Copulatory behavior can inhibit pregnancy in female rats.

If female rats received genital stimulation soon enough after their male partners had ejaculated, sperm transport and subsequent pregnancy were inhibited. Manual stimulation by the experimenter or five intromissions by a male rat were sufficient stimuli to reduce the number of sperm found in the uterus and to reduce the number of uterine implantation sites.

Neural lateralization of species-specific vocalizations by Japanese macaques (Macaca fuscata).

Five Japanese macaques and five other Old World monkeys were trained to discriminate among field-recorded Japanese macaque vocalizations. One task required discrimination of a communicatively relevant acoustic feature ("peak"), and a second required discrimination of an orthogonal feature of the same vocalizations ("pitch"). The Japanese animals more proficiently discriminated the peak feature when stimuli were presented to the right ear (primarily left cerebral hemisphere), as opposed to the left ear (primarily right hemisphere). In discriminating the pitch feature, the Japanese animals either showed (i) a left-ear processing advantage or (ii) no ear advantage. The comparison animals, with one exception, showed no ear advantage in processing either feature of the vocalizations. The results suggest that Japanese macaques engage left-hemisphere processors for the analysis of communicatively significant sounds that are analogous to the lateralized mechanisms used by humans listening to speech.

Species-specific perceptual processing of vocal sounds by monkeys.

Monkeys of four species were trained to discriminate between sets of natural tonal calls of Japanese macaques (Macaca fuscata) by the position of a frequency-inflection peak or by initial pitch. The Japanese macaques consistently performed best on peak position and the other species on pitch. The results imply special strategies for perceptional processing of vocal sounds and suggest parallels with human speech perception.

Patterns of mortality among commercial pressmen.

A proportionate analysis of cause of death in 1,401 commercial pressmen was initiated following a report of a cancer cluster in this group. The study found a significant elevated risk of all cancers [proportionate mortality ratio (PMR) = 127] and cancers of the lymphatic and hematopoietic system (PMR = 122), with non-Hodgkin's lymphomas responsible for much of the excess. Three deaths in the cohort were attributed to myelofibrosis, a rare disease associated with benzene exposure. A significantly elevated PMR was also detected for colorectal cancer (PMR = 171) and, among those employed 20 years or more, for cancers of the liver (PMR = 216) and pancreas (PMR = 162). No excess risk of bladder or lung cancer or leukemia was seen. Proportionate mortality analyses rarely show excess risk of both cancer and heart disease in a working population. Surprisingly, a significantly elevated risk of arteriosclerotic heart disease (PMR = 113) was found in this group. These findings indicate that solvent exposure may be associated with excess mortality risk in commercial pressmen.

Mortality among urban bus drivers.

Driving a bus in urban areas is considered to be a highly stressful occupation, one which also involves exposure to air pollutants generated by motor vehicles. In order to investigate the potential health hazards associated with this occupation, the causes of death of 376 New York City bus drivers were studied. Analyses of proportionate mortality found a significant excess due to ischaemic heart disease in drivers in both races combined (proportionate mortality ratio PMR = 1.23), and among the 58 non-white drivers (PMR = 1.72). A significantly elevated risk of death from mental, psychoneurotic and personality disorders (ICDA Ninth Revision 290-319, which includes alcoholism and narcotics abuse) was also found in the combined group (PMR = 2.66), and among the white drivers (PMR = 3.05). For all drivers, PMRs for all malignant neoplasms (PMR = 1.26) and for cancer of the oesophagus (PMR = 2.54) were significantly elevated. No cancer sites were found to be significantly elevated in the proportionate mortality analyses by race. These findings are consistent with the growing body of literature linking job strain with cardiovascular disease among bus drivers.

Does low-level lead exposure increase risk of death? A mortality study of newspaper printers.

This exploratory study examined the mortality experience of a cohort of newspaper printers in order to investigate the effects of low-level exposure to lead. In this industry, historic lead exposure levels have been below the current US permissible exposure level (PEL) of 50 micrograms/m3. The study population was 1261 typesetters, employed in 1961 and followed until the end of 1984; this was a cohort of convenience, assembled as a comparison for a different study. Standardized mortality ratios (SMRs) were calculated using New York City comparison rates. The all-cause SMR was 0.74, and was significantly different from 1.00. Other statistically significant deficits were deaths from arteriosclerotic heart disease (SMR = 0.63) and non-malignant diseases of the respiratory system (SMR = 0.57) and digestive system (SMR = 0.65). These can be attributed to the comparison bias known as the healthy worker effect. The SMR for cerebrovascular disease (CVD) was 1.35, on the edge of statistical significance (95% confidence interval (CI): 0.98-1.82). When the cohort was stratified by years of union membership, a surrogate for length of exposure, only one cause of death was significantly elevated. For those printers employed for 30 years or more, the CVD SMR was 1.68 (95% CI: 1.18-2.31; p = 0.002). No significant excesses were seen for any other cause of death in any exposure stratum. Several studies of workers with much higher levels of lead exposure have reported elevated CVD risk. These findings suggest the possibility that lead exposure at levels below the current US PEL may also be associated with CVD mortality.

