bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Nonlinear Response of a Flexible Connecting Rod
Authors: Chen Jen-San , Chian Chu-Hsian
Published: January 2004

In two recent papers (Chen, J.-S., and Chen, K.-L., 2001, “The Role of Lagrangian Strain in the Dynamic Response of a Flexible Connecting Rod,” ASME Journal of Mechanical Design, 123, pp. 542–548; Chen, J.-S., and Huang, C.-L., 2001, “Dynamic Analysis of Flexible Slider-Crank Mechanisms With Nonlinear Finite Element Method,” Journal of Sound and Vibration, 246, pp. 389–402) we reported that previous researches of others on the dynamic response of a flexible connecting rod may have overestimated the deflections by ten folds when the crank rotates near the bending natural frequency of the connecting rod because terms of significant order of magnitude were ignored inadequately. While the findings in (Chen, J.-S., and Chen, K.-L., 2001, “The Role of Lagrangian Strain in the Dynamic Response of a Flexible Connecting Rod,” ASME Journal of Mechanical Design, 123, pp. 542–548; Chen, J.-S., and Huang, C.-L., 2001, “Dynamic Analysis of Flexible Slider-Crank Mechanisms With Nonlinear Finite Element Method,” Journal of Sound and Vibration, 246, pp. 389–402.) were obtained via numerical simulations, the present paper emphasizes the analytical approach with an aim to exploring the physical insights behind these numerical results. The equations of motion are first derived by applying Hamilton’s principle with all high order terms in the strain energy function being retained. After careful examination of the order of magnitude of each term, the coupled equations are simplified to a single one in terms of the transverse deflection, which turns out to be a Duffing equation under parametric and external excitations simultaneously. Closed-form approximations of the dynamic response are then derived by using multiple scale method. It is found that the combined effects of parametric and external excitations dominate the response when Ω is close to 0.5 and 1. Away from these two speed ranges, on the other hand, the response is dominated by the external excitation alone.
The Synthesis of Elliptical Gears Generated by Shaper-Cutters
Authors: Figliolini Giorgio , Angeles Jorge
Published: January 2004

The synthesis of elliptical gears is formulated using envelope theory by means of a suitable shaper-cutter with involute tooth profile. A general algorithm producing the pitch curves of elliptical gears and their rack with any number of lobes is proposed. Evolutes of pitch curves can be also obtained in order to choose a suitable shaper-cutter, even for pitch curves with concave-convex profiles. The complete synthesis of both meshing elliptical gears and their rack is reported, several graphical results being shown for design and analysis purposes. Computer animations are also available.
Direct Method of Inverse Eigenvalue Problems for Structure Redesign*
Authors: Liangsheng Wu
Published: January 2004

This paper studies an inverse design problem of a general eigenvalue of a dynamic system where the elements of the rigidity and mass matrices are linear with respect to a design vector b. The coefficients of spring and mass of a lumped parameters structure, the length and width, the radius, etc play the role of design parameters. For some specified eigenvalues and eigenvectors, the design parameter vector can be obtained and the rigidity and mass matrices of an initially designed structure can be reconstructed by solving linear algebra equations. The theory and method can not only be used for an in-line system, but it can also be used for an inverse vibration design of a complex structure.
Bayesian Surrogates Applied to Conceptual Stages of the Engineering Design Process
Authors: Pacheco Jorge E. , Amon Cristina H. , Finger Susan
Published: January 2004

During the conceptual design stages, designers often have incomplete knowledge about the interactions among design parameters. We are developing a methodology that will enable designers to create models with levels of detail and accuracy that correspond to the current state of the design process. Thus, designers can create a rough surrogate model when only a few data points are available and then refine the model as the design progresses and more information becomes available. These surrogates represent the system response when limited information is available and when few realizations of experiments or numerical simulations are possible. This paper presents a covariance-based approach for building multistage surrogates in the conceptual design stages when bounds for the response are not available a priori. We test the methodology using a one-dimensional analytical function and a heat transfer problem with an analytical solution, in order to obtain error measurements. We then illustrate the use of the methodology in a thermal design problem for wearable computers. The surrogate model enables the designer to understand the relationships among the design parameters.
A Simplified Approach to Estimate Limiting Drawing Ratio and Maximum Drawing Load in Cup Drawing
Authors: Leu Daw-Kwei , Wu Jen-Yu
Published: January 2004

