bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel Bvar allele (547 G>A) demonstrates differential expression depending on the co‐inherited ABO allele
Authors: Cho D. , Kim S. H. , Ki C. S. , Choi K. L. , Cho Y. G. , Song J. W. , Shin J. H. , Suh S. P. , Yazer M. H. , Ryang D. W.
Published: November 2004

Background and Objectives  Genetic analysis of group B donors in Korea was performed.

Materials and Methods  Exons 6 and 7 were sequenced in 12 phenotypically B3 donors 6 B3, 6 A1B3.

Results  Consensus sequences all B3 and 2/6 A1B3 donors were present. Four A1B3 donors demonstrated a novel B allele, Bvar, in the context of A101/ or A102/Bvar genotypes. Family studies based on an A1B3 donor with the Bvar allele and on another unrelated subject with identical genotype and phenotype revealed Bvar/O01 genotypes with full B‐antigen expression.

Conclusions  B

var
allele is subject to differential expression, depending on the co‐inherited ABO allele.
ENZYMATIC BIOREMEDIATION: FROM ENZYME DISCOVERY TO APPLICATIONS
Authors: Sutherland TD , Horne I , Weir KM , Coppin CW , Williams MR , Selleck M , Russell RJ , Oakeshott JG
Published: November 2004

1. Enzymatic bioremediation is potentially a rapid method of removing environmental pesticide residues. Applications include the treatment of residues resulting from agricultural production and processing industries, such as the treatment of irrigation waters, surface‐contaminated fruit and vegetables and spent dip liquors.

2. A specific application for some organophosphate‐degrading enzymes involves detoxification of nerve agent stockpiles. Effective and affordable remediation requires highly specialized enzymes, so protein engineering techniques are being used to improve properties of various source enzymes to enhance catalytic rates, stability and substrate range.

3. Trials with an optimized organophosphate‐degrading enzyme have shown the feasibility of such technology in various applications.

4. The enzymes developed for environmental remediation for specific pesticide classes also have applications as antidotes for high‐dose pesticide poisonings and as prophylaxis for people at risk of high pesticide doses.
THE JANUS* FACES OF ADRENOCEPTORS: FACTORS CONTROLLING THE COUPLING OF ADRENOCEPTORS TO MULTIPLE SIGNAL TRANSDUCTION PATHWAYS
Authors: Summers Roger J , Broxton Natalie , Hutchinson Dana S , Evans Bronwyn A
Published: November 2004

1. The adrenoceptors (AR) are an important subfamily of rhodopsin‐like G‐protein‐coupled receptors that couple to an increasingly large number of signalling mechanisms. Two important factors that determine the pathways that are used are the C‐terminal region of the receptor and the agonist used to activate the receptor.

2. Studies of splice variants of the mouse β3‐AR showed that the C‐terminus is a factor controlling the signalling characteristics. Although these receptors differ only at the C‐terminus, the β3b‐AR coupled to both Gs and Gi, whereas the β3a‐AR coupled solely to Gs.

3. Examination of four splice variants of the human α1A‐AR showed that all were able to couple to pertussis toxin‐sensitive G‐proteins, even though they have radically different C‐terminal regions.

4. Comparison of the effects of the β3‐AR ligands CL316243 and SR59230A showed that both can activate the mouse β3‐AR but that SR59230A uses pathways other than cAMP accumulation in 3T3‐F442A cells.

5. Examination of a series of α1‐AR agonists for their ability to activate a number of signalling pathways revealed that A61603 acted as a full agonist in all assays, whereas oxymetazoline was unable to cause cAMP accumulation, suggesting agonist‐selective signalling at the human α1A‐AR.
We Ran One Regression*
Authors: Hendry David F. , Krolzig Hans‐Martin
Published: November 2004

The controversy over the selection of ‘growth regressions’ was precipitated by some remarkably numerous ‘estimation’ strategies, including two million regressions by Sala‐i‐Martin [American Economic Review(1997b) Vol. 87, pp. 178–183]. Only one regression is really needed, namely the general unrestricted model, appropriately reduced to a parsimonious encompassing, congruent representation. We corroborate the findings of Hoover and Perez [Oxford Bulletin of Economics and Statistics(2004) Vol. 66], who also adopt an automatic general‐to‐simple approach, despite the complications of data imputation. Such an outcome was also achieved in just one run ofPcGets, within a few minutes of receiving the data set in Fernández, Ley and Steel [Journal of Applied Econometrics(2001) Vol. 16, pp. 563–576] from Professor Ley.
A Protein's Final ESCRT
Authors: Babst Markus
Published: November 2004

In eukaryotic cells, delivery of transmembrane proteins into the lumen of the lysosome for degradation is mediated by the multivesicular body pathway. The function of the ESCRT protein complexes is required for both the formation of multivesicular body lumenal vesicles and the sorting of endosomal cargo proteins into these vesicles. Recent studies have identified additional factors that seem to function as an upstream cargo retention system feeding into the ESCRT machinery, given new insights into the dynamic structure of multivesicular bodies, and identified a potential mechanism for multivesicular body vesicle formation.
Cardiac MRI for the Assessment of Myocardial Viability
Authors: Sandstede J. J. W.
Published: November 2004

