abstract r. ficaria is an invasive perennial and tuberous roots weed. the most important means of its reproduction and dispersion are tubers. in order to study the effect of droughty and freezing on germination of lesser celandine tubers, two experiments were conducted at weed science laboratory of faculty of agriculture ferdowsi university of mashhad in 2008. the experiment was a completely ra...

Very little is known about the capacity of soil chytrids to withstand freezing in the field. Tolerance to freezing was tested in 21 chytrids isolated from cropping and undisturbed soils in temperate Australia. Samples of thalli grown on peptone-yeast-glucose (PYG) agar were incubated for seven days at -15 degrees C. Recovery of growth after thawing and transferring to fresh medium at 20 degrees...

Considerable evidence suggests that the lateral (LA) and basal (BA) nuclei of the amygdala are sites of plasticity and storage of emotional memory. Recent arguments, however, have seriously challenged this view, suggesting that the effects of amygdala lesions are attributable to interference with performance of fear behavior and not learning and memory. One way to address this controversy is to...

INTRODUCTION Parkinson's disease patients with freezing of gait also experience sudden motor blocks (freezing) during other repetitive motor tasks. We assessed the proportion of patients with advanced PD and freezing of gait who also displayed segmental "freezing" in tapping tasks. METHODS Fifteen Parkinson's disease patients with freezing of gait were assessed. Freezing of gait was evaluated...

Low temperature induced physiological changes that increased the ability of second-stage juveniles of Meloidogyne hapla to survive external freezing. Second-stage juveniles in polyethylene glycol solution were exposed to -4 , 0, 4, or 24 C, and then their survival was determined after ice-induced freezing of the suspensions at - 4 C for 24 hours. Survival was greatest for juveniles exposed to 4...

[1] Despite its atmospheric importance, homogeneous freezing of aqueous drops is poorly understood. Here we provide evidence that at atmospheric pressures the conditions leading to the initiation of freezing in pure water are those for which the liquid compressibility and the corresponding density fluctuations reach maxima. This liquid-only criterion for the onset of freezing contrasts with the...

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...

Kudoa septempunctata in olive flounder meat was inactivated using 3 distinct freezing methods：liquid freezing for 5 min, air blast freezing at －30℃ for 5 h, and －80℃ for 1 h. The fracture curve of olive flounder meat subjected to liquid freezing resembled that of meat stored at 4℃, indicating that the structure of olive flounder muscle was well preserved. In contrast, air blast freezing induced...

Background: The slow-freezing method is one of the most popular techniques to freeze human oocytes and it is also used in routine in vitro-fertilization (IVF) programs, particularly in those countries where embryo freezing is not allowed. Slow-freezing damages some of the structures of the egg, among which the meiotic spindle (MS) and the zona pellucida (ZP). Polarized Light Microscopy (PLM) pe...

Plants vary greatly in their ability to survive freezing temperatures. At one extreme are plants from tropical regions that have virtually no capacity to survive even the slightest freeze. In contrast, herbaceous plants from temperate regions generally survive freezing temperatures ranging from 25°C to 230°C, depending on the species, whereas perennials in the boreal forests routinely survive w...