| 11. |
- Weeks, Andrew R., et al.
(författare)
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Assessing the benefits and risks of translocations in changing environments : a genetic perspective
- 2011
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 4:6, s. 709-725
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Tidskriftsartikel (refereegranskat)abstract
- Translocations are being increasingly proposed as a way of conserving biodiversity, particularly in the management of threatened and keystone species, with the aims of maintaining biodiversity and ecosystem function under the combined pressures of habitat fragmentation and climate change. Evolutionary genetic considerations should be an important part of translocation strategies, but there is often confusion about concepts and goals. Here, we provide a classification of translocations based on specific genetic goals for both threatened species and ecological restoration, separating targets based on ‘genetic rescue’ of current population fitness from those focused on maintaining adaptive potential. We then provide a framework for assessing the genetic benefits and risks associated with translocations and provide guidelines for managers focused on conserving biodiversity and evolutionary processes. Case studies are developed to illustrate the framework.
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| 12. |
- Baird, Emily, et al.
(författare)
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Bearing selection in ball-rolling dung beetles: is it constant?
- 2010
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Ingår i: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology. - : Springer Science and Business Media LLC. - 1432-1351. ; 196, s. 801-806
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Tidskriftsartikel (refereegranskat)abstract
- Ball rolling in dung beetles is thought to have evolved as a means to escape intense inter- and intra-specific competition at the dung pile. Accordingly, dung beetles typically roll along a straight-line path away from the pile, this being the most effective escape strategy for transporting dung to a suitable burial site. In this study, we investigate how individual diurnal dung beetles, Scarabaeus (Kheper) nigroaeneus, select the compass bearing of their straight-line rolls. In particular, we examine whether roll bearings are constant with respect to geographic cues, celestial cues, or other environmental cues (such as wind direction). Our results reveal that the roll bearings taken by individual beetles are not constant with respect to geographic or celestial references. Environmental cues appear to have some influence over bearing selection, although the relationship is not strong. Furthermore, the variance in roll bearing that we observe is not affected by the presence or absence of other beetles. Thus, rather than being constant for individual beetles, bearing selection varies each time a beetle makes a ball and rolls it away from the dung pile. This strategy allows beetles to make an efficient escape from the dung pile while minimizing the chance of encountering competition.
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| 13. |
- Baird, Emily, et al.
(författare)
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The dung beetle dance: an orientation behaviour?
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- An interesting feature of dung beetle behaviour is that once they have formed a piece of dung into a ball, they roll it along a straight path away from the dung pile. This straight-line orientation ensures that the beetles depart along the most direct route, guaranteeing that they will not return to the intense competition (from other beetles) that occurs near the dung pile. Before rolling a new ball away from the dung pile, dung beetles perform a characteristic "dance," in which they climb on top of the ball and rotate about their vertical axis. This dance behaviour can also be observed during the beetles' straight-line departure from the dung pile. The aim of the present study is to investigate the purpose of the dung beetle dance. To do this, we explored the circumstances that elicit dance behaviour in the diurnal ball-rolling dung beetle, Scarabaeus (Kheper) nigroaeneus. Our results reveal that dances are elicited when the beetles lose control of their ball or lose contact with it altogether. We also find that dances can be elicited by both active and passive deviations of course and by changes in visual cues alone. In light of these results, we hypothesise that the dung beetle dance is a visually mediated mechanism that facilitates straight-line orientation in ball-rolling dung beetles by allowing them to 1) establish a roll bearing and 2) return to this chosen bearing after experiencing a disturbance to the roll path.
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| 14. |
- Burgess, J. Michael, et al.
(författare)
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AN OBSERVED CORRELATION BETWEEN THERMAL AND NON-THERMAL EMISSION IN GAMMA-RAY BURSTS
- 2014
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Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 784:2
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Tidskriftsartikel (refereegranskat)abstract
- Recent observations by the Fermi Gamma-ray Space Telescope have confirmed the existence of thermal and non-thermal components in the prompt photon spectra of some gamma-ray bursts (GRBs). Through an analysis of six bright Fermi GRBs, we have discovered a correlation between the observed photospheric and non-thermal gamma-ray emission components of several GRBs using a physical model that has previously been shown to be a good fit to the Fermi data. From the spectral parameters of these fits we find that the characteristic energies, E-p and kT, of these two components are correlated via the relation E-p proportional to T-alpha which varies from GRB to GRB. We present an interpretation in which the value of the index alpha indicates whether the jet is dominated by kinetic or magnetic energy. To date, this jet composition parameter has been assumed in the modeling of GRB outflows rather than derived from the data.
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| 15. |
- Byrne, Brian, et al.
