bluuebunny/crossref_metadata_2025 huggingface dataset:
An epidemiological study of salt miners in diesel and nondiesel mines
Authors: Gamble John , Jones William , Hudak James
Published: April 2007

A cross‐sectional study of 5 NaCl mines and 259 miners addressed the following questions: 1) Is there an association of increased respiratory symptoms, radiographic findings, and reduced pulmonary function with exposure to nitrogen dioxide (NO2) and/ or respirable particulate (RP) among these miners? 2) Is there increased morbidity of these miners compared to other working populations? Personal samples of NO2 and respirable particulate for jobs in each mine were used to estimate cumulative exposure. NO2 is used as a surrogate measure of diesel exposure.

Cough was associated with age and smoking, dyspnea with age; neither symptom was associated with exposure (years worked, estimated cumulative NO2 or RP exposure). Phlegm was associated with age, smoking, and exposure. Reduced pulmonary function (FVC, FEV1, peak, flow, FEF50, FEF75) showed no association with exposure. There was one case of small rounded and one case of small irregular opacities; pneumoconiosis was not analyzed further.

Compared to underground coal miners, above ground coal miners, potash miners, and nonmining workers, the study population after adjustment for age and smoking generally showed no increased prevalence of cough, phlegm, dyspnea, or obstruction (FEV1/FVC<0.7). Obstruction in younger salt miners and phlegm in older salt miners was elevated compared to nonmining workers. Mean predicted pulmonary function was reduced 2–4% for FEV1 and FVC, 7–13% for FEF50, and 18–22% for FEF75 below all comparison populations.
Classical syndromes in occupational medicine. Dimethylaminopropionitrile
Authors: Keogh James P.
Published: April 2007

Dimethylaminopropionitrile, used as a catalyst in the manufacture of polyurethane, was responsible for two epidemics of urinary retention, sexual dysfunction, and peripheral neuropathy in 1978. Most affected workers recovered promptly, but some have had persisting neuropathy, sexual and bladder dysfunction, and CNS symptoms. The mechanism of neurotoxicity appears to be interference with axoplasmic transport. The catalyst that caused the problem was withdrawn from the market after swift governmental action.
Mesothelioma among machinists in railroad and other industries
Authors: Mancuso Thomas F.
Published: April 2007

The first phase of the exploration of occupation‐related cancer among machinists was a retrospective review of deaths among members of the International Association of Machinists and Aerospace Workers in 1973, in which mesotheliomas were identified in workers in railroad and other industries. The second phase of the study initiated in 1982 was the establishment of a cohort study of machinists, employed for railroad company A, who were alive in January 1954. The cohort consisted of 197 machinists who had been employed by the same railroad prior to 1935 and observed to 1982. Causes of death were identified for 132 of the cohort. There were 18 alive and 47 not traced. Among the 29 cancer deaths, there were nine mesotheliomas and one endothelioma of the pleura.

Additional retrospective surveys of deaths among members of the railroad lodges of the international union, together with the cohort study, identified a total of 42 mesotheliomas, two endotheliomas of the pleura, and two cancers of the pleura among former railroad machinists.

Among the machinists employed in other industries, 16 mesotheliomas and six cancers of the pleura were identified.

For decades, machinists, by the nature of their craft, have had a high risk of occupation‐related cancer due to asbestos exposure.
Endotoxins in cotton: Washing effects and size distribution
Authors: Olenchock Stephen A. , Mull Judith C. , Jones William G.
Published: April 2007

Endotoxin contamination was measured in washed and unwashed cottons from three distinct growing areas, California, Mississippi, and Texas. The data show differences in endotoxin contamination based upon the geographic source of the cotton. It is also shown that washing bulk cotton before the carding process results in lower endotoxin in the cotton dust. Washing conditions can affect the endotoxin levels, and all size fractions of the airborne dust contain quantifiable endotoxin contamination. Endotoxin analyses provide a simple and reliable method for monitoring the cleanliness of cotton or airborne cotton dusts.
Lung cancer and occupation in Alameda County: A death certificate case‐control study
Authors: Milne K. L. , Sandler D. P. , Everson R. B. , Brown Steven M.
Published: April 2007

A case‐control comparison of lung cancer deaths versus deaths from all other cancers occurring in Alameda County, California, between 1958 and 1962 was conducted to investigate possible associations between lung cancer and occupation. Age‐adjusted, sex‐specific analyses indicated that a history of work in certain industries and occupations was associated with an increased risk of lung cancer. Among males, a significant positive association was found for glass, metal, furniture, professional and photographic equipment, rubber, leather and plastic manufacturing; water and air transportation; auto repair services; and construction. Specific occupations associated with a significant positive risk for males were: electricians, aircraft mechanics, painters, plasterers, machine operators, construction workers, bus and truck drivers, and guards and nightwatchmen. Among females, beauticians had a significantly high risk associated with lung cancer. These results were consistent with other studies of lung cancer related to occupation.
Benzene: A multipotential carcinogen. Results of long‐term bioassays performed at the bologna institute of oncology
Authors: Maltoni Cesare , Conti Barbara , Cotti Giuliano
Published: April 2007

