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Daily subcutaneous injection of L-dopa for 4 weeks into 2-year-old low egg production hens resulted in a lightening of feather color to snow white and increased oviduct and ovary weights and the development of well developed follicles. However, the rate of egg production during administration did not increase.
Since the finding in the 1930s, a large number of polycyclic aromatic hydrocarbons (PAHs) of different structures have been tested for potential tumorigenicity. Structure-activity relationships of halo-PAHs have been investigated to determine the regions of a PAH that may be involved in cancer initiation. From these studies, a number of halo-PAHs were found to be tumorigenic in experimental animals. It was not until the 1980s that halo- PAHs were found to be present in the environment, including municipal incinerator fly ash, urban air, coal combustion, soil, snow, automobile exhausts, and tap water. Due to their widespread presence in the environment and their genotoxic activities, including carcinogenicity, many of these compounds may pose a health risk to humans. Although the biological activities, including metabolism, mutagenicity, and carcinogenicity, of halo- PAHs have been studied their phototoxicity and photo-induced biological activity have not been well examined. In this study, we study the photoirradiation of a series of structure-related halo-PAHs by UVA light in the presence of a lipid, methyl linoleate, and determine as to whether or not these compounds can induce lipid peroxidation. The halo-PAHs chosen for study include 2-bromonaphthalene, 1-chloroanthracene, 9,10- dibromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 7-chlorobenz[a]anthracene, 7- bromobenz[a]anthracene, 7-bromo-5-methylbenz[a]anthracene, 6-chlorobenzo[a]pyrene, and 6- bromobenzo[a]pyrene. The results indicate that upon photoirradiation by UVA all these compounds induced lipid peroxidation at different levels. These results suggest that halo-PAHs may be harmful to human health.
OBJECTIVES: This study was conducted to learn from snow crab plants workers and others involved in the industry their knowledge and beliefs of health issues and potential solutions. STUDY DESIGN: This is a survey in four communities with different crab plant designs in Newfoundland and Labrador, Canada. METHODS: At the start of a meeting to discuss crab asthma participants were requested to complete the questionnaire. RESULTS: 65% of 196 participants believed there were health problems associated with crab plants. 85% have heard of crab asthma. Almost 80% identified correctly the major symptoms of crab asthma as difficulty breathing, chest tightness and cough. Only 74% of workers did not know that workers with crab asthma were eligible for workers' compensation. 55% of those surveyed had heard of crab asthma from crab plant workers and only 26% from their doctor or nurse. If they had breathing problems, 73% would see their local doctor, and 51% a specialist and 51% their nurse. CONCLUSION: The majority of participants believed that there were health problems associated with crab plants. The majority of crab plant workers could identify symptoms of crab asthma correctly. Many do not know that those with crab asthma can obtain workers' compensation. Most of them learn of crab asthma from other workers but would seek treatment from their doctor.
OBJECTIVES: To test the hypothesis that the unexpectedly low prevalence of winter depression in Iceland is explained by Icelanders enjoying more daylight, during the winter months, than allocated to them by latitude. METHODS: A conventional photometer was applied to measure illuminance on a horizontal surface at 64 degrees 8.8' N and 21 degrees 55.8' W every minute throughout the year. The illuminance thus measured was compared with computed illuminance, based on theoretical upper bounds. RESULTS: Daylight availability proved to be, on average, 60% of the theoretical upper bounds derived using clear sky conditions. Snow cover did not, on average, cause a significant increase in daylight availability. Great variability was observed in illuminance from day to day, as well as within days. CONCLUSIONS: Average daylight availability does not explain the lower than expected prevalence of winter depression in Iceland. The great variability in illuminance might, however, affect the expression of winter depression, as could daylight quality and genetic factors.
OBJECTIVES: The purpose was to describe the significance of the physical environment in supporting the well-being of the elderly aged over 65 years. The aim was to produce knowledge that will complement the knowledge-base of gerontologic nursing. STUDY DESIGN: The study was qualitative. Thirty-nine home-dwelling elderly persons aged over 65 were interviewed. METHODS: The interviews (n = 39) were conducted with the thematic method. The data were analysed with methods of inductive content analysis. RESULTS: The main threats of the northern physical environment to the well-being of the elderly are seasonal variation, temperature, snow, light variation and distances. The supportive characteristics of the northern environment are the natural environment, space, familiarity with the physical space, cleanliness and safety. CONCLUSION: The characteristics of the northern physical environment seem to be significant for both urban and rural elderly people living in the northern part of Finland. The different aspects of the natural environment provide opportunities to relax, meet other people and do physical exercise, all of which are important factors of health promotion.
