Effects of solute concentrations on kinetic pathways in Ni-Al-Cr alloys

The kinetic pathways resulting from the formation of coherent L12-ordered y'-precipitates in the g-matrix (f.c.c.) of Ni-7.5 Al-8.5 Cr at.% and Ni-5.2 Al-14.2 Cr at.% alloys, aged at 873 K, are investigated by atom-probe tomography (APT) over a range of aging times from 1/6 to 1024 hours; these alloys have approximately the same volume fraction of the y'-precipitate phase. Quantification of the phase decomposition within the framework of classical nucleation theory reveals that the y-matrix solid-solution solute supersaturations of both alloys provide the chemical driving force, which acts as the primary determinant of the nucleation behavior. In the coarsening regime, the temporal evolution of the y'-precipitate average radii and the y-matrix supersaturations follow the predictions of classical coarsening models, while the temporal evolution of the y'-precipitate number densities of both alloys do not. APT results are compared to equilibrium calculations of the pertinent solvus lines determined by employing both Thermo-Calc and Grand-Canonical Monte Carlo simulation.Comment: Submitted to Acta Materialia, June, 200

Satellite cell proliferation in adult skeletal muscle

Novel methods of retroviral-mediated gene transfer for the in vivo corporation and stable expression of eukaryotic or prokaryotic foreign genes in tissues of living animals is described. More specifically, methods of incorporating foreign genes into mitotically active cells are disclosed. The constitutive and stable expression of E. coli .beta.-galactosidase gene under the promoter control of the Moloney murine leukemia virus long terminal repeat is employed as a particularly preferred embodiment, by way of example, establishes the model upon which the incorporation of a foreign gene into a mitotically-active living eukaryotic tissue is based. Use of the described methods in therapeutic treatments for genetic diseases, such as those muscular degenerative diseases, is also presented. In muscle tissue, the described processes result in genetically-altered satellite cells which proliferate daughter myoblasts which preferentially fuse to form a single undamaged muscle fiber replacing damaged muscle tissue in a treated animal. The retroviral vector, by way of example, includes a dystrophin gene construct for use in treating muscular dystrophy. The present invention also comprises an experimental model utilizable in the study of the physiological regulation of skeletal muscle gene expression in intact animals

Entrepreneurship in island contexts: a systematic review of the tourism and hospitality literature

Entrepreneurship is vital to the success of tourism and hospitality and the sector makes an important contribution to many island economies. Despite this, far too little attention has been paid by researchers to tourism and hospitality entrepreneurship in islands (THEI). This research helps to address this gap through a systematic review of the literature, conducted to provide a platform for further research and to help investigators set their research priorities and thereby advance understanding of this important field. Using the Scopus database and the PRISMA technique, a total of 132 articles were included in bibliometric and thematic content analyses. The review revealed that, although there has been an increase in THEI research, this has tended to focus on the Asia-Pacific region rather than the European and North American contexts. It was also found that, hitherto, the generalizability of much THEI published research is limited. It is therefore suggested that researchers consider redressing this geographical bias and conduct more quantitative and comparative THEI studies. Further opportunities exist for scholars to investigate the characteristics and behaviors of tourism and hospitality island entrepreneurs as well as the impacts of the industrial and spatial aspects of THEI. For professionals working in island economic development and business support, this research identifies many of the challenges and opportunities associated with supporting THEI

ALMA 1.3 Millimeter Map of the HD 95086 System

Planets and minor bodies such as asteroids, Kuiper-belt objects and comets are integral components of a planetary system. Interactions among them leave clues about the formation process of a planetary system. The signature of such interactions is most prominent through observations of its debris disk at millimeter wavelengths where emission is dominated by the population of large grains that stay close to their parent bodies. Here we present ALMA 1.3 mm observations of HD 95086, a young early-type star that hosts a directly imaged giant planet b and a massive debris disk with both asteroid- and Kuiper-belt analogs. The location of the Kuiper-belt analog is resolved for the first time. The system can be depicted as a broad ($\Delta R/R \sim$0.84), inclined (30\arcdeg$\pm$3\arcdeg) ring with millimeter emission peaked at 200$\pm$6 au from the star. The 1.3 mm disk emission is consistent with a broad disk with sharp boundaries from 106$\pm$6 to 320$\pm$20 au with a surface density distribution described by a power law with an index of --0.5$\pm$0.2. Our deep ALMA map also reveals a bright source located near the edge of the ring, whose brightness at 1.3 mm and potential spectral energy distribution are consistent with it being a luminous star-forming galaxy at high redshift. We set constraints on the orbital properties of planet b assuming co-planarity with the observed disk.Comment: accepted for publication in A

