bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquired intolerance to organic solvents and results of vestibular testing
Authors: Gyntelberg Finn , Vesterhauge Søren , Fog Pernille , Isager Henrik , Zillstorff Kaj
Published: April 2007

Among 160 consecutive patients referred to the Clinic of Occupational Medicine, Rigshospitalet, for symptoms connected with exposure to organic solvents, 20 exhibited symptoms of acquired intolerance to minor amounts of organic solvents. Later, an additional 30 consecutive patients with symptoms of acquired intolerance were included, yielding a total of 43 men and 7 women. The characteristics of the clinical syndrome described are complaints of dizziness, nausea, and weakness after exposure to minimal solvent vapor concentrations. After having tolerated long‐term occupational exposure to moderate or high air concentrations of various organic solvents, the patients became intolerant within a short period of time. Since dizziness was a frequent complaint, we tried to obtain a measure of the patients' complaints using vestibular tests. As a diagnostic test the combined vestibular tests had a sensitivity of 0.55 and a specificity of 0.87. No differences between patients with and without intolerance could be detected by the vestibular tests used. We conclude that acquired intolerance to organic solvents is a new but characteristic and easily recognizable syndrome, often with severe consequences for the patient's working ability.
Nasal cancer and occupation in Sweden, 1961–1979
Authors: Malker Hans S. R. , McLaughlin Joseph K. , Blott William J. , Weiner Jan A. , Malker Birgitta K. , Ericcson Jan L. E. , Stone B. J
Published: April 2007

Using national population–based registries which link cancer incidence (1961–1979) with 1960 census data on industry and occupation for all employed individuals in Sweden, a systematic assessment was made of nasal cancer (ICD 7th Rev. 160) with special reference to occurrence in manufacturing industries and craftsman–tradesman occupations. Data are presented for three histologic categories: adenocarcinoma, squamous cell carcinoma, and other histologic types. The highest risks (18–fold) were observed for adenocarcinoma among men employed in furniture making. Elevated risks were also observed for textile workers of both sexes. The findings are generally consistent with previous reports from other countries and help clarify the role of occupation in the origins of nasal cancer.
Reproductive hazards in the workplace: A case study of women firefighters
Authors: Evanoff Bradley A. , Rosenstock Linda
Published: April 2007

Recent attention has focused on the difficulties of providing equal employment opportunities for women while ensuring reproductive health in the workplace. This paper examines the potential hazards faced by pregnant firefighters and recommends a policy that seeks a reasonable accommodation between employment and fetal and maternal health. The potential hazards faced by firefighters include physical exertion, hyperthermia, and exposure to carbon monoxide and other toxic gases. The ideal policy option for improving reproductive health is to make the workplace safe for all employees. Where this cannot be accomplished and a unique reproductive hazard exists to women during pregnancy, temporary positions should be found that remove the pregnant woman from the hazard while allowing her to continue work.
Mortality in police and firefighters in New Jersey
Authors: Feuer Elizabeth , Rosenman Kenneth
Published: April 2007

A proportionate mortality study of police and firefighters in New Jersey was conducted using the records of a comprehensive retirement system. Three reference populations were used: (1) U.S. general population, (2) New Jersey general population, and (3) police as a reference group for the firefighters. Overall neither group differed from the New Jersey male population in the cause of death. Analyses by latency showed an increase in skin cancer and cirrhosis in firefighters and cirrhosis in police. With increased time from first employment, an inverse association was found between heart disease and time of first exposure. This was reflected in statistically significant increased proportionate mortality rates (PMR) for arteriosclerotic heart disease (ASHD) (ICD 410–414) for both working police (PMR = 1.15) and firefighters (PMR = 1.2). Retired police and firefighters had PMRs of 0.96 and 0.98, respectively. Firefighters had a significant increase in nonmalignant respiratory disease (PMR = 1.98) and leukemia (PMR = 2.76) when the police were used as a reference group. Potential causes of the above findings are discussed.
Peripheral eosinophilia and respiratory symptoms in rubber injection press operators: A case‐control study
Authors: Thomas Richard J. , Bascom Rebecca , Yang William N. , Fisher John F. , Baser Michael E. , Greenhut Janet , Baker John H.
Published: April 2007

To evaluate a suspected association between an outbreak of acute respiratory illness and eosinophilia and employment as a rubber worker, we performed a retrospective review of medical records of rubber workers employed from September 1983 to July 1984 in a plant housing a thermoinjection process. Twenty‐five workers met the case definition of a respiratory illness requiring a physician visit. The predominant respiratory illness was acute in onset with cough, chest tightness, and dyspnea. Peripheral eosinophilia, up to 40% of white blood cells in a peripheral smear, was seen in 10 of 18 (56%) cases. Twenty‐one of 25 white males with respiratory symptoms were employed in the thermoinjection process (odds ratio = 22, p < .001). Smoking and employment in this process contributed independently to an increased risk of being a case as determined by a logistic regression analysis. Return to the plant building caused recurrence of symptoms in most cases, and these workers have been transferred or left the company. We conclude that a strong previously unrecognized association exists between employment in this neoprene rubber thermoinjection process and the development of an acute respiratory illness.
Airborne particles, their use in the respiratory system to measure air flow, function, and clearance
Authors: Nelson Norton , Altshuler Bernard , Palmes Edward D. , Albert Roy E. , Lippmann Morton , Schlesinger Richard
Published: April 2007

Nonhygroscopic monodisperse particles can be used to estimate airway dimensions within chosen regions of the respiratory tract. These dimensions correspond well with those measured in inflation‐fixed lungs.

