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PubMedDate not supplied

Decomposition of aqueous diphenyloxide by ozonolysis and by combined gamma-ray-ozone processing.

Diphenyloxide (DPO) is one of many, rather toxic pollutants produced by combustion of fossil fuels, which are emitted to the atmosphere with flue gases and brought to ground water by rain and snow. Its decomposition is investigated by ozonolysis at room temperature and the major products like phenol, resorcinol, hydroquinone, dihydroxy-benzoic acid as well as the total yield of aldehydes and carboxylic acids were determined as a function of applied ozone concentration. In addition, the DPO-degradation was studied by a combined action of gamma-ray under continuous bubbling of a known ozone concentration. In this case the formation of the same products is observed, but their yields differ from the above ones. Based on the synergistic action of ozone and gamma-ray the DPO-radiolysis is rather efficient, leading to an initial-G-value of 11.3. Some probable reaction mechanisms are presented for explanation of the degradation process.

Environmental Pollutants↗
PubMed1999

Role of oestradiol in the regulation of the seasonal antler cycle in female reindeer, Rangifer tarandus.

Reindeer (or caribou), Rangifer tarandus, is the only extant species of deer in which females as well as males normally develop antlers that are cast and regrown each year. This study investigated the role of ovarian oestradiol in the regulation of the seasonal antler cycle in female reindeer. Ovariectomized Norwegian reindeer living outdoors in northern Norway (69 degrees N) were treated with continuous-release subcutaneous Silastic implants containing oestradiol, which maintained the blood concentrations of oestradiol within the physiological range for the mating season from June to October-November. The treatment with oestradiol induced the synchronized maturation of the antlers and rapid cleaning of the velvet-like skin in August-September in the ovariectomized reindeer, a pattern very similar to that observed in ovary-intact controls living under the same conditions. The removal of the steroid implant in October-November caused the premature casting of the antlers in early winter in two of five animals, while the remainder cast at the normal time in spring; this response was seen whether the animals had received one or two oestradiol implants in autumn. The antlers developed by the ovariectomized, oestradiol-treated females were significantly heavier and carried more branches than the ovariectomized animals without oestradiol replacement, and were marginally heavier than the antlers of intact controls. These results support the view that oestradiol is the biologically active steroid secreted by the ovary in intact female reindeers that induces the normal development of the antlers. Oestradiol stimulates the growth and mineralization of the antler bone, the cleaning of the velvet, and suppresses the casting of the hard antlers. This endocrine control ensures that the hard antlers, which function as weapons, are retained throughout the autumn and winter when the females are normally pregnant and when competition between females over food in the snow is most intense; hence there is a reproductive advantage to explain the evolution of antlers in females.

Animals↗
PubMed2001

Albedo-enhanced maximum UV irradiance--measured on surfaces oriented normal to the sun.

UV radiation measured on normal-to-the-sun-oriented surfaces can show significantly higher global UV irradiance values compared to measurements on horizontal receivers. The direct component is amplified by the inverse cosine of the zenith angle, but over surfaces with high local albedo this accounts for only about half of the signal rise of global irradiance. The signal rise of the diffuse component, however, is strongly related to local albedo and solar elevation, which is demonstrated by 2 years of measurements of direct, diffuse, global, reflected and global normal-to-the-sun erythemal effective UV irradiance (UVery). Global UVery signal rises, on normal-to-the-sun-oriented versus horizontal receivers, of up to 65% were measured on fresh snow and solar elevation angles below 30 degrees. An empirical expression has been deduced from the measurements relating the ratio of normal-to-the-sun versus horizontal measurements of global UVery to surface albedo and solar elevation. This allows one to calculate the maximum global UVery irradiance levels which are to be expected on normal-to-the-sun-oriented surfaces with respect to horizontal measurements or model calculations.

Journal Article↗
PubMedDate not supplied

Biological monitoring of solar UV radiation at 17 sites in Asia, Europe and South America from 1999 to 2004.

A small and robust dosimeter for determining the biologically effective dose of ambient UV radiation has been developed using UV-sensitive mutant spores of Bacillus subtilis strain TKJ6312. A membrane filter with four spots of the spores was snapped to a slide mount. The slide was wrapped and covered with two or more layers of polyethylene sheet to protect the sample from rain and snow and to reduce monthly-cumulative doses within the measurable range. From 1999, monthly data were collected at 17 sites for more than 1 year, and data for 4 to 6 consecutive years were obtained from 12 sites. Yearly total values of the spore inactivation dose (SID) ranged from 3200 at subarctic Oulu to 96 000 at tropical Denpasar, and the mean yearly values of SID exhibited an exponential dependence on latitude in both hemispheres with a doubling for about every 14 degrees of change. During the observation period, increasing trends of UV doses have been observed at all sites with more than 5 years of data available. Year-to-year variations at high and middle latitude sites are considered due mostly to climatic variation. At three tropical sites, negative correlations between the yearly doses and the column ozone amounts were observed. The results verified the applicability of spore dosimetry for global and long-time monitoring of solar UV radiation, in particular at tropical sites where no monitoring is taking place.

