2,965 research outputs found
Into the Light: Diurnality has Evolved Multiple Times in Geckos
Geckos are the only major lizard group consisting mostly of nocturnal species. Nocturnality is presumed to have evolved early in gecko evolution and geckos possess numerous adaptations to functioning in low light and at low temperatures. However, not all gecko species are nocturnal and most diurnal geckos have their own distinct adaptations to living in warmer, sunlit environments. We reconstructed the evolution of gecko activity patterns using a newly generated time-calibrated phylogeny. Our results provide the first phylogenetic analysis of temporal activity patterns in geckos and confirm an ancient origin of nocturnality at the root of the gecko tree. We identify multiple transitions to diurnality at a variety of evolutionary time scales and transitions back to nocturnality occur in several predominantly diurnal clades. The scenario presented here will be useful in reinterpreting existing hypotheses of how geckos have adapted to varying thermal and light environments. These results can also inform future research of gecko ecology, physiology, morphology and vision as it relates to changes in temporal activity patterns
The effects of solar particle events on the middle atmosphere
Solar particle events (SPEs) have been investigated since the late 1960's for possible effects on the middle atmosphere. Solar protons from SPEs produce ionizations, dissociations, dissociative ionizations, and excitations in the middle atmosphere. The production of HO(x) and NO(x) and their subsequent effects on ozone can also be computed using energy deposition and photochemical models. The effects of SPE-produced HO(x) species on the odd nitrogen abundance of the middle atmosphere as well as the SPE-produced long term effects on ozone. Model computations indicate fairly good agreement with ozone data for the SPE-induced ozone depletion caused by NO(y) species connected with the August 1972 SPE. The model computations indicate that NO(y) will not be substantially changed over a solar cycle by SPEs. The changes are mainly at high latitudes and are on time scales of several months, after which the NO(y) drifts back to its ambient levels
Repeated Evolution of Digital Adhesion in Geckos: A Reply to Harrington and Reeder
We published a phylogenetic comparative analysis that found geckos had gained and lost adhesive toepads multiple times over their long evolutionary history (Gamble et al., PLoS One, 7, 2012, e39429). This was consistent with decades of morphological studies showing geckos had evolved adhesive toepads on multiple occasions and that the morphology of geckos with ancestrally padless digits can be distinguished from secondarily padless forms. Recently, Harrington & Reeder (J. Evol. Biol., 30, 2017, 313) reanalysed data from Gamble et al. (PLoS One, 7, 2012, e39429) and found little support for the multiple origins hypothesis. Here, we argue that Harrington and Reeder failed to take morphological evidence into account when devising ancestral state reconstruction models and that these biologically unrealistic models led to erroneous conclusions about the evolution of adhesive toepads in geckos
Structure of C22H36N10O2S2
This is the publisher's version, also available electronically from http://scripts.iucr.org/cgi-bin/paper?S0108270188003920.See article for abstract
Reforming marketing for sustainability: towards a framework for evolved marketing
This paper seeks to provide guidance to the question ‘how can we evolve marketing so that it becomes a force for sustainability?’. Much useful advice has been produced on the how existing norms of marketing can be applied to the topic of sustainability – for example, taking the marketing ‘Ps’ and integrating a sustainability approach into each. Many people on the ground trying to implement ‘Sustainable Marketing’ find that there is much high-level enthusiasm for this kind of change, at a management and strategic level, but this enthusiasm is quelled or blocked when the realities of day-to-day marketing activities are faced. Why is this? We conclude that many of the barriers marketers and organisations face in this respect is due to 1) A misalignment between the perceived role of marketing and sustainability 2) Lack of an agreed definition and structure for evolution that companies can follow and stakeholders can use to hold them accountable. This report therefore starts by looking at the very foundations of modern marketing and where best practice is pointing – both of which have the potential to provide a very suitable base for Sustainable Marketing, but equally they could motivate the opposite. By combining these insights with insights on what is required in order for social, economic and environmental sustainability to be met, we suggest that marketing needs to adopt an approach of ‘guide-an-co-create’ rather than a ‘make-and-sell’ or ‘sense-and-respond’ to its customers and society and put forward a set of 6 foundations that could form the basis of a ‘framework for evolved marketing’. These are: 1) Pursue a relentless focus on understanding and satisfying real primary needs 2) Acknowledge the critical leadership role marketing plays 3) Recognise and build upon relationships 4) Adopt a long-term sustainability mindset 5) Take a rigorous approach to measuring the sustainability of all marketing decisions 6) Put marketing at the heart of all organisational strategic decisions This report is intended to provide the starting point for discussion about if there is support for a framework that might be used in the way a voluntary code might, and if so, are the 6 suggested here the right ones? The hard work then comes when