The dispersion of a bolus of airborne particles on inhalation and exhalation is very sensitive to the dimensions of the airways through which the bolus passes, yielding indices of dispersion that provide sensitive indicators of changes in airway dimensions, eg, with smoking.

The rates of clearance of particles from the lungs are determined using gamma‐labelled particles whose lung retention is determined by external measurements. There are major differences between the deep lung and the ciliated airways. Changes in clearance rates are caused by disease or inhaled intoxicants such as cigarette smoke.

At lower levels of irritant exposure, an acceleration of clearance rate is observed, while higher doses and longer periods of exposure produce decreased rates.

It is suggested that aerosol techniques may have useful clinical applications; approaches are suggested for such applications.
Mortality among ferrous foundry workers
Authors: Silverstein Michael , Maizlish Neil , Park Robert , Silverstein Barbara , Brodsky Lynda , Mirer Franklin
Published: April 2007

Mortality analyses were carried out for 278 male hourly workers who were employed for at least 10 years at a gray iron foundry and who died between January 1, 1970 and December 31, 1981. Statistically significant excess proportional mortality due to nonmalignant respiratory disease (SPMR = 177), lung cancer (SPMR = 148), and leukemia (SPMR = 284) was found among the 221 white males. Among nonwhite males there was a significant excess in proportional mortality due to circulatory diseases (SPMR = 143). White males in the Finishing classification experienced a significant excess of proportional mortality due to nonmalignant respiratory disease (SPMR = 279) and lung cancer (SPMR = 179). White males in the Core Room classification experienced an excess of proportional mortality due to nonmalignant respiratory disease (SPMR = 321). Case‐control studies demonstrated a significant association between nonmalignant respiratory disease and the Finishing classification after controlling for the effects of age, prior occupations in coal mining or foundries, and smoking. A positive but nonsignificant association between lung cancer and Finishing was also found after controlling for age, prior work history, and smoking in case control studies.
Chromium content of organs of chromate workers with lung cancer
Authors: Kishi Reiko , Tarumi Takashi , Uchino Eiji , Miyake Hirotsugu
Published: April 2007

The content of chromium was measured in organs of six chromate workers who had worked in a chromate chemical manufacturing plant, had been exposed to a considerable amount of chromiun for over 10 years, and had died of lung cancer. The chromium in the lungs of workers averaged 51.5 μg/g (range 24.8–210 μg/g), while levels in the lungs of non‐exposed controls were 0.07–1.01 μg/g. Organs other than the lungs of the workers also had more chromium than those of the controls. Moreover, it was apparent that the metal remained in the lungs long after exposure to chromate had ceased.
A cohort mortality study among cobalt and sodium workers in an electrochemical plant
Authors: Mur J. M. , Moulin J. J. , Charruyer‐Seinerra M. P. , Lafitte J.
Published: April 2007

We have studied the mortality between 1950 and 1980 of a cohort of 1,143 workers in an electrochemical plant producing cobalt and sodium. The mortality of the whole cohort is significantly lower than in the French population for all causes of death (SMR = 0.77), and especially for deaths from circulatory system diseases (SMR = 0.59). However, among cobalt production workers, there is a relative over‐mortality, especially from lung cancers (SMR = 4.66, 4 cases). The relationship between cobalt production and lung cancer mortality was supported by a case‐control study nested in the cohort study. The authenticity of the occupational origin of this risk could not be established due to the low number of cases and because the role of tobacco consumption could not be taken into account. Other studies should be carried out in plants producing or using cobalt.
Cancer and other causes of death among wisconsin farmers
Authors: Saftlas Audrey F. , Blair Aaron , Cantor Kenneth P. , Hanrahan Larry , Anderson Henry A.
Published: April 2007

Computerized mortality listings for Wisconsin for 1968‐1976 were used in proportional mortality ratio (PMR) and proportional cancer mortality ratio (PCMR) analyses to evaluate mortality patterns among Wisconsin farmers. Examination of PCMR trends by per capita county level of agricultural production was limited to the youngest birth cohort (1905‐1958) and cancer sites associated with farming exposures in either the present or previous analyses. Among all Wisconsin farmers, significantly decreased PMRs were seen for tobacco‐ and alcohol‐related causes of death, while excesses occurred for accidential causes, asthma, and cancer of the stomach, prostate, eye, and lymphatic and hematopoietic systems. Elevated PCMR's for leukemia and all lymphopoietic cancer and cancers of the stomach, rectum, eye occurred in farmers born 1905‐1958, while deficits were observed for cancer of the pancreas and the category, “all other cancers.” Increases in PCMR's with level of various agricultural activities were largely associated with cancers of other lymphatic tissue (2/3 of which were multiple myeloma) and the rectum. Certain agricultural exposures were also positively associated with deaths due to cancers of the prostate, brain, lymphosarcoma and reticulosarcoma, and all lymphopoietic cancers. No positive PCMR gradients were observed for leukemia and malignancies of the stomach and eye. Modern chemical practices in farming may account for some of the patterns noted.
Experimental and clinical studies on the reproductive toxicology of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin
Authors: Silbergeld Ellen K. , Mattison Donald R.
Published: April 2007

