Comparative analysis of the seismic hazard of Central China

Seismic hazard assessment is globally recognised as a tool in identifying levels of earthquake ground shaking within an area. However, methodologies for seismic hazard calculation are wide ranging and produce variations in results and maps. As a case study seismic hazard and results from Gumbel’s method of extremes are determined for the area of greatest intraplate seismicity in China covering the provinces of Gansu, Sichuan and Yunnan. This area is termed the North-South Seismic Zone. Devastating earthquakes in this zone include the 8.4 MS 1920 Haiyuan earthquake causing over 220,000 deaths and the 1996 Lijiang earthquake. Most recently the 2008 Wenchuan earthquake caused over 69,000 deaths with more than 18,000 people missing. These results and seismic hazard maps are compared with the publicly available maps of GSHAP and the national seismic hazard map of China at the level of 10% probability of exceedance in a 50 year period. The distributions of high and low hazard areas are similar and adjacent to the major thrust and strike-slip faults dominating in this area. However, results from the Gumbel method of extremes suggest that the hazard levels within certain areas are slightly different compared to the other two models. This is primarily because the Gumbel methodology is based on determining hazard from earthquakes that have already taken place whereas the other two models determine maximum hazard levels in areas which may exhibit no previous strong hazard. Additionally the Chinese national hazard map does not indicate levels of ground shaking intensity greater than IX in detail, whereas such zones are identified using the extreme value method. This work should be used to strengthen the seismic hazard analysis of this area of China

Optimal co-adapted coupling for a random walk on the hyper-complete-graph

The problem of constructing an optimal co-adapted coupling for a pair of symmetric random walks on $Z_2^d$ was considered by Connor and Jacka (2008), and the existence of a coupling which is stochastically fastest in the class of all such co-adapted couplings was demonstrated. In this paper we show how to generalise this construction to an optimal co-adapted coupling for the continuous-time symmetric random walk on $K_n^d$, where $K_n$ is the complete graph with $n$ vertices. Moreover, we show that although this coupling is not maximal for any $n$ (i.e. it does not achieve equality in the coupling inequality), it does tend to a maximal coupling as $n\to\infty$.Comment: 20 pages, 1 figur

Stern-Gerlach surfing in laser wakefield accelerators

We investigate the effects of a Stern-Gerlach-type addition to the Lorentz force on electrons in a laser wakefield accelerator. The Stern-Gerlach-type terms are found to generate a family of trajectories describing electrons that surf along the plasma density wave driven by a laser pulse. Such trajectories could lead to an increase in the size of an electron bunch, which may have implications for attempts to exploit such bunches in future free electron lasers

The implications of performance management for teacher professionalism

In the UK over the past twenty years, notions of teacher professionalism have shifted in response to a series of changes to teachers\u27 work processes wroughtby successive governments. Increasing emphasis on accountability, curriculum prescription and performance indicators has diminished teacher autonomy and eroded personal responsibility for professional development. It is argued in the paper that the current Performance management agenda legitimates this erosion through the rhetoric of raising standards

Seismic hazard and risk in Shanghai and estimation of expected building damage

The People's Republic of China is in the process of rapid demographic, economic and urban change including nationwide engineering and building construction at an unprecedented scale. The mega-city of Shanghai is at the centre of China's modernisation. Rapid urbanisation and building growth have increased the exposure of people and property to natural disasters. The seismic hazard of Shanghai and its vicinity is presented from a seismogenic free-zone methodology. A PGA value of 49 cm s-2 and a maximum intensity value of VII for the Chinese Seismic Intensity Scale (a scale similar to the Modified Mercalli) for a 99% probability of non-exceedance in 50 years are determined for Shanghai city. The potential building damage for three independent districts of the city centre named Putuo, Nanjing Road and Pudong are calculated using damage vulnerability matrices. It is found that old civil houses of brick and timber are the most vulnerable buildings with potentially a mean probability value of 7.4% of this building structure type exhibiting the highest damage grade at intensity VII

Power law relationships in the branches of loblolly pine, red maple and sugar maple trees

Abstract: Power laws are interesting patterns that exist over wide ranges. Power laws may be used to determine the organization of countless networks in nature. The purpose of this study was to test whether the distribution patterns in shoot lengths of three popular tree species follow a power law. This study not only adds to the general knowledge base for these species but also may be used to make predictions about other species. Three common tree species were included in this study: loblolly pine (Pinus taeda), red maple (Acer rubrum), and the sugar maple (Acer saccharum). The height and all shoot lengths of five individuals of each tree species were measured, recorded and sorted. Loblolly pines and sugar maples followed the same power law at individual and species level. Most of the red maple individuals did not follow a power law although they followed a power law at the species level. One possible reason might be that the red maple trees measured were too young and were in strong competition for resources with other tree species

Comparative aspects of the thermal biology of African and Australian parrots.

Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.Deserticolous birds inhabit an environment characterised by high ambient temperatures and low rainfall that has low primary productivity. The combination of these factors may lead to the evolution of adaptations that minimise food and water requirements. One physiological adaptation that has been found in many deserticolous birds is the reduction of basal metabolic rate (BMR). I measured metabolic rate in the laboratory using four species of African lovebirds (Agapornis) , and four species of Australian grass parakeets (one Neopsephotus and three Neophema), all similar in body mass. Tests for differences between groups were carried out using both conventional and phylogenetically independent methods. The BMRs of the lovebird and grass parakeet species were not statistically correlated with habitat type. These results confirm the findings of previous studies on the effect of desert conditions on the BMR of parrots. I also found no significant differences in BMR between the species assemblages from different continents. The lack of significant differences in BMR between deserticolous and nondeserticolous parrots supports the idea that birds are "ex-adapted" to living in desert environments. I suggest that the results may have been affected by phenotypic plasticity in BMR, as recent evidence has shown that the scaling exponent of BMR differs between captive-raised and wild-caught birds. To elucidate the effect of origin (captive-raised vs. wild-caught) on the BMR of birds used in this study a large scale analysis of bird BMR data was undertaken. BMR and body mass data for 242 species of birds were obtained from the literature, this study, and unpublished data from various sources. A phylogeny was constructed using molecular and morphological phylogenies from the literature, and analysed using conventional and phylogenetically independent methods. The conventional analysis found significant differences in the scaling exponents of BMR of captive-raised and wild-caught birds. However the phylogenetically independent method showed non-significant differences between these two groups. Conventional analysis of differences between parrots and all other birds yielded significant differences between these two groups, with parrots having significantly higher BMRs than other birds. Again the phylogenetically independent analysis found non-significant differences between these VII two groups. A test of homogeneity of variance between these two groups found significant differences between the variances ofthe two groups, probably due to disparity in sample size and range of body sizes. The conventional and phylogenetically independent tests for differences between captive-raised and wild-caught parrots yielded non-significant results, suggesting that the parrots are not subject to the phenotypic adjustments postulated for all other birds. The lack of significant differences between captive-raised and wild-caught parrots suggests that the analyses of differing habitat type for African and Australian parrots is indeed valid

Regulation of AKT phosphorylation at Ser473 and Thr308 by endoplasmic reticulum stress modulates substrate specificity in a severity dependent manner.

Endoplasmic reticulum (ER) stress is a common factor in the pathophysiology of diverse human diseases that are characterised by contrasting cellular behaviours, from proliferation in cancer to apoptosis in neurodegenerative disorders. Coincidently, dysregulation of AKT/PKB activity, which is the central regulator of cell growth, proliferation and survival, is often associated with the same diseases. Here, we demonstrate that ER stress modulates AKT substrate specificity in a severity-dependent manner, as shown by phospho-specific antibodies against known AKT targets. ER stress also reduces both total and phosphorylated AKT in a severity-dependent manner, without affecting activity of the upstream kinase PDK1. Normalisation to total AKT revealed that under ER stress phosphorylation of Thr308 is suppressed while that of Ser473 is increased. ER stress induces GRP78, and siRNA-mediated knock-down of GRP78 enhances phosphorylation at Ser473 by 3.6 fold, but not at Thr308. Substrate specificity is again altered. An in-situ proximity ligation assay revealed a physical interaction between GRP78 and AKT at the plasma membrane of cells following induction of ER stress. Staining was weak in cells with normal nuclear morphology but stronger in those displaying rounded, condensed nuclei. Co-immunoprecipitation of GRP78 and P-AKT(Ser473) confirmed the immuno-complex consists of non-phosphorylated AKT (Ser473 and Thr308). The interaction is likely specific as AKT did not bind to all molecular chaperones, and GRP78 did not bind to p70 S6 kinase. These findings provide one mechanistic explanation for how ER stress contributes to human pathologies demonstrating contrasting cell fates via modulation of AKT signalling