|
|
. (2018). Do glucocorticoids mediate the link between environmental conditions and telomere dynamics in wild vertebrates? A review (Vol. 256). Bachelor's thesis, , .
Abstract: Following the discoveries of telomeres and of their implications in terms of health and ageing, there has been a growing interest into the study of telomere dynamics in wild vertebrates. Telomeres are repeated sequences of non-coding DNA located at the terminal ends of chromosomes and they play a major role in maintaining chromosome stability. Importantly, telomeres shorten over time and shorter telomeres seem to be related with lower survival in vertebrates. Because of this potential link with longevity, it is crucial to understand not only the ecological determinants of telomere dynamics but also the regulatory endocrine mechanisms that may mediate the effect of the environment on telomeres. In this paper, we review the relationships that link environmental conditions, glucocorticoids (GC, the main hormonal mediator of allostasis) and telomere length in vertebrates. First, we review current knowledge about the determinants of inter-individual variations in telomere length. We emphasize the potential strong impact of environmental stressors and predictable life-history events on telomere dynamics. Despite recent progress, we still lack crucial basic data to fully understand the costs of several life-history stages and biotic and abiotic factors on telomere length. Second, we review the link that exists between GCs, oxidative stress and telomere dynamics in vertebrates. Although circulating GC levels may be closely and functionally linked with telomere dynamics, data are still scarce and somewhat contradictory. Further laboratory and field studies are therefore needed not only to better assess the proximate link between GC levels and telomere dynamics, but also to ultimately understand to what extent GCs and telomere length could be informative to measure the fitness costs of specific life-history stages and environmental conditions. Finally, we highlight the importance of exploring the functional links that may exist between coping styles, the GC stress response, and telomere dynamics in a life-history framework. To conclude, we raise new hypotheses regarding the potential of the GC stress response to drive the trade-off between immediate survival and telomere protection.
Keywords: Corticosterone Cortisol HPA axis Oxidative stress Stress Telomerase Telomere
Programme: 109,330
|
|
|
|
. (2014). Physiological and fitness correlates of experimentally altered hatching asynchrony magnitude in chicks of a wild seabird
. Gen. Comp. Endocrinol., 198, 32–38.
Keywords: Aggression, Corticosterone, Hatching asynchrony, Sexual dimorphism, Sibling competition,
Programme: 330,1162
|
|
|
|
Thierry Boulinier. (2023). Avian influenza spread and seabird movements between colonies (Vol. 38). Bachelor's thesis, , .
Keywords: colonial breeding foraging HPAI H5N1 migration movement ecology prospecting spatial disease dynamics
Programme: 333,1151
|
|
|
|
. (2011). Tectonophysics, 498(14), 11–26.
Keywords: South Iceland Seismic Zone, Transform zone, Paleoseismic fault, Fault segmentation, Offset fault vs. earthquake magnitude, Riedel-type fault pattern,
Programme: 316
|
|
|
|
. (2019). CameraTransform: A Python package for perspective corrections and image mapping (Vol. 10). Bachelor's thesis, , .
Keywords: Camera lens distortions Geo-referencing Perspective projection Quantitative image analysis
Programme: 137
|
|
|
|
. (2022). Mercury contamination and potential health risks to Arctic seabirds and shorebirds (Vol. 844). Bachelor's thesis, , .
Keywords: Arctic Birds Mercury Toxicity benchmarks Toxicological effects
Programme: 330,388,1036,1210
|
|
|
|
. (2022). Temporal trends of mercury in Arctic biota: 10 more years of progress in Arctic monitoring (Vol. 839). Bachelor's thesis, , .
Keywords: Arctic Biota Environmental monitoring Mercury Statistical assessment Temporal trends
Programme: 330,388
|
|
|
|
Macelloni Giovanni, Leduc-Leballeur Marion, Brogioni Marco, Ritz Catherine, Picard Ghislain, . (2016). Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau. REMOTE SENSING OF ENVIRONMENT, 180, 193–204.
Abstract: The SMOS brightness temperature (TB) collected on the East Antarctic Plateau revealed spatial signatures at L-band that have never before been observed when only higher-frequency passive microwave observations were available, and this has opened up a new field of research. Because of the much greater penetration depth, modeling the microwave ice sheet emission requires taking into account not only snow conditions on the surface, but should also include glaciological information. Even if the penetration depth of the L-band is not well known due to the uncertainty on the imaginary part of the ice permittivity, it is likely to be of the order of several hundreds of meters, which means that the temperature of the ice over a depth of nearly 1000 m influences the emission. Over such a depth, the temperature is related to both the surface conditions and to the ice sheet thickness, which in turn depends on the bedrock topography and on other glaciological variables. The present paper aims to provide a thorough theoretical explanation of the observed TB spatial variation close to the Brewster angle at vertical polarization, in order to limit the effect of surface and vertical density variability in the firn. In order to provide reliable inputs to the microwave emission models used for simulating TB data, an in-depth analysis of the temperature profiles was performed by means of glaciological models. The comparison between simulated and observed data over three transects totalling 2000 km in East Antarctica pointed out that, whereas the emission models are capable of explaining the TB spatial variations of several kelvins (0.7 and 2.9 K), they are unable to predict its absolute value correctly. This study also shows that the main limiting factor in simulating low-frequency microwave data is the uncertainty in the currently available imaginary part of the ice permittivity.
Keywords: Antarctica, Ice sheet temperature, Microwave emission model, SMOS,
Programme: 902,1110
|
|
|
|
. (2020). Holocene dynamics of the southern westerly winds over the Indian Ocean inferred from a peat dust deposition record (Vol. 231). Bachelor's thesis, , .
Keywords: Amsterdam Island Anthropogenic activities Dust sources Peat Southern westerly winds
Programme: 1065,1133
|
|
|
|
. (2019). Molar shape differentiation during range expansions of the collared lemming (Dicrostonyx torquatus) related to past climate changes (Vol. 221). Bachelor's thesis, , .
Abstract: The genus Dicrostonyx (the collared lemming) is undoubtedly the small mammal best adapted to the extreme conditions of the arctic environment. The Palearctic collared lemming has been described in numerous European Late Pleistocene localities up to south of France and Croatia. This species experienced climate-driven changes through time, changes mainly observed as repetitive pulses of pan-continental migration, and it thus became a typical indicator of glacial conditions. Using geometric morphometrics on molars, we evaluate the shape changes occurring during the last 100 ky over some dispersal events in Western Europe. The results point out that Dicrostonyx torquatus has a large intra-population variation with a homogenous morphology, regardless of the origin of the individuals. A temporal trend leading to a more complex tooth with a differentiated anterior loop on the first lower molar was observed. An additional effect of the distance from the core populations was also described with a more peculiar shape for the most western populations of France. These temporal and geographical trends might relate to the different migratory pulses documented from ancient DNA haplotypes.
Keywords: Climate Collared lemmings Geometric morphometrics Range expansion
Programme: 1036
|
|
