UNLV Wind Orchestra

Program listing performers and works performed

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal–ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inversetrans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C¼M¼C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle

Conscientiousness, Career Success, and Longevity: A Lifespan Analysis

Markers of executive functioning, such as prudent planning for the future and impulse control, are related to conscientiousness and may be central to both occupational success and health outcomes. The aim of the study was to examine relations among conscientiousness, career success, and mortality risk across a 65-year period. Using data derived from 693 male participants in the Terman Life Cycle Study, we examined associations among childhood personality, midlife objective career success, and lifelong mortality risk through 2006. Conscientiousness and career success each predicted lower mortality risk (N = 693, relative hazard (rh) = 0.82 [95% confidence interval = 0.74, 0.91] and rh = 0.80 [0.71, 0.91], respectively), with both shared and unique variance. Importantly, childhood personality moderated the success–longevity link; conscientiousness was most relevant for least successful individuals. Conscientiousness and career success predicted longevity, but not in a straightforward manner. Findings highlight the importance of lifespan processes

Robustness of Learning That Is Based on Covariance-Driven Synaptic Plasticity

It is widely believed that learning is due, at least in part, to long-lasting modifications of the strengths of synapses in the brain. Theoretical studies have shown that a family of synaptic plasticity rules, in which synaptic changes are driven by covariance, is particularly useful for many forms of learning, including associative memory, gradient estimation, and operant conditioning. Covariance-based plasticity is inherently sensitive. Even a slight mistuning of the parameters of a covariance-based plasticity rule is likely to result in substantial changes in synaptic efficacies. Therefore, the biological relevance of covariance-based plasticity models is questionable. Here, we study the effects of mistuning parameters of the plasticity rule in a decision making model in which synaptic plasticity is driven by the covariance of reward and neural activity. An exact covariance plasticity rule yields Herrnstein's matching law. We show that although the effect of slight mistuning of the plasticity rule on the synaptic efficacies is large, the behavioral effect is small. Thus, matching behavior is robust to mistuning of the parameters of the covariance-based plasticity rule. Furthermore, the mistuned covariance rule results in undermatching, which is consistent with experimentally observed behavior. These results substantiate the hypothesis that approximate covariance-based synaptic plasticity underlies operant conditioning. However, we show that the mistuning of the mean subtraction makes behavior sensitive to the mistuning of the properties of the decision making network. Thus, there is a tradeoff between the robustness of matching behavior to changes in the plasticity rule and its robustness to changes in the properties of the decision making network

Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity

Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria

Ten years of Ana: lessons from a transdisciplinary body of literature on online pro-eating disorder websites

This paper offers a methodical review of the scientific literature of the last decade that concerns itself with online services offering supportive advocacy for anorexia nervosa and bulimia nervosa (‘pro-ana’ and ‘pro-mia’). The main question is whether these studies reproduce the traditional divide in the study of eating disorders, between clinical and social science perspectives, with limited mutual exchanges. Having first identified a specific body of literature, the authors investigate its content, methods and approaches, and analyse the network of cross-citations the components generate and share. On this basis, the authors argue that the scientific literature touching on pro-ana websites can be regarded as a single transdisciplinary body of knowledge. What’s more, they show that the literature on computermediated sociabilities centred on eating disorders displays different structural characteristics with respect to the traditional, non-Web-related research on eating disorders. In the latter, the social sciences have usually provided a critical counterpoint to the development of a health sciences mainstream. In the case of Web-related research, however, the social sciences have taken the lead role in defining the field, with the health sciences following suit

Ascending central canal dilation and progressive ependymal disruption in a contusion model of rodent chronic spinal cord injury

<p>Abstract</p> <p>Background</p> <p>Chronic spinal cord injury (SCI) can lead to an insidious decline in motor and sensory function in individuals even years after the initial injury and is accompanied by a slow and progressive cytoarchitectural destruction. At present, no pathological mechanisms satisfactorily explain the ongoing degeneration.</p> <p>Methods</p> <p>Adult female Sprague-Dawley rats were anesthetized laminectomized at T10 and received spinal cord contusion injuries with a force of 250 kilodynes using an Infinite Horizon Impactor. Animals were randomly distributed into 5 groups and killed 1 (n = 4), 28 (n = 4), 120 (n = 4), 450 (n = 5), or 540 (n = 5) days after injury. Morphometric and immunohistochemical studies were then performed on 1 mm block sections, 6 mm cranial and 6 mm caudal to the lesion epicenter. The SPSS 11.5 t test was used to determine differences between quantitative measures.</p> <p>Results</p> <p>Here, we document the first report of an ascending central canal dilation and progressive ependymal disruption cranial to the epicenter of injury in a contusion model of chronic SCI, which was characterized by extensive dural fibrosis and intraparenchymal cystic cavitation. Expansion of the central canal lumen beyond a critical diameter corresponded with ependymal cell ciliary loss, an empirically predictable thinning of the ependymal region, and a decrease in cell proliferation in the ependymal region. Large, aneurysmal dilations of the central canal were accompanied by disruptions in the ependymal layer, periependymal edema and gliosis, and destruction of the adjacent neuropil.</p> <p>Conclusion</p> <p>Cells of the ependymal region play an important role in CSF homeostasis, cellular signaling and wound repair in the spinal cord. The possible effects of this ascending pathology on ependymal function are discussed. Our studies suggest central canal dilation and ependymal region disruption as steps in the pathogenesis of chronic SCI, identify central canal dilation as a marker of chronic SCI and provide novel targets for therapeutic intervention.</p