bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis A in workers exposed to sewage: a systematic review
Authors: Glas C , Hotz P , Steffen R
Published: July 2002

OBJECTIVES

To assess whether the scientific literature supports the hypothesis that workers exposed to sewage are at higher risk of hepatitis A (HA).

METHODS

All original papers reporting epidemiological studies published in English, French, or German which reported on the risk of HA infection in workers exposed to sewage were eligible. They were identified by several methods and each original paper was assessed independently with a checklist by two people. Studies were classified according to the strength of their design. Non-eligible studies were also examined to assess the impact of publication bias. If the risk estimates diverged widely, causes for heterogeneity were assessed. A distinction was made between seroprevalence studies based on subclinical HA (defined only by the presence of anti-HA antibodies) and clinical HA.

RESULTS

17 eligible studies were identified. No indication of an increased risk of clinical HA could be found. For seroprevalence the studies with the strongest design suggested a slightly increased risk of subclinical HA with an odds ratio (OR) <2.5. Heterogeneity was considerable and precluded a meta-analysis. Considering non-eligible studies would still decrease the OR.

CONCLUSIONS

The systematic review does not confirm an increased risk of clinical HA in workers exposed to sewage. An increased risk of subclinical HA cannot be excluded but the association between seropositivity and exposure to sewage was not strong and became still weaker if publication bias was taken into account.
Sensitisation to natural rubber latex: an epidemiological study of workers exposed during tapping and glove manufacture in Thailand
Authors: Chaiear N , Sadhra S , Jones M , Cullinan P , Foulds I S , Burge P S
Published: July 2002

OBJECTIVES

To estimate the prevalence of sensitisation to natural rubber latex in latex tappers and latex glove factory workers, and to relate this to airborne exposure to latex.

METHODS

Five hundred workers employed in three latex glove factories, 314 tappers, and 144 college students (control group) were studied. The workers in the glove factories were classified into three exposure groups; high, moderate, and low. Personal exposures to natural rubber latex aeroallergens were measured by immunoassay. Symptom questionnaires and skin prick tests with latex allergens (Stallergènes 1:200 w/v) and other common environmental allergens were performed. The criterion for positivity was a wheal reaction at least 3 mm in diameter greater than that to a diluent control.

RESULTS

The geometric mean (GM) concentration of latex in air was 15.4 μg/m3for those employed in glove stripping, glove inspections, and packing of powdered gloves. The moderate exposure glove manufacturing group and the tappers had GM concentrations of 2.3 and 2.4 μg/m3respectively, compared with United Kingdom users of latex powdered gloves,who had GM concentrations of 0.5 μg/m3. The prevalence of sensitisation to latex in the tappers and latex glove factory workers was 1.3% and 1.7% respectively. No positive cases were found among the college students. Workers who showed a positive skin prick test to latex were more likely to be atopic. Work related respiratory and dermatological symptoms were found in about 20% of each population studied, but were not related to the presence of positive latex prick tests.

CONCLUSIONS

This study suggests that in the Thai latex industries, latex sensitisation is rare despite high concentrations of airborne exposure and is less prevalent than in the healthcare sector in Europe where skin exposure is greater.
Changes in rates and severity of compensation claims for asthma due to diisocyanates: a possible effect of medical surveillance measures
Authors: Tarlo S M , Liss G M , Yeung K S
Published: July 2002

Objectives: A medical surveillance programme was introduced into Ontario for workers exposed to diisocyanates in 1983, but no mandated surveillance programme is in effect in this province for other occupational respiratory sensitisers. This study assesses changes in incidence and severity of compensated claims for occupational asthma (OA) due to diisocyanates compared with other causes, which have occurred since the introduction of this surveillance programme.

Methods: New claims for OA compensated by the Ontario Workers' Compensation Board (WCB) between 1980 and 1993 were retrospectively reviewed. Linkage was made between these data and an Ontario Ministry of Health database to assess hospital admissions for asthma from the date of onset of OA until the end of 1996.

Results: Numbers of claims for OA induced by diisocyanates ranged from 9–15/year in 1980–83, increased up to 55–58 claims/year in 1988–90, then fell to 19–20 claims/year by 1992–93. By contrast yearly numbers of claims for OA due to other causes increased up to 1985–87 then remained relatively stable. Duration of symptoms for OA induced by diisocyanates was shorter than for other claims and there were fewer hospital admissions among those with OA induced by diisocyanates than among those with OA induced by other causes. Occupational asthma from all causes was diagnosed earlier in claims for 1987–93 compared with 1980–86, and indicators of severity of asthma were also milder in accepted claims during 1987–93 than in earlier claims.

Conclusions: Although engineering and industrial hygiene measures may have contributed to these changes, our findings are also consistent with a beneficial contribution from the medical surveillance programme for workers exposed to diisocyanates.
Silent myocardial ischaemia in patients with proved coronary artery disease: a comparison of diabetic and non-diabetic patients
Authors: Ditchburn C J , Hall J A , de Belder M , Davies A , Kelly W , Bilous R
Published: July 2002

OBJECTIVE

To determine whether diabetic patients with coronary artery disease are more likely to experience silent myocardial ischaemia than subjects without diabetes.

SUBJECTS

Patients undergoing coronary angiography at a regional cardiothoracic unit, identified as having diabetes from the local district diabetic register/database.

DESIGN

The coronary angiograms and exercise treadmill tests of 100 diabetic and 100 non-diabetic patients who all had significant coronary artery disease and maximal effort exercise tests were reviewed. Patients were individually matched for age group, gender, severity of coronary artery disease, and indication for treadmill test.