Diagnosis of myocardial viability after infarction focuses on the prediction of functional improvement of dysfunctional myocardium after revascularization therapy. Magnetic resonance imaging (MRI) provides morphological and functional approaches for the assessment of myocardial viability. The morphological approach is based on the detection of the ratio viable/non‐viable cells. The end‐diastolic wall thickness is an indirect parameter of this ratio, because thinned myocardium contains a reduced number of viable cells. This approach is easy to perform and has a high sensitivity, but a low specificity and can only be used 4 months after myocardial infarction due to infarct healing processes. Delayed enhancement allows for direct visualization of necrotic or scarred tissue. By measuring the transmural extent of delayed enhancement, the probability of mechanical improvement can precisely be given. Imaging of microvascular obstruction by first‐pass perfusion or delayed enhancement gives additional information on viability and patient prognosis. Low‐dose dobutamine‐stress as the functional approach has a good sensitivity with a high specificity for the prediction of wall motion improvement and may provide additional information in patients with transmural extent of delayed enhancement between 1 and 75%. In conclusion, cardiac MRI offers several clinically usable approaches for the assessment of myocardial viability and is about to become the method of choice in the near future.
Proteoglycans and injury of the central nervous system
Authors: Matsui Fumiko , Oohira Atsuhiko
Published: November 2004

ABSTRACT  Proteoglycan is a family of glycoproteins which carry covalently‐linked glycosaminoglycan chains, such as chondroitin sulfate and heparan sulfate. Proteoglycans are believed to play important roles in morphogenesis and maintenance of various tissues including the central nervous system (CNS) through interactions with cell adhesion molecules and growth factors. In the CNS, a significant amount of evidence has been accumulated to show that proteoglycans function as modulators in various cellular events not only in the development, but also in the pathogenesis of neuronal diseases and lesions. When the CNS is injured, several chondroitin sulfate proteoglycans (CSPG) are up‐regulated in glial scars formed around the lesion site. The glial scar also contains some molecules inhibitory to axonal growth, such as myelin‐associated glycoprotein, Nogo, and Semaphorin. In vitro studies revealed that CSPG largely exert a repulsive effect on axonal regeneration, and a signal from CSPG modulates the actin cytoskeleton of outgrowing neurites through the Rho/ROCK pathway. These findings suggest that CSPG are responsible for unsuccessful axonal regeneration in glial scars. Various attempts to overcome the inhibitory effect of CSPG have been pursued in vivo. Digestion of chondroitin sulfate chains by chondroitinase ABC, suppression of CSPG core protein synthesis by decorin, suppression of glycosaminoglycan chain synthesis by a DNA enzyme, and inhibition of the Rho/ROCK pathway with specific inhibitors were all successful for increasing axonal regeneration. For a clinical application, the most effective combination of these treatments needs to be examined in the future.
Genetically decreasedCYP2A6and the risk of tobacco dependence: a prospective study of novice smokers
Authors: O’Loughlin J , Paradis G , Kim W , DiFranza J , Meshefedjian G , McMillan-Davey E , Wong S , Hanley J , Tyndale R F
Published: November 2004

Objective:Case control studies in adults suggest that defective alleles in the gene that codes for the hepatic cytochrome P450 2A6 (CYP2A6) protect against nicotine dependence (ND) and higher levels of cigarette consumption. These two hypotheses were tested in young adolescents.

Design:Self reports of tobacco use and ND symptoms were collected every 3–4 months in a prospective study of 1293 grade 7 students from a convenience sample of 10 schools.

Subjects:281 smokers with genetic data were analysed; those who were not already tobacco dependent and who had inhaled (n  =  228) were followed 29.9 months on average, until they became dependent or were censored.

Main outcome measures:The association between metabolic activity, represented byCYP2A6genotype, and conversion to dependence was analysed using Cox’s proportional hazards model.

Results:During follow up 67 subjects (29.4%) became dependent. Relative toCYP2A6*1/*1, having 1–2 copies of the inactiveCYP2A6*2or*4variant was a strong risk factor for developing dependence (hazard ratio 2.8, 95% confidence 1.3 to 6.3). Subjects with 1–2 partially inactiveCYP2A6*9or*12variants were not at increased risk. Mean past-week cigarette consumption at the end of follow up (controlling for age, sex, and number of months since first inhalation) among dependent subjects was 29.1 among normal inactivators, compared to 17.2, and 12.7 among slower (1–2 copies of *9or *12), and slowest (1–2 copies of*2or*4) inactivators, respectively (p  =  0.09).

Conclusion:Adolescents with 1–2 copies ofCYP2A6*2or *4are at substantially increased risk of becoming dependent but smoke less once dependent. Genetic risk for ND may need to be considered in the conceptualisation of tobacco control programmes for adolescents.
Industry sponsored youth smoking prevention programme in Malaysia: a case study in duplicity
Authors: Assunta M , Chapman S
Published: November 2004

Objective:To review tobacco company strategies of using youth smoking prevention programmes to counteract the Malaysian government’s tobacco control legislation and efforts in conducting research on youth to market to them.

Methods:Systematic keyword and opportunistic website searches of formerly private internal industry documents. Search terms included Malay, cmtm, jaycees, YAS, and direct marketing; 195 relevant documents were identified for this paper.

Results:Industry internal documents reveal that youth anti-smoking programmes were launched to offset the government’s tobacco control legislation. The programme was seen as a strategy to lobby key politicians and bureaucrats for support in preventing the passage of legislation. However, the industry continued to conduct research on youth, targeted them in marketing, and considered the teenage market vital for its survival. Promotional activities targeting youth were also carried out such as sports, notably football and motor racing, and entertainment events and cash prizes. Small, affordable packs of cigarettes were crucial to reach new smokers.

