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Unveiling microbial communities and biogeochemical cycles in Antarctic colored snow.

Snow cover, the extensive terrestrial habitat in Antarctica, sometimes exhibits vivid coloration, yet the structure and function of its microbial communities remain poorly characterized. Using metagenomic sequencing of red snow (RS) and green snow (GS) from the Fildes Peninsula, we found that bacterial, eukaryotic, and archaeal relative abundances were 85.82%, 13.52% and 0.16%, respectively. &#x3b2;-Diversity differed significantly between RS and GS across these three domains (P&#x2009;<&#x2009;0.05). Dominant bacterial phyla included Bacteroidota (RS: 62.61%; GS: 38.72%) and Pseudomonadota (RS: 32.80%; GS: 54.10%). Among eukaryotes, Chlorophyta (RS: 58.10%; GS: 52.98%) and Basidiomycota (RS: 14.80%; GS: 8.08%) were prevalent. Nanobdellota dominated archaea, with lower abundance in RS than GS. In the algal community, Sanguina, Gonium and Chloromonas were significantly enriched in red snow, while Chlorella and Micractinium were enriched in green snow (P&#x2009;<&#x2009;0.05). Marker genes associated with carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) cycles were identified in green and red snow. Aerobic respiration and phosphate regulation were significantly enriched in red snow, while CO oxidation, fermentation, and denitrification were significantly enriched in green snow. Key microbial genera associated with these functional pathways also varied. In the denitrification of red snow, Stutzerimonas was the most abundant genus, while Janthinobacterium was abundant in green snow. Nitrification-related genes were detected only in red snow based on the present metagenomic data. The network of the red snow microbial community was potentially more complex and resistant based on topology, which not only benefited its own long-term survival but might also have potentially influenced the positive feedback effect of snowmelt by maintaining a low-albedo snow surface. This provided an ecological implication under climate warming: the expansion of red snow patches showed the potential to the increase nitrate runoff export, which would affect nitrogen nutrient levels in coastal Antarctic waters. Overall, this study used metagenomics to compare the multidomain (bacteria, archaea and eukaryotes) composition and diversity between red snow and green snow, and directly linked key microbial taxa with functional genes of biogeochemical cycles. This study provided new insights into the biological characteristics and functional potential of Antarctic colored snow.

Snow

Cardiorespiratory strain during walking in snow with boots of different weights.

In order to assess the physiological strain of different boot weights, seven male and three female subjects walked on a treadmill and a snow-field while wearing three types of boots: winter jogging boots (WJB), rubber boots (RB), and rubber safety boots (RSB), weighing (means +/- s.d.) 0.9 +/- 0.1, 1.9 +/- 0.4 and 2.5 +/- 0.2 kg, respectively During each walk the subjects wore the same clothing ensembles and moved at the same, individually determined speed. The mean (+/- s.e.) depths of the footprint impression in the snow while walking in the WJB, RB, and RSB were 26.1 +/- 1.5, 25.6 +/- 1.4 and 26.1 +/- 1.5 cm (NS), respectively. During walking on the treadmill, the means for oxygen consumption were 0.79 +/- 0.05, 0.81 +/- 0.06 and 0.83 +/- 0.04 l min-1 (NS) and in snow 2.24 +/- 0.18, 2.34 +/- 0.17 and 2.34 +/- 0.19 l min-1 (p less than 0.01) with the WJB, RB and RSB, respectively. The mean oxygen consumption levels observed during the walks averaged 23% and 65% of the subject's maximum oxygen consumption on the treadmill and in the snow-field, respectively. During the walking tests the corresponding mean heart rates were 106 +/- 4, 93 +/- 5, and 95 +/- 5 beats min-1 (p less than 0.05) on the treadmill, and 151 +/- 11, 150 +/- 11 and 151 +/- 12 beats min-1 (NS) in snow. No significant differences in ratings of perceived exertion were observed between the walking tests in snow with the three types of boots. In accordance with earlier studies, walking in snow was found to be strenuous work. In conclusion, the use of the RSB is recommended during logging work in snow, since they are known to provide greater protection than lighter boots and the increase in physiological strain experienced with RSB in this study was not appreciably greater than that with boots of lighter weight.

Adolescent

Heavy metal concentrations in urban snow as an indicator of air pollution.