OUTCOME MEASURES

Significant coronary artery disease was defined as a stenosis of greater than 50% diameter in at least one of the major coronary artery segments. Exercise tests were graded as positive if the electrocardiographic (ECG) recording showed planar or downsloping ST segment depression of ⩾1 mm in more than two leads at 80 ms post J-point or if there was a blood pressure fall ⩾10 mm Hg after an initial rise. A negative exercise test was defined as one in which the subject experienced no pain, had no ECG changes after maximal effort and had a normal blood pressure response. Subjects who did not experience any form of typical angina-type pain during a positive exercise test were defined as having an episode of silent ischaemia. Patients with symptomatic ischaemia were those who experienced typical angina-type pain with accompanying ST segment changes. Patients with a negative exercise test were defined as having “undetermined ischaemia”. This category included all those without ECG evidence of myocardial ischaemia during the exercise test (with or without accompanying chest pain).

RESULTS

In the diabetic patients, 34% had ECG evidence of silent ischaemia on treadmill testing compared with only 19% of the non-diabetic controls (p<0.02).

CONCLUSIONS

This study shows that diabetic patients with proved coronary artery disease have a higher risk of developing silent myocardial ischaemia during exercise than non-diabetic patients.
Seasonal changes in chlorophyll fluorescence quenching and the induction and capacity of the photoprotective xanthophyll cycle in Lobaria pulmonaria
Authors: MacKenzie Tyler DB , Król Marianna , Huner Norman PA , Campbell Douglas A
Published: July 2002

Lobaria pulmonaria (L.) Hoffm. survives large changes in ambient light and temperature between winter and summer in temperate deciduous forests. Potential photosystem II (PSII) electron transport, measured at 20°C using chlorophyll fluorescence analysis, was consistent in thallus samples taken in March and August from a temperate deciduous forest, while the potential for nonphotochemical quenching (NPQ) was higher in March than in August. NPQ was, however, similar in March and August in a population from a coniferous site with a permanently closed canopy. Thalli measured at a typical March field temperature showed a depression of PSII electron transport, qp and gross CO2 uptake and a rise in realized NPQ. Xanthophyll cycle pigments were more abundant in the March than in the August samples in the deciduous forest populations but did not change significantly in the permanently closed-canopy population. In August, relatively low NPQ correlated with xanthophyll pool size in the deciduous forest samples. The more intense NPQ derived from low temperature and low CO2-electron demand in the March samples, however, was not correlated with xanthophyll pool size. Thus, most of the NPQ observed in the high light exposure March samples was not explained by variation in xanthophyll pool size.Key words: carotenoids, excitation quenching, lichen, nonphotochemical quenching, PSII electron transport.
Root storage proteins, with particular reference to taproots
Authors: Bewley J Derek
Published: July 2002

The presence of storage proteins has been reported in roots of several perennial and biennial weed and crop species, and particularly in members of the Compositae, Euphorbiaceae, and Leguminosae. In some species the amount of these root proteins fluctuates seasonally, increasing in the fall and winter months and declining in the spring and early summer. Also, the root proteins may decline during regrowth of decapitated plants. The evidence that these proteins play a role as storage proteins is frequently only circumstantial; moreover, they are usually only a relatively minor component of the total nitrogen pool within the root. Only one root protein, that from the dandelion taproot, has been extensively characterized, and it has no properties in common with known vegetative storage proteins. The literature on root proteins is reviewed, with particular emphasis on those present in taproots. The paucity of definitive data allows few conclusions to be reached, and more research is required to establish the role, nature, and importance of root proteins.Key words: taproots, perennial weeds, root proteins, nitrogen pools, storage proteins.
Gene expression of immunomodulatory cytokines induced byNarcissus tazettalectin in the mouse
Authors: Ooi Linda S.M , Liu Fang , Ooi Vincent E.C , Ng T B , Fung M C
Published: July 2002

The immunomodulation of Narcissus tazetta lectin (NTL) on the induction of gene expression of cytokines in the mouse was studied using specific cytokine primers, total RNA isolated from mouse splenocytes and macrophages, and reverse transcription  polymerase chain reaction (RT-PCR). For comparison, a fungal antimitogenic lectin from Agaricus bisporus (ABL) was used to test and compare the acute (kinetic) induction of cytokine gene expression. NTL was able to induce the expression of IL-1β, TNF-α, and immunoreactive nitric oxide synthase (NOS) in both splenocytes and macrophages in vivo after 10-day consecutive peritoneal injections of 5 mg NTL·kg1·day1in the mouse. Nevertheless, the expression levels of IFN-γ and TGF-β were markedly increased in macrophages, and the levels of IL-2 and IL-4 were up-regulated only in splenocytes. From the kinetic pattern of cytokine induction and gene expression, ABL appeared to induce the up-regulation of IL-1β and TNF-α in splenocytes up to 24 h, whereas NTL showed a more sustained effect on the expression of these cytokines in macrophages. While NTL manifested TGF-β expression at the onset of 12 and 24 h in macrophages and splenocytes, respectively, ABL induced TGF-β in neither splenocytes nor macrophages. After injection of NTL, stem-cell factor was clearly down-regulated in macrophages at 24 and 48 h but up-regulated in splenocytes at the end of 24 h. The immunopotentiating effect of NTL is quite similar to that of LZ-8, a fungal immunomodulatory lectin isolated from the Chinese premier medicinal mushroom Ganoderma lucidium. However, the mechanism of immunomodulation of NTL still awaits to be elucidated.Key words: immunomodulation, cytokine genes, mannose-binding lectin, Narcissus.
Trembling aspen site index in relation to environmental measures of site quality at two spatial scales
Authors: Chen Han YH , Krestov Pavel V , Klinka Karel
Published: July 2002