The reproductive toxicology of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) has been studied in animal models and in human populations. In animals, TCDD has a range of toxic effects on organs of the reproductive system in males and females, on hormone biochemistry, and on embryo‐fetal development. These effects may involve in part an identified intracellular TCDD receptor and its association with the induction of microsomal cytochrome P‐450‐dependent monooxygenases in many organs. TCDD treatment increases activity of monooxygenase enzyme in liver and gonads of treated animals, but unlike other polycyclic aromatic hydrocarbons that are monooxygenase inducers, TCDD is not cytotoxic to any population of oocytes in the mature female mouse. Epidemiological studies of TCDD reproductive toxicity have been limited in design. There are some reports of adverse effects in the Seveso population and in children born to American veterans presumed to have been exposed to TCDD in Agent Orange during the Vietnam war. Occupational cohorts have not been found to show such paternally mediated effects of TCDD exposure.
Semiconductor manufacturing: An introduction to processes and hazards
Authors: Wald Peter H. , Jones Jeffrey R.
Published: April 2007

Recent studies suggest that semiconductor workers have an increased incidence of work‐related illness. Semiconductor manufacturing is a chemically intensive industry involving many potentially hazardous operations. As this industry moves into new geographic areas, health care professionals will be asked to evaluate medical or workplace conditions associated with unfamiliar and complex production processes. This paper provides an overview of semiconductor manufacturing processes for these health practitioners. Each step of device fabrication is detailed with its attendant chemical and physical hazards. Broader concepts of industrial control technology, clean room ventilation, and ergonomics are explained. The hazards are tabulated to allow rapid assessment of the risks inherent to each processing step. References have been chosen to guide the reader to more indepth information.
An asbestos hazard in the reprocessed textile industry
Authors: Quinn M. M. , Kriebel D. , Buiatti E. , Paci E. , Sini S. , Vannucchi G. , Zappa M.
Published: April 2007

Epidemiologic studies have identified an excess risk of lung cancer and mesothelioma among workers in the reprocessed textile industry in Prato, Italy. These studies suggested that there may have been asbestos hazard in this industry although exposure was not known to exist. An industrial hygiene investigation was conducted to determine whether there was previous or current asbestos exposure in the industry. Walk‐through surveys, environmental sampling, process documentation, and management and worker interviews were conducted in 13 textile reprocessing establishments. Polypropylene bags that once contained asbestos were found in 2 of the 13. Asbestos bags were cut open and used to cover bales of rags which were then distributed throughout the world. Workers were exposed to asbestos while handling the bags which were contaminated with chrysotile, amosite, and crocidolite. Additional sources of asbestos exposure that may have existed in the past in the industry are also discussed.
Relationship between external and internal parameters of exposure to manganese in workers from a manganese oxide and salt producing plant
Authors: Roels Harry , Lauwerys Robert , Genet Pierre , Sarhan Mohammad Jawad , de Fays Michèle , Hanotiau Isabelle , Buchet Jean‐Pierre
Published: April 2007

In a plant producing manganese (Mn) oxides and salts, 11 different workplaces were identified. The current exposure to airborne Mn (total dust, personal sampling, n = 80) varied from 0.07 to 8.61 mg/m. The geometric mean and median values amounted approximately to 1 mg/m3 and the 95th percentile was 3.30 mg/m3. The concentration of Mn in blood (Mn‐B) in a group of 141 Mn‐exposed male workers ranged from 0.10–3.59 μg/100 ml compared to 0.04–1.31 μg/100 ml in a group of 104 control subjects. The ranges of the concentrations of Mn in urine (Mn‐U) were 0.06–140.6 and 0.01–5.04 μg/g creatinine for the exposed and control groups, respectively. The average level of Mn‐B in the Mn group was more than twice as high as in the control group (arithmetic mean, 1.36 vs 0.57 μg/100 ml) and that of Mn‐U was ten times higher in the Mn group (geometric mean, 1.56 vs 0.15 μg/g creatinine). The Mn‐B level did not change significantly after 8 h of Mn exposure, whereas the Mn‐U level dropped rapidly when exposure ceased (half‐life less than 30 h).

On an individual basis, neither Mn‐B nor Mn‐U correlated with the current levels of Mn‐air or duration of Mn exposure. There was also no relationship between Mn‐B and Mn‐U. On a group basis, there was no correlation between the mean Mn‐B levels and the current levels of Mn‐air at each workplace; however, a slight but significant correlation (r = 0.62, p < 0.05) was found between the geometric mean of Mn‐U of each subgroup (n = 11) and the current level of Mn‐air at their corresponding workplaces. On a group basis (n = 6), Mn‐U did not correlate with the estimation of past integrated exposure of the workers, while group means of Mn‐B significantly correlated with past integrated exposure. These results indicate that the individual evaluation of the Mn exposure intensity remains difficult on the basis of Mn‐B and Mn‐U. On a group basis however, Mn‐U appears to reflect very recent exposure, while Mn‐B is to some extent a reflection of the body burden of Mn.
Death certificate‐based occupational mortality surveillance in the united states
Authors: Dubrow Robert , Sestito John P. , Lalich Nina R. , Burnett Carol A. , Salg Joyce A.
Published: April 2007

