scholarly journals Survival of halophilic Archaea in Earth's cold stratosphere

2016 ◽  
Vol 16 (4) ◽  
pp. 321-327 ◽  
Author(s):  
P. DasSarma ◽  
V.J. Laye ◽  
J. Harvey ◽  
C. Reid ◽  
J. Shultz ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Cold Adaptation ◽  
Halophilic Archaea ◽  
Cold Temperature ◽  
Freezing And Thawing ◽  
Cold Adapted ◽  
Liquid Cultures ◽  
Genome Wide ◽  
Temperature Exposure ◽  
Genetic Responses

AbstractHalophilic Archaea are known to tolerate multiple extreme conditions on Earth and have been proposed as models for astrobiology. In order to assess the importance of cold-adaptation of these microorganisms in surviving stratospheric conditions, we launched live, liquid cultures of two species, the mesophilic model Halobacterium sp. NRC-1 and the cold-adapted Antarctic isolate Halorubrum lacusprofundi ATCC 49239, on helium balloons. After return to Earth, the cold-adapted species showed nearly complete survival while the mesophilic species exhibited slightly reduced viability. Parallel studies found that the cold-adapted species was also better able to survive freezing and thawing in the laboratory. Genome-wide transcriptomic analysis was used to compare the two haloarchaea at optimum growth temperatures versus low temperatures supporting growth. The cold-adapted species displayed perturbation of a majority of genes upon cold temperature exposure, divided evenly between up-regulated and down-regulated genes, while the mesophile exhibited perturbation of only a fifth of its genes, with nearly two-thirds being down-regulated. These results underscore the importance of genetic responses of H. lacusprofundi to cold temperature for enhanced survival in the stratosphere.

Histological aspects of the cryopreservation of potato

2008 ◽  
Vol 56 (3) ◽  
pp. 341-348
Author(s):  
P. Pepó ◽  
A. Kovács
Keyword(s):  
Cell Wall ◽  
Low Temperatures ◽  
Cell Walls ◽  
Cellular Level ◽  
Adaptive Mechanism ◽  
Epidermal Layer ◽  
Freezing And Thawing ◽  
Meristematic Cells ◽  
Suitable Solution ◽  
Vacuolated Cells

Cryopreservation appears to be a suitable solution for the maintenance of potato germplasms. The protocol described in this paper can be applied for the vitrification and preservation of meristems. During histo-cytological studies it is possible to observe modifications at the cellular level and to understand the adaptive mechanism to low temperatures. Control potato meristem tissue contained a number of meristematic cells with a gradient of differentiation. After freezing there were a large number of vacuolated cells, some of which exhibited broken cell walls and plasmolysis. The thickening of the cell wall, giving them a sinuous appearance, was observed after freezing and thawing the meristems, with ruptures of the cuticle and epidermal layer.

Low Temperature Fault Isolation Using Soft Defect Localization

2012 ◽  
Author(s):  
Kristopher D. Staller
Keyword(s):  
Low Temperatures ◽  
Laser Scanning ◽  
Low Cost ◽  
Fault Isolation ◽  
Laser Scanning Microscopy ◽  
Cold Temperature ◽  
Multiple Point ◽  
Defect Localization ◽  
Low Levels

Abstract Cold temperature failures are often difficult to resolve, especially those at extreme low levels (< -40°C). Momentary application of chill spray can confirm the failure mode, but is impractical during photoemission microscopy (PEM), laser scanning microscopy (LSM), and multiple point microprobing. This paper will examine relatively low-cost cold temperature systems that can hold samples at steady state extreme low temperatures and describe a case study where a cold temperature stage was combined with LSM soft defect localization (SDL) to rapidly identify the cause of a complex cold temperature failure mechanism.

Strategies and adaptations to aquatic life at high altitude

2017 ◽  
Author(s):  
Dean Jacobsen ◽  
Olivier Dangles
Keyword(s):  
High Altitude ◽  
Environmental Conditions ◽  
Low Temperatures ◽  
Cold Adaptation ◽  
Inorganic Carbon ◽  
Direct Result ◽  
Aquatic Life ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Regulatory Capacity

Chapter 5 is focused on how organisms cope with the environmental conditions that are a direct result of high altitude. Organisms reveal a number of fascinating ways of dealing with a life at high altitude; for example, avoidance and pigmentation as protection against damaging high levels of ultraviolet radiation, accumulation of antifreeze proteins, and metabolic cold adaptation among species encountering low temperatures with the risk of freezing, oxy-regulatory capacity in animals due to low availability of oxygen, and root uptake from the sediment of inorganic carbon by plants living in waters poor in dissolved carbon dioxide. These and more adaptations are carefully described through a number of examples from famous flagship species in addition to the less well-known ones. Harsh environmental conditions work as an environmental filter that only allows the well-adapted species to slip through to colonize high altitude waters.

