The purpose of the study was to assess photosynthetic thermal acclimation in two ... The lamps produced no visible radiation, and constantly and evenly warmed ...

Jun 16, 2011 ... Exposure to solid layers of calcium, magnesium, or zinc borate ... At 21-32�C, the acclimation period did not affect the distance tunneled. ...

Adaptive variation tends to emerge clinally along environmental gradients or discretely among habitats with limited connectivity. However, in Atlantic killifish (Fundulus heteroclitus), a population genetic discontinuity appears in the absence of obvious barriers to gene flow along parallel salinity clines and coincides with a physiologically stressful salinity. We show that ...

... could either change smoothly and in a clinal fashion or be spatially organized in a more unpredictable ... Ischnura elegans. Body size increased in a clinal fashion along this gradient: animals were small...

... CVIORB]2.0.CO;2 Clinal Variation in Ohio River Basin Populations of the Redfin Shiner (Lythrurus umbratilis) ... of geographic v...

... Energetics of wetsuit diving n Korean women ... 46. Leblanc, J. Factors affecting cold acclimation and thermogenesis in man. Med. Sci. Sports Exer. ...

The toxicity of a compound affects the acclimation and degradation of the compound. The longer the acclimation time, the better the degradation. Compounds with chloro, amino and carbonyl groups have an adverse effect on acclimation and degradation. The position of the functional group has a significant effect on ...

Rates of hybridization vary among angiosperm taxa. Among-taxon variation in hybridization rate has been used to compare the importance of pre- and post-zygotic reproductive isolating mechanisms. Variation in rates of hybridization within a single-species pair would suggest that local conditions also affect reproductive isolation within a single taxonomic context. In this ...

Freezing in winter cereals is a complex phenomenon that can affect various plant tissues differently. To better understand how freezing affects specific tissue in the over wintering organ (crown) of winter cereal crops, non acclimated oats were frozen to -3°C over an extended period and tissue dama...

The reproductive behaviour of the sexually coercive male eastern mosquitofish (Gambusia holbrooki) offers an excellent model system for testing the benefits of reversible thermal acclimation responses to mating success. We acclimated male mosquitofish to either 18 or 30 degrees C (14 h light:10 h dark) for six weeks and tested their ability to obtain ...

Phototoxicity of several environmental contaminants by UV light has been reported in many studies. Nevertheless, field observations suggest the presence of certain defense mechanisms that would protect aquatic organisms against phototoxic damages. The current study was conducted to understand the responses of aquatic receptors to phototoxic chemicals in a natural environment where low dose UV ...

The liver mitochondrial and microsomal membranes of green sunfish and rat were examined by steady state polarisation and differential polarised phase fluorimetry to determine the effects of seasonal adaptation of membrane dynamic structure to temperature. Steady state polarisation studies indicated that the liver mitochondria of green sunfish acclimated to different ...

It is widely appreciated that physiological tolerances differ between life stages. However, few studies have examined stage-related differences in acclimation and hardening. In addition, the behavioural responses involved in determining the form and extent of the short-term phenotypic response are rarely considered. Here, we investigate life stage differences in the ...

A study was conducted to determine the role of concentration of the test chemical, of a second organic compound, and of mutation in the acclimation period before the mineralization of organic compounds in sewage. The acclimation period for the mineralization in sewage of 2 micrograms of 4-nitrophenol (PNP) per liter increased from 6 to 12 days in the ...

A study was conducted to determine the role of concentration of the test chemical, or a second organic compound, and of mutation in the acclimation period before the mineralization of organic compounds in sewage. The acclimation period for the mineralization in sewage of 2 micrograms of 4-nitrophenol (PNP) per liter increased from 6 to 12 days in the ...

A study was conducted to determine the role of concentration of the test chemical, of a second organic compound, and of mutation in the acclimation period before the mineralization of organic compounds in sewage. The acclimation period for the mineralization in sewage of 2 {mu}g of 4-nitrophenol (PNP) per liter increased from 6 to 12 days in the presence ...

Senegalese sole (Solea senegalensis) is a eurytherm teleost that under natural conditions can be exposed to annual water temperature fluctuations between 12 and 26�C. This study assessed the effects of temperature on sole metabolic status, in particular in what concerns plasma free amino acid changes during thermal acclimation. Senegalese sole maintained at 18�C were ...

