bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue factor activity in human monocytes is regulated by plasma: implications for the high and low responder phenomenon
Authors: Nijziel Marten , Van Oerle René , Van Cornelis , T Veer ‘ , Van Pampus Elisabeth , Lindhout Theo , Hamulyák Karly 
Published: July 2002

The ‘high and low responder phenomenon’ of monocyte tissue factor (MTF) activity has been attributed to effects on monocytes by granulocytes, platelets and lipopolysaccharide (LPS). To study the possible contribution of plasma to the high and low responder phenomenon, we measured the MTF activity in isolated cryopreserved human monocytes from two donors (monocytes A and monocytes B) after incubation in a plasma environment depleted of granulocytes, platelets and LPS. In buffer only, MTF activity was 643 and 679 fM (fM = final concentration of tissue factor), in normal pooled plasma, it was 1478 and 1615 fM (P = 0·001), respectively, in monocytes A and in monocytes B. Incubation with individual plasma samples from healthy controls (n = 43) gave a median MTF of 1355 fM (range 1044–1976 fM) and 1329 fM (range 858–1951 fM) respectively. A plasma consistently induced a higher or lower level of MTF activity in both monocytes: r = 0·82 (P < 0·00001). Coumarin use did not influence the high and low responder phenomenon. In the absence of granulocytes, platelets and LPS, plasma determines the high and low responder phenomenon. This phenomenon is not influenced by coumarin treatment.
Epidemiology of dementia in Nigeria: results from the Indianapolis–Ibadan study
Authors: Ogunniyi A. , Baiyewu O. , Gureje O. , Hall K. S. , Unverzagt F. , Siu S. H. , Gao S. , Farlow M. , Oluwole O. S. A. , Komolafe O. , Hendrie H. C. 
Published: July 2002

We determined the prevalence of dementia in a cohort of 2494 elderly Nigerians residents in Idikan Community, Ibadan, Nigeria. We utilized the Community Screening Instrument for Dementia to select subjects for clinical assessment in the second stage. The findings were compared with those of 2212 African Americans living in Indianapolis, studied simultaneously using similar methodology. The overall age‐adjusted prevalence rates of dementia and Alzheimer's disease in Ibadan were 2.29% and 1.41%, respectively. These rates were much lower than the respective values of 8.24% and 6.24% obtained for African Americans. In Ibadan, Alzheimer's disease accounted for 64.3% of the cases, with old age and female gender being the significant risk factors, whilst ‘living with others’ appeared to be protective (P < 0.05). Amongst African Americans, on the other hand, old age, rural living below the age of 19 years, low educational attainment and family history of dementia were the risk factors. There was a lack of association between Alzheimer's disease and possession of the apolipoprotein E ε4 allele in the Nigerian sample, unlike the finding in African Americans, where significant association was shown. In addition, the frequencies of the vascular risk factors investigated were lower in Nigerians.Our results showed lower prevalence of dementia and Alzheimer's disease in Nigerians, compared with African Americans. There was no association between Alzheimer's disease and apolipoprotein E (ε4 allele) in the former. The differences in the frequencies of vascular risk factors between Nigerian subjects and African Americans would suggest involvement of environmental factors in disease process.
Scratch resistance of rigid contact lens materials
Authors: Tranoudis Ioannis , Efron Nathan 
Published: July 2002

SummaryPractitioners have long recognised the importance of determining the extent of scratching on the surface of rigid contact lenses when deciding on lens replacement. Despite this, little research has been undertaken to define this problem. The extent of scratching of rigid contact lens materials was evaluated and this property was related to material oxygen permeability and refractive index. One hundred and forty lenses made from 28 different rigid materials were evaluated in a masked and randomised manner. Scratches were created on the front surface of the lenses using an apparatus that was specifically designed and constructed for this experiment. The extent of scratching was quantitatively evaluated using a computer‐based scanning and image analysis system. The oxygen permeability of all materials was measured using the polarographic method. An Atago N3000 hand‐held refractometer was used to measure the refractive index of these materials. Three significant correlations were revealed: an inverse relationship (r = −0.813, P < 0.0001) between oxygen permeability and refractive index; a positive relationship (r = 0.511, P < 0.008) between oxygen permeability and the extent of scratching; and an inverse relationship (r = −0.539, P < 0.0058) between refractive index and the extent of scratching. The information generated in this study concerning scratch resistance of rigid contact lens materials may assist the contact lens industry and contact lens practitioners in developing and prescribing rigid lenses with optimal performance characteristics.
Influence of viscosity variation on salt-finger instability in a fluid layer, a porous layer, and their superposition
Authors: Chen Falin , Lu Jay W. 
Published: July 2002

