Acremonium boreale n.sp., a sclerotial, low-temperature-tolerant, snow mold antagonist

1979 ◽  
Vol 57 (20) ◽  
pp. 2122-2139 ◽  
Author(s):  
J. Drew Smith ◽  
John G. N. Davidson
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Grass Species ◽  
Western Canada ◽  
Eastern Canada ◽  
Snow Mold ◽  
Typhula Ishikariensis ◽  
Wide Range ◽  
Ecological Importance ◽  
Fusarium Nivale

A previously undescribed, sclerotial, low-temperature-tolerant fungus with orange sclerotia, is common on a wide range of plant species and substrates in Western Canada. It is often associated with snow mold complexes. It has also been found in eastern Canada and Norway, indicating a circumpolar distribution. It is described as Acremonium boreale n.sp. Some isolates were antagonistic towards common snow molds, viz. Fusarium nivale, Sclerotica borealis, Typhula ishikariensis var. ishikariensis and var. canadensis, and the nonsclerotial low-temperature basidiomycete in culture at low temperatures. Although it was weakly parasitic towards two grass species, its main ecological importance seems to be as an invasive primary saprophyte on a wide range of substrates. It may play a significant role in determining the nature and intensity of damage in snow mold complexes.

scholarly journals Preliminary tests on winter cereal varieties of resistance to low temperature parasitic fungi in controlled conditions

1968 ◽  
Vol 40 (2) ◽  
pp. 88-95
Author(s):  
H. H. Blomqvist ◽  
E. A. Jamalainen
Keyword(s):  
Low Temperature ◽  
Winter Wheat ◽  
Field Trials ◽  
Winter Rye ◽  
Wheat Varieties ◽  
Winter Cereal ◽  
Typhula Ishikariensis ◽  
Parasitic Fungi ◽  
Fusarium Nivale ◽  
Winter Wheat Varieties

The present work describes a method for the testing of the resistance of winter cereal varieties to Fusarium nivale, Typhula ishikariensis and T. incarnata. The shooting of the plants was carried out in greenhouses and after a period of 3 weeks of coldhardening the plants were infected, covered with cellulose wadding and placed in a temperature of 2°C. Once the varieties with the highest susceptibility were severely infected by the fungi the test was suspended and the plants were given some 2 weeks to recover prior to being analysed. The tested varieties were well known from field trials during a number of years. The results agree in the main with those obtained in the field. The Finnish winter wheat and winter rye varieties showed a greater degree of resistance to the above fungi than the Swedish ones. The injury inflicted by F. nivale on winter rye was more severe than that on the winter wheat varieties. T. ishikariensis and T. incarnata were considerably more pathogenic to wheat than F. nivale, and the tested varieties showed varying degrees of resistance to these fungi. The results likewise point to a correlation existing in the resistance to the three low temperature parasitic fungi.

Jojoba: Temperature Adaptation as Expressed in Growth and Leaf Function

1983 ◽  
Vol 10 (3) ◽  
pp. 299 ◽  
Author(s):  
IF Wardlaw ◽  
JE Begg ◽  
D Bagnall ◽  
RL Dunstone
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Vascular System ◽  
Starch Content ◽  
Dry Weight ◽  
Co2 Exchange ◽  
Temperature Adaptation ◽  
Pulse Labelling ◽  
Wide Range ◽  
Young Leaves

The adaptation of jojoba [Simmondsia chinensis (Link) Schneider] to temperature was studied under controlled conditions. Shoot extension and leaf area development reflected the very low rate of growth of this species, even under favourable conditions, and were stable with an increase in temperature from 20 to 30°C. However growth was markedly reduced at temperatures below 20°C and at 6°C there was no net gain in dry weight over a 42 day period. Root: shoot ratios were near unity and showed a small drop in response to increasing temperature. Leaves adapted to low temperature by an increase in thickness, specific leaf weight and starch content. Chlorophyll formation was retarded in young leaves developing at 15/10°C, but there was no sign of photodestruction of previously formed chlorophyll in mature leaves. Young leaves developing at 30/25°C had a very high chlorophyll a/b ratio of 9.5, but otherwise leaf chlorophyll was apparently normal (2.3-3.4) over a wide range of temperatures. Light saturation of net CO2 exchange (NCE) occurred at about 1000 �E m-2 s-1 for leaves grown over a wide range of temperatures and the maximum NCE of approximately 16 mg CO2 dm-2 h-1 (0.45 mg m-2 s-1) occurred between 19 and 25°C. Pulse labelling with 14CO2 indicated that low temperature (18°C) reduced the rate of transfer of 14C from the primary products of fixation to sucrose. The rate of movement of 14C-labelled photosynthate out of the leaf was negligible at 18°C, and reached only about 3% h-1 at 30°C. In the stems, shortly after 14CO2 uptake by the leaf, 86% of the 14C activity was in sucrose, indicating that this was the preferred form of translocate in the vascular system. However glucose was more abundant in the leaves than sucrose, particularly at low temperatures. Starch accumulated in the leaves at low temperatures, reaching nearly 30% of the dry weight at 18/13°C. Photosynthetic stability rather than active adaptation appears to form the basis of resistance to temperature stress in jojoba. With low rates even under optimal conditions this is essentially one of adaptation for survival rather than adaptation for production.