The ability of marine phytoplankton to acclimate to ultraviolet radiation (UVR) was examined. Monocultures of a subtropical diatom, Chaetoceros gracilis, were maintained under photosynthetically available radiation (PAR-only) and PAR plus UVR (PAR + UVR) for a 48 h exposure period. By 24 h, and for the remainder of the 48 h exposure period, growth rate, pigment concentrations, ...

The effects of acclimation temperature on insect thermal performance curves are generally poorly understood but significant for understanding responses to future climate variation and the evolution of these reaction norms. Here, in Acheta domesticus, we examine the physiological effects of 7-9 days acclimation to temperatures 4 degrees C above and below ...

expression of the cold-regulated Arabidopsis thaliana COR15a gene affects both chloroplast and protoplast freezing tolerance (cold acclimation COR genes cryoprotective proteins) NANCY N. ARTUS*, MATSUO UEMURA acclimation in plants is associated with the expression of COR (cold-regulated) genes that encode polypeptides

. Assimilation responses to internal CO2 concentrations (A/Ci curves) and photosynthetically active radiation (A (A/Ci curves) and photosynthetically active radiation (A/PAR curves) for each species. Acclimation strongly affected by Ca increases. These data emphasize the need to consider plant responses in natural

Red osier dogwood (Cornus stolonifera Michx.) was artificially acclimated by exposing plants to 8-hour short days (SD) and low (15/5 C) temperatures for 54 to 63 days. Several factors including transpiration rate, stomatal resistance, and root conductivity were correlated so that the rate of water loss in acclimating plants was higher during the first 30 ...

The green sturgeon is a long-lived, highly migratory species with populations that are currently listed as threatened. Their anadromous life history requires that they make osmo- and ionoregulatory adjustments in order to maintain a consistent internal milieu as they move between fresh-, brackish-, and seawater. We acclimated juvenile green sturgeon (121 +/- 10.0 g) to 0 ...

Saltwater crocodiles, Crocodylus porosus, possess lingual salt glands which function to remove excess Na(+) and Cl(-) accumulated as a consequence of living in salt water. Little is known about the nature of ion transport systems in C. porosus salt glands and how these systems respond to an osmotic challenge. In the present study, we examined the distribution and regulation of the ...

BackgroundPhotosystem II (PSII) is the most thermally sensitive component of photosynthesis. Thermal acclimation of this complex activity is likely to be critically important to the ability of photosynthetic organisms to tolerate temperature changes in the environment.Methodology/FindingsWe have analysed gene expression using whole-genome microarrays and monitored alterations ...

A knowledge of the natural history of two species of marine Cottidae was used to construct a set of complex a priori hypotheses to test the idea that seasonal temperature acclimation conferred a fitness advantage and to examine whether acclimation responses were constant through development. The species studied were the short-horn sculpin (Myoxocephalus ...

BackgroundPreviously, we have shown there is clinal variation for egg-to-adult developmental time along geographic gradients in Drosophila melanogaster. Further, we also have identified mutations in genes involved in metabolic and neurogenic pathways that affect development time (heterochronic genes). However, we do not know whether these loci ...

... was increased by intravenous injection (200 μl) of hypertonic NaCl (�) or sucrose (). The dosage is presented as ... the eel are not known yet. Administration of hypertonic solution into eels increases pl...

Isoprene emission from plants accounts for nearly half of all non-methane hydrocarbons entering the atmosphere. Light and temperature regulate the instantaneous rate of isoprene emission, but there is increasing evidence that they also affect the capacity for isoprene emission (i...

. Flower bud differentiation in Salix pentandra as affected by photoperiod, temperature and growth (Salix) and poplar are members of the Salicaceae, and a study of adult willow cuttings in controlled

The past twenty years has seen an explosion of research in trying to identify genes involved in cold acclimation. Hundreds of genes are affected by exposure to low temperature but studies have mainly focused on genes that provide cryoprotection or tolerance to dehydrative stress. Some of the genes...