Until recently, the incidence of benzene carcinogenicity was based only on the association between benzene occupational exposure and human leukemia, with many limited case reports and scanty epidemiological data. Available experimental studies up to 1976 on animals were rare, fragmentary, and inadequate, and had failed to prove the carcinogenic effects of benzene. However, an integrated project of long‐term carcinogenicity bioassays, begun in our laboratory in 1976 and still continuing, has shown that benzene produces a variety of tumors in rats including Zymbal gland carcinomas, carcinomas of the oral cavity, hepatocarcinomas, and possibly mammary carcinomas, lymphoreticular neoplasias, and other malignancies. Some of the tumors caused by benzene are uncommon or unusual in the breed of rats studied. Therefore benzene must be considered, under the studied experimental conditions, a strong multipotential carcinogen. The need for more experimental research is emphasized, particularly to assess the carcinogenic effects of low doses. Also recommended are more comprehensive epidemiological investigations, extended to all types of malignancies, and the application of adequate measures for primary prevention.
Roentgenographic evidence of asbestos exposure in a select population of railroad workers
Authors: Sepulveda Martin‐Jose , Merchant James A.
Published: April 2007

A volunteer population of 266 current and former railroad workers was examined with posteroanterior and oblique chest roentgenograms, and a comprehensive occupational smoking history. Seventy‐five percent of participants were over the age of 60, and 80% had fewer than 10 years of railroad‐related asbestos exposure. Roentgenographic evidence of asbestosis was found in only six workers (2%), whereas 20% had one or more pleural changes. Radiological abnormalities were related to latency period, age, and occupation, but not to smoking habit. While selection factors qualify the results of this study, the findings support the exposure and suggest a past and future history of asbestos mortality and morbidity among steam era railway workers.
Retirement disability among workers in a natural gas distribution company
Authors: Stanbury Martha , Liveright Timothy
Published: April 2007

Epidemiological investigations of occupational disability are severely limited because of the inherent difficulties in standardizing definitions of disability and because of the lack of appropriate comparison data. Nevertheless, occupational disability is of great concern to workers. An investigation of disability, defined as permanent retirement due to medical disability, among hourly employees of a natural gas distribution company was undertaken in response to a request by the employees' union. Because of the above limitations, a hypothesis‐generating rather than hypothesis‐testing approach was taken, utilizing both disability retirement incidence rates and a prevalence survey of the living disabled retirees. It was hypothesized from the analysis that this group of workers did experience an excess of retirement disability for the period 1971–1980 when compared to estimated disability incidence rates of the general Social Security insured population, and that this excess may have been due in part to an excess of musculoskeletal disabilities associated with occupational physical stresses and strains.
The mortality of coke workers in Britain
Authors: Hurley J. F. , McL. Archibald R. , Collings P. L. , Fanning D. M. , Jacobsen M. , Steele R. C.
Published: April 2007

Two studies of coke workers in Britain, comprising 6,767 men, gave similar results. The proportion of lung cancer deaths was about 20% higher than in manual workers generally. The excess occurred primarily among younger men. The ratio of lung cancers to all other cancers was also higher than expected, with limited data showing no evidence of excessive tobacco consumption. Death rates from other causes were generally favorable.

Overall the lung cancer death rates in oven workers were similar to those in non‐oven men, but in both studies some indications of a job‐specific excess were noted. These findings are compared with results from earlier studies in the United States and Canada where a much higher excess lung cancer mortality was found in oven men, particularly those with longer exposure times. We discuss possible reasons for the differences, and conclude that the results reported now contribute further evidence that exposure to coal carbonization fumes can cause lung cancer.
Mortality experience of vermont granite workers
Authors: Davis Letitia K. , Wegman David H. , Monson Richard R. , Froines John
Published: April 2007

The proportional mortality experience (1952–1978) of 969 deceased white male granite workers was compared with that of United States white males. Industrial hygiene information was combined with work histories to develop an estimate of lifetime granite dust exposure for each individual. Subjects were grouped into four cumulative exposure categories, and exposure‐response relationships were examined. Trends of increasing silicosis and tuberculosis with increasing lifetime exposure were observed. These are consistent with earlier findings. With the exception of excess suicide among granite workers dying before 1970, there was little evidence of association between other causes of death and employment in the granite industry.
Neurotoxic effects of organic solvents in exposed workers: An occupational, neuropsychological, and neurological investigation
Authors: Gregersen Per , Angelsø Brita , Nielsen Torben Elmo , Nørgaard Bente , Uldal Charlotte
Published: April 2007

Ninety‐eight workers, 65 exposed to organic solvents and 33 unexposed, were examined in order to assess possible neurotoxic signs and symptoms related to solvent exposure. The study group, who were selected according to the type of exposure in a given work process, had been exposed to various types of solvents. The groups were comparable in regard to age, the history of brain traumas and other neurological diseases, and alcohol consumption. The exposed workers had more symptoms of intellectual impairment, poorer performances in psychological tests, and more often signs of cerebral asthenopia. Symptoms and signs of peripheral neuropathy were not significantly increased. Solvent exposure and neurotoxic signs and symptoms were mildly correlated in the study group. Such dose–effect correlations have previously been proved only in a few epidemiological studies. This warrants reevaluation of the risk of developing toxic encephalopathy during prolonged occupational exposure to solvents.
An evaluation of the associations of leukemia and rubber industry solvent exposures
Authors: Checkoway Harvey , Wilcosky Timothy , Wolf Pamela , Tyroler Herman
Published: April 2007