A new and practically applicable equation, including the normal anisotropy R, the strain hardening exponent n, the friction coefficient μ, and the bending factor t0/rd for estimating the limiting drawing ratio LDR (a measure of drawability of sheet metal) in cup drawing of a cylindrical cup with a flat-nosed punch is derived by an elementary theory of plasticity in an explicit form. Whiteley’s and Leu’s equations for estimating the LDR, and Hill’s upper limit value of LDR, all are the special cases of the derived equation. The estimation of LDR agrees well with the experiment. It is shown that the most important parameters for LDR are the normal anisotropy R and friction coefficient μ, however the strain hardening exponent n has little effect on the LDR. On the other hand, a new and simple equation, incorporating the derived LDR and the critical drawing load Pc, for estimating the maximum drawing load Pd at a certain drawing ratio is derived. It also agrees well with the experiment. It is thereby possible to better understand and control the drawing limit of sheet metal in industry necessity.
T Cell Activation by Lipopeptide Antigens
Authors: Moody D. Branch , Young David C. , Cheng Tan-Yun , Rosat Jean-Pierre , Roura-mir Carme , O'Connor Peter B. , Zajonc Dirk M. , Walz Andrew , Miller Marvin J. , Levery Steven B. , Wilson Ian A. , Costello Catherine E. , Brenner Michael B.
Published: January 2004

Unlike major histocompatibility proteins, which bind peptides, CD1 proteins display lipid antigens to T cells. Here, we report that CD1a presents a family of previously unknown lipopeptides from
Mycobacterium tuberculosis
, named didehydroxymycobactins because of their structural relation to mycobactin siderophores. T cell activation was mediated by the αβ T cell receptors and was specific for structure of the acyl and peptidic components of these antigens. These studies identify a means of intracellular pathogen detection and identify lipopeptides as a biochemical class of antigens for T cells, which, like conventional peptides, have a potential for marked structural diversity.
Extensive Gene Traffic on the Mammalian X Chromosome
Authors: Emerson J. J. , Kaessmann Henrik , Betrán Esther , Long Manyuan
Published: January 2004

Mammalian sex chromosomes have undergone profound changes since evolving from ancestral autosomes. By examining retroposed genes in the human and mouse genomes, we demonstrate that, during evolution, the mammalian X chromosome has generated and recruited a disproportionately high number of functional retroposed genes, whereas the autosomes experienced lower gene turnover. Most autosomal copies originating from X-linked genes exhibited testis-biased expression. Such export is incompatible with mutational bias and is likely driven by natural selection to attain male germline function. However, the excess recruitment is consistent with a combination of both natural selection and mutational bias.
Multimodal Signals: Enhancement and Constraint of Song Motor Patterns by Visual Display
Authors: Cooper Brenton G. , Goller Franz
Published: January 2004

Many birds perform visual signals during their learned songs, but little is known about the interrelationship between visual and vocal displays. We show here that male brown-headed cowbirds (Molothrus ater) synchronize the most elaborate wing movements of their display with atypically long silent periods in their song, potentially avoiding adverse biomechanical effects on sound production. Furthermore, expiratory effort for song is significantly reduced when cowbirds perform their wing display. These results show a close integration between vocal and visual displays and suggest that constraints and synergistic interactions between the motor patterns of multimodal signals influence the evolution of birdsong.
Evidence That Nitric Acid Increases Relative Humidity in Low-Temperature Cirrus Clouds
Authors: Gao R. S. , Popp P. J. , Fahey D. W. , Marcy T. P. , Herman R. L. , Weinstock E. M. , Baumgardner D. G. , Garrett T. J. , Rosenlof K. H. , Thompson T. L. , Bui P. T. , Ridley B. A. , Wofsy S. C. , Toon O. B. , Tolbert M. A. , Kärcher B. , Peter Th. , Hudson P. K. , Weinheimer A. J. , Heymsfield A. J.
Published: January 2004

In situ measurements of the relative humidity with respect to ice (RH
i
) and of nitric acid (HNO
3
) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RH
i
values show a sharp increase to average values of over 130% in both cloud types. These enhanced RH
i
values are attributed to the presence of a new class of HNO
3
-containing ice particles (Δ-ice). We propose that surface HNO
3
molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. Δ-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including Δ-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.
Snapshots of DsbA in Action: Detection of Proteins in the Process of Oxidative Folding
Authors: Kadokura Hiroshi , Tian Hongping , Zander Thomas , Bardwell James C. A. , Beckwith Jon
Published: January 2004

DsbA, a thioredoxin superfamily member, introduces disulfide bonds into newly translocated proteins. This process is thought to occur via formation of mixed disulfide complexes between DsbA and its substrates. However, these complexes are difficult to detect, probably because of their short-lived nature. Here we show that it is possible to detect such covalent intermediates in vivo by a mutation in DsbA that alters
cis
proline-151. Further, this mutant allowed us to identify substrates of DsbA. Alteration of the
cis
proline, highly conserved among thioredoxin superfamily members, may be useful for the detection of substrates and intermediate complexes in other systems.
Nota Bene: Horrible Achievement
Authors: Ash Caroline
Published: January 2004

Bodysnatchers
. BBC1. Aired November, December 2003.

This three-part television series presents a variety of horrific case studies about organisms that parasitize humans.
Accuracy of task recall for epidemiological exposure assessment to construction noise
Authors: Reeb-Whitaker C K , Seixas N S , Sheppard L , Neitzel R
Published: January 2004

Aims:To validate the accuracy of construction worker recall of task and environment based information; and to evaluate the effect of task recall on estimates of noise exposure.