scholarly journals Low-temperature dynamics in a dye-doped polymer: correspondence between the data obtained by photon echo and single molecule spectroscopy

2018 ◽  
Vol 190 ◽  
pp. 04008
Author(s):  
Kamil Karimullin ◽  
Andrei Naumov
Keyword(s):  
Low Temperature ◽  
Single Molecule ◽  
Vibrational Relaxation ◽  
Low Temperatures ◽  
Photon Echo ◽  
Single Molecule Spectroscopy ◽  
Dye Molecules ◽  
Wide Range ◽  
Temperature Dynamics ◽  
Doped Polymer

Low temperature dynamics (tunneling and vibrational relaxation) in doped polyisobutylene film has been reinvestigated using 2-pulse incoherent photon echo (2IPE) and compared with single-molecule spectroscopy (SMS) data. It has been shown that in a very wide range of low temperatures the 2IPE gives optical dephasing times which correspond to the narrowest zero-phonon lines of single dye molecules.

scholarly journals Microbial Ecology from the Himalayan Cryosphere Perspective

2020 ◽  
Vol 8 (2) ◽  
pp. 257 ◽  
Author(s):  
Kusum Dhakar ◽  
Anita Pandey
Keyword(s):  
Low Temperature ◽  
Microbial Ecology ◽  
Higher Plants ◽  
Biological Activities ◽  
Large Fraction ◽  
Polar Regions ◽  
Cold Environments ◽  
Wide Range ◽  
Extreme Cold ◽  
Ecological Importance

Cold-adapted microorganisms represent a large fraction of biomass on Earth because of the dominance of low-temperature environments. Extreme cold environments are mainly dependent on microbial activities because this climate restricts higher plants and animals. Himalaya is one of the most important cold environments on Earth as it shares climatic similarities with the polar regions. It includes a wide range of ecosystems, from temperate to extreme cold, distributed along the higher altitudes. These regions are characterized as stressful environments because of the heavy exposure to harmful rays, scarcity of nutrition, and freezing conditions. The microorganisms that colonize these regions are recognized as cold-tolerant (psychrotolerants) or/and cold-loving (psychrophiles) microorganisms. These microorganisms possess several structural and functional adaptations in order to perform normal life processes under the stressful low-temperature environments. Their biological activities maintain the nutrient flux in the environment and contribute to the global biogeochemical cycles. Limited culture-dependent and culture-independent studies have revealed their diversity in community structure and functional potential. Apart from the ecological importance, these microorganisms have been recognized as source of cold-active enzymes and novel bioactive compounds of industrial and biotechnological importance. Being an important part of the cryosphere, Himalaya needs to be explored at different dimensions related to the life of the inhabiting extremophiles. The present review discusses the distinct facts associated with microbial ecology from the Himalayan cryosphere perspective.

scholarly journals Testing and Applications of Non-Linear Wave Shaping Circuits Based on Zener Diodes at Cryogenic Temperatures

2017 ◽  
Vol 13 (4) ◽  
pp. 4910-4918
Author(s):  
A. M. Abd El-Maksood
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
The Other ◽  
Electronic Systems ◽  
Linear Wave ◽  
Cryogenic Temperatures ◽  
Temperature Variations ◽  
Wide Range ◽  
Non Linear ◽  
The Stability

            Applications of wave-shaping clipping circuits based on Zener diodes are of great interest in a wide range of modern electronic systems. As well, given the strong interest in space research and trips to distant planets, where the journey takes long periods. Therefore, the matter requires reliance on electronic systems with special specifications commensurate with the nature of the extremely low-temperature environments, down to cryogenic level (around 90 K). So, the present paper was concerned with studying the stability of the performance of different non-linear wave-shaping systems, based on silicon Zener diodes, whenever operates at very low temperatures down to cryogenic levels. From which, it is clear that for BZX79-C4V7 and BZX79-C5V6 Zeners, such electronic systems were shown to be insensitive to temperature variations. On the other hand, low breakdown voltage Zeners (BZV86-1V4 and BZX83-C3V6), the clipping edges were shown to be increased with lowering temperatures from 300 K down to 93 K. Finally, for Zener diodes with VZ greater than 6.0 V (BZX83-C6V8 and BZX55C9V1), the temperature coefficient is positive, so the clipping edges decrease with lowering temperatures, for the same range of temperatures.

