155 research outputs found
Interactions between downslope flows and a developing cold-air pool
A numerical model has been used to characterize the development of a region of enhanced cooling in an alpine valley with a width of order (Formula presented.) km, under decoupled stable conditions. The region of enhanced cooling develops largely as a region of relatively dry air which partitions the valley atmosphere dynamics into two volumes, with airflow partially trapped within the valley by a developing elevated inversion. Complex interactions between the region of enhanced cooling and the downslope flows are quantified. The cooling within the region of enhanced cooling and the elevated inversion is almost equally partitioned between radiative and dynamic effects. By the end of the simulation, the different valley atmospheric regions approach a state of thermal equilibrium with one another, though this cannot be said of the valley atmosphere and its external environment.Peer reviewe
Interactions between the night time valley-wind system and a developing cold-air pool
This is a pre-copyedited, author-produced PDF of an article accepted for publication in Boundary-Layer Meteorology following peer review. The version of record [Arduini, G., Staquet, C & Chemel, C., ‘Interactions between the night time valley-wind system and a developing cold-air pool’, Boundary-Layer Meteorol (2016) 161:1 (49-72), first published online June 2, 2016, is available at Springer online at doi: 10.1007/s10546-016-0155-8The Weather Research and Forecast (WRF) numerical model is used to characterize the influence of a thermally-driven down-valley flow on a developing cold-air pool in an idealized alpine valley decoupled from the atmosphere above. Results for a three-dimensional (3D) valley, which allows for the formation of a down-valley flow, and for a two-dimensional (2D) valley, where the formation of a down-valley flow is inhibited, are analyzed and compared. A key result is that advection leads to a net cooling in the 2D valley and to a warming in the 3D valley, once the down-valley flow is fully developed. This difference stems from the suppression of the slope-flow induced upward motions over the valley centre in the 3D valley. As a result, the downslope flows develop a cross-valley circulation within the cold-air pool, the growth of the cold-air pool is reduced and the valley atmosphere is generally warmer than in the 2D valley. A quasi-steady state is reached for which the divergence of the down-valley flow along the valley is balanced by the convergence of the downslope flows at the top of the cold-air pool, with no net contribution of subsiding motions far from the slope layer. More precisely, the inflow of air at the top of the cold-air pool is found to be driven by an interplay between the return flow from the plain region and subsidence over the plateaux. Finally, the mechanisms that control the structure of the cold-air pool and its evolution are found to be independent of the valley length as soon as the quasi-steady state is reached and the down-valley flow is fully developed.Peer reviewedFinal Accepted Versio
Challenges Using Extrapolated Family-level Macroinvertebrate Metrics in Moderately Disturbed Tropical Streams: a Case-study From Belize
Family-level biotic metrics were originally designed to rapidly assess gross organic pollution effects, but came to be regarded as general measures of stream degradation. Improvements in water quality in developed countries have reignited debate about the limitations of family-level taxonomy to detect subtle change, and is resulting in a shift back towards generic and species-level analysis to assess smaller effects. Although the scale of pollution characterizing past condition of streams in developed countries persists in many developing regions, some areas are still considered to be only moderately disturbed. We sampled streams in Belize to investigate the ability of family-level macroinvertebrate metrics to detect change in stream catchments where less than 30% of forest had been cleared. Where disturbance did not co-vary with natural gradients of change, and in areas characterized by low intensity activities, none of the metrics tested detected significant change, despite evidence of environmental impacts. We highlight the need for further research to clarify the response of metrics to disturbance over a broader study area that allows replication for confounding sources of natural variation. We also recommend research to develop more detailed understanding of the taxonomy and ecology of Neotropical macroinvertebrates to improve the robustness of metric use
A qualitative study of the understanding and use of ‘compassion focused coping strategies’ in people who suffer from serious weight difficulties.
