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PubMed2003

Comparison of the effects of UV, H2O2/UV and gamma-irradiation processes on frozen and liquid water solutions of monochlorophenols.

The effects of UV irradiation, both in the presence and absence of hydrogen peroxide, as well as of gamma irradiation on 2- and 4-chlorophenol in a solid water ice matrix have been studied and compared to those effects known to occur in aqueous solutions. While UV photolysis (>280 nm) of monochlorophenols leads to efficient coupling reactions in ice and photosolvolysis products in liquid water; hydroxylation to chlorobenzenediols is the main pathway in the presence of H2O2 in both phases. The results show that the solute molecules accumulate in a layer surrounding the ice crystal walls during the freezing process, where they then react. The radiation chemistry of chlorophenol ice samples involves preferential coupling reactions at -78 degrees C rather than reactions with the OH radicals produced by cleavage of water molecules under the conditions employed (1 kGy h(-1)). The apparent similarities between the chemistry in the UV/H2O2-treated liquid and solid, and y-irradiated liquid and solid samples are discussed. It is suggested that the reactions of OH radicals within polycrystalline ice or snow are important natural processes that should be considered in environmental, ice-core or astrophysical research.

Journal Article↗
PubMed2005

Use of optical scatter sensors for measurement of visibility.

A study on the measurement of visibility by the use of light scattering has been carried out. The basis for the research was the optical forward-scatter sensor, Mira visibility sensor, developed and produced by Aanderaa Instruments. The focus of the study was on how to measure correct visibility at different weather situations (e.g. fog, rain, haze and snow) and how a sensor can provide information on the type of particles/drops which are causing reduced visibility. Optical scatter measurement of airborne dust was also investigated. The work includes theoretical calculations and experimental work. The correlations between scatter measurements and both visibility and the concentration of airborne dust are studied. A short introduction to the subject of visibility measurement is also included.

Air Pollutants↗
PubMed2005

Models for the adsorption of organic compounds at gas-water interfaces.

The solvation parameter model is used to characterize interactions responsible for adsorption at the gas-water interface for bulk water at 15 and 25 degrees C, snow at -6.8 degrees C, mineral-supported water films (alumina, calcium carbonate and quartz) at 15 degrees C, and dry soil at 15 degrees C. The mineral-supported water films and dry soil adsorption data are modeled at different relative humidities in the range 40-99%. The models produce satisfactory results with standard errors of the estimate of 0.12 to 0.17 for regression of the model predicted adsorption equilibrium constants against the experimental values (range for equilibrium constants -2 to -7 log units). The water surface is polar with a significant capacity for dipole-type and hydrogen-bonding interactions. In addition, it is strongly electron lone pair repulsive. Dispersion interactions favor adsorption at the water surface. Mineral-supported water films at relative humidities greater than 40% demonstrate adsorption properties similar to bulk water. The adsorption characteristics, however, depend on the relative humidity and the nature of the support. In the case of dry soil the adsorption properties at different relative humidities cannot simply be explained by adsorption of a water film covering the soil surface and the changes in adsorption characteristics with relative humidity are more complex than the mineral-supported water films.

Adsorption↗
PubMed2005

Natural abundance of Sb and Sc in pristine groundwaters, Springwater Township, Ontario, Canada, and implications for tracing contamination from landfill leachates.