Surveillance of cause‐specific mortality patterns by occupation and industry through the use of death certificate records is a simple and relatively inexpensive approach to the generation of leads as to potential occupational disease problems. Researchers from the National Institute for Occupational Safety and Health (NIOSH) have been working with the National Center for Health Statistics, other federal agencies, and state health departments on a number of programs to foster the development of standardized, routine coding of occupation and industry entries on death certificates by state health departments. Thirty‐one states and the District of Columbia are now doing such coding. These data are being analyzed currently by investigators at NIOSH and at individual state health departments for the purpose of hypothesis generation on occupation–disease relationships. The proportionate mortality ratio method is the predominant method being used, as appropriate denominator data are not generally available. This type of surveillance is particularly useful for the study of occupation and industry groups for which it is difficult to assemble cohorts, such as groups that are predominantly non‐union and in small workplaces. Limitations of this surveillance include its inappropriateness for monitoring those occupational diseases which are not often fatal, and the limited scope and accuracy of death certificate information.
Historical perspective on asbestos: Policies and protective measures in world war ii shipbuilding
Authors: Corn Jacqueline Karnell , Starr Jennifer
Published: April 2007

Current public health consequences of poorly controlled utilization of asbestos in the past can be traced back, in part, to decisions made 45 or more years ago. This paper focuses on the extensive use of asbestos as a fireproofing and insulating material in shipbuilding in the 1940s, when World War II industrial expansion brought about a hitherto unprecedented rise in the amount of asbestos utilized. Twenty years after World War II, asbestos diseases began to manifest themselves, affecting thousands of shipyard workers as well as other workers who had been exposed in the 1940s and during the postwar period.

By scrutinizing past actions, the paper argues that social forces, as well as science and technology, affect the setting of priorities and the determination of policy regarding needed but hazardous materials.
Two‐Year Inhalation Toxicity Study of Petroleum Coke in Rats and Monkeys
Authors: Klonne Dennis R. , Burns John M. , Halder Clive A. , Holdsworth Charles E. , Ulrich Charles E.
Published: April 2007

Sprague‐Dawley rats and Cynomolgus monkeys were exposed to dust aerosol concentrations (0, 10.2, and 30.7 mg/m3) of micronized delayed process petroleum coke for 6 hr/day, 5 days/week over 2 years. With the exception of pulmonary effects, particularly in the rats, no significant adverse treatment‐related effects were observed. Both dust‐exposed groups of both species exhibited a gray to black discoloration of the lung, an observation consistent with pulmonary deposition of the coke dust, as well as increased absolute and/or relative lung weight values. The pulmonary histopathology in the monkeys was limited to the deposition and phagocytosis of the test material by pulmonary macrophages. The rats also exhibited these responses, but with concomitant signs of chronic inflammation and focal areas of fibrosis, bronchiolization, sclerosis, squamous alveolar metaplasia, and keratin cyst formation. No difference in the mortality rate was observed between the control and exposed groups of rats. Lastly, no significant increases in chromosomal aberrations were observed in rodents of the 10.2 or 30.7 mg/m3 exposure groups when examined after 5 days, 12 months, and 22 months of exposure.
Statistical methods for describing developmental milestones with censored data: effects of birth weight status and sex in neonatal pigtailed macaques
Authors: Kroeker Rose , Sackett Gene , Reynolds Joel
Published: April 2007

Neurobehavioral tests are used to assess early neonatal behavioral functioning and detect effects of prenatal and perinatal events. However, common measurement and data collection methods create specific data features requiring thoughtful statistical analysis. Assessment response measurements are often ordinal scaled, not interval scaled; the magnitude of the physical response may not directly correlate with the underlying state of developmental maturity; and a subject's assessment record may be censored. Censoring occurs when the milestone is exhibited at the first test (left censoring), when the milestone is not exhibited before the end of the study (right censoring), or when the exact age of attaining the milestone is uncertain due to irregularly spaced test sessions or missing data (interval censoring). Such milestone data is best analyzed using survival analysis methods. Two methods are contrasted: the non‐parametric Kaplan–Meier estimator and the fully parametric interval censored regression. The methods represent the spectrum of survival analyses in terms of parametric assumptions, ability to handle simultaneous testing of multiple predictors, and accommodation of different types of censoring. Both methods were used to assess birth weight status and sex effects on 14 separate test items from assessments on 255 healthy pigtailed macaques. The methods gave almost identical results. Compared to the normal birth weight group, the low birth weight group had significantly delayed development on all but one test item. Within the low birth weight group, males had significantly delayed development for some responses relative to females. Am. J. Primatol. 69:1313–1324, 2007. © 2007 Wiley‐Liss, Inc.
Ueber die Blitzröhren und ihre Entstehung
Authors: Fiedler Karl Gustav
Published: April 2007

Mit wahrem Vergnügen lege ich meinen Lesern diese wohlgerathene mineralogisch‐physikalische Monographie eines Gegenstandes vor, welcher der Aufmerksamkeit der Physiker werth ist. Sie rührt von einem jungen Manne her, der den berühmten Lehrern Göttingens, welche ihn zu diesem Unternehmen ausgemuntert und es befördert haben, seinen Dank mit ihr darzubringen wünschte, und dieses auf eine desto ehrenvollere Art mir zu thun scheint, je befriedigender diese seine Arbeit ist. Dass die Blitzröhren zuerst in Deutschland, und zwar in der unter dem Namen der Senne bekannten Sandwüste Paderborns, von dem unweit derselben in dem Fürstenthum Lippe wohnenden Oekonomen, Herrn Hentzen, entdeckt, und durch ihn, als solche, im Jahr 1805 bekannt geworden sind, dürfte den mehrsten meiner Leser unbekannt seyn.
Bei einem Gewitter angeblich herabgefallner Phosphor
Authors: Gilbert
Published: April 2007

