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At least 19 recordsLinked to original sources
PubMed2026

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↗
PubMed1992

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↗
PubMed1992

[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↗
PubMed2026

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↗
PubMed1979

[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↗
PubMedDate not supplied

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↗
PubMedDate not supplied

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↗
PubMed2025

Do Snow-Adapted Prey Facilitate Coexistence of the Sierra Nevada Red Fox With Sympatric Carnivores?

Specialist species in alpine ecosystems may be increasingly threatened by climate-driven habitat loss and encroachment by generalist competitors. Ecological theory predicts that niche differentiation through dietary specialisation can facilitate coexistence with generalist competitors. We quantified dietary overlap between a high-elevation specialist, the Sierra Nevada red fox (SNRF; Vulpes vulpes necator) and a widespread generalist, the coyote (Canis latrans), as well as other sympatric carnivores. We were especially interested in dietary items that were themselves specialised to alpine habitats, as we expected them to be most critical to SNRF. To characterise diet, we used DNA metabarcoding for vertebrate and plant-based food items of 789 carnivore scats collected from the sites of two SNRF populations (Lassen, Sierra Nevada). As expected for potential competitors, SNRFs exhibited substantial dietary overlap with coyotes overall. Dietary niche overlap was lower between SNRF and both bobcats (Lynx rufus) and martens (Martes caurina). Compared to coyotes, however, SNRF more frequently consumed snow-adapted prey, including white-tailed jackrabbits (Lepus townsendii) and American pika (Ochotona princeps) (SIMPER p&#x2009;&#x2264;&#x2009;0.005), especially during periods of deep snow. Whitebark pine (Pinus albicaulis; presumably seeds) also appeared more regularly in SNRF winter diets compared to coyotes. These findings support the hypothesis that co-adapted subalpine prey facilitate coexistence between specialist and generalist carnivores by increasing the competitive advantage of specialists under snowier conditions. This environment-mediated shift in competitive dynamics implies that the fates of locally adapted predator and prey may be tightly linked, an important consideration for conservation planning in alpine ecosystems.

Animals↗
PubMed1977

Isoenzyme status and genetic variability of serum esterases in the lesser snow goose, Anser caerulescens caerulescens.

A maximum of 22 bands comprising four esterase subgroups--acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase--were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. A minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. The genetic variability of these loci was calculated to be 1.25% average heterozygosity, while 14.3% of the loci were polymorphic. These estimates of genetic variability were substantially lower than those reported for other vertebrate species. The low degree of genetic variability found in snow goose serum esterases coupled with the extensive protein multiplicity observed may possibly reflect an adaptive strategy based on "biochemical plasticity" rather than genic heterozygosity for this species. The nature of evolutionary forces acting upon multiple enzyme systems such as esterases is discussed. The concept of "conditional neutrality" is introduced and defined within this context.

Animals↗
PubMed1991

Snow skiing for the physically disabled.

The sport of snow skiing by the physically disabled, which originated in Europe in 1935 and first received attention in the United States in the 1940s, is reviewed in terms of opportunities available, instructions, adaptive equipment necessary, and benefits provided. Persons with a wide variety of disabilities (such as cerebral palsy, multiple sclerosis, spinal cord injury, hemiplegia, amputation, blindness, spina bifida, and muscular dystrophy) can participate. Accordingly, a wide range of adaptive equipment is available--including outrigger skis, flip-skis, canting wedges, ski bras, "toe spreaders," sit-skis, and mono-skis--to allow safe enjoyment of the sport. Programs for instruction of the disabled skier are increasing in number and popularity, and numerous opportunities are available to enter competitive events sponsored by National Handicapped Sports. Both the participants and the instructors relate the numerous physical and psychologic benefits that can be derived from skiing; the sport provides an almost universal enjoyment of the sense of freedom and independence. Snow skiing is an enjoyable, beneficial, outdoor cold-weather activity that the disabled population can safely learn with proper instruction.

Adaptation, Physiological↗
PubMed1992

The genetic legacy of Mother Goose--phylogeographic patterns of lesser snow goose Chen caerulescens caerulescens maternal lineages.

