Inadequate food intake at high temperatures is related to depressed mitochondrial respiratory capacity

Animals, especially ectotherms, are highly sensitive to the temperature of their surrounding environment. Extremely high temperature, for example, induces a decline of average performance of conspecifics within a population, but individual heterogeneity in the ability to cope with elevating temperatures has rarely been studied. In this study, we examined inter-individual variation in feeding ability and consequent growth rate of juvenile brown trout Salmo trutta acclimated to a high temperature (19°C), and investigated the relationship between these metrics of whole-animal performances and among-individual variation in mitochondrial respiration capacity. Food was provided ad libitum yet intake varied ten-fold amongst individuals, resulting in some fish losing weight whilst others continued to grow. Almost half of the variation in food intake was related to variability in mitochondrial capacity: low intake (and hence growth failure) was associated with high leak respiration rates within liver and muscle mitochondria, and a lower coupling of muscle mitochondria. These observations, combined with the inability of fish with low food consumption to increase their intake despite ad libitum food levels, suggest a possible insufficient capacity of the mitochondria for maintaining ATP homeostasis. Individual variation in thermal performance is likely to confer variation in the upper limit of an organism's thermal niche and in turn affect the structure of wild populations in warming environments

Differential effects of food availability on minimum and maximum rates of metabolism

Metabolic rates reflect the energetic cost of living but exhibit remarkable variation among conspecifics, partly as a result of the constraints imposed by environmental conditions. Metabolic rates are sensitive to changes in temperature and oxygen availability, but effects of food availability, particularly on maximum metabolic rates, are not well understood. Here, we show in brown trout (Salmo trutta) that maximum metabolic rates are immutable but minimum metabolic rates increase as a positive function of food availability. As a result, aerobic scope (i.e. the capacity to elevate metabolism above baseline requirements) declines as food availability increases. These differential changes in metabolic rates likely have important consequences for how organisms partition available metabolic power to different functions under the constraints imposed by food availability

Challenges and Opportunities of a Forthcoming Strategic Assessment of the Implications of International Climate Change Mitigation Commitments for Individual Undertakings in Canada

Canada is preparing to initiate a challenging, but potentially ground-breaking, strategic assessment on the implications of its climate change mitigation commitments for project assessments. The strategic assessment is immediately needed to provide project-level guidance for decision makers who will be required under new federal legislation to consider the extent to which each assessed project “contributes to sustainability” and “hinders or contributes to” meeting Canada’s climate commitments. However, Canada, like many other countries, has not yet translated its Paris Agreementclimate commitments into an adequate suite of specific policies, pathways, budgets, and other directives for compliance. Consequently, the climate commitments’ strategic assessment will need to play a fully strategic role—in policy development as well as policy interpretation and elaboration for assessment purposes. This paper outlines the key considerations and required steps for a strategic assessment that fills the policy gap between Paris and projects, and develops guidance centred on a suite of tests for evaluating proposed major projects that may have important effects on Canada’s prospects for meeting its climate commitments

The Paris to Projects Research Initiative

This working paper explores the key components and provisions that need to be incorporated into impact assessment legislation to ensure that assessed undertakings help meet Canadian climate change mitigation commitments and duties. This discussion paper includes a summary that serves as a basic briefing note on the core climate components that should be included in the new federal legislation. It also includes a box presenting the tests for determining an undertaking\u27s contributions to meeting Canada\u27s international climate change mitigation commitments, and a more detailed discussion of implications for the new law

Paris to Projects Research Initiative

This working paper explores the key components and provisions that need to be incorporated into impact assessment legislation to ensure that assessed undertakings help meet Canadian climate change mitigation commitments and duties. This discussion paper includes a summary that serves as a basic briefing note on the core climate components that should be included in the new federal legislation. It also includes a box presenting the tests for determining an undertaking\u27s contributions to meeting Canada\u27s international climate change mitigation commitments, and a more detailed discussion of implications for the new law

Green consumers and public policy: On socially contingent moral motivation

“Green” consumers appear to accept individual responsibility for public good provision. The propensity to take such responsibility may depend on beliefs about others’ behavior, even for consumers motivated by internalized moral norms, not by social sanctions. This can produce multiple equilibria, with either high or low demand for “green” products. Permanent increases in green consumption may be achieved through permanent or temporary taxes, or through advertising that temporarily influences beliefs about others’ behavior or about external effects. If a tax is interpreted as taking responsibility away from the individual, however, taxes can reduce the influence of moral motivation

Étude comparative des coupes transversales des fémurs, tibias et humérus de juvéniles humains, de grands singes africains et d'Au. afarensis : détermination des comportements locomoteurs chez Au. afarensis juvénile.