Was Herr Chaldni S. 274. seines an neuen und erwägungswerthen Ansichten reichen Aufsatzes von Schwefel anführt, der als Meteor herabgefallen seyn soll (womit man Ritter's Gedanken in diesen Annalen B. 2. S. 3. vergleiche), veranlasst mich, diese letzte Seite mit der Erzählung eines Falls auszufüllen, wo man in dem Dorfe Connewitz bei Leipzig dasselbe von Phosphor beobachtet zu haben glaubte. Im August 1814, an einem Dienstag, um 3 Uhr Nachmittags donnerte es zwei Mal sehr heftig und plötzlich; der zweite Schlag besonders dünkte den Einwohnern über ihren Köpfen zu entstehen, und gleich nach demselben fing es an zu hageln. Der Besitzer des Landhauses, welches am Eingange des Dorfs, wenn man von Leipzig kömmt, liegt, erzählte mir am folgenden Tage, seine Bedienung habe um 10 Uhr Abends in dem kleinen Hofe, vor der Thüre der Küche, etwas, wie ein schön leuchtendes Johanniswürmchen, erblickt, und es hineingenommen. Am andern Tage hatte es an der feuchten Stelle, wo es lag, einen Fleck von der Grösse eines Kirschkerns gezogen; von der Köchin in ihrer Schürze der Herrschaft gebracht, entzündete es sich und auf Papier, das von Kohlenstaub schwarz war, brannte es mit heller Flamme und weissem Qualm. Der Besitzer hatte die Güte mir das Papier und den Körper mitzubringen, von dem seine Hausgenossen glaubten, er sey mit dem gewaltigen Donnerschlage am vorigen Nachmittage herabgefallen. Es war ein 1/3 Zoll langes Stückchen eines dünnen Phosporstängelchens mit länglichem unregelmässigen Endbruche. An einen meteorischen Ursprung konnte ich bei dieser Gestaltung nicht glauben, wohl aber an einen Muthwillen irgend eines Unvorsichtigen. Einen ähnlichen Körper, hörte ich nacher, solle der Nachtwächter vor dem Thorweg der Schenke gesehen und in den Sand getreten, auch ein kleiner vom Herrn Kaufmann Kraft verschickter Junge gefunden und eingesteckt haben, das Ding habe aber in seiner Tasche angefangen zu brennen.
Surface properties of Reverse osmosis membrane
Authors: Yongyi Yao , Shiwei Guo , Yunxiang Zhang
Published: April 2007

The morphology and structure of the top surfaces of three commercially Reverse osmosis (RO) membranes (Vontron Eviro‐Tech) have been studied using SEM and AFM techniques. As a result, the unevenness of the surface of ULP21 membrane was the greatest and that of SW21 membrane was smooth. The more the roughness of the top surface of the RO membranes was, the larger the flux of the RO membranes was. Accordingly, the roughness of the top surface of RO membranes intensively affected on the performance of RO membrane. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Assessment of non‐response bias in a survey of residential magnetic field exposure in Taiwan
Authors: Li Chung‐Yi , Mezei Gabor , Sung Fung‐Chang , Silva Michael , Lee Pei‐Chen , Chen Pei‐Chun , Chen Li‐Mei
Published: April 2007

We assessed potential non‐response bias in obtaining information on residential extremely low‐frequency power frequency magnetic field (MF) in Taiwan. All households occupied by children aged less than 7 years in two study districts, one in an urban town and the other in a rural town, were visited and solicited for on‐site measurements in late 2003. The initial response rate was only 32% (33/104, urban) and 60% (61/101, rural). In the same season 1 year later, we performed a second survey of those who declined to be measured at the initial survey and successfully measured another 77 residences (50 and 27 for urban and rural districts, respectively). The two districts were selected mainly because the local public health officers were quite willing to assist the initial survey and to inform residents of the second survey. Except for meteorological conditions, the two surveys came up with very similar findings regarding residential characteristics and power facilities surrounding the houses. The mean residential MF for the urban residences was .121 and .140 micro‐Tesla (µT) (P = .620) for the two surveys. The corresponding figures for the rural residences were .119 and .115 µT (P = .802). Although limited in its scope, this study tends to indicate that measurement studies of residential MF are less likely to suffer from serious selection bias if sampling is confined within a small district where people have similar socioeconomic characteristics. Bioelectromagnetics 28:340–348, 2007. © 2007 Wiley‐Liss, Inc.
Sentinel node biopsy for breast cancer larger than 3 cm in diameter
Authors: Schüle J , Frisell J , Ingvar C , Bergkvist L
Published: April 2007

Background

Sentinel node biopsy (SNB) is a standard staging procedure in early breast cancer. Its suitability for larger tumours has been questioned. This study evaluated the reliability of SNB in women with invasive breast cancer larger than 3 cm in diameter who were clinically axillary node negative.

Methods

Some 109 women with a tumour larger than 3 cm on pathological analysis were identified from the Swedish prospective SNB database. They were included if a completion axillary clearance was planned, regardless of SNB results.

