bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human B Cells Immortalized with Epstein-Barr Virus Upregulate CCR6 and CCR10 and Downregulate CXCR4 and CXCR5
Authors: Nakayama Takashi , Fujisawa Ryuichi , Izawa Dai , Hieshima Kunio , Takada Kenzo , Yoshie Osamu 
Published: July 2002

ABSTRACT
Compared to peripheral blood resting B cells, Epstein-Barr virus (EBV)-immortalized B cells consistently express CCR6 and CCR10 at high levels and CXCR4 and CXCR5 at low levels. Accordingly, these cells vigorously responded to the ligands of CCR6 and CCR10 but not to those of CXCR4 and CXCR5. In a human EBV-negative B-cell line, BJAB, stable expression of EBNA2 upregulated CCR6, while stable expression of EBNA2 as well as LMP1 downregulated CXCR4. On the other hand, upregulation of CCR10 or downregulation of CXCR5 was not induced in BJAB by stable expression of EBNA2 or LMP1. Thus, these changes may be due to a plasmablast-like stage of B-cell differentiation fixed by EBV immortalization. EBV-infected B cells in infectious mononucleosis are known to avoid germinal centers and accumulate under the mucosal surfaces. EBV-associated opportunistic lymphomas also tend to occur in extranodal sites. These preferred sites of in vivo localization are consistent with the unique profile of chemokine receptor expression exhibited by EBV-immortalized B cells.
The Crystal and Molecular Structure of a Zinc(II) Complex with a New Non-Symmetrical Tetradentate Schiff Base, [Zn(C15H18N3O)Br]
Authors: Ondráček Jan , Kratochvíl Bohumil , Haber Václav 
Published: July 2002

The structure of (1-(2-(2-aminoethylamino)ethylimino)methyl-2-napththolato-O,N,N',N")bromozinc(II), [Zn(naden)Br], containing a new Schiff base ligand, naden, was solved by Patterson and Fourier techniques and refined anisotropically to R = 0.047 for 1 426 unique observed reflections. The complex crystallizes in the space group Pbca with lattice parameters a = 14.024(1), b = 10.699(1), c = 21.635(2) Å, Z = 8. The structure of [Zn(C15H18N3O)Br] complex molecule consists of two six-membered aromatic rings and one six-membered and two five-membered chelate rings. The distorted coordinate polyhedron around Zn atom is formed by N1, N2, N3 and O atoms of the naden ligand and Br anion. Unusually short C-C bond in five-membered rings as well as small N-C-C-N torsion angles and somewhat large C4-C3-N2 and N2-C2-C1 angles are probably connected with intense thermal vibrations of C2 and C3 atoms. The structure is hold together by weak hydrogen bonds.
Pd-Cu Supported on Anionic Polymers - Promising Catalysts for Removal of Nitrates from Drinking Water
Authors: Gašparovičová Dana , Králik Milan , Hronec Milan 
Published: July 2002

Removal of nitrates from drinking water by catalytic hydrogenation over polymer supported Pd-Cu catalysts was studied. Precursors of the catalysts were prepared by ion exchange using microporous polymer cation-exchange resin Dowex 50 W X 4 in acid form and acetone-water solution of Pd and Cu acetates. The metals (approximately 2 and 0.5 wt.% of Pd and Cu, respectively) were reduced with NaBH4 in ethanol at room temperature or with H2 in MeOH at 50 °C and 1 MPa. Catalysts made it possible to reduce nitrate content in water from 100 mg/l to less than 50 mg/l after 4 h of batch treatment with hydrogen-nitrogen mixture (43 vol.% H2) at ambient temperature and atmospheric pressure under vigorous stirring of the reaction mixture. The importance of acid sites of the catalyst for the selective hydrogenation of nitrates to nitrogen was demonstrated by a higher overall selectivity (about 60 mole %) obtained on catalysts containing acid sites than on catalysts without acid sites (about 20 mole %). Catalysts bearing acid sites are promising candidates for removal of nitrates, formed ammonia, as well as other cations because of parallel acting as catalysts and cation exchangers. The used catalysts were regenerated with a low concentrated mineral acid.
Perception of changes in wall tension of the proximal stomach in humans
Authors: Piessevaux H , Tack J , Wilmer A , Coulie B , Geubel A , Janssens J 
Published: July 2002

