Search results for "physiology"
showing 10 items of 8671 documents
The importance of thermal history: costs and benefits of heat exposure in a tropical, rocky shore oyster.
2015
Although thermal performance is widely recognized to be pivotal in determining species' distributions, assessment of this performance is often based on laboratory acclimated individuals, neglecting their proximate thermal history. The thermal history of a species sums the evolutionary history and, importantly, the thermal events recently experienced by individuals, including short-term acclimation to environmental variations. Thermal history is perhaps of greatest importance for species inhabiting thermally challenging environments and therefore assumed to be living close to their thermal limits, such as in the tropics. To test the importance of thermal history the responses of the tropical…
Response to: The metabolic cost of whistling is low but measurable in dolphins
2020
Costs of sound production have been investigated only sparsely in cetaceans, despite recent efforts to understand how increasing anthropogenic noise affects these animals that rely extensively on sound for communication and foraging. Theoretical estimates suggest that metabolic costs of whistling
Lung function assessment in the Pacific walrus (Odobenus rosmarus divergens) while resting on land and submerged in water
2020
In the present study, we examined lung function in healthy resting adult (born in 2003) Pacific walruses (Odobenus rosmarus divergens) by measuring respiratory flow ([Formula: see text]) using a custom-made pneumotachometer. Three female walruses (670-1025 kg) voluntarily participated in spirometry trials while spontaneously breathing on land (sitting and lying down in sternal recumbency) and floating in water. While sitting, two walruses performed active respiratory efforts, and one animal participated in lung compliance measurements. For spontaneous breaths, [Formula: see text] was lower when walruses were lying down (e.g. expiration: 7.1±1.2 l s-1) as compared with in water (9.9±1.4 l s-…
Seed Bank in Annuals: Competition Between Banker and Non-banker Morphs
2002
Seed bank is a plant life history strategy against the unpredictability of the biotic and the abiotic environment. We simulated competition between a seed banking and a non-banking morph of an annual plant. A constant fraction of the banker morph seeds was allocated to the seed bank, where they had a constant mortality and germination rate. All surviving seeds of the non-banker morph germinated in the next generation. The seedlings of both morphs experienced similar density-dependent mortality. Whether one of the morphs wins or the morphs coexist was evaluated from parameter space plots and statistically with logistic regression analysis. All parameters of the model had a significant, nonli…
A new C12 alcohol identified as a sex pheromone and a trail-following pheromone in termites: the diene (Z,Z)-dodeca-3,6-dien-1-ol
2003
0028-1042 (Print) Journal Article; The diunsaturated C12 alcohol (Z,Z)-dodeca-3,6-dien-1-ol (dodecadienol) has been characterized by GC-MS and FTIR as a novel releaser pheromone in termites. This alcohol identified in Ancistrotermes pakistanicus (Termitidae, Macrotermitinae) possesses a double pheromonal function which again illustrates the chemical parsimony of termites compared with other social insects. In workers, dodecadienol elicits trail-following at a very low concentration (activity threshold at 0.1 pg/cm of trail); in male alates it induces trail-following at a low concentration (1-10 pg/cm) and sexual attraction at a higher concentration (about 1 ng). Traces of the monounsaturate…
Stomatal deregulation in Plasmopara viticola-infected grapevine leaves.
2007
International audience; In grapevine, the penetration and sporulation of Plasmopara viticola occur via stomata, suggesting functional relationships between guard cells and the pathogen. This assumption was supported by our first observation that grapevine (Vitis vinifera cv. Marselan) cuttings infected by P. viticola wilted more rapidly than healthy ones when submitted to water starvation. • Here, complementary approaches measuring stomatal conductance and infrared thermographic and microscopic observations were used to investigate stomatal opening/closure in response to infection. • In infected leaves, stomata remained open in darkness and during water stress, leading to increased transpir…
Water relations and carbohydrate partitioning of four greenhouse-grown olive genotypes under long-term drought
2016
The four olive genotypes exhibited different responses to drought involving leaf drop and g s reductions (broad-leaved genotypes, good leaf hydration); or growth reductions (narrow-leaved genotypes, dehydration tolerance). There was minor effect on carbohydrate levels. Olive plants of broad-leaved ‘Minuta’ (MN) and ‘Nocellara del Belice’ (NB) and narrow-leaved ‘Passulunara’ (PA) and ‘Biancolilla Siracusana’ (BS) were studied to evaluate their responses to drought. In a greenhouse, 2-year-old rooted cuttings were irrigated to field capacity (WW) or with 20% of WW evapotranspiration (DS) for over 3 months. Subsequently, all pots were rewatered to field capacity for 20 days. Gravimetric soil w…
Anti-Transpirant effects on vine physiology, berry and wine composition of cv. Aglianico (Vitis vinifera L.) grown in South Italy
2019
In viticulture, global warming requires reconsideration of current production models. At the base of this need there are some emerging phenomena: modification of phenological phases
Is it advantageous for Atlantic salmon to be triploid at lower temperatures?
2020
Marine organisms living at low temperatures tend to have larger genomes and larger cells which suggest that these traits can be beneficial in colder environments. In fish, triploidy (three complete sets of chromosomes) can be induced experimentally following fertilization, which provides a model system to investigate the hypothesis that larger cells and genomes offers a physiological advantage at low temperatures. We tested this hypothesis by measuring metabolic rates and swimming performance of diploid and triploid Atlantic salmon (Salmo salar) post smolts acclimated to 3 or 10.5 °C. At 10.5 °C, triploids had significantly lower maximum metabolic rates which resulted in a lower aerobic sco…
Decoupling of light intensity effects on the growth and development of C3 and C4 weed species through sucrose supplementation
2002
Light availability has a profound effect on plant growth and development. One of the ways to study the effects of light intensity on plant growth and development without the confounding problem of photosynthate availability is sucrose injection/supplementation. A greenhouse experiment was conducted to evaluate the effects of light levels (0% and 75% shade) and sucrose injection (distilled water or 150 g sucrose l(-1)) on three weed species: redroot pigweed (Amaranthus retroflexus L., C4), lambsquarters (Chenopodium album L., C3) and velvetleaf (Abutilon theophrasti Medic., C3). The average total sucrose uptake was 7.6 and 5.9 g per plant for 0% and 75% shading, respectively, representing 47…