scholarly journals Cold-hardening during long-term acclimation in a freeze-tolerant woolly bear caterpillar,Pyrrharctia isabella

2015 ◽  
Vol 219 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Shu-Xia Yi ◽  
Richard E. Lee
Keyword(s):  
Cold Hardening ◽  
Pyrrharctia Isabella ◽  
Freeze Tolerant

scholarly journals Constraints, independence, and evolution of thermal plasticity: Probing genetic architecture of long- and short-term thermal acclimation

2015 ◽  
Vol 112 (14) ◽  
pp. 4399-4404 ◽  
Author(s):  
Alison R. Gerken ◽  
Olivia C. Eller ◽  
Daniel A. Hahn ◽  
Theodore J. Morgan
Keyword(s):  
Cold Tolerance ◽  
Negative Correlation ◽  
Genetic Architecture ◽  
Cold Hardening ◽  
Short Term ◽  
Heritable Variation ◽  
Thermal Plasticity ◽  
Rapid Cold Hardening ◽  
Basal Thermotolerance

Seasonal and daily thermal variation can limit species distributions because of physiological tolerances. Low temperatures are particularly challenging for ectotherms, which use both basal thermotolerance and acclimation, an adaptive plastic response, to mitigate thermal stress. Both basal thermotolerance and acclimation are thought to be important for local adaptation and persistence in the face of climate change. However, the evolutionary independence of basal and plastic tolerances remains unclear. Acclimation can occur over longer (seasonal) or shorter (hours to days) time scales, and the degree of mechanistic overlap is unresolved. Using a midlatitude population ofDrosophila melanogaster, we show substantial heritable variation in both short- and long-term acclimation. Rapid cold hardening (short-term plasticity) and developmental acclimation (long-term plasticity) are positively correlated, suggesting shared mechanisms. However, there are independent components of these traits, because developmentally acclimated flies respond positively to short-term acclimation. A strong negative correlation between basal cold tolerance and developmental acclimation suggests that basal cold tolerance may constrain developmental acclimation, whereas a weaker negative correlation between basal cold tolerance and short-term acclimation suggests less constraint. Using genome-wide association mapping, we show the genetic architecture of rapid cold hardening and developmental acclimation responses are nonoverlapping at the SNP and corresponding gene level. However, genes associated with each trait share functional similarities, including genes involved in apoptosis and autophagy, cytoskeletal and membrane structural components, and ion binding and transport. These results indicate substantial opportunity for short-term and long-term acclimation responses to evolve separately from each other and for short-term acclimation to evolve separately from basal thermotolerance.

Allometry of cooling, supercooling, and freezing in the freeze-tolerant turtle Chrysemys picta

1991 ◽  
Vol 261 (3) ◽  
pp. R626-R632 ◽  
Author(s):  
D. L. Claussen ◽  
P. A. Zani
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Bound Water ◽  
Chrysemys Picta ◽  
Ice Formation ◽  
Term Survival ◽  
Freeze Tolerant ◽  
The Relationship ◽  
Kinetics Of

Although several vertebrates are freeze tolerant, little is known of the relationship between body size and the kinetics of cooling and freezing. We compared these responses for six hatchling and eight adult Chrysemys picta from an Ohio population. All turtles initially recovered from freezing, and all adults, but only two hatchlings (which experienced ice contents of approximately 35%), exhibited long-term survival. Rapid thawing may have compromised hatchling survival. Turtle water content was inversely related to body mass, but we found no significant correlation between the extent of supercooling and body size. Prefreezing and postfreezing cooling rates scaled with body mass to the -0.55 and -0.40 power, respectively, but the latter rate was more than two orders of magnitude slower. Theoretical (assuming 20% bound water) and calorimetric estimates of body ice agreed reasonably well. Ice contents were both body mass and time dependent. The absolute rate of ice formation scaled with body mass to the 0.4 power. Body size strongly influences the freezing response of ectotherms and deserves more attention.

scholarly journals Cold hardening protects cereals from oxidative stress and necrotrophic fungal pathogenesis

2016 ◽  
Vol 11 (1) ◽  
pp. 78-85 ◽  
Author(s):  
Miklós Pogány ◽  
Borbála Harrach ◽  
Zoltán Bozsó ◽  
András Künstler ◽  
Tibor Janda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cold Hardening ◽  
Pyrenophora Teres ◽  
Cross Tolerance ◽  
Partial Protection ◽  
Barley Cultivars ◽  
Fungal Phytopathogen ◽  
Signaling Components ◽  
Necrotic Symptoms

AbstractThe effects of cold hardening of cereals on their cross-tolerance to treatments leading to oxidative stress were investigated. Long-term exposure to low non-freezing temperatures provided partial protection to wheat and barley plants from the damage caused by paraquat and hydrogen peroxide treatments. It also conferred resistance in two barley cultivars to the necrotic symptoms and growth of the fungal phytopathogen Pyrenophora teres f. teres. Pathogen-induced oxidative burst was also reduced in cold hardened plants. The possible roles of host-derived redox factors and other signaling components in the observed forms of cereal cross-tolerance are discussed.

scholarly journals A mixture of innate cryoprotectants is key for cryopreservation of a drosophilid fly larva.

2021 ◽  
Author(s):  
Lukas Kucera ◽  
Martin Moos ◽  
Tomas Stetina ◽  
Jaroslava Korbelova ◽  
Petr Vodrazka ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
High Resolution Mass Spectrometry ◽  
Viscoelastic Liquid ◽  
Environmental Stressors ◽  
Amorphous Glass ◽  
Freeze Tolerant ◽  
The Individual ◽  
Viscoelastic Liquids ◽  
Ice Fraction

Background: Organisms evolved biochemical strategies to cope with environmental stressors. For instance, insects that naturally tolerate internal freezing produce complex mixtures of multiple cryoprotectants (CPs). Better knowledge on composition of these mixtures, and on mechanisms of how the individual CPs interact, could inspire development of laboratory CP formulations optimized for cryopreservation of cells and other biological material. Results: Here we identify and quantify (using high resolution mass spectrometry) a range of putative CPs in larval tissues of a subarctic fly, Chymomyza costata, that survives long-term cryopreservation in liquid nitrogen. The CPs (proline, trehalose, glutamine, asparagine, glycine betaine, glycerophosphoethanolamine, glycerophosphocholine, and sarcosine) accumulate in hemolymph in a ratio of 313:108:55:26:6:4:3:0.5 mmol.L-1. Using calorimetry, we show that the artificial mixtures, mimicking the concentrations of major CPs' in hemolymph of freeze-tolerant larvae, suppress the melting point of water and significantly reduce the ice fraction. We demonstrate in a bioassay that mixtures of CPs administered through the diet act synergistically rather than additively to enable cryopreservation of otherwise freeze-sensitive larvae. Using MALDI-MSI, we show that during slow extracellular freezing of whole larvae trehalose becomes concentrated in partially dehydrated hemolymph and stimulates transition to the amorphous glass phase. In contrast, proline moves to the boundary between extracellular ice and dehydrated hemolymph and tissues where it likely forms a layer of dense viscoelastic liquid. Conclusion: Our results suggest that different components of innate cryoprotective mixtures of freeze-tolerant insect act in synergy during extracellular freezing. We propose that transitions to amorphous glass (stimulated by trehalose) and viscoelastic liquids (having proline as major component) may protect macromolecules and cells from thermomechanical shocks associated with freezing and transfer into and out of liquid nitrogen.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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