Using ICP-SMS and the clean lab methods and procedures developed for determining trace element concentrations in polar snow and ice, a lower limit of detection (LOD) of 30 pg l(-1) for Sb and 5 pg l(-1) for Sc was achieved, allowing the natural abundances of Sb and Sc to be measured in pristine groundwaters. Water samples were collected from natural flows and wells between Elmvale and Wyevale in Springwater Township, Ontario, Canada. The water in this region is derived from chemical reactions between meteoric fluids and the Quaternary sediments which cover the bedrock (dolomitic limestone) to depths of more than 100 m. The chemical composition of these waters (pH 8) is primarily a reflection of reactions between the percolating fluids with calcite and dolomite. The maximum concentration of Sb was 5.0 ng l(-1), and the average of all samples collected was 2.2 +/- 1.2 ng l(-1) (n = 34). The average concentration of Sc was 8.6 +/- 4.7 ng l(-1) (n = 28). The paucity of published Sb concentration data available for comparison is probably because most of the analytical methods commonly used to date, including GFAAS, HG-AAS, HG-AFS, INAA, and ICP-QMS, have lower limits of detection which are inadequate for reliably determining the natural abundance of Sb in many uncontaminated groundwaters. Also, the measurement of extremely low concentrations of Sb requires extra care to avoid possible contamination. Given the extensive use of Sb in plastics, we show that some of the containers used to collect and store samples, and for handling and preparing samples for chemical analyses, may be important sources of contamination in the laboratory. The Sb and Sc concentrations reported here should serve as reference values for this region, against which contamination by various human impacts in future could be compared.

Antimony↗
PubMed2006

Contamination of Canadian and European bottled waters with antimony from PET containers.

Using clean lab methods and protocols developed for measuring Sb in polar snow and ice, we report the abundance of Sb in fifteen brands of bottled water from Canada and forty-eight from Europe. Comparison with the natural abundance of Sb in pristine groundwaters, water bottled commercially in polypropylene, analyses of source waters prior to bottling, and addition of uncontaminated groundwater to PET bottles, provides unambiguous evidence of Sb leaching from the containers. In contrast to the pristine groundwater in Ontario, Canada containing 2.2 +/- 1.2 ng l(-1) Sb, 12 brands of bottled natural waters from Canada contained 156 +/- 86 ng l(-1) and 3 brands of deionized water contained 162 +/- 30 ng l(-1); all of these were bottled in PET containers. Natural water from Ontario bottled in polypropylene contained only 8.2 +/- 0.9 ng l(-1). Comparison of three German brands of water available in both glass bottles and PET containers showed that waters bottled in PET contained up to 30 times more Sb. To confirm that the elevated Sb concentrations are due to leaching from the PET containers, water was collected in acid-cleaned LDPE bottles from a commercial source in Germany, prior to bottling; this water was found to contain 3.8 +/- 0.9 ng l(-1) Sb (n = 5), compared with the same brand of water purchased locally in PET bottles containing 359 +/- 54 ng l(-1) (n = 6). This same brand of water in PET bottles, after an additional three months of storage at room temperature, yielded 626 +/- 15 ng l(-1) Sb (n = 3). Other German brands of water in PET bottles contained 253-546 ng l(-1) Sb (n = 5). The median concentration of Sb in thirty-five brands of water bottled in PET from eleven other European countries was 343 ng l(-1) (n = 35). As an independent check of the hypothesis that Sb is leaching from PET, the pristine groundwater from Canada (containing 2.2 +/- 1.2 ng l(-1) Sb) was collected from the source using PET bottles from Germany: this water contained 50 +/- 17 ng l(-1) Sb (n = 2) after only 37 days, even though it was stored in the refrigerator, and 566 ng l(-1) after six months storage at room temperature.

Antimony↗
PubMed2001

Incidence and geographical distribution of sudden infant death syndrome in relation to content of nitrate in drinking water and groundwater levels.

BACKGROUND: Previous studies indicate that the enteral bacterial urease is inhibited in victims of sudden infant death syndrome (SIDS). One possible inhibitor of this bacterial activity is nitrate. If ambient pollution by nitrate is involved in the etiology of SIDS only a fraction of the nitrate concentration not infrequently found in drinking water would be enough for this inhibition. METHODS: Occurrence of SIDS (n = 636) in Sweden during the period 1990 through 1996 were analysed regarding geographical and seasonal distribution in relation to the nitrate concentration in drinking water and changes in the groundwater level. RESULTS: Both the birth rate and the incidence of SIDS decreased during the study period. One quarter of the municipalities constituting 11% of the population had no cases, the maximum incidence being 6.5 per 1000 live births. Seasonality: The northernmost parts of the country had its highest incidence when the rest of the country had its lowest incidence, and the occurrence of individual deaths was associated with the recharge of groundwater which increases its nitrate content. The local incidence of SIDS was correlated (rs = 0.34-0.87) to maximally recorded concentrations of nitrate in drinking water. CONCLUSIONS: The seasonal distribution of SIDS was widely different from the south to the north of the country and seems to be associated with differences in the groundwater level changes subsequent to precipitation, frost penetration, and melting of snow. Use of drinking water with high peak concentrations or great variations in nitrate concentration was correlated to the incidence of SIDS.

