LOW TEMPERATURE AS A FACTOR IN THE MORTALITY OF EGGS OF MANTIS RELIGIOSA L.

1947 ◽  
Vol 79 (2) ◽  
pp. 33-36 ◽  
Author(s):  
R. W. Salt ◽  
H. G. James
Keyword(s):  
Low Temperature ◽  
Egg Mortality ◽  
Mantis Religiosa ◽  
Embryonic Growth ◽  
Winter Temperatures

In the district around Belleville, Ontario, the eggs of Mantis religiosa are deposited during the end of August and throughout September. Some embryonic growth occurs after the eggs are laid and before they enter diapause for the winter. Many of the eggs which have over-wintered, however, fail to continue their development so that the percentage of hatch in the following spring is often greatly reduced. This egg mortality varies from year to year. Records obtainrd between 1940 and 1946 by the dissection and incubation of current oothecae collected at the end of March have indicated mortalities ranging from 15.6 to 86.4 per cent. Such mortality has been generally attributed to low winter temperatures although there was also evidence that eggs could be exposed to a temperature as low as−20°C without injury.

Growth and chemical composition of lotononis (Lotononis bainesii) under simulated winter conditions

1972 ◽  
Vol 12 (57) ◽  
pp. 396
Author(s):  
WW Bryan
Keyword(s):  
Chemical Composition ◽  
Low Temperature ◽  
Cold Stress ◽  
Mineral Composition ◽  
Additional Stress ◽  
Light Conditions ◽  
Winter Conditions ◽  
Winter Temperatures ◽  
Growth Experiments

Lotononis remains green in subtropical winters. To determine the effect of low temperature on growth, experiments were done under controlled temperature and light conditions. With a simulated midwinter day of three hours of frost and 10i hours of light and no other stress imposed, plants made slight but definite growth. It is inferred that winter temperatures do not completely prevent growth. When additional stress of partial defoliation was imposed, the amount of growth was reduced to about 15 per cent of that of undefoliated plants. This suggests that if lotononis is grazed in winter any further growth would be of insignificant practical value. Cold stress had little or no effect on mineral composition of the plants. The composition of nodules is recorded.

Physiological differences between races of Teleogryllus commodus (Walker) (Orthoptera : Gryllidae) related to a proposed genetic approach to control

1966 ◽  
Vol 14 (2) ◽  
pp. 245 ◽  
Author(s):  
TW Hogan
Keyword(s):  
Low Temperature ◽  
Population Control ◽  
Temperate Climate ◽  
Genetic Approach ◽  
Field Release ◽  
Teleogryllus Commodus ◽  
Large Numbers ◽  
Winter Temperatures ◽  
Probability Of Success ◽  
Threshold Of Development

A method of population control for a diapausing race of Teleogryllus commodus, based on the introduction of a non-diapausing population, is postulated. One factor that could influence the degree of probability of success of the method is the susceptibility of eggs of the northern tropical race to winter temperatures when exposed to the temperate climate of the south. Tests were conducted which showed that eggs of the tropical race were more vulnerable to low temperature and had a higher threshold of development. Hybrid eggs appear to be intermediate in their ability to survive low temperature. A comparison of the diapausing characteristics of races from widely separated localities in Australia confirmed the non-diapausing characteristic of northern Queensland races; all others showed the ability to enter diapause but varied in the proportion of eggs in which diapause was averted by exposure to high temperature. A method of rearing crickets, suitable for the production of large numbers for field release, is described.

scholarly journals Freezing Tolerance and Nonstructural Carbohydrate Composition of Carpetgrass (Axonopus affinis Chase)

HortScience ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 187-189 ◽  
Author(s):  
Edward Bush ◽  
Paul Wilson ◽  
Dennis Shepard ◽  
James McCrimmon
Keyword(s):  
Low Temperature ◽  
Environmental Factors ◽  
Baton Rouge ◽  
Dry Weight ◽  
Temperature Tolerance ◽  
Nonstructural Carbohydrates ◽  
Carbohydrate Composition ◽  
Low Temperature Tolerance ◽  
Nonstructural Carbohydrate ◽  
Winter Temperatures

An experiment to determine the nonstructural carbohydrate composition and nodal survival (LT50) of common carpetgrass was conducted between 1993 and 1994 at Baton Rouge, La. Nonstructural carbohydrates in stolons were primarily sucrose [70-130 mg·g-1 dry weight (DW)] and starch (8-33 mg·g-1 DW). Total nonstructural carbohydrate (TNC) composition of stolons ranged between 30 to 165 mg·g-1 DW. Node survival following exposure to 2 °C ranged from 0% in August-sampled grass to 48% in December. The LT50 following acclimation under field conditions was -2 to -4 °C. Environmental factors influenced nonstructural carbohydrate composition, partitioning, and node survival. No relationship between TNC concentration and low-temperature tolerance was found. This research confirms previous reports that low-temperature tolerance of carpetgrass is very poor, and its culture may be limited to geographical areas having moderate winter temperatures.