To evaluate the variation in trembling aspen (Populus tremuloides Michx.) productivity at a large geographic scale, we examined the relationships between site index and environmental factors from 142 even-aged, fully stocked stands located on a variety of sites across interior British Columbia. Site index was derived from stem analysis and the environmental measures included climate surrogates (latitude, longitude, and elevation), biogeoclimatic zone, slope aspect, actual soil moisture regime (SMR), and soil nutrient regime (SNR). The spatial gradients (latitude, longitude, and elevation), slopeaspect, SMR, and SNR affected aspen site index, but their relationships greatly varied with biogeoclimatic zone. At the provincial scale, these relationships were weaker than on the zonal scale. Among the models developed for predicting aspen site index, we recommend the zone-specific all-factor model for application, which explained 82% of the variation of site index and provided unbiased and precise predictions.
Geographic variation in resin canal defenses in seedlings from the Sitka spruce × white spruce introgression zone
Authors: O'Neill G A , Aitken S N , King J N , Alfaro R I
Published: July 2002

Seedlings from 18 provenances along a coast-interior transect in the Picea sitchensis (Bong.) Carrière × Picea glauca (Moench) Voss introgression zone in northwestern British Columbia were mechanically wounded at the beginning of their third growing season to simulate natural attack by the white pine weevil, Pissodes strobi (Peck). Constitutive resin canals (CRC) in the cortex and traumatic resin canals (TRC) in the xylem of terminal shoots were characterized microscopically 4 months after wounding. Wounding resulted in a large increase in CRC size and in TRC number and density. Provenances differed significantly in TRC number and in CRC number, size, total area, and the proportion of total bark area occupied by CRC. CRC number and size, TRC number, and provenance weevil resistance (obtained from previously published data) increased with increasing latitude, elevation, and distance from the Pacific Ocean (i.e., towards the P. glauca end of the introgression zone) and decreased with increasing longitude (i.e., towards P. sitchensis). These traits also increased with aridity and continentality and decreased with most temperature, precipitation, and growing season length variables. Statistically significant multiple regression models related variation in some resin canal traits to geographic (r2 = 0.71) and climatic (r2 = 0.62) variables. Provenance mean values for weevil resistance were positively associated with predicted values for TRC number and CRC size. These results indicate that it is possible to predict locations in the introgression zone containing trees that possess desirable resin canal traits using geographic or climatic variables.
Sequential alternation of offspring sex from successive eggs by female green anoles, Anolis carolinensis
Authors: Lovern Matthew B , Passek Kelly M
Published: July 2002

We examined the relationships between maternal size, breeding season stage, and offspring sex at hatching for the oviparous lizard Anolis carolinensis. Specifically, we tested two hypotheses: (1) large females produce offspring with male-biased sex ratios and small females produce offspring with female-biased sex ratios; and (2) females, regardless of size, produce offspring with male-biased sex ratios early in the breeding season and female-biased sex ratios late in the breeding season. We found no support for either hypothesis. Rather, we found that individual females of all sizes and throughout the breeding season alternated offspring sex of sequentially laid eggs. Because female anoles also alternate the ovary that produces successive eggs, we tested a third hypothesis: females produce eggs of only one sex with each ovary. Both palpation to track which ovary produced which eggs, and unilateral ovariectomies, leaving females with only one functioning ovary, failed to support this hypothesis. Regardless of whether an ovary was removed, females were capable of producing both male and female offspring from either ovary. To account for this and potentially other unusual patterns of offspring production, we provide evidence that maternal hormone levels around the time of fertilization may affect offspring sex.
Variation in growth of Brown-headed Cowbird (Molothrus ater) nestlings and energetic impacts on their host parents
Authors: Kilpatrick A Marm
Published: July 2002

I tested several hypotheses about the plasticity of avian growth by comparing growth of Brown-headed Cowbird (Molothrus ater) nestlings in 20 different host species. Growth of cowbird nestlings was not strongly correlated with host adult mass and nearly all hosts were able to provision cowbirds with enough food to grow at nearly the highest observed rate. Cowbird growth was positively correlated with site latitude (which negatively covaried with maximum temperature) and negatively correlated with the nestling period of the host species. The metabolizable energy expenditure of cowbird and host nestlings was estimated as an approximate measure of the food provisioned by parents. As host adult mass varied from 6 to 113 g, one cowbird nestling was equivalent to 3.40.56 host nestlings in terms of peak daily energy intake. Cowbird nestlings impose a substantial energetic demand on smaller host parents that may reduce their future survival or fecundity. The quantity of energy delivered to parasitized nests demonstrates that parents are often willing to provision nests at a much higher rate than for an average clutch of their own young.
REMARKS ON A QUERY-BASED VARIANT OF THE PARALLEL REPETITION THEOREM
Authors: VERBITSKY OLEG
Published: July 2002

