Comparison of pQCT parameters between ulna and radius in retired elite gymnasts : the skeletal benefits associated with long-term gymnastics are bone- and site-specific

Objectives: To compare the skeletal benefits associated with gymnastics between ulna and radius.
Methods: 19 retired artistic gymnasts, aged 18-36 years, were compared to 24 sedentary women. Bone mineral content (BMC), total and cortical bone area (ToA, CoA), trabecular and cortical volumetric density (TrD, CoD) and cortical thickness (CoTh) were measured by pQCT at the 4% and 66% forearm.
Results: At the 4% site, BMC and ToA were more than twice greater at the radius than ulna whereas at the 66% site, BMC, ToA, CoA, CoTh and SSIpol were 20 to 51% greater at the ulna than radius in both groups (p<0.0001). At the 4% site, the skeletal benefits in BMC of the retired gymnasts over the non-gymnasts were 1.9 times greater at the radius than ulna (p<0.001), with enlarged bone size at the distal radius only. In contrast, the skeletal benefits at the 66% site were twice greater at the ulna than radius for BMC and CoA (p<0.01).
Conclusion: Whereas the skeletal benefits associated with long-term gymnastics were greater at the radius than ulna in the distal forearm, the reverse was found in the proximal forearm, suggesting both bones should be analysed when investigating forearm strength.

Students' use of online academic resources within a course web site and its relationship with their course performance : an exploratory study

Prior research suggests that the online provision of course materials can have a positive impact on students' examination performance. This study adds to the existing literature by investigating the link between the students' use of different forms of online course provisions and tools (i.e. course materials, links and discussion forums) and the final examination performance of students in a second year undergraduate accounting course. Findings indicate a positive association between the number of online files viewed by students, the number of online discussion messages posted by them, and their examination performance. A significant relationship was not found between examination performance and the amount of time spent on the subject's web site, the viewing of links to web sites that were not core to the course being studied, or the passive reading of discussion messages. These findings support the benefits to be gained by providing course materials online and encouraging students to access the materials posted and to participate actively in online discussion.

Design earthquake ground motion prediction for Perth metropolitan area with microtremor measurements for site characterization

Perth is the largest city in Western Australia and home to three-quarters of the state's residents. In recent decades, there have been a lot of earthquake activities just east of Perth in an area known as the South-West Seismic Zone. Previous numerical results of site response analyses based on limited available geology information for PMA indicated that Perth Basin might amplify the bedrock motion by more than 10 times at some frequencies and at some sites. Hence, more detailed studies on site characterization and amplification are necessary. The microtremor method using spatial autocorrelation (SPAC) processing is a useful tool for gaining thickness and shear wave velocity (SWV) of sediments and has been adopted in many previous studies. In this study, the response spectrum of rock site corresponding to the 475-year return period for PMA is defined according to the probabilistic seismic hazard analysis (PSHA) based on the latest ground motion attenuation model of Southwest Western Australia. Site characterization in PMA is performed using two microtremor measurements, namely SPAC technique and H/V method. The clonal selection algorithm (CSA) is introduced to perform direct inversion of SPAC curves to determine the soil profiles of representative PMA sites investigated in this study. Using the simulated bedrock motion as input, the responses of the soil sites are estimated using numerical method based on the shear-wave velocity vs. depth profiles determined from the SPAC technique. The response spectrum of the earthquake ground motion on surface of each site is derived from the numerical results of the site response analysis, and compared with the respective design spectrum defined in the Australian Earthquake Loading Code. The comparison shows that the code spectra are conservative in the short period range, but may slightly underestimate the response spectrum at some long period range.

From site to text : Australian Aborigines and the origin of the family

Missions were not simply sites of modernity, they were also the source of key data for the modernist theories of human progress. The idea that so called “primitive peoples” provided a window to the origins of human institutions seemed axiomatic to nineteenth-century theorists of human society who sought evidence for these ideas from settlers, administrators and particularly missionaries. The 1870s and 1880s were the high point of missionary engagement with study-bound anthropologists, as questionnaires and letters were sent from the centres to the edges of empires. Missionary responses, augmented with settler and explorer observations, became the footnotes in early anthropological texts on “primitive” societies. These analyses were then mined for the foundation texts of the other social sciences in the late nineteenth century. Along with many other scholars, Karl Marx and Friedrich Engels read the anthropology of the period and slotted the findings into their analyses of human society.

Factors affecting the site of investment, and the reliance on savings for arctic breeders : the capital–income dichotomy revisited

The extent to which migratory birds that breed in the Arctic and winter in southern biomes rely on residual body stores for reproduction is unresolved. The short arctic summer and the limited availability of food early in the season constrain the time available for successful reproduction. Birds that are able to bring sufficient endogenous reserves to the breeding ground to meet, at least partially, the demands of egg-laying can initiate clutch production soon after arrival, thereby shortening the length of the breeding season and improving the chances of reproductive success. The amount of reserves available will be influenced by body size, the increased energetic and predation costs associated with carrying large stores, distances between staging sites and the location of the breeding grounds within the Arctic. Birds need not fly directly to the breeding grounds from the established temperate staging sites. Extensive feeding by migrants may occur in the Arctic, even within a few kilometres of the breeding sites as the birds track the retreating snowline. Irrespective of their size, birds are thus able to store some resources necessary for egg laying at local or regional scales. It is thus important to make a distinction between local capital and distant capital breeding. The extent to which a bird is characterized as a distant capital, local capital, or an income breeder not only varies between species, but also between individuals and seasons.