Humans↗
PubMed2001

The well-being of gays, lesbians and bisexuals in Botswana.

AIMS: To investigate the level of well-being of gays, lesbians and bisexuals (GLBs) in Botswana, how this level of well-being could be promoted and whether their health care needs were met by health care professionals. RATIONALE: It is illegal to engage in same-sex activities in Botswana, punishable by imprisonment. Although Botswana's citizens have one of Africa's best health care systems, little is known about the health status, health care needs and general well-being of Botswana's GLBs. This survey attempted to uncover some of these potential health care needs, impacting on the GLBs' well-being. DESIGN/METHODS: The research framework adopted was the health and human rights approach, placing dignity before rights. A survey design, with structured questionnaires, was used. Snow-ball sampling techniques were used. RESULTS: Results indicated that varying degrees of distress were experienced by 64% of the GLBs in this study. The GLBs identified a need for human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) education and had concerns about their general health, discrimination against them and vulnerability to violence including sexual assaults. CONCLUSIONS: The well-being of the GLBs in Botswana was influenced by both positive internal acceptance of their sexual orientation and negative external acceptance by society. Health care professionals played insignificant roles in the promotion of GLBs' well-being, and could make greater inputs into health education efforts, and more significant contributions towards enhancing the GLBs' levels of well-being. Enhanced collaboration between health professionals and human rights activists are recommended to reduce violations of Botswana's GLBs' dignity and to improve their quality of life, including enhanced access to and utilization of health care services.

Adolescent↗
PubMed2002

Noninvasive molecular tracking of colonizing wolf (Canis lupus) packs in the western Italian Alps.

We used noninvasive methods to obtain genetic and demographic data on the wolf packs (Canis lupus), which are now recolonizing the Alps, a century after their eradication. DNA samples, extracted from presumed wolf scats collected in the western Italian Alps (Piemonte), were genotyped to determine species and sex by sequencing parts of the mitochondrial DNA (mtDNA) control-region and ZFX/ZFY genes. Individual genotypes were identified by multilocus microsatellite analyses using a multiple tubes polymerase chain reaction (PCR). The performance of the laboratory protocols was affected by the age of samples. The quality of excremental DNA extracts was higher in samples freshly collected on snow in winter than in samples that were older or collected during summer. Preliminary mtDNA screening of all samples allowed species identification and was a good predictor of further PCR performances. Wolf, and not prey, DNA targets were preferentially amplified. Allelic dropout occurred more frequently than false alleles, but the probability of false homozygote determinations was always < 0.001. A panel of six to nine microsatellites would allow identification of individual wolf genotypes, also whether related, with a probability of identity of < 0.015. Genealogical relationships among individuals could be determined reliably if the number of candidate parents was 6-8, and most of them had been sampled and correctly genotyped. Genetic data indicate that colonizing Alpine wolves originate exclusively from the Italian source population and retain a high proportion of its genetic diversity. Spatial and temporal locations of individual genotypes, and kinship analyses, suggest that two distinct packs of closely related wolves, plus some unrelated individuals, ranged in the study areas. This is in agreement with field observations.

Animals↗
PubMed2002

Molecular genecology of temperature response in Lolium perenne: 2. association of AFLP markers with ecogeography.