BACKGROUNDHypersensitivity to distension of the stomach is a frequent finding in functional dyspepsia. During gastric distension studies both wall tension and elongation are increased.AIMWe wished to distinguish changes in wall tension from changes in elongation in the genesis of perception of mechanical stimuli originating from the proximal stomach in healthy subjects.SUBJECTS AND METHODSTwenty six volunteers were studied using gastric barostat and antroduodenal manometry. In 14 subjects, stepwise isobaric and isovolumetric distensions were performed before and during erythromycin infusion. In all volunteers, on a separate occasion, phasic contractions of the proximal stomach were detected as intraballoon pressure increases during fixed volume inflation. These contractions were matched with perception changes during two 10 minute periods, before and during administration of erythromycin.RESULTSErythromycin significantly lowered the perception and discomfort thresholds during stepwise gastric distension. During fixed volume inflation, erythromycin increased the number and amplitude of fundic contractions and enhanced their perception from 51.1 (7.4)% to 64.0 (4.7)%. The proportion of perception score increases coinciding with fundic contractions increased from 47.3 (0.7)% to 81.5 (0.5)%. The amplitude of correctly identified isolated fundic pressure waves was higher compared with non-identified waves.CONCLUSIONSThese results support the hypothesis that changes in gastric wall tension may be involved in the genesis of symptoms originating from the stomach.
Properties of ER Fluids Comprised of Liquid Crystalline Polymers
Authors: Inoue Akio , Ide Yoichiroh , Maniwa Shyunji , Yamada Hiroyuki , Oda Hiroji 
Published: July 2002

Side-chain liquid crystalline polysiloxanes (LCS) diluted with solvents show a large increase in viscosity and a newtonian flow under an electric field. Two types of solvent-diluted LCSs, A and B, are presented and their properties are described in this paper. Type A shows a large temperature-dependent ER effect a quick response of msec. order to an electric field and a dynamic behavior similar to that of a low molecular weight liquid crystal. Type B shows a stable ER effect throughout a wide range of temperatures up to 150°C, a two-step response of shear stress curve upon application of DC electric field and a micron-sized droplets structure which deforms with the electric field. The generation mechanisms of ER effect on the two types were discussed with the data of dynamic and morphological changes, referring those on a low molecular liquid crystal and a particle dispersion type ER fluid.
UNIFORMITIES ON FREE SEMIGROUPS
Authors: PIN J.-E. , WEIL P. 
Published: July 2002

It is known that the profinite completions of a free semigroup which are associated with a pseudovariety of semigroups or of ordered semigroups, can be defined by an écart or a quasi-écart. We characterize those quasi-écarts and those quasi-uniformities which arise in this fashion. We also prove an Eilenberg-like one-to-one correspondence between pseudovarieties of ordered semigroups and so-called varieties of quasi-uniformities. Résumé: On sait que les complétions profinies d'un semigroupe libre qui sont associées à une pseudovariété de semigroupes ou de semigroupes ordonnés peuvent être définies par un écart ou un quasi-écart. Nous caractérisons les quasi-écarts et les quasi-uniformités qui peuvent étre obtenues de cette façon. Nous démontrons également l'existence d'une correspondance injective "à la Eilenberg", entre pseudovariétés de semigroupes ordonnés et ce que nous appelons des variétés de quasi-uniformités.
UNDECIDABILITY, AUTOMATA, AND PSEUDOVARITIES OF FINITE SEMIGROUPS
Authors: RHODES JOHN 
Published: July 2002

The author proves for each of the operations # equalling *, °, **, □ or m, there exist pseudovarieties of finite semigroups [Formula: see text] and [Formula: see text] with decidable membership problems, such that [Formula: see text] has an undecidable membership problem. In addition, if [Formula: see text] denotes the pseudovariety of all finite aperiodic semigroups, [Formula: see text] denotes the pseudovariety of all finite groups, and [Formula: see text](E) denotes the pseudovariety of all finite aperiodic semigroups satisfying the finite number of equations E, then it is proved that there exists E such that [Formula: see text](E) has an undecidable membership problem. Note [Formula: see text] equals all semigroups of complexity ≤1. Section 6 is expanded into a joint paper with B. Steinberg, following this paper.
Ge/Ag(111): SURFACE ALLOY OF A SEMICONDUCTOR ON A METAL
Authors: OUGHADDOU H. , AUFRAY B. , GAY J. M. 
Published: July 2002