Conclusion:The tobacco industry in Malaysia engaged in duplicitous conduct in regard to youth. By buying into the youth smoking issue it sought to move higher on the moral playing field and strengthen its relationship with government, while at the same time continuing to market to youth. There is no evidence that industry youth smoking prevention programmes were effective in reducing smoking; however, they were effective in diluting the government’s tobacco control legislation.
UNIFORM ALGEBRAIC SPECIFICATIONS OF FINITE SETS WITH EQUALITY
Authors: BERGSTRA J.A. , MAUW S. , WIEDIJK F.
Published: November 2004

We study a variety of ways to specify a two sorted structure involving the Booleans B, with constants true and false and a finite set D with an equality function eq to the Booleans, under the assumption that there is a constant (name) for each element of D. The specifications are evaluated with respect to several properties, like textual length, efficiency in execution and the use of special features.
SYSTOLIC TREE WITH BASE AUTOMATA
Authors: MONTI A. , PARENTE D.
Published: November 2004

Different systolic tree automata (STA) with base (T(b)−STA) are compared. This is a subclass of STA with interesting properties of modularity. We give a necessary and sufficient condition for the inclusion between classes of languages accepted by T(b)− STA, (L(T(b)−STA)), as b varies. We focus on T(b)−STA obtained by varying the base b in a natural way. We prove that for every base b within this framework there exists an a such that L(T(a)−STA) is not contained in L(T(b)−STA). We characterize the family of languages accepted by T(b)−STA when the input conditions are relaxed. Moreover we show that the emptiness problem is decidable for T(b)−STA.
ON THE LIMITATIONS OF LOCALLY ROBUST POSITIVE REDUCTIONS
Authors: HEMACHANDRA LANE A. , JAIN SANJAY
Published: November 2004

Polynomial-time positive reductions, as introduced by Selman, are by definition globally robust — they are positive with respect to all oracles. This paper studies the extent to which the theory of positive reductions remains intact when their global robustness assumption is removed. We note that two-sided locally robust positive reductions — reductions that are positive with respect to the oracle to which the reduction is made — are sufficient to retain all crucial properties of globally robust positive reductions. In contrast, we prove absolute and relativized results showing that one-sided local robustness fails to preserve fundamental properties of positive reductions, such as the downward closure of NP.
PROJECTIONS OF SEMICOMPUTABLE RELATIONS ON ABSTRACT DATA TYPES
Authors: TUCKER J.V. , ZUCKER J.I.
Published: November 2004

We consider projections of semicomputable relations on abstract structures We show that they arise in several contexts, including nondeterministic extensions of while programs with arrays by means of arbitrary initializations and random assignments. They form a basis for an investigation of the concept of algorithmic specifications of relations with nondeterministic search. An important technique in this investigation is the study of computation trees for imperative programs, in order to prove characterization theorems for semicomputable sets, of a form first developed by E. Engeler.
ALTERNATING TURING MACHINES WITH MODIFIED ACCEPTING STRUCTURE
Authors: INOUE KATSUSHI , ITO AKIRA , TAKANAMI ITSUO
Published: November 2004

We introduce an alternating Turing machine with modified accepting structure (denoted by MATM), which is an alternating Turing machine whose accepting condition differs from that of an ordinary alternating Turing machine (denoted by ATM). An MATM has a set of accepting state sets rather than a set of accepting states. An input word x is accepted by an MATM M if there is a computation tree of M on x such that the set of states associated with the leaves of the tree is equal to an accepting state set. Let UTM (MUTM) denote an ATM (MATM) with no existential state. We first investigate a relationship between ATM’s and MATM’s, and show that (i) for any function L(n), L(n) space bounded on-line (off-line) ATM’s are equivalent to L(n) space bounded on-line (off-line) MATM’s, and (ii) for any L(n) such that L(n)≥ log log n and limn→∞L(n)/n=0, L(n) space bounded on-line MUTM’s are more powerful than L(n) space bounded on-line UTM’s. We then investigate a relationship between online and off-line, and show for example that for any L(n) such that L(n)≥ log n and limn→∞L(n)/n=0, L(n) space bounded off-line MUTM’s are more powerful than L(n) space bounded on-line MUTM’s. We next show that there exists an infinite hierarchy among accepting powers of L(n) space bounded on-line (off-line) MATM’s and MUTM’s with L(n)≥ log log n and limn→∞L(n)/n=0. Finally, we investigate closure properties of space bounded on-line (off-line) MATM’s and MUTM’s.
A UNIFICATION ALGORITHM FOR THE λΠ-CALCULUS
Authors: PYM DAVID
Published: November 2004

We present a unification algorithm for the λΠ-calculus, the lambda calculus with first-order dependent function types. Our algorithm is an extension of Huet’s algorithm for the simply-typed lambda calculus to first-order dependent function types.

In the simply-typed lambda calculus one attempts to unify a pair of terms of the same type; in the λΠ-calculus types are dependent on terms so one must unify not only terms, but their types as well. Accordingly, we identify a suitable notion of similarity of types, and only attempt to unify a pair of terms of similar type: if the types are not similar then they are not unifiable. Since Huet’s algorithm does not enumerate all of the unifiers of a given pair of terms, the strategy of first unifying pairs of types — by identifying suitable pairs of subterms for unification — is not complete. Accordingly, we must unify terms and their types simultaneously, taking care to maintain all of the conditions that are necessary to ensure the well-formedness of the resulting calculated substitution.