Improved winter hardiness is an important breeding objective in the forage grass Lolium perenne. This is a complex trait with several components, including the ability to survive and grow at low temperature, to acclimate to cold, tolerate wind, snow cover and ice encasement. Marker-assisted selection has the potential to increase the efficiency of breeding for improved cold tolerance. Here we describe a genecological approach to identifying molecular markers that are associated with adaptation to low winter temperatures. AFLP was used to assess the genetic diversity in 29 wild populations of ryegrass (Lolium perenne) representing a pan-European temperature cline in terms of their geographical origin. A further 18 populations from a temperature cline in Bulgaria were also analysed. In addition, two varieties and five populations representing parents of mapping families currently in use at IGER were included in the analysis. Principal coordinate (PCoA) and cluster analyses of the molecular marker data showed that the Bulgarian altitude cline populations could be distinguished clearly from the other populations. Two regression analyses were carried out; one to identify AFLP markers that correlated in frequency with low mean January temperature of the geographical origin of the population, and another to identify AFLP markers correlating in frequency with the cold tolerance phenotype of the populations, as determined by LT50 values in freezing tests. In the first analysis six AFLP markers showed significant type II trends with mean January temperature, and in the second analysis 28 bands had a significant univariate relationship with the LT50 value of the accessions. In steps 2 and 3 of the stepwise analysis a further 4 and 5 bands, respectively, improved the fit significantly. The results of the two types of regression analysis are discussed in relation to ecogeography and cold tolerance phenotype of the populations.

Ecology↗
PubMed2002

Bilateral eyelid agenesis repair in a captive Texas cougar.

Bilateral eyelid agenesis was presented with multiple ocular anomalies in a captive Texas cougar (Felis concolor). Corneal exposure resulted in substantial keratoconjunctivitis and blepharospasm. Bilateral inferopapillary fundic colobomas, persistent pupillary membranes, and an atypical iris coloboma OD were present. Surgical repair with a rotational pedicle flap resulted in functionally effective eyelids. Trichiasis was later treated with cryotherapy. Eyelid agenesis is reported infrequently in domestic cats and among large felids has only been reported in the snow leopard.

Animals↗
PubMed2002

An unusual metallic foreign body in the lateral tibiofemoral compartment.

A child presented with pain and swelling of the knee caused by a fall on the snow. Medical imaging showed an unusual metallic foreign body in the lateral tibiofemoral compartment. Arthroscopy revealed the nature of the foreign body; a metallic piece of stone had penetrated skin and cartilage and was fastened in the cartilage of the lateral femoral condyle where it caused damage to the cartilage and the anterior horn of the lateral meniscus. A partial meniscectomy was performed.

Arthroscopy↗
PubMed1999

Diagnostic efficacy of polymerase chain reaction in granulomatous uveitis.

SETTING: The granulomatous uveitis, multifocal choroiditis and periphlebitis have been suspected to be of tubercular origin but no definitive reports about detection of etiological agents have been documented in the literature. Conventional bacteriological methods are not generally helpful in diagnosing ocular tuberculosis due to difficulty with potential morbidity associated with obtaining the biopsy material from the eye. Thus, the diagnosis of ocular tuberculosis is most often presumptive. OBJECTIVE: We evaluated the role of polymerase chain reaction (PCR) for detection of Mycobacterium tuberculosis in the aqueous humor samples obtained from eyes with active uveitis. METHODS: Aqueous samples from 53 patients having cellular reaction in the anterior chamber along with any one or more of the following: 1) active vasculitis; 2) anterior vitreous cells; 3) snowball opacities; 4) snow banking in the pars plana; 5) retinochoroiditis were withdrawn by anterior chamber paracentesis and subjected to PCR. Seventeen samples from patients with definite clinical diagnoses other than tuberculosis formed a disease control group. Fifteen aqueous samples obtained from healthy subjects undergoing routine cataract surgery served as healthy controls. PCR was performed using primers capable of amplifying a 150 b.p. segment from a conserved repetitive sequence in the genome of M. tuberculosis. RESULTS: Twenty out of the 53 samples (37.7%) in the study group were positive where as only one sample out of 17 in the disease control group (5.7%) showed a weakly positive band. No sample from the healthy control group showed a positive PCR. CONCLUSION: Our study shows that PCR can be effectively used for the diagnosis of intraocular tuberculosis in the presence of uveitis.