The Parallel Repetition Theorem says that n-fold parallel execution of a two-prover one-round interactive proof system reduces the error probability exponentially in n. The bound on the error probability of the parallelized system depends on the error probability and the answer size of the single proof system. It is still unknown whether the theorem holds true with a bound depending only on the query size. This kind of a bound may be preferable whenever the query size is considerably smaller than the answer size, what really happens in some cryptographic protocols. Such a bound is only known in the case that queries to the provers are independent. The present paper extends this result to some cases of strong correlation between queries. In particular, a query-based variant of the Parallel Repetition Theorem is proven when the graph of dependence between queries to the provers is a tree and, in a bit weaker form, when this graph is a cycle.
PARTITION REFINEMENT TECHNIQUES: AN INTERESTING ALGORITHMIC TOOL KIT
Authors: HABIB MICHEL , PAUL CHRISTOPHE , VIENNOT LAURENT
Published: July 2002

Partition refinement techniques lead to simple and efficient algorithms for various applications: automaton minimization, string sorting … and also for algorithms on graphs. A generic algorithm that can be used for all these applications is presented and briefly discussed. Such an approach is interesting in an algorithmic tool kit perspective. New instances of the generic algorithm are presented: O(n+m log n) very simple and practical algorithms for cographs recognition and for modular decomposition are designed. Although these algorithms are not linear, they are very easy to implement (as an instanciation of a generic procedure) and based on new ideas.
MACDONALD INTEGRALS AND MONODROMY
Authors: DENEF JAN , LOESER FRANÇOIS
Published: July 2002

We prove several results on monodromies associated to Macdonald integrals, that were used in our previous work on the finite field analogue of a conjecture of Macdonald. We also give a new proof of our formula expressing recursively the zeta function of the local monodromy at the origin of the discriminant of a finite Coxeter group in terms of the degrees of the group.
ON THE VARIETY OF SPECIAL LINEAR SYSTEMS OF DEGREE g-1 ON SMOOTH ALGEBRAIC CURVES
Authors: CHO KYUNG-HYE , KEEM CHANGHO , OHBUCHI AKIRA
Published: July 2002

We classify smooth projective algebraic curves C of genus g such that the variety of special linear systems [Formula: see text] has dimension g- 7. We first prove that if [Formula: see text] has dimension g-7≥0 then C is either trigonal, tetragonal, a double covering of a curve of genus 2 or a smooth plane sextic. This result establishes the next extension of dimension theorems of H. Martens and D. Mumford on the variety of special linear systems with the fullest possible generality. We then proceed to show that, under the assumption g≥11, [Formula: see text] has dimension g- 7 if and only if C is either a trigonal curve or a double covering of a curve of genus 2.
AUTOMORPHIC FORMS AND LORENTZIAN KAC–MOODY ALGEBRAS PART I
Authors: GRITSENKO VALERI A. , NIKULIN VIACHESLAV V.
Published: July 2002

Using the general method which was applied to prove finiteness of the set of hyperbolic generalized Cartan matrices of elliptic and parabolic type, we classify all symmetric (and twisted to symmetric) hyperbolic generalized Cartan matrices of elliptic type and of rank 3 with a lattice Weyl vector.

We develop the general theory of reflective lattices T with 2 negative squares and reflective automorphic forms on homogeneous domains of type IV defined by T. We consider this theory as mirror symmetric to the theory of elliptic and parabolic hyperbolic reflection groups and corresponding hyperbolic root systems. We formulate Arithmetic Mirror Symmetry Conjecture relating both these theories and prove some statements to support this Conjecture. This subject is connected with automorphic correction of Lorentzian Kac–Moody algebras. We define Lie reflective automorphic forms which are the most beautiful automorphic forms defining automorphic Lorentzian Kac–Moody algebras and formulate finiteness Conjecture for these forms.

Detailed study of automorphic correction and Lie reflective automorphic forms for generalized Cartan matrices mentioned above will be given in Part II.
AB INITIO ANALYTIC CUBIC FORCE CONSTANT IN GENERAL COORDINATE SPACE USING SPHERICAL GAUSSIAN FUNCTION
Authors: SOLIMANNEJAD M. , PAKIARI A. H.
Published: July 2002

The Floating Spherical Gaussian Orbital (FSGO) closed-shell energy analytic third derivative with respect to nuclear displacement is presented here. In order to save computational time, the formulas for the third derivative of electron nuclear attraction are written in terms of original integrals. Although the formulas were presented in general for any type of application, the FSGO method is applied to H 2 O and CH 2 molecules in singlet ground electronic state. Besides the accuracy of analytical derivative, the saving in computational time is significant.
THE EFFECTS OF NONLOCAL INTERACTIONS IN RARE B DECAYS, B→Xsl+l-
Authors: FUKAE S. , KIM C. S. , YOSHIKAWA T.
Published: July 2002

The effects of nonlocal interactions in rare B decays, B→ Xsl+l-, are investigated. We show the correlation between the branching ratio and the forward–backward asymmetry via two coefficients of the nonlocal interactions. This will certainly help us find any deviations from the standard model through the nonlocal interactions.
GAUGE-INVARIANT FIELDS IN THE TEMPORAL GAUGE, COULOMB-GAUGE FIELDS, AND THE GRIBOV AMBIGUITY
Authors: HALLER KURT
Published: July 2002