We consider the effect of temperature-dependent viscosity on the onset of buoyancy-driven salt-finger convection (stratifications of salt and temperature being destabilizing and stabilizing, respectively) in a horizontal fluid layer, a horizontal layer of a stratified porous medium, and in a horizontal fluid layer overlying a saturated porous medium. It is found that the viscosity variation affects the stability characteristics through two mechanisms. One is the formation of a relatively viscous sublayer which leads to multicellular convection and stabilizing; the other is the decrease of viscosity which favors the onset of convection. In a horizontal porous layer, the destabilizing mechanism prevails so that the motionless state becomes less stable as γ=ln(νmax/νmin), where ν is kinematic viscosity of the fluid, increases, and a general relation between critical solute (Rcsm) and thermal (Rm) Rayleigh numbers is found as Rcsm = Rm + 4π2H(γ), where H(γ) is determined by curve fitting on the basis of calculated results.
In a horizontal fluid layer, the first mechanism predominates the convection when γ&lt;6.86 and the second mechanism prevails when γ≳6.86; the motionless state is most stable at approximately γ=6.86. Another general relation between critical solute (Rcs) and thermal (R) Rayleigh numbers is also determined based on the calculated results as Rcs = R + 1070.76 G(γ). For superposed fluid and porous configuration, the stability characteristics become more complex and depend on the variations of γ,ζ (ratio of fluid layer depth to porous layer depth), and Rm, and so on. In general, the unicellular convection occurs for ζ=0.1 and the multicellular convection is observed for ζ≥ (R18)0.2; for Rm = 1, the stabilizing mechanism and destabilizing mechanism compete with each other; for Rm = 50, nevertheless, the stabilizing mechanism prevails so that increasing γ leads to stabilization; the fluid layer dominates the superposed system by convection at large γ for all ζ considered. The current results would provide valuable information for understanding the double-diffusive convection during the directional solidification of binary alloys.
Multiphoton ionization of SiH3 and SiD3 radicals: Electronic spectra, vibrational analyses of the ground and Rydberg states, and ionization potentials
Authors: Johnson Russell D. , Tsai Bilin P. , Hudgens Jeffrey W. 
Published: July 2002

The electronic spectra of silyl radicals, SiH3 and SiD3, were observed between 310 and 430 nm (46 000–64 000 cm−1) by resonance enhanced multiphoton ionization (REMPI) mass spectroscopy. The spectra were generated through a 2+1 REMPI mechanism. Two Rydberg series originating from planar, D3h point group states were observed. One series, of quantum defect δ=1.45(2), is comprised of the Ẽ 2A″2
(4p), J̃ 2A″2(5p), and M̃ 2A″2(6p) Rydberg states which have origins at ν0–0 =48 438, 56 929, and 60 341 cm−1 in SiH3 and at ν0–0 =48 391, 56 874, and 60 267 cm−1 in SiD3. In SiD3 the
P̃ 2A″2(7p) Rydberg origin was observed at ν0–0 =62 002 cm−1. The H̃, K̃, and Ñ states observed in the SiD3 spectrum comprise the second Rydberg series, δ=2.09, and were tentatively assigned as ns 2A′1 Rydberg states (n=5, 6, 7). The K̃ and Ñ origins were observed at ν0–0 =58 417 and 61 005 cm−1. A fit of the Rydberg formula to the np 2A″2(n≥5) origins found the adiabatic ionization potential of the SiH3 and SiD3 radicals to be IPa=8.135(+5,−2) eV and IPa=8.128(1) eV, respectively. Detailed vibrational analyses of these Rydberg states are presented. Analysis showed that in the Ẽ 2A″2 (4p) state of the SiH3 radical ω2 (a″2 symmetric bend)=796(7) and 2ω4 /2(e′ degenerate bend)=870(5) cm−1 and that in SiD3 radical ω′1 (a1 SiH3 symmetric stretch)=1576(3), ω′2 =589(3), and 2ω4 /2=635(6) cm−1. The REMPI spectra exhibited ν″2 hot bands from vibrational levels as high as Ev =2073 cm−1 in the X̃ 2A1state. Modeling calculations, which fit the numerous ν″2 hot bands, predicted barriers to inversion of Binv
=1935 cm−1 and Binv =1925 cm−1 for SiH3 and SiD3 X̃ 2A1 radicals, respectively.
Long-time quasilinear evolution of the free-electron laser instability for a relativistic electron beam propagating through a helical magnetic wiggler
Authors: Davidson Ronald C. , Yin Y. Z. 
Published: July 2002