Aqueous Humor↗
PubMed2004

[Hypothenar hammer syndrome as a cause of severe digital ischemia].

HISTORY AND CLINICAL FINDINGS: A 69-year-old amateur carpenter complained of a sudden stabbing pain and a white discoloration of D4 and D5 of the right hand while shoveling snow. On admission in our clinic twelve days later, clinical inspection showed a gangrene of the distal bone of D5 and proximal garland-shaped radial and ulnar subcutaneous haemorrhage and already ischemic contracture. D4 showed pale livid colour. INVESTIGATIONS: According to the results of an arteriography acral pulse oscillography revealed a occlusion of the digital arteries. Duplex sonography showed a thrombotic occluded aneurysm of the right ulnar artery over the hypothenar area. DIAGNOSIS: Hypothenar hammer syndrome with a thrombotic occlusion of an aneurysm of the distal ulnar artery and multiple thromboembolic occlusions of the digital arteries of D4 and D5 of the right hand. TREATMENT AND COURSE: After initial therapy with Iloprost, treatment of pain and local treatment, an intraarterial locoregional lysis therapy with urokinase was performed. Acral blood circulation improved significantly and the patient was completely painless after treatment. CONCLUSION: In case of an acute onset of unilateral digital ischemia hypothenar hammer syndrome should be considered. Regional thrombolysis can be performed in case of severe digital ischemia.

Acute Disease↗
PubMed2006

Timing of reproductive and vegetative development in Saxifraga oppositifolia in an alpine and a subnival climate.

Morphogenesis of floral structures, dynamics of reproductive development from floral initiation until fruit maturation, and leaf turnover in vegetative short-stem shoots of Saxifraga oppositifolia were studied in three consecutive years at an alpine site (2300 m) and at an early- and late-thawing subnival site (2650 m) in the Austrian Alps. Marked differences in the timing and progression of reproductive and vegetative development occurred: individuals of the alpine population required a four-month growing season to complete reproductive development and initiate new flower buds, whereas later thawing individuals from the subnival sites attained the same structural and functional state within only two and a half months. Reproductive and vegetative development were not strictly correlated because timing of flowering, seed development, and shoot growth depended mainly on the date of snowmelt, whereas the initiation of flower primordia was evidently controlled by photoperiod. Floral induction occurred during June and July, from which a critical day length for primary floral induction of about 15 h could be inferred. Preformed flower buds overwinter in a pre-meiotic state and meiosis starts immediately after snowmelt in spring. Vegetative short-stem shoots performed a full leaf turnover within a growing season: 16 (+/-0.8 SE) new leaves per shoot developed in alpine and early-thawing subnival individuals and 12 (+/-1.2 SE) leaves in late-thawing subnival individuals. New leaf primordia emerged continuously from snowmelt until late autumn, even when plants were temporarily covered with snow. Differences in the developmental dynamics between the alpine and subnival population were independent of site temperatures, and are probably the result of ecotypic adaptation to differences in growing season length.

Adaptation, Physiological↗
PubMed2006

[Malignant mesothelioma of the testes].

INTRODUCTION: Malignant mesothelioma of the tunica vaginalis is a very rare malignant tumour. The prevalence of mesothelioma is about 1 : 1 000 000: Only 1 % have their origin in the tunica vaginalis testis with a 5-year survival of less than 5 %. About 80 cases have been reported in the literature. In 41 % of these cases exposure to asbestos for many years was determines. CASE REPORT: We report on a 76-year-old patient who presented with an atypical hydrocele testis. Intraoperatively, thickened testicular walls and an crystalline lawn adjacent to the tunica vaginalis testis were found. CONCLUSIONS: Ultrasonography showing snow flurries together with cloudy hydrocele fluid and visible crystal particles and thickened testicular walls may help to identify a mesothelioma of the testicular walls. Intraoperative frozen section and a high inguinal orchiectomy is the operative method of choice.

