLY TABERNACLE
Authors: Sommer Benjamin 
Published: July 2002

AbstractThe tabernacle described in the Pentateuch's P source yields two distinct and opposing interpretations. When compared with the tent found in the E collection of documents, P's tabernacle represents a classic example of what the historian of religions Jonathan Z. Smith terms a "locative" worldview. As an ideology of the center, this understanding of the priestly tabernacle asserts divine immanence and celebrates the sacrality of a particular space. When compared with the theology of the Jerusalem temple, however, P's tent seems to exemplify what Smith terms a "utopian" worldview, or what we might call a "locomotive" ideology. This construction of the tent eschews the notion of sacred center and emphasizes the periphery. Tension between texts exemplifying each of these two theoretical models is found throughout the Hebrew Bible (and throughout the history of religions), but in P, a single symbol encompasses both. The significance of this symbol depends on which of two different overlapping contexts (Torah and Tanakh) a reader privileges and which elements of its presentation in P one accentuates. Thus the priestly tabernacle works against itself, at once presenting and critiquing a theology of immanence. This ambivalent symbol suggests that God is present even as it intimates that God's presence in the world is inappropriate. Thus P is forerunner of postbiblical texts that describe God's exile in the created world.
RESPONSE TO THOMAS BERRY'S THE GREAT WORK
Authors: Cummings Neville Robert 
Published: July 2002

AbstractThis paper salutes four contributions of Berry's book: its return to creation rather than redemption as the central doctrine of Christianity, its expanded paideia beyond the male West, its focus on ecological problems as the agenda for all world religions, and its redefinition of the self in terms of orientations to nature and institutions. The paper then poses two questions. Why emphasize the Earth's ecology, with an emphasis of preservation and stability, rather than cosmic process which is entropic and a matter of trajectories? Why emphasize symmetry at the basis of the cosmos, with the emphasis on unity and order, rather than the asymmetry of unique creation with an emphasis on particularity and change?
SPELEONECTES EPILIMNIUS NEW SPECIES (REMIPEDIA, SPELEONECTIDAE) FROM SURFACE WATER OF AN ANCHIALINE CAVE ON SAN SALVADOR ISLAND, BAHAMAS
Authors: Yager Jill , Carpenter Jerry 
Published: July 2002

AbstractA new species of the crustacean class Remipedia, Speleonectes epilimnius, is described from the surface water of an anchialine cave on San Salvador Island in the southeastern Bahamas. It is the first remipede species to be collected at the surface of cave water rather than beneath a density interface. Principle characters include relatively long trunk segments and absence of swimming appendages on the last two trunk segments. Comparisons are made to the other 11 remipede species; a key to the genus is included. Se describe una nueva especie de crustaceo de la clase Remipedia, Speleonectes epilimnius, procedente de una cueva anquialina de la isla de San Salvador, sureste de las Bahamas. Esta es la primera especie que se ha observado en aguas superficiales, por encima de la interfase de densidad. Las principales caracteristicas de esta especie son los segmentos del tronco, relativamente largos, y la ausencia de apendices nadadores en los dos ultimos segmentos del tronco. Se compara esta especie con las restantes 11 especies de Remipedia. Se incluye una clave del g enero.
Hypo-osmotic regulation in entomopathogenic nematodes: Steinernema spp. and Heterorhabditis spp.
Authors: Piggott Simon , Perry Roland , Wright Denis 
Published: July 2002