The long-time quasilinear development of the free-electron laser instability is investigated for a tenuous electron beam propagating in the z direction through a helical wiggler field B0=−B̂ cos k0zêx−B̂ sin k0zêy. The analysis neglects longitudinal perturbations (δφ≂0) and is based on the nonlinear Vlasov–Maxwell equations for the class of beam distributions of the form fb(z,p,t) =n0δ(Px)δ(Py)G(z,pz,t), assuming ∂/∂x=0=∂/∂y. The long-time quasilinear evolution of the system is investigated within the context of a simple ‘‘water-bag’’ model in which the average distribution function G0( pz,t) =(2L)−1∫L−L dz G(z,pz,t) is assumed to have the rectangular form G0( pz,t) =[2Δ(t)]−1 for ‖pz−p0(t)‖ ≤Δ(t), and G0( pz,t) =0 for ‖pz−p0(t)‖ &gt;Δ(t). Making use of the quasilinear kinetic equations, a coupled system of nonlinear equations is derived which describes the self-consistent evolution of the mean electron momentum p0(t), the momentum spread Δ(t), the amplifying wave spectrum ‖Hk(t)‖2, and the complex oscillation frequency ωk(t) +iγk(t).
These coupled equations are solved numerically for a wide range of system parameters, assuming that the input power spectrum Pk(t=0) is flat and nonzero for a finite range of wavenumber k that overlaps with the region of k space where the initial growth rate satisfies γk(t=0) &gt;0. To summarize the qualitative features of the quasilinear evolution, as the wave spectrum amplifies it is found that there is a concomitant decrease in the mean electron energy γ0(t)mc2=[m2c4+e2B̂2/k20 +p20(t)c2]1/2, an increase in the momentum spread Δ(t), and a downshift of the growth rate γk(t) to lower k values. After sufficient time has elapsed, the growth rate γk has downshifted sufficiently far in k space so that the region where γk &gt;0 no longer overlaps the region where the initial power spectrum Pk(t=0) is nonzero. Therefore, the wave spectrum saturates, and γ0(t) and Δ(t) approach their asymptotic values.
Class analysis from a normative perspective*
Authors: Swift Adam 
Published: July 2002

ABSTRACTDistinguishing between an explanatory and a normative interest in social stratification, this paper considers the relation between class analysis and the value of equality. Starting from the familiar distinction between (in) equality of position and (in) equality of opportunity, and noting the extent to which mobility research focuses on the latter, it suggests that class positions can themselves be characterized in terms of the opportunities they yield to those occupying them. This enables the clear identification of the kinds of inequality that are and are not addressed by research findings presented in terms of class categories and odds ratios. The significance of those findings from a normative perspective is then discussed, and their limitations are emphasized – though the paper also explains in what ways they are indeed of normative relevance.
Towards the social analysis of twinship
Authors: Stewart Elizabeth A. 
Published: July 2002

