The polar night has recently received increased attention as a surprisingly active biological season. Yet, microbial ecology is vastly understudied field. To identify the physical and biogeochemical parameters driving activity over dark season, we studied sub-Arctic fjord system in northern Norway from autumn to early spring with detailed monthly sampling. We focused on impact of mixing, terres...

Arctic sea ice is becoming a more seasonal phenomenon as direct result of global warming. Across the Arctic, refreezing ocean surface each autumn now occurs full month later than it did just 40 years ago. In western (Canada Basin), delay related to an increase in heat stored waters; cooling freezing point requires loss atmosphere autumn. marginal zone, and process mediated by mixing presence re...

Under normal field growth conditions, canola (Brassica napus) seeds produce chloroplasts during early seed development and then catabolize the photosynthetic machinery during seed maturation, producing mature seeds at harvest that are essentially free of chlorophyll (Chl). However, frost exposure early in canola seed development disrupts the normal programming of Chl degradation, resulting in g...

Cold-induced mortality has historically been a key aspect of mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), population control, but little is known about the molecular basis for cold tolerance in this insect. We used RNA-seq analysis to monitor gene expression patterns of mountain pine beetle larvae at four time points during their overwintering period-early-...

Since few studies have examined cold tolerance at the organ level in insects, our primary objective was to characterize the functional responses of the gut and Malpighian tubules (MT) to seasonal acclimatization, chilling and freezing in larvae of the goldenrod gall fly Eurosta solidaginis Fitch (Diptera, Tephritidae). From September to December, hemolymph osmolality (455-926 mOsmol kg l(-1)) a...

Pecan [Carya illinoinensis (Wangenh.) C. Koch.] trees were injured by freezing temperatures in Oct. 2000, occurring about 4 weeks before the average first freeze and 6 weeks before the normal killing freeze (less than or equal to –2 °C). Nonbearing and bearing cultivars were rated for injury at four sites the following May. Nonbearing cultivars with little or no damage included ‘Caddo’, ‘Clark ...