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The purpose of this study was to examine whether vehicle type based on size (car vs. other = truck/van/SUV) had an impact on the speeding, acceleration, and braking patterns of older male and female drivers (70 years and older) from a Canadian longitudinal study. The primary hypothesis was that older adults driving larger vehicles (e.g., trucks, SUVs, or vans) would be more likely to speed than those driving cars. Participants (n = 493) had a device installed in their vehicles that recorded their everyday driving. The findings suggest that the type of vehicle driven had little or no impact on per cent of time speeding or on the braking and accelerating patterns of older drivers. Given that the propensity for exceeding the speed limit was high among these older drivers, regardless of vehicle type, future research should examine what effect this behaviour has on older-driver road safety.
Understanding why ecological communities contain the species they do is a long-standing question in ecology. Two common mechanisms that affect the species found within communities are dispersal limitation and environmental filtering. Correctly identifying the relative influences of these mechanisms has important consequences for our understanding of community assembly. Here variable selection was used to identify the environmental variables that best predict tropical forest primate community similarity in four biogeographic regions: the Neotropics, Afrotropics, Madagascar and the island of Borneo in South-East Asia. The environmental variables included net primary productivity and altitude, as well as multiple temperature, precipitation and topsoil variables. Using the best environmental variables in each region, Mantel and partial Mantel tests were used to reanalyse data from a previously published study. The proportion of variance explained increased for each region. Despite increases, much of the variation remained unexplained for all regions (R2: Africa = 0.45, South America = 0.16, Madagascar = 0.28, Borneo = 0.10), likely due to different evolutionary and biogeographic histories within each region. Nonetheless, substantial variation among regions in the environmental variables that best predicted primate community similarity were documented. For example, none of the 14 environmental variables was included for all four regions, yet each variable was included for at least one region. Contrary to prior results, environmental filtering was an important assembly mechanism for primate communities in tropical forests worldwide. Geographic distance more strongly predicted African and South American communities whereas environmental distance more strongly predicted Malagasy and Bornean communities. These results suggest that dispersal limitation structures primate communities more strongly than environmental filtering in Africa and in South America whereas environmental filtering structures primate communities more strongly than dispersal limitation in Madagascar and Borneo. For communities defined by genera, environmental distance more strongly predicted primate communities than geographic distance in all four regions, which suggests that environmental filtering is a more influential assembly mechanism at the genus level. Therefore, a more nuanced consideration of environmental variables affects conclusions about the influences of environmental filtering and dispersal limitation on primate community structure.
Background: High comorbidity rates among emotional disorders have led researchers to examine transdiagnostic factors that may contribute to shared psychopathology. Bifactor models provide a unique method for examining transdiagnostic variables by modelling the common and unique factors within measures. Previous findings suggest that the bifactor model of the Depression Anxiety and Stress Scale (DASS) may provide a method for examining transdiagnostic factors within emotional disorders. Aims: This study aimed to replicate the bifactor model of the DASS, a multidimensional measure of psychological distress, within a US adult sample and provide initial estimates of the reliability of the general and domain-specific factors. Furthermore, this study hypothesized that Worry, a theorized transdiagnostic variable, would show stronger relations to general emotional distress than domain-specific subscales. Method: Confirmatory factor analysis was used to evaluate the bifactor model structure of the DASS in 456 US adult participants (279 females and 177 males, mean age 35.9 years) recruited online. Results: The DASS bifactor model fitted well (CFI = 0.98; RMSEA = 0.05). The General Emotional Distress factor accounted for most of the reliable variance in item scores. Domain-specific subscales accounted for modest portions of reliable variance in items after accounting for the general scale. Finally, structural equation modelling indicated that Worry was strongly predicted by the General Emotional Distress factor. Conclusions: The DASS bifactor model is generalizable to a US community sample and General Emotional Distress, but not domain-specific factors, strongly predict the transdiagnostic variable Worry.
The purpose of this study was to determine if season or weather affected the objectively measured trip distances of older drivers (≥ 70 years; n = 279) at seven Canadian sites. During winter, for all trips taken, trip distance was 7 per cent shorter when controlling for site and whether the trip occurred during the day. In addition, for trips taken within city limits, trip distance was 1 per cent shorter during winter and 5 per cent longer during rain when compared to no precipitation when controlling for weather (or season respectively), time of day, and site. At night, trip distance was about 30 per cent longer when controlling for season and site (and weather), contrary to expectations. Together, these results suggest that older Canadian drivers alter their trip distances based on season, weather conditions, and time of day, although not always in the expected direction.