Asia↗
PubMed2001

20th century climate warming and tree-limit rise in the southern Scandes of Sweden.

Climate warming by ca. 0.8 degree C between the late-19th and late-20th century, although with some fluctuations, has forced multispecies elevational tree-limit advance by > 100 m for the principal tree species in the Swedish part of the Scandinavian mountain range. Predominantly, these processes imply growth in height of old-established individuals and less frequently upslope migration of new individuals. After a slight retardation during some cooler decades after 1940, a new active phase of tree-limit advance has occurred with a series of exceptionally mild winters and some warm summers during the 1990s. The magnitude of total 20th century tree-limit rise varies with topoclimate and is mainly confined to wind-sheltered and snow-rich segments of the landscape. Thickening of birch tree stands in the "advance belt" has profoundly altered the general character of the subalpine/low alpine landscape and provides a positive feedback loop for further progressive change and resilience to short-term cooling episodes. All upslope tree-limit shifts and associated landscape transformations during the 20th century have occurred without appreciable time lags, which constitutes knowledge fundamental to the generation of realistic models concerning vegetation responses to potential future warming. The new and elevated pine tree-limit may be the highest during the past 4000 14C years. Thus, it is tentatively inferred that the 20th century climate is unusually warm in a late-Holocene perspective.

Climate↗
PubMed2003

Disinfection of septic tank and cesspool wastewater with peracetic acid.

Wastewaters of private household septic tanks and cesspools have been treated with peracetic acid (1-2 g L(-1)). Adding 1 g L(-1) peracetic acid to wastewaters was easy and has been found to be effective in destroying enteric indicator microorganisms. The careful mixing of peracetic acid and wastewater was found to be important. Winter periods with frozen soil, ice and snow did not constitute extra problems. The bad smell of these wastewaters almost totally disappeared during the treatment. When wastewaters treated with peracetic acid were emptied into animal slurry tanks, hygienization still continued in the mixture of animal slurry and the wastewaters. These wastewaters could thus be released into agricultural soil without risk of microbiological pollution to groundwaters.

Disinfectants↗
PubMed2006

Perceived and measured levels of environmental pollution: interdisciplinary research in the subarctic lowlands of northeast European Russia.

Using interdisciplinary field research in the Usa Basin, northeast European Russia, we compared local inhabitants' perception of environmental problems with chemical and remote-sensing signatures of environmental pollution and their local impacts. Extensive coal mining since the 1930s around Inta and Vorkuta has left a legacy of pollution, detected by measuring snowpack, topsoil, and lichen chemistry, together with remote-sensing techniques and analysis of lake water and sediments. Vorkuta and its environs suffered the worst impacts, with significant metal loading and alkalization in lakes and topsoils, elevated metals and cations in terricolous (reindeer) lichens, and changes in vegetation communities. Although the coal industry has declined recently, the area boasts a booming oil and gas industry, based around Usinsk. Local perceptions and concerns of environmental pollution and protection were higher in Usinsk, as a result of increased awareness after a major oil spill in 1994, compared with Vorkuta's inhabitants, who perceived air pollution as the primary environmental threat. Our studies indicate that the principal sources of atmospheric emissions and local deposition within 25 to 40 km of Vorkuta were coal combustion from power and heating plants, coal mines, and a cement factory. Local people evaluated air pollution from direct observations and personal experiences, such as discoloration of snow and respiratory problems, whereas scientific knowledge played a minor role in shaping these perceptions.

Air Pollutants↗
PubMed1997

Medical problems of porters and trekkers in the Nepal Himalaya.

