bluuebunny/crossref_metadata_2025 huggingface dataset:
Cancer in veterinarians
Authors: Fritschi Lin
Published: July 2002

OBJECTIVES

Veterinarians come into contact with several potentially carcinogenic exposures in the course of their occupation. These exposures include radiation, anaesthetic gases, pesticides (particularly insecticides), and zoonotic organisms. This review aims to summarise what is known about the carcinogenic risks in this profession.

METHODS

The levels of exposure to potential carcinogens in the veterinary profession are examined and evidence is reviewed for carcinogenesis of these substances in humans at doses similar to those experienced by veterinarians. The few published studies of cancer in veterinarians are also summarised.

RESULTS

Veterinarians have considerable potential for exposure to several known and potential carcinogens. Risks may be posed by work in clinics with poorly maintainedxray equipment, by use of insecticides, and from contact with carcinogenic zoonotic organisms. The few studies available suggest that veterinarians have increased mortality from lymphohaematopoietic cancers, melanoma, and possibly colon cancer.

CONCLUSIONS

The exposures examined in this review are not unique to the veterinary profession, and, as a consequence, information gathered on the carcinogenic risks of these exposures has implications for many other occupations such as veterinary nurses, animal handlers, and some farmers, as well as dentists, radiographers, and anaesthetists.
Update of a study of crude oil production workers 1946–94
Authors: Divine Barbara J , Hartman Christine M
Published: July 2002

OBJECTIVE

To update information on workers in the petroleum industry engaged in the production of crude oil to determine whether the patterns of mortality have changed with 14 additional years of follow up.

METHODS

All workers were employed at company production and pipeline locations sometime during 1946–94. The cohort now consists of 24 124 employees with an average of 22 years of follow up.

RESULTS

The overall mortality, and most cause specific mortalities were lower than or similar to those for the general United States population. For white men (81% of the cohort), there were 4361 observed deaths and 5945 expected, resulting in a significantly lower standardised mortality ratio (SMR) of 73. There were significant deficits for all the leading causes of death in the United States including all cancers, cancer of the lung, stroke, heart disease, respiratory disease, and accidents. Slightly increased mortality was found for cancer of the prostate, cancer of the brain and central nervous system, and cancer of other lymphatic tissue. For benign and unspecified neoplasms, the SMR was 152 (95% confidence interval (95% CI) 95 to 230). There was a significant increase for acute myelogenous leukaemia that was restricted to people who were first employed before 1940 and who were employed in production and pipeline jobs for >30 years. Overall mortality patterns for non-white men and women were similar to those for white men. Mortality patterns for white men were also examined by duration of employment, time first employed, and by job group.

CONCLUSIONS

The results of the updated study showed a favourable mortality experience for crude oil production workers compared with the United States population.
Development of an asthma specific job exposure matrix and its application in the epidemiological study of genetics and environment in asthma (EGEA)
Authors: Kennedy Susan M , Le Moual Nicole , Choudat Dominique , Kauffmann Francine
Published: July 2002

OBJECTIVES

To develop a method suitable for estimating exposure risks in population studies of asthma from job titles and international codes, by combining a new job exposure matrix (JEM) with the expert judgement approach. The method was applied in the French epidemiological study of the genetics and environment in asthma (EGEA).

METHODS

The JEM contains 22 exposure groups including 18 high risk groups based on known risk factors for occupational asthma, divided into high molecular weight agents, low molecular weight agents, and mixed environments. After applying the JEM to job codes, exposure estimates for each subject were re-evaluated by examining job title texts. Three high risk exposure estimates for asthma were compared: firstly, applying the JEM to original codes (from different coders in each study centre); secondly, applying the JEM to revised codes (from one experienced coder); and thirdly, after reviewing JEM exposure estimates in the light of job title texts.

RESULTS

The study comprised 173 cases with asthma and 285 controls (age 18–65). Odds ratios (ORs) for asthma for high risk jobs were 1.0 (95% confidence interval (95% CI) 0.6 to 1.7), applying the JEM to original codes; 1.4 (95% CI 0.8 to 2.3), applying the JEM to revised codes; and 1.7 (95% CI 1.1 to 2.7), applying the JEM and subsequently re-evaluating exposure estimates from job title texts. Asthma ORs were 1.4 (95% CI 0.6 to 2.9) for high molecular weight agents, 2.3 (95% CI 1.2 to 4.4) for low molecular weight agents, and 2.1 (95% CI 0.9 to 5.2) for mixed environments.

CONCLUSIONS

This asthma JEM, when enhanced by expert re-evaluation of exposure estimates from job title texts, may be a useful tool in general population studies of asthma. In this study, a 1.7-fold increase in prevalence odds of high risk exposures was found among asthmatic workers compared with controls, with risk magnitude varying for different classes of exposure.
The role of extended weekends in sickness absenteeism
Authors: Vahtera J , Kivimäki M , Pentti J
Published: July 2002

OBJECTIVES

Employees are thought to lengthen their weekends by voluntary absenteeism, but the magnitude of such potentially reversible behaviour is not known.

METHODS

A follow up study based on employers' registers on the dates of work contracts and absences in 27 541 permanent full time municipal employees in five towns during 1993–7. The absence rate on each weekday separately for all sick leaves and for 1 day sick leaves was determined.