The whale shark Rhincodon typus is a popular focal species in the marine tourism industry. We analysed 689 encounters with at least 142 individual sharks during 2008–2010 to assess their behaviour in the presence of swimmers at Tofo Beach, Mozambique. Sharks varied in size (estimated 3.0–9.5 m total length) and the majority (74%) were males. The sharks displayed avoidance behaviours during 64.7% of encounters. Encounter duration decreased significantly, from 12 minutes 37 s with undisturbed sharks to 8 minutes 25 s when sharks expressed avoidance behaviours, indicating that interactions with tourists affected the sharks’ short-term behaviour. However, during the 2.5-year study period we found no trend in the mean encounter duration, the overall expression of avoidance behaviour or the likelihood of an individual shark exhibiting avoidance behaviours. Potential effects of tourism may be mitigated by the non-breeding status and transient behaviour of sharks at this aggregation site.
Conservation interventions increasingly involve active management of relative species abundances, especially when taxa of conservation concern are threatened by complex food web interactions. Unfortunately, the complexity of such interspecific interactions means that well-meaning management interventions can have unexpected, sometimes detrimental, effects on the species they are intended to protect. Here we report that the abrupt removal of an abundant non-native prey species (domestic sheep) and the cessation of predator control, actions intended to protect huemul deer Hippocamelus bisulcus in the future Patagonia National Park, appear to have had negative effects on this Endangered ungulate. During and following the changes in predator–prey management, predation of huemul fawns and females older than 1 year by native culpeo foxes Lycalopex culpaeus and pumas Puma concolor increased 3- and 5-fold, respectively. Predictions from demographic models suggest that elevated mortality rates of female huemul older than 1 year will, on average, cause this population of huemul to decline. These results highlight risks of unintended consequences when aggressive management actions are taken to protect taxa embedded in complex food webs. They also suggest that careful consideration of both inter- and intra-trophic level effects among all species in a system is warranted before conservation interventions are undertaken.
Ecological regions aggregate habitats with similar biophysical characteristics within well-defined boundaries, providing spatially consistent platforms for monitoring, managing and forecasting the health of interrelated ecosystems. A major obstacle to the implementation of this approach is imprecise and inconsistent boundary placement. For globally important mountain regions such as the Eastern Arc (Tanzania and Kenya), where qualitative definitions of biophysical affinity are well established, rule-based methods for landform classification provide a straightforward solution to ambiguities in region extent. The method presented in this paper encompasses the majority of both contemporary and estimated preclearance forest cover within strict topographical limits. Many of the species here tentatively considered ‘near-endemic’ could be reclassified as strictly endemic according to the derived boundaries. LandScan and census data show population density inside the ecoregion to be higher than in rural lowlands, and lowland settlement to be most probable within 30 km. This definition should help to align landscape scale conservation strategies in the Eastern Arc and promote new research in areas of predicted, but as yet undocumented, biological importance. Similar methods could work well in other regions where mountain extent is poorly resolved. Spatial data accompany the online version of this article.
This paper describes the results of two seasons of excavation and associated palaeoenvironmental analyses of a wetland site on Beccles Marshes, Beccles, Suffolk. The site has been identified as a triple post alignment of oak timbers (0.6–2.0 m long), over 100 m in length, and 3–4 m wide, running north-west to south-east towards the River Waveney. It was constructed in a single phase which has been dated dendrochronologically to 75 BC, although discrete brushwood features identified as possible short trackways have been dated by radiocarbon to both before and after the alignment was built. It is unclear if the posts ever supported a superstructure but notches (‘halving lap joints’) in some of the posts appear to have held timbers to support the posts and/or aid in their insertion. In addition, fragments of both Iron Age and Romano-British pottery were recovered. A substantial assemblage of worked wooden remains appears to reflect the construction of the post row itself and perhaps the on-site clearance of floodplain vegetation. This assemblage also contains waste material derived from the reduction splitting of timbers larger than the posts of the alignment, but which have not been recovered from the site. Environmental analyses indicate that the current landscape context of the site with respect to the River Waveney is probably similar to that which pertained in prehistory. The coleoptera (beetle) record illustrates a series of changes in the on-site vegetation in the period before, during and after the main phase of human activity which may be related to a range of factors including floodplain hydrology and anthropogenic utilisation of Beccles Marshes. The possible form and function of the site is discussed in relation to the later prehistoric period in Suffolk.