Results

The sentinel node detection rate was 103 (94·5 per cent) of 109. The overall false-negative rate was eight (13 per cent) of 64. Although a preoperative diagnosis of multifocal tumour was an exclusion criterion, 16 such cases were revealed on postoperative pathological examination. The false-negative rate in this subgroup was higher than that in women with a unifocal tumour (four (31 per cent) of 13 versus four (8 per cent) of 51; P = 0·012). No other significant predictors of a false-negative sentinel node biopsy were identified.

Conclusion

SNB is feasible in patients with unifocal breast tumours larger than 3 cm. When large tumour size coincides with multifocality, however, the false-negative rate seems to be increased and a completion axillary clearance should be considered even if the SNB is negative.
An Intermediate for the Clean Synthesis of Ionic Liquids: Isolation and Crystal Structure of 1,3‐Dimethylimidazolium Hydrogen Carbonate Monohydrate
Authors: Bridges Nicholas J. , Hines C. Corey , Smiglak Marcin , Rogers Robin D.
Published: April 2007

1,3‐Dimethylimidazolium‐2‐carboxylate and carbonic acid have been used to prepare a 1,3‐dimethylimidazolium hydrogen carbonate salt by means of a Krapcho reaction. The ability to form hydrogen carbonate azolium salts allows for them to be used as precursors for fast, efficient, environmentally benign, and halide‐free syntheses of many ionic liquids by a simple, acid–base reaction of virtually any acid (inorganic, organic, and organic noncarboxylic) with a pKa less than that of HCO3−. Additionally, the kinetics of this reaction can be accelerated by employing catalytic amounts of DMSO (a traditional Krapcho solvent used in decarboxylation reactions) to catalyze the decarboxylation. The crystal structure of 1,3‐dimethylimidazolium hydrogen carbonate monohydrate is the first example of an imidazolium‐based hydrogen carbonate salt. There is a strong 2D hydrogen‐bonded network with facially π‐stacked imidazolium cations located in the cavities created by this framework.
Determination of the enantiomeric excess of chiral carboxylic acids by 31P NMR with phosphorylated derivatizing agents from C2‐symmetrical diamines containing the (S)‐α‐phenylethyl group
Authors: Mastranzo Virginia M. , Quintero Leticia , de Parrodi Cecilia Anaya
Published: April 2007

The use of P(III) and P(V) organophosphorus derivatizing agents prepared from C2 symmetrical (1R,2R)‐ and (1S,2S)‐trans‐N,N′‐bis‐[(S)‐α‐phenylethyl]‐cyclohexane‐1,2‐diamines 1 and 2, as well as (1R,2R)‐ and (1S,2S)‐trans‐N,N′‐bis‐[(S)‐α‐phenylethyl]‐4‐cyclohexene‐1,2‐diamines 3 and 4 for the determination of enantiomeric composition of chiral carboxylic acids by 31P NMR, is described. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Enantioseparation of phenylglycinol in chiral‐modified zeolite HY: A molecular simulation study
Authors: Jirapongphan Siricharn S. , Warzywoda Juliusz , Budil David E. , Sacco Albert
Published: April 2007

A mechanism has been proposed for the separation of valinol enantiomers using a chiral‐modified zeolite HY (i.e., zeolite HY containing (+)‐(1R;2R)‐hydrobenzoin) Molecular modeling of chiral‐modified zeolite HY employed in enantioselective separation. Jirapongphan SS, Warzywoda J, Budil DE, Sacco A Jr. Chirality 2007; in press, which accurately predicted the experimentally measured enantioseparation. This methodology has been applied to predict the separation of an enantiomeric pair of phenylglycinol molecules (a precursor in the synthesis of HIV‐1 protease inhibitors) using the modified zeolite HY as a CSP. Phenylglycinol and valinol molecules are similar in terms of the presence of polar (i.e., amine and hydroxyl) groups. These functional groups are important in the proposed chiral discrimination. Supercage‐based docking simulations yielded an enantioselectivity of 1.3 with (+)‐(S)‐phenylglycinol molecule better retained in the zeolite. Also, the simulations predicted two binding modes that were the same as those in the valinol system. This suggests that specific structural features (i.e., number and type of polar groups), which generate the hypothesized binding modes, are required in an enantioseparation utilizing the chiral‐modified zeolite HY. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Generalizations of the neumann system a curve‐theoretical approach‐part I
Authors: Schilling R. J.
Published: April 2007

The following observation, due to E. Trubowitz, illustrates an intimate relationship between spectral theory and Hamiltonian mechanics in the presence of constraints. Let q(s) be a real periodic function such that the Hill operator, magnified image has only a finite number gR of simple eigenvalues. There exist gR + 1 periodic eigenfunctions x1,…, x and corresponding eigenvalues a1,…, a of L such that magnified image where yr = dxr/ds. The equations Lxr = arxr, r = 1,…,gR+1, make up the classical Neumann system, a system of harmonic oscillators constrained to the unit sphere.