RESULTS

3.4% of the male employees and 5.0% of the female employees were on sick leave daily. The mean rate of sickness absence was lowest on Mondays, after which it increased towards Wednesday, and remained on the same level for the rest of the week. This pattern applied to both sexes, to each year of the follow up, and across towns, age groups, and income groups. For 1 day sick leaves, representing 4.5% of the total sickness absenteeism, the rates of sick leave for Mondays and Fridays were 1.4 and 1.9 times greater than those for other weekdays. However, these excess rates account for less than 1% of all days lost due to sickness absenteeism. Extended weekend absences were more common in men, in young employees, and in those in a low socioeconomic position, and they varied between towns.

CONCLUSION

Extended weekends seem to contribute only marginally to the days lost due to sickness absenteeism.
Longitudinal study on work related and individual risk factors affecting radiating neck pain
Authors: Viikari-Juntura E , Martikainen R , Luukkonen R , Mutanen P , Takala E-P , Riihimäki H
Published: July 2002

OBJECTIVES

To study the effects of work related and individual factors affecting radiating neck pain.

METHODS

A longitudinal study was carried out with repeated measurements. A total of 5180 Finnish forest industry workers replied to a questionnaire survey in 1992 (response rate 75%). Response rates to follow up questionnaires in 1993, 1994, and 1995 were 83%, 77%, and 90%, respectively. The outcome variable was the number of days with radiating neck pain during the preceding 12 months with three levels (<8, 8–30, >30 days). The generalised estimating equations method was used to fit a marginal model and a transition model was used in a predictive analysis.

RESULTS

Items showing associations with radiating neck pain in both analyses were sex, age, body mass index, smoking, duration of work with a hand above shoulder level, mental stress, and other musculoskeletal pains. In the transition model, radiating neck pain in a previous questionnaire was included in the model. Although it was a strong predictor, the variables already mentioned retained their significance.

CONCLUSION

Programmes targeted to reduce physical load at work, mental stress, being overweight, and smoking could potentially prevent radiating neck pain.
Primary haematogenous osteomyelitis of the patella: a rare cause for anterior knee pain in an adult
Authors: Kankate R K , Selvan T P
Published: July 2002

Acute osteomyelitis of the patella is a very rare condition, which commonly affects children between the ages of 5–15 years. Primary haematogenous osteomyelitis in an adult usually occurs in patients with associated risk factors like intravenous drug abuse, HIV infection, and trauma. This report discusses a similar condition in a 46 year old women with no associated predisposing risk factors. The rarity of this condition and its atypical presentation should be borne in mind while treating an adult patient with anterior knee pain. Point tenderness over the patella should alert a physician to the possibility of osteomyelitis of the patella. The value of bone scan and computed tomography in the early stages to help diagnose this condition has been stressed. The literature has been reviewed and discussed briefly.
Churg-Strauss syndrome associated with montelukast
Authors: Mukhopadhyay A , Stanley N N
Published: July 2002

Churg-Strauss syndrome (CSS) has recently been reported in patients with asthma receiving leukotriene receptor antagonists (LTRAs). In this paper a case of CSS after treatment with montelukast is described. As in other LTRA treated cases, prior withdrawal of maintenance oral steroid may have unmasked a previously occult CSS in the patient, but a dramatic improvement in his eosinophilia after withdrawing montelukast implied that the drug also had a direct effect in activating this condition.
Changes in the corrected QT interval and corrected QT dispersion during haemodialysis
Authors: Howse M , Sastry S , Bell G M
Published: July 2002

The link between increased QT dispersion and cardiac death in subjects with diabetes and arterial disease is well recognised. Corrected QT dispersion was studied in subjects with end stage renal failure on haemodialysis. Thirty one stable, chronic subjects on haemodialysis had 12-lead electrocardiograms (ECGs) taken before and after a single haemodialysis session. The QT interval was measured manually in each and the corrected QT and corrected QT dispersion calculated. Serum concentrations of potassium, calcium, and magnesium were measured at the same time as ECG acquisition. Corrected QT dispersion increased from a mean (SEM) 90.6 (5.8) to 117.7 (10.2) ms (p=0.002). Serum potassium and magnesium decreased from 5.0 (0.14) to 3.5 (0.09) mmol/l and 0.95 (0.04) to 0.89 (0.09) mmol/l respectively, while serum calcium increased from 2.56 (0.04) to 2.77 (0.04) mmol/l. Intradialytic weight fell by a mean of 2.1 kg. There was no significant correlation between the change in QTc dispersion and the changes in measured serum anions or the subjects’ weight during dialysis. Corrected QT dispersion was higher in subjects on haemodialysis than previously suggested normal values, and was significantly increased by haemodialysis. This reflects increased inhomogeneous ventricular repolarisation, which may lead to an increased risk of arrhythmias and sudden death. Studies looking at QT dispersion in subjects on dialysis should standardise the timing of ECG recordings taken with respect to dialysis.
Older people and ill fitting shoes
Authors: Burns S L , Leese G P , McMurdo M E T
Published: July 2002

Background

Foot health is an important issue in older people. Inappropriate shoes increase the risk of callous and ulcer formation, as well as increasing the risk of falls. There are no data defining the size of this problem.

Objective

The aim of the study was to investigate the proportion of elderly people on a general rehabilitation ward wearing incorrectly sized shoes and to look for the presence of complications.