In 2010, Business Ethics Quarterly published ten articles that considered the potential contributions to business ethics research arising from recent scholarship in a variety of philosophical and social scientific fields (strategic management, political philosophy, restorative justice, international business, legal studies, ethical theory, ethical leadership studies, organization theory, marketing, and corporate governance and finance). Here we offer short responses to those articles by members of Business Ethics Quarterly’s editorial board and editorial team.
Nest surveys are widely employed to assess the population density of orang-utans (Pongo spp.) and evaluate alternative management scenarios relevant to the protection of these threatened great apes. However, this method is less accurate and prone to much greater error than is generally acknowledged. Here we highlight the limitations of orang-utan nest surveys, discuss the risks of ignoring these limitations, and note conditions under which standard nest survey methods are appropriate.
In recognition of the fact that orang-utans (Pongo spp.) are severely threatened, a meeting of orang-utan experts and conservationists, representatives of national and regional governmental and non-governmental organizations, and other stakeholders, was convened in Jakarta, Indonesia, in January 2004. Prior to this meeting we surveyed all large areas for which orang-utan population status was unknown. Compilation of all survey data produced a comprehensive picture of orang-utan distribution on both Borneo and Sumatra. These results indicate that in 2004 there were c. 6,500 P. abelii remaining on Sumatra and at least 54,000 P. pygmaeus on Borneo. Extrapolating to 2008 on the basis of forest loss on both islands suggests the estimate for Borneo could be 10% too high but that for Sumatra is probably still relatively accurate because forest loss in orang-utan habitat has been low during the conflict in Aceh, where most P. abelii occur. When those population sizes are compared to known historical sizes it is clear that the Sumatran orang-utan is in rapid decline, and unless extraordinary efforts are made soon, it could become the first great ape species to go extinct. In contrast, our results indicate there are more and larger populations of Bornean orang-utans than previously known. Although these revised estimates for Borneo are encouraging, forest loss and associated loss of orang-utans are occurring at an alarming rate, and suggest that recent reductions of Bornean orang-utan populations have been far more severe than previously supposed. Nevertheless, although orang-utans on both islands are under threat, we highlight some reasons for cautious optimism for their long-term conservation.
Field experiments were conducted in Alabama during 1999 and 2000 to test the hypothesis that any glyphosate-induced yield suppression in glyphosate-resistant cotton would be less with irrigation than without irrigation. Yield compensation was monitored by observing alterations in plant growth and fruiting patterns. Glyphosate treatments included a nontreated control, 1.12 kg ai/ha applied POST at the 4-leaf stage, 1.12 kg/ha applied DIR at the prebloom stage, and 1.12 kg/ha applied POST at 4-leaf and postemergence directed (DIR) at the prebloom cotton stages. The second variable, irrigation treatment, was established by irrigating plots individually with overhead sprinklers or maintaining them under dryland, nonirrigated conditions. Cotton yield and all measured parameters including lint quality were positively affected by irrigation. Irrigation increased yield 52% compared to nonirrigated cotton. Yield and fiber quality effects were independent of glyphosate treatments. Neither yield nor any of the measured variables that reflected whole plant response were influenced by glyphosate treatment or by a glyphosate by irrigation interaction.
Ira Aldridge -- a black New Yorker -- was one of nineteenth-century Europe's greatest actors. He performed abroad for forty-three years, winning more awards, honors, and official decorations than any of his professional peers. Billed as the "African Roscius," Aldridge developed a repertoire initially consisting of Shakespeare's Othello, melodramas about slavery, and farces that drew on his ability to sing and dance. By the time he began touring in Europe he was principally a Shakespearean actor, playing such classic characters as Shylock, Macbeth, Richard III, and King Lear. Although his frequent public appearances made him the most visible black man in the world by mid-nineteenth century, today Aldridge tends to be a forgotten figure, seldom mentioned in histories of British and European theater. This collection restores the luster to Aldridge's reputation by examining his extraordinary achievements against all odds. The early essays offer biographical information, while later essays examine his critical and popular reception throughout the world. Taken together, these diverse approaches to Aldridge offer a fuller understanding and heightened appreciation of a remarkable man who had an exceptionally interesting life and a spectacular career. Contributors: Cyril Bruyn Andrews, Nikola Batusic, Philip A. Bell, Keith Byerman, Ruth M. Cowhig, Nicholas M. Evans, Joost Groeneboer, Ann Marie Koller, Joyce Green MacDonald, Herbert Marshall, James J. Napier, Krzysztof Sawala, Gunner Sjögren, James McCune Smith, Hazel Waters, and Stanley B. Winters.
Bernth Lindfors is Professor Emeritus of English and African literatures at The University of Texas at Austin.