Globally, C4 plants dominate hot, open environments, but this general pattern is underpinned by important differences in the biogeography of C4 lineages. In particular, the species richness of C4 Poaceae (grasses) increases strongly with increasing temperature, whereas that of the major C4 eudicot group Chenopodiaceae correlates positively with aridity. Freezing tolerance is a crucial determina...

The vome of isolated protoplasts of rye (Secale cereale L. cv Puma) in a suspending solution at constant concentration is shown to be neglgbly changed by tensions in the plasma membrane which approach that tension necessary to lyse them. This aflows a detailed investigation of the plasma membrane stress-strain relation by micropipette aspiration. Over periods less than a second, the membrane be...

Cells can endure storage at low temperatures such as--196 degrees C for centuries. The challenge is to determine how they can survive both the cooling to such temperatures and the subsequent return to physiological conditions. A major factor is whether they freeze intracellularly. They do so if cooling is too rapid, because with rapid cooling insufficient cell water is removed osmotically to el...

A shift in chaparral species composition occurs from coastal to inland sites of the Santa Monica Mountains of southern California. Past studies have attributed this pattern to differential adaptations of chaparral species to gradients in moisture and solar radiation. We examined an alternate hypothesis, that shifts in species composition from coastal to inland sites is a result of differential ...

Time-temperature profiles of freezing leaves from frost-resistant (Solanum acaule Bitt.) and frost-susceptible (Solanum tuberosum L. subsp. tuberosum Hawkes) types of potatoes did not reveal any major differences. The pattern of change in resistance of leaves to low voltage, low frequency current during freezing was different in the frost-resistant and susceptible leaves. In tissue sections fro...

Corresponding author: Yong Wook Kim Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Korea Tel: +82-2-2228-3716, Fax: +82-2-363-2795, E-mail: [email protected] Copyright © 2011 by Korean Academy of Rehabilitation Medicine J Korean Acad Rehab Med 2011; 35: 153-157 Case Report Freezing of Gait Following ...

Nuclear etic resoaace (NMR) relaxation times were studied in acclhnated and nonacclmated Kharkov winter wheat (Tritlum sestlvwm L.) crowns and acclimated cel aggregates to determine if membrane permeability was altered by freezing. The NMR water signal decay consisted of two exponental c ets: a short one arising from extracellular water, and a long one arising from intracelular water. A slow fr...

The scarcity of C4 plants in cool climates is usually attributed to their lower photosynthetic efficiency than C3 species at low temperatures. However, a lower freezing resistance may also decrease the competitive advantage of C4 plants by reducing canopy duration, especially in continental steppe grasslands, where a short, hot growing season is bracketed by frost events. This paper reports an ...