Methods

Sixty five consecutive patients (mental state questionnaire score >6) admitted to a rehabilitation ward had their foot length and width measured, and the size of their current footwear recorded. Sensation was tested with a standard 10 g monofilament. The presence of ulceration was noted. Foot pain was recorded by the patient on a visual analogue scale. Any history of diabetes mellitus, peripheral vascular disease, or peripheral neuropathy was noted.

Results

The median age of the subjects was 82 (range 64–93). Six (9%) had a history of diabetes, seven (11%) had symptomatic peripheral vascular disease, and 17 (26%) had sensory impairment. Ten patients (15%) had foot ulceration present, and 47 patients (72%) had ill fitting shoes (a discrepancy in length of more than half a British shoe size fitting or more than one British width fitting, 7 mm).

Incorrect shoe length was significantly associated with the presence of ulceration (odds ratio (OR) = 10.04, p = 0.016). Presence of ulceration was significantly associated with a history of peripheral vascular disease (OR = 11.56, p = 0.008). Pain was significantly associated with incorrect shoe length (p = 0.0238) and with sensory impairment (p = 0.0314).

Conclusion

Most older people on a rehabilitation ward wore ill fitting shoes. An association was found between ill fitting shoes and self reported pain, and between ill fitting shoes and ulcer formation.

A straightforward assessment of footwear in older people could improve comfort and avoid preventable foot disorders.
A prescription for health: a primary care based intervention to maintain the non-smoking status of young people
Authors: Fidler Wendy , Lambert Trevor W
Published: July 2002

OBJECTIVES

To evaluate the effectiveness of primary health care teams in maintaining a group of young people aged 10–15 years as non-smokers.

DESIGN

Randomised controlled trial using postal questionnaires.

SETTING

Oxfordshire, UK.

SUBJECTS

2942 young people who were initially self declared non-smokers.

INTERVENTION

Information about smoking, sent under signature of the subject's general practitioner, certificates and posters intended to reinforce non-smoking behaviour.

MAIN OUTCOME MEASURES

Changes in smoking behaviour, attitudes measured after one year.

RESULTS

After a year, smoking uptake was 7.8% in the control group compared with 5.1% in the intervention group (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.1 to 2.2). Among boys the corresponding results were 5.2% and 2.4% (OR 2.3, 95% CI 1.2 to 4.6), and among girls 10.0% and 7.5% (OR 1.4, 95% CI 0.9 to 2.1). Among boys aged 14–15 the uptake rate was 12.8% in the control group compared with 5.4% in the intervention group. However, among girls of the same age the intervention was less effective, with smoking uptake of 15.1% in the control group and 12.8% in the intervention group. The intervention was more effective among young people whose initial attitudes identified them as definite non-smokers than those who were potential smokers.

CONCLUSIONS

The intervention substantially reduced smoking uptake among the young people, particularly boys. Primary health care teams can play an important role in maintaining the non-smoking status of their young patients. Confidential postal contact from the doctor direct to the young person at home is influential and cost-effective.
Responses to tobacco control policies among youth
Authors: Crawford M A , Balch G I , Mermelstein R ,   The Tobacco Control Network Writing Group
Published: July 2002

Objective: Explore adolescents' response to current and potential tobacco control policy issues.

Design: The 13 site Tobacco Control Network (TCN), sponsored by the Centers for Disease Control and Prevention, conducted 129 sex and ethnic homogeneous focus groups.

Participants: 785 white, African American, Asian American/Pacific Islander, American Indian, and Hispanic adolescents who were primarily smokers from rural, urban, and suburban locations across the USA.

Main outcome measures: Awareness, knowledge, opinions, and behaviour regarding laws and rules, prices, cigarette ingredients, and warning labels.

Results: Teenagers were generally familiar with laws and rules about access and possession for minors, but believed them ineffective. They were knowledgeable about prices, and reported that a sharp and sudden increase could lead them to adjust their smoking patterns but could also have negative consequences. They found a list of chemical names of cigarette ingredients largely meaningless, but believed that disclosing and publicising their common uses could be an effective deterrent, especially for those who were not yet smoking. They were aware of current warning labels, but considered them uninformative and irrelevant.

Conclusions: Understanding teenagers' attitudes and behaviours before implementing policies that will affect them will likely increase their effectiveness. Disclosing and publicising the chemical contents of cigarettes, and increasing prices quickly and sharply, are potentially effective areas for policy change to impact adolescent tobacco use.
Planning to become a mom?
Authors: Prins T J J , Honing C
Published: July 2002

The prevalence of smoking among Dutch women is one of the highest in the European Union, with lung cancer and chronic obstructive pulmonary disease frequently the cause of death.
Water status influences common events of soluble carbohydrate accumulation during soybean seed development and germination
Authors: Modi Albert T , McDonald Miller B , Streeter John G
Published: July 2002