Neural lateralization of vocalizations by Japanese macaques: communicative significance is more important than acoustic structure.

The study was designed to determine whether the neural lateralization of vocal perception in Japanese macaques depends on the acoustic properties of the calls used or their communicative significance. Four monkeys--two Japanese macaques and two comparison macaques--were trained to discriminate among monaurally presented exemplars of two classes of vocalizations from the Japanese macaque's repertoire. Once the subjects mastered the discrimination, they performed at equivalent accuracy levels for 150 sessions. However, during this time the Japanese monkeys showed a right ear performance advantage, whereas the comparison monkeys showed no ear advantage. In order to assess whether the comparison and Japanese monkeys were attending to the same acoustic cue when performing the discrimination, a generalization test was conducted with 27 novel vocalizations. The individual monkeys' generalization gradients were highly similar and revealed that all subjects were in fact listening to the same feature of the calls. These findings, coupled with the fact that the calls were of biological significance to the Japanese monkeys alone, suggest that the laterality effect is related, in some fashion, to the communicative valence of the signals rather than their purely physical characteristics.

Exposure of sheet-metal workers to asbestos during the construction and renovation of commercial buildings in New York City. A case study in social medicine.

New York City sheet-metal workers have a history of significant exposure to asbestos. Prior to 1972 when the use of sprayed asbestos insulation was banned in New York City, sheet-metal workers involved in building construction were exposed as they worked adjacent to spraying operations. Subsequent to that date, exposure continued as they renovated these same buildings. In 1982 the Occupational Health Program of Montefiore Medical Center and the Albert Einstein College of Medicine initiated a multidimensional asbestos evaluation and intervention program for the sheet-metal industry and union in New York. The long-term goal of the program was to eliminate asbestos exposure through the safe, systematic removal of asbestos in New York City buildings, most likely a legislated solution. In the short term, we attempted to assess and reduce asbestos exposure in the sheet-metal trade by a series of steps consisting of: mortality and morbidity studies; a medical audit of clinical screening services provided to sheet-metal workers; a comprehensive health education program; development of safe work practices; evaluation of personal protective equipment; and investigation into and support of legislative and regulatory solutions to the problem of asbestos contamination of commercial buildings. This intervention can be seen as a case study in the practice of social medicine.

Impact of a joint labor-management ergonomics program on upper extremity musculoskeletal symptoms among garment workers.

This study evaluated the effect of an ergonomics intervention program on the prevalence and intensity of symptoms of upper extremity work-related musculoskeletal disorders among 36 garment workers performing an operation called spooling. Adjustable chairs were introduced and workers were trained in their use. Symptom surveys were administered prior to and 6 months after introduction of adjustable chairs. Quantitative pre- and post-intervention measurement of joint position was performed utilizing videotapes among a subgroup of nineteen. Eighty nine percent of the cohort reported pain in either the neck or at least one upper extremity anatomic site prior to the adjustable chair intervention. Among subjects reporting pain at baseline, there were significantly decreased pain levels in 10 of 11 anatomic sites after the intervention. Among all subjects, the proportion reporting pain decreased for each anatomic site following the intervention, with statistically significant decreases in 3 sites. However, there were only modest declines in awkward posture among the videotaped subgroup. This study suggests that introduction of an ergonomics program focused on education and introduction of an adjustable chair may diminish musculoskeletal symptomatology in apparel manufacturing workers.

Asbestos disease in sheet metal workers: proportional mortality update.

This paper, updating the findings of an earlier study, provides additional evidence that sheet metal workers in the construction trades are at increased risk for asbestos-related disease. A proportional analysis of cause of death among 331 New York sheet metal workers found a significantly elevated PMR for lung cancer (PMR = 186). In addition, there were six deaths attributable to mesothelioma (three classified as lung cancer deaths) and three death certificates mentioned asbestosis or pulmonary fibrosis, although none of these three deaths were attributed to these diseases.

Monkey vocalizations and human speech: parallels in perception?

