Effect of Axial Agitator Configuration (Up-Pumping, Down-Pumping, Reverse Rotation) on Flow Patterns Generated in Stirred Vessels

Single phase turbulent flow in a tank stirred with two different axial impellers - a pitched blade turbine (PBT) and a Mixel TT (MTT)- has been studied using Laser Doppler Velocimetry. The effect of the agitator configuration, i.e. up-pumping, down-pumping and reverse rotation, on the turbulent flow field, as well as power, circulation and pumping numbers has been investigated. An agitation index for each configuration was also determined. In the down-pumping mode, the impellers induced one circulation loop and the upper part of the tank was poorly mixed. When up-pumping, two circulation loops are formed, the second in the upper vessel. The PBT pumping upwards was observed to have a lower flow number and to consume more power than when down-pumping, however the agitation index and circulation efficiencies were notably higher. The MTT has been shown to circulate liquid more efficiently in the up-pumping configuration than in the other two modes. Only small effects of the MTT configuration on the power number, flow number and pumping effectiveness have been observed

A clinical note on an outbreak of cutaneous anthrax in the Lundi native reserve

A CAJM article on an outbreak of anthrax in a province of Southern Rhodesia (now Zimbabwe) in the 1950's.Twenty-two cases of cutaneous anthrax were admitted in January, 1954, to the Lundi Clinic in the Shabani district, and three further cases were seen shortly after. The first two cases were admitted with lesions on the hand and shoulder. These, most aptly covered by the term “ malignant pustule,” consisted of a small dark or black necrotic centre surrounded by a rim of vesicles and pustules, and beyond that a ring of cellulitis and oedema of varying extent. Constitutional symptoms were marked, the temperature rising to- 104° F. The lesion progressed characteristically to form a central, black, concave eschar up to 1 inch. in diameter, surrounded by a rim of vesicles and a decreasing area of cellulitis and oedema. Many cases were admitted in this stage, with only slight constitutional disturbance

Analysis of vehicle rollover dynamics using a high-fidelity model

Recent data show that 35% of fatal crashes in sport utility vehicles included vehicle rollover. At the same time, experimental testing to improve safety is expensive and dangerous. Therefore, multi-body simulation is used in this research to improve the understanding of rollover dynamics. The majority of previous work uses low-fidelity models. Here, a complex and highly nonlinear multi-body model with 165 degrees of freedom is correlated to vehicle kinematic and compliance (K&C) measurements. The Magic Formula tyre model is employed. Design of experiment methodology is used to identify tyre properties affecting vehicle rollover. A novel, statistical approach is used to link suspension K&C characteristics with rollover propensity. Research so far reveals that the tyre properties that have the greatest influence on vehicle rollover are friction coefficient, friction variation with load, camber stiffness and tyre vertical stiffness. Key K&C characteristics affecting rollover propensity are front and rear suspension rate, front roll stiffness, front camber gain, front and rear camber compliance and rear jacking force. © 2014 Taylor & Francis

Heart versus Head: Differential Bodily Feedback Causally Alters Economic Decision-making

Metaphorically, altruistic acts, such as monetary donations, are said to be driven by the heart, whereas sound financial investments are guided by reason, embodied by the head. In a unique experiment, we tested the effects of these bodily metaphors using biofeedback and an incentivized economic decision-making paradigm. Participants played a repeated investment game with a simulated partner, alternating between tactical investor and altruistic investee. When making decisions, participants received counterbalanced visual feedback from their own or a simulated partner’s heart or head, as well as no feedback. As investor, participants transferred a greater proportion of their endowments when exposed to visual feedback from their own head than to feedback from their own heart or no feedback at all. These effects were not observed when the source of the feedback was the simulated partner. As investee, heart feedback predicted greater altruistic returns than head or no feedback, but this effect did not differ based on source (own vs partner). Consistent with a dual-process framework, we suggest that people may be encouraged to invest more or be more altruistic when receiving bodily feedback from conceptually diametric sources

A spatial model of cognitive distance in cities

Spatial cognition is fundamental to the behaviour and activity of humans in urban space. Humans perceive their environments with systematic biases and errors, and act upon these perceptions, which in turn form urban patterns of activity. These perceptions are influenced by a multitude of factors, many of them relating to the static urban form. Yet much of geographic analysis ignores the influence of urban form, instead referring most commonly to the Euclidean arrangement of space. In this paper, we propose a novel spatial modelling framework for estimating cognitive distance in urban space. This framework is constructed from a wealth of research describing the effect of environmental factors on distance estimation, and produces a quantitative estimate of the effect based on standard GIS data. Unlike other cost measures, the cognitive distance estimate integrates systematically observed distortions and biases in spatial cognition. As a proof-of-concept, the framework is implemented for 26 cities worldwide using open data, producing a novel comparative measure of ‘cognitive accessibility’. The paper concludes with a discussion of the potential of this approach in analysing and modelling urban systems, and outlines areas for further research

