Closure to “Discussion of ‘Factors Affecting the Transformation to Gray Tin at Low Temperatures’ [R. R. Rogers and J. F. Fydell (pp. 383–387)]”

1954 ◽  
Vol 101 (6) ◽  
pp. 335
Author(s):  
R. R. Rogers ◽  
J. F. Fydell
Keyword(s):  
Low Temperatures ◽  
Factors Affecting

Factors affecting seed set in Douglas-fir (Pseudotsuga menziesii)

1991 ◽  
Vol 69 (2) ◽  
pp. 229-238 ◽  
Author(s):  
John N. Owens ◽  
Anna M. Colangeli ◽  
Sheila J. Morris
Keyword(s):  
Reproductive Success ◽  
Pseudotsuga Menziesii ◽  
Low Temperatures ◽  
Seed Set ◽  
Douglas Fir ◽  
Ovule Development ◽  
High Moisture ◽  
Embryo Abortion ◽  
Factors Affecting ◽  
Major Loss

Cone and seed development in Douglas-fir were studied from pollination until seed release in 1986. Cone abortion at, and shortly after, pollination was high, resulting from a combination of low temperatures and possibly high moisture and populations of microorganisms on cones. Seed potential averaged about 75 seeds per cone with 31 filled seed per cone, giving an average seed efficiency of 39%. The major loss of seed resulted from insufficient pollen in the ovules. Other causes were ovule and embryo abortion at various stages of development. The effects of prezygotic and postzygotic events on seed set are discussed with respect to the reproductive success of Douglas-fir. Key words: Douglas-fir, seed set, cone, ovule, development, abortion.

ENVIRONMENTAL AND PHYSIOLOGICAL FACTORS REGULATE FLOWERING

1998 ◽  
Vol 46 (1) ◽  
pp. 47-51
Author(s):  
Osnat Ohana ◽  
David Weiss
Keyword(s):  
Genetic Variation ◽  
High Temperature ◽  
Flowering Time ◽  
Low Temperatures ◽  
Apical Meristem ◽  
Flowering Plants ◽  
Cut Flower ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Bud Size

Eryngium planum was introduced as a cut flower in Israel 20 years ago. So far, all efforts to hasten and synchronize flowering time have failed. In the present work we study the factors affecting eryngium flowering. We found that variation in flowering time is not caused by genetic variation but probably by physiological factors. Exposure of root cuttings to low temperature (2 °C for 2 months) enhanced the percentage of flowering plants but did not shorten time to flowering. High temperature during growth inhibited flowering in vernalized plants, probably via devernalization. Gibberellic acid (GA3) had little, if any, effect on either flowering time or quantity. The size of the initiated bud on the root cuttings was related to flowering time and quantity. Plants from vernalized roots with large buds bloomed faster and at a higher percentage than those from roots with smaller buds. It is suggested that the ability to respond to inductive low temperatures is related to the size of the apical meristem, which is correlated to bud size.

Cold-induced lipid phase transitions

1990 ◽  
Vol 326 (1237) ◽  
pp. 555-570 ◽  
Keyword(s):  
Low Temperatures ◽  
Membrane Lipids ◽  
Weak Interactions ◽  
Protective Action ◽  
Biological Membranes ◽  
Membrane Lipid ◽  
Phase Behaviour ◽  
Lipid Phase ◽  
Aqueous Environment ◽  
Factors Affecting

The structural organization of biological membranes is largely determined by the weak interactions existing between their components and between these components and their aqueous environment. These interactions are particularly sensitive to changes in temperature and hydration. The factors influencing membrane lipid phase behaviour are briefly reviewed and used to develop a phase-separation model describing the response of biological membranes to stress. The factors affecting the interaction of cryoprotectants with membrane lipids are explored and their role in the stabilization of membrane organization at low temperatures discussed. It is suggested that the basis of their protective action lies in an ability to preserve the balance of interactions between membrane components at low temperatures at a level similar to that existing under physiological conditions.