Our notion of substitution is an algebraic one: substitutions are morphisms of λΠ-contexts. However, in order to define our algorithm we must work with psubstitutions and pcontexts — substitutions and contexts, respectively, in which variables are replaced by terms of similar, not β(η)-equal, type.
SOURCES OF NEURAL STRUCTURE IN SPEECH AND LANGUAGE PROCESSING
Authors: Stork David G.
Published: November 2004

Because of the complexity and high dimensionality of the problem, speech recognition—perhaps more than any other problem of current interest in network research—will profit from human neurophysiology, psychoacoustics and psycholinguistics: approaches based exclusively on engineering principles will provide only limited benefits. Despite the great power of current learning algorithms in homogeneous or unstructured networks, a number of difficulties in speech recognition seem to indicate that homogeneous networks taken alone will be insufficient for the task, and that structure—representing constraints—will also be required. In the biological system, the sources of such structure include developmental and evolutionary effects. Recent considerations of the evolutionary sources of neural structure in the human speech and language systems, including models of the interrelationship between speech motor system and auditory system, are analyzed with special reference to neural network approaches.
ASYMPTOTIC PROPERTIES OF A THIRD ORDER NEURAL NETWORK
Authors: Bengtsson Mats
Published: November 2004

We have investigated the storage capacity in the limit of large N (the network size) for a third order recurrent artificial neural network with Hebbian learning. Numerical results for the relation between the overlap to stored patterns, and the fraction of the number of stored patterns and N2 (the m—α relation), agree well with replica symmetric predictions. A comparative study is made of the m—α relation for a third and a second order network. Large differences exist between these two models, usually to the favour of the third order network. This result stands in some contrast to previous investigations. The phase transition temperature is investigated numerically and compared with mean field theory predictions.
MULTIPLE REPRESENTATIONS IN CONNECTIONIST SYSTEMS
Authors: Robins Anthony V.
Published: November 2004

This paper proposes an extension to the basic framework of distributed representation through the learning and use of different sorts of information—“multiple representations”—in connectionist/neural network systems. In current distributed networks units are typically ascribed only one “representing” or information carrying state (activation). Similarly, connections carry a single piece of information (a weight derived from the structure of the population of patterns). In this paper we explore units and connections with multiple information carrying states. In this extended framework, multiple distributed representations can coexist with a given pattern of activation. Processing may be based on the interaction of these representations and multiple learning processes can occur simultaneously in a network. We illustrate these extensions using (in addition to patterns of activation) “centrality distribution” representations. Centrality distributions are applied to two tasks, the representation of category and type hierarchy information and the highlighting of exceptional mappings to speed up learning. We suggest that the use of multiple distributed representations in a network can increase the flexibility and power of connectionist systems while remaining within the subsymbolic paradigm. This topic is of particular relevance in the context of the recent interest in the limitations of connectionism and the interface between connectionist and symbolic methods.
PIXE ANALYSIS OF INORGANIC ELEMENTS IN ATMOSPHERIC AEROSOLS AT GUANGZHOU
Authors: GUOSHU LI , HONG JIA , HUIMIN YIN , SHUPING DONG , HAIYAN GUO
Published: November 2004

Atmospheric aerosol samples were collected with eight-stage cascade impactors at five typical sites in Guangzhou. The samples were analyzed by the proton-induced X-ray emission (PIXE) technique. The mass concentrations and their size distributions for near 20 elements were obtained. Enrichment factors for coarse and fine modes of the elements were calculated. The sources of the elements and characteristics of atmospheric aerosols at Guangzhou were discussed; the results of mass concentrations for 15 elements in atmospheric aerosols were also compared with those in some other cities in China.
X-RAY PRODUCTION, INNER SHELL IONIZATION AND READING’S THEOREM IN ION · ATOM COLLISIONS
Authors: ISHII KEIZO
Published: November 2004

When a solid or gaseous target is bombarded with heavy charged particles, inner shell electrons of target atoms are ionized and characteristic x rays are produced. We can easily observe these x rays with a Si(Li) detector and derive inner-shell ionization cross section from the x-ray production cross sections. In this paper, we make a review of x-ray production, inner shell ionization and Reading’s theorem in light ion·atom collisions. This theorem is one of the most important ones in the ion·atom collision physics and permits precise discussion on comparison between experimental inner-shell ionization cross sections obtained with a Si(Li) detector and the calculations based on usual theories where the incident particle is assumed to interact with only one electron in an atom and the presence of other electrons is ignored.
ATOMIC COLLISIONS WITH HEAVY IONS—RECENT DEVELOPMENTS AT GSI
Authors: MOKLER P.H.
Published: November 2004

The interaction of very heavy ions with matter at high velocities is considered emphasizing bio-physical aspects. A status report on the new accelerator facility SIS-ESR including the raster scan system is given. First atomic physic experiments are reviewed. X-ray emission experiments, ion-electron recombination, and an experiment to the bound beta-decay are treated in more detail.
MICROPROBE ANALYSIS IN BIOLOGICAL SAMPLES
Authors: PALLON JAN
Published: November 2004

During the last few years, the nuclear microprobe has demonstrated itself as a strong research facility in the application to biological samples. The performance is not without competition from new techniques, and to maintain special advantages of the nuclear microprobe, care must be taken in the selection and preparation of the biological samples to analyse.
LIQUID TARGET FOR EXTERNAL PIXE ANALYSIS
Authors: CHOU C.F. , YU C. , HSU C.C.
Published: November 2004

A simple method for preparing liquid target with uniform thickness is proposed for external PIXE analysis. The standard sample prepared by this method can help us to make quantitative analysis of the liquid samples.
DATA SMOOTHING TECHNIQUES APPLIED TO PROTON MICROPROBE SCANS OF TELEOST HARD PARTS
Authors: WEST I.F. , COOTE G.E. , GAULDIE R.W.
Published: November 2004

We use a proton microprobe to examine the distribution of elements in otoliths and scales of teleost (bony) fish. The elements of principal interest are calcium and strontium in otoliths and calcium and fluorine in scales. Changes in the distribution of these elements across hard structures may allow inferences about the life histories of fish.