Seed development and germination are two distinct physiological stages that are normally separated by a metabolically quiescent period in orthodox seeds. Comparison of seed water status during these two processes and how it influences the biochemical activities remains unclear. The objective of this study was to compare soybean (Glycine max (L.) Merrill cv. Ohio FG1) seed development and germination, including the first 6 h after radicle protrusion, with respect to soluble carbohydrate occurrence at different stages characterized by water content and osmolality. Cyclitols and sugars were monitored at nine stages of development and during the first 30 h of germination. Three phases of water loss and osmolality increase found during seed development were correlated with three phases of water absorption and osmolality decrease during seed germination. This study provided evidence that soybean seed cotyledons and axes have similar patterns of water content and osmolality during seed development and germination and that three major events of soluble carbohydrate occurrence are shared by soybean seed parts during development and germination.Key words: seed development, seed germination, soluble carbohydrates, soybean, water status.
The effect of light availability and basal area on cone production in Abies balsamea and Picea glauca
Authors: Greene David F , Messier Christian , Asselin Hugo , Fortin Marie-Josée
Published: July 2002

Mean annual seed production is assumed to be proportional to basal area for canopy trees, but it is not known if subcanopy trees produce fewer seeds than expected (given their size) because of low light availability. Ovulate cone production was examined for balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) in 1998 and for balsam fir in 2000 in western Quebec using subcanopy stems, near or far from forest edges, or (at one site) planted white spruce trees in fully open conditions. A very simple light model for transmission through mature trembling aspen (Populus tremuloides Michx.) crowns and through boles near forest edges was developed to account for the effect of light receipt on cone production. The enhanced light near forest edges (e.g., recent clearcuts) leads to about a doubling of cone production for subcanopy stems. The minimum subcanopy height for cone production far from an edge is about 10 m for balsam fir and 14 m for white spruce, with these minima decreasing near edges. By contrast, the minimum height for white spruce in a plantation (full light) is about 3 m. Accounting for light receipt leads to an increase in the explained variance.Key words: balsam fir, cone production, light model, regressions, subcanopy stems, white spruce.
Estimation of short-term centers of activity from an array of omnidirectional hydrophones and its use in studying animal movements
Authors: Simpfendorfer Colin A , Heupel Michelle R , Hueter Robert E
Published: July 2002

A method for studying animal movements based on data from independent data-logging acoustic receivers is described. The method takes presence or absence data from multiple receivers arranged in an array and converts them to position estimates based on weighted means of the number of signal receptions at each receiver during a specified time period. The method is equivalent to a short-term center of activity rather than a precise estimate of location at a single time. The utility of the method was assessed using data from a study of neonate blacktip sharks (Carcharhinus limbatus). Periods between 5 and 60 min were tested to find the most appropriate interval for estimating positions. The results from the method agreed closely with a simulated shark track and data from actively tracked sharks. The median distances between successive locations from the mean-position algorithm were between 28% and 42% of those from active tracking because of the center-of-activity nature of the method. The results presented demonstrate that the technique provides a useful method for investigating long-term movement patterns, space utilization patterns over broader areas, and home range.
Cytogenetic and molecular characterization of intergeneric hybrids betweenBrassica napusandOrychophragmus violaceus
Authors: Cheng B F , Séguin-Swartz G , Somers D J
Published: July 2002

Twenty-two intergeneric hybrids from a cross between Brassica napus (AACC, 2n = 38) cultivar Oro and the ornamental crucifer Orychophragmus violaceus (OO, 2n = 24) were produced without embryo rescue. The plants were classified into three groups based on morphological and cytological observations and RAPD banding patterns. Plants of Group I had morphological traits of both parents and 2n = 29 chromosomes. In these plants, 62.1% of the pollen mother cells (PMCs) had the pairing configuration 1 III + 9 II + 8 I; the remaining PMCs had 10 II + 9 I. The plants possessed 97.698.8% B. napus specific and 9.211.7% O. violaceus specific RAPD fragments. Plants of Group II exhibited novel morphological traits and possessed 2n = 35, 36, or 37 chromosomes. Plants of Group III were morphologically similar to B. napus and possessed 2n = 19, 37, 38, or 39 chromosomes. Plants of Group II and Group III had 94.199.4% B. napus specific RAPD fragments and no O. violaceus specific RAPD fragments. Chromosome fragments were observed in PMCs of most of the F1plants in all groups. Based on the cytological results and RAPD analysis, it is suggested that genome doubling and chromosome elimination occurred in the intergeneric hybrids of B. napus × O. violaceus.Key words: Brassica, intergeneric hybridization, meiosis, RAPD, chromosome elimination.
Genetic and physical mapping ofLrk10-like receptor kinase sequences in hexaploid oat (Avena sativaL.)
Authors: Cheng Davis W , Armstrong Ken C , Tinker Nick , Wight Charlene P , He Shan , Lybaert Anissa , Fedak George , Molnar Stephen J
Published: July 2002

Oat receptor-like kinase gene sequences, homologous to the Lrk10 gene from wheat (Triticum aestivum L.), were mapped in oat (Avena sativa L.). PCR primers designed from the wheat Lrk10 were used to produce ALrk10 from oat. Two DNA sequences, ALrk1A1 and ALrk4A5, were produced from primers designed from coding and non-coding regions of ALrk10. Their use as RFLP probes indicated that the kinase genes mapped to four loci on different hexaploid oat 'Kanota' × 'Ogle' linkage groups (4_12, 5, 6, and 13) and to a fifth locus unlinked to other markers. Three of these linkage groups contain a region homologous to the short arm of chromosome 1 of wheat and the fourth contains a region homologous to chromosome 3 of wheat. Analysis with several nullisomics of oat indicated that two of the map locations are on satellite chromosomes. RFLP mapping in a 'Dumont' × 'OT328' population indicated that one map location is closely linked to Pg9, a resistance gene to oat stem rust (Puccinia graminis subsp. avenae). Comparative mapping indicates this to be the region of a presumed cluster of crown rust (Puccinia coronata subsp. avenae) and stem rust resistance genes (Pg3, Pg9, Pc44, Pc46, Pc50, Pc68, Pc95, and PcX). The map position of several RGAs located on KO6 and KO3_38 with respect to Lrk10 and storage protein genes are also reported.Key words: oat, rust resistance genes, molecular markers, comparative mapping, chromosomal location.
Effects of dead loads on the lateral response of battered pile groups
Authors: Zhang L M , McVay M C , Han S J , Lai P W , Gardner R
Published: July 2002