By using the polymerase chain reaction to amplify and sequence 178 bp of a rapidly evolving region of the mtDNA genome (segment I of the control region) from 81 individuals, approximately 11% of the variation present in the lesser snow goose Chen caerulescens caerulescens L. mitochondrial genome was surveyed. The 26 types of mtDNA detected formed two distinct mitochondrial clades that differ by an average of 6.7% and are distributed across the species range. Restriction analysis of amplified fragments was then used to assign the mtDNA of an additional 29 individuals to either of these clades. Within one major clade, sequence among mtDNAs was concordant with geographic location. Within the other major clade the degree of sequence divergence among haplotypes was lower and no consistent geographic structuring was evident. The two major clades presumably result from vicariant separation of lesser snow geese during the Pleistocene.

Animals↗
PubMed2025

Variation in Severity of Symptoms Associated With Two Snow Mountain Virus Inocula.

Snow Mountain Virus (SMV), the prototype of genogroup II and genotype II Norovirus (NoV), was used in human challenge studies to examine the infectivity, pathogenicity, and immune response to NoV. Clinical and laboratory data from two previously completed SMV human challenge trials using two different inocula (primary and secondary) were analyzed to compare the infectivity, illness, viral shedding, and serum IgG conversion. The primary and secondary SMV inocula were sequenced for detecting single nucleotide mutations. Of 15 subjects challenged with the primary inoculum between 2000 and 2002, nine were infected, and seven presented with acute gastroenteritis. Of 33 subjects challenged with the secondary inoculum between 2016 and 2018, 25 were infected, and nine presented with acute gastroenteritis. There were no statistically significant differences in overall infection and illness rates between subjects challenged with the primary inoculum versus the secondary inoculum. However, subjects infected with the primary inoculum experienced more severe clinical symptoms of acute gastroenteritis, showing higher severity scores (6.00 vs. 2.94, p&#x2009;=&#x2009;0.003) compared with those infected with the secondary inoculum. We also observed that infection with the secondary inoculum resulted in longer viral shedding compared with the primary inoculum. Partial sequencing of the SMV genome identified three mutations in both inocula. Understanding the differences between these two SMV inocula is critical for NoV vaccine evaluation and using a less pathogenic inoculum for a vaccine trial will require more participants to meet the target reduction in illness when evaluating the efficacy of candidate vaccines.

Humans↗
PubMed1976

Assortative mating in lesser snow geese (Anser caerulescens).

Assortative mating occurs in the dimorphic lesser snow geese in the wild. Mixed matings between the blue and white phases are much less frequent than would be expected by chance. Evidence from marked birds in field conditions indicated that mate choice was correlated with familial color. Birds from white families usually chose white mates, birds from blue families usually chose blue mates, and birds from mixed families chose mates of either color. Similar results were obtained under captive conditions when offspring from foster families with particular parental and offspring color combinations were allowed to choose mates. Both parental color and sibling color appeared to influence mate choice. The bird's own color did not appear to be important in mate choice in either field or experimental conditions, and in those cases where male and female parents differed in color neither parental color was more influential than the other in determining offspring mate choice. The results provide the first evidence, to our knowledge, that mate selection based on familial appearance operates intraspecifically in the wild.

Animals↗
PubMed1977

G-band patterns of the Siberian snow sheep (Ovis nivicola) and their relationship to chromosomal evolution in sheep.

G-band patterns of the Siberian snow sheep, Ovis nivicola alleni, 2n=52, were compared with the patterns reported in 2n=54 wild Asiatic mouflon and 2n=54 North American sheep and those in domestic sheep with 2n=54, 53, and 52. The three largest pairs of biarmed autosomes displayed indistinguishable, presumably homologous, G-banding patterns in all types of sheep. The banding and morphology of the fourth pair of biarmed autosomes in O.nivicola differed from those of the three translocation variants described in domestic sheep. Wild sheep with 2n=54 may have evolved monophyletically from an ancestral 2n=58-56-54 population or polyphyletically by a series of independent, nonrandom fusions. In contrast, the fouth pair of biarmed autosomes in O.nivicola and in 2n=52 domestic sheep variants may have resulted from random fusions of different chromosomes.

Animals↗
PubMed1975

Virus-like particles in cystic mammary adenoma of a snow leopard.

Virus-like particles were observed in the giant cells of a mammary adenoma of a snow leopard kept in captivity. Particles that measured 115 to 125 nm in diameter budded from the lamella of endoplasmic reticulum and were studded on their inner surfaces with dense granules (approximately 12 nm) that gave them their unique ultrastructural morphology. Such particles were not observed extracellularly. Type B or type C particles were not seen in the tumor tissue.

Adenoma↗