Manganese, Zn, Pb, Cu, Cr and Cd concentrations in snow collected in and around urban areas and from snow dumping stations in Hokkaido were determined by Zeeman-type atomic absorption spectrophotometry. We compared the heavy metal concentrations in the snow with background levels to see whether they could be used as an effective indicator of urban air pollution. The heavy metal concentrations in the snow clearly increased towards the center of the city of Sapporo; they were influenced by local pollution in the industrial area of the city and by the effect of the seasonal wind from the northwest. In the cities, we found the greatest influence on heavy metal concentrations was air pollution caused by industrial activities. The elemental concentrations in urban snow were from several to tens of times higher than background levels. The mean concentrations of the elements studied were in the order Mn greater than Zn greater than Pb greater than Cu greater than Cr greater than Cd, the same as in water except for Pb. We propose that data on trace metal concentrations in snow are a reliable guide to the degree of air pollution, and can be used as a simple and effective indicator of urban air pollution.

Air Pollution

IgE sensitization in snow crab-processing workers.

Occupational asthma is a highly prevalent disease among snow crab-processing workers, but its immunologic mechanism has not been identified. Prick skin tests with snow crab-meat extract, commercial extracts from other crab genera, and snow crab cooking water collected in 1984 were performed on 119 workers. Crab-specific IgE was assessed by RAST in sera from 115 workers with meat and water extracts. Both skin and RAST tests were performed in 58 individuals. Diagnosis of occupational asthma had previously been confirmed in 54 individuals. A highly significant relationship was demonstrated between the presence of immediate skin reactivity or increased serum levels of specific IgE to crab extracts and the occurrence of occupational asthma. There was good agreement between the results of skin and RAST tests with extracts of either meat or snow crab cooking water. Cooking water and snow crab-meat extracts were more sensitive than commercial preparations. Water extract was more potent and more sensitive than meat extract. We conclude that there is evidence that occupational asthma in snow crab-processing workers is mediated through an IgE mechanism.

Aerosols

Effect of age and coronary artery disease on response to snow shoveling.

OBJECTIVES: The objective of this study was to evaluate the effect of age and coronary artery disease on responses to snow shoveling. BACKGROUND: Little information is available on the hemodynamic and metabolic responses to snow shoveling. METHODS: Sixteen men with asymptomatic coronary artery disease and relatively good functional work capacity, 13 older normal men and 12 younger normal men shoveled snow at a self-paced rate. Oxygen consumption, heart rate and blood pressure were determined. In nine men with coronary artery disease left ventricular ejection fraction was evaluated with an ambulatory radionuclide recorder. RESULTS: Oxygen consumption during snow shoveling differed (p < 0.05) among groups; it was lowest (18.5 +/- 0.8 ml/kg per min) in those with coronary artery disease, intermediate (22.2 +/- 0.9 ml/kg/min) in older normal men and highest (25.6 +/- 1.3 ml/kg/min) in younger normal men. Percent peak treadmill oxygen consumption and heart rate with shoveling in the three groups ranged from 60% to 68% and 75% to 78%, respectively. Left ventricular ejection fraction and frequency of arrhythmias during shoveling were similar to those during treadmill testing. CONCLUSIONS: During snow shoveling 1) the rate of energy expenditure selected varied in relation to each man's peak oxygen consumption; 2) older and younger normal men and asymptomatic men with coronary artery disease paced themselves at similar relative work intensities; 3) the work intensity selected represented hard work but was within commonly recommended criteria for aerobic exercise training; and 4) arrhythmias and left ventricular ejection fraction were similar to those associated with dynamic exercise.

Adult

[Snow-white in danger. Women, socialization and health. Some messages, by means of allegory].

This is the modern-day allegory of Snow White, the most beautiful woman in the kingdom. Because of her beauty she is banished from the castle. The seven dwarfs who befriend her welcome her into their cottage. Little by little, they begin to impose their demands on her. They try to coerce her into submitting to life's little demands in order to attain beauty, health and happiness. Diet categorizes the foods filled with nasty calories that Snow White must learn to do without. Fitness outlines her spare time exercise regimen to keep her slim and trim. Mr. Clean provides her with specific household cleaning tips. Job tips advise her how to get a job outside the home to maintain her financial autonomy. Pills provide her with a way to assure a smooth transition between work and the household chores. Oh! And we almost forgot Baby. Who will care for Baby? Snow White of course--since she is the only woman in the house. Finally, to assure perfect co-ordination of all these tasks, Excel sends her off to take a time management course. Snow white responds enthusiastically to all the expectations. As anticipated, she loses weight. She then becomes exhausted and collapses and is transformed into Burnt-Out Beauty. She remains in a deep sleep for 100 days and nights. The dwarfs place her in a glass box in a forest clearing where she is discovered by Prince Conscience. He opens the glass box, kisses her lightly on the forehead, and immediately disappears. Snow White awakens and remembers the events preceding her deep sleep.(ABSTRACT TRUNCATED AT 250 WORDS)

Female

A chromosome-level assembly of the alpine snow alga Chloromonas typhlos.