We examine the relation between Coulomb-gauge fields and the gauge-invariant fields constructed in the temporal gauge for two-color QCD by comparing a variety of properties, including their equal-time commutation rules and those of their conjugate chromoelectric fields. We also express the temporal-gauge Hamiltonian in terms of gauge-invariant fields and show that it can be interpreted as a sum of the Coulomb-gauge Hamiltonian and another part that is important for determining the equations of motion of temporal-gauge fields, but that can never affect the time evolution of "physical" state vectors. We also discuss multiplicities of gauge-invariant temporal-gauge fields that belong to different topological sectors and that, in a previous work, were shown to be based on the same underlying gauge-dependent temporal-gauge fields. We argue that these multiplicities of gauge-invariant fields are manifestations of the Gribov ambiguity. We show that the differential equation that bases the multiplicities of gauge-invariant fields on their underlying gauge-dependent temporal-gauge fields has nonlinearities identical to those of the "Gribov" equation, which demonstrates the nonuniqueness of Coulomb-gauge fields. These multiplicities of gauge-invariant fields — and, hence, Gribov copies — appear in the temporal gauge, but only with the imposition of Gauss' law and the implementation of gauge invariance; they do not arise when the theory is represented in terms of gauge-dependent fields and Gauss' law is left unimplemented.
QUARK ORBITAL ANGULAR MOMENTUM IN THE BARYON
Authors: SONG XIAOTONG
Published: July 2002

Analytical and numerical results, for the orbital and spin content carried by different quark flavors in the baryons, are given in the chiral quark model with symmetry breaking. The reduction of the quark spin, due to the spin dilution in the chiral splitting processes, is transferred into the orbital motion of quarks and antiquarks. The orbital angular momentum for each quark flavor in the proton as a function of the partition factor κ and the chiral splitting probability a is shown. The cancellation between the spin and orbital contributions in the spin sum rule and in the baryon magnetic moments is discussed.
EVIDENCE FOR TWO NEUTRAL PIONS
Authors: PERKINS W. A.
Published: July 2002

Experimental results from π-, K-, Σ- capture, [Formula: see text] and [Formula: see text] annihilations in liquid H2 show that the fraction of captures and annihilations from atomic P states is less than 5% in agreement with theoretical expectations. However, an anomalously large fraction from P states by a factor of ten is inferred from the branching ratios for the reactions [Formula: see text] and [Formula: see text] at rest in liquid H2 and liquid D2 respectively. One explanation for this inconsistenct is that the reaction [Formula: see text] is occurring from an atomic S state of protnium, which is possible if the two π0's are not identical. It should be noted that a second neutral pion (with different lifetime and decay properties) was observed in antinucleon-nucleon reactions in a 1964 experiment. We describe two experimental tests, one to determine whether [Formula: see text] can occur from an atomic S state, and another to search for the π0π0 decay mode of neutral vector mesons with JPC = 1--.
Atomic Electron Configuration
Authors: Pressler David E.
Published: July 2002

In this work I suggest that early twentieth century theoretical physicists did not have enough facts or experimental data to formulate a consistent atomic model and as a result the concept of the atom needs revised. I conclude that the new atomic model presented is based only on first principles, is easy to understand and visualize, and provides such a significant theoretical advance as to be a final theory.
RECENT RESULTS FROM AMANDA
Authors:   Presented by D. F. Cowen for the AMANDA Collaboration, Andrés E. , Askebjer P. , Bai X. , Barouch G. , Barwick S. W. , Bay R. C. , Becker K.-H. , Bergström L. , Bertrand D. , Bierenbaum D. , Biron A. , Booth J. , Botner O. , Bouchta A. , Boyce M. M. , Carius S. , Chen A. , Chirkin D. , Conrad J. , Cooley J. , Costa C. G. S. , Cowen D. F. , Dailing J. , Dalberg E. , de Young T. , Desiati P. , Dewulf J.-P. , Doksus P. , Edsjö J. , Ekström P. , Erlandsson B. , Feser T. , Gaug M. , Goldschmidt A. , Goobar A. , Gray L. , Haase H. , Hallgren A. , Halzen F. , Hanson K. , Hardtke R. , He Y. D. , Hellwig M. , Heukenkamp H. , Hill G. C. , Hulth P. O. , Hundertmark S. , Jacobsen J. , Kandhadai V. , Karle A. , Kim J. , Koci B. , Köpke L. , Kowalski M. , Leich H. , Leuthold M. , Lindahl P. , Liubarsky I. , Loaiza P. , Lowder D. M. , Ludvig J. , Madsen J. , Marciniewski P. , Matis H. S. , Mihalyi A. , Mikolajski T. , Miller T. C. , Minaeva Y. , Miočinović P. , Mock P. C. , Morse R. , Neunhöffer T. , Newcomer F. M. , Niessen P. , Nygren D. R. , Ogelman H. , Pérez de los Heros C. , Porrata R. , Price P. B. , Rawlins K. , Reed C. , Rhode W. , Richards A. , Richter S. , Rodríguez Martino J. , Romenesko P. , Ross D. , Rubinstein H. , Sander H.-G. , Scheider T. , Schmidt T. , Schneider D. , Schneider E. , Schwarz R. , Silvestri A. , Solarz M. , Spiczak G. M. , Spiering C. , Starinsky N. , Steele D. , Steffen P. , Stokstad R. G. , Streicher O. , Sun Q. , Taboada I. , Thollander L. , Thon T. , Tilav S. , Usechak N. , Vander Donckt M. , Walck C. , Weinheimer C. , Wiebusch C. H. , Wischnewski R. , Wissing H. , Woschnagg K. , Wu W. , Yodh G. , Young S.
Published: July 2002

We present results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope.
(FIELD) SYMMETRIZATION SELECTION RULES
Authors: PAGE PHILIP R.
Published: July 2002