Methods:A cohort of 25 construction workers recorded tasks daily and had dosimetry measurements weekly for six weeks. Worker recall of tasks reported on the daily activity cards was validated with research observations and compared directly to task recall at a six month interview.

Results:The mean LEQnoise exposure level (dBA) from dosimeter measurements was 89.9 (n = 61) and 83.3 (n = 47) for carpenters and electricians, respectively. The percentage time at tasks reported during the interview was compared to that calculated from daily activity cards; only 2/22 tasks were different at the nominal 5% significance level. The accuracy, based on bias and precision, of percentage time reported for tasks from the interview was 53–100% (median 91%). For carpenters, the difference in noise estimates derived from activity cards (mean 91.9 dBA) was not different from those derived from the questionnaire (mean 91.7 dBA). This trend held for electricians as well. For all subjects, noise estimates derived from the activity card and the questionnaire were strongly correlated with dosimetry measurements. The average difference between the noise estimate derived from the questionnaire and dosimetry measurements was 2.0 dBA, and was independent of the actual exposure level.

Conclusions:Six months after tasks were performed, construction workers were able to accurately recall the percentage time they spent at various tasks. Estimates of noise exposure based on long term recall (questionnaire) were no different from estimates derived from daily activity cards and were strongly correlated with dosimetry measurements, overestimating the level on average by 2.0 dBA.
The dissemination of anthrax from imported wool: Kidderminster 1900–14
Authors: Carter T
Published: January 2004

Background:A century ago anthrax was a continuing health risk in the town of Kidderminster. The distribution of cases in people and in animals provides an indication of the routes by which spores were disseminated. The response to these cases provides an insight into attitudes to an occupational and environmental risk at the time and can be compared with responses in more recent times.

Aims:To assess the distribution of anthrax cases associated with the use of contaminated wool and to review the response to them.

Methods:The area studied was Kidderminster, Worcestershire, England, from 1900 to 1914. Data sources were national records of the Factory Inspectorate and local records from the infirmary, Medical Officer of Health and inquest reports, and county agricultural records, supplemented by contemporary and later review articles. Case reports and summary data were analysed, and discussions and actions taken to improve precautions reviewed.

Results:There were 36 cases of anthrax, with five deaths, one of which was the sole case of the internal form of the disease. Cases of cutaneous anthrax were most frequently found in those handling raw wool, but they also occurred in workers at later stages of the spinning process and in people with little or no recorded exposure to contaminated wool. Limited precautionary measures were in place at the start of the study period. Some improvements were made, especially in the treatment of infections, but wool with a high risk of anthrax contamination continued to be used and cases continued to arise. Major changes were made to the disposal of waste and to agricultural practice in contaminated areas to curtail outbreaks in farm animals.

Conclusions:The introduction of anthrax as a contaminant of imported wool led not only to cases in the highly exposed groups of workers but also to cases in other members of the population and in farm animals. The measures taken during the study period reduced fatalities from cutaneous anthrax but did not eliminate the disease. Public concern about the cases was muted.
Lung cancer and dust exposure: results of a prospective cohort study following 3260 workers for 50 years
Authors: Moshammer H , Neuberger M
Published: January 2004

Aims:To study the lasting health impact of occupational dust exposure on life expectancy and specific causes of death.

Methods:Male Viennese workers, selected at age ⩾40 (mean 54) years during preventive check-ups between 1950 and 1960, were followed prospectively until death. Half of them (1630) were exposed at work to (non-fibrous) particulates, while the non-exposed workers were matched for year, age, and smoking status at the start of observation.

Results:Average life expectancy of those exposed was 1.6 years less than that of those non-exposed. Only a small part of this decrease in life expectancy (hazards ratios in brackets) was related to acknowledged occupational diseases such as silicosis and silicotuberculosis (67.12). Chronic obstructive lung disease (1.82) and cancer of the lung (1.42) and stomach (1.77) were found more frequently among those exposed.

Conclusions:Results support the hypothesis that high exposure to insoluble particulates such as silica in the metal, glass, ceramics, and stone industries promotes bronchial cancer and chronic obstructive pulmonary disease. The finding of an increased incidence of stomach cancer might be related to particles swallowed after clearance from the airways.
Update of a prospective study of mortality and cancer incidence in the Australian petroleum industry
Authors: Gun R T , Pratt N L , Griffith E C , Adams G G , Bisby J A , Robinson K L
Published: January 2004

Aims:To update the analysis of the cohort mortality and cancer incidence study of employees in the Australian petroleum industry.

Methods:Employees from 1981 to 1996 were traced through the Australian National Death Index and the National Cancer Statistics Clearing House. Cause specific mortality and cancer incidence were compared with those of the Australian population by means of standardised mortality ratios (SMRs) and standardised incidence ratios (SIRs). Associations between increased incidence of specific cancers and employment in the petroleum industry were tested by trends according to period of first employment, duration of employment, latency, and hydrocarbon exposure, adjusting for personal smoking history where appropriate. Total follow up time was 176 598 person-years for males and 10 253 person-years for females.