Abstract
Entomopathogenic nematodes were incubated in a balanced salt solution based
on soil water analysis, supplemented with different concentrations of sodium
chloride. Two nematode isolates from Malaysia, Steinernema sp. SSL85
(isolate 25) and Heterorhabditis indicus (isolate 11), showed an initial
loss of water during the first 6 h of incubation in hyper-osmotic media (200
and 1000 mOsmKg-1) followed by a complete recovery of their water content
during the next 18-48 h. A third Malaysian isolate, Steinernema sp. (M1),
showed a more limited ability to regulate its water content. Studies on a
wild type H. megidis (UK 211) and one desiccation tolerant mutant indicate
that the ability for hypo-osmotic regulation does not necessarily involve
permeability differences in the cuticle. Régulation hypo-osmotique chez les
nématodes entomopathogènes: Steinernema spp. et Heterorhabditis spp. - Des
nématodes entomopathogènes ont été mis en incubation dans une solution
saline, équilibrée en fonction d'une analyse de l'eau contenue dans le sol,
et additionnée de chlorure de sodium en concentration variable. Deux isolats
de nématodes provenant de Malaisie, Steinernema sp. SSL 85 (isolat 25) et
Heterorhabditis indicus (isolat 11), ont montré une perte initiale d'eau au
cours des 6 premières heures d'incubation dans un milieu hyperosmotique (200
et 1000 mOsmKg-1), perte suivie par un rétablissement complet du contenu
hydrique au cours des 18 à 48 h suivantes. Un troisième isolat malaisien,
Steinernema sp. (M1) a montré une capacité plus limitée à réguler son
contenu hydrique. Des études ayant concerné un type sauvage d' H. megidis
(UK 211) et un mutant tolérant vis-à-vis de la dessication ont montré que la
capacité d'une régulation hypo-osmotique n'infère pas une différence dans la
perméabilité de la cuticule.
Heydenius brownii sp. n. (Nematoda: Mermithidae) parasitising a planthopper (Homoptera: Achilidae) in Baltic amber
Authors: Poinar George 
Published: July 2002

AbstractA fossil mermithid nematode, Heydenius brownii sp. n. (Nematoda: Mermithidae) emerging from a planthopper (Hemiptera: Fulgoroidea: Achilidae) in Baltic amber, is described. This is the first parasite of a fossil member of the order Hemiptera. There are no reports of mermithid parasitism of extant achilids; however, other families of planthoppers are attacked by mermithids in North America, Asia and Australia today. This find shows that parasitism of achilid fulgorids by mermithid nematodes was well established some 40 million years ago.
PARTNERS IN PASSAGE: THE EXPERIENCE OF MARRIAGE IN MID-LIFE
Authors: Appleton Cathy , Bohm Evelyn 
Published: July 2002

AbstractThe purpose of this phenomenological study is to describe the experience of enduring marriage in mid-life. The literature reveals a lack of research about contemporary mid-life marriage, reflecting only theoretical pieces and research studies on marital happiness, factors that make a marriage successful, and variables contributing to divorce. Noticeably absent are studies conducted from a phenomenological philosophical perspective. Questioning what enduring marriage involves for individuals in mid-life served to orient the researchers to the meaning of the experience. Seventeen volunteers participated in twenty-six initial and follow-up interviews. Using van Manen's methodological structure of human science research, a composite description that reflects enduring marriage in mid-life emerged. Two essential themes that characterize the experience, The Threads that Bind Us and A Season of Change and seven sub-themes explicating these essential themes portray the partnership of enduring mid-life marriage. The themes that comprise the structure of the experience reflect its form as a relational, time-space, and corporeal phenomenon. The findings are described in detail using narrative description in order to offer a rich account of each theme, and the implications provide a direction for future research.
Allophane-like materials in the weathered zones of Silurian phosphate-rich veins from Santa Creu d'Olorda (Barcelona, Spain)
Authors: Moro M. C. , Cembranos M. L. , Fernandez A. 
Published: July 2002