EFFECT OF LOW TEMPERATURES ON MORTALITY OF GRASSHOPPER EGGS (ORTHOPTERA: ACRIDIDAE)

1988 ◽  
Vol 120 (12) ◽  
pp. 1147-1148 ◽  
Author(s):  
M.K. Mukerji ◽  
M.P. Braun
Keyword(s):  
Low Temperatures ◽  
Quantitative Data ◽  
Canadian Prairies ◽  
Egg Mortality ◽  
Winter Temperatures ◽  
The Relationship

Mortality of grasshopper eggs on the Canadian prairies is brought about by many factors, including winter temperatures. Although several authors (Parker 1930; Pickford 1966, 1976; Riegert 1967) have reported that winter temperatures can affect the mortality of grasshopper eggs, no quantitative data have been presented. This note reports the relationship between low temperatures and grasshopper egg mortality

LOW TEMPERATURE INJURY TO ROOTS OF WHITE ELM

1957 ◽  
Vol 33 (2) ◽  
pp. 156-163 ◽  
Author(s):  
H. H. V. Hord ◽  
H. Van Groenewoud ◽  
C. G. Riley
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Cold Weather ◽  
Ulmus Americana ◽  
Ecological Conditions ◽  
Winter Temperatures ◽  
Introduced Trees ◽  
Climatic Records

White elms (Ulmus americana L.) failed to leaf properly at Saskatoon, Saskatchewan, in the spring of 1950 following unusually cold weather in January. Although precipitation in 1949 and the first six months of 1950 was well above average, the symptoms were characteristic of moisture deficiency. Trees on cultivated ground and trees whose growth rate was below average suffered most. On the basis of symptoms, climatic records, and ecological conditions it is concluded that the above-ground symptoms were a result of the killing of roots by unusually low winter temperatures. The occurrence of this injury provides a good example of difficulties that may be encountered when introduced trees are not completely adapted to the environment.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Low temperature x-ray microanalysis of frozen-hydrated tobacco leaves

1984 ◽  
Vol 42 ◽  
pp. 284-285
Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes
Keyword(s):  
Low Temperature ◽  
Lemna Minor ◽  
Root Tips ◽  
Tobacco Leaves ◽  
X Ray ◽  
Whole Cells ◽  
Carbon Coated ◽  
The Right ◽  
Beam Currents ◽  
The University

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

High-Vacuum Evaporation and a Cryostage to Observe Fractured Yeast

1988 ◽  
Vol 46 ◽  
pp. 256-257
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Eugene L. Vigil
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Standard Specimen ◽  
High Vacuum ◽  
Specimen Holder ◽  
Sputter Coating ◽  
Fresh Frozen ◽  
Gain Access ◽  
Scanning Electron ◽  
Transfer Device

Investigators have long realized the potential advantages of using a low temperature (LT) stage to examine fresh, frozen specimens in a scanning electron microscope (SEM). However, long working distances (W.D.), thick sputter coatings and surface contamination have prevented LTSEM from achieving results comparable to those from TEM freeze etch. To improve results, we recently modified techniques that involve a Hitachi S570 SEM, an Emscope SP2000 Sputter Cryo System and a Denton freeze etch unit. Because investigators have frequently utilized the fractured E face of the plasmalemma of yeast, this tissue was selected as a standard for comparison in the present study.In place of a standard specimen holder, a modified rivet was used to achieve a shorter W.D. (1 to -2 mm) and to gain access to the upper detector. However, the additional height afforded by the rivet, precluded use of the standard shroud on the Emscope specimen transfer device. Consequently, the sample became heavily contaminated (Fig. 1). A removable shroud was devised and used to reduce contamination (Fig. 2), but the specimen lacked clean fractured edges. This result suggested that low vacuum sputter coating was also limiting resolution.

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