Excessive leukemia mortality has appeared consistently in epidemiological studies of British and U.S. rubber industry workers. Attempts to identify causative factors have focused on exposure to benzene and other solvents. Interpretations of findings from these studies have often been influenced by expectations of a benzene/nonlymphocytic leukemia association, seen from previous work in other settings. However, data from the rubber industry studies have not been consistent with this expectation, as lymphocytic and nonlymphocytic leukemia have shown similar mortality excesses. Data from a small case‐control study of lymphocytic leukemia are presented to illustrate an approach that considers multiple solvent exposures. The associations with lymphocytic leukemia risk observed for a number of solvents, most notably carbon tetrachloride and carbon disulfide, were stronger than those detected for benzene.
Clinical observations in ethyl mercury chloride poisoning
Authors: Zhang Jimei
Published: April 2007

Forty‐one patients in the Peoples Republic of China were poisoned by ethyl mercury chloride, caused by the ingestion of rice that had been treated with the chemical. A dose‐response relationship was found. Five months after the onset of the intoxication, the patients were still in poor condition. They were treated with two chelating agents, sodium dimercaptopropane sulfonate (DMPS) and sodium dimercaptosuccinate (DMS), whose effects were compared. Both agents were effective but DMPS was superior. Although urinary excretion is not the best estimate of body burden in alkyl mercury intoxication, during chelation therapy urinary mercury was an effective indicator for diagnosis and assessment of the degree of intoxication. Chelation therapy was useful as long as the urinary mercury level was elevated.
Carcinogenicity of petroleum lubricating oil distillates: Effects of solvent refining, hydroprocessing, and blending
Authors: Halder Clive A. , Warne Thomas M. , Little Randel Q. , Garvin Paul J.
Published: April 2007

Certain refining processes were investigated to determine their influence on the dermal carcinogenic activity of petroleum‐derived lubricating oil distillates. Specifically, the effects of solvent refining, hydroprocessing, a combination of both processes, and the blending of oils processed using each technique were evaluated in standard mouse skin‐painting bioassays. The refining process used as well as the level or severity of treatment greatly influenced the carcinogenic outcome of processed lubricating oils. Solvent refining at severities normally used appeared to eliminate carcinogenicity. In contrast, hydroprocessing alone at mild levels of treatment was successful only in reducing the carcinogenic potency; severe hydroprocessing conditions were necessary to eliminate carcinogenic activity without the use of additional refining processes. Carcinogenic activity could also be eliminated by following moderate solvent refining with mild hydroprocessing. Blending of hydroprocessed oils with solvent‐refined oils resulted in a substantial reduction or even elimination of carcinogenic activity. However, the degree of protection obtained varied with the particular distillates used and appeared largely dependent on the inherent biological activity of the hydroprocessed oil.
Clinical studies of psychoorganic syndromes among workers with exposure to solvents
Authors: Flodin Ulf , Edling Christer , Axelson Olav
Published: April 2007

Exposure to organic solvents is common in industry. In Sweden, patients being evaluated for suspected solvent‐related diseases now constitute the largest group of patients seen at many clinics of occupational medicine, largely replacing classical occupational disorders. The findings in 128 consecutive patients with solvent exposure have been reviewed for the period 1978‐1981. The duration of exposure was 9 years or more for those with a diagnosis of psychoorganic syndrome (POS). “Incipient” POS was seen after a minimum exposure of 3 years duration. Patients with POS also had an increased frequency of polyneuropathy in comparison to those without any signs of POS. It was not possible to link these abnormalities with particular solvent exposure. Clinical chemistry tests were normal except for liver function tests in a few patients.
Lung function among asbestos cement factory workers: Cross‐sectional and longitudinal study
Authors: Siracusa Andrea , Cicioni Carla , Volpi Roberto , Canalicchi Patrizia , Brugnami Giuliana , Comodi Anna Rita , Abbritti Giuseppe
Published: April 2007

Ventilatory capacity tests and standardized respiratory questionnaires were used in 1973 and in 1980 to measure the effect of mixed dust exposure in the asbestos cement industry on respiratory symptoms and lung function in 65 exposed workers and 30 controls (exposed to polyvinyl chloride but not to asbestos). Workers exposed to asbestos had 1) a higher prevalence of breathlessness and chest pain, and a higher incidence of breathlessness; 2) lower 1980 values of forced vital capacity (FVC) (0.27‐0.83 liters) and forced expiratory volume in 1 sec (FEV1) (0.23‐0.62 liters); and 3) a faster decline (nearly 40 ml/year) in FVC and FEV1 between 1973 and 1980. The FVC annual decrease was 52.5 ml in the subjects with more than 15 years since first asbestos exposure, whereas it was 24.3 ml in those with less than 15 years, suggesting a faster decline after 15 years of exposure. The effect of asbestos exposure and smoking habits was less than additive as regards pulmonary function.
Pleural mesothelioma after a short interval from first exposure in the wine filter industry
Authors: Scansetti G. , Mollo F. , Tiberi G. , Andrion A. , Piolatto G.
Published: April 2007

