Plants have two principal defense mechanisms to decrease fitness losses to herbivory: tolerance, the ability to compensate fitness after damage, and resistance, the ability to avoid damage. Variation in intensity of herbivory among populations should result in variation in plant defense levels if tolerance and resistance are associated with costs. Yet little is known about how levels of toleran...

Ectothermic vertebrates have colonized regions that are seasonally or perpetually cold, and some species, particularly terrestrial hibernators, must cope with temperatures that fall substantially below 0°C. Survival of such excursions depends on either freeze avoidance through supercooling or freeze tolerance. Supercooling, a metastable state in which body fluids remain liquid below the equilib...

This study investigated the influence of nanoclay on the impact damage resistance of glass fiber-epoxy composites under high velocity ice impact loading. Addition of 0.5 wt. % nanoclay into epoxy was shown to improve damage resistance compared to composite plates having no nanoclay platelet. The glass fiber-epoxy composites containing nanoclay brought about substantial improvement in ice impact...

Frost damage to the flowers and early developing fruits is one of the most limiting factors in almond cultivation regions of the world. This study was undertaken to understand almond response to frost damage concerning ion leakage in order to develop a criterion for the selection of frost-resistant cultivars in field experiments. In this work, 60 almond cultivars and genotypes on the basis fros...

In order to avoid laser-induced damage to optical components during amplification of a short laser pulse, the pulse often is first stretched in time to reduce its peak power, amplified, and then recompressed. High peak irradiance is attained when the laser beam is subsequently focused onto a laser fusion target. In a laser system, currently under construction, large diffraction gratings will be...

Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stoma...

We compared physiological characteristics and responses to experimental freezing and thawing in winter and spring samples of the wood frog, Rana sylvatica, indigenous to Interior Alaska, USA. Whereas winter frogs can survive freezing at temperatures at least as low as −16C, the lower limit of tolerance for spring frogs was between −2.5C and −5C. Spring frogs had comparatively low levels of the ...

A review is made of recent publications concerning the mechanisms of damage and acclimation of the photosynthetic apparatus due to high temperature. Under stress the organisms undergo first of all destabilisation followed by normalisation and stability, when limit of tolerance are not exceeded and the adaptive capacity is not overtaxed. The influence of heat stress on PSII and PSI activity, lip...