Shifting of frozen ground boundary in response to temperature variations at northern China and Mongolia, 2000-2007

2013 ◽  
Vol 33 (7) ◽  
pp. 1844-1848 ◽  
Author(s):  
Lijian Han ◽  
Atsushi Tsunekawa ◽  
Mitsuru Tsubo
Keyword(s):  
Northern China ◽  
Frozen Ground ◽  
Temperature Variations ◽  
Response To Temperature

scholarly journals Significant stream chemistry response to temperature variations in a high-elevation mountain watershed

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Wei Zhi ◽  
Kenneth H. Williams ◽  
Rosemary W. H. Carroll ◽  
Wendy Brown ◽  
Wenming Dong ◽  
...  
Keyword(s):  
Water Chemistry ◽  
High Elevation ◽  
Stream Chemistry ◽  
Earth System ◽  
Mountain Regions ◽  
Temperature Variations ◽  
Mountain Watershed ◽  
Air Temperatures ◽  
Central Rocky Mountains ◽  
Response To Temperature

Abstract High-elevation mountain regions, central to global freshwater supply, are experiencing more rapid warming than low-elevation locations. High-elevation streams are therefore potentially critical indicators for earth system and water chemistry response to warming. Here we present concerted hydroclimatic and biogeochemical data from Coal Creek, Colorado in the central Rocky Mountains at elevations of 2700 to 3700 m, where air temperatures have increased by about 2 °C since 1980. We analyzed water chemistry every other day from 2016 to 2019. Water chemistry data indicate distinct responses of different solutes to inter-annual hydroclimatic variations. Specifically, the concentrations of solutes from rock weathering are stable inter-annually. Solutes that are active in soils, including dissolved organic carbon, vary dramatically, with double to triple peak concentrations occurring during snowmelt and in warm years. We advocate for consistent and persistent monitoring of high elevation streams to record early glimpse of earth surface response to warming.

scholarly journals Sensory determinants of behavioral dynamics in Drosophila thermotaxis

2014 ◽  
Vol 112 (2) ◽  
pp. E220-E229 ◽  
Author(s):  
Mason Klein ◽  
Bruno Afonso ◽  
Ashley J. Vonner ◽  
Luis Hernandez-Nunez ◽  
Matthew Berck ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Temperature Gradients ◽  
Temperature Variations ◽  
Motor Responses ◽  
Voltage Imaging ◽  
Behavioral Dynamics ◽  
Strategic Value ◽  
Preferred Temperatures ◽  
Response To Temperature

Complex animal behaviors are built from dynamical relationships between sensory inputs, neuronal activity, and motor outputs in patterns with strategic value. Connecting these patterns illuminates how nervous systems compute behavior. Here, we study Drosophila larva navigation up temperature gradients toward preferred temperatures (positive thermotaxis). By tracking the movements of animals responding to fixed spatial temperature gradients or random temperature fluctuations, we calculate the sensitivity and dynamics of the conversion of thermosensory inputs into motor responses. We discover three thermosensory neurons in each dorsal organ ganglion (DOG) that are required for positive thermotaxis. Random optogenetic stimulation of the DOG thermosensory neurons evokes behavioral patterns that mimic the response to temperature variations. In vivo calcium and voltage imaging reveals that the DOG thermosensory neurons exhibit activity patterns with sensitivity and dynamics matched to the behavioral response. Temporal processing of temperature variations carried out by the DOG thermosensory neurons emerges in distinct motor responses during thermotaxis.

scholarly journals Temperature Variations and Possible Forcing Mechanisms over the Past 300 Years Recorded at Lake Chaonaqiu in the Western Loess Plateau

2021 ◽  
Vol 13 (20) ◽  
pp. 11376
Author(s):  
Keke Yu ◽  
Le Wang ◽  
Lipeng Liu ◽  
Enguo Sheng ◽  
Xingxing Liu ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
Northern China ◽  
Temperature Reconstruction ◽  
Dominant Factor ◽  
Carbonate Content ◽  
Temperature Variations ◽  
Decadal Scale ◽  
Forcing Mechanisms ◽  
Western Loess Plateau

Understanding the synchronicity of and discrepancy among temperature variations on the western Loess Plateau (WLP), China, is critical for establishing the drivers of regional temperature variability. Here we present an authigenic carbonate-content timeseries spanning the last 300 years from sediments collected from Lake Chaonaqiu in the Liupan Mountains, WLP, as a decadal-scale record of temperature. Our results reveal six periods of relatively low temperature, during the intervals AD 1743–1750, 1770–1780, 1792–1803, 1834–1898, 1930–1946, and 1970–1995, and three periods of relatively high temperature during 1813–1822, 1910–1928, and since 2000. These findings are consistent with tree-ring datasets from the WLP and correlate well with extreme cold and warm events documented in historical literature. Our temperature reconstruction is also potentially representative of large-scale climate patterns over northern China and more broadly over the Northern Hemisphere. The Pacific Decadal Oscillation (PDO) might be the dominant factor affecting temperature variations over the WLP on decadal timescales.