Increased ACTH response to corticotropin-releasing factor in cold-adapted rats in vivo

1989 ◽  
Vol 257 (3) ◽  
pp. E336-E339 ◽  
Author(s):  
A. Uehara ◽  
Y. Habara ◽  
A. Kuroshima ◽  
C. Sekiya ◽  
Y. Takasugi ◽  
...  
Keyword(s):  
Stress Responses ◽  
Cold Adaptation ◽  
Corticotropin Releasing Factor ◽  
Plasma Acth ◽  
Cold Adapted ◽  
Repeated Restraint Stress ◽  
Cross Adaptation ◽  
Freely Moving ◽  
Increased Activity

We have recently reported that chronically repeated restraint stress results in improved cold tolerance in rats via an increased activity of nonshivering thermogenesis, a characteristic metabolic change observed during cold adaptation, suggesting the presence of cross-adaptation between cold and stress. It is well established that the hypothalamic-pituitary-adrenal (HPA) axis is activated in various stress responses. In the present study, therefore, we examined whether cold adaptation would alter the adrenocorticotropic hormone (ACTH)-releasing state in vivo using freely moving, conscious rats chronically implanted with intra-atrial cannulas. There was no difference in the basal levels of plasma ACTH between warm control and cold-adapted rats. On the other hand, the ACTH response to the intravenous administration of corticotropin-releasing factor (CRF; 2 micrograms/animal) was significantly elevated in cold-adapted rats. However, the injection of 10 micrograms of CRF, which was considered as a dose to elicit the maximal ACTH response, resulted in similar ACTH release patterns between the two groups. These changes in the responsiveness of ACTH secretion have been observed in rats chronically exposed to stressful conditions. The results demonstrated in the present study, therefore, provide further evidence for our hypothesis that there may exist cross-adaptation between cold and nonthermal stress.

The Effects of Thyroxine and Isopropylnoradrenaline on Cytochrome Oxidase Activity in Brown Adipose Tissue

1973 ◽  
Vol 51 (10) ◽  
pp. 751-758 ◽  
Author(s):  
H. M. C. Heick ◽  
C. Vachon ◽  
Mary Ann Kallai ◽  
Nicole Bégin-Heick ◽  
J. LeBlanc
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Protein Content ◽  
Cytochrome Oxidase ◽  
Cold Adaptation ◽  
Metabolic Response ◽  
Mitochondrial Enzymes ◽  
Cold Adapted ◽  
Brown Adipose ◽  
Hormonal Treatments

Groups of animals were treated with injections of isopropylnoradrenaline, thyroxine, or both hormones together. The effects of these hormonal treatments on the size, protein content, and level of some mitochondrial enzymes, in particular the cytochrome oxidase, were determined and compared to the effect on these parameters produced by cold adaptation. The changes observed were correlated with the resistance of the animals to cold stress and with their metabolic response to injections of isopropylnoradrenaline. All treatments increased the size of the brown adipose tissue. Whereas thyroxine had little effect on the protein content and cytochrome oxidase, both isopropylnoradrenaline and cold adaptation produced increases in these parameters. It appears that the isopropylnoradrenaline-treated animals mimic more closely the cold-adapted animals than do those with thyroxine treatment. However, the isopropylnoradrenaline-treated animals are not as resistant to cold as the cold-adapted animals.

Structural changes in acclimated and unacclimated leaves during freezing and thawing

2004 ◽  
Vol 31 (1) ◽  
pp. 29 ◽  
Author(s):  
Marilyn C. Ball ◽  
Martin J. Canny ◽  
Chen X. Huang ◽  
Roger D. Heady
Keyword(s):  
Low Temperatures ◽  
Structural Changes ◽  
Living Cells ◽  
Evolutionary Significance ◽  
Intercellular Spaces ◽  
Freezing And Thawing ◽  
Specific Expansion ◽  
Intracellular Ice ◽  
Leaf Tissues ◽  
Leaf Survival

Freeze-induced damage to leaf tissues was studied at different states of acclimation to low temperatures in snow gum, Eucalyptus pauciflora Sieber ex Sprengel. Intact, attached leaves of plants grown under glasshouse or field conditions were frozen at natural rates (frost-freezing) and thawed under laboratory conditions. Leaves were cryo-fixed unfrozen, during frost-freezing or after thawing for observation in a cryo-scanning electron microscope. Frost-freezing in unacclimated tissues caused irreversible tissue damage consistent with tissue death. Intracellular ice formed in the cambium and phloem, killing the cells and leaving persistent gaps between xylem and phloem. Many other cells were damaged by frost-freeze-induced dehydration and failed to resorb water from thawed extracellular ice, leaving substantial amounts of liquid water in intercellular spaces. In contrast, acclimated leaves showed reversible tissue displacements consistent with leaf survival. In these leaves during freezing, massive extracellular ice formed in specific expansion zones within the midvein. On thawing, water was resorbed by living cells, restoring the original tissue shapes. Possible evolutionary significance of these expansion zones is discussed. Acclimated leaves showed no evidence of intracellular freezing, nor tissue lesions caused by extracellular ice. While the observations accord with current views of freeze-sensitivity and tolerance, cryo-microscopy revealed diverse responses in different tissue types.