La morphologie des os longs est affectée par les charges mécaniques qu'ils subissent, telles celles générées par les comportements locomoteurs. Dans ce mémoire, des images de coupes transversales de fémurs, tibias et humérus obtenues par CT-scan ont été analysées pour déterminer la locomotion de l'enfant de Dikika, un Au. afarensis juvénile, en se basant sur des comparaisons d'humains et de grands singes africains. Les résultats indiquent que le fémur de l'enfant de Dikika montre des signes de bipédie, mais ce n'est pas le cas du tibia. Malgré le fait que la forme de l'humérus est très similaire aux grands singes africains, la résistance de celui-ci aux tensions et torsions laissent supposer que l'enfant de Dikika ne pratiquait pas les locomotions typiques des grands singes comme l'arboricolisme ou encore la quadrupédie terrestre. Malgré tout, certains résultats montrent que la morphologie osseuse dépend aussi des processus ontogéniques et de la génétique de chaque taxon.The morphology of long bones is affected by the mechanical loads they incur, such as those generated by locomotor behaviors. In this thesis, the images of cross sections of femora, tibiae and humeri obtained by CT-scan were analyzed to determine the locomotion of the Dikika child, a juvenile Au. afarensis, based on comparisons of humans and African apes. The results indicate that the Dikika child's femur shows signs of bipedalism, although the tibia does not. Despite the fact that the shape of the humerus is very similar to that of great African apes, its bending and torsional strength suggest that the Dikika's child did not practice locomotion typical of great apes such as arboricolism or terrestrial quadrupedism. Nevertheless, some results show that bone morphology also depends on the ontogenetic processes and the genetics of each taxon

BIOMECHANICAL DIFFERENCES DURING LANDING BETWEEN INDIVIDUALS WITH PROXIMAL AND COMBINED DEVIATIONS DURING LATERAL STEP DOWN

We investigated the 3D biomechanical differences during landing between those who have proximal (PRO) only (frontal pelvis drop down) and combined (COM) proximal and distal (frontal pelvis drop down and medial knee displacement to 2nd toe) deviations during the lateral step down (LSD) test. Sixty-one recreational male athletes were assessed and those who met the criteria for the groups were tested in a 3D biomechanical laboratory (bilateral drop jump, unilateral forward and drop jump). We found higher hip abduction in the COM group during bilateral drop landings. The COM group also showed lower peak ground reaction force, higher impact absorption rate and higher knee frontal angular velocity during unilateral landings. Participants with LSD proximal and combined deviations differ on key kinetics during unilateral drop landings and hip kinematics during bilateral drop landings

Statistical properties of energy levels of chaotic systems: Wigner or non-Wigner

For systems whose classical dynamics is chaotic, it is generally believed that the local statistical properties of the quantum energy levels are well described by Random Matrix Theory. We present here two counterexamples - the hydrogen atom in a magnetic field and the quartic oscillator - which display nearest neighbor statistics strongly different from the usual Wigner distribution. We interpret the results with a simple model using a set of regular states coupled to a set of chaotic states modeled by a random matrix.Comment: 10 pages, Revtex 3.0 + 4 .ps figures tar-compressed using uufiles package, use csh to unpack (on Unix machine), to be published in Phys. Rev. Let

Dismantling the Beania magellanica (Busk, 1852) species complex (Bryozoa, Cheilostomata): two new species from European waters

New research on bryozoans has determined that formerly widespread species are in many cases complexes of similar, but distinct, species with more restricted distributions. Notwithstanding, the limits of distribution are still unresolved for many taxa, and occasionally a wide distribution is confirmed. Beania magellanica has been considered a widespread species, distributed throughout the Southern Hemisphere, parts of northern Pacific and Atlantic Oceans and the Mediterranean Sea. This study examines the Magellanic-type material, together with other historic samples and new specimens collected in the western Mediterranean and Adriatic, and for the first time, presents specimens from the European North Atlantic. Morphological comparisons and biometric analysis show the existence of three different species among the specimens studied. A redescription of B. magellanica based on the type specimen is presented, and two new species are described: B. serrata sp. nov. from the Northeast Atlantic and B. mediterranea sp. nov. from the Mediterranean Sea. These results indicate that B. magellanica s.l. is a large complex of species and that most specimens from different parts of the world must be revisedThis research was conducted thanks to the funds granted by the Austrian Science Fund (FWF, project number AP28954-B29). The work of Karine Nascimento and Leandro M. Vieira was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, project numbers 142058/2015-7 and 422563/2016-1) and by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, project number 88881.135517/2016-01). Part of the revision of the samples was supported by the project “Fauna Ibérica: Briozoos II (Familia Cribrilinidae–Familia Watersiporidae)” (CGL2010-22267-C07-02), co-financed by the Ministerio de Economía y Competitividad (Spanish government) and FEDERS