The effects of malnutrition on secretory and cellular immune processes.

About 15 million children under 5 years of age die each year due to suppressed immunity and the resulting increased infection. In severely malnourished children and animals some immune systems such as T-cell function, secretory IgA and complement are significantly suppressed. Other systems, such as the serum IgG or IgA, are normal or even elevated. Some of these changes are apparently caused by nutritional stress while others may be due to stimulation by increased incidence of infection and antigen load. On the other hand, marginal malnutrition stimulates increased phagocytosis and T-cell function with increased immunity to cancer but decreased resistance to certain microbial agents. The mechanisms of immune suppression by malnutrition, persistence of these effects after renutrition, and the effect of maternal malnutrition on newborn immunity are critically reviewed. Possible non-nutritional means of rapid immunological restoration of malnourished children are described.     

Severn Barrage tidal power project: implications for carbon emissions

UK Government encouragement of the Severn Barrage project has regard for the fact that this is by far the largest single source of renewable energy available to the United Kingdom. A major concern for all forms of electricity generation is their effects of carbon emissions and, as a result which is now generally recognised, on global warming. The present paper makes use of published sources of carbon emissions data to estimate the carbon content of each of the operations required to produce, transport, construct, operate and decommission this barrage if it is located and designed as set out in 1989. The approach adopted here is based on estimating the ratio of the life-cycle carbon emissions demand of the scheme (gCO₂) relative to its energy output (kW) over an assumed lifetime, this to include expected plant replacements over that period.     

Ashmolean Museum,Oxford

In November 2009, the Ashmolean Museum opened a new extension that doubled its gallery space on its existing city centre site. Howard Watson looks at how the redevelopment of the museum has been to its benefit curatorially, optimising the display space available for its extensive collections, but also enabling new connections to be made between artefacts in a way that fully tells the stories of civilisations across the globe. Copyright © 2010 John Wiley & Sons, Ltd.     

Therapeutic effects of novel resin bonding systems containing bioactive glasses on mineral-depleted areas within the bonded-dentine interface

This study aimed in evaluating the effects of two experimental resin bonding systems containing conventional Bioglass 45S5 (BAG) or Zinc-polycarboxylated bioactive glass (BAG-Zn) micro-fillers on the resin-bonded dentine interface after storage in a simulated body fluid solution (SBFS). Three resin bonding systems were formulated: Resin-A: (BAG containing); Resin-B; (BAG-Zn containing); Resin-C (no filler). The ability of the experimental resins to evoke apatite formation was evaluated using confocal Raman spectroscopy. Acid-etched dentine specimens were bonded, and prepared for AFM/nano-indentation analysis in a fully-hydrated status to evaluate the modulus of elasticity (Ei) and hardness (Hi) across the interface at different SBFS storage periods. Further resin-dentine specimens were tested for microtensile bond strength after 24 h or 3 months of SBFS storage. SEM examination was performed after de-bonding and confocal laser microscopy was used to evaluate the ultramorphology of the interfaces and micropermeability. The resin A and B showed a consistent presence of apatite (967 cm(-1)), reduced micropermeability within the resin-dentine interface and a significant increase of the Ei and Hi along the bonded-dentine interface after prolonged SBFS storage. Bond strength values were affected by the resin system (P < 0.0001) and by storage time (P < 0.0001) both after 24 h and 3 months of SBFS storage. In conclusion, resin bonding systems containing bioactive fillers may a have therapeutic effect on the nano-mechanical properties and sealing ability of mineral-depleted resin-dentine interface.     

Nitrogen processing by biofilms along a lowland river continuum

While numerous studies have examined N dynamics along a river continuum, few have specifically examined the role of biofilms. Nitrogen dynamics and microbial community structure were determined on biofilms at six sites along a 120 km stretch of the lowland Ovens River, South Eastern Australia using artificial substrates. Terminal restriction fragment length polymorphism (T‐RFLP), chlorophyll a and protein analyses were used to assess biofilm microbial community composition. N dynamics was determined on the biofilms using the acetylene (C₂H₂) block technique and assessing changes in NH, NO_x and N₂O. Unlike microbial community structure, N dynamics were spatially heterogeneous. Nitrification, determined from the difference in accumulation of NH before and after addition of C₂H₂, occurred mostly in the upper sites with rates up to 1.4 × 10^?5 mol m^?2 h^?1. The highest rates of denitrification occurred in the mid‐reaches of the river (with rates up to 1 × 10^?5 mol m^?2 h^?1) but denitrification was not detected in the lower reaches. At the very most, only 50% of the observed uptake of NO_x by the biofilms following addition of C₂H₂ could be accounted for by denitrification. Copyright © 2005 John Wiley & Sons, Ltd.     