Pleural mesotheliomas are usually reported after a long interval has passed since first exposure to asbestos. We, however, describe a case observed after a latent period of only 7.5 years in a worker exposed in a factory manufacturing auxiliary products for wine treatment, including chrysotile asbestos filters. The exposure to asbestos lasted 3‐4 months per year, during which airborne fiber concentrations ranged from 1 to 4 ff/cc in the patient's workplace. Due to the characteristics of the manufacturing process, the asbestos fibers were very thin in diameter. The patient also suffered from nasal breathing impairment. An examination of the literature showed that asbestos‐related mesotheliomas have been reported, albeit rarely, after less than 10 years from onset of exposure. Therefore, it is believed that this case should be related to past exposure to asbestos.
Acute effects of the work environment on pulmonary functions of swine confinement workers
Authors: Donham Kelley J. , Zavala Donald C. , Merchant James
Published: April 2007

A sample population of owner/operators of swine confinement production facilities (21 subjects in 21 different facilities) were tested by spirometry immediately before and after a 4‐hr work period. These confinement workers had statistically significant decrements in flow rates ranging from 3.3% (mean FVC) to 11.9% (mean FEF25–75). The air within the work environment was sampled for particulates and gases during the exposure period. There was suggestive evidence for a dose–response association between environmental exposures to carbon dioxide (CO2) and hydrogen sulfide (H2S). There was also some evidence for an additive relationship between smoking and work environment exposure on decline in lung function. The results of this study indicate that those working in swine confinement buildings experience irritation to the respiratory tract which is manifest by decreased flow rates. These findings suggest this exposure represents an emerging occupational health hazard. Further studies are warranted to assess the potential for chronic or irreversible damage to the respiratory tract.
Further cases of lead poisoning from wine
Authors: Perrelli G. , Capellaro E. , Pira E. , Maina G. , Vergnano P.
Published: April 2007

Lead intoxication has been reported to occur as a consequence of nonoccupational exposure, the source being mostly the leaching of lead from fluid containers in domestic use.

Three such cases are described, for which the cause has been identified to be in the lining of the vat used to contain home‐made wine. All cases are members of the same family.
The value of computerised axial tomography in the assessment of workers exposed to asbestos
Authors: Sluis‐Cremer Gerhard K. , Thomas Raymond Glyn , Schmaman Ian B.
Published: April 2007

Nineteen men who had been exposed to asbestos for long periods were subjected to an examination of the lungs by means of computerised axial tomography (CT). Some features of asbestos‐related disease are shown better on CT than on conventional roentgenograms, and occasionally features not shown at all on conventional films may be demonstrated on CT. It was concluded that CT may be useful in cases with borderline and doubtful signs on conventional films, and very occasionally in persons with long exposure who have normal conventional films.
Cervicobrachial disorders in certain occupations, with special reference to compression in the thoracic outlet
Authors: Sällström Johan , Schmidt Hans
Published: April 2007

One hundred ninety‐one workers in three different occupations were examined regarding presence of symptoms from the cervicobrachial region. Eighteen percent of the workers (27% of the female and 11% of the male workers) had symptoms of compression in the thoracic outlet. However, only 2% of all workers had pronounced symptoms of compression in the thoracic outlet. In addition, 27% of the workers (33% of the female and 23% of the male workers) had symptoms of other cervicobrachial disorders. Thus, 45% of the workers had symptoms from the cervicobrachial region. The workers with symptoms of compression in the thoracic outlet were significantly younger than the workers with other symptoms of cervicobrachial disorders, p < 0.01. No significant correlation was noted between vascular compression and symptoms of compression in the thoracic outlet.
Calcified plaques on mediastinal pleural reflections associated with asbestos dust exposure: Four case reports
Authors: Solomon Albert , Sluis‐Cremer G. K. , Thomas Raymond Glyn , Wright V. M. F.
Published: April 2007

Four cases with marked calcified plaque formation on the mediastinal pleural reflections are described and discussed.
Arterial hypertension and noise: A cross‐sectional study
Authors: Belli Stefano , Sani Luciano , Scarficcia Giorgina , Sorrentino Raffaela
Published: April 2007

The occurrence of permanent arterial hypertension was studied among the workers of a textile plant (490 subjects) exposed to high frequency noise, at levels often exceeding 100 dBA. The prevalence of the disease among these workers was compared to that observed in a reference series (450 subjects). A prevalence rate ratio equal to 1.34 (1.14–1.57) was estimated, taking into account several determinants of disease acting as confounding factors in the study. The results, which are in good agreement with those obtained in similar studies, are discussed.
Sources of respiratory insult in the poultry processing industry
Authors: Lenhart Steven W. , Olenchock Stephen A.
Published: April 2007

Although the agricultural community has focused a great deal of attention on improving the overall health of poultry for production purposes, the health of poultry workers has, by comparison, received less direct attention. Recent studies suggest that poultry workers who come in direct contact with live birds may be at risk of pulmonary dysfunction, including the development of chronic respiratory diseases.