QCD and QED exhibit an infinite set of three-point Green's functions that contain only OZI rule violating contributions, and (for QCD) are subleading in the large N c expansion. We prove that the QCD amplitude for a neutral hybrid 1-+ exotic current to create ηπ0 only comes from OZI rule violation contributions under certain conditions, and is subleading in N c .
HYDRODYNAMICS OF RELATIVISTIC SYSTEMS WITH BROKEN CONTINUOUS SYMMETRIES
Authors: SON D. T.
Published: July 2002

We show how hydrodynamics of relativistic system with broken continuous symmetry can be constructed using the Poisson bracket technique. We illustrate the method on the example of relativistic superfluids.
POWER-SUPPRESSED THERMAL EFFECTS FROM HEAVY PARTICLES
Authors: JIA YU
Published: July 2002

In quantum field theory, heavy particles with mass M much greater than the temperature T give not only effects suppressed by the Boltzmann factor e-M/T, but also effects suppressed by powers of T/M. We show that power-suppressed terms in equilibrium observables arise from effective interactions among light particles due to virtual heavy particles. We study a model introduced by Matsumoto and Yoshimura in which heavy bosons interact only through a term that allows pair annihilation into light particles. We construct an effective Lagrangian for the light field by integrating out the heavy field, and use it to calculate the leading power-suppressed terms in the energy density. The thermal average of the Hamiltonian density for the heavy field includes a term proportional to T6/M2, but we show that this term can be eliminated by a field redefinition and therefore cannot have any physical significance.
GRAVITON ENHANCED UHE NEUTRINO CROSS-SECTIONS AND GIANT AIR SHOWERS
Authors: JAIN AMBAR , JAIN PANKAJ , MCKAY DOUGLAS W. , RALSTON JOHN P.
Published: July 2002

The origin of the highest energy cosmic ray showers is a long standing puzzle. In models where the neutrino–proton cross-section rises to typical hadronic values at energies above 1020 eV, the neutrino becomes a candidate for the primary that initiates these showers. Large extra dimension, low scale gravity models suggest just such a strong neutrino interaction possibility. This raises a further question: are the characteristics of observed showers consistent with a neutrino origin? We simulate neutrino induced showers and compare them to proton-induced showers and to data. The comparison includes the study of starting depth, profile with depth, lateral particle distribution at ground and muon lateral distribution at ground level. Our comparison applies to any model of a strongly interacting, neutral particle with an energy transfer per collision of order 10% similar to the neutrino model studied here. We find that for cross-sections above 20 mb there are regions of parameter space where the two types of showers are nearly indistinguishable. We conclude that the neutrino candidate hypothesis cannot presently be ruled out on the basis of shower characteristics.
LOCAL POLARIZATION, ELECTRON STRIPE, AND HIGH-Tc SUPERCONDUCTIVITY IN LAYERED CUPRATES
Authors: Kuwata S.
Published: July 2002

We examine the possibility of high-Tc superconductivity mediated by the elementary excitation of an electron stripe which is realized by neutralizing local polarization mainly caused by the c-displacement of ions on the CuO 2 plane. Under the translation invariance of the electronic state of the neutralization charges, it is found that both itinerant and localized electrons and/or holes can coexist in the stripe phase. If the frequency of the localized charge oscillation tends to soften along the stripe direction, superconductivity with Tc around 100 K can be realized, due to the enhancement of the coupling constant.
RENORMALIZATION GROUP ANALYSIS OF QUANTUM CRITICAL POINTS IN d-WAVE SUPERCONDUCTORS
Authors: VOJTA MATTHIAS , ZHANG YING , SACHDEV SUBIR
Published: July 2002

We describe a search for renormalization group fixed points which control a second-order quantum phase transition between a dx2-y2-superconductor and some other superconducting ground state. Only a few candidate fixed points are found. In the finite temperature (T) quantum-critical region of some of these fixed points, the fermion quasiparticle lifetime is very short and the spectral function has an energy width of order kBT near the Fermi points. Under the same conditions, the thermal conductivity is infinite in the scaling limit. We thus provide simple, explicit, examples of quantum theories in two dimensions for which a purely fermionic quasiparticle description of transport is badly violated.
COMPUTATION OF ENERGIES IN THE LOWEST LANDAU LEVEL
Authors: BAZZALI D. , TRUONG T. T.
Published: July 2002

We propose a novel calculation scheme to obtain various relevant energies in the Fractional Quantum Hall Effect for Ne charged particles confined to a disk interacting through Coulomb repulsion and with an uniform neutralizing background in the Lowest Landau Level. Numerical values for small Ne are compared to values obtained by Monte Carlo simulations or exact numerical diagonalizations. They are found to be remarkably close to each other, for different filling factors when the Laughlin wave function is used.
QUANTUM HALL TRANSITION IN THE CLASSICAL LIMIT
Authors: GURARIE V. , ZEE A.
Published: July 2002

We study the quantum Hall transition using the density–density correlation function. We show that in the limit ℏ → 0 the electron density moves along the percolating trajectories, undergoing normal diffusion. The localization exponent coincides with its percolation value ν=4/3. The framework provides a natural way to study the renormalization group flow from percolation to quantum Hall transition. We also confirm numerically that the critical conductivity of a classical limit of quantum Hall transition is [Formula: see text].
EFFECT OF OXYGEN DOPING AND HIGH PRESSURE ON THE ELECTRONIC STRUCTURE OF HgBa2CuO4+δ AND SUPERCONDUCTIVITY
Authors: ZHANG SHUANG , HAN QIANG , ZHANG LI-YUAN
Published: July 2002