ABSTRACTThe article examines the proposition that twinship is an irreducibly social phenomenon. Gender, age, birth order, socio‐economic status and other variables are considered, along with the role of different patterns of socialization as these affect twinship. It is argued that, to a very large extent, from conception, through gestation, childbirth and subsequently childhood and adolescence, the social processing and regulation of social members take place in unitary terms and that therefore twins (and higher multiples) are an anomaly in relation to such processes. Twins' reactions to stigma, stereotyping and labelling are explored as an integral aspect of the social structuring of twinship. The role of the twin, as distinct from the role of the non‐twin, is examined in the context of cultural expectations of twinship regarding similarity of identity and similarity of behaviour. Subsequent or concurrent processes of differentiation between twins are also examined. The article concludes with suggestions for further analyses of twinship.
Catalase and the production of brain acetaldehyde: a possible mediator of the psychopharmacological effects of ethanol
Authors: SMITH BRIAN R. , ARAGON CARLOS M. G. , AMIT ZALMAN 
Published: July 2002

AbstractThis review represents an attempt to assess the available data on the role of catalase in the mediation of the behavioral actions of ethanol and the regulation of voluntary ethanol consumption. It is argued that acetaldehyde may be formed in brain through the peroxidatic activity of catalase. Furthermore, acetaldehyde formed centrally through the activity of this enzyme, may be responsible, at least in part, for some of the motivational, behavioral and neurotoxic effects of ethanol.
A longitudinal group study of speech development in Danish children born with and without cleft lip and palate
Authors: Hutters Birgit , Bau Anja , Brøndsted Kirsten 
Published: July 2002

AbstractThe present study focuses on contoid vocalization by Danish 1‐year‐old unrepaired toddlers born with cleft lip and palate, and how they differ from their non‐cleft peers. Furthermore, we focus on how the same children master Danish consonants at 3 years of age compared with their non‐cleft peers in terms of their ability to produce consonants in accordance with adult target. Also, with the 3 year olds, we look at cleft speech characteristics as well as developmental speech characteristics found in both groups of children. Based on phonetic transcripion, it was found that Danish unoperated cleft palate children at 1 year of age produced few types of contoids and preferably contoids that did not require closure of the velopharyngeal port in their prespeech. In addition, the data suggest that consonants produced by cleft children who are treated with one‐stage surgery after speech onset, at 3 years of age differ from speech produced by non‐cleft children, not only as regards cleft speech characteristics, but also as regards developmental speech characteristics.
New practices for electronic publishing 2: New forms of the scientific paper
Authors: Kircz Joost G. 
Published: July 2002

ABSTRACTWe extend the analysis of our previous paper (Learned Publishing 2001: 265–72) to a broader discussion of the major features of electronic publications. We conclude that a distinctly different granularity of information will be required and that this will allow very different levels of authentication and quality control from those currently used for the traditional scientific paper.
Optimal spliced alignment of homologous cDNA to a genomic DNA
template
Authors: Usuka Jonathan , Zhu Wei , Brendel Volker 
Published: July 2002

Abstract
*To whom correspondence should be addressed.
Motivation: Supplementary cDNA or EST evidence is often decisive for discriminating between alternative gene predictions derived from computational sequence inspection by any of a number of requisite programs. Without additional experimental effort, this approach must rely on the occurrence of cognate ESTs for the gene under consideration in available, generally incomplete, EST collections for the given species. In some cases, particular exon assignments can be supported by sequence matching even if the cDNA or EST is produced from non-cognate genomic DNA, including different loci of a gene family or homologous loci from different species. However, marginally significant sequence matching alone can also be misleading. We sought to develop an algorithm that would simultaneously score for predicted intrinsic splice site strength and sequence matching between the genomic DNA template and a related cDNA or EST. In this case, weakly predicted splice sites may be chosen for the optimal scoring spliced alignment on the basis of surrounding sequence matching. Strongly predicted splice sites will enter the optimal spliced alignment even without strong sequence matching.
Results: We designed a novel algorithm that produces the optimal spliced alignment of a genomic DNA with a cDNA or EST based on scoring for both sequence matching and intrinsic splice site strength. By example, we demonstrate that this combined approach appears to improve gene prediction accuracy compared with current methods that rely only on either search by content and signal or on sequence similarity.
Availability: The algorithm is available as a C subroutine and is implemented in the SplicePredictor and GeneSeqer programs. The source code is available via anonymous ftp from ftp.zmdb.iastate.edu. Both programs are also implemented as a Web service at http://gremlin1.zool.iastate.edu/cgi-bin/sp.cgiand http://gremlin1.zool.iastate.edu/cgi-bin/gs.cgi, respectively.
Contact: vbrendel@iastate.edu
DaliLite workbench for protein structure comparison
Authors: Holm Liisa , Park Jong 
Published: July 2002