AbstractAllophane-like materials occur in the weathered zones of the phosphate-rich veins hosted in Silurian metasediments of the Catalonian Coastal Ranges. These metasediments also host sulphide and phosphate sedimentary mineralizations. Mineralogical and geochemical investigations of the allophanic samples indicate that they comprise Si-rich allophane, with a molar SiO2/Al2O3 ratio ranging between 1.19 and 2.23, with amorphous Al-(Ca) phosphate and hydroxylapatite as major minerals, and minor goethite and quartz. It is assumed that allophane, amorphous Al-(Ca) phosphate and hydroxylapatite come from the reaction of acid solutions, released during the weathering of sulphide interbedded in black shales, with phosphate-rich veins and volcano- sedimentary host rocks. Silica-alumina gels were deposited in fissures and cavities left by a previous dissolution of the phosphate-rich veins. Later the phosphate minerals filled the conchoidal microfractures and shrinkage microcracks of the allophane.
Correlation between reduciblity and composition of natural wolframite in Argentinian ore deposits
Authors: Botto I. L. , Barone V. L. , Sanchez M. A. , Schalamuk I. B. 
Published: July 2002

AbstractThermal reduction in wolframite (composition: Fe1-xMnxWO4 (0.08<x<0.87)) from different deposits in Argentina, was analysed using a temperature-programmed reduction (TPR) technique. X-ray powder diffraction analysis (XRPD), vibrational spectroscopy (IR and Raman), scanning electron microscopy (SEM) and electron microprobe analysis (EDAX) were used to assess the relationship between reactivity degree in a reducing atmosphere (H2 10% – N2 90%) and chemical composition of wolframite.Similar studies were carried out with other related minerals, especially the ones found in natural deposits as alteration or association products. Stability of the solid solution serial members is correlated with redox properties of divalent cations.
On the symmetry of tsumcorite group minerals based on the new species rappoldite and zincgartrellite
Authors: Effenberger H. , Krause W. , Bernhardt H.-J. , Martin M. 
Published: July 2002

AbstractRappoldite, the Co-analogue of helmutwinklerite, and zincgartrellite, the Zn-dominant analogue of gartrellite, are two new members of the tsumcorite group. Both minerals are triclinic, their structures are closely related to the parent structure, i.e. the ‘tsumcorite type’ (C2/m, Z = 2). The lower symmetry is caused by two different crystal-chemical requirements. Order phenomena of the hydrogen bonds cause the ‘helmutwinklerite type’ (P1̄, Z= 4), ordering of Cu2+and Fe3+ is responsible for the ‘gartrellite type’ (P1̄, Z = 1).Rappoldite was found on samples from the Rappold mine near Schneeberg, Saxony, Germany. The new species forms red to red-brown prismatic and tabular crystals up to 1 mm long. Dcalc. = 5.28 g/cm3. 2Vz = 85(5)°, nx = 1.85 (calc.), ny = 1.87(2) and nz = 1.90(2); dispersion is distinct with r > v; orientation is Y ∼∥ [1̄ 20] and X ∼ ∥ c. The empirical formula derived from electron microprobe analyses is (Pb1.01Ca0.01)Σ1.02(Co0.99Ni0.62Zn0.35Fe0.02)Σ1.98[(AsO4)1.99(SO4)0.01]Σ2.00[(OH)0.02(H2O)1.98]Σ2.00 or Pb(Co,Ni)2(AsO4)2·2H2O. Single-crystal X-ray studies showed average C2/m symmetry. Weak superstructure reflections are responsible for triclinic symmetry and enlarged cell metrics (refined from powder data): a= 11.190(2)Å, b= 10.548(2)Å, c= 7.593(1)Å, α = 100.38(1)8, β = 109.59(2)8, γ = 98.96(1)8, V= 807.6 Å3, Z= 4. The superstructure results from the hydrogen-bond scheme, but faint streaks indicate some disorder. All investigated rappoldite crystals are twinned by reflection on (23̄0) which corresponds to the mirror plane of the average C2/m cell. Helmutwinklerite is isotypic with rappoldite and probably also with pure thometzekite; sulphatian thometzekite is monoclinic.Zincgartrellite forms green-yellow rosette-like aggregates on samples from the Tsumeb mine, Namibia. The Dcalc. = 5.30 g/cm3. 2Vx = 87(5)°, nx = 1.91(2), ny = 1.94 (calc.) and nz = 1.97(2). Electron-microprobe analyses and Mössbauer data yielded the empirical formula (Pb0.97Ca0.04)Σ1.01(Zn0.91Cu0.51Fe0.59Al0.03)Σ2.04[(AsO4)1.96(SO4)0.01]Σ1.97[(OH)0.81(H2O)1.31]Σ2.12 or Pb(Zn,Fe,Cu)2(AsO4)2(H2O,OH)2. The structural formula is Pb(ZnxFe1–x)(ZnxCu1–x)(AsO4)2(OH)1–x(H2O)1+xwith 0.4 < x < 0.8. Gartrellite is defined by x < 0.4. Helmutwinklerite has x near to 1 and is defined by a cell with fourfold volume. Single-crystal X-ray studies of zincgartrellite proved space group P1̄ caused by ordering of Fe3+ and Cu at one atomic site. Cell parameters (refined from powder data): a= 5.550(1)Å, b= 5.620(1)Å, c= 7.621(1)Å, α = 68.59(1), β = 69.17(1), γ = 69.51(1)°, V= 200.1 Å3, Z= 1.
Eotaxin is a natural antagonist for CCR2 and an agonist for CCR5
Authors: Ogilvie Patricia , Bardi Giuseppe , Clark-Lewis Ian , Baggiolini Marco , Uguccioni Mariagrazia 
Published: July 2002