Factors Affecting the Spectral Response in a TG/FT-IR Experiment

1994 ◽  
Vol 48 (12) ◽  
pp. 1468-1471 ◽  
Author(s):  
A. Marini ◽  
V. Berbenni ◽  
D. Capsoni ◽  
R. Riccardi ◽  
T. Zerlia
Keyword(s):  
Fourier Transform ◽  
Low Temperatures ◽  
Spectral Response ◽  
Fourier Transform Infrared ◽  
Operational Mode ◽  
Factors Affecting ◽  
Carrier Gas ◽  
Ft Ir

We discuss situations where thermogravimetric/Fourier transform infrared (TG/FT-IR) plots are obtained which differ substantially from the expected ones. The most common of these situations involves samples that release atmospheric components (H2O, CO2) at low temperatures. It is shown that the phenomena are mainly related to the purging action of the carrier gas, which strongly influences the spectroscopic portion of the TG/FT-IR plot. Such an influence, as well as the different situations originating from it, is discussed and explained on the basis of an analogy with the operational mode of a conventional dispersive spectrometer.

scholarly journals Insulating Materials at Very Low Temperatures: A Short Review

2020 ◽  
Vol 10 (3) ◽  
pp. 5590-5595 ◽  
Author(s):  
P. Malelis ◽  
M. Danikas
Keyword(s):  
Electrode Surface ◽  
Low Temperatures ◽  
Short Review ◽  
Partial Discharges ◽  
Future Research ◽  
Insulating Materials ◽  
Factors Affecting

In this paper, a short review is given on insulating materials at very low temperatures. Various insulating materials are investigated in terms of phenomena such as partial discharges. Some of the factors affecting the behavior of the insulating materials at very low temperatures, such as the quality of electrode surface, the stressed insulation volume and the existing bubbles, are also reported and commented upon. Proposals for future research are also discussed.

Some Factors Affecting the Distribution of Euploea Core Corinna (W.s. Macleay) (Lepidoptera: Danainae).

1985 ◽  
Vol 33 (3) ◽  
pp. 339 ◽  
Author(s):  
E Scheermeyer
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Host Plants ◽  
Nerium Oleander ◽  
Factors Affecting ◽  
Breeding Activity ◽  
Temperature Requirements ◽  
Local Breeding

The temperature requirements and availability of host-plants of Euploea core corinna [E. core] (a polyphagous species that attacks Nerium oleander, Hoya sp. and Stephanotis sp. grown as ornamentals in suburban gardens) were studied in Australia. Low temperatures could restrict the distribution of the danaine in southern Australia, and high temperatures exclude it from much of inland Australia. Non-availability of host-plants could also restrict distribution in some places; some introduced host-plants may serve to enlarge the distribution and local breeding activity of E. core.

FACTORS AFFECTING SURVIVAL OF LYOPHILIZED FUNGAL SPORES AND CELLS

1957 ◽  
Vol 3 (3) ◽  
pp. 477-485 ◽  
Author(s):  
R. H. Haskins
Keyword(s):  
Low Temperatures ◽  
Fungal Spores ◽  
Puccinia Graminis ◽  
Percentage Germination ◽  
Vegetative Cells ◽  
Factors Affecting ◽  
Melampsora Lini ◽  
Percentage Survival ◽  
Initial Freezing ◽  
Preliminary Degassing

Spores of Alternaria, Aspergillus, Fusarium, Gliocladium, Penicillium, and Pestalotia, budding vegetative cells of Ustilago, and uredospores of Puccinia graminis, P. helianthi, and Melampsora lini were lyophilized using several techniques and various conditions. The best percentage survival of the lyophilized spores and cells was obtained when the initial freezing of the spore suspensions was just low enough to keep the suspension solid until evaporative freezing conditions were reached. Freezing to very low temperatures was unnecessary. Conditions permitting fast warming of the frozen suspension resulted in increased survival. A preliminary degassing treatment greatly enhanced percentage germination, as did the conditioning of the spores in a moist atmosphere immediately after the opening of the tubes for revival of the organisms.

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