Semileptonic Decays: an Update Down Under

Heavy-meson semileptonic decays calculations on the lattice are reviewed. The focus is upon obtaining reliable matrix elements. Errors that depend upon the lattice spacing, $a$, are an important source of systematic error. Full $O(a)$ improvement of matrix elements for arbitrary-mass four-component quarks is discussed. With improvement, bottom-quark matrix elements can be calculated directly using current lattices. Momentum dependent errors for $O(a)$-improved quarks and statistical noise limit momenta to around 1 GeV/c with current lattices. Hence, maximum recoil momenta can be reached for $D$ decays while only a fraction of the maximum recoil momentum can be reliably studied for the light-meson decay modes of the $B$. Differential decay rates and partial widths are phenomenologically important quantities in $B$ decays that can be reliably determined with present lattices.Comment: 14 pages, 9 postscript figures, requires espcrc2.st

Fire Frequency and Time-Since-Fire Effects on the Open-Forest and Woodland Flora of Girraween National Park, South-East Queensland

The effect of recent fire frequency and time-since-fire on plant community composition and species abundance in open-forest and woodland vegetation in Girraween National Park, south-east Queensland, were examined. Cover-abundance data were collected for shrub and vine species in at least ten 400 m2 plots in each of four study areas. Study areas were within one community type and had burnt most recently either four or nine years previously. Variations in fire frequency allowed us to compare areas which had burnt at least three times in the last 25 years with less frequently burnt areas, and also woodlands which experienced a 28-year interfire interval with more frequently burnt areas. While species richness did not differ significantly with either time-since-fire or fire frequency, both these factors affected community composition, fire frequency being the more powerful. Moisture availability also influenced floristics. Of the 67 species found in five or more plots, six were significantly associated with time-since-fire, while 11 showed a significant difference between more and less frequently burnt plots on each of the two fire frequency variables. Most species, however, did not vary in cover-abundance with the fire regime parameters examined. Even those species that showed a marked drop in cover-abundance when exposed to a particular fire regime generally maintained some presence in the community. Six species with the capacity to resprout after fire were considered potentially at risk of local extinction under regimes of frequent fire, while two species were relatively uncommon in long-unburnt areas. Variable fire regimes, which include interfire intervals of at least 15 years, may be necessary for the continuity of all species in the community

Museum tourism 2.0: experiences and satisfaction with shopping at the National Gallery in London

The tourist shopping experience is the sum of the satisfaction or dissatisfaction from the individual attributes of purchased products and services. With the popularity of the Internet and travel review websites, more people choose to upload their tour experiences on their favorite social media platforms, which can influence another’s travel planning and choices. However, there have been few investigations of social media reviews of tourist shopping experiences and especially of satisfaction with museum tourism shopping. This research analyzed the user-generated reviews of the National Gallery (NG) in London written in the English language on TripAdvisor to learn more about tourist shopping experience in museums. The Latent Dirichlet Allocation (LDA) topic model was used to discover the underlying themes of online reviews and keywords related to these shopping experiences. Sentiment analysis based on a purpose-developed dictionary was conducted to explore the dissatisfying aspects of tourist shopping experiences. The results provide a framework for museums to improve shopping experiences and enhance their future development

Innovative or Not? The Effects of Consumer Perceived Value on Purchase Intentions for the Palace Museum’s Cultural and Creative Products

A museum’s core activities traditionally focus on such areas as collections’ care, exhibitions and scholarship. Income generation, including retail activities, is considered secondary. Academic research into museums’ merchandise, especially into the perceived value and purchase intentions, is limited. Drawing on literature embracing both core museum functions and marketing, this research, based on the Palace Museum in Beijing, China, explores the impact of the perceived value of a museum’s cultural and creative products on purchase intentions. Combining the results of in-depth interviews with museum visitors and experts, this study defines a construct composed of six perceived value dimensions, namely quality, social, price, innovation, educational, and experience values. A relationship model of perceived value and purchase intentions is proposed. Some 346 valid survey responses were obtained by distributing a questionnaire online and on-site at the Palace Museum, and hypotheses were tested by structural equation modelling. Results showed that innovation and experience values have a significant positive effect on purchase intentions, while quality, social, price, and educational values had no significant influence on purchase intentions. This research outlines feasible strategies and actions for the development of cultural and creative products at museums that have a strong tourism role

Profit sharing, separation and training

Theory presents two broad channels through which profit sharing can increase worker training. First, it directly increases training by alleviating hold-up problems and/or by encouraging co-workers to provide training. Second, it indirectly increases training by reducing worker separation and increasing training investments' amortization period. This article provides the first attempt at separately identifying these two channels. We confirm a strong direct effect, but also identify a weaker, more tenuous indirect effect. This suggests that profit sharing's influence on training is unlikely to operate primarily through its reduction on separations while simultaneously presenting the first evidence confirming the prediction of an indirect causation