Oxidative Stress Resulting From Helicobacter pylori Infection Contributes to Gastric Carcinogenesis.

Helicobacter pylori is a gram-negative, microaerophilic bacterium that infects the stomach and can lead to, among other disorders, the development of gastric cancer. The inability of the host to clear the infection results in a chronic inflammatory state with continued oxidative stress within the tissue. Reactive oxygen species and reactive nitrogen species produced by the immune and epithelial cells damage the host cells and can result in DNA damage. H pylori has evolved to evoke this damaging response while blunting the host's efforts to kill the bacteria. This long-lasting state with inflammation and oxidative stress can result in gastric carcinogenesis. Continued efforts to better understand the bacterium and the host response will serve to prevent or provide improved early diagnosis and treatment of gastric cancer

A homomorphism theorem and a Trotter product formula for quantum stochastic flows with unbounded coefficients

We give a new method for proving the homomorphic property of a quantum stochastic ow satisfying a quantum stochastic differential equation with unbounded coefficients, under some further hypotheses. As an application, we prove a Trotter product formula for quantum stochastic ows and obtain quantum stochastic dilations of a class of quantum dynamical semigroups generalizing results of [5

Demonstration of angular anisotropy in the output of Thematic Mapper

There is a dependence of TM output (proportional to scene radiance in a manner which will be discussed) upon season, upon cover type and upon view angle. The existence of a significant systematic variation across uniform scenes in p-type (radiometrically and geometrically pre-processed) data is demonstrated. Present pre-processing does remove the effects and the problem must be addressed because the effects are large. While this is in no way attributable to any shortcomings in the thematic mapper, it is an effect which is sufficiently important to warrant more study, with a view to developing suitable pre-processing correction algorithms

Fit for work? Health, employability and challenges for the UK welfare reform agenda

This article introduces a special issue of Policy Studies entitled “Fit for work? Health, employability and challenges for the UK welfare reform agenda”. Growing from a shared concern over the need to expand the evidence base around the processes that led to large numbers of people claiming disability benefits in the UK, it brings together contributions from leading labour market and social policy researchers providing evidence and commentary on major reforms to Incapacity Benefit (IB) in the UK. This special issue address three key questions: what are the main causes of the long-term rise in the number of people claiming IBs; what will reduce the number of claimants; and what is likely to deliver policy effectively and efficiently? This introduction first explains and examines the challenges to reforms to IB in the UK, and then, in conclusion, highlights the answers to the previous three questions – first, labour market restructuring and marginalisation have driven the rise in numbers claiming IBs. Second, economic regeneration in the Britain’s less prosperous areas coupled with intensive and sustained supply-side support measures will bring numbers down. Third, delivery need to be flexible and tailored to individual needs and needs to be able to access local and expert knowledge in a range of organisations, including Job Centre Plus, the NHS as well as the private and voluntary sectors

Radiative absorption enhancements by black carbon controlled by particle-to-particle heterogeneity in composition.

Black carbon (BC) absorbs solar radiation, leading to a strong but uncertain warming effect on climate. A key challenge in modeling and quantifying BC's radiative effect on climate is predicting enhancements in light absorption that result from internal mixing between BC and other aerosol components. Modeling and laboratory studies show that BC, when mixed with other aerosol components, absorbs more strongly than pure, uncoated BC; however, some ambient observations suggest more variable and weaker absorption enhancement. We show that the lower-than-expected enhancements in ambient measurements result from a combination of two factors. First, the often used spherical, concentric core-shell approximation generally overestimates the absorption by BC. Second, and more importantly, inadequate consideration of heterogeneity in particle-to-particle composition engenders substantial overestimation in absorption by the total particle population, with greater heterogeneity associated with larger model-measurement differences. We show that accounting for these two effects-variability in per-particle composition and deviations from the core-shell approximation-reconciles absorption enhancement predictions with laboratory and field observations and resolves the apparent discrepancy. Furthermore, our consistent model framework provides a path forward for improving predictions of BC's radiative effect on climate

Alternatives to Electric Air Conditioning Systems

The rapid escalation of electricity prices has created an opportunity to re-introduce gas-fired air conditioning systems to the commercial building market. In 1985 Gas Research Institute initiated a program to develop an advanced gas engine-driven water chiller. The packaged system has been designed, fabricated and tested. A field experiment unit has been operating since August, 1986, and seven field test units have been operating since April, 1987. The performance of the system has been outstanding. The system should be an economically attractive alternative to electrically-driven chillers in most of the United States

Impacts of an extreme cyclone event on landscape-scale savanna fire, productivity and greenhouse gas emissions

North Australian tropical savanna accounts for 12% of the world\u27s total savanna land cover. Accordingly, understanding processes that govern carbon, water and energy exchange within this biome is critical to global carbon and water budgeting. Climate and disturbances drive ecosystem carbon dynamics. Savanna ecosystems of the coastal and sub-coastal of north Australia experience a unique combination of climatic extremes and are in a state of near constant disturbance from fire events (1 in 3 years), storms resulting in windthrow (1 in 5–10 years) and mega-cyclones (1 in 500–1000 years). Critically, these disturbances occur over large areas creating a spatial and temporal mosaic of carbon sources and sinks. We quantify the impact on gross primary productivity (GPP) and fire occurrence from a tropical mega-cyclone, tropical Cyclone Monica (TC Monica), which affected 10 400 km2 of savanna across north Australia, resulting in the mortality and severe structural damage to ~140 million trees. We estimate a net carbon equivalent emission of 43 Tg of CO2-e using the moderate resolution imaging spectroradiometer (MODIS) GPP (MOD17A2) to quantify spatial and temporal patterns pre- and post-TC Monica. GPP was suppressed for four years after the event, equivalent to a loss of GPP of 0.5 Tg C over this period. On-ground fuel loads were estimated to potentially release 51.2 Mt CO2-e, equivalent to ~10% of Australia\u27s accountable greenhouse gas emissions. We present a simple carbon balance to examine the relative importance of frequency versus impact for a number of key disturbance processes such as fire, termite consumption and intense but infrequent mega-cyclones. Our estimates suggested that fire and termite consumption had a larger impact on Net Biome Productivity than infrequent mega-cyclones. We demonstrate the importance of understanding how climate variability and disturbance impacts savanna dynamics in the context of the increasing interest in using savanna landscapes for enhanced carbon sinks in emission offset schemes