AbstractEotaxin is a potent inducer of eosinophil chemotaxis and was considered as a selective ligand of the CC chemokine receptor 3 (CCR3), which is expressed on eosinophils, basophils, and Th2 lymphocytes. This study shows that eotaxin also interacts with CCR2 and CCR5 and can, thus, affect the responses of monocytes, which express both receptors. In human monocytes pretreatment with eotaxin decreased responsiveness to MCP-1, a selective ligand for CCR2, as well as to RANTES and MIP-1β, which bind to CCR5. Similar effects were obtained with transfected cells expressing CCR2 or CCR5, but here a difference became apparent: Eotaxin triggered CCR5 at a concentration of 100 nM but not CCR2 even at 1 μM, suggesting an antagonistic effect on this receptor. In agreement with this observation, eotaxin induced internalization of CCR5 but not of CCR2 in human monocytes and transfected cells. Binding studies showed that eotaxin displaces125 I-MCP-1 from monocytes in a concentration-dependent manner, and functional experiments showed that eotaxin inhibits MCP-1-induced chemotaxis and enzyme release. The results demonstrate that eotaxin is a CCR5 agonist and a CCR2 antagonist. The present findings suggest a role of eotaxin in the fine-tuning of cellular responses occurring at sites of allergic inflammation, in which both MCP-1 and eotaxin are produced.
Molecular mechanism of transforming growth factor β–mediated cell-cycle modulation in primary human CD34+ progenitors
Authors: Dao Mo A. , Hwa Joseph , Nolta Jan A. 
Published: July 2002

AbstractThe mechanisms by which transforming growth factor β (TGF-β) exerts a negative effect on cell-cycle entry in primary human hematopoietic stem/progenitor cells were examined at the molecular and cellular levels. After treatment of primary human CD34+progenitors with TGF-β there was a decrease in the levels of cyclin D2 protein and an increase in levels of the cyclin-dependent kinase inhibitor (CDKI) p15 as compared to the levels in untreated cells. The converse was true after addition of neutralizing anti–TGF-β antibody. Administration of TGF-β to CD34+ cells in the presence of cytokines prevented retinoblastoma protein (pRb) phosphorylation, which occurred in the same cells treated with cytokines alone or cytokines and anti–TGF-β antibody. Neutralization of TGF-β during 24 to 48 hours of culture with cytokines significantly increased the number of colony-forming progenitors, but did not modulate the human stem cell pool, as measured in 6- to 12-month xenotransplantation assays. Equivalent numbers of human B, T, and myeloid cells were obtained after transplantation of cells treated with or without neutralization of TGF-β.