Pilot-scale in situ bioremedation of uranium in a highly contaminated aquifer. 2. Reduction of u(VI) and geochemical control of u(VI) bioavailability

In situ microbial reduction of soluble U(VI) to sparingly soluble U(IV) was evaluated at the site of the former S-3 Ponds in Area 3 of the U.S. Department of Energy Natural and Accelerated Bioremediation Research Field Research Center, Oak Ridge, TN. After establishing conditions favorable for bioremediation (Wu, et al. Environ. Sci. Technol. 2006, 40, 3988-3995), intermittent additions of ethanol were initiated within the conditioned inner loop of a nested well recirculation system. These additions initially stimulated denitrification of matrix-entrapped nitrate, but after 2 months, aqueous U levels fell from 5 to approximately 1 microM and sulfate reduction ensued. Continued additions sustained U(VI) reduction over 13 months. X-ray near-edge absorption spectroscopy (XANES) confirmed U(VI) reduction to U(IV) within the inner loop wells, with up to 51%, 35%, and 28% solid-phase U(IV) in sediment samples from the injection well, a monitoring well, and the extraction well, respectively. Microbial analyses confirmed the presence of denitrifying, sulfate-reducing, and iron-reducing bacteria in groundwater and sediments. System pH was generally maintained at less than 6.2 with low bicarbonate level (0.75-1.5 mM) and residual sulfate to suppress methanogenesis and minimize uranium mobilization. The bioavailability of sorbed U(VI) was manipulated by addition of low-level carbonate (< 5 mM) followed by ethanol (1-1.5 mM). Addition of low levels of carbonate increased the concentration of aqueous U, indicating an increased rate of U desorption due to formation of uranyl carbonate complexes. Upon ethanol addition, aqueous U(VI) levels fell, indicating that the rate of microbial reduction exceeded the rate of desorption. Sulfate levels simultaneously decreased, with a corresponding increase in sulfide. When ethanol addition ended but carbonate addition continued, soluble U levels increased, indicating faster desorption than reduction. When bicarbonate addition stopped, aqueous U levels decreased, indicating adsorption to sediments. Changes in the sequence of carbonate and ethanol addition confirmed that carbonate-controlled desorption increased bioavailability of U(VI) for reduction.     

Control of high-speed machines

The author explores the theme of high-speed machinery control through examples taken from a DTI Link programme and considers the role of technology transfer in product development     

Phagomagnetic separation-quantitative PCR: A rapid,sensitive and specific surveillance tool for viable Mycobacterium avium ssp. paratuberculosis in bulk tank and individual cow milk samples

Bulk tank milk samples from 392 Northern Ireland dairy farms and individual milk from animals (n = 293) on 4 of these farms were tested by a novel phagomagnetic separation (PhMS)-quantitative (q)PCR assay able to detect and quantify viable Mycobacterium avium ssp. paratuberculosis (MAP), to demonstrate its potential utility as a milk surveillance tool. Viable MAP were detected in 26.5% of the bulk tank milks, with MAP contamination levels ranging from 1 to 8,432 MAP/50 mL of milk; less than 2% of farms had MAP contamination levels >100 MAP/50 mL in their bulk tank milk. Follow-up PhMS-qPCR testing of milk from individual animals on 4 farms that had the highest numbers of MAP in their bulk tank milks indicated that 17 to 24% of animals in each herd were shedding viable MAP in their milk. Mean MAP numbers detected ranged between 6.7 and 42.1 MAP/50 mL of milk. No significant correlation was observed between the detection of viable MAP in bulk or individual milks by PhMS-qPCR and parallel milk ELISA results, or between PhMS-qPCR results and any other milk recording results (somatic cell count, total bacterial count, % butterfat, or % protein). Viable MAP was detected by IS900 qPCR in 52 (85.2%) Pozzato broth cultures of 61 PhMS-qPCR-positive individual milks after 12 wk of incubation, suggesting few PhMS-qPCR results were false positives. The mean sensitivities of the PhMS-qPCR assay and milk ELISA applied to individual milks were estimated by Bayesian latent class analysis to be 0.7096 and 0.2665, respectively, and mean specificities were similar (0.9626 and 0.9509). Our findings clearly demonstrate that the novel PhMS-qPCR assay could be a useful milk surveillance tool for dairy processors, or a milk monitoring tool for Johne's disease control or milk quality assurance programs.     

Structural characterization of two synthetic catalysts based on adipocyte lipid-binding protein

Adipocyte lipid-binding protein (ALBP) is a small (14.5 kDa) 10- strandedbeta-barrel protein found in mammalian fat cells. The crystal structures ofvarious holo-forms of ALBP have been solved and show the fatty acid ligandbound in a large (approximately 400 A3) cavity isolated from bulk solvent.Examination of the cavity suggests that it would be a good site for thecreation of an artificial catalyst, as numerous well defined crystalstructures of ALBP are available and past studies have shown theconformation to be reasonably tolerant to modification and mutagenesis.Previous work has shown ALBP to be a good protein scaffold for exploringenantio- and stereoselective reactions; two constructs, ALBP attached toeither a pyridoxamine or a phenanthroline group at C117, have beenchemically characterized. Both modified proteins have been crystallized andtheir structures solved and refined. The X-ray models have been used toexamine the origin of the chiral selectivity seen in the products. It isapparent that these covalent adducts reduce the internal cavity volume,sterically limiting substrate interactions with the reactive groups, aswell as solvent access to potential intermediates in the reaction pathway.