Plaque reduction-serum dilution neutralization was used to evaluate the status of bunyavirus activity in deer in mountainous areas of California. Antibodies against 9 bunyaviruses were measured in 337 mule deer (Odocoileus hemionus hemionus, O. hemionus californicus, and O. hemionus inyoensis) and black-tailed deer (O. hemionus columbianus). More deer from high mountainous areas had neutralizing antibodies against Jamestown Canyon virus than did deer from low mountainous areas (23% vs. 9%; P less than 0.01). This finding is consistent with transmission by snow pool Aedes mosquitoes. Results for Jerry Slough virus were nearly identical to those for Jamestown Canyon virus, which is further evidence that these are strains of the same virus. Neutralizing antibodies against Northway virus were present in 26% of deer from high mountainous areas and 23% of deer from low mountainous areas, suggesting the involvement of a widespread vector, such as Culiseta inornata. Northway virus is not known to occur outside of Alaska and northwestern Canada. Low prevalences of antibodies were detected in deer to California encephalitis, La Crosse, and snowshoe hare viruses of the California serogroup; and Cache Valley, Lokern, and Main Drain viruses of the Bunyamwera serogroup.
The microbiological contamination of reindeer carcasses was studied in 10 Finnish reindeer slaughterhouses. Six of the slaughterhouses were field slaughterhouses and four were plant slaughterhouses. In each slaughterhouse 11 to 30 carcasses were sampled, with abdomen, brisket, and foreleg as sampling sites. Sampling was performed immediately after slaughter, using a nondestructive swabbing method. The overall mean bacterial count of carcasses was 3.12+/-0.61 log CFU/cm2. The mean bacterial value of the carcasses and the bacterial counts of abdomen and brisket were significantly lower in field slaughterhouses than in plant slaughterhouses, suggesting that the controlled conditions of plant slaughterhouses do not necessarily improve the microbiological quality of reindeer carcasses. However, the highest bacterial contamination was found in a field slaughterhouse where the slaughter was performed after rain when the ground was without snow. Carcass contamination seemed to be increased by the use of an evisceration apron, the unnecessary washing of forelegs, and the unnecessary handling of carcasses with hands and arms.
Enteric viruses, including hepatitis A, Norwalk, and Snow Mountain viruses, Hawaii agent, and rotaviruses have been associated with outbreaks of foodborne illness. Classical culturing procedures are available for poliovirus; however, hepatitis A, Norwalk, and many of the other viruses and agents cannot be propagated in cell culture, therefore, molecular biological tools have emerged as a possible means to detect enteric viruses in foods and environmental samples. There are limitations however in the application of polymerase chain reaction and reverse transcription polymerase chain reaction that restrict their usefulness for measuring the virological safety of foods. The most serious limitation is that molecular techniques fail to discriminate between viable and inactivated viruses even though inactivated viruses pose no threat to the consumer and may be present at levels substantially higher than the virulent forms. Other disadvantages include a lack of assay sensitivity and specificity, high assay costs, and a level of technical expertise not available in most food-testing laboratories. Overall, scientific advances in the development of molecular biological tools have outpaced the demonstration of their validity in assessing the virological safety of foods.
OBJECTIVE: Effects of a 6-day snow skiing trip on 14 adolescents with limb deficiencies were explored. The purpose was to determine whether components of mastery and self-esteem could be identified. METHOD: Participant observation data collection methods included videotape, interviews, daily progress notes by ski instructors, and a 1-month posttrip questionnaire. Data were analyzed for evidence of efficiency, effectiveness, and satisfaction to self and others (properties of relative mastery described in occupational adaptation.) Skier reports of positive effects were analyzed for indications of an impact on self-esteem. Three occupational therapists who have extensive experience working with adolescents also reviewed videotapes and written information. RESULTS: The therapists acknowledged the presence of skill mastery as an important component of skiers' positive self-evaluation. They also commented that evidence of preexisting self-esteem and social aspects of the trip were as likely to produce positive effects as mastery of skiing. CONCLUSION: Research method considerations (use of participant observation for hypothesis testing) preclude definitive interpretation of a link between skill mastery and self-esteem. Short-term positive effects of the skiing experience reported by questionnaire were present 1 month after the trip. Long-term effects should be studied.
In Japan daily motorcycle mail deliverers have been exposed to vibration from the handlebars of their motorcycles. Handlebar vibration was measured during the operation of a motorcycle in order to evaluate the hazardous effects of vibration and to identify preventive measures against the vibration hazards. Tests were made on asphalted, unpaved, and packed-snow road surfaces. The tested motorcycles were selected from the many motorcycles in daily use. The test motorcycle was a 1-cylindered, 89-cm3, 4-cycle machine. The direction showing the maximum value of vibration acceleration was not always in the directions of X, Y, and Z proposed by the International Organization for Standardization (ISO). The maximum vibration acceleration level exceeded the exposure guideline of ISO, while its frequency corresponded to that of the engine speed during operation. Vibration of greater than 20 Hz was transmitted through the front forks from the road surface and tires.
Avian cholera was diagnosed in lesser snow geese (Anser c. caerulescens), Ross' geese (Anser rossii) and individuals of several other waterfowl species in a small area of south-western Saskatchewan over a 1 month period during the 1977 spring migration. Approximately 250 dead birds were found. This is apparently the first time avian cholera has been reported in migrating waterfowl in Canada. The site of the mortality was midway between the wintering and nesting areas of the two principal species, and the significance of the occurrence of the disease this far north is discussed.