The purpose of this study was to assess the incidence of medical illness among members of trekking groups in the Nepal Himalaya. The design was a cohort study using interview and clinical examination by a single physician. The setting was the Manaslu area in the central Nepal Himalaya along a 22-day trekking route with elevations ranging from 487 m to 5100 m. Subjects were 155 members of commercial trekking groups: 102 Nepali porters, 31 Nepali trek staff, and 22 Western trekkers. We found that medical problems occurred in 45% of party members. The porter cohort contained the highest diversity and severity of illness. The relatively larger porter cohort experienced 77% of the medical problems recorded compared with 17% among Western trekkers and 6% among trek staff. The incidence of medical problems was not significantly different in the porter staff (52%) and Western trekkers (55%) and was significantly lower for the trek staff (13%). High-altitude pharyngitis/bronchitis was the most common illness in the party (12%) followed by acute mountain sickness (8%) and gastroenteritis (6%). Other conditions included anxiety (3%), cellulitis (3%), scabies (3%), snow blindness (3%), acute alcohol intoxication (2%), conjunctivitis (2%), fever (2%), lacerations (2%), and hemorrhoids (1%). Illness with infectious etiologies comprised 33% of the medical problems. The incidence of altitude illness was not significantly less in the Nepali porter staff than in the Western trekkers. Evacuation was required in 5% of party members, all from the porter group. This study should alert expedition medical providers and trip leaders of the need to be observant for and prepared to treat the frequent and diverse medical problems among the porter staff in their party, in addition to the Western members. Medical problems are common in remote mountainous areas, indicating that trip physicians should be experienced in primary care.

Altitude↗
PubMed1999

Avalanche deaths in the United States: a 45-year analysis.

OBJECTIVE: To describe the demographic characteristics and patterns of death of persons killed in snow avalanches over a 45-year study period. METHODS: The national avalanche database was the source of data in this retrospective, descriptive study. RESULTS: A total of 440 victims were killed in 324 fatal avalanches, of which 87.7% were fully buried, 4.7% were partially buried, and 7.6% were not buried. The average age was 27.6 +/- 10.6 years, and 87.3% were men. Victims who died included climbers (25.5%), backcountry skiers (22.7%), out-of-bounds skiers (10.0%), snowmobilers (6.8%), in-bounds skiers (5.2%), residents (4.5%), ski patrollers (3.6%), workers (3.6%), and motorists (3.0%). Over the 45-year study period there appear to be decreases in the deaths of in-bounds skiers, highway workers, and motorists. Increasing fatalities were observed among out-of-bounds skiers, snowmobilers, ski patrollers, and backcountry skiers. Most deaths occurred in Colorado (33.0%), Washington (13.2%), and Alaska (12.0%). CONCLUSIONS: Avalanche fatalities have increased over the last 45 years. Climbers, backcountry skiers, out-of-bounds skiers, and more recently snowmobilers constitute the majority of the victims. The decrease in deaths among groups that benefit from avalanche control programs supports the benefit of avalanche prevention strategies. Further study is needed to assess the impact of avalanche safety education for individuals who travel in remote and uncontrolled terrain.

Adolescent↗
PubMed2000

In-area and backcountry snowboarding: medical and safety aspects.

Snowboarding is now a well-established winter sport and a popular mode of mountaineering. In-area and backcountry snowboarding are defined, as well as a new term, glisse, that refers to all types of skis and snowboards. New developments in equipment focus on boot and binding systems. Backcountry travel is highlighted, including ascent with snowshoes, skis, a splitboard, and crampons. Injuries are about 4-6 per 1000 snowboarding days. Upper extremity injuries are most often wrist sprains or fractures. Lower extremity injuries are primarily ankle sprains and are generally less severe than knee injuries in skiers. Fracture to the lateral process of the talus has been called snowboarder's fracture. Backcountry injuries include avalanche suffocation and trauma, deep snow immersion asphyxiation, hypothermia, frostbite, dehydration, fatigue, acute mountain sickness, and sunburn. Specific recommendations for prevention and safety are discussed.

Ankle Injuries↗
PubMed2000

Possible asphyxiation from carbon dioxide of a cross-country skier in eastern California: a deadly volcanic hazard.

This report describes an incident in which exceedingly high levels of carbon dioxide may have contributed to the death of a skier in eastern California. A cross-country skier was found dead inside a large, mostly covered snow cave, 1 day after he was reported missing. The autopsy report suggests that the skier died of acute pulmonary edema consistent with asphyxiation; carbon dioxide measurements inside the hole in which he was found reached 70%. This area is known for having a high carbon dioxide flux attributed to degassing of a large body of magma (molten rock) 10 to 20 km beneath the ski area. The literature describes many incidents of fatal carbon dioxide exposures associated with volcanic systems in other parts of the world. We believe this case represents the first reported death associated with volcanically produced carbon dioxide in the United States. Disaster and wilderness medicine specialists should be aware of and plan for this potential health hazard associated with active volcanoes.