Otoliths and scales of interest are up to a centimeter in linear dimension and to reveal the structures of interest up to 200 sampling points are required in each dimension. The time needed to accumulate high X-ray counts at each sampling point can be large, particularly for strontium. To reduce microprobe usage we use data smoothing techniques to reveal changing patterns with modest X-ray count accumulations at individual data points.

In this paper we review performance for revealing pattern at modest levels of X-ray count accumulations of a selection of digital filters (moving average smoothers), running median filters, robust locally weighted regression filters and adaptive spline filters.
EXPERIMENTAL ARRANGEMENTS FOR NON-VACUUM BIO-PIXE
Authors: RAISANEN J.
Published: November 2004

The experimental arrangements used for external beam PIXE analysis of biomedical samples are surveyed. Emphasis is given to the instrumental and physical aspects of the various measuring systems. Special features of the setups and other means of obtaining optimal measuring conditions play an important role in many cases. The proper choice of bombarding proton energy and the minimization of the system background radiation make significant contributions to the sensitivity obtainable by the technique. Parameters such as exit foil materials, setup cons- truction materials, gas atmosphere used (eg. He, air), beam current normalization and system geometry are of specific interest. Some typical recent examples in the field are given.
MICRO-PIXE ANALYSIS OF FISH OTOLITHS: METHODOLOGY AND EVALUATION OF FIRST RESULTS FOR STOCK DISCRIMINATION
Authors: SIE SOEY H. , THRESHER RONALD E.
Published: November 2004

Micro-PIXE has been used to measure the trace element distribution in otoliths from several species of ocean fish, in order to investigate its possible use in stock discrimination. Trace elements detected include Sr, Fe, Mn, Ni, Zn, Cu, Se, Cd, Br, Hg and Pb. Trace elements Na, K, Cl, S and Cl were detected with the electron microprobe. The high sensitivity of PIXE demands a meticulous sample preparation procedure to avoid contamination problems. Practical problems associated with the application of the technique were investigated in detail. Preliminary results indicate that most trace elements except Sr, are present at close to the limits of detection at few ppm, but biologically significant data can be obtained for stock discrimination applications.
PIXE MEASUREMENT OF THE CADMIUM CONTENT IN ANIMAL TISSUES
Authors: QUYNH LE HUONG , DEMETER I. , HOLLÓS-NAGY K. , SZŐKEFALVI-NAGY Z.
Published: November 2004

PIXE measurements were performed on thin samples prepared from different rabbit liver, kidney, muscle and bone tissues. The trace element concentrations obtained were compared to those measured by atomic absorption spectrometry. The PIXE detection limit for Cd was found to be 0.7 ppm.
A COMPARISON OF FOSSILIZED DINOSAUR BONE AND THE SURROUNDING ROCK USING PIXE ANALYSIS
Authors: NEILSEN D.W. , REES L.B. , MANGELSON N.F. , HILL M.W.
Published: November 2004

Six samples of fossilized dinosaur bone and surrounding rock were analyzed by PIXE to investigate general relations between the bone and rock. The powdered samples were brought into an acid solution by a lithium metaborate fusion process. The data were analyzed with chemometric methods to successfully differentiate the bone samples from the complementary rock samples. The Sr/Ca ratio is consistently higher in fossilized bone than the surrounding rock. Ba, Y and U, when found in the rock, appear in significantly higher concentrations in the bone. S and Ti, elements commonly found in rock samples, are not found in the bone samples.
PIXE STUDY ON INHIBITION EFFECT OF SODIUM ALGINATE TO THE ABSORPTION OF STRONTIUM
Authors: PEI MA XIN
Published: November 2004

The sodium alginate extracted from sargassum of South China Sea significantly inhibited the absorption of Sr in human gastrointestinal tract. Because of the identical metabolism dynamics of radioactive Sr and stable Sr, oral medication experiments have been performed by using stable Sr as a tracer. Fifteen adult healthy subjects (10 males and 5 females) were involved and divided into two groups. Concentrations of Sr, Ca, Fe, Cu, and Zn in serum and urine (24 hours) at different times after oral medications were measured by PIXE. It was found from the PIXE results that Sr in serum and in urine were reduced (78 +/− 8.9)% and (78 +/− 11)% respectively by sodium alginate. A reasonable dosage of sodium alginate had little influence to the absorption of Ca, Fe, Cu, and Zn.
TRACE ELEMENTS IN HUMAN BLOOD: ALTERATIONS ASSOCIATED WITH MYOCARDIAL INFARCTION
Authors: PINHEIRO T. , MAENHAUT W. , WÄTJEN U. , HALPERN M.J.
Published: November 2004