H. Flaschka obtained similar results about the Neumann system from a more general point of view. His assumption, that there exists an operator of odd order that commutes with L, leads to algebraic curve theory by the method of Krichever and from there to the Neumann formulas above. The familiar Lax pairs, the constants of motion and the quadrics of the Neumann system emerge as consequences of the Riemann‐Roch theoreni. The existence of isospectral deformations of L, the Korteweg de‐Vries hierarchy of the soliton equations, underlies the complete integrability of the Neumann system. This paper extends Flaschka's techniques, replacing L by an operator of order n 2 2. Higher Neumann systems are defined in a way that leads naturally to interesting symplectic manifolds, Lax pairs and integrals of motion. C. Tomei, using scattering theory, obtained some of our n = 3 formulas.
Frames in the bargmann space of entire functions
Authors: Daubechies Ingrid , Grossmann A.
Published: April 2007

We look at the decomposition of arbitrary f in L2(R) in terms of the family of functions φmn(x) = π−1/4exp{ − 1/2imnab + i max − 1/2(x − nb)2}, with a, b > 0. We derive bounds and explicit formulas for the minimal expansion coefficients in the case where ab = 2π/N, N an integer ≧ 2. Transported to the Hilbert space F of entire functions introduced by V. Bargmann, these results are expressed as inequalities of the form

We conjecture that these inequalities remain true for all a, b such that ab < 2π.
Inverse boundary value problems at the boundary—continuous dependence
Authors: Sylvester John , Uhlmann Gunther
Published: April 2007

We use the methods of microlocal analysis to give a new proof of a theorem of Kohn and Vogelius, showing that the boundary values of a continuous isotropic conductivity can be recovered from voltage and current measurements at the boundary. Moreover, we prove sharp estimates to establish the continuous dependence of the boundary values of the conductivity on the voltage to current maps.
BETAS, a spectral code for three‐dimensional magnetohydrodynamic equilibrium and nonlinear stability calculations
Authors: Betancourt Octavio
Published: April 2007

A fully three‐dimensional spectral code has been developed and implemented. It computes three‐dimensional equilibria using the variational approach, by minimizing the potential energy subject to appropriate constraints. A second minimization, with an additional constraint, is used to examine the stability of solutions.

The magnetic field representation allows for non‐nested flux surfaces. Thus it can be used to study solutions with islands and variation of the potential energy with respect to topology changes.

A spectral representation in the toroidal and poloidal angles, coupled with a special choice of collocation points in the radial direction results in greatly enhanced resolution.

A fast iterative method was developed, with the number of iterations required for convergence independent of the mesh size. Residuals converge exponentially to the round‐off error, allowing the potential energy to be computed to the eight‐digit accuracy required for nonlinear stability analysis. A small amount of artificial viscosity may be needed for convergence in cases where low‐order resonances are present in the plasma region.

Numerical results show convergence to known axially symmetric equilibrium solutions, as well as close agreement with eigenvalue calculations in helically symmetric stellarator configurations. Solutions exhibiting island formations are found to have lower potential energy than that of the nearby nested case. Internal modes are found to localize inside the resonant surface, with the eigenfunction having sharp gradients at the resonant surface.
The interaction of nonlinear hyperbolic waves
Authors: Glimm James
Published: April 2007

Nonlinearities in wave equations lead to focusing and defocusing of solutions. Focusing causes sharply defined wave fronts. The interaction of such sharply defined wave fronts and more generally of nonlinear hyperbolic waves is of fundamental importance and includes such phenomena as Mach triple point formation, shock wave diffraction patterns and the study of Riemann problems in one and higher dimensions.

Recent progress in the study of nonlinear hyperbolic wave interactions has revealed a surprising range of new mathematical phenomena and structures. This mathematical theory should be useful in the design of improved computational algorithms and in part was motivated by such considerations. It is also of considerable interest for its own sake as new mathematical phenomena as well as in terms of the direct insight it provides into physical phenomena.

Within the subject matter and point of view adopted here, we have attempted to present a broad and, we hope, a representative account of recent progress.
Magnetic and drift surfaces in stellarators
Authors: Ng Kam‐Chuen
Published: April 2007

In this paper we study the structure of a stellarator field in toroidal geometry. A field line tracing code is developed to explore the structure of magnetic fields on the fine scale of the electron gyroradius pe, so as to explain anomalous electron transport. The magnetic field is modelled by a simple analytic representation with finite number of parameters, so that we can integrate the field lines to a high accuracy. In a typical Heliac field we find that (i) most of the magnetic surfaces are well behaved on the fine scale, even when there is no two‐dimensional symmetry and (ii) the width of an island, formed in the vicinity of a magnetic surface with rational rotational transform i = n/m, decays exponentially with m. Among those numerical studies, we have an example where the island width w is less than the electron gyroradius pe for m greater than 17. This demonstrates that higher‐order islands do not affect the electron transport.

Our numerical results indicate that the anomalous electron transport observed in experiments may be due to the presence of an ambipolar electrostatic potential Φ. To reconfirm this proposition we compute the guiding center orbits of electrons and estimate the island widths of the drift surfaces that are swept out. We find that with a small electric potential depending on toroidal and poloidal angles, the drift surface island width w is an order of magnitude larger than that without the electric potential and decays exponentially at a slower rate. Since the drift step size is of the order of the maximum of pe and w, the electron transport, which scales like the square of the step size, is enhanced when there is an electric potential.
Two new moving boundary problems for scalar conservation laws
Authors: Ross David Stewart
Published: April 2007