Results:A total of 692 of the 15 957 male subjects, and 16 of the 1206 female subjects had died by the cut off date, 31 December 1996. In males, the all-cause SMR and the SMRs for all major disease categories were significantly below unity. There was a non-significant increase of the all-cancer SIR (1.04, 95% CI 0.97 to 1.11). There was a significant increase of the incidence of melanoma (SIR 1.54, 95% CI 1.30 to 1.81), bladder cancer (SIR 1.37, 95% CI 1.00 to 1.83), and prostate cancer (SIR 1.19, 95% CI 1.00 to 1.40), and a marginally significant excess of pleural mesothelioma (SIR 1.80, 95% CI 0.90 to 3.22), leukaemia (SIR 1.39, 95%CI 0.91 to 2.02), and multiple myeloma (SIR 1.72, 95% CI 0.96 to 2.84).

Conclusions:Most cases of mesothelioma are probably related to past exposure to asbestos in refineries. The melanoma excess may be the result of early diagnosis. The excess bladder cancer has not been observed previously in this industry and is not readily explained. The divergence between cancer incidence and cancer mortality suggests that the “healthy worker effect” may be related to early reporting of curable cancers, leading to increased likelihood of cure and prolonged mean survival time.
The association between sex segregation, working conditions, and sickness absence among employed women
Authors: Hensing G , Alexanderson K
Published: January 2004

Aims:To analyse the association between sickness absence and sex segregation of occupation and of work site, respectively, and to analyse work environmental factors associated with high sickness absence.

Methods:The study group consisted of 1075 women employed as nurses, assistant nurses, medical secretaries, or metal workers who answered a questionnaire comprising 218 questions on women’s health and living conditions. Sickness absence was collected from employers’ and social insurance registers.

Results:Women working in the male dominated occupation had in general higher sickness absence compared to those working in female dominated occupations. However, metal workers at female dominated work sites had 2.98 (95% CI 2.17 to 3.79) sick-leave spells per woman and year compared to 1.70 (95% CI 1.29 to 2.10) among those working with almost only men. In spite of a better physical work environment, female metal workers at a female dominated work site had a higher sickness absence than other women, which probably could be explained by the worse psychosocial work environment. Working with more women also had a positive association to increased frequency of sick-leave spells in a multivariate analysis including several known indicators of increased sick-leave.

Conclusions:There was an association between sickness absence and sex segregation, in different directions at the occupational and work site level. The mechanism behind this needs to be more closely understood regarding selection in and out of an occupation and a certain work site.
Incidence of cancer among Swedish military and civil personnel involved in UN missions in the Balkans 1989–99
Authors: Gustavsson P , Talbäck M , Lundin A , Lagercrantz B , Gyllestad P-E , Fornell L
Published: January 2004

Leukaemia cases among European UN soldiers in the Balkans have been related hypothetically to exposure to depleted uranium. This study was performed to investigate the risk of cancer among Swedish personnel (8750 men and 438 women) involved in UN missions in the Balkans 1989–99. The overall incidence of cancer was slightly higher than expected; 34 cancers were observed and 28.1 were expected based on national cancer rates. Among military men, there were eight cases of testicular cancer versus 4.6 expected. There was one case of chronic myeloid leukaemia, and no cases of acute leukaemia. The overall risk of cancer was increased in a subgroup of 648 men taking part in convoy operations, based on only five cancers at four different sites. The study gives no support for the hypothesis that UN service in the Balkans could lead to haematolymphatic malignancies after short latency. However, no exposure assessment was performed, and future follow up is necessary for evaluation of long term risks.
Psychosocial work environment and indoor air problems: a questionnaire as a means of problem diagnosis
Authors: Lahtinen M , Sundman-Digert C , Reijula K
Published: January 2004

Aims:To examine the relation between the psychosocial work environment and the perceived indoor air problems measured by a questionnaire survey; and to discuss the role of a questionnaire as a means to enhance collaboration in the challenging multiprofessional process of solving indoor air problems.

Methods:The research material comprises surveys conducted in 1996–99 in 122 office workplaces with 11 154 employees.

Results:The association between the psychosocial work environment measured by the Indoor Air Questionnaire (MM-40) and the occupants’ complaints concerning indoor air as well as symptoms attributed to indoor air was significant. Those who perceived their psychosocial work environment more negatively had more complaints regarding the indoor environment and more symptoms attributed to the indoor air. The association was detected among both genders, in every age group, among smokers and non-smokers, and respondents with an allergic or a non-allergic background.