We present one of the first experimental studies of the formation of an ordered surface alloy of a semiconductor, Ge, and a metal, Ag, with bulk tendency to phase separation. The kinetics of growth at room temperature as well as the surface segregation of Ge have been investigated for the (111) orientation using Auger Electron Spectroscopy (AES) and Low Electron Energy Diffraction (LEED). The growth mode of Ge on Ag(111) is layer-by-layer like up to at least two layers. An unexpected ordered surface alloy forming a [Formula: see text] superstructure is observed during the growth at 1/3 germanium monolayer, followed by a p(7× 7) superstructure at one-monolayer coverage. The surface Ge segregation studied via both dissolution and segregation kinetics shows the particular stability of the ordered [Formula: see text] surface alloy.
EVALUATION OF RECONSTRUCTIONS OF THE UNSTABLE DISTAL ULNA
Authors: Tsuruta Toshiyuki , Rosales Roberto S. , Scheker Luis R. 
Published: July 2002

Because the distal radioulnar joint (DRUJ) is a weight-bearing joint, surgical procedures treating DRUJ instability must be evaluated accordingly. Biomechanically, such procedures can be viewed from two approaches: One that preserves DRUJ biomechanics, which includes Groups A (intracapsular anatomical reconstruction) and B (ulnar shortening alone); and another that radically alters DRUJ biomechanics, which includes Groups C (tendon sling) and D (resection of ulnar head). This study compared the results of these two approaches. Sixty-four patients having DRUJ surgery between 1984 and 1993 met the inclusion criteria of painful dorsal dynamic DRUJ instability, no DRUJ arthrosis, and no ulnocarpal impingement. However, only 25 returned for follow-up examination (Group A, 14 patients; B, 3; C, 2; D, 6). Grip strength, instability, pain, ROM, and satisfaction were scored. The total scores of Groups A and B combined were significantly better than those of Groups C and D combined. Scores for pain with lifting weight and for instability in the combined Groups A and B were significantly better than those in the combined Groups C and D. Although the number of patients who returned for follow-up was small, the significantly better scores achieved by the groups whose procedures preserved DRUJ biomechanics (anatomical reconstruction or ulnar shortening), indicate that these procedures may be the treatment of choice over the techniques that radically alter the DRUJ biomechanics (tendon slings or ulnar head resection).
Vertical partitioning algorithms for database design
Authors: Navathe Shamkant , Ceri Stefano , Wiederhold Gio , Dou Jinglie 
Published: July 2002

This paper addresses the vertical partitioning of a set of logical records or a relation into fragments. The rationale behind vertical partitioning is to produce fragments, groups of attribute columns, that “closely match” the requirements of transactions.
Vertical partitioning is applied in three contexts: a database stored on devices of a single type, a database stored in different memory levels, and a distributed database. In a two-level memory hierarchy, most transactions should be processed using the fragments in primary memory. In distributed databases, fragment allocation should maximize the amount of local transaction processing.
Fragments may be nonoverlapping or overlapping. A two-phase approach for the determination of fragments is proposed; in the first phase, the design is driven by empirical objective functions which do not require specific cost information. The second phase performs cost optimization by incorporating the knowledge of a specific application environment. The algorithms presented in this paper have been implemented, and examples of their actual use are shown.
Efficient equivalence checking of multi-phase designs using phase abstraction and retiming
Authors: Hasteer G. , Mathur A. , Bannerjee P. 
Published: July 2002

