In vitro expansion of CD4+CD25highFOXP3+CD127low/- regulatory T cells from peripheral blood lymphocytes of healthy Mycobacterium tuberculosis-infected humans.

CD4+CD25highFOXP3+ regulatory T (Treg) cells have recently been found at elevated levels in the peripheral blood of tuberculosis patients, compared to Mycobacterium tuberculosis latently infected (LTBI) healthy individuals and non-infected controls. Here, we show that CD4+CD25highFOXP3+ T lymphocytes can be expanded in vitro from peripheral blood mononuclear cells (PBMC) of LTBI individuals, but not of uninfected controls by incubating them with BCG in the presence of TGF-beta. These expanded cells from the PBMC of LTBI subjects expressed CTLA-4, GITR and OX-40, but were CD127low/- and have therefore the phenotype of Treg cells. In addition, they inhibited in a dose-dependant manner the proliferation of freshly isolated mononuclear cells in response to polyclonal stimulation, indicating that they are functional Treg lymphocytes. In contrast, incubation of the PBMC with BCG alone preferentially induced activated CD4+ T cells, expressing CD25 and/or CD69 and secreting IFN-gamma. These results show that CD4+CD25highFOXP3+ Treg cells can be expanded or induced in the peripheral blood of LTBI individuals in conditions known to predispose to progression towards active tuberculosis and may therefore play an important role in the pathogenesis of the disease.

Key role of effector memory CD4+ T lymphocytes in a short-incubation heparin-binding hemagglutinin gamma interferon release assay for the detection of latent tuberculosis

info:eu-repo/semantics/published

Monitoring SO2 emission at the Soufriere Hills Volcano: implications for changes in eruptive conditions

info:eu-repo/semantics/published

Biological and demographic response of aphids Nasonovia ribisnigri (Mosley) and Aulacorthum solani (Kaltenbach) (Hemiptera : Aphididae) on lettuce commercial cultivars under laboratory conditions

p.17-24

Biological and demographic response of aphids Nasonovia ribisnigri (Mosley) and Aulacorthum solani (Kaltenbach) (Hemiptera : Aphididae) on lettuce commercial cultivars under laboratory conditions

p.17-24

Monotone scheme and boundary conditions for finite volume simulation of magnetohydrodynamic internal flows at high Hartmann number

A monotone scheme for finite volume simulation of magnetohydrodynamic internal flows at high Hartmann number is presented. The numerical stability is analysed with respect to the electromagnetic force. Standard central finite differences applied to finite volumes can only be numerically stable if the vector products involved in this force are computed with a scheme using a fully staggered grid. The electromagnetic quantities (electric currents and electric potential) must be shifted by half the grid size from the mechanical ones (velocity and pressure). An integral treatment of the boundary layers is used in conjunction with boundary conditions for electrically conducting walls. The simulations are performed with inhomogeneous electrical conductivities of the walls and reach high Hartmann numbers in three-dimensional simulations, even though a non-adaptive grid is used.

Modelling occupant interaction with fire conditions using the buildingEXODUS evacuation model

When evacuating through fire environments, the presence of smoke may not only have a physiological impact on the evacuees but may also lead occupants to adapt their evacuation strategy through the adoption of another exit. This paper attempts to introduce this type of adaptive behaviour within the buildingEXODUS evacuation model through enabling occupants to make decisions concerning the selection of the most viable available exit during an evacuation involving fire. The development of this adaptive behaviour requires the introduction of several new capabilities namely, the representation of the occupants’ familiarity with the structure, the behaviour of an occupant that is engulfed in smoke and the behaviour of an occupant that is faced with a smoke barrier. The appropriateness of the redirection decision is dependent upon behavioural data gathered from real fire incidents (in the UK and USA) that is used to construct the redirection probabilities. The implementation is shown to provide a more complex and arguably more realistic representation of this behaviour than that provided previously.