Exposure of poultry workers to live birds results in potential pulmonary insult from a variety of allergenic and immunologic agents, as well as nuisance dust particles. In addition, marked levels of gram‐negative bacterial endotoxins and antibiotic‐resistant bacteria contaminate the occupational environment. Health care professionals should be aware of the potential sources of respiratory insult to workers in poultry processing and related industries.
Occupational hazards to health care workers: Report of a conference
Authors: Omenn Gilbert S. , Morris Sharon L.
Published: April 2007

Health care workers are exposed to an array of physical, chemical, biological, and psychosocial hazards. At a national conference in Seattle May 11–13, 1983, hospital occupational medicine programs were characterized as lagging far behind those in industries with comparable illness and injury rates. Participants and speakers recommended that health care workers be trained to recognize occupational hazards; that epidemiologic, laboratory, and clinical studies be undertaken to discern trends and establish the mechanisms of effects from hazardous exposures; and that adequate employee health and safety programs be established in health care settings.
Retired and former asbestos workers in Hawaii
Authors: Fournier‐Massey Gisele , Wong Gabriel , Hall Thomas C.
Published: April 2007

In 1979, a pilot survey defined respiratory status and unmet health care needs of retired and former male asbestos workers in Hawaii. Of 1,401 identified subjects, 741 were contacted and 411 were interviewed. Forty‐five subjects were between 39 and 54 years of age; 208, between 55 and 64; and 158, age 65 or more. They represented the main ethnic groups—Caucasian, Chinese, Filipino, Hawaiian and part‐Hawaiian, and Japanese—on Oahu.

Most subjects had had significant exposure to asbestos in a shipyard, and 83% were current nonsmokers (160 had never smoked, and 111 were ex‐smokers for ten years or more). Taking age and ethnicity into account, our group had more chronic respiratory and gastrointestinal problems than the comparable male population of Oahu in 1979, but fewer such problems than active shipyard workers elsewhere. These problems related primarily to current smoking status and secondarily to the length of asbestos exposure. Health care was available, but former workers used it less than retirees, despite having more symptoms. Very few abnormalities were reported by the subjects on their chest X‐rays, pulmonary function tests, and sputum cytology performed elsewhere.

These findings are compared to those of other shipyards, and support the hypothesis that the biological effects of asbestos exposure are generally mild in Hawaii.
Hospital‐based, academically affiliated occupational medicine clinics
Authors: Rosenstock Linda
Published: April 2007

An increasing number of clinics that provide diagnostic occupational medical services is being established in academically affiliated hospitals. In addition to the clinical services provided, training and research activities are a prominent feature of many of these clinics. Twenty‐five clinics of this type have been identified and are listed geographically.
Mechanisms for modification of bromobenzene hepatotoxicity by coadministered toluene and chlorobenzene
Authors: Koizumi Akio , Sadamoto Tetsuo , Naganuma Hiroshi , Ikeda Masayuki
Published: April 2007

Hepatotoxicity of bromobenzene (2 mmole/kg) in combination with toluene or chloro‐benzene (4 mmole/kg each) were studied in vivo on the basis of GPT elevation and histological examinations. Both toluene and chlorobenzene suppressed bromobenzene hepatotoxicity 24 hr after the treatment, and chlorobenzene dramatically potentiated the toxicity at 48 hr. The glutathione level became lower at 12 hr and recovered at 24 hr when bromobenzene was given alone. The recovery delayed until 48 hr when chlorobenzene was coadministered. In experiments in vitro with microsomes from phenobarbital‐pretreated rats, both toluene and chlorobenzene at 0.6 mM inhibited p‐bromophenol formation noncompetitively but had no effect on o‐isomer formation. Multiple factors may determine overall hepatotoxicity in combined exposure; bromobenzene hepatotoxicity will be suppressed in the early phase owing to metabolic inhibition of 3,4‐epoxidation, but potentiated later because of delayed recovery in the glutathione level. A time‐saving yet reliable assay system with an ECD‐gas chromatograph was developed for bromobenzene metabolism study.
Survey of reproductive hazards among oil, chemical, and atomic workers exposed to halogenated hydrocarbons
Authors: Savitz David A. , Harley Barbara , Krekel Sylvia , Marshall Julie , Bondy Jessica , Orleans Miriam
Published: April 2007

Several halogenated hydrocarbons are suspected of causing adverse reproductive effects. Because of such concerns, the Oil, Chemical, and Atomic Workers International Union surveyed the reproductive histories of two groups of workers. One group worked at plants engaged in the production or use of halogenated hydrocarbons (exposed) whereas the others had no such opportunity for exposure (nonexposed). Although a low response rate precludes firm conclusions, the 1,280 completed questionnaires provide useful data for generating hypotheses in this developing field of interest. A history of diagnosed cancer was reported more frequently among exposed workers. The infant mortality rate was also significantly elevated among the offspring of exposed workers. No risk gradient was observed for episodes of infertility, fetal loss, congenital defects, or low‐birth‐weight offspring. Concerns with nonresponse, exposure characterization, possible confounding factors, and limited statistical power are addressed. The results provide further suggestions which help to direct studies of occupational reproductive risks.
A proportionate mortality analysis of California agricultural workers, 1978–1979
Authors: Stubbs Harrison A. , Harris John , Spear Robert C.
Published: April 2007