The effects of oxygen doping (δ=0~0.19) and high pressure (P=0~5.07 GPa) on the electronic structure of HgBa2CuO4+δ have been studied by the recursion method. The hole concentration of the CuO2 layer increases monotonically as δ increases from 0 to 0.19. Each excess oxygen atom contributes about 1.9 holes to the CuO2 layer. The pressure-induced charge transfer, dn/dP, decreases for increasing δ, vanishing at over-doping level, which is consistent with the δ-dependence of dT c /dP observed in experiments.
EXPLORING THE ADIABATIC CONNECTION BETWEEN WEAK- AND STRONG-INTERACTION LIMITS IN DENSITY FUNCTIONAL THEORY
Authors: PERDEW JOHN P. , KURTH STEFAN , SEIDL MICHAEL
Published: July 2002

If the electron-electron repulsion in an atom or molecule were very weak, it could be treated by orbital-based perturbation theory. If this repulsion were very strong, it could be treated in a model of strict correlation. A simple interaction strength interpolation between these two limits, at fixed electron density, can describe the reality that lies between the extremes. By working entirely within a sophisticated density functional approximation, the meta-generalized gradient approximation, we find that the interpolation error is only about 0.1% for the exchange-correlation energy and about 4 kcal/mole = 0.17 eV for the atomization energy. We also find that real systems probably lie close to the radius of convergence of density functional perturbation theory.
TRICONCAVE SOLUTION TO THE HELFRICH VARIATION PROBLEM FOR THE SHAPE OF LIPID BILAYER VESICLES IS FOUND BY "SURFACE EVOLVER"
Authors: ZHANG YONG , ZHOU XIN , ZHOU JIANJUN , OU-YANG ZHONG-CAN
Published: July 2002

We numerically show the existence of triconcave Red Blood Cell (RBC) according to Helfrich spontaneous curvature model. It suggests that the Helfrich spontaneous curvature model can well work in the case of non-axisymmetric vesicle. Some geometric and physical parameters are obtained to describe the triconcave RBC which has been observed in fresh blood under the circumstance of certain hemolytic anemias. Comparing with the normal RBC, we find that the differences between the interior and the exterior of the triconcave RBC are smaller than that of the normal RBC.
CRYSTAL-CHEMICAL STUDY BY XANES OF TRIOCTAHEDRAL MICAS: THE MOST CHARACTERISTIC LAYER SILICATES
Authors: TOMBOLINI F. , MARCELLI A. , MOTTANA A. , CIBIN G. , BRIGATTI M. F. , GIULI G.
Published: July 2002

A crystal-chemical study of trioctahedral micas previously characterized by single-crystal XRD has been performed by XANES spectroscopy at the Si and Al K edges. XANES, being a local structural probe, can investigate distortion and modification of the tetrahedral sheet with increasing Fe for Mg substitution in the octahedral sheet. Comparison of XANES spectra allows determining the size of the tetrahedral site occupied by either Si or Al. The Si-O distance remains essentially unchanged whereas the Al-O distance appears to increase. The behavior may be interpreted as a tilt of the tetrahedra, initially rotated to match the ideal mica geometry, with increasing Fe substitution in the octahedral sheet.
WEIGHTED FIXED POINTS IN SELF-SIMILAR ANALYSIS OF TIME SERIES
Authors: YUKALOV V. I. , GLUZMAN S.
Published: July 2002

The self-similar analysis of time series is generalized by introducing the notion of scenario probabilities. This makes it possible to give a complete statistical description for the forecast spectrum by defining the average forecast as a weighted fixed point and by calculating the corresponding a priori standard deviation and variance coefficient. Several examples of stock-market time series illustrate the method.
COULOMB AND HARD CORE SKYRMION TAILS
Authors: REZAYI E. H. , SONDHI S. L.
Published: July 2002

Quantum Hall skyrmions are quantized solitons of a ferromagnetic O(3) σ-model. The reference, classical, solutions depend upon the interaction between the electrons and exhibit completely different asymptotic profiles for the physical Coulomb interaction than for the hard core interaction frequently used to generate variational wavefunctions. In this note we show, by means of numerical calculations on (large) finite size systems at ν=1, that this physically important difference, crucial for a sharp definition of their statistics, persists for the quantized skyrmions at ν=1.
STUDY OF SELENIUM DOPED Bi-BASED SUPERCONDUCTORS BY AES AND SEM
Authors: SIDDIQI S. A. , ASLAM AFFIA , NASEEM S.
Published: July 2002

Compositions in Bi 2 Sr 2 Ca 2 Cu 3 O y: Se x with x = 0, 0.05, 0.1, 0.2, 0.3, 0.4 have been prepared by the solid state reaction method. The samples have initially been studied by the X-ray powder diffraction method for structural characterization. Superconducting transition temperatures (T c ) measured by the four probe technique shows dependence on selenium concentration. A detailed microstructural analysis has been carried out by scanning electron and Auger electron spectroscopies in order to investigate the incorporation of selenium in the grains of the superconductors. It is found that Se concentration affects both the T c values and the morphology of the grains. AES studies clearly show the presence of selenium in the grains of the superconductor.
Quantum Statistical Mechanics and Thermodynamics of a Multispecies Quasiparticle Gas with Mutual Fractional Exclusion Statistics
Authors: Iguchi Kazumoto
Published: July 2002

Quantum statistical mechanics and thermodynamics of an ideal gas of multispecies quasiparticles with mutual fractional exclusion statistics are discussed. It is shown that thermodynamic potential and density of the system are analytically expressed in terms of the language of generalized cluster expansions, where the cluster coefficients are determined from Wu's functional relations of distribution functions for mutual fractional exclusion statistics.
CAPTURE ON HIGH CURVATURE REGION: AGGREGATION OF COLLOIDAL PARTICLE BOUND TO GIANT PHOSPHOLIPID VESICLES
Authors: LIU QUAN-HUI , LIU JI-XING , OU-YANG ZHONG-CAN
Published: July 2002