Equivalence checking of finite state machines (FSMs) traditionally assumes single phase machines where a single clock (implicit or explicit) synchronizes the state of the FSM. We extend the equivalence checking paradignm to FSMs with multi-phase clocks. Such designs are becoming increasingly popular in high performance microprocessors since they result in lower synchronization overhead. In addition, aggressive pipelining and the use of “sparse” encodings results in designs where the ratio of steady states to the total state space is very low. In this paper, we show that automatically transforming such designs to ones that have more “dense” encodings can result in significant benefits in using implicit BDD-based techniques for their verification. We explore two such techniques:
phase abstraction
and
retiming
and demonstrate their utility in the context of FSM equivalence checking. The main contributions of our work are:

—We show that a multi-phase FSM can be transformed to a functionally equivalent one phase FSM and this phase abstraction leads to significant improvement in the size of FSMs that can be checked for equivalence.
—We show that min-latch retiming preserves equivalence and can be performed efficiently in multi-phase designs, even when latch borrowing and discarding is allowed at the primary inputs and outputs.
—We demonstrate the utility of our approach on several controller FSMs from the industry.
Evaluation of step directions in optimization algorithms
Authors: Davidon William C. , Nocedal Jorge 
Published: July 2002

We present a method for comparing that part of optimization algorithms that chooses each step direction. It is an example of a general approach to algorithm evaluation in which one tests specific parts of the algorithm, rather than making overall evaluations on a set of standard test problems. Our testing procedure can he useful for developing new algorithms and for writing and evaluating optimization software.
We use the method to compare two versions of the conjugate gradient algorithm, and to compare these with an algorithm based on conic functions.
Mathematical models of database degradation
Authors: Heyman Daniel P. 
Published: July 2002

As data are updated, the initial physical structure of a database is changed and retrieval of specific pieces of data becomes more time consuming. This phenomenon is called database degradation. In this paper two models of database degradation are described. Each model refers to a different aspect of the problem.
It is assumed that transactions are statistically independent and either add, delete, or update data. The first model examines the time during which a block of data is filling up. The second model examines the overflows from a block of data, which essentially describes the buildup of disorganization. Analytical results are obtained for both models. In addition, several numerical examples are presented which show that the mean number of overflows grows approximately linearly with time. This approximation is used to devise a simple formula for the optimal time to reorganize a stochastically growing database.
Note on the Practical Computation of Proper Values
Authors: Fike C. T. 
Published: July 2002

It has been suggested by Householder [1] and by Householder and Bauer [2] that orthogonal similarity transformations of matrices are particularly stable with respect to the practical computation of proper values. It is the purpose of this note to examine this question and to demonstrate in terms of a “condition number” to be defined below a sense in which this conjecture is true.
Broadly speaking, any problem may be termed “ill-conditioned” for which the solution is acutely sensitive to slight variations in the parameters of the problem. Examples of ill-conditioning occur in many contexts. Computers are familiar with the phenomenon as it manifests itself, for example, in the study of matrix inversion. Since our purpose is to study the conditioning of matrices specifically for the proper value problem, it is convenient to have a nomenclature and notation which will avoid confusion with conditioning as it is used in other senses.
An Automatic Sequencing Procedure with Application to Parallel Programming
Authors: Schwartz Eugene S. 
Published: July 2002

An automatic sequencing procedure for assigning sets of instructions to predesignated autonomous units of a multiprocessor is described. The procedure is based upon an assignment matrix developed from a precedence matrix. By associating a column vector whose elements are the operation time of each instruction set with the assignment matrix, numerical computation is made possible. A topological index, the precedence number, stating the position of each instruction set in relation to the last set in its path is contained in a second column vector. A transfer matrix in conjunction with an automatically derived path table is employed in a multipath program.
Six generalized rules are derived for the procedure which proceeds directly to a solution without obtaining and testing all permutations of the sets of instructions, and seeks to establish a sequence of operations to minimize the total operation time while satisfying all precedence restrictions. Since the procedure does not require looking at the last instruction set before releasing the first sets for assignment to units, computer processing may start after the first assignment period is completed with processing and subsequent sequencing taking place concurrently.
The procedure is readily adaptable to computer operation and automatic development of the assignment matrix is described. A flow chart of the procedure and its use for solution of a problem is presented. The solution obtained is guaranteed to be feasible although it is not necessarily unique. In the examples tested, an optimum or near optimum solution has been obtained. Computational experience with the procedure in complex problems is required to determine its effectiveness in such cases.
Music and computer composition
Authors: Moorer James Anderson 
Published: July 2002