There are few published reports of epidemiologic studies of the risks of agricultural work. Members of this occupational group have been of special concern because of their exposure to pesticides, some of which are mutagens and animal carcinogens. A previous proportionate mortality study of California agricultural workers was based on deaths recorded among white males of this occupational group during 1959–1961. We have conducted a proportionate mortality analysis of all deaths recorded during 1978–1979 among California farm workers and farm owner/managers. In general, the findings of our study are consistent with those of the previous study. For farm workers, we found proportionate mortality ratios (PMRs) which were consistently elevated for all race and sex categories (in which there were 6 or more decedents) for deaths due to motor vehicle accidents, all respiratory disease, and all infective and parasitic diseases. The PMRs for the former three causes of death were also found to be elevated across several race and sex categories for farm owner/managers. We also found a significant and consistent deficit of deaths among farm workers and farm owner/managers due to arteriosclerotic heart disease. The proportionate cancer mortality ratios (PCMRs) for cancer of the stomach and cancer of other lympahtic tissue were elevated, although not necessarily statistically significantly, for several race and sex categories among farm workers and farm owner/managers. The PCMR for cancer of the cervix was statistically significant for white female farmworkers.
Pneumoconiosis associated with exposure to glass and abrasive particles
Authors: Brody Julia , Miller Albert , Langer Arthur M.
Published: April 2007

A patient with a history of decorating glass fixtures by means of abrasive etching presented with a disease characterized by diffuse infiltrates on chest roentgenogram and restriction and diffusion impairment on pulmonary function testing. Mineralogic analysis of biopsied pulmonary lesions showed particles consistent in composition to the glasses etched and abrasives used. The former particles were noncrystalline. Silicate mineral phases were identified as well, these displaying crystalline properties. Previous studies of workers exposed to abrasives, ie, silicon carbide and emery (as a form of corundum) suggest slight pneumoconiotic risk exists; this is also the case for workers exposed to forms of industrially made glass. The question is raised as to whether there exists, in this present case, an etiological association between exposure to respirable glassy particles and the development of pulmonary scarring.
An alternative method for purification of a major thaumatin‐like grape protein (VVTL1) responsible for haze formation in white wine
Authors: Muhlack R. A. , Waters E. J. , Lim A. , O'Neill B. K. , Colby C. B.
Published: April 2007

A new laboratory‐based method for obtaining gram quantities of a principal heat‐unstable thaumatin‐like protein (VVTL1), in wine is presented. Separation and purification from grape juice was achieved by cation exchange and ultra‐filtration. Purity was confirmed by HPLC, sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE), gel permeation chromatography (GPC) and high‐sensitivity amino acid analysis. This alternative method is more rapid and compact and can efficiently produce much larger quantities (>100×) than the current laboratory technique. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
The small dispersion limit of the Korteweg‐de Vries equation. I
Authors: Lax Peter D. , David Levermore C.
Published: April 2007

In Part I the scattering transform method is used to study the weak limit of solutions to the initial value problem for the Korteweg‐deVries (KdV) equation as the dispersion tends to zero. In that limit the associated Schrödinger operator becomes semiclassical, so the exact scattering data is replaced by its corresponding WKB expressions. Only nonpositive initial data are considered; in that case the limiting reflection coefficient vanishes. The explicit solution of Kay and Moses for the reflectionless inverse transform is then analyzed, and the weak limit, valid for all time, is characterized by a quadratic minimum problem with constraints. This minimum problem is reduced to a Riemann‐Hilbert problem in function theory.

In Parts II and III we use function theoretical methods to solve the Riemann‐Hilbert problem in terms of solutions to an auxiliary initial value problem.

The weak limit satisfies the KdV equation with the dispersive term dropped until its derivatives become infinite. Up to that time the weak limit is a strong L2‐limit. At later times the weak limit is locally described by Whitham's averaged equations or, more generally, by the equations found by Flaschka et al. using multiphase averaging. For large times, behavior of the weak limit is studied directly from the minimum problem.
On the “piano movers'” problem I. The case of a two‐dimensional rigid polygonal body moving amidst polygonal barriers
Authors: Schwartz Jacob T. , Sharir Micha
Published: April 2007

We present an algorithm that solves a two‐dimensional case of the following problem which arises in robotics: Given a body B, and a region bounded by a collection of “walls”, either find a continuous motion connecting two given positions and orientations of B during which B avoids collision with the walls, or else establish that no such motion exists. The algorithm is polynomial in the number of walls (O(n5) if n is the number of walls), but for typical wall configurations can run more efficiently. It is somewhat related to a technique outlined by Reif.
The nonlinear interaction of a laser beam with a plasma pellet
Authors: Bayliss Alvin , Kriegsmann Gregory A. , Morawetz Cathleen S.
Published: April 2007

A model is developed which simulates the interaction of a laser beam with a plasma. The model allows for a nonlinear dependence of the density on the amplitude of the electric field. Numerical results show that for strong nonlinearities time‐harmonic fields cannot be obtained. Instead pulses of electromagnetic energy (solitary waves) are formed inside the plasma and carry energy away from the plasma.
The small dispersion limit of the Korteweg‐de Vries equation. III
Authors: Lax Peter D. , David Levermore C.
Published: April 2007

In Parts I and II we have derived explicit formulas for the distribution limit u of the solution of the KdV equation as the coefficient of uxxx tends to zero. This formula contains n parameters β1, …, βn whose values, as well as whose number, depends on x and t. In Section 4 we have shown that for t<tb, n=1, and the value of β, was determined. In Section 5 we have shown that the parameters βi satisfy a nonlinear system of partial differential equations.

