Behavioural and physiological adaptations to low-temperature environments in the common frog, Rana temporaria

<b>Background</b><p></p> Extreme environments can impose strong ecological and evolutionary pressures at a local level. Ectotherms are particularly sensitive to low-temperature environments, which can result in a reduced activity period, slowed physiological processes and increased exposure to sub-zero temperatures. The aim of this study was to assess the behavioural and physiological responses that facilitate survival in low-temperature environments. In particular, we asked: 1) do high-altitude common frog (Rana temporaria) adults extend the time available for larval growth by breeding at lower temperatures than low-altitude individuals?; and 2) do tadpoles sampled from high-altitude sites differ physiologically from those from low-altitude sites, in terms of routine metabolic rate (RMR) and freeze tolerance? Breeding date was assessed as the first day of spawn observation and local temperature recorded for five, paired high- and low-altitude R. temporaria breeding sites in Scotland. Spawn was collected and tadpoles raised in a common laboratory environment, where RMR was measured as oxygen consumed using a closed respiratory tube system. Freeze tolerance was measured as survival following slow cooling to the point when all container water had frozen.<p></p> <b>Results</b><p></p> We found that breeding did not occur below 5°C at any site and there was no significant relationship between breeding temperature and altitude, leading to a delay in spawning of five days for every 100 m increase in altitude. The relationship between altitude and RMR varied by mountain but was lower for individuals sampled from high- than low-altitude sites within the three mountains with the highest high-altitude sites (≥900 m). In contrast, individuals sampled from low-altitudes survived freezing significantly better than those from high-altitudes, across all mountains.<p></p> <b>Conclusions</b><p></p> Our results suggest that adults at high-altitude do not show behavioural adaptations in terms of breeding at lower temperatures. However, tadpoles appear to have the potential to adapt physiologically to surviving at high-altitude via reduced RMR but without an increase in freeze tolerance. Therefore, survival at high-altitude may be facilitated by physiological mechanisms that permit faster growth rates, allowing completion of larval development within a shorter time period, alleviating the need for adaptations that extend the time available for larval growth

Sellafield-derived anthropogenic C-14 in the marine intertidal environment of the NE Irish Sea

The intertidal biota from Parton beach, close to the Sellafield nuclear fuel reprocessing plant, were all found to be enriched in radiocarbon relative to ambient background. The degree of enrichment appears to reflect the positions of the biota in the food chain once the dilution in seaweed from atmospheric uptake is taken into account. Close to the low-water mark, the order was mussels gt limpets gt anemones congruent to winkles gt seaweed. The same order was observed close to the high-water mark, except that anemones were absent from this area. The activities in the biogeochemical fractions of the water column reflect the fact that discharges are primarily in the form of dissolved inorganic carbon (DIC), which is subsequently transferred to the particulate organic carbon (POC) and, to a lesser extent, the dissolved organic carbon (DOC), and finally, the particulate inorganic carbon (PIC). Analysis of intertidal sediment suggests that there is likely to be a gradual increase in the specific activity of C-14 in the inorganic component of this material as Sellafield contaminated organisms die and their shells are ground down by natural processes

A Decision Making Model for the Adoption of Cloud Computing in Jamaican Organizations

Cloud computing is the current technological silver bullet that has been proposed for solving a variety of Information Systems (IS) problems facing organizations in developing countries including bridging the digital divide. However, the large number of cloud options available can make determining the most applicable solution to an organization non-trivial. This paper looks at these options and the barriers to adoption facing Small/Medium Enterprises (SMEs) in Jamaica. A Simple Additive Weighting (SAW) model which can be used in the cloud adoption decision process is then developed and tested using an example

Bounds on minors of binary matrices

We prove an upper bound on sums of squares of minors of {+1, -1} matrices. The bound is sharp for Hadamard matrices, a result due to de Launey and Levin (2009), but our proof is simpler. We give several corollaries relevant to minors of Hadamard matrices, and generalise a result of Turan on determinants of random {+1,-1} matrices.Comment: 9 pages, 1 table. Typo corrected in v2. Two references and Theorem 2 added in v

Forced and Aeroelastic Responses of Bird-Damaged Fan Blades: A Comparison and Its Implications

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140641/1/1.C033424.pd

Good People, Bad Job Situations: A Middle Manager\u27s Dilemma

Middle managers play a critical role in successful library operations in both public and academic settings. Their alignment with and their ability to carry out the vision of upper management is critical to moving the organization forward at all levels. The authors offer practical strategies for any middle manager who finds herself in a position where she is not in accord with her boss, situations that can range from uncomfortable to disastrous. They examine a variety of issues and circumstances such as misunderstandings, unanticipated changes in the organization, lack of fit with the organizational culture, different work expectations, and incompatible work styles that lead to conflicts and challenges between the middle manager and her boss. Because the library management literature does not address this area well, the authors suggest approaches for coping, determining possible exit strategies as well as behaviors to avoid. The recommendations are based on reading management literature from a range of other sources and from personal experiences

Aeroelastic Response of Bird-Damaged Fan Blades Using a Coupled CFD/CSD Framework

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140712/1/6.2014-0334.pd