Armelle Ansart

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Helix aspersa hibernates in Brittany (western France), where it may experience subzero temperatures. Studies on cold hardiness, although scarce in land snails, have shown a seasonal variation in supercooling ability, associated with high temperatures of crystallization (Tc). In the present work, two key environmental factors, temperature and photoperiod,(More)
Freezing hardiness in ectotherms has often been separated into two categories, freezing tolerance and freezing susceptibility. But more complex classifications have also been proposed. Helix aspersa hibernates in Brittany during winter. It has a high temperature of crystallisation (between -1.2( and -7.4 degrees C) and survives only few hours at freezing(More)
The land snail Helix pomatia (Gastropoda: Helicidae) is widely distributed in Northern and Central Europe where it may experience subzero temperatures during winter months. Its supercooling ability was studied in two populations of H. pomatia. One population originated from Southern Sweden (Gotaland) and the other from Central France (Auvergne). In the(More)
The land snail Helix aspersa can be considered partially tolerant to freezing, in the sense it can survive some ice formation within its body for a limited time, and possesses a limited ability to supercool. This study aimed at understanding what factors are responsible for the variation of the temperature of crystallization (Tc) in a littoral temperate(More)
The land snail Cornu aspersum (syn. Helix aspersa) living in Brittany (France) can be considered partially freezing tolerant as it possesses a low ability to supercool and a limited capacity to bear freezing of its body tissues. The absence of a marked cold hardiness strategy permits the emphasis of the role of parameters such as individual size or water(More)
Tolerance of ectothermic animals to freezing is often estimated by assessing survival a few days after the treatment. However, in the long term, ice formation in the body tissues can affect survival, as well as reproductive capability and growth. The land snail Helix aspersa survives only short durations with ice in its tissues, to a lethal limit of 40 to(More)
Dispersal decisions are often condition-dependent, influenced by the interaction of individual phenotype and environmental conditions. Terrestrial Gastropods are simultaneous hermaphrodites, a reproductive system rarely studied in the context of dispersal. Moreover, the energetic cost of their movement is one of the highest among animals. Despite these(More)
The main purpose of this article is to study potential biological effects of low-power millimeter waves (MMWs) on endoplasmic reticulum (ER), an organelle sensitive to a wide variety of environmental insults and involved in a number of pathologies. We considered exposure frequencies around 60 GHz in the context of their near-future applications in wireless(More)
Intra- and interspecific differences in movement behaviour play an important role in the ecology and evolution of animals, particularly in fragmented landscapes. As a consequence of rarer and generally more fragmented habitat, and because dispersal tends to disrupt benefits brought by local adaptation, theory predicts that mobility and dispersal should be(More)
Body water is a major element of the cold-hardiness strategies observed in ectothermic animals, in particular in freezing avoidant species for which body ice formation is lethal. Here, we investigate the relationships, in terrestrial snails, between the temperature of crystallisation (Tc) and body water (water mass and water content), shell shape,(More)