Conclusions:Results support the hypothesis that psychosocial factors in the work environment play a significant role in indoor air problems at workplaces. The survey data can be used as a reference database for future studies, and in occupational health care practice when the working conditions of individual workplaces are estimated. The MM-40 could be useful as a practical screening method in field work for analysing the role of the psychosocial work environment among the different background factors of an indoor air problem. However, in order to interpret and evaluate the significance of the results concerning a single workplace, more information on the organisation is needed, as well as cooperation and discussions with the staff. Further studies of the reliability and validity of the psychosocial questions in MM-40 are also needed.
Attention and working memory in resident anaesthetists after night duty: group and individual effects
Authors: Bartel P , Offermeier W , Smith F , Becker P
Published: January 2004

Aims:To investigate the effects of a single period of night duty on measures of attention and working memory in a group of residents (registrars) in anaesthesiology. Emphasis was placed on individual deficits using a reference point of the equivalent effect of a blood alcohol concentration (BAC) >0.05% determined by other researchers.

Methods:There were 33 subjects aged 26–42 years. Night duty was performed on a weekly basis. Baseline assessments were conducted at either 08 15 or 08 55 preceding night duty and repeated 24–25 hours later, just after the completion of duty. Questionnaires included items regarding duration of sleep and the Stanford Sleepiness Scale. A battery of four reaction time (RT) tasks of increasing difficulty, lasting approximately 35 minutes, was administered on a personal computer. These ranged from simple RT to progressively more complex RT tasks incorporating working memory. A significant change was regarded as >15% deterioration in respect of speed or accuracy.

Results:The mean duration of sleep preceding night duty was 7.04 hours and 1.66 hours during the period of night duty. Intergroup comparisons revealed significant prolongation in mean response speed in the first three tests. Mean accuracy was significantly reduced only in respect of the two more complex tests. A >15% deterioration in response speed occurred in up to 30% of subjects on a single task, rising to 52% (17/33) overall. Deterioration occurred in a patchy distribution in most subjects, involving no more than one or two of the four tasks. As regards accuracy, the prevalence of deterioration increased with task complexity.

Conclusions:Results are in general agreement with previous group analyses. A new dimension was added by the analysis of a broad spectrum of individual response to sleep deprivation. The effects of sleep loss in residents cannot be overlooked, even in a relatively benign work schedule.
Risk of selected birth defects by maternal residence close to power lines during pregnancy: Table 1
Authors: Blaasaas K G , Tynes T , Lie R T
Published: January 2004

Aims:To evaluate selected birth outcomes from a published Norwegian cohort study in a nested case-control design with improved exposure data.

Methods:Two controls matched for sex, year of birth, and municipality were selected randomly for children with the following defects: central nervous system (CNS) defects, cardiac defects, respiratory system defects, oesophageal defects, and clubfoot. The distances between maternal addresses, during pregnancy, and power lines were obtained from maps mainly of scale 1:5000. The magnetic fields in the residences were estimated based on distance, current, voltage, and configuration.

Results:The highest increased risks were seen for hydrocephalus (OR 1.73, 95% CI 0.26 to 11.64) and for cardiac defects (OR 1.54, 95% CI 0.89 to 2.68).

Conclusion:This study does not support the hypothesis that residential exposure to electromagnetic fields from power lines causes any of the investigated outcomes.
A six year follow up study of the subclinical effects of carbon disulphide exposure on the cardiovascular system
Authors: Takebayashi T , Nishiwaki Y , Uemura T , Nakashima H , Nomiyama T , Sakurai H , Omae K
Published: January 2004

Aims:A six year prospective cohort study was conducted to clarify whether the current carbon disulphide (CS2) exposure level is low enough to prevent subclinical health impairment and/or to ameliorate health effects due to previous high exposure. This paper describes the effects on the cardiovascular systems.

Methods:The study subjects were 432 male workers exposed to CS2and 402 non-exposed workers in Japan, all of whom were examined in 1992–93. A total of 251 CS2exposed, 140 formerly exposed, and 359 non-exposed workers participated in the follow up survey (follow up rate 89.9%) in 1998–99. Mean duration of exposure was 19.3 years at the end the study. Mean CS2and 2-thiothiazolidine-4-carboxylic acid (TTCA) concentrations were 5.0 ppm and 1.6 mg/g creatinine. Health items examined were serum biochemical indices including lipids and coagulation-fibrinolysis factors, blood pressure, aortic stiffness, ophthalmography, and electrocardiography at rest and after Master’s double 2 step test. Potential confounding factors were adjusted for.

Results:Incidence of ischaemic findings, defined as Minnesota codes I, IV1–3, V1–3(at rest and after the load), or receiving treatment for ischaemia, was significantly higher in the exposed workers, especially for the spinning/refining workers (adjusted OR 2.1; 95% CI 1.1 to 4.0) or the highest quartile of six year mean TTCA (adjusted OR 3.9; 95% CI 1.8 to 8.7), although the observed increase in risk was diminished when rigorous ECG criteria were applied. Incidence of retinal microaneurysm was increased with marginal significance. Among cardiovascular risk factors we examined, only blood pressure values were significantly increased in the exposed workers.