Aged↗
PubMed1992

The effect of Alpine mountaineering on acute erythrocyte hemolysis.

The purpose of this study was to determine whether erythrocyte hemolysis occurs during a mountain ascent over snow and ice to 3285 meters. Data were collected from six experienced recreational mountaineers, 2 females and 4 males, who participated in a six-day ice climbing seminar and peak ascent in the North Cascades mountain range of the United States. Blood samples were collected from an antecubital vein at sea level (S1), in a base camp at 1515 m prior to the summit ascent (S2), on the summit at 3285 m after 6.5 hours of climbing (S3), at base camp immediately after the descent (S4), and at sea level following a trail descent from the base camp (S5). Whole blood samples were chilled and analyzed for complete blood count including hemoglobin (Hb) concentration, hematocrit (Hct), and white blood cell count (WBC). Serum was frozen and later analyzed for serum haptoglobin (Hapt). No significant changes were found for Hct and Hb among the samples. Mean (+/- SEM) Hapt values were 125 (+/- 28), 113 (+/- 25), 100 (+/- 18), 103 (+/- 32), and 109 (+/- 23) mg.dl-1 for S1 through S5, respectively. No significant differences were found among the Hapt values. Plasma volume changes (% PVC) were calculated from Hct and Hb. Mean estimated % PVC were -4.16 (+/- 1.55), -2.54 (+/- 3.93), 7.46 (+/- 4.86), and 4.80 (+/- 3.49) percent between S1 and S2, S2 and S3, S3 and S4, and S4 and S5, respectively. Total body haptoglobin (TBH) was estimated from Hapt and % PVC in an attempt to correct for the plasma volume change effect on haptoglobin concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1999

[Injury mechanisms in windsurfing regatta].

In a retrospective study, we evaluated the injuries of 44 semi-professional competitors for the German Windsurf Cup, which were suffered from during one windsurfing season. This Cup is the national qualification tour for the annual "production fun board world championship". The subjects, participating in our study were randomly chosen. There were no surf-specific differences between the two groups. The average age was 24.63% had competitive surfing as their hobby, 37% were professional or semi-professional board sailors. The subjects surfed an average of 85 days in 1995. 23 (52%) windsurfers did not get hurt during the entire season. 21 (48%) of them got injured during the 1995 windsurf season. This is an incidence of only one injury per 174 windsurfing days. Only three windsurfers were injured during a competition. The other 18 occurred during training sessions. Most accidents happened because of an overpower situation, i.e. the sail was too big for the wind force (43%), or through negligence on the part of the windsurfer (19%). The most frequent type of the accident was the so called catapult crash (57%). The most common injuries were ligament ruptures of the lower leg (33%) and head burst wounds (19%). Compared with other competitive fun sports (e.g. snow boarding), windsurfing has a lower injury risk. In regard to the injury mechanisms, prophylactic recommendations are made.

Adolescent↗
PubMed1994

[Injuries in snowboarding--a prospective study].

180 patients with injuries effected through snowboarding were evaluated during a period of 2 1/2 months in both the hospitals and private surgeries of Oberwallis. This was done to determine the nature of the injuries and the risk factors that led to them. Snowboarders are on the average 21 years of age and only rarely over 40. One-third are women, and two-third are men. More than half are beginners with less than one week's training experience; one-fifth of the beginners met with the accident on the first "snowboard day". Over 80% of the injured said that riding mistakes and insufficient training and instruction were the cause; rarely were the conditions of the runway blamed. The accidents happened irrespective of snow and runway conditions. Accidents due to tearing of the fastenings always injured the lower extremity. Injuries of the upper and lower extremities take place in the same proportions. Injuries of the trunk and head are rare. Beginners usually injure the upper, while good snowboarders the lower extremities. The most common injuries are radius fractures, followed by ankle and knee distorsions. In the case of injuries to the lower extremities, the forward leg which is the "skating leg" or "standing leg", is affected more than 80% of the cases.

Adolescent↗