The simulation of ship evacuation under fire conditions

When designing a new passenger ship or modifying an existing design, how do we ensure that the proposed design and crew emergency procedures are safe from an evacuation resulting from fire or other incident? In the wake of major maritime disasters such as the Scandinavian Star, Herald of Free Enterprise, Estonia and in light of the growth in the numbers of high density, high-speed ferries and large capacity cruise ships, issues concerning the evacuation of passengers and crew at sea are receiving renewed interest. Fire and evacuation models with features such as the ability to realistically simulate the spread of fire and fire suppression systems and the human response to fire as well as the capability to model human performance in heeled orientations linked to a virtual reality environment that produces realistic visualisations of the modelled scenarios are now available and can be used to aid the engineer in assessing ship design and procedures. This paper describes the maritimeEXODUS ship evacuation and the SMARTFIRE fire simulation model and provides an example application demonstrating the use of the models in performing fire and evacuation analysis for a large passenger ship partially based, but exceeding the requirements of MSC circular 1033.

Using computer models to identify optimal conditions for flip-chip assembly and reliability

Flip-chip assembly, developed in the early 1960s, is now being positioned as a key joining technology to achieve high-density mounting of electronic components on to printed circuit boards for high-volume, low-cost products. Computer models are now being used early within the product design stage to ensure that optimal process conditions are used. These models capture the governing physics taking place during the assembly process and they can also predict relevant defects that may occur. Describes the application of computational modelling techniques that have the ability to predict a range of interacting physical phenomena associated with the manufacturing process. For example, in the flip-chip assembly process we have solder paste deposition, solder joint shape formation, heat transfer, solidification and thermal stress. Illustrates the application of modelling technology being used as part of a larger UK study aiming to establish a process route for high-volume, low-cost, sub-100-micron pitch flip-chip assembly.

Predicting optimal process conditions for flip-chip aassembly using copper column bumped dies

Recently, research has been carried out to test a novel bumping method which omits the under bump metallurgy (UBM) forming process by bonding copper columns directly onto the Al pads of the silicon dies. This bumping method could be adopted to simplify the flip chip assembly process, increase the productivity and achieve a higher I/O count. Computer modelling methods are used to predict the shape of solder joints and response of the flip chip to thermal cyclic loading. The accumulated plastic strain energy at the comer solder joints is used as the damage indicator. Models with a range of design parameters have been compared for their reliability. The ranking of the relative importance of these parameters is given. Results from these analyses are being used by our industrial and academic partners to identify optimal design conditions.

A computational model of coupled heat and moisture transfer with phase change in granular sugar during varying environmental conditions

As part of a comprehensive effort to predict the development of caking in granular materials, a mathematical model is introduced to model simultaneous heat and moisture transfer with phase change in porous media when undergoing temperature oscillations/cycling. The resulting model partial differential equations were solved using finite-volume procedures in the context of the PHYSICA framework and then applied to the analysis of sugar in storage. The influence of temperature on absorption/desorption and diffusion coefficients is coupled into the transport equations. The temperature profile, the depth of penetration of the temperature oscillation into the bulk solid, and the solids moisture content distribution were first calculated, and these proved to be in good agreement with experimental data. Then, the influence of temperature oscillation on absolute humidity, moisture concentration, and moisture migration for different parameters and boundary conditions was examined. As expected, the results show that moisture near boundary regions responds faster than farther away from them with surface temperature changes. The moisture absorption and desorption in materials occurs mainly near boundary regions (where interactions with the environment are more pronounced). Small amounts of solids moisture content, driven by both temperature and vapour concentration gradients, migrate between boundary and center with oscillating temperature.

Simulating the interaction of cabin crew with passengers during aircraft emergency evacuation conditions

In this paper we briefly describe new modelling capabilities within the airEXODUS evacuation model. These new capabilities involve the explicit ability to simulate the interaction of crew with passengers in managing evacuation situations

Mistake, frustration and implied conditions in leases

Discusses the Court of Appeal decision in Graves v Graves on determination of a tenancy by reason of common mistake and frustration. Reviews earlier case law regarding the effects on a contract of a common mistake or frustrating event. Considers the effect of the common mistaken belief held by the parties in Graves when executing a tenancy agreement that the tenant would be entitled to housing benefit, in particular whether by reason of it a condition was implied into the tenancy that the contract would be terminated if housing benefit was unavailable.