Abstract
Summary: DaliLite is a program for pairwise structure comparison and for structure database searching. It is a standalone version of the search engine of the popular Dali server. A web interface is provided to view the results, multiple alignments and 3D superimpositions of structures.
Availability: DaliLite has been ported to the Linux and Irix operating systems and can be compiled in many other UNIX operating systems. It is found at http://www.embl-ebi.ac.uk/dali/DaliLite.
Contact: holm@embl-ebi.ac.uk
A mixture model-based approach to the clustering of microarray
expression data
Authors: McLachlan G. J. , Bean R. W. , Peel D. 
Published: July 2002

Abstract
Motivation: This paper introduces the software EMMIX-GENE that has been developed for the specific purpose of a model-based approach to the clustering of microarray expression data, in particular, of tissue samples on a very large number of genes. The latter is a nonstandard problem in parametric cluster analysis because the dimension of the feature space (the number of genes) is typically much greater than the number of tissues. A feasible approach is provided by first selecting a subset of the genes relevant for the clustering of the tissue samples by fitting mixtures of tdistributions to rank the genes in order of increasing size of the likelihood ratio statistic for the test of one versus two components in the mixture model. The imposition of a threshold on the likelihood ratio statistic used in conjunction with a threshold on the size of a cluster allows the selection of a relevant set of genes. However, even this reduced set of genes will usually be too large for a normal mixture model to be fitted directly to the tissues, and so the use of mixtures of factor analyzers is exploited to reduce effectively the dimension of the feature space of genes.
Results: The usefulness of the EMMIX-GENE approach for the clustering of tissue samples is demonstrated on two well-known data sets on colon and leukaemia tissues. For both data sets, relevant subsets of the genes are able to be selected that reveal interesting clusterings of the tissues that are either consistent with the external classification of the tissues or with background and biological knowledge of these sets.
Availability: EMMIX-GENE is available at http://www.maths.uq.edu.au/~gjm/emmix-gene/
Contact: gjm@maths.uq.edu.au
Phenylalanine fluorescence studies of calcium binding to N‐domain fragments ofParameciumcalmodulin mutants show increased calcium affinity correlates with increased disorder
Authors: VanScyoc Wendy S. , Shea Madeline A. 
Published: July 2002

AbstractCalmodulin (CaM) is a ubiquitous, essential calcium‐binding protein that regulates diverse protein targets in response to physiological calcium fluctuations. Most high‐resolution structures of CaM‐target complexes indicate that the two homologous domains of CaM are equivalent partners in target recognition. However, mutations between calcium‐binding sites I and II in the N‐domain ofParameciumcalmodulin (PCaM) selectively affect calcium‐dependent sodium currents. To understand these domain‐specific effects, N‐domain fragments (PCaM1–75) of six of these mutants were examined to determine whether energetics of calcium binding to sites I and II or conformational properties had been perturbed. These PCaM(1–75)sequences naturally contain 5 Phe residues but no Tyr or Trp; calcium binding was monitored by observing the reduction in intrinsic phenylalanine fluorescence at 280 nm. To assess mutation‐induced conformational changes, thermal denaturation of the apo PCaM(1–75)sequences, and calcium‐dependent changes in Stokes radii were determined. The free energy of calcium binding to each mutant was within 1 kcal/mole of the value for wild type and calcium reduced the Rsof all of them. A striking trend was observed whereby mutants showing an increase in calcium affinity and Rshad a concomitant decrease in thermal stability (by as much as 18°C). Thus, mutations between the binding sites that increased disorder and reduced tertiary constraints in the apo state promoted calcium coordination. This finding underscores the complexity of the linkage between calcium binding and conformational change and the difficulty in predicting mutational effects.