Chloromonas typhlos is a cosmopolitan alpine snow alga distributed across continents, and its blooming accelerates snow melting by decreasing the amount of snow albedo. To elucidate the genetic traits underlying the adaptation of C. typhlos to the alpine habitat, we combined PacBio sequencing and Hi-C to generate a high-quality chromosome-level genome assembly (contig N50: 1.29&#x2009;Mb; scaffold N50: 7.23&#x2009;Mb) with 31 chromosomes and a genome size of 200.86&#x2009;Mb. Repetitive elements constituted 11.05% of the genome, and 16,133 protein-coding genes were predicted, of which 82% were functionally annotated. This study provides a set of omics resources both for snow algae and the genus Chloromonas.

Snow

[Studies on medico-legal diagnosis in cold district. 5. The blood shed on the snow (author's transl)].

By using bovine blood as a model, the authors have observed the forms and patterns of the blood drops shed or spurted on the snow and the extent of a large amount of blood absorbed in the deep snows, investigating the influence of the properties of snow upon them. It has been demonstrated that the polarographic method is most excellent for the purpose of determining the amount of blood absorbed in the snow.

Animals

John Snow and research.

John Snow's leadership in epidemiology as well as anaesthesia resulted from his research as much as his clinical practice. In anaesthesia, Snow's research concerned the regulation of concentrations of volatile agents and the development of efficient inhalers; the uptake and elimination of volatile agents; stages of anaesthesia; carbon dioxide metabolism and rebreathing; and metabolism in anaesthesia and the theory of anaesthesia. In epidemiology, Snow investigated the relationship of water supplies to mortality in cholera during the London epidemic in 1854, which led him to formulate an original and valid theory of the transmission of cholera. Snow's research, which has received less attention than anecdotes concerning his career (e.g., his anaesthetizing Queen Victoria and urging removal of the handle of a contaminated water pump), was always directed towards solving specific problems. The significance of his research is evident in its leading not only to improvements in health care but also to the evolution of anaesthesia and epidemiology as professional disciplines.

Anesthesia, Inhalation

Snow Mountain agent gastroenteritis from clams.

A 1983 investigation of two clambake-related gastroenteritis outbreaks in Rochester, New York, showed that 84 (43%) of 196 persons interviewed had an acute illness characterized by watery diarrhea, vomiting, and abdominal cramps. None of the ill persons were hospitalized or had complications. Illness was associated with eating raw (p = 0.002) or baked (p less than 0.01) hard-shell clams, with the risk of illness increasing with the total number of clams consumed (p less than 0.01). The median incubation period and duration of illness were 36 and 44 hours, respectively. Stool samples obtained 2-4 days after onset of illness were negative for commonly recognized bacterial and viral pathogens. However, of 31 persons whose stools were tested, the stool of only one ill person was positive by enzyme-linked immunosorbent assay for the Snow Mountain agent, one of the Norwalk-like viruses. Paired serum specimens from six (67%) of nine ill and two (29%) of seven well persons showed a fourfold or greater rise in antibody titer to Snow Mountain agent. Persons who ate clams were more likely to seroconvert to Snow Mountain agent (eight of 12) than were those who did not eat clams (zero of four) (p = 0.04). The clams were harvested off the coast of southern Massachusetts in late October, when harvest waters were documented to be contaminated by untreated municipal sewage. This report describes the first documented outbreak of shellfish-associated gastroenteritis attributed to Snow Mountain agent of which we are aware.

Acute Disease

Who made John Snow a hero?

This paper describes how and why John Snow's investigation of the transmission of cholera grew into an epidemiologic classic. The evolution of the interpretation of the work of John Snow was first studied in depth in the Dutch medical literature, and thereafter traced more superficially in the bacteriologic, hygienic, and epidemiologic literature of Germany, the United Kingdom, and the United States. From the oral tradition of teaching, as well as from the written sources, it is concluded that US epidemiologist W. H. Frost was responsible for the revival of the work of John Snow in the 1930s. Besides the obvious and enjoyable clarity of thinking and reasoning, epidemiologically and medically, of the writings of John Snow, his example well suited epidemiology of the 1930s since his convictions came very close to the bacteriologic paradigm of the day.

Cholera

Injuries from single-vehicle crashes and snow depth.

Swedish official statistics on road traffic accidents shows a remarkable variability among different winter seasons in single-vehicle crashes resulting in personal injuries--one of the major causes of personal injury in road traffic. This study presents results from analyses investigating the role played by snow as an injury-reducing factor. The regression model specified implies, when applied to Swedish data, that an increase in snow depth by 1 cm--for snow depths less than 40 centimetres--reduces the number of crashes with occupant injury by 3%. This finding has implications for assessing trends in traffic safety through the use of routine statistics on motor vehicle occupant injuries and also shows that roadside design is a decisive factor in the generation of injury to the individual in single-vehicle crashes.