Effect of Temperature on Ectotherm Tissue Ultrastructure

1971 ◽  
Vol 29 ◽  
pp. 240-241
Author(s):  
Robert Giaquinta ◽  
James A. MacMahon
Keyword(s):  
Standard Procedure ◽  
Temperature Acclimation ◽  
Cellular Level ◽  
Effect Of Temperature ◽  
Limited Information ◽  
Compensatory Mechanisms ◽  
Temperature Variations ◽  
Crotalus Cerastes ◽  
The Subject ◽  
Response To Temperature

Environmental temperature variations result in physiological compensations in the metabolism of ectotherms. These compensatory mechanisms are manifested at various organizational levels within the organism. Compensatory changes at the cellular level constitute the most fundamental mechanisms involved during the acclimation process. The metabolism of various tissues during temperature acclimation has been the subject of numerous investigations (Prosser, 1967). Hochachka (1967) demonstrated increased activities of various metabolic pathways including the pentose shunt, lipogenesis and glycogenesis during cold temperature compensation. Limited information is available concerning the ultrastructure correlates of tissues in response to temperature variations and temperature extremes. This paper reports some preliminary results concerning the effect of temperature on the ultrastructure of various tissues of ectotherms.Heart, liver, skeletal muscle, and brain tissue were excised from heat killed sidewinders, Crotalus cerastes, as were tissues from C. cerastes acclimated to 20 and 30 C. Prefixation was carried out in 3%, cacodylate buffered glutaraldehyde followed by postfixation in 1%, osmium tetroxide. Acetone dehydration and epon embedment were according to standard procedure.

scholarly journals Spatial variations in snow cover and seasonally frozen ground over northern China and Mongolia, 1988–2010

2014 ◽  
Vol 116 ◽  
pp. 139-148 ◽  
Author(s):  
Lijian Han ◽  
Atsushi Tsunekawa ◽  
Mitsuru Tsubo ◽  
Chunyang He ◽  
Miaogen Shen
Keyword(s):  
Snow Cover ◽  
Northern China ◽  
Spatial Variations ◽  
Frozen Ground

scholarly journals Chemical composition and thermal behavior of five brands of thermoplasticized gutta-percha

2013 ◽  
Vol 07 (02) ◽  
pp. 201-206 ◽  
Author(s):  
Claudio Maniglia-Ferreira ◽  
Eduardo Diogo Gurgel-Filho ◽  
João Batista de Araújo Silva-Jr ◽  
Regina Célia Monteiro de Paula ◽  
Judith Pessoa de Andrade Feitosa ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Thermal Behavior ◽  
Chemical Elements ◽  
Beta Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Temperature Variations ◽  
X Ray ◽  
Gutta Percha ◽  
Response To Temperature

ABSTRACT Objective: The aim of this study was determine the chemical composition and thermal behavior of Thermafil (TH), Microseal Cone (MC), Microseal Microflow (MF), Obtura (OB) and Obtura Flow (OF). In addition, their thermal behavior in response to temperature variations was studied by differential scanning calorimetry (DSC) to determine the temperature at which gutta-percha switches from the beta to alpha form, and from the alpha to the amorphous phase. Materials and Methods: The organic and inorganic fractions were separated by dissolution in chloroform. Gutta-percha (GP) was precipitated with acetone. The inorganic fraction was analyzed via Elemental Microanalysis. Energy Dispersive X-ray Microanalysis and X-ray Diffraction were used to identify the chemical elements and compounds (BaSO4 and ZnO). Thermal analysis was conducted using DSC. Results: The organic and inorganic fractions ranged from 21.3% and 26.9% of weights, respectively. MC and MF showed the highest percentages of organic compounds (P = 0.0125). All specimens exhibited two crystalline transformations when heated from ambient temperature to 130°C. MC presented the highest percentage of GP. Conclusions: No correlation was observed between chemical composition and thermal behavior. Each of the products showed thermal behavior that is typical of beta-phase gutta-percha.

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