The alteration of concentration levels for two minor elements (K and Ca) and 7 trace elements (Mn, Fe, Cu, Zn, Se, Rb and Pb) in serum and packed blood cells was investigated. The samples originated from 35 patients that had a myocardial infarction and from 29 healthy individuals. The Mn and Pb concentrations were only determined in packed blood cells. Particle-induced X-ray Emission (PIXE) was used to determine the elemental concentrations in the various samples. In blood serum the Fe, Cu and Zn concentrations were found to be altered from normal, while in packed blood cells significant differences were encountered for Ca, Mn, Fe, Cu, Se and Pb. Factor analysis performed on the serum and packed blood cells data matrices revealed one factor for each sample type which allowed distinguishing between healthy and pathological individuals. Furthermore, the elements that permit this discrimination are different for the two data sets. The elements related to this discrimination factor were Fe and Cu for serum and Ca, Mn, Fe, Cu and Zn for packed blood cells.
TRACE ELEMENT ANALYSIS OF ENVIRONMENTAL SAMPLES BY NUCLEAR ANALYTICAL TECHNIQUES
Authors: MAENHAUT WILLY
Published: November 2004

The recent methodological developments and particularly the recent applications of nuclear analytical techniques (mainly PIXE and INAA) for measuring minor and trace elements in various types of environmental samples are reviewed. The sample types covered range from atmospheric aerosols over miscellaneous air topics (e.g., emissions, wet and dry deposition) to various solid environmental materials and samples from the aqueous environment. A fairly comprehensive overview is given of the research on atmospheric aerosols. For the other sample types, the trends in the research are indicated and selected examples of applications are presented. It is shown that the nuclear analytical techniques are very valuable for the multielement analysis of solid environmental samples. Furthermore, PIXE is particularly suitable for analyzing atmospheric aerosol samples.
REFERENCE MATERIALS FOR MICRO-ANALYTICAL NUCLEAR TECHNIQUES
Authors: Valkovic V. , Zeisler R. , Bernasconi G. , Danesi P.R.
Published: November 2004

Direct application of many existing reference materials in micro-analytical procedures such as energy dispersive x-ray fluorescence (EDXRF), particle induced x-ray emission spectroscopy (PIXE) and ion probe techniques for the determination of trace elements is often impossible or difficult because: 1) other constituents present in large amounts interfere with the determination; 2) trace components are not sufficiently homogeneously distributed in the sample. Therefore specific natural-matrix reference materials containing very low levels of trace elements and having high degree of homogeneity are required for many micro-analytical procedures. In this report, selection of the types of environmental and biological materials which are suitable for micro-analytical techniques will be discussed.
PIXE ANALYSIS OF NEEDLES FROM FUMIGATED NORWAY SPRUCE
Authors: KEMP K. , MORTENSEN L. , RO-POULSEN H.
Published: November 2004

Norway spruce is fumigated with O3, SO2, and NO2 in open-top chambers. The spruce needles from the first two years of fumigation were analysed by means of PIXE. A total of 14 elements were found in concentrations above the detection limits in the major part of the around 150 samples analyzed. The results were used in an analysis of variance showing, slightly increased levels of S and Zn in needles from trees exposed to fumigation with all three gases.
EARLY ASSESSMENT OF DESIGN, PACKAGING AND TECHNOLOGY TRADEOFFS
Authors: LAPOTIN DAVID P.
Published: November 2004

This paper discusses the early design analysis of large computer systems and presents techniques and models for evaluating the matching between a proposed machine design and an MCM packaging technology. It shows that an early design specification, coupled with a prediction tool, can provide valuable insight into limitations and specific design problem areas, which often only becomes apparent much later in the product cycle. A detailed discussion of the tradeoff between machine performance and package specifications is given along with the details of an interactive early analysis methodology. Detailed models are presented for the early analysis of transmission line constraints, chip placement and coupled noise.
THE VAX 9000 MULTICHIP PACKAGING AND ITS EVOLUTION TO FUTURE HIGH END COMPUTER APPLICATIONS
Authors: HO CHUNG W.
Published: November 2004

The design and process of Digital Equipment Corporation’s VAX 9000 multichip packaging, the MCU (Multichip Unit), is reviewed in some detail. A set of projected future high speed bipolar ECL chip characteristics, in technology improvement increments, is then presented. These characteristics lead to some specific multichip packaging requirements. The corresponding designs of MCU evolutions/extensions are proposed and discussed for meeting the requirements. One major conclusion of the paper is that the present VAX 9000 MCU technology can be extended for several generations of future high end computer applications.
TRANSIENT SIMULATION OF LOSSY COUPLED TRANSMISSION LINES CHARACTERIZED WITH FREQUENCY-DEPENDENT PARAMETERS
Authors: CHANG FUNG-YUEL , WING OMAR
Published: November 2004

The method of characteristics is generalized to simulate the transient response of coupled transmission lines, which are characterized with frequency-dependent parameters. The discrete-time transient simulation is carried out from the equivalent decoupled transmission lines with an arbitrary set of characteristic impedances. The method eliminates the time-consuming convolution integration and has been adapted for iterative waveform relaxation simulation using the Fast Fourier Transform (FFT) for reduction of simulation cost. Examples are given to substantiate the accuracy and the efficiency of both discrete-time and waveform relaxation simulations.
SINGULAR CURVES AND THE PLATEAU PROBLEM
Authors: HASS JOEL
Published: November 2004