VITAMIN REQUIREMENTS OF A LOW-TEMPERATURE BASIDIOMYCETE

1962 ◽  
Vol 40 (10) ◽  
pp. 1347-1354 ◽  
Author(s):  
E. W. B. Ward
Keyword(s):  
Low Temperature ◽  
Optimum Concentration ◽  
Western Canada ◽  
Shake Culture ◽  
Optimum Growth ◽  
Mineral Salts ◽  
Snow Mold ◽  
Absolute Requirement ◽  
Vitamin Requirements

The vitamin requirements of an unidentified basidiomycete, the cause of severe snow mold of grasses and legumes in Western Canada, have been determined in shake culture. In a medium composed of D-glucose, L-asparagine, and mineral salts, a mixture of several vitamins supported optimum growth, but an absolute requirement was demonstrated only for thiamine. Pyridoxine stimulated growth in the presence of thiamine. The optimum concentration of thiamine was 50 μg per liter and below this level growth was proportional to concentration. Pyridoxine was effective in the range 50–100 μg per liter in the presence of 50 μg per liter of thiamine. The requirement for thiamine could be satisfied by a mixture of equivalent amounts of thiazole and pyrimidine but not by either alone.

Production of low temperature active lipase from the pink snow mold, Microdochium nivale (syn. Fusarium nivale)

1996 ◽  
Vol 18 (5) ◽  
pp. 509-510 ◽  
Author(s):  
Tamotsu Hoshino ◽  
Satoru Ohgiya ◽  
Tadayuki Shimanuki ◽  
Kozo Ishizaki
Keyword(s):  
Low Temperature ◽  
Microdochium Nivale ◽  
Snow Mold ◽  
Fusarium Nivale ◽  
Active Lipase

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

INVAR M93

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Low Temperatures ◽  
Bend Strength ◽  
Temperature Performance ◽  
Ni Content ◽  
Precision Alloys ◽  
Ni Alloy

Abstract Invar is an Fe-Ni alloy with 36% Ni content that exhibits the lowest expansion of known metals from very low temperatures up to approximately 230 deg C (445 deg F). Invar M93 is a cryogenic Invar with improved weldability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear and bend strength as well as fracture toughness and fatigue. It also includes information on low temperature performance as well as forming and joining. Filing Code: FE-143. Producer or source: Metalimphy Precision Alloys.

The High-Frequency Decay Slope of Spectra (Kappa) for M≥3.5 Earthquakes on Rock Sites in Eastern and Western Canada

2020 ◽  
Vol 110 (2) ◽  
pp. 471-488 ◽  
Author(s):  
Samantha M. Palmer ◽  
Gail M. Atkinson
Keyword(s):  
Ground Motion ◽  
Classical Method ◽  
Vertical Component ◽  
Western Canada ◽  
S Wave ◽  
Motion Modeling ◽  
Eastern Canada ◽  
General Observation ◽  
Anelastic Attenuation ◽  
Two Parameters

ABSTRACT Spectral decay of ground-motion amplitudes at high frequencies is primarily influenced by two parameters: site-related kappa (κ0) and regional Q (quality factor, inversely proportional to anelastic attenuation). We examine kappa and apparent Q-values (Qa) for M≥3.5 earthquakes recorded at seismograph stations on rock sites in eastern and western Canada. Our database contains 20 earthquakes recorded on nine stations in eastern Canada and 404 earthquakes recorded on eight stations in western Canada, resulting in 105 and 865 Fourier amplitude spectra, respectively. We apply two different methods: (1) a modified version of the classical S-wave acceleration method; and (2) a new stacking method that is consistent with the use of kappa in ground-motion modeling. The results are robust with respect to the method used and also with respect to the frequency band selected, which ranges from 9 to 38 Hz depending on the region, event, and method. Kappa values obtained from the classical method are consistent with those of the stacked method, but the stacked method provides a lower uncertainty. A general observation is that kappa is usually larger, and apparent Q is smaller, for the horizontal component in comparison to the vertical component. We determine an average regional κ0=7  ms (horizontal) and 0 ms (vertical) for rock sites in eastern Canada; we obtain κ0=19  ms (horizontal) and 14 ms (vertical) for rock sites in western Canada. We note that kappa measurements are quite sensitive to details of data selection criteria and methodology, and may be significantly influenced by site effects, resulting in large site-to-site variability.

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