Waterfowl mortality caused by aflatoxicosis occurred in two separate areas in Texas during the 1977-78 wintering season. The first outbreak occurred in snow geese (Anser caerulescens) on the Gulf Coast prairies, followed by an outbreak in mallards (Anas platyrhynchos) in the north-central portion of the state. Aflatoxin B1 levels in geese were 500 ng/g (dry weight). Aflatoxin B1 levels in the second mortality were 10-250 ng/g (dry weight). The exact source of the toxin was not demonstrated in the first outbreak, but in the second outbreak was traced to waste peanuts, which constituted a major portion of the diet of wintering waterfowl in north-central Texas. Aflatoxin B1 levels in the field peanuts collected in the general areas were 110 ng/g.
Outbreaks of a disease characterized by severe necrotic enteritis occurred among Canada geese (Branta canadensis), lesser snow geese (Anser caerulescens), Ross' geese (A. rossi), and white-fronted geese (A. albifrons) on lakes in Saskatchewan and Manitoba during the autumn of 1983, 1984 and 1985. Ducks using the lakes were apparently not affected. Lesions in the geese closely resembled those described in enteritides in other species associated with the proliferation of Clostridium perfringens in the small intestine. Clostridium perfringens was present in large numbers in the affected areas of the intestine of the geese; other pathogens were not identified. It is hypothesized that an abrupt change in diet as geese begin to feed on grain disrupts the intestinal microflora, allowing C. perfringens to proliferate in the upper small intestine. Toxins produced by the bacteria then cause mucosal necrosis. Protease-inhibitory substances in some grains might also have a role in the disease.
Characteristics of Pasteurella multocida isolated from tissues of dead waterfowl and associated avian species found at 23 sites located in northern and central California, from January 1986 through January 1988 are reported. Two hundred ninety five isolates of P. multocida were obtained from 23 avian species. Most of the isolates belonged to the subspecies P. multocida multocida (63%), followed by P. multocida gallicida (37%), and by P. multocida septica (less than 1%). There appeared to be a higher prevalence of P. multocida multocida in Ross' geese (Chen rossi) and Snow geese (Chen coeruleus). All of the isolates belonged to somatic serotype 1, possessed the A capsule type and were susceptible to the 8 antimicrobial agents tested. None contained plasmid DNA.
Ten Canada geese (Branta canadensis), 24 snow geese (Chen caerulescens) and 22 white-fronted geese (Anser albifrons) from coastal Texas (USA) were examined for helminths. Three cestode, seven nematode, and three trematode species were collected. Gizzard nematodes (Amidostomum anseris, A. spatulatum and Epomidiostomum crami) infected 53 of 54 birds. Gross lesions were not attributed to helminth infections and the host population does not appear to be impaired by them.
Thirty-seven carcasses of Eurasian lynx (Lynx lynx) collected and examined in Estonia during 1999-2001 had helminths. Parasites identified and their prevalence included Diphyllobothrium latum (5%), Taenia pisiformis (100%), Taenia laticollis (41%), Taenia hydatigena (3%), Taenia taeniaeformis (3%), Toxocara cati (68%), and Trichinella spp. (22%). The only significant relationships (P < or = 0.05) between occurrence of helminths and host age and sex were a greater number of T. pisiformis and T. laticollis in older than in youger male lynx, and older males had a greater number of species of helminth than did younger lynx. Sixty-one fecal samples collected during snow tracking of nine lynx were examined; eggs of T. cati were identified in 38 samples, and Capillaria spp were found in eight samples. This is the first systematic investigation of parasites of lynx in Estonia.
Two incidents are reported in which groups of migrating wild geese were found dead in agricultural fields in southern Manitoba during spring. In each case, the birds died overnight and poisoning was suspected; however, the birds had lesions of severe traumatic injury. The first incident, in 1985, involved about 150 lesser snow geese (Anser caerulescens caerulescens); the second, in 2003, involved 62 Canada geese (Branta canadensis). Both incidents occurred on dark, moonless nights. One possible explanation is that the birds became disoriented in a manner analogous to spatial disorientation described in aircraft pilots and flew as a flock directly into the earth. In the first incident, geese might have been frightened by sonic booms from aircraft; in the second, there was a thunderstorm with strong gusty winds in the area.
We conducted a 3-yr study (2001-03) on greater white-fronted geese (Anser albifrons frontalis) breeding in Alaska, USA, to determine the exposure of this population to Pasteurella multocida and the potential role of these birds as disease carriers. We tested sera from nearly 600 adult geese for antibodies to P. multocida serotype 1. We found a low prevalence (<5%) of positive antibodies in adult geese, and based on the short duration of detectable antibodies, these findings indicate recent infection with P. multocida. Prevalence was similar to serologic results from both breeding and wintering lesser snow geese. We also collected oral (n=1,035), nasal (n=102), and cloacal (n=90) swab samples to determine the presence of avian cholera carriers in this population. We were unable to isolate P. multocida serotype 1 from any of the birds sampled. Based on comparison with other waterfowl species, we concluded that these geese may be exposed to avian cholera during the winter or spring migration but are unlikely to play a significant role as carriers of the bacterium causing avian cholera.