The problem discussed is that of simulating human composition of Western popular music by computer and some relevant theories of music and harmony are given. Problems with this kind of program and several schemes that are known not to work are discussed. Several previous computer compositions are discussed, including the ILLIAC Suite.
A program to generate short melody fragments was written to simulate some of the aspects of human composition. Five samples of its output are presented and discussed. It was discovered that although the fragments show many of the characteristics of popular melodies, they have a strangely alien sound. It is theorized that this is because the relevant probabilities which would discriminate against unfamiliar sequences were not used.
The Role of Perceptual Load in Neglect: Rejection of Ipsilesional Distractors is Facilitated with Higher Central Load
Authors: Lavie Nilli , Robertson Ian H. 
Published: July 2002

Abstract
Neglect is known to produce a bias towards the ipsilesional side. Here we examined whether this bias is automatic or can be modulated by manipulating perceptual load in a relevant task [e.g., Lavie, N. (1995). Perceptual load as a necessary condition for selective attention. Journal of Experimental Psychology: Human Perception and Performance, 21, 451–468]. Three patients with left neglect and three healthy controls made speeded choice responses to a target letter in the center of the display while attempting to ignore an irrelevant distractor presented on left or right. Perceptual load was manipulated by inducing a search for the target that appeared with another central stimulus, which was either a blob (low load) or a nontarget letter (higher load). Response competition effects from ipsilesional distractors were significantly reduced by higher load. The same increase of load, however, did not decrease distractor effects in the control group, as expected [e.g., Lavie, N., & Cox, S. (1997). On the efficiency of attentional selection: Efficient visual search results in inefficient rejection of distraction. Psychological Science, 8, 395-398]. These results demonstrate that ipsilesional bias in neglect is not fully automated and emphasize an additional restriction of perceptual capacity. Moreover, they supported our prediction that reduced perceptual capacity in neglect can lead to improved distractor rejection with just small increases in perceptual load.
Residual Vision in a Subject with Damaged Visual Cortex
Authors: Schärli Heinz , Harman Alison M. , Hogben John H. 
Published: July 2002

Abstract
It is well known that a lesion in the optic radiation or striate cortex leads to blind visual regions in the retinotopically corresponding portion of the visual field. However, various studies show that some subjects still perceive certain stimuli even when presented in the “blind” visual field. Such subjects either perceive stimuli abnormally or only certain aspects of them (residual vision) or, in some cases, deny perception altogether even though visual performance can be shown to be above chance (blindsight). Research on monkeys has suggested a variety of parallel extrastriate visual pathways that could bypass the striate cortex and mediate residual vision or blindsight. In the present study, we investigated a subject with perimetrically blind visual areas caused by bilateral brain damage. Black and white stimuli were presented at many locations in the intact and affected areas of the visual field. The subject's task was to state, using confidence levels, whether the target stimulus was black or white. The results revealed an area in the “blind” visual field in which the subject perceived a light flash when the experimental black stimulus was presented. We hypothesize that a spared region in the visual cortex most likely accounts for these findings.
Oxygen and the Trade-off between Egg Ventilation and Brood Protection in the Common Goby
Authors: Jones Jackie , Reynolds John 
Published: July 2002

Abstract1. We examined compromises between defence of nests against predation and ventilation of eggs in the common goby (Pomatoschistus microps). Females are known to prefer nests with small entrances, which are less vulnerable to predatory shore crabs, Carcinus maenus. However, small nest entrances may hamper egg ventilation by males. This may be especially detrimental under conditions of low dissolved oxygen. 2. Males did not make smaller entrances to their nests when in the presence of predatory crabs, but they had larger entrances under low oxygen than in normal oxygen levels. 3. Males diverted time from ventilating nests to attacking crabs. 4. Thus, males exchanged direct care of the eggs for protection against predators by reducing their fanning activity, but not according to needs of their eggs for oxygenation. This trade-off may therefore impose a greater cost to egg survival for males in low oxygen.