The effects of vertical load on the lateral resistance of single piles were initially reviewed to facilitate the interpretation of the test results of pile groups. Then, 18 different lateral load tests were carried out in the centrifuge on the 3 × 3 and the 4 × 4 fixed-head battered pile groups to investigate the effects of vertical load on the group lateral resistance. Vertical dead loads ranging from approximately 20 to 80% of the vertical ultimate group capacity Puv were applied. Based on these tests, the effects of vertical dead load on the lateral resistance of the battered pile groups are found to depend on pile arrangement, pile inclination, and soil density. The lateral resistances of the 3 × 3 pile groups do not appear to vary considerably with the vertical dead loads in the range of the vertical loads studied. For the 4 × 4 pile groups however, the lateral resistances at vertical loads of approximately 50 and 80% Puv may be 26-29% and even 40% higher than that at the 20% Puv dead load. It may be inferred that designs based on standard lateral load tests with small vertical dead loads would be on the safe side. Three mechanisms for vertical load effects are discussed in terms of axial tension and compression failures, influence of pile inclination, and initial subgrade reaction caused by vertical loading. Preliminary numerical analyses are also performed to simulate the responses of some of the battered pile groups.Key words: pile group, battered pile, lateral resistance, load test, pile-soil interaction, centrifuge test.
Synthesis of new fluorophores derived from monoazacrown ethers and coumarin nucleus
Authors: Brunet Ernesto , García-Losada Pablo , Rodríguez-Ubis Juan-Carlos , Juanes Olga
Published: July 2002

New ionophores derived from azacrown ethers attached to coumarins have been synthesized and characterized. The alkaline-earth complexes of these new ligands were studied from their UVvis, NMR, and fluorescence data. Some systems displayed bathochromic shifts and fluorescence decreases upon complexation with Ca2+ that may make them useful signaling devices of this metal.Key words: alkaline earth, emission, molecular modeling.
Long-term effects of a forest amelioration experiment
Authors: Jandl R , Starlinger F , Englisch M , Herzberger E , Johann E
Published: July 2002

We evaluated the soil chemistry, plant species composition, and forest growth rate on a site where a site amelioration project had been realized 30 years earlier. The initial goal of the project was the improvement of a site that had been degraded by litter raking. We wanted to know which amelioration method produced a sustainable result and how different treatments might be rated by today's standards. Treatments included fertilization, underplanting with N-fixing plants, and a combination of both. The amelioration was combined with stand conversion by means of natural regeneration and spruce underplanting. In all treatments, a spruce-dominated stand replaced the secondary pine stand. The biomass of the formerly recalcitrant forest floor (143 Mg·ha1) was reduced by 30 to 50% in treated plots, thereby reducing the total soil pool of C, N, and exchangeable cations. The mineral soil of treated plots was enriched with N, Ca, and Mg. An increase in pH was restricted to the forest floor. The C pool of treated soils was much smaller than that of the control plots. However, the loss from the soil was at least partly offset by increased growth rates of the aboveground tree biomass. In treated plots, the stem volume was more than twice that of control plots (38.3 m3). Soil chemical data and the composition of the ground vegetation suggest that even the control plots have changed compared with pre-treatment conditions. Comparison of different blocks of the experiment suggests that the exclusion of roe deer (Capreolus capreolus) by fencing was the most significant treatment required for successful stand conversion. Prior to fencing, deer browsing inhibited the establishment of a new stand.
A GRAPH BASED DAVIDSON ALGORITHM FOR THE GRAPH PARTITIONING PROBLEM
Authors: HOLZRICHTER MICHAEL , OLIVEIRA SUELY
Published: July 2002

The problem of partitioning a graph such that the number of edges incident to vertices in different partitions is minimized, arises in many contexts. Some examples include its recursive application for minimizing fill-in in matrix factorizations and load-balancing for parallel algorithms. Spectral graph partitioning algorithms partition a graph using the eigenvector associated with the second smallest eigenvalue of a matrix called the graph Laplacian. The focus of this paper is the use graph theory to compute this eigenvector more quickly.
TIME-DEPENDENT SCATTERING THEORY OF N-BODY QUANTUM SYSTEMS
Authors: HUNZIKER W. , SIGAL I. M.
Published: July 2002

