1,396 research outputs found
Situational Factors Contributing to The Expression of Aggression on The Roads
This study explored the influence of situational factors on aggressive driving from within the framework of a frustration-aggression model of aggressive driving. Through the use of driving scenarios, a number of situational characteristics were manipulated to examine their effect on the level of anger reported by participants and their likely behavioural response. The situational characteristics examined included the age, gender and anonymity of the offending driver, and the sense of time pressure as well as the gender of the participants. The results confirmed that the situational characteristics of a potentially frustrating road event can influence both the anger reported by participating drivers and their likely behavioural response
Preliminary steps toward artificial protocell computation
Protocells are hypothesised as a transitional phase in the origin of life, prior to the evolution of fully functional prokaryotic cells. The work reported here is being done in the context of the PACE project, which is investigating the fabrication of artificial protocells de novo. We consider here the important open question of whether or how articifial protocells (if or when they are successfully
fabricated) might be applied as âcomputingâ devicesâwhat sort of computing might they be suitable for, and how might they be âprogrammedâ? We also present some preliminary analysis of a crude model of such âevolutionary protocell computationâ
SITUATIONAL FACTORS CONTRIBUTING TO THE EXPRESSION OF AGGRESSION ON THE ROADS
This study explored the influence of situational factors on aggressive driving from within the framework of a frustration-aggression model of aggressive driving. Through the use of driving scenarios, a number of situational characteristics were manipulated to examine their effect on the level of anger reported by participants and their likely behavioural response. The situational characteristics examined included the age, gender and anonymity of the offending driver, and the sense of time pressure as well as the gender of the participants. The results confirmed that the situational characteristics of a potentially frustrating road event can influence both the anger reported by participating drivers and their likely behavioural response
On Protocell "Computation"
The EU FP6 Integrated Project PACE ('Programmable Artificial Cell Evolution') is investigating the creation, de novo, of chemical 'protocells'. These will be minimal 'wetware' chemical systems integrating molecular information carriers, primitive energy conversion (metabolism) and containment (membrane). Ultimately they should be capable of autonomous reproduction, and be 'programmable' to realise specific desired function. A key objective of PACE is to explore the application of such protocell technology to build novel nanoscale computational devices. In principle, such computation might be realised either at the level of an individual protocell or at the level of self-assembling, multi-cellular, aggregates. In the case of the individual protocell level, a form of 'molecular computation' may be possible in the manner of 'cell signalling networks' in modern cells. This might be particularly appropriate where a protocell is deployed to interface directly with molecular systems, such as in 'smart drug' applications. 'Programming' of molecular computation functionality might be realised by evolutionary techniques, i.e., applying selection to polulations of (reproducing) protocells. Reflexive string rewriting systems may provide an appropriate formal model of molecular computation. The behaviour of minimal reflexive string rewriting systems, incorporated in reproducing containers (protocells), is being explored in simulation. This is a basis for possible design of minimal protocell 'computers'
Mesenchymal stem cells expressing TRAIL lead to tumour growth inhibition in an experimental lung cancer model
AbstractLung cancer is a major public health problem in the western world, and gene therapy strategies to tackle this disease systemically are often impaired by inefficient delivery of the vector to the tumour tissue. Some of the main factors inhibiting systemic delivery are found in the blood stream in the form of red and white blood cells (WBCs) and serum components. Mesenchymal stem cells (MSCs) have been shown to home to tumour sites and could potentially act as a shield and vehicle for a tumouricidal gene therapy vector. Here, we describe the ability of an adenoviral vector expressing TRAIL (Ad.TR) to transduce MSCs and show the apoptosisâinducing activity of these TRAILâcarrying MSCs on A549 lung carcinoma cells. Intriguingly, using MSCs transduced with Ad.enhancedâgreenâfluorescentâprotein (EGFP) we could show transfer of viral DNA to cocultured A549 cells resulting in transgenic protein production in these cells, which was not inhibited by exposure of MSCs to human serum containing high levels of adenovirus neutralizing antibodies. Furthermore, Ad.TRâtransduced MSCs were shown not to induce Tâcell proliferation, which may have resulted in cytotoxic Tâcellâmediated apoptosis induction in the Ad.TRâtransduced MSCs. Apoptosis was also induced in A549 cells by Ad.TRâtransduced MSCs in the presence of physiological concentrations of WBC, erythrocytes and sera from human donors that inhibit or neutralize adenovirus alone. Moreover, we could show tumour growth reduction with TRAILâloaded MSCs in an A549 xenograft mouse model. This is the first study that demonstrates the potential therapeutic utility of Ad.TRâtransduced MSCs in cancer cells and the stability of this vector in the context of the blood environment.</jats:p
Self-pulsation at 480 GHz from a two-color discrete mode laser diode
A discrete mode Fabry-PĂ©rot laser is designed and fabricated to achieve two-color lasing. We demonstrate beating between the two laser modes and self-pulsation at 480 GHz
Swift observations of the 2006 outburst of the recurrent nova RS Ophiuchi: III. X-ray spectral modelling
Following the Swift X-ray observations of the 2006 outburst of the recurrent
nova RS Ophiuchi, we developed hydrodynamical models of mass ejection from
which the forward shock velocities were used to estimate the ejecta mass and
velocity. In order to further constrain our model parameters, here we present
synthetic X-ray spectra from our hydrodynamical calculations which we compare
to the Swift data. An extensive set of simulations was carried out to find a
model which best fits the spectra up to 100 days after outburst. We find a good
fit at high energies but require additional absorption to match the low energy
emission. We estimate the ejecta mass to be in the range (2-5) x 10^{-7} solar
masses and the ejection velocity to be greater than 6000 km/s (and probably
closer to 10,000 km/s). We also find that estimates of shock velocity derived
from gas temperatures via standard model fits to the X-ray spectra are much
lower than the true shock velocities.Comment: 13 pages, 5 figures, Accepted for publication in Ap
Inverse scattering approach to multiwavelength Fabry-PĂ©rot laser design
A class of multiwavelength Fabry-Pérot lasers is introduced where the spectrum is tailored through a patterning of the cavity effective index. The cavity geometry is obtained using an inverse scattering approach and can be designed such that the spacing of discrete Fabry-Pérot lasing modes is limited only by the bandwidth of the inverted gain medium. A specific two-color semiconductor laser with a mode spacing in the THz region is designed, and measurements are presented demonstrating the simultaneous oscillation of the two wavelengths. The nonperiodic effective index profile of the particular two-color device considered is shown to be related to a Moiré or superstructure grating
Effects of single mutations on the stability of horseradish peroxidase to hydrogen peroxide
Horseradish peroxidase (HRP) is a commonly used enzyme in many biotechnological fields. Improvement of HRP stability would further increase its potential application range. In the present study, 13 single- and three double-mutants of solvent exposed, proximal lysine and glutamic acid residues were analysed for enhanced H2O2 stability. Additionally, five single- and one pentuple-consensus mutants were investigated. Most mutants displayed little or no alteration in H2O2 stability; however, three (K232N, K241F and T110V) exhibited significantly increased H2O2 tolerances of 25- (T110V), 18- (K232N), and 12-fold (K241F). This improved stability may be due to an altered enzyme-H2O2 catalysis pathway or to removal of potentially oxidisable residues
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