companies work with the framework to innovate their own examples of best practice in each. Through this practice sector level key performance indicators and benchmarks are likely to evolve. By using a question based maturity –matrix style approach (as has been used successfully in other sustainability settings) it will therefore become clear over time, which companies are leading in this area and can make valid claims and those who are not. The framework presented is intended to support organisations in setting their strategic direction so that it is aligned with sustainability though its marketing - which in advanced companies should be driving their strategic direction. It is equally intended to support the journey of those who are doing marketing on a day-to-day basis – both those who formally consider them to be marketers as well as the many, many people who are doing marketing but don’t define themselves in that way. We believe that by providing a common language and common direction for the evolution of marketing, it could become a key driving force for a sustainable future
Atmospheric oxidation chemistry and ozone production: Results from SHARP 2009 in Houston, Texas
This study considers whether spikes in nitrate in snow sampled at Summit, Greenland, from August 2000 to August 2002 are related to solar proton events. After identifying tropospheric sources of nitrate on the basis of correlations with sulfate, ammonium, sodium, and calcium, we use the three-dimensional global Whole Atmosphere Community Climate Model (WACCM) to examine unaccounted for nitrate spikes. Model calculations confirm that solar proton events significantly impact HOx, NOx, and O3 levels in the mesosphere and stratosphere during the weeks and months following the major 9 November 2000 solar proton event. However, solar proton event (SPE)-enhanced NOy calculated within the atmospheric column is too small to account for the observed nitrate peaks in surface snow. Instead, our WACCM results suggest that nitrate spikes not readily accounted for by measurement correlations are likely of anthropogenic origin. These results, consistent with other recent studies, imply that nitrate spikes in ice cores are not suitable proxies for individual SPEs and motivate the need to identify alternative proxies
Nitrate deposition to surface snow at Summit, Greenland, following the 9 November 2000 solar proton event
Abstract This study considers whether spikes in nitrate in snow sampled at Summit, Greenland, from August 2000 to August 2002 are related to solar proton events. After identifying tropospheric sources of nitrate on the basis of correlations with sulfate, ammonium, sodium, and calcium, we use the three-dimensional global Whole Atmosphere Community Climate Model (WACCM) to examine unaccounted for nitrate spikes. Model calculations confirm that solar proton events significantly impact HOx, NOx, and O3 levels in the mesosphere and stratosphere during the weeks and months following the major 9 November 2000 solar proton event. However, solar proton event (SPE)-enhanced NOy calculated within the atmospheric column is too small to account for the observed nitrate peaks in surface snow. Instead, our WACCM results suggest that nitrate spikes not readily accounted for by measurement correlations are likely of anthropogenic origin. These results, consistent with other recent studies, imply that nitrate spikes in ice cores are not suitable proxies for individual SPEs and motivate the need to identify alternative proxies. Key Points A global model simulates nitrate deposition from solar proton events Soluble ion correlations in Summit snow identify tropospheric sources of nitrate Nitrate ions in snow are found not to be a good proxy for solar proton events
Coming to America: Multiple Origins of New World Geckos
Geckos in the Western Hemisphere provide an excellent model to study faunal assembly at a continental scale. We generated a time-calibrated phylogeny, including exemplars of all New World gecko genera, to produce a biogeographic scenario for the New World geckos. Patterns of New World gecko origins are consistent with almost every biogeographic scenario utilized by a terrestrial vertebrate with different New World lineages showing evidence of vicariance, dispersal via temporary land bridge, overseas dispersal, or anthropogenic introductions. We also recovered a strong relationship between clade age and species diversity, with older New World lineages having more species than more recently arrived lineages. Our data provide the first phylogenetic hypothesis for all New World geckos and highlight the intricate origins and ongoing organization of continental faunas. The phylogenetic and biogeographical hypotheses presented here provide an historical framework to further pursue research on the diversification and assembly of the New World herpetofauna
Ethical and compliance-competence evaluation: a key element of sound corporate governance
Motivated by the ongoing post-Enron refocusing on corporate governance and the shift by the Financial Services Authority (FSA) in the UK to promoting compliance- competence within the financial services sector, this paper demonstrates how template analysis can be used as a tool for evaluating compliance-competence. Focusing on the ethical dimension of compliance-competence, we illustrate how this can be subjectively appraised. We propose that this evaluation technique could be utilised as a starting point in informing senior management of corporate governance issues and be used to monitor and demonstrate key compliance and ethical aspects of an institution to external stakeholders and regulators
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