In Part III, Section 6 we show that for t large, n=3, and we determine the asymptotic behavior of β1, β2, β3, and of u and u2, for t large. The explicit formulas show that u and u2 are O(t−1) and O(t‐2) respectively (see formulas (6.2) and (6.24)).

In Section 7 we study initial data whose value tends to zero as x→+∞, and to ‐1 as x→−∞. If one accepts some plausible guesses about the behavior of solutions with such initial data, we derive an explicit formula for the solution and determine the large scale asymptotic behavior of the solution:
equation image
.

The function s(ζ) is expressible in terms of complete elliptic integrals; a similar formula is derived for U2.

In Section 8 we indicate how to extend the treatment of this series of papers to multihumped (but still negative) initial data.
A particle limit for the wave equation with a variable wave speed
Authors: Hagedorn George A.
Published: April 2007

We study short wavelength solutions to the n‐dimensional wave equation utt =(c(x))2Δu. We prove that the propagation of certain spatially localized pulses is determined by a time dependent analogue of geometrical optics up to an error whose energy tends to zero in the zero wavelength limit. Our method is very explicit, and no difficulties are incurred as the pulses propagate through caustics. Our goal is to study the physical question of where the energy propagates, rather than the more mathematical question of the propagation of singularities which has been studied in Fourier integral operators.
Determining conductivity by boundary measurements
Authors: Kohn Robert , Vogelius Michael
Published: April 2007

In [2], A. P. Caldéron posed the following question: can one determine the heat conductivity of an object from static temperature and heat flux measurements at the boundary? We show that such measurements uniquely determine the conductivity and all of its derivatives at the boundary.
Translation representations for automorphic solutions of the wave equation in non‐euclidean spaces. I
Authors: Lax Peter D. , Phillips Ralph S.
Published: April 2007

This paper deals with the spectral theory of the Laplace‐Beltrami operator Δ acting on automorphic functions in n‐dimensional hyperbolic space Hn. We study discrete subgroups Γ which have a fundamental polyhedron F with a finite number of sides and infinite volume. Concerning these we have shown previously that the spectrum of Δ contains at most a finite number of point eigenvalues in [‐(1/2(n ‐ 1))2, 0], and none less than (1/2(n ‐1))2. Here we prove that the spectrum of Δ is absolutely continuous and of infinite multiplicity in (‐∞, ‐(1/2(n ‐ 1))2). Our approach uses the non‐Euclidean wave equation introduced by Faddeev and Pavlov,

Energy EF is defined as (ut, ut)‐(u, Lu), where the bracket is the L2 scalar product over a fundamental polyhedron with respect to the invariant volume of the hyperbolic metric. Energy is conserved under the group of operator U(t) relating initial data to data at time t. We construct two isometric representations of the space of automorphic data by L2(R, N) which transmute the action of U(t) into translation. These representations are given explicitly in terms of integrals of the data over horospheres. In Part II we shall show the completeness of these representations.

utt‐Lu = 0, L = Δ + (1/2(n ‐ 1))2.
Convergence of a large time step generalization of Godunov's method for conservation laws
Authors: Leveque Randall J.
Published: April 2007

A natural generalization of Godunov's method for Courant numbers larger than 1 is obtained by handling interactions between neighboring Riemann problems linearly, i.e., by allowing waves to pass through one another with no change in strength or speed. This method is well defined for arbitrarily large Courant numbers and can be written in conservation form. It follows that if a sequence of approximations converges to a limit u(x,t) as the mesh is refined, then u is a weak solution to the system of conservation laws.

For scalar problems the method is total variation diminishing and every sequence contains a convergent subsequence. It is conjectured that in fact every sequence converges to the (unique) entropy solution provided the correct entropy solution is used for each Riemann problem.

If the true Riemann solutions are replaced by approximate Riemann solutions which are consistent with the conservation law, then the above convergence results for general systems continue to hold.
On the Piano Movers' problem: IV. Various decomposable two‐dimensional motion‐planning problems
Authors: Sharir Micha , Ariel‐Sheffi Elka
Published: April 2007

Various special motion‐planning problems involving arbitrarily many degrees of freedom are shown to admit relatively simple solutions by techniques based on the connectivity graph approach described by Schwartz and Sharir. The solutions exploit the particularly simple configuration space structure of the robot systems considered. A typical problem is that of planning motions for a 2‐dimensional robot system consisting of several arms all jointed at one common endpoint and free to rotate past each other. The algorithm given for solving this problem runs in time O(nk+4), where k is the number of arms.
The inversion problem and applications of the generalized radon transform
Authors: Beylkin Gregory
Published: April 2007

We prove that under certain conditions the inversion problem for the generalized Radon transform reduces to solving a Fredholm integral equation and we obtain the asymptotic expansion of the symbol of the integral operator in this equation.