Spirit: Multifunctional Framework for Atomistic Spin Simulations

The \textit{Spirit} framework is designed for atomic scale spin simulations of magnetic systems of arbitrary geometry and magnetic structure, providing a graphical user interface with powerful visualizations and an easy to use scripting interface. An extended Heisenberg type spin-lattice Hamiltonian including competing exchange interactions between neighbors at arbitrary distance, higher-order exchange, Dzyaloshinskii-Moriya and dipole-dipole interactions is used to describe the energetics of a system of classical spins localised at atom positions. A variety of common simulations methods are implemented including Monte Carlo and various time evolution algorithms based on the Landau-Lifshitz-Gilbert equation of motion, which can be used to determine static ground state and metastable spin configurations, sample equilibrium and finite temperature thermodynamical properties of magnetic materials and nanostructures or calculate dynamical trajectories including spin torques induced by stochastic temperature or electric current. Methods for finding the mechanism and rate of thermally assisted transitions include the geodesic nudged elastic band method, which can be applied when both initial and final states are specified, and the minimum mode following method when only the initial state is given. The lifetime of magnetic states and rate of transitions can be evaluated within the harmonic approximation of transition-state theory. The framework offers performant CPU and GPU parallelizations. All methods are verified and applications to several systems, such as vortices, domain walls, skyrmions and bobbers are described

Involvement of TSC genes and differential expression of other members of the mTOR signaling pathway in oral squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Despite extensive research, the five-year survival rate of oral squamous cell carcinoma (OSCC) patients has not improved. Effective treatment of OSCC requires the identification of molecular targets and signaling pathways to design appropriate therapeutic strategies. Several genes from the mTOR signaling pathway are known to be dysregulated in a wide spectrum of cancers. However, not much is known about the involvement of this pathway in tumorigenesis of OSCC. We therefore investigated the role of the tumor suppressor genes, <it>TSC1 </it>and <it>TSC2</it>, and other members of this pathway in tumorigenesis of OSCC.</p> <p>Methods</p> <p>Expression of genes at the RNA and protein levels was examined by semi-quantitative RT-PCR and western blot analyses, respectively. Loss of heterozygosity was studied using matched blood and tumor DNA samples and microsatellite markers from the <it>TSC1</it>, <it>TSC2 </it>and <it>PTEN </it>candidate regions. The effect of promoter methylation on TSC gene expression was studied by treating cells with methyltransferase inhibitor 5-azacytidine. Methylation status of the <it>TSC2 </it>promoter in tissue samples was examined by combined bisulfite restriction analysis (COBRA).</p> <p>Results</p> <p>The semi-quantitative RT-PCR analysis showed downregulation of <it>TSC1</it>, <it>TSC2</it>, <it>EIF4EBP1 </it>and <it>PTEN</it>, and upregulation of <it>PIK3C2A</it>, <it>AKT1</it>, <it>PDPK1</it>, <it>RHEB</it>, <it>FRAP1</it>, <it>RPS6KB1</it>, <it>EIF4E </it>and <it>RPS6 </it>in tumors. A similar observation was made for AKT1 and RPS6KB1 expression in tumors at the protein level. Investigation of the mechanism of downregulation of TSC genes identified LOH in 36.96% and 39.13% of the tumors at the TSC1 and TSC2 loci, respectively. No mutation was found in TSC genes. A low LOH rate of 13% was observed at the PTEN locus. Treatment of an OSCC cell line with the methyltransferase inhibitor 5-azacytidine showed a significant increase in the expression of TSC genes, suggesting methylation of their promoters. However, the 5-azacytidine treatment of non-OSCC HeLa cells showed a significant increase in the expression of the <it>TSC2 </it>gene only. In order to confirm the results in patient tumor samples, the methylation status of the <it>TSC2 </it>gene promoter was examined by COBRA. The results suggested promoter hypermethylation as an important mechanism for its downregulation. No correlation was found between the presence or absence of LOH at the TSC1 and TSC2 loci in 50 primary tumors to their clinicopathological variables such as age, sex, T classification, stage, grade, histology, tobacco habits and lymph node metastasis.</p> <p>Conclusion</p> <p>Our study suggests the involvement of TSC genes and other members of the mTOR signaling pathway in the pathogenesis of OSCC. LOH and promoter methylation are two important mechanisms for downregulation of TSC genes. We suggest that known inhibitors of this pathway could be evaluated for the treatment of OSCC.</p