Accidents, Traffic

Lead contamination of urban snow.

Lead content of newly fallen snow in an urban area ranges from 34 to 56 ppb. After falling, snow may incorporate major additional amounts of lead by dry deposition of lead aerosols from local sources. The highest concentration found was 2,700 ppb. Ingestion of lead-contaminated snow might pose a health hazard to inner city children.

Lead

Parasuicidal snow-wandering in Arctic northern Norway.

Psychiatric morbidity in the Arctic has not been extensively studied. Seasonal variations in climate, light and darkness are unique for these areas and impose special kinds of strains on the population. Three case-histories focusing on snow-wandering as a parasuicidal act are presented. One of them bears some resemblance to the Arctic hysteria described among Eskimoes. Reasons for choosing snow-wandering as an alternative to other kinds of suicide are discussed and a hypothesis is suggested. The psychological and physiological factors as explanations for post snow-wandering amnesia are discussed.

Adult

Foodborne Snow Mountain agent gastroenteritis with secondary person-to-person spread in a retirement community.

A variety of small round-structured viruses are being recognized with increasing frequency as a cause of gastroenteritis in the community, but have rarely been reported to cause outbreaks in hospitals or extended-care facilities. From March 20 through April 15, 1988, an outbreak of gastroenteritis occurred in a retirement facility in the San Francisco Bay area. Illness was characterized by diarrhea, nausea, and vomiting; two residents died. Attack rates were 46% (155 of 336) in residents and 37% (28 of 75) in employees. During the initial outbreak period, illness among residents was associated with two shrimp meals served in the facility dining hall (odds ratio = 6.7). Person-to-person transmission probably occurred: The risk of becoming ill one or two days after a roommate became ill was significantly greater than that of becoming ill at other times during the outbreak (risk ratio = 6.5). Microbiologic examinations for bacterial and parasitic enteric pathogens were negative; however, 27-nm viral particles were detected by immune electron microscopy and by blocking enzyme immunoassay to Snow Mountain agent in stools obtained at the onset of illness from one of six ill residents. Seroconversion (greater than fourfold antibody rise) to Snow Mountain agent was detected in acute- and convalescent-phase serum specimens from five of six ill residents as measured by enzyme immunoassay, but not for Norwalk agent as measured by radioimmunoassay. This report of an outbreak of Snow Mountain agent gastroenteritis in an extended-care facility documents that these difficult-to-identify 27-nm viruses can cause outbreaks in inpatient settings.

Aged

The Wood Library-Museum's 1858 edition of John Snow's On chloroform and other anaesthetics.

The original 1858 edition of John Snow's On Chloroform and Other Anaesthetics, from which came the Wood Library-Museum of Anesthesiology reprints in 1971 and 1989, was donated to the Wood Library-Museum by Ralph Waters of Madison, Wisconsin, in 1967. The book contains a message of appreciation to Waters, dated October 1937, with the signatures of J. Blomfield, Charles King, and R.R. Macintosh as representatives of anesthesiology in England. Correspondence exists in the archives of the University of Wisconsin-Madison between Macintosh, Professor of Anaesthetics in Oxford, and Waters, Associate Professor in Madison. This reveals that Waters, during his visit to England in 1936, inspired British anesthetists to discover more of Snow's early contributions to anesthesiology, even though Waters himself did not possess On Chloroform and Other Anaesthetics. King, a manufacturer of anesthetic equipment, found a copy in the hands of Blomfield, an anesthetist at St. George's Hospital, London, where John Snow had worked. It was this copy that they presented to Waters, and that was delivered to Waters by hand when Waters' resident, Ivan Taylor, returned from Oxford to Madison. Blomfield's ownership of the book, in addition to his position as president of the Association of Anaesthetists of Great Britain and Ireland, explains why the inscription is in his handwriting.

Anesthesiology

Fluoride in treated sewage and in rain and snow.

The liquid effluent of a sewage treatment plan contained 1.21 ppm ionic and total fluoride, which was higher than 1.0 ppm fluoride in the fluoridated public water supply. The discharge of the effluent into a river did not greatly raise the fluoride content of the river water because of dilution and other factors. The semisolid waste of sewage treatment also contained fluoride, but very little was volatilized on burning. Rain and snow were found to contain detectable quantities of fluoride, and the fluoride content of snow increased markedly during exposure to an urban environment.

Fluorides