Conclusions:Increased risk of ischaemic electrocardiogram findings among Japanese viscose rayon workers was observed. Although its clinical significance is to be discussed, the current Japanese occupational exposure limit for CS2, 10 ppm, would be high to prevent subclinical cardiovascular effects in this study population.
The transmission of tuberculosis in the light of new molecular biological approaches: Table 1
Authors: Seidler A , Nienhaus A , Diel R
Published: January 2004

This review briefly summarises the recent achievements in tuberculosis epidemiology associated with the introduction of molecular methods, and considers the implications of these methods for the understanding of occupational tuberculosis transmission. Special attention is paid to the relative contribution of recently transmitted tuberculosis; risk factors for recent transmission; and the occurrence and frequency of exogenous reinfection. There is a need for occupational epidemiological studies, which should combine the methods of “classical” epidemiology with those of molecular epidemiology.
Lung cancer mortality in UK nickel-cadmium battery workers, 1947–2000
Authors: Sorahan T , Esmen N A
Published: January 2004

Aims:To investigate mortality from lung cancer in nickel-cadmium battery workers in relation to cumulative exposure to cadmium hydroxide.

Methods:The mortality of a cohort of 926 male workers from a factory engaged in the manufacture of nickel-cadmium batteries in the West Midlands of England was investigated for the period 1947–2000. All subjects were first employed at the plant in the period 1947–75 and employed for a minimum period of 12 months. Work histories were available for the period 1947–86; the factory closed down in 1992. Two analytical approaches were used, indirect standardisation and Poisson regression.

Results:Based on serial mortality rates for the general population of England and Wales, significantly increased mortality was shown for cancers of the pharynx (observed (Obs) 4, expected (Exp) 0.7, standardised mortality ratio (SMR) 559, p<0.05), non-malignant diseases of the respiratory system (Obs 61, Exp 43.0, SMR 142, p<0.05), and non-malignant diseases of the genitourinary system (Obs 10, Exp 4.1, SMR 243, p<0.05). Non-significantly increased SMRs were shown for lung cancer (Obs 45, Exp 40.7, SMR 111) and cancer of the prostate (Obs 9, Exp 7.5, SMR 116). Estimated cumulative cadmium exposures were not related to risks of lung cancer or risks of chronic obstructive pulmonary diseases, even when exposure histories were lagged first by 10, then by 20 years.

Conclusions:The study findings do not support the hypotheses that cadmium compounds are human lung carcinogens.
A mortality cohort study among workers in a graphite electrode production plant in Italy
Authors: Merlo D F , Garattini S , Gelatti U , Simonati C , Covolo L , Ceppi M , Donato F
Published: January 2004

Background:Graphite electrode manufacturing workers are exposed to coal tar and its volatiles containing a variety of polycyclic aromatic hydrocarbons (PAH), silica and graphite dusts, and asbestos.

Aims:To investigate mortality from cancer and other diseases among workers in a graphite electrode production plant in Italy.

Methods:A total of 1291 males actively employed between 1 January 1950 and 31 December 1989 who had worked at the plant for at least one year were studied. The follow up extended from 1950 to 1997. Standardised mortality ratios (SMR) and their 95% confidence intervals (CI) were computed using mortality rates for the Italian and regional male population.

Results:Excess mortality was observed for all causes (SMR 1.44, CI 1.32 to 1.56), all cancers (SMR 1.27, CI 1.07 to 1.50), liver cancer (SMR 4.19, CI 2.68 to 6.23), silicosis (SMR 66.39, CI 52.56 to 82.7), and cirrhosis and other chronic diseases of the liver (SMR 1.87, CI 1.31 to 2.59) in comparison with the national male population. When regional rates were used to calculate the number of expected deaths, SMRs remained higher for silicosis (SMR 57.32, 42.11 to 76.22), and liver cancer (SMR 2.57, 1.57 to 3.97). Mortality from silicosis was increased in workers hired at young ages (<25 years, SMR 81.79; 25–34 years, SMR 82.73), and in workers aged <45 at death (SMR 333.3, CI 159.8 to 613). Mortality from liver cancer increased threefold (SMR 3.11, CI 1.78 to 5.05) in workers with more than 10 years of employment at the plant during the manufacture of Karbate products.

Conclusions:Results support the association between excess mortality from silicosis and occupational exposure to siliceous sands experienced during graphite electrode manufacturing. The observed excess mortality from liver cancer is compatible, to some extent, with exposures that may have occurred during the manufacture of phenolic and furfuryl resins treated products, although a role of lifestyle factors and viral infections cannot be excluded.
Demonic semantics: using monotypes and residuals
Authors: Tchier F.
Published: January 2004