We give a full and self contained account of the basic results in N-body scattering theory which emerged over the last ten years: The existence and completeness of scattering states for potentials decreasing like r-μ, [Formula: see text]. Our approach is a synthesis of earlier work and of new ideas. Global conditions on the potentials are imposed only to define the dynamics. Asymptotic completeness is derived from the fact that the mean square diameter of the system diverges like t2 as t → ±∞ for any orbit ψt which is separated in energy from thresholds and eigenvalues (a generalized version of Mourre's theorem involving only the tails of the potentials at large distances). We introduce new propagation observables which considerably simplify the phase–space analysis. As a topic of general interest we describe a method of commutator expansions.
EDGE CURRENT CHANNELS AND CHERN NUMBERS IN THE INTEGER QUANTUM HALL EFFECT
Authors: KELLENDONK J. , RICHTER T. , SCHULZ-BALDES H.
Published: July 2002

A quantization theorem for the edge currents is proven for discrete magnetic half-plane operators. Hence the edge channel number is a valid concept also in presence of a disordered potential. Under a gap condition on the corresponding planar model, this quantum number is shown to be equal to the quantized Hall conductivity as given by the Kubo–Chern formula. For the proof of this equality, we consider an exact sequence of C*-algebras (the Toeplitz extension) linking the half-plane and the planar problem, and use a duality theorem for the pairings of K-groups with cyclic cohomology.
SOLITON EIGENFUNCTION EQUATIONS: THE IST INTEGRABILITY AND SOME PROPERTIES
Authors: KONOPELCHENKO B.G.
Published: July 2002

Eigenfunctions of the linear eigenvalue problems for the soliton equations obey nonlinear differential equations. It is shown that these eigenfunction equations are integrable by the inverse spectral transform (IST) method. They have triad operator representations. Eigenfunction equations are the generating equations and possess other interesting properties. Eigenfunction equations form a new wide class of nonlinear integrable equations. Eigenfunction equations for several typical, well-known (1+1)-, (2+1)- and multi-dimensional soliton equations are considered. A general method for constructing the auxiliary linear systems for the eigenfunction equations is proposed. It is shown that the vertical hierarchies of the eigenfunction equations contain only finite numbers of different members in the cases considered. The properties of such hierarchies for soliton equations are closely connected with their Painleve properties. Some “linear” properties of the eigenfunction equations are also discussed.
ON THE BIHAMILTONIAN INTERPRETATION OF THE LAX FORMALISM
Authors: MOROSI CARLO , PIZZOCCHERO LIVIO
Published: July 2002

We propose a general framework for constructing systematically the Lax formulation of the soliton equations using the bi-Hamiltonian formalism. The method is applied to several examples, both classical and supersymmetric.
PLANCK-SCALE RELATIVITY FROM QUANTUM κ-POINCARÉ ALGEBRA
Authors: KOWALSKI-GLIKMAN J.
Published: July 2002

Extending the commutator algebra of quantum κ-Poincaré symmetry to the whole of the phase space, and assuming that this algebra is to be covariant under action of deformed Lorentz generators, we derive the transformation properties of positions under the action of deformed boosts. It turns out that these transformations leave invariant the quadratic form in the position space, which is the Minkowski metric and that the boosts saturate. The issues of massless and massive particles motion as well as time dilatation and length contraction in this new framework are also studied.
GENERALIZED STRONG CURVATURE SINGULARITIES AND COSMIC CENSORSHIP
Authors: RUDNICKI WIESŁAW , BUDZYŃSKI ROBERT J. , KONDRACKI WITOLD
Published: July 2002

A new definition of a strong curvature singularity is proposed. This definition is motivated by the definitions given by Tipler and Królak, but is significantly different and more general. All causal geodesics terminating at these new singularities, which we call generalized strong curvature singularities, are classified into three possible types; the classification is based on certain relations between the causal structure and the curvature strength of the singularities. A cosmic censorship theorem is formulated and proved which shows that only one class of generalized strong curvature singularities, corresponding to a single type of geodesics according to our classification, can be naked. Implications of this result for the cosmic censorship hypothesis are indicated.
APPLICATION OF FINITE FIELD-DEPENDENT BRS TRANSFORMATIONS TO PROBLEMS OF THE COULOMB GAUGE
Authors: JOGLEKAR SATISH D. , MANDAL BHABANI PRASAD
Published: July 2002

We discuss the Coulomb propagator in the formalism developed recently in which we construct the Coulomb gauge path-integral by correlating it with the well-defined Lorentz gauge path-integrals through a finite field-dependent BRS transformation. We discover several features of the Coulomb gauge from it. We find that the singular Coulomb gauge has to be treated as the gauge parameter λ → 0 limit. We further find that the propagator so obtained has good high energy behavior[Formula: see text] for λ ≠ 0 and ∊ ≠ 0. We also find that the behavior of the propagator so obtained is sensitive to the order of limits k0→ ∞, λ → 0 and ∊ → 0; so that these have to be handled carefully in a higher loop calculation. We show that we can arrive at the result of Cheng and Tsai for the ambiguous two-loop Feynman integrals without the need for an extra ad hoc regularization and within the path integral formulation.
THE BOND LENGTH DEFORMATION AND THE ELASTIC STRUCTURE IN ICOSAHEDRAL CLUSTERS
Authors: DING FENG , LI HUI , WANG JINLAN , SHEN WEIFENG , WANG GUANGHOU
Published: July 2002

