1,827 research outputs found

    Non-normal real estate return distributions by property type in the U.K.

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    Investment risk models with infinite variance provide a better description of distributions of individual property returns in the IPD database over the period 1981 to 2003 than Normally distributed risk models, which mirrors results in the U.S. and Australia using identical methodology. Real estate investment risk is heteroscedastic, but the Characteristic Exponent of the investment risk function is constant across time yet may vary by property type. Asset diversification is far less effective at reducing the impact of non-systematic investment risk on real estate portfolios than in the case of assets with Normally distributed investment risk. Multi-risk factor portfolio allocation models based on measures of investment codependence from finite-variance statistics are ineffectual in the real estate context

    Using cognitive work analysis to explore activity allocation within military domains

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    Cognitive Work Analysis (CWA) is frequently advocated as an approach for the analysis of complex sociotechnical systems. Much of the current CWA literature within the military domain pays particular attention to its initial phases; Work Domain Analysis and Contextual Task Analysis. Comparably, the analysis of the social and organisational constraints receives much less attention. Through the study of a helicopter Mission Planning System (MPS) software tool, this paper describes an approach for investigating the constraints affecting the distribution of work. The paper uses this model to evaluate the potential benefits of the social and organisational analysis phase within a military context. The analysis shows that, through its focus on constraints the approach provides a unique description of the factors influencing the social organisation within a complex domain. This approach appears to be compatible with existing approaches and serves as a validation of more established social analysis techniques

    The Transmembrane Domains of the EBV-Encoded Latent Membrane Protein 1 (LMP1) Variant CAO Regulate Enhanced Signalling Activity

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    AbstractSequence variants of the Epstein–Barr virus (EBV)-encoded latent membrane protein-1 (LMP1) have been reported in association with EBV-linked malignancies but little is known about their effects on signalling pathways and phenotype. We have examined the ability of the nasopharyngeal carcinoma (NPC)-derived variant, CAO-LMP1 to activate the transcription factors NF-ÎșB and AP-1 in epithelial cells. In this study, transient expression of CAO-LMP1 was found to activate higher levels of NF-ÎșB and AP-1 than the prototype B95.8-LMP1 in human embryonic kidney (HEK) 293 cells and SV40-transformed keratinocytes (SVK). In addition, pulse–chase analysis revealed that CAO-LMP1 has a longer half-life than B95.8-LMP1. Chimera studies localised these phenomena to the transmembrane domains of CAO-LMP1, suggesting that this enhanced signalling capacity may be a consequence of its prolonged half-life. The ability of CAO-LMP1 to activate higher levels of NF-ÎșB and AP-1 may contribute to its potent transforming properties

    Chern-Simons Reduction and non-Abelian Fluid Mechanics

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    We propose a non-Abelian generalization of the Clebsch parameterization for a vector in three dimensions. The construction is based on a group-theoretical reduction of the Chern-Simons form on a symmetric space. The formalism is then used to give a canonical (symplectic) discussion of non-Abelian fluid mechanics, analogous to the way the Abelian Clebsch parameterization allows a canonical description of conventional fluid mechanics.Comment: 12 pages, REVTeX; revised for publication in Phys Rev D; email to [email protected]

    In vitro discrimination of wound-associated bacteria by volatile compound profiling using selected ion flow tube-mass spectrometry

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    © 2017 The Society for Applied Microbiology Aims: To determine if bacterial species responsible for clinically relevant wound infection produce specific volatile profiles that would allow their speciation. Methods and Results: Selected ion flow tube-mass spectrometry (SIFT-MS) in full mass scan mode was used to analyse headspace gases produced by wound-associated bacteria grown invitro, so as to enable identification of bacterial volatile product ion profiles in the resulting mass spectra. Applying multivariate statistical analysis (hierarchical clustering and principal component analysis) to the resultant mass spectra enabled clear speciation. Moreover, bacterial volatile product ions could be detected from artificially contaminated wound dressing material, although the pattern of product ions detected was influenced by culture conditions. Conclusions: Using selected product ions from the SIFT-MS mass spectra it is possible to discriminate wound-associated bacterial species grown under specific invitro culture conditions. Significance and Impact of the Study: The results of this study have shown that wound-associated bacteria can be discriminated using volatile analysis invitro and that bacterial volatiles can be detected from wound dressing material. This indicates that volatile analysis of wounds or dressing material to identify infecting microbes has potential and warrants further study

    Talent development environment and achievement goal adoption among Korean and Singaporean athletes: Does perceived competence matter?