We consider applications of the generalized Radon transform to partial differential equations with variable coefficients and provide a solution to the inversion problem for the attenuated and exponential Radon transforms.
Translation representations for automorphic solutions of the wave equation in non‐euclidean spaces. II
Authors: Lax Peter D. , Phillips Ralph S.
Published: April 2007

In this part we prove that the translation representation defined in Part I for the non‐Euclidean wave equation is complete. We show how one can derive from this translation representation a spectral representation for the Laplace‐Beltrami operator over geometrically finite fundamental polyhedra with infinite volume, without the use of Eisenstein series.
On the piano movers' problem: V. The case of a rod moving in three‐dimensional space amidst polyhedral obstacles
Authors: Schwartz Jacob T. , Sharir Micha
Published: April 2007

This paper, a fifth in a series, solves some additional 3‐D special cases of the „piano movers”︁ problem, which arises in robotics. The main problem solved in this paper is that of planning the motion of a rod moving amidst polyhedral obstacles. We present polynomial‐time motion‐planning algorithms for this case, using the connectivity‐graph technique described in the preceding papers. We also study certain more general polyhedral problems, which arise in the motion planning problem considered here but have application to other similar problems. Application of these techniques to the problem of planning the motion of a general polyhedral body moving in 3‐space amidst polyhedral obstacles is also described.
On the essential spectrum of ideal magnetohydrodynamics. Dedicated to harold grad on the occasion of his sixtieth birthday
Authors: Hameiri Eliezer
Published: April 2007

The essential spectrum of magnetohydrodynamics (MHD) is shown to arise from waves propagating one‐dimensionally along magnetic field lines. Different polarizations of these waves give rise to the “Alfven” and “ballooning” spectra. The essential spectrum of an axisymmetric equilibrium when a single azimuthal mode number is considered consists of the Alfven spectrum only, while the ballooning modes appear as intervals of accumulation of discrete eigenvalues with different mode numbers. We derive some necessary and one sufficient conditions for stability and show some examples where the criteria coincide to yield a simple condition for stability.
Translation representations for automorphic solutions of the wave equation in non‐euclidean spaces. III
Authors: Lax Peter D. , Phillips Ralph S.
Published: April 2007

In Part III we show that the translation representations defined in Part I, and shown to be complete in Part II, are incoming and outgoing in the sense of propagation of signals along rays. We give a new proof of the absolute continuity of the spectrum below ‐¼n2, and point out its implications for local energy decay. We give a new proof of completeness in dimensions 2 and 3 when energy is positive. Finally, we define and prove completeness of the translation representations when the metric is perturbed on a compact set.
Existence of multiple periodic orbits on star‐shaped hamiltonian surfaces
Authors: Berestycki Henri , Lasry Jean‐Michel , Mancini Giovanni , Ruf Bernhard
Published: April 2007

Consider the Hamiltonian system (HS) i = 1, …, N. Here, H ϵ C2(ℝ2N, ℝ). In this paper, we investigate the existence of periodic orbits of (HS) on a given energy surface Σ = {z ϵ ℝ2N; H(z) = c} (c > o is a constant). The surface Σ is required to verify certain geometric assumptions: Σ bounds a star‐shaped compact region ℛ and αℰ ⊂ ℛ ⊂ βℰ for some ellipsoid ℰ ⊂ ℝ2N, o < α < β. We exhibit a constant δ > O (depending in an explicit fashion on the lengths of the main axes of ℰ and one other geometrical parameter of Σ) such that if furthermore β2/α2 < 1 + δ, then (HS) has at least N distinct geometric orbits on Σ. This result is shown to extend and unify several earlier works on this subject (among them works by Weinstein, Rabinowitz, Ekeland‐Lasry and Ekeland). In proving this result we construct index theories for an S1 ‐action, from which we derive abstract critical point theorems for S1 ‐invariant functionals. We also derive an estimate for the minimal period of solutions to differential equatious.
A new approach to queer differential equations
Authors: Laurence Peter , Stredulinsky E. W.
Published: April 2007

We study the variational problem magnified image Where Ψ* is the increasing rearrangement of Ψ. An approximate problem is introduced which involves a variational problem with n free boundaries (n → ∞). Various estimates are established. In particular, when Ω is convex we show that the solution to the approximate problem is superharmonic and has bounded gradient.
Interfaces with a corner point in one‐dimensional porous medium flow
Authors: Aronson D. G. , Caffarelli L. A. , Vazquez J. L.
Published: April 2007

We prove that for a large class of initial distributions the solutions of the initial value problem for the one‐dimensional porous medium equation have interfaces which start to move abruptly after a positive waiting time. This happens, for example, if the initial pressure is o(|x|2) as x → 0. We also give sufficient conditions for the smoothness of the interface which improve previous results.