In this paper, a theory about the elastic deformation in icosahedral clusters was proposed. We have obtained the analytical expression of the elastic deformation distribution in icosahedral clusters, which is in good agreement with the results of numerical simulation. Both our theory and the results of numerical simulation indicate that the icosahedral clusters are not uniformly deformed, the bond length increases moving from center to surface.
KEY CONCEPTS IN TIME-DEPENDENT DENSITY-FUNCTIONAL THEORY
Authors: VAN LEEUWEN ROBERT
Published: July 2002

We give an overview of the underlying concepts of time-dependent density-functional theory. The basic relations between densities, potentials and initial states, for time-dependent many-body systems are discussed. We obtain some new results concerning the invertability of response functions. Some fundamental difficulties associated with the time-dependent action principle are discussed and we show how these difficulties can be resolved by means of the Keldysh formalism.
EFFECT OF ADSORBATE-ADSORBATE INTERACTIONS ON LOW TEMPERATURE SURFACE ADSORPTION PATTERNS
Authors: PHARES ALAIN J. , WUNDERLICH FRANCIS J.
Published: July 2002

Low temperature surface adsorption at thermodynamic equilibrium is studied using a lattice model. So far, we have investigated fcc (100) and bcc (110) surfaces, with a finite number M of sites in one direction, and an infinite number of sites in the other, and no periodic boundaries. Here, we consider fcc (110) surfaces with first- (V), second- (W) and third- (U) neighbor adsorbate-adsorbate interaction energies, considered as arbitrary parameters. Adsorption is assumed to be on-site, or at locations commensurate with the substrate. Thus adsorbates are treated as monomers. A monomer in the gas phase has a chemical potential μ′ that depends on the gas pressure. With V 0 representing the lattice-adsorbate interaction energy, then μ′ and V 0 appear as the combination μ =μ′ + V 0. While keeping the temperature sufficiently low, the gas pressure is gradually increased, accompanied by an increase of μ. The surface begins to fill and phases with increasing coverage are observed until the surface is fully covered. The patterns depend both on the substrate and the adsorbates, and consequently on the interaction energies. A phase is characterized by the coverage θ0, and the numbers per site, θ, β and γ of first- second- and third-neighbor adsorbate-adsorbate, respectively. The occupational characteristics of the phases and most of the transitions between phases are found to fit exact analytic expressions in M, allowing the exact extrapolation to the infinite two-dimensional surface. We have numerically investigated all possible relative values that V, W, and U may have whether attractive or repulsive. A set of phases occurs when V, W, and U are found to satisfy a certain set of inequalities defining an energy region. We have obtained all possible energy regions and the possible phases occurring in every region. Within a given energy region, let {θ01, θ1, β1, γ1} and {θ02, θ2, β2, γ2} be two consecutive phases. The value μ12 of μ at the transition is the one for which the entropy is a local maximum. In all cases, (θ02-θ01) μ12=- V (θ2-θ1)- W (β2-β1)- U (γ2-γ1). Consider an adsorption system with no surface reconstruction and at thermodynamic equilibrium. Providing first-, second- and third- neighbor interactions are predominant, it is sufficient to determine experimentally the patterns and the pressure at the transitions, to obtain a number of linear relations between the various interaction energies. Since there are four interaction energies, V 0, V, W and U, there may be cases where it is possible to determine all of these energies.
PHOTO-IRRADIATION EFFECTS ON PREPARATION OF COLLOIDAL QUANTUM DOTS AND THEIR SURFACE MODIFICATION
Authors: KIM D. , TERATANI N. , MIZOGUCHI K. , NISHIMURA H. , NAKAYAMA M.
Published: July 2002

We have investigated the possibility of size control of CdS and PbS quantum dots (QDs) with a narrow size distribution and the influence of the surface modification of the dots on their luminescence properties. The reduction of the size-distribution width of the CdS QDs grown in polyvinylpyrrolidone or polyvinyl alcohol solutions was succeeded by a size-selective photoetching. We controlled the size of the CdS QDs with the narrow distribution by changing the initial condition of the sample preparation and the irradiation-light energy. The QDs of PbS were grown with the different disperse agents and growth temperature. The band-edge emission is strongly activated by the surface modification of the CdS QDs.
CRYSTALLIZATION BEHAVIOR OF A BULK AMORPHOUS Zr64Cu18Ni10Al8 ALLOY
Authors: WU SHYUE SHENG , TU CHIH-CHUNG
Published: July 2002

The bulk amorphous Zr 64 Cu 18 Ni 10 Al 8 alloy with a diameter of 5 mm was successfully obtained by an injection-casting method. The equilibrium crystallization temperature and the associated activation energy of the amorphous alloy were determined using differential scanning calorimetry and Kissinger's peak shift method. The mechanical properties were determined by microhardness. The results show that the bulk amorphous Zr 64 Cu 18 Ni 10 Al 8 alloy, the glass transition temperature is 380°C, the crystallization temperature is 482°C, the crystallization temperature at infinitesimal heating rate is extrapolated to be 442°C, the associated activation energy is 103 kJ/mol, and the Vickers hardness is 540 for the Zr 64 Cu 18 Ni 10 Al 8 bulk amorphous alloy. The energy barrier of crystallization for the amorphous Zr-based alloy is much less than the amorphous Fe- and Ti- based alloy. The hardness value of is 1.6 times larger than the cast titanium and steel. Therefore hopefully we can develop these bulk amorphous alloy into the application on sporting goods, micro-mechanical devices and aerospace industries.
THE EFFECT OF THE THIRD DIMENSION ON ROUGH SURFACES FORMED BY SEDIMENTING PARTICLES IN QUASI-TWO-DIMENSIONS
Authors: MCCLOUD K. V. , KURNAZ M. L.
Published: July 2002