A very recent observation on the membrane-mediated attraction and ordered aggregation of colloidal particles bound to giant phospholipid vesicles (I. Koltover, J. O. Rädler and C. R. Safinya, Phys. Rev. Lett.82, 1991 (1999)) is investigated theoretically within the framework of Helfrich curvature elasticity theory of lipid bilayer fluid membrane. Since the concave or waist regions of the vesicle possess the highest local bending energy density, the aggregation of colloidal beads on these places can reduce the elastic energy in maximum. Our calculation shows that a bead in the concave region lowers its energy by ~20 k B T. For an axisymmetrical dumbbell vesicle, the local curvature energy density along the waist is of equal maximum, thus, the beads can be distributed freely with varying separation distance.
UNIFIED TREATMENT OF A+B→0 AND A+A→0 CHEMICAL REACTIONS THROUGH THOMPSON'S APPROACH
Authors: NASSIF CLÁUDIO , SILVA P. R.
Published: July 2002

In this work we propose an action to describe diffusion limited chemical reactions belonging to various classes of universality. This action is treated through Thompson's approach and can encompass both cases where we have segregation as in the A + B →0 reaction, as well as the simplest one, namely the A + A →0 reaction. Our results for long-time and long-wavelength behaviors of the species concentrations and reaction rates agree with exact results of Peliti for A + A →0 reaction and rigorous results of Bramson and Lebowitz for A + B →0 reaction, with equal initial concentrations. The different classes of universality are reflected by the obtained upper critical dimensions varying continuously from d c =2 in the first case to d c =4 in the last one. Just as at the upper critical dimensions, we find universal logarithmic corrections to the mean field behavior.
B-SPLINE BASED STEREO FOR 3D RECONSTRUCTION OF LINE-LIKE OBJECTS USING AFFINE CAMERA MODEL
Authors: XIAO YIJUN , DING MINGYUE , PENG JIAXIONG
Published: July 2002

This paper presents a novel curve based algorithm of stereo vision to reconstruct 3D line-like objects. B-spline approximations of 2D edge curves are selected as primitives for the reconstruction of their corresponding space curves so that, under the assumption of affine camera model, a 3D curve can be derived from reconstructing its control points according to the affine invariant property of B-Spline curves. The superiority of B-spline model in representing free-form curves gives good geometric properties of reconstruction results. Both theoretical analysis and experimental results demonstrate the validity of our approach.
GENERALIZED SYNCHRONIZATION OF CHAOS VIA LINEAR TRANSFORMATIONS
Authors: YANG TAO , CHUA LEON O.
Published: July 2002

Generalized synchronization (GS) of two chaotic systems is a generalization of identical synchronization. Usually, the manifold of GS is much more complex than the driven system and the driving system. In this paper, we study a special case of GS in which the synchronization manifold is linear (linear GS for short). In a theorem, we present the necessary and sufficient conditions under which a linear GS can be achieved between two chaotic systems. In particular, we study the linear GS of two Chua's circuits.
DYNAMICS OF MULTIBODY SYSTEMS WITH UNILATERAL CONSTRAINTS
Authors: WÖSLE M. , PFEIFFER F.
Published: July 2002

In couplings of machines and mechanisms, backlash and friction phenomena are always occurring. Whether stick–slip phenomena take place depends on the structure of such couplings. These processes can be modeled as multibody systems with a time-varying topology. Making use of Lagrange multiplier methods with a mathematical formulation of the contact problem is very efficient for large systems with many constraints. In the following, the differential-algebraic equations are transformed into a resolvable mathematical form by means of the contact laws in equation form. Ultimately we get a nonlinear system of equations for the three-dimensional contact problem with dependent constraints. For its solution, the homotopy method will be used and applied to a simple mechanical system.
SOME RESULTS ON ENTROPY AND SEQUENCE ENTROPY
Authors: BALIBREA F. , LÓPEZ V. JIMÉNEZ , PEÑA J. S. CÁNOVAS
Published: July 2002

In this paper we study some formulas involving metric and topological entropy and sequence entropy. We summarize some classical formulas satisfied by metric and topological entropy and ask the question whether the same or similar results hold for sequence entropy. In general the answer is negative; still some questions involving these formulas remain open. We make a special emphasis on the commutativity formula for topological entropy h(f ◦ g)=h(g ◦ f) recently proved by Kolyada and Snoha. We give a new elementary proof and use similar ideas to prove commutativity formulas for metric entropy and other topological invariants. Finally we prove a Misiurewicz–Szlenk type inequality for topological sequence entropy for piecewise monotone maps on the interval I=[0, 1]. For this purpose we introduce the notion of upper entropy.
PERIODIC MOTIONS AND NONLINEAR DYNAMICS OF A WHEELSET MODEL
Authors: FRANKE CORNELIA
Published: July 2002

Periodic motions and nonlinear dynamics of a wheelset model are investigated numerically. The equations of motion of this multibody system belong to a special class of differential-algebraic equations (DAEs). In contrast to previous investigations of wheelset models the equations are treated directly as DAEs and are not reduced by simplifications to an explicit ODE. Further, it is shown how basic tools for the analysis of Hopf bifurcations and stability of periodic solutions can be transferred to this class of DAEs.