Unbearable pressures on paradise? : Tourism and heritage management in Luang Prabang, a world heritage site

This article critically appraises and evaluates tourism strategies and heritage management in Luang Prabang, Lao People’s Democratic Republic, a Unesco-designated ‘world heritage’ city. Luang Prabang is widely regarded as one of the most significant heritage cities in Southeast Asia. The city is renowned for its Buddhist and royal culture and also its historic vernacular Lao, French, and Lao-French architecture. The city earned world heritage status in 1995, but since that time the boom in in-bound Asian tourism has put pressures on Luang Prabang’s authenticity and, for some, called into question the validity of its world heritage status. This article examines these substantial and wide-ranging pressures and argues that the growth in tourism and the treatment of Luang Prabang’s heritage are symptoms of broader regional processes of political and economic change, including the expansion of Chinese and Korean investments and the growth of intra-regional tourism. The authors argue that it is unreasonable to expect traditional heritage management mechanisims, including the world heritage listing, to be able to cope with the pressures on sites like Luang Prabang. The very least that is required, the authors contend, is an expanded understanding of the context in which heritage places sit, and the authors make a case that the cultural landscapes approach, combined with explicit concerns for intangible heritage and poverty alleviation, must be at the core of any strategy for long-term protection of the city’s cultural values.

Suburb as site : virtual collaborative learning for undergraduate photography

This paper describes a learning and teaching approach implemented in an undergraduate photography unit that is designed around a virtual collaborative experience. The approach was adopted several years ago and the process of continually refining the approach to enhance the student experience is outlined as are the benefits and challenges that have been encountered to date. The primary aim of the learning and teaching approach is to allow students to develop graduate attributes and technical skills that will prepare them to work in a contemporary media context – working in the virtual so as to understand approaches to developing and presenting work in the modern photography workplace. The approach also aims to engage and support students in a self reflective process where they examine the self and others focusing on aspects of contemporary culture and lifestyle, architecture and concepts of the home. Central to the approach is a virtual collaborative project where students are matched with partners to develop and present a cohesive virtual photography portfolio that contrasts their local environment: Suburb as Site. Finally, the paper describes the research project that is underway to enhance the collaboration matching process and evaluate the student experience. The research aims to contribute to improved staff understanding of the student experience with a view to further enhancing the learning and teaching approach.

Abandoned cubby huts: a site of dreaming and decay

The Cubby Hut is a powerful symbolic structure, an archetypal structure, and a place of imagination, dreams, refuge and adventure. The Cubby is ephemeral and passes from our childhood exploration of the world and into the dreams and memories of adulthood. These cubby huts are primarily built from and located in the landscape and are intrinsically linked to this context; they are landscape as architecture and architecture as landscape and in construction they articulate a connection between the imagination and landscape and decay as they return to the land and the psyche.

Changes in zinc ligation promote remodeling of the active site in the zinc hydrolase superfamily

The zinc hydrolase superfamily is a group of divergently related proteins that are predominantly enzymes with a zinc-based catalytic mechanism. The common structural scaffold of the superfamily consists of an eight-stranded β-sheet flanked by six α-helices. Previous analyses, while acknowledging the likely divergent origins of leucine aminopeptidase, carboxypeptidase A and the co-catalytic enzymes of the metallopeptidase H clan based on their structural scaffolds, have failed to find any homology between the active sites in leucine aminopeptidase and the metallopeptidase H clan enzymes. Here we show that these two groups of co-catalytic enzymes have overlapping dizinc centers where one of the two zinc atoms is conserved in each group. Carboxypeptidase A and leucine aminopeptidase, on the other hand, no longer share any homologous zinc-binding sites. At least three catalytic zinc-binding sites have existed in the structural scaffold over the period of history defined by available structures. Comparison of enzyme-inhibitor complexes show that major remodeling of the substrate-binding site has occurred in association with each change in zinc ligation in the binding site. These changes involve re-registration and re-orientation of the substrate. Some residues important to the catalytic mechanism are not conserved amongst members. We discuss how molecules acting in trans may have facilitated the mutation of catalytically important residues in the active site in this group.

Novel B-site ordered double perovskite Ba2Bi0.1Sc0.2Co1.7O6-x for highly efficient oxygen reduction reaction

Double perovskite Ba₂Bi_0.1Sc_0.2Co_1.7O_6-x (BBSC) demonstrates low polarization resistance between 600 and 750 °C due to the high oxygen reduction rate of BBSC as reflected by its large D_V and k values, which are derived from the face centered cubic structure and high cobalt content.