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    The objectives of this study were twofold. The first was to compare differences in perceptions of the talent development environment, achievement goals, and perceived competence, in terms of an individual characteristic (i.e., gender), a cultural characteristic (i.e., country), and their interactions (i.e., gender by country). The second was to examine the moderating effects of perceived competence on the relationships between the talent development environment and achievement goals. Data were collected from 363 athletes in Singapore and 349 athletes in Korea. A series of MANOVAs and path analyses were employed for testing of the main hypotheses. First, in terms of the talent development environment, male athletes scored higher in long term development focus, communication, support network, and long term development fundamentals. Second, in terms of achievement goals and perceived competence, male athletes scored higher in competence and performance-approach goal, but female athletes scored higher in mastery-avoidance goal. While Singaporean athletes scored higher in perceived competence, mastery-approach and mastery-avoidance, Korean athletes scored higher in performance-avoidance. Lastly, the path analysis provided empirical evidence supporting the moderation effects of perceived competence on the relationships between the talent development environment and achievement goal adoption

    Blood Pressure Control for African American Parents and Children: Feasibility and Initial Outcomes of a Faith-based Intervention Pilot Study

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    The overall purpose was to determine the feasibility and initial outcomes of a faith-based intervention to improve blood pressure (BP) control in African American (AA) parents/guardians and their children, using a pre/post without control group design. Sample included AA parents and children (n=17) from three churches in North Florida. Health behaviors (daily servings of fruits/vegetables [F/V], minutes of physical activity [PA]) and physical health (BMI, systolic BP and diastolic SB) were examined. Data were analyzed using descriptive statistics, paired t-tests, and correlations. Feasibility outcomes showed high attendance (91% children, 88% parents) and completion (100%) rates. F/V significantly increased at post-test in adults (p=.02) and approached significance in children (p=.07). Positive trends at post-test were noted in PA, BMI, SBP and DBP in both groups. There were significant correlations at post-test for F/V (p=.01) and SBP (p=.006) for the parent/child dyads. Findings suggest that the intervention was feasible and has promise to improve health outcomes

    Evidence for internal field in graphite: A conduction electron spin resonance study

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    We report conduction electron spin resonance measurements performed on highly oriented pyrolitic graphite samples between 10 K and 300 K using S (f = 4 GHz), X (f = 9.4 GHz), and Q (f = 34.4 GHz) microwave bands for the external dc-magnetic field applied parallel (H || c) and perpendicular (H perp c) to the sample hexagonal c-axis. The results obtained in the H || c geometry are interpreted in terms of the presence of an effective internal ferromagnetic-like field Heff-int(T,H) that increases as the temperature decreases and the applied dc-magnetic field increases. We associate the occurrence of the Heff-int(T,H) with the field-induced metal-insulator transition in graphite and discuss its origin in the light of relevant theoretical models.Comment: 10 pages (tex), 5 figures (ps

    Rhizobacterial influence on healthy stand establishment of canola grown in Rhizoctonia solani infested fields of Saskatchewan

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    Non-Peer ReviewedPre-emergence seedling damping-off, seedling blight, and brown girdling root rot caused by R. solani are important diseases of canola/rape seed in western Canada. Annual yield losses in excess of 20-30% have been reported in several infected fields. Cultural control methods or resistant cultivars are currently unavailable for these diseases. Chemical fungicides have been developed for use to control the disease, but the success rate has been varied. However, the use of chemicals is becoming less acceptable from an environmental point of view. Several studies indicated that biological control using plant growth promoting rhizobacteria may also be effective in controlling R. solani. Field plots were established in Saskatoon, Regina and Melfort, SK, in 1990, 1991 and 1992 to evaluate the potential of rhizobacterial strains as seed treatments to increase the healthy stand of canola CV. Westar grown in R. solani infested field. The bacteria were formulated either in sterile peat or in a liquid carrier and applied to seed just before planting. Bacterized seed were mechanically planted in replicated field plots artificially infested with R. solani. Final healthy stand was measured 30 days after planting. Grain yields were determined by harvesting the plots. Seed bacterization significantly increased the final healthy stand compared to non-bacterized controls. Strains which increased stand showed in vitro antagonistic activity to not only R. solani but also other pathogens such as Pythium ultimum, Fusarium solani and F. oxysporum. Some of these strains induced root elongation of canola under laboratory conditions. Rhizosphere colonization, chemical compatibility and shelf-life of the important bacteria will be discussed

    Kinetics and Mechanism of Hydroxyapatite Crystal Dissolution in Weak Acid Buffers Using the Rotating Disk Method

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    The dissolution rates of synthetic hydroxyapatite pellets under sink conditions were measured using the rotating disk method. The experimental data were analyzed by means of a physical model that yielded an ionic activity product of KHAP = a10Ca2+ a6 PO4 3- a2OH- = 1 × 10-124.5±1.0 that was found to govern the dissolution reaction. Also, a surface resistance factor of k' equal to about 174 sec/cm was deduced from the data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67157/2/10.1177_00220345760550033201.pd
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