Douglas and Rado showed that an embedded rectifiable curve bounds a disk of least area. It is shown that this result holds for all rectifiable curves, including singular ones.
MAXIMAL TORUS ACTIONS ON SOLVMANIFOLDS AND DOUBLE COSET SPACES
Authors: LEE KYUNG BAI , RAYMOND FRANK
Published: November 2004

Any compact, connected Lie group which acts effectively on a closed aspherical manifold is a torus Tk with k ≤ rank of [Formula: see text], the center of π1 (M). When [Formula: see text], the torus action is called a maximal torus action. The authors have previously shown that many closed aspherical manifolds admit maximal torus actions. In this paper, a smooth maximal torus action is constructed on each solvmanifold. They also construct smooth maximal torus actions on some double coset spaces of general Lie groups as applications.
ON THE K-THEORY OF QUARTER-PLANE TOEPLITZ ALGEBRAS
Authors: PARK EFTON , SCHOCHET CLAUDE
Published: November 2004

Given a C*-algebra A which is filtered by a collection of closed ideals Ai, there is a spectral sequence which relates the K-theory of A to the K-theory of the various quotient algebras Ai/Ai−1. The d1 differentials in this spectral sequence are familiar index invariants, but the higher differentials are not well-understood. Considering the case of Toeplitz C*-algebras associated with certain cones in Z2, it is shown that a d2 differential in the spectral sequence is non-trivial. This differential turns out to be an obstruction to a classical lifting problem in operator theory. Analysis of this obstruction leads to necessary and sufficient conditions for the lifting problem. It is hoped that this example will illuminate the role of higher differentials in the K-theory spectral sequence.
INTEGRAL REPRESENTATIONS FOR LOCALLY DEFINED POSITIVE DEFINITE FUNCTIONS ON LIE GROUPS
Authors: JORGENSEN PALLE E. T.
Published: November 2004

It is well known that locally defined positive definite functions on Lie groups G generally do not extend to positive definite functions which are defined on the whole group. We introduce two stronger positivity concepts for locally defined functions, and show that they are equivalent to extendability. We then apply this to the case when G is the Heisenberg group. When an additional symmetry is imposed, we obtain a complete spectral analysis of the (locally defined) positive definite functions. The methods of proof are based on unitary dilation techniques (i.e., carefully chosen extensions of some underlying Hilbert space associated to the problem), and on spectral theory for noncommuting operators.
C*-ALGEBRAS OF SINGULAR INTEGRAL OPERATORS AND TOEPLITZ OPERATORS ASSOCIATED WITH n-DIMENSIONAL FLOWS
Authors: MUHLY PAUL S. , XIA JINGBO
Published: November 2004

For a given covariant representation π of an n-dimensional dynamical system (X, R n, α), we study the C*-algebras [Formula: see text] of abstract singular integral opertors and Toeplitz operators generated by π(C(X)) and Hilbert transforms corresponding to n linearly independent directions. Such an algebra has a chain of ideals [Formula: see text]. We compute all [Formula: see text] and show that for 0≤k≤n−1 each of these quotients is the direct sum of C*-algebras which can be thought of as [Formula: see text] for flows of lower dimensions. The ideal structure of [Formula: see text] is carefully studied. We also determine precisely when [Formula: see text] is a C*-algebra of type I.
High Spatial Resolution Using the Conventional Particle-Mesh Technique
Authors: BIEN R. , FUCHS B. , WIELEN R.
Published: November 2004

The use of the particle-mesh technique has a long and successful history in the field of computer simulations of collisionless gravitational systems, such as galaxies. Since the method allows the treatment of large numbers of particles statistical noise has only a small effect. On the other hand, severe problems arise when high density peaks must be resolved.

In order to master these difficulties we have worked out a procedure which is an extension of the standard particle-mesh code in three-dimensional Cartesian coordinates. The basic idea is simply to introduce additional grids and sub-grids in regions with steep density gradients such that the system of grids is re-arranged at each integration step. In this way we are able to simulate single and interacting galaxies.

In the present paper a short review of some frequently used methods of galaxy simulations is given and our own method is outlined.
ASTRID: A Programming Environment for Physicists
Authors: BONOMI E. , FLÜCK M. , GRUBER R. , HERBIN R. , RICHNER T. , SCHMID V. , TRAN C.T. , MERAZZI S.
Published: November 2004

The purpose of the ASTRID project [1] is to combine the effort of the scientific community in the development of a software system for simulation and modeling of physical phenomena that meets the requirements of the users. This system includes the data management system MEMCOM [2], the ASTRID command language [3], the three-dimensional graphics system VIEW [4], the ASTRID finite element solver [5] and a few utility programs to interface user defined modules to the ASTRID data structure.
Portability and Reusability, Standardized Programming for Present and Future Computers
Authors: DUMONT JEAN-JACQUES , TOMASSINI MARCO
Published: November 2004

Unstructured sequential programming in Fortran, together with a top down approach for problem analysis, have always been and still are the usual physicists favorite methods as far as computing is concerned. This unfortunate fact of life is causing a tremendous amount of efficiency loss for code development and maintenance, which could easily be avoided by evolving to a more modern, bottom up programming style, based on the new emerging standards (system interfaces, communication between computational nodes, object-oriented C-extensions, user graphical interfaces, data structures etc.). We are reaching the historical point where this evolution becomes mandatory if one wants to tackle properly the problem of programming in a reasonably efficient way the highly parallel machines which are now appearing on the market, to the delight of numerous scientists who are badly in need of more computation power.
Influence of the Back-Jump Correlations on the Fermi-Dirac Statistics
Authors: BARSZCZAK T. , KUTNER R.
Published: November 2004