(författare)
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Teacher Effects in Early Literacy Development: Evidence From a Study of Twins
- 2010
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Ingår i: Journal of Educational Psychology. - : Apa American Psychological Association. - 0022-0663 .- 1939-2176. ; 102:1, s. 32-42
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Tidskriftsartikel (refereegranskat)abstract
- It is often assumed that differences in teacher characteristics area major source of variability in childrens educational achievements. We examine this assumption for early literacy achievement by calculating the correlations between pairs of twin children who either shared or did not share a teacher in kindergarten, Grade 1, and Grade 2. Teacher effects-or, more strictly, classroom effects-would show up as higher correlations for same-class than for different-class twin pairs. Same-class correlations were generally higher than different-class correlations.. though not significantly so on most occasions. On the basis of the results, we estimate that the maximum variance accounted for by being assigned to the same or different classrooms is 8%. This is an upper-bound figure for a teacher effect because factors other than teachers may contribute to variation attributable to classroom assignment. We discuss the limitations of the study and draw out some of its educational implications.
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| 16. |
- Byrne, Myles, et al.
(författare)
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VarioML framework for comprehensive variation data representation and exchange
- 2012
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Ingår i: BMC Bioinformatics. - : Springer Science and Business Media LLC. - 1471-2105. ; 13:254
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sharing of data about variation and the associated phenotypes is a critical need, yet variant information can be arbitrarily complex, making a single standard vocabulary elusive and re-formatting difficult. Complex standards have proven too time-consuming to implement. Results: The GEN2PHEN project addressed these difficulties by developing a comprehensive data model for capturing biomedical observations, Observ-OM, and building the VarioML format around it. VarioML pairs a simplified open specification for describing variants, with a toolkit for adapting the specification into one's own research workflow. Straightforward variant data can be captured, federated, and exchanged with no overhead; more complex data can be described, without loss of compatibility. The open specification enables push-button submission to gene variant databases (LSDBs) e. g., the Leiden Open Variation Database, using the Cafe Variome data publishing service, while VarioML bidirectionally transforms data between XML and web-application code formats, opening up new possibilities for open source web applications building on shared data. A Java implementation toolkit makes VarioML easily integrated into biomedical applications. VarioML is designed primarily for LSDB data submission and transfer scenarios, but can also be used as a standard variation data format for JSON and XML document databases and user interface components. Conclusions: VarioML is a set of tools and practices improving the availability, quality, and comprehensibility of human variation information. It enables researchers, diagnostic laboratories, and clinics to share that information with ease, clarity, and without ambiguity.
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| 17. |
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| 18. |
- Byrne, P. K., et al.
(författare)
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A sagging-spreading continuum of large volcano structure
- 2013
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Ingår i: Geology. - 0091-7613 .- 1943-2682. ; 41:3, s. 339-342
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Tidskriftsartikel (refereegranskat)abstract
- Gravitational deformation strongly influences the structure and eruptive behavior of large volcanoes. Using scaled analog models, we characterize a range of structural architectures produced by volcano sagging and volcano spreading. These arise from the interplay of variable basement rigidity and volcano-basement (de-)coupling. From comparison to volcanoes on Earth (La Reunion and Hawaii) and Mars (Elysium and Olympus Montes), the models highlight a structural continuum in which large volcanoes throughout the Solar System lie.
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| 19. |
- Byrne, P.K., et al.
(författare)
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A Volcanotectonic Survey of Ascraeus Mons, Mars
- 2011
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 117
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Tidskriftsartikel (refereegranskat)abstract
- Ascraeus Mons is one of the largest volcanoes on Mars. It is replete with well-preserved features that can be used to understand its volcanotectonic evolution. Previous studies of this volcano focused on specific features, and were limited by the quality and coverage of contemporary data. Our objective is to review and enhance the existing developmental model for Ascraeus by considering all endogenic surface features on the volcano. We surveyed the volcano's caldera complex, flank terraces, pit structures, sinuous rilles, arcuate grabens, and small vents. We report the spatial and temporal distributions of these features, appraise their proposed formation mechanisms in light of our mapping results, and propose a detailed geological history for Ascraeus Mons. An initial shield-building phase was followed by the formation of a summit caldera complex and small parasitic cones, while compression due to flexure of the supporting basement led to extensive terracing of the shield flanks. An eruptive hiatus followed, ending with the construction of expansive rift aprons to the northeast and southwest. Against later, extensive flank resurfacing in the late Amazonian, continued flexure formed arcuate grabens concentric to the edifice. Localized eruption and surface flow of a fluid agent (lava and/or water) from within the volcano then produced a population of rilles on the lower flanks. Finally, in a change of flank tectonic regime from compression to extension, pit crater chains and troughs developed on the main shield and rift aprons, eventually coalescing to form large embayments at the northeast and southwest base of the volcano.
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| 20. |
- Dacke, Marie, et al.
(författare)
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How dim is dim? Precision of the celestial compass in moonlight and sunlight.
- 2011
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Ingår i: Philosophical Transactions of the Royal Society B: Biological Sciences. - : The Royal Society. - 1471-2970 .- 0962-8436. ; 366:1565, s. 697-702
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Tidskriftsartikel (refereegranskat)abstract
- Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim-and the polarization pattern too weak-to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision.
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