scholarly journals Genome-Wide Analysis of Cold Adaptation in Indigenous Siberian Populations

PLoS ONE ◽  
2014 ◽  
Vol 9 (5) ◽  
pp. e98076 ◽  
Author(s):  
Alexia Cardona ◽  
Luca Pagani ◽  
Tiago Antao ◽  
Daniel J. Lawson ◽  
Christina A. Eichstaedt ◽  
...  
Keyword(s):  
Cold Adaptation ◽  
Genome Wide Analysis ◽  
Genome Wide

The effect of cold adaptation on kinetics of insulin and growth hormone in heifers

1993 ◽  
Vol 73 (1) ◽  
pp. 33-47 ◽  
Author(s):  
S. L. Scott ◽  
R. J. Christopherson
Keyword(s):  
Growth Hormone ◽  
Cold Adaptation ◽  
Slow Component ◽  
Plasma Concentrations ◽  
Endocrine System ◽  
Insulin Injection ◽  
Metabolic Clearance ◽  
Cold Environment ◽  
Cold Adapted ◽  
Total Turnover

Ten Holstein heifers 1 yr of age were housed in groups of five in temperature-controlled environmental chambers maintained at either 20 °C (warm environment) or − 17 °C (cold environment). Each heifer received an injection of insulin or growth hormone followed by frequent blood sampling. Plasma samples were analyzed for insulin, insulin-like growth factor I (IGF-1), growth hormone, glucagon, triiodothyronine, thyroxine and glucose. Basal plasma concentrations of all hormones except growth hormone and IGF-1 were elevated (P < 0.05) in the cold environment. Kinetic parameters for growth hormone and insulin were calculated using a two-pool model. Both the zero-time intercept and the rate constant for the slow component of growth hormone were lower (P < 0.05) in cold-adapted animals. The total turnover rate of growth hormone in both pools also tended to be reduced by cold adaptation (P < 0.07). The reduction in growth-hormone turnover may be related to the reduced average daily gains that were observed in the cold (P < 0.05). Plasma glucose concentration following both the insulin and growth-hormone injections was higher in the cold-adapted heifers (P < 0.001 and P < 0.05, respectively). The response of glucagon to insulin injection was greater in the cold (P < 0.05), as was the response of IGF-I to growth-hormone injection (P < 0.10). These cold-induced alterations in the endocrine system appear to be directed toward providing substrates, including glucose, for use in thermogenesis rather than growth. Key words: Cold adaptation, growth hormone, insulin, metabolic clearance rate, hormone kinetics, cattle

Cl- regulates cryoglobulin structure: a new hypothesis for the physiopathological mechanism of temperature non-dependent cryoprecipitation

2004 ◽  
Vol 42 (6) ◽  
Author(s):  
Enrico Di Stasio ◽  
Patrizia Bizzarri ◽  
Milvia Casato ◽  
Antonio Galtieri ◽  
Massimo Fiorilli ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Clinical Signs ◽  
Cold Temperature ◽  
Pathogenetic Mechanism ◽  
Temperature Dependent ◽  
Temperature Changes ◽  
Significant Temperature ◽  
Neoplastic Disorders ◽  
New Hypothesis

AbstractCryoglobulins are pathological cold-precipitable immunoglobulins associated with a number of infectious, autoimmune and neoplastic disorders. Patients, when exposed to low temperatures, show symptoms related to intravascular precipitation of such immunoglobulins. The formation of cryoaggregates induced by exposure to cold temperature is the key pathogenetic mechanism. The subsequent intravascular precipitation can account for some clinical signs of peripheral vasculitis, but fails to explain the precipitation of cryoglobulins in regions where no significant temperature changes take place. We studied, in vitro, the activity of different ions on temperature-dependent aggregation of cryoglobulins and found that the concentration of Cl

scholarly journals Effect of cold temperature on the length of incubation of Chamaeleo chamaeleon

2007 ◽  
Vol 28 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Carmen Díaz-Paniagua
Keyword(s):  
Body Mass ◽  
Low Temperatures ◽  
Cold Temperature ◽  
Cold Period

AbstractCommon chameleon eggs spend the first months of incubation at low temperatures. I incubated eggs of different clutches at 25°C in four treatments with respectively 0, 84, 119 and 149 days of initial cold period (at 14°C). Treatments with longer cold periods had longer total incubation but shorter periods of incubation at 25°C. Eggs which did not experience initial cold period showed low synchronization at hatching. Hatchling body mass and length were influenced by the length of the cold period. Hatchlings were largest and heaviest for cold periods of intermediate length which had similar duration than the cold period experienced by eggs in nature. These results suggest that the cold torpor period of Common chameleon embryos contributes to optimization of development and growth, and synchronizes hatching.

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