Primate vocal repertoires may be classified along a continuum of discrete vs. graded signals, with the placement of a particular repertoire a result of the interplay between the species' social organization and adaptive specializations of individual signals engendered by the physical environment and their use. Discussion of the different types of graded signals reveals that they may possess either transitional, ontogenetic, or internal variability. Upon examination, the speech of humans is found to contain primarily internally graded signals, and it is suggested that the major phenomena of human speech perception are related to this internally graded quality. Based on this analysis of human speech, it is proposed that other species possessing internal gradings (e.g., Japanese macaques) are also likely to demonstrate similar perceptual phenomena for their own graded vocalizations.

Asbestos disease in sheet metal workers: the results of a proportional mortality analysis.

The results of a proportional mortality analysis of a cohort of sheet metal workers who have only intermittent exposure to asbestos demonstrates a significant excess of cancer at the three sites most frequently associated with asbestos: lung, colon and rectum, and the mesothelium. No excess nonmalignant respiratory disease was detected. These data strongly suggest that significant asbestos-related disease is present in populations with secondary exposure to asbestos and emphasize the importance of considering possible asbestos-related disease when treating patients with a history of employment in the construction industry.

Auditory sensitivity, equal loudness, temporal resolving power, and vocalizations in the house finch (Carpodacus mexicanus).

Absolute thresholds for pure tones were measured in four house finches by use of avoidance conditioning and a modified method of limits. Response reaction time to each tone presentation served as a data base for generating a family of "equal loudness" contours. Temporal resolving power was measured in two additional birds and compared with similar measures in man. The results are discussed in relation to previous studies of vocalizations in the house finch, and the average power spectra of selected individual vocalizations are presented.

Human immunodeficiency virus infection care is unavailable to inmates on release from jail.

BACKGROUND: The human immunodeficiency virus (HIV) seroprevalence in urban jails is higher than that in the general community. METHODS: We interviewed a cohort of HIV-infected inmates in a jail in New York, NY, during incarceration and after release to assess the accessibility of medical and social services. RESULTS Of the 170 inmates who were interviewed and released into the community, 40 (24%) came to a follow-up interview. Of the 40, 25 (62%) had not received an appointment with an infectious disease clinic by the time of the new interview. Only eight (27%) of the 32 who received zidovudine in jail obtained zidovudine; and only one of the 13 who received isoniazid prophylaxis in jail obtained isoniazid prophylaxis. Twenty (65%) had applied for but not yet received Medicaid. CONCLUSION: Inmates infected with HIV may encounter difficulties obtaining medical care and social services on release into the community, which can potentially lead to active infectious tuberculosis. Family physicians may encounter HIV-positive patients who are newly released from jail and who need follow-up medical care, and they must help address the needs of HIV-positive, formerly incarcerated people.

The National Sheet Metal Worker Asbestos Disease Screening Program: radiologic findings. National Sheet Metal Examination Group.

This report presents data gathered from a series of asbestos disease screening examinations of 9,605 United States sheet metal workers who were first employed in the trade at least 20 years before the examination. The overall prevalence of asbestos-related radiographic changes was 31.1%: 18.8% had pleural abnormalities alone, 6.6% had parenchymal abnormalities (International Labour Office (ILO) score of 1/0 or higher) alone, and 5.7% had both. Among those with 40 years or more since entering the trade, 41.5% had radiographic signs of asbestos-related disease, 24.2% pleural alone, 7.7% parenchymal alone, and 9.6% both pleural and parenchymal abnormalities. After controlling for several surrogates for asbestos exposure level, cigarette smoking was found to increase risk of parenchymal, and more modestly, pleural abnormalities. Each pack-year was associated with a 1% increased prevalence odds ratios for parenchymal abnormalities (ILO category 1 compared to category 0), and 0.4% increased prevalence odds ratios for pleural abnormalities. A history of shipyard employment also produced significantly increased prevalence odds ratios for each radiographic category. More that 90% of chest radiographs were classified by A or B readers; after adjustment for other risk factors, A readers were more likely to report parenchymal abnormalities of category 1, but not more likely to report category 2 or pleural abnormalities, than B readers.

Workshops are not enough: making Right-to-Know training lead to workplace change.

The underlying intent of Right-to-Know laws and regulations is to improve workplace conditions through worker empowerment. These regulations require employers to educate their employees about the nature and hazards of toxic substances found in the workplace, and methods to reduce exposure. This paper describes a Right-to-Know training program for over 4,000 local government employees which involved workers, their union, and management in the planning, implementation, and evaluation of the program. A combination of quantitative and qualitative evaluation determined the program was successful at individual, group, and structural levels. The evaluation results suggest that Right-to-Know training programs can make an important contribution to improving workplace health and safety when they are a well-integrated component of a comprehensive safety and health program: they use participatory training methods, they are tailored to address specific conditions faced by the participants, and there is active labor-management collaboration.