A propagation program for pallid sturgeon Scaphirhynchus albus in the upper Missouri River was implemented by the U. S. Fish and Wildlife Service in 1997. Preliminary research indicated that many hatchery-reared pallid sturgeon were experiencing significant downstream poststocking dispersal, negatively affecting their recruitment. Therefore, the objective of this study was to ...

Temperature strongly affects oxygen solubility in water, oxygen convection in the blood and locomotor activity of the fish. Since oxygen supply and demand are temperature dependent, it was hypothesized that the purinergic control of the heart, one of the most important mediators in oxygen-limited conditions, might also show temperature dependence. Therefore, the present study ...

The degree to which temperature acclimation modifies the acute synthesis of the entire heat-shock protein (Hsp) complement is still unknown, but it may constitute an important mechanism for understanding the differences in acclimation ability among closely related ectothermic species that occupy widely varying thermal environments. In general, eurythermal ...

Dehydrins are proteins associated with conditions affecting the water status of plant cells, such as drought, salinity, freezing and seed maturation. Although the function of dehydrins remains unknown, it is hypothesized that they stabilize membranes and macromolecules during cellular dehydration. Red-osier dogwood (Cornus sericea L.), an extremely freeze-tolerant woody plant, ...

Stem and electrode electric impedance at 14 frequencies were monitored during cold acclimation of alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.). Cold acclimation significantly increased high frequency (e.g. 1.11 megahertz) resistance and reactance but not low frequency (49 hertz) resistance and reactance of both species. High ...

Evolutionary theory holds that geographic isolation of populations with its resultant reproductive isolation is an important factor in the origin of new species. Climatic change alters species' biogeography by creating and eliminating barriers that affect gene flow between populations. For benthic organisms such as shallow marine ostracodes, thermal gradients at ...

Background and AimsCold acclimation modifies the balance of the energy absorbed and metabolized in the dark processes of photosynthesis, which may affect the expression of cold-regulated (COR) genes. At the same time, a gradual acclimation to the relatively high light conditions is observed, thereby minimizing the potential for ...

The acanthocephalan parasite Polymorphus minutus induces both physiological and behavioural effects in its intermediate host, Gammarus pulex. The net effect of parasite infection is to increase the likelihood of transmission to the definitive host. Osmoregulation is an energetically expensive mechanism that allows G. pulex to survive in dilute media. Any factor influencing osmoregulation is thus ...

Groups of female rats (n=20) exposed from 0 to 13 days to Ta's from 8.0� to 29.0�C were given 2.5 mg/kg reserpine i.p.; Tre and gastric ulcers (GU) were recorded 24 h afterwards. At exposure temperatures below 21.0�C there was a highly significant positive correlation between Ta and Tre (r=0.85) and a negative correlation between Ta and GU (r=?0.92). The GU rate after reserpine was not ...

Osmotin is a pathogenesis-related protein exhibiting cryoprotective functions. Our aim was to understand whether it is involved in the cold acclimation of the olive tree (Olea europaea L.), a frost-sensitive species lacking dormancy. We exposed olive trees expressing tobacco osmotin gene under the 35S promoter (35S:osm) [in the same manner as wild type (wt) plants] to cold ...

The capacities of eurythermal ectotherms to withstand wide ranges of temperature are based, in part, on abilities to modulate gene expression as body temperature changes, notably genes encoding proteins of the cellular stress response. Here, using a complementary DNA microarray, we investigated the sequence in which cellular stress response-linked genes are expressed during acute heat stress, to ...

(1) The activity of the endogenously active salivary burster neurones (SBs) shows temperature acclimation and has characteristic cold and warm blockade temperatures. (2) Temperature acclimation affects the upper and lower limits of the temperature range over which SBs are active. The absolute range, in centigrade degrees, during ...

Recent syntheses indicate that global warming affects diverse biological processes, but also highlight the potential for some species to adapt behaviourally or evolutionarily to rapid climate change. Far less attention has addressed the alternative, that organisms lacking this ability may face extinction, a fate projected to befall one-quarter of global biodiversity. This ...

Most experimental procedures on molluscs are done after acclimatization of wild animals to lab conditions. Similarly, short-term acclimation is often unavoidable in a field survey when biological analysis cannot be done within the day of sample collection. However, acclimatization can affect the general physiological condition and particularly the immune ...