Asphyxia↗
PubMed2002

Technological advances in avalanche survival.

Over the last decade, a proliferation of interest has emerged in the area of avalanche survival, yielding both an improved understanding of the pathophysiology of death after avalanche burial and technological advances in the development of survival equipment. The dismal survival statistics born out of the modern era of winter recreation unmistakably reveal that elapsed time and depth of burial are the most critical variables of survival and the focus of newer survival devices on the market. Although blunt trauma may kill up to one third of avalanche victims, early asphyxiation is the predominant mechanism of death, and hypothermia is rare. A survival plateau or delay in asphyxiation may be seen in those buried in respiratory communication with an air pocket until a critical accumulation of CO2 or an ice lens develops. The newest survival devices available for adjunctive protection, along with a transceiver and shovel, are the artificial air pocket device (AvaLung), the avalanche air bag system (ABS), and the Avalanche Ball. The artificial air pocket prolongs adequate respiration during snow burial and may improve survival by delaying asphyxiation. The ABS, which forces the wearer to the surface of the avalanche debris by inverse segregation to help prevent burial, has been in use in Europe for the last 10 years with an impressive track record. Finally, the Avalanche Ball is a visual locator device in the form of a spring-loaded ball attached to a tether, which is released from a fanny pack by a rip cord. Despite the excitement surrounding these novel technologies, avalanche avoidance through knowledge and conservative judgment will always be the mainstay of avalanche survival, never to be replaced by any device.

Asphyxia↗
PubMed2004

Comparison of carbon monoxide levels during heating of ice and water to boiling point with a camping stove.

OBJECTIVES: To determine whether using a camping stove to bring a pan of ice to boiling point produces higher carbon monoxide (CO) concentration than would bringing a pan of water to boiling point. The hypothesis was that ice would cause greater CO concentration because of its greater flame-cooling effect and, consequently, more incomplete combustion. METHOD: This was a randomized, prospective observational study. After an initial pilot study, CO concentration was monitored during 10 trials for each of ice and water. A partially ventilated 200-L cardboard box model was developed and then used inside a chamber at -6 degrees C. Ice temperature and volume, water temperature and volume, pan size, and flame characteristics were all standardized. Temperature of the heated medium was monitored to determine time to boiling point. Carbon monoxide concentration was monitored every 30 seconds for the first 3 minutes, then every minute until the end of each 10-minute trial. RESULTS: There was no significant difference (P > .05) in CO production levels between ice and water. Each achieved a similar mean plateau level of approximately 400 ppm CO concentration with a similar rate of rise. However, significantly higher (P = .014) CO concentration occurred at 4 and 5 minutes when the flame underwent a yellow flare; this occurred only on 3 occasions when ice was the medium. CONCLUSION: There were no significant differences for CO production between bringing a pan of ice or water to boiling point. In a small number of ice trials, the presence of a yellow flame resulted in high CO concentration. Yellow flares might occur more often with ice or snow melting, but this has not been proven.

Air Pollutants↗
PubMed2005

Gastroenteritis outbreak among mountaineers climbing the West Buttress route of Denali - Denali National Park, Alaska, June 2002.

OBJECTIVE: To determine the burden of and risk factors for diarrheal illness among mountaineers climbing Denali during the spring of 2002. METHODS: We conducted a retrospective cohort study of all willing and available climbers who returned to base camp from June 11 to 14, 2002. We used a questionnaire that addressed illness status, demographics, and potential risk factors for illness. A case of diarrhea was defined as self-reported diarrhea (loose stool) in a Denali climber who did not have diarrhea before arrival at base camp. RESULTS: Thirty-eight (29%) of the 132 climbers who were interviewed reported experiencing diarrhea at some point on the mountain. Spending 8 or more days at the 17 200-foot high camp; being a member of a climbing party in which at least 1 other person also had diarrhea, especially if tent occupancy was 3 or more; and not receiving education about disease risk-reduction techniques among climbers who were on a guided expedition were associated with increased risk of illness. CONCLUSIONS: To prevent infectious diarrheal outbreaks among mountaineers climbing Denali (and other highly trafficked alpine routes), we recommend that park staff provide climbers with detailed information related to minimizing disease risk and develop more effective strategies for preventing climbers from depositing fecal material directly into snow along the route, such as establishing and enforcing firmer penalties for noncompliance with existing human waste disposal regulations and requiring the use of personal stool-hauling devices.

Adolescent↗
PubMedDate not supplied

[Literature and medicine: the shared territory].