The influence of the essential Bardeen-Herring back-jump correlations on the Fermi-Dirac statistics is studied by the Monte Carlo simulation technique and semi-analytically.
Nosé-Hoover Molecular Dynamics Simulations of the Pipe-Diffusion Mechanism in Gold Using Many-Atom Forces
Authors: BOEHM J. VON , NIEMINEN R.M.
Published: November 2004

This paper presents: a) A generalization of the velocity-Verlet algorithm to solve the Nosé-Hoover equations of motion. b) A method to follow vacancies in low symmetry condensed matter systems. c) Some preliminary results on the pipe-diffusion mechanism in gold.
Compressible Flow Simulations on a Massively Parallel Computer
Authors: ORAN ELAINE S. , BORIS JAY P.
Published: November 2004

This paper describes model development and computations of multidimensional, highly compressible, time-dependent reacting on a Connection Machine (CM). We briefly discuss computational timings compared to a Cray YMP speed, optimal use of the hardware and software available, treatment of boundary conditions, and parallel solution of terms representing chemical reactions. In addition, we show the practical use of the system for large-scale reacting and nonreacting flows.
The Phases of Cyclohexane Predicted by MD Simulation
Authors: TREW A.S. , WILDING  , PAWLEY G.S.
Published: November 2004

Phase changes in cyclohexane have been studied by MD simulation on the AMT DAP computer, using a zero-pressure technique to simulate clusters of 512 molecules. This work builds upon a previous study [1] in which we performed MD calculations on a smaller sample and found a phase intermediate between the experimentally determined low temperature crystalline structure (C2/c) and the high temperature plastic one (Fm3m). This new phase had not been observed experimentally in the bulk at ambient pressure [2]. We determined the intermediate structure to be rhombohedral with a space group of [Formula: see text].

A subsequent neutron diffraction study of cyclohexane at high pressures (< 5) kbar has permitted the identification of two orthorhombic phases [3] which occur for deuterated cyclohexane. In addition, for very small sample sizes another, as yet unidentified, phase has been observed at ambient pressure [4]: clear evidence that there are differences between the crystal structure in the bulk and in small clusters. We therefore decided to extend our earlier work in order to investigate the behaviour of the phase as a function of sample size.

Using a larger sample we find behaviour much closer to that seen in the bulk material. The rhombohedral structure is still observed but over a very much reduced temperature range and the transition temperatures are closer to those seen experimentally. Although -we cannot identify the structure observed by Bosio and Dumas [4] with that simulated it is clear that there is an obvious parallel with the behaviour of the model. A further study of this system is underway.
THE SIZE OF A RANDOM SURFACE
Authors: HEERMANN DIETER W.
Published: November 2004

The size of a random surface can be measured in at least two ways from two lengths: the radius of gyration and the smallest length such that a box constructed with this length contains the surface. In this paper it is shown that both lengths are non-self-averaging.
AN EFFICIENT MULTI-SPIN CODING ALGORITHM FOR NEURAL NETWORKS
Authors: NESCHEN MARTIN
Published: November 2004

A new method for large-scale numerical simulations of neural networks is proposed which reduces the computational effort by incrementally updating the local fields and thus restricting the operations to flipped spins only. A highly optimized multi-spin algorithm is described employing words oriented along the columns of the coupling matrix unlike the horizontal structure in existing high-speed algorithms. An effective rate of 35*109 couplings/s on a Cray-YMP can be attained which is about five times as fast as best existing multi-spin implementations.
SPECIFYING CONTROL SIGNALS FOR SYSTOLIC ARRAYS BY UNIFORM RECURRENCE EQUATIONS
Authors: XUE JINGLING
Published: November 2004

Starting with a system of uniform recurrence equations (source UREs) for a systolic design, we provide a method that allows a specification of control signals by another system of UREs (control UREs), which has no notion of time and space. Necessary and sufficient conditions for the correctness of the control UREs are stated. The standard space-time mapping technique is extended so that systolic arrays with a description of both data and control flow are directly synthesised from the source and control UREs. Optimisations of control signals are discussed. An example is provided.
ON LOWER BOUNDS FOR THE COMMUNICATION VOLUME IN DISTRIBUTED SYSTEMS
Authors: RANAWAKE U. A. , LENDERS P. M. , GOODNICK S. M.
Published: November 2004

In this paper we derive a lower bound for the total communication volume when mapping arbitrary task graphs onto a distributed processor system. For a K processor system this lower bound can be computed with only the K (possibly) largest eigen values of the adjacency matrix of the task graph and the eigen values of the adjacency matrix of the processor graph. We also derive the eigen values of the adjacency matrix of the processor graph for a hypercube multiprocessor and illustrate the concept with a simple example for the two processor case.
CONSTANT DELAY PARALLEL COUNTERS
Authors: AKL SELIM G. , DUBOUX THIBAULT , STOJMENOVIC IVAN
Published: November 2004

We present a cost-optimal parallel algorithm for generating variations of m elements out of {0, 1, …, n - 1} in lexicographic order. It uses a linear array of m processors, each having constant size memory and each being responsible for producing one part of a given variation. Binary and decimal counters are special cases of the algorithm, when n = 2 and n = 10, respectively. To our knowledge, the algorithm presented here is the first to be published with the property that the delay between any two variations generated is constant.