The application of the theory of scalar conservation laws to semiconductor device fabrication is described. This application is the source of a Stefan problem and another moving boundary problem for a class of such equations. The analogue of the Riemann problem for these problems is analyzed and solved. Conditions on the boundary values that characterize physically correct solutions are derived.
Huygen's principle on nonempty space‐times
Authors: Kovalyov Mikhail
Published: April 2007

Huygen's principle is considered on some nonempty space‐time manifolds. It is proved that if Huygen's principle holds in a space with spherically symmetric time‐independent metric, then the space must have constant curvature.
Ill‐posedness in three‐dimensional plastic flow
Authors: Schaeffer David G. , Pitman E. Bruce
Published: April 2007

This paper examines partial differential equations for frictional materials flowing via plastic yield, including the equations given by the Critical State Theory of Soil Mechanics. In particular, the material density is considered as a dependent variable. In previous work we demonstrated that two‐dimensional plastic flow may be ill posed due to an instability along two rays in Fourier transform space. In this paper, we show that in three dimensions the equations are linearly well posed provided all three strain rates are nonzero.
Orthonormal bases of compactly supported wavelets
Authors: Daubechies Ingrid
Published: April 2007

We construct orthonormal bases of compactly supported wavelets, with arbitrarily high regularity. The order of regularity increases linearly with the support width. We start by reviewing the concept of multiresolution analysis as well as several algorithms in vision decomposition and reconstruction. The construction then follows from a synthesis of these different approaches.
Compactness theorems for differential forms
Authors: Kichenassamy S.
Published: April 2007

We prove compactness properties of various sets of differential forms with bounds on their exterior derivatives. This gives simple proofs of the Federer‐Fleming result on normal currents and of „compensated compactness”︁ lemmas.
Hydrodynamics and large deviation for simple exclusion processes
Authors: Kipnis C. , Olla S. , Varadhan S. R. S.
Published: April 2007

We prove the hydrodynamical limit for weakly asymmetric simple exclusion processes. A large deviation property with respect to this limit is established for the symmetric case. We treat also the situation where a slow reaction (creation and annihilation of particles) is present.
Compactness methods in the theory of homogenization II: Equations in non‐divergence form
Authors: Avellaneda Marco , Lin Fang‐Hua
Published: April 2007

We prove C0, α, C1, α and C1, 1 a priori estimates for solutions of boundary value problems for elliptic operators with periodic coefficients of the form Σ,j=1ai j(x/ϵ)δ2/δxiδxj. The constants in these estimates are independent of the small parameter ϵ, and hence our results imply strengthened versions of the classical averaging theorems. These results generalize to a wide class of linear operators in non‐divergence form, including equations with lower‐order terms and nonuniformly oscillating coefficients, as well as to certain nonlinear problems, which we discuss in the last section.
Uniqueness failure for entropy solutions of hyperbolic systems of conservation laws
Authors: Sever Michael
Published: April 2007

We consider a nonlinear system of conservation laws, which is strictly hyperbolic, genuinely nonlinear in the large, equipped with a convex entropy function and global Riemann invariants. Nevertheless, for such a system for dimension five, it is shown that uniqueness of the similarity solution of a Riemann problem satisfying the entropy condition can fail.
An initial‐boundary value problem of physiological significance for equations of nerve conduction
Authors: Mascagni Michael
Published: April 2007

A model of nerve conduction that has gained wide acceptance in the biophysical community is that for the giant axon of the squid Loligo of Hodgkin and Huxley [5]. This nonlinear parabolic partial differential equation (PDE), when considered as part of a particular initial‐boundary value problem (IBVP), models the electrical activity of an axon under conditions found both in nature and in the laboratory. This IBVP for the Hodgkin‐Huxley equations is proved to be well posed in the sense of Hadamard [3], and a priori bounds on the solution are derived.
Cuplength estimates on lagrangian intersections
Authors: Floer Andreas
Published: April 2007

We prove the following estimate on Lagrangian intersections: If L is a Lagrangian submanifold of P with π2(P, L) = 0 and L' is obtained from L by an exact diffeomorphism of P, then the number of elements of L ∩ L' is greater than or equal to the cuplength of P.
Nonlinear theory of defects in nematic liquid crystals; Phase transition and flow phenomena
Authors: Lin Fang‐Hua
Published: April 2007

This is a summary of some recent mathematical advances in the theory of defects in nematic liquid crystals. It also includes some new results concerning disclinations (line defects) which have not been published elsewhere.
Stability theorem and truncation error analysis for the Glimm scheme and for a front tracking method for flows with strong discontinuities
Authors: Chern I‐Liang
Published: April 2007

Typical nonlinear wave interaction problems involve strong waves moving through a background of weak disturbance. Previous existence theorems and error analysis for computations are usually restricted to more idealized situations such as small data or single equations. We consider here the problem of a single strong discontinuity interacting with a weak background for general hyperbolic systems of conservation laws. We obtain the stability, consistency theorems and upper bounds of the truncation errors for the Glimm scheme and for a front tracking method. The major error in the Glimm scheme is the error generated by the strong discontinuity. This error is reduced when a front tracking method is applied to follow the location of the strong discontinuity. This demonstrates an advantage of front tracking methods in one‐space dimension.
Extension of Hilbert's tenth problem to some algebraic number fields
Authors: Shlapentokh Alexandra
Published: April 2007

We extend the solution of Hilbert's tenth problem to algebraic number fields having one pair of complex conjugated embeddings. The proof is based on the extended method of J. Denef used for totally real algebraic number fields.