Relations and relational operators can be used to define the
semantics of programming languages. The
operations ∨ and ∘ serve to give angelic
semantics by defining a program to go right when there is a
possibility to go right. On the other
hand, the demonic
operations ⊔ and □
do the opposite: if there is a possibility to go wrong, a program
whose semantics is given by these operators will go wrong; it is
the demonic semantics. This type of semantics is known at
least since Dijkstra′s introduction of the language of guarded
commands. Recently, there has been a growing interest in demonic
relational semantics of sequential programs. Usually, a construct
is given an ad hoc semantic definition based on an intuitive
understanding of its behavior. In this note,
we show how the notion of relational flow diagram
(essentially a matrix whose entries are relations on the set of
states of the program), introduced by Schmidt, can be used to
give a single demonic definition for a wide range of programming
constructs. This research had originally been carried out by
J. Desharnais and F. Tchier (1996) in the
same framework of the binary homogeneous relations. We show that
all the results can be generalized by using the monotypes and the
residuals introduced by Desharnais et al. (2000).
On Volterra inequalities and their applications
Authors: Hącia Lechosław
Published: January 2004

We present certain variants of two‐dimensional and n‐dimensional Volterra integral
inequalities. In particular, generalizations of the
Gronwall inequality are obtained. These results are applied in
various problems for differential and integral equations.
A delayed mathematical model for testosterone secretion with feedback control mechanism
Authors: Mukhopadhyay Banibrata , Bhattacharyya Rakhi
Published: January 2004

A mathematical model describing the biochemical interactions of
the luteinizing hormone (LH), luteinizing hormone‐releasing hormone (LHRH), and testosterone
(T) is presented. The model structure consists of a negative
feedback mechanism with transportation and secretion delays of
different hormones. A comparison of stability and bifurcation
analysis in the presence and absence of delays has been performed.
Mathematical implications of castration and testosterone infusion
are also studied.
wEBMT: Developing and Validating an Example-Based Machine Translation System Using the World Wide Web
Authors: Way Andy , Gough Nano
Published: January 2004

We have developed an example-based machine translation (EBMT) system that uses the World Wide Web for two different purposes: First, we populate the system's memory with translations gathered from rule-based MT systems located on the Web. The source strings input to these systems were extracted automatically from an extremely small subset of the rule types in the Penn-II Treebank. In subsequent stages, the source, target translation pairs obtained are automatically transformed into a series of resources that render the translation process more successful. Despite the fact that the output from on-line MT systems is often faulty, we demonstrate in a number of experiments that when used to seed the memories of an EBMT system, they can in fact prove useful in generating translations of high quality in a robust fashion. In addition, we demonstrate the relative gain of EBMT in comparison to on-line systems. Second, despite the perception that the documents available on the Web are of questionable quality, we demonstrate in contrast that such resources are extremely useful in automatically postediting translation candidates proposed by our system.
"FREELY ELECTED IN FEAR": PRINCELY ELECTIONS AND POLITICAL POWER IN EARLY MODERN TRANSYLVANIA
Authors: Murdock Graeme
Published: January 2004

Transylvania's survival was threatened by both its Habsburg and Ottoman neighbors. Given this precarious international position, ruling princes required sufficient power to govern effectively, and also needed to maintain a broad consensus for their right to exercise authority over the diverse political elite. A successful balance of power between princes and the estates was built around the freedoms granted to a number of different churches, and around the right of the diet to elect princes. This article examines the elections of Gábor Bethlen and other Calvinist princes in Transylvania during the early seventeenth century. Even though these elections were rarely free or fair, they provided a key basis for the growing political authority of princes who were widely identified as divinely-appointed rulers. Transylvania thus provides a model of a competence for elective monarchy, a form of political organization often thought to lead inevitably to unstable and ineffective government.
THE WORLD OF THE TURKS DESCRIBED BY AN EYE-WITNESS: GEORGIUS DE HUNGARIA'S DIALECTICAL DISCOURSE ON THE FOREIGN WORLD OF THE OTTOMAN EMPIRE
Authors: Classen Albrecht
Published: January 2004

Georgius de Hungaria (b. 1422/23) went through extraordinary experiences while being a slave in Ottoman Turkey for the two decades after he had been captured in 1438. In his subsequent account, Tractatus de Moribus (first written down in 1481/82), he not only reflects upon his woeful experiences as a slave, but also provides detailed information about Ottoman culture. For some time Georgius seems to have been on the brink of converting to Islam and experienced forms of mystic visions that confirmed this new belief. But he eventually returned to Christianity and later, while writing his account, made every attempt to assert his firm adherence to Christian teachings. As a critical analysis of his treatise demonstrates, however, his open admiration of Ottoman culture is undeniable, and his sharp criticism of Islam ultimately proves to be the writer's self-defense against a deep-seated fear of having transgressed traditional European norms.
An inferential control scheme for optimizing the operation of boilers in multi-zone heating systems
Authors: Liao Z , Dexter A L
Published: January 2004