The roughness exponent of surfaces obtained by dispersing silica spheres into a quasi-two-dimensional cell is examined. The cell consists of two glass plates separated by a gap, which is comparable in size to the diameter of the beads. Previous work has shown that the quasi-one-dimensional surfaces formed have two roughness exponents in two length scales, which have a crossover length about 1 cm. We have studied the effect of changing the gap between the plates to a limit of about twice the diameter of the beads. If the conventional scaling analysis is performed, the roughness exponent is found to be robust against changes in the gap between the plates; however, the possibility that scaling does not hold should be taken seriously.
X-Ray Absorption Fine Structure in FeTiO3
Authors: Berry Frank J. , Bohorquez Alberto , Mcmanus Julia , Wynn Paul , Bilsborrow Robert
Published: July 2002

The recent report1 that the Fe K-edge X-ray absorption fine structure (XAFS) recorded from FeTiO 3 are best interpreted in terms of the presence of Fe 3+ is erroneous. The X-ray absorption near edge structure recorded at both the Fe K- and Ti K-edges are consistent with the presence of Fe 2+ and Ti 4+. The results are endorsed by 57 Fe Mössbauer spectroscopy. The compound FeTiO 3 is accurately formulated as Fe 2+ Ti 4+ O 3.
A VISION BASED SYSTEM FOR OBJECT DETECTION IN UNDERWATER IMAGES
Authors: FORESTI G. L. , GENTILI S.
Published: July 2002

In this paper, a vision-based system for underwater object detection is presented. The system is able to detect automatically a pipeline placed on the sea bottom, and some objects, e.g. trestles and anodes, placed in its neighborhoods. A color compensation procedure has been introduced in order to reduce problems connected with the light attenuation in the water. Artificial neural networks are then applied in order to classify in real-time the pixels of the input image into different classes, corresponding e.g. to different objects present in the observed scene. Geometric reasoning is applied to reduce the detection of false objects and to improve the accuracy of true detected objects. The results on real underwater images representing a pipeline structure in different scenarios are shown. The presence of seaweed and sand, different illumination conditions and water depth, different pipeline diameter and small variations of the camera tilt angle are considered to evaluate the algorithm performances.
A DISCRETE HMM FOR ONLINE HANDWRITING RECOGNITION
Authors: YASUDA H. , TAKAHASHI K. , MATSUMOTO T.
Published: July 2002

A fast HMM algorithm is proposed for online handwritten character recognition. After preprocessing the input strokes are discretized so that a discrete HMM is used. This particular discretization naturally leads to a simple procedure for assigning the initial state and state transition probabilities. In the training phase, complete marginelization with respect to state is not performed. A criterion based on normalized maximum likelihood ratio is given for deciding when to create a new model for the same character in the learning phase, in order to cope with stroke order variations and large shape variations. Experiments are done on the Kuchibue data base from Tokyo University of Agriculture and Technology. The algorithm appears to be very robust against stroke number variations and have reasonable robustness against stroke order variations and large shape variations. A drawback of the proposed algorithm is its memory requirement when the number of character classes and their associated models becomes large. Density tying is discussed in order to overcome this problem.
A FAST AND SECURE IMAGE HIDING SCHEME BASED ON LSB SUBSTITUTION
Authors: CHANG CHIN-CHEN , LIN MIN-HUI , HU YU-CHEN
Published: July 2002

The improving technology and the ubiquity of the Internet have allowed more and more people to transmit data via the Internet. The contents of the transmission can be in the form of words, voices, images, or even computer animation. To protect the contents from interceptors' attention, the image hiding technology thus emerged. Some contents transmitted via the Internet can be confidential data such as highly valued product design blueprints or war plans, so it is important to pay more attention to the security of the transmitted data, or what we called secret image in this paper. The point of this paper is to enhance the security of the secret image without causing too much distortion to the host image and in the meantime to shorten the image hiding process time. For better protection, we adopted encryption process DES. In addition, we used greedy algorithm to shorten hiding process and to protect the host image from being severely distorted.

To test our proposed method to see whether it indeed achieved its objective, we used two sets of images in our experiment. The results of the experiments showed, when k = 2, our PSNR is close to that of Wang et al.'s optimal LSB substitution, but is not significantly different from that of simple LSB substitution. However, our method took approximately only 1/7 of the time consumed by Wang et al. When k = 3, our PSNR is significantly higher than that of simple LSB substitution. The experimental results confirmed that our method could effectively protect host image quality and shorten the overall hiding time when it enhanced the security of the secret image.
ON THE OPTIMAL STRUCTURE DESIGN OF MULTILAYER FEEDFORWARD NEURAL NETWORKS FOR PATTERN RECOGNITION
Authors: CHEN DAQING , BURRELL PHILLIP
Published: July 2002

In this survey paper, the-state-of-the-art of the optimal structure design of Multilayer Feedforward Neural Network (MFNN) for pattern recognition is reviewed. Special emphasis is laid on the scale-limited MFNN and the internal representation and decision boundary-based design methodologies. A comprehensively comparative study of the main characteristics of each method is presented. Also, future research directions are outlined.