Short‐chain fatty acids affect cell‐association and invasion of HEp‐2 cells by Salmonella typhimurium

Abstract

This study demonstrates that the growth of S. typhimurium in Luria Bertani broth supplemented with acetate, propionate, butyrate, or a mixture of the three SCFA, affected cell‐association and the ability to invade cultured HEp‐2 cells. Cell‐association and invasion was determined after growth for 4 h of growth in the presence of the SCFA at pH 6 and 7. The results suggest that the growth rate of the culture may have affected cell‐association and invasion since accompanying the significant decrease in growth rate in the presence of SCFA at pH 6 was a decrease in cell‐association and invasion. However, the results also suggest that the individual SCFA may play a role in modulating cell‐association and the invasion phenotype and the regulation of cell‐association and invasion by the SCFA was dependent on the concentration and the pH of the medium. Although the growth rates were similar for S. typhimurium in the SCFA mixture, butyrate (100 mM) and propionate (50 mM) at pH 6, differences in cell‐association and invasion were observed among these cultures. Also, at pH 7, differences were observed among the SCFA treatments even though the growth rates were similar.     

Life cycle assessment of ACQ-treated lumber with comparison to wood plastic composite decking

A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to alkaline copper quaternary (ACQ)-treated lumber used for decking and to determine how the impacts compare to the primary alternative product, wood plastic composite (WPC) decking. A model of ACQ-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inventory inputs, outputs, and impact indicators for ACQ-treated lumber were quantified using functional units of 1000 board feet and per representative deck (assumed to be 320 square feet (30 square meters) of surface decking material) per year of use. In a similar manner, an inventory model was developed for the manufacture, use, and disposal of the primary alternative product, WPC. Impact indicator values, including greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, smog forming potential, ecological toxicity, and eutrophication were quantified for each of the two decking products. National normalization was done to compare the significance of a representative deck surface per year of use to a family’s total annual impact footprint.If an average U.S. family adds or