The impacts of boiler control on the overall performance of multi-zone heating systems have been studied using a simulation platform. Conventional boiler controllers have been investigated to determine the potential for optimization and to identify the key variables that should be taken into account. An inferential control scheme is accordingly proposed for use in multi-zone buildings where there is no measurement of the internal air temperature. The scheme estimates the overall average room temperature from available information, including boiler ” ring signals, external temperature and solar radiation. The output of the estimator is fed back to a PI controller that determines the hot water supply temperature setpoint. The estimator has been validated using experimental data obtained from different sources. It has been shown in simulation that this control scheme can signi” cantly reduce the energy consumption of heating systems and improve the overall control performance in terms of the thermal comfort.
Control design of open-cycle desiccant cooling systems using a graphical environment tool
Authors: Ginestet S , Stabat P , Marchio D
Published: January 2004

The control design of open-cycle desiccant systems involves three operation modes (ventilation, evaporative cooling and desiccant cooling) and two control parameters (regeneration temperature and air‘ ow rate) to match the cooling load. Speci” c HVAC component models have been added to SIMBAD library to run in Matlab/SimulinkÒ environment. The control strategy is de” ned using State‘ owÒprogram which is a user-friendly graphical tool. The whole simulation tool is used to set an adapted control strategy. The energy consumption and performance of the desiccant system are investigated for different cases of building loads, thermal inertia and climate during the cooling period.
Modelling the robustness properties of HVAC plant under feedback control
Authors: Gouda M M , Underwood C P , Danaher S
Published: January 2004

Most existing building simulation programs fail to capture sufficient of the underlying dynamics of nonlinear HVAC plant and some have restricted room space modelling capabilities for low-time-horizon analyses. In this work, a simplified model of a room space with hot water heating and a chilled ceiling system is developed for the main purpose of analysing control system response. The room model is based on a new approach to lumped capacitance modelling and the heating and chilled ceiling emitters are modelled using third-order descriptions. Control system components are treated in detail and both controllers are ‘tuned' at a nominal region of plant operation using a gradient-descent-based optimization procedure. Robustness qualities of the controllers are analysed with reference to extremes in plant operating conditions. A key feature of the work is the transparency of the modelling procedure, designed to have appeal to researchers as well as practitioners involved with HVAC control system design problems.
Advanced HVAC modeling with FemLab/Simulink/MatLab
Authors: van Schijndel A WM (Jos)
Published: January 2004

The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, non-linear and time dependent. In order to show how the program works, a complete code for solving a 2-D steady state heat transfer problem and the results are given. A validation study of a 2-D dynamic airflow problem, modeled using Navier Stokes and buoyancy is shown. All results show a good agreement with measurements. The use of Simulink is shortly discussed. Further advanced models include: a convective airflow around a convector, a thermal bridge model in Fem-Lab connected to a room model and PI controller in Simulink and an indoor airflow model in FemLab connected to an on/off controller in Simulink. At the conclusion the applications and the possible benefits for scientists, engineers and designers are discussed.
Modelling analysis on fin-tube heating coil of air handling unit
Authors: Yu B , de Jong W , van Paassen A HC
Published: January 2004

One of the fundamental components in engineering practice is the heat exchanger. The fin-tube heating coil of an air handling unit (AHU) is one important component in an HVAC system. In order to study the fault detection and diagnosis (FDD) strategy for an HVAC system, a general model of a fin-tube heat exchanger which is accurate and adaptable is necessary. On the basis of the physical conservation law, a dynamic discretization parameter model is built by SimulinkÒ. The heat exchanger is split into small elements to increase the accuracy of the model. The dynamic behaviour of the fin-tube heat exchanger is studied under the condition of step changes on the opening of the control valve. Research has been performed on an AHU and the simulation results show good accordance with the measurements. Correction on heat transfer coefficient has been introduced to increase the accuracy. MatlabÒ S-function is used to decrease the computational time of the simulation.
The importance of learning young: the use of nesting material in laboratory rats
Authors: Van Loo P. L. P. , Baumans V.
Published: January 2004

Unlike mice, adult laboratory rats do not spontaneously build nests when nesting material is offered. As a result, nesting material is often regarded as unsuitable environmental enrichment for laboratory rats. Wild rats and pet rats, however, have been observed to build complex nests from nesting material at hand. It was hypothesized that nest building in rats is an acquired behaviour, rather than genetically predisposed. To test this hypothesis, the progeny of three Wistar rats provided with nesting material (Kleenex tissues) during pregnancy and three standard-housed rats were divided in 34 same-sex couples with access to nesting material: (1) from the age of 8 weeks ( n=7); (2) from weaning ( n=8); (3) from birth ( n=17). The latter were subdivided into two groups after weaning, one provided with Kleenex tissues ( n=9), the other with Enviro-dri ( n=8). At the age of 12 weeks, all couples were provided with both types of nesting material for one week. Amount, shape, and soiling of the nesting material were scored on weekdays, and behaviour of the rats was scored twice weekly. Results indicated that the older the rats were when first provided with nesting material, the greater the amount of nesting material eaten and soiled, and the nests built were less elaborate. Overall, Enviro-dri was eaten less than Kleenex tissues. It is concluded that rats need to learn the proper use of nesting material. When provided from birth, nesting material is a suitable type of environmental enrichment for laboratory rats.