The text De Profundis: Valsa Lenta (De Profundis: Slow Waltz), by Portuguese author José Cardoso Pires, describing the aphasia he experienced after a stroke, was used as a starting point to study the different approaches writers and physician have regarding the disease. The differences in form and content of texts describing the disease in literature and medicine fit in the conflict between the two cultures, as described by C.P. Snow, and are typical of the increasing specialization. The addition of literary texts in training programs for doctors and health professionals may help overcome this gap, making it easier to understand the disease in its broader dimension and collaborating to improve the relationship between patients and professional.

Aphasia↗
PubMed2003

Winter activity of Ixodes scapularis (Acari: Ixodidae) and the operation of deer-targeted tick control devices in Maryland.

Host-seeking activity of adult blacklegged ticks, Ixodes scapularis Say was monitored by flagging during winter months in Beltsville, MD. Ticks were active many days during January and February, the coldest months, with some captures made when there was 70% snow cover and temperatures as low as -2 degrees C. Substantial numbers (70-90 ticks/h of flagging) of adult I. scapularis were captured on favorable days in January and February. The cost to treat white-tailed deer, Odocoileus virginianus (Zimmermann), using '4-poster' deer self-treatment devices, was estimated on a per female tick basis. We estimated deer abundance and tick attachment rates using data from the literature, tick activity levels using weather data and drag counts of ticks, and costs to operate the devices from experience. We found that self-treatment devices need not be operated continuously from late December until the third week of February. On average, savings of half the operating costs would be realized by not operating the devices when tick activity was low.

Animals↗
PubMed2004

Evidence of avian pneumovirus spread beyond Minnesota among wild and domestic birds in central North America.

To detect avian pneumovirus (APV) in central North America, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of APV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), whereas serum samples from domestic turkeys were analyzed for APV antibodies by enzyme-linked immunosorbent assay (ELISA). In 2002, the seroprevalence of disease in domestic turkeys in Minnesota remained high (42.3% of the flocks). In addition, there is evidence the disease has spread to turkey flocks in North Dakota (8.2%), South Dakota (7%), Iowa (10%), and Wisconsin (8.6%) as detected by RT-PCR and/or ELISA. House sparrows and ring-billed gulls sampled in Minnesota and snow geese from Saskatchewan, Canada, were found to harbor APV RNA. Sequence analysis of wild bird APV strains showed high amino acid sequence identity among wild bird isolates (<97%) and between wild bird and turkey viral isolates (93.2%-99.3%). This study demonstrated that APV infections were present in domestic turkey flocks and wild birds outside the state of Minnesota; however, the role of wild birds in spreading APV to domestic turkeys remains unclear.

Amino Acid Sequence↗
PubMed2004

Effects of porcine zona pellucida immunocontraceptives in zoo felids.

Methods of contraception are necessary for management of zoo felids; however, the most commonly used contraceptive (melengestrol acetate implant) is associated with serious adverse reactions with long-term use. Porcine zona pellucida (pZP) vaccines are promising as contraceptives, but their safety in zoo felids has not been tested. pZP vaccine was administered to 27 female felids representing 10 species, including African lion (Panthera leo), Asian leopard (P. pardus), jaguar (P. onca), tiger (P. tigris), snow leopard (P. uncia), cougar (Felis concolor), Siberian lynx (F. lynx), Canada lynx (F. canadensis), serval (F. serval), and bobcat (F. rufus), in 15 facilities. Over 6 wk, each animal received three i.m. injections of 65 microg pZP with Freund's complete adjuvant (FCA), Freund's incomplete adjuvant, or carbopol as the adjuvant. Behavioral signs of estrus were seen in 14 of the vaccinated felids. An unacceptably high incidence of adverse reactions was seen including injection site swelling, lameness, limb swelling, or abscessation (or all) in five felids after injection with FCA as the initial adjuvant. Adverse behavioral signs, including increased irritability and aggression, were seen in four felids. Six of the felids were assayed for antibodies against pZP during the 12 mo after vaccination; all showed antibody production. Antibody levels appeared to peak 1-4 mo after vaccination began, although elevated antibody levels persisted in two animals for > 12 mo after the first injection. All vaccinated felids were ovariohysterectomized 3-13 mo after vaccination. Folliculogenesis was present in all treated animals, and there was no histopathologic evidence of inflammatory damage to ovaries. Contraceptive efficacy was not specifically evaluated in this study; however, two of the three felids housed with an intact male became pregnant during the study, one of which gave birth to healthy cubs.

Animals↗