Abstract Background The physical and psychological health problems associated with obesity are now well documented, as is the urgency for addressing them. In addition, associations between quality of life, depression, self-esteem, self-criticism, and obesity are now established indicating a need for a better understanding of the links between self-evaluation, affect-regulation and eating behaviours. Methods Compassion has now been identified as a major source of resilience, helpful self-relating and affect regulation. Thus this study used semi-structured interviews to explore the understanding and experiences of compassion in 2 overweight men and 10 women seeking help for weight problems. The interviews examined people's understandings of compassion, their recall of experiences of compassion in childhood, their current experiences of receiving compassion from others, being compassionate to others, being self-compassionate, and whether they would be compassionate or self-critical for relapses in overeating. Interviews were transcribed and analysed using thematic analysis (Qual Res Psychol, 3: 77-101, 2006). Results Participants saw compassion as related to ‘caring’ and being ‘listened to’. However, their recall of earlier experiences of compassion was of primarily practical help rather than emotional engagement. Typically their response to their own relapse and setbacks were self-criticism, self-disgust and even self-hatred rather than self-caring or understanding. Self-critical/hating responses tend to be associated with poor weight regulation. Conclusions When people with weight problems relapse, or struggle to control their eating, they can become quite self-critical, even self-hating, which may increase difficulties with emotionally coping and maintaining healthy lifestyles and eating habits. Although turning to others for support and compassion, and becoming self-compassionate are antidotes to self-criticism, and are associated with better coping and mental health, many participants did not utilise compassionate strategies – often the opposite. It is possible that interventions that include mindfulness and compassion training could be helpful for these difficulties.N/
Whole-genome cancer analysis as an approach to deeper understanding of tumour biology
Recent advances in DNA sequencing technology are providing unprecedented opportunities for comprehensive analysis of cancer genomes, exomes, transcriptomes, as well as epigenomic components. The integration of these data sets with well-annotated phenotypic and clinical data will expedite improved interventions based on the individual genomics of the patient and the specific disease
Habitat use at fine spatial scale: how does patch clustering criteria explain the use of meadows by red deer ?
Large mammalian herbivores are keystone species
in different ecosystems. To mediate the effects of large
mammalian herbivores on ecosystems, it is crucial to understand
their habitat selection pattern. At finer scales, herbivore
patch selection depends strongly on plant community
traits and therefore its understanding is constrained by patch
definition criteria. Our aim was to assess which criteria for
patch definition best explained use of meadows by wild,
free-ranging, red deer (Cervus elaphus) in a study area in
Northeast Portugal. We used two clustering criteria types
based on floristic composition and gross forage classes, respectively.
For the floristic criteria, phytosociological approach
was used to classify plant communities, and its
objectivity evaluated with a mathematical clustering of the
floristic relevés. Cover of dominant plant species was tested
as a proxy for the phytosociological method. For the gross
forage classes, the graminoids/forbs ratio and the percentage
cover of legumes were used. For assessing deer relative use of
meadows we used faecal accumulation rates. Patches clustered
according to floristic classification better explained selection of patches by deer. Plant community classifications based on
phytosociology, or proxies of this, used for characterizing
meadow patches resulted useful to understand herbivore selection
pattern at fine scales and thus potentially suitable to
assist wildlife management decisions
Nest desertion is not predicted by cuckoldry in the Eurasian penduline tit
Engagement in extra-pair copulations is an example of the abundant conflicting interests between males and females over reproduction. Potential benefits for females and the risk of cuckoldry for males are expected to have important implications on the evolution of parental care. However, whether parents adjust parental care in response to parentage remains unclear. In Eurasian penduline tits Remiz pendulinus, which are small polygamous songbirds, parental care is carried out either by the male or by the female. In addition, one third of clutches is deserted by both male and female. Desertion takes place during the egg-laying phase. Using genotypes of nine microsatellite loci of 443 offspring and 211 adults, we test whether extra-pair paternity predicts parental care. We expect males to be more likely to desert cuckolded broods, whereas we expect females, if they obtain benefits from having multiple sires, to be more likely to care for broods with multiple paternity. Our results suggest that parental care is not adjusted to parentage on an ecological timescale. Furthermore, we found that male attractiveness does not predict cuckoldry, and we found no evidence for indirect benefits for females (i.e., increased growth rates or heterozygosity of extra-pair offspring). We argue that male Eurasian penduline tits may not be able to assess the risk of cuckoldry; thus, a direct association with parental care is unlikely to evolve. However, timing of desertion (i.e., when to desert during the egg-laying phase) may be influenced by the risk of cuckoldry. Future work applying extensive gene sequencing and quantitative genetics is likely to further our understanding of how selection may influence the association between parentage and parental care
Arabidopsis COP1 shapes the temporal pattern of CO accumulation conferring a photoperiodic flowering response
The transcriptional regulator CONSTANS (CO) promotes flowering of Arabidopsis under long summer days (LDs) but not under short winter days (SDs). Post-translational regulation of CO is crucial for this response by stabilizing the protein at the end of a LD, whereas promoting its degradation throughout the night under LD and SD. We show that mutations in CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a component of a ubiquitin ligase, cause extreme early flowering under SDs, and that this is largely dependent on CO activity. Furthermore, transcription of the CO target gene FT is increased in cop1 mutants and decreased in plants overexpressing COP1 in phloem companion cells. COP1 and CO interact in vivo and in vitro through the C-terminal region of CO. COP1 promotes CO degradation mainly in the dark, so that in cop1 mutants CO protein but not CO mRNA abundance is dramatically increased during the night. However, in the morning CO degradation occurs independently of COP1 by a phytochrome B-dependent mechanism. Thus, COP1 contributes to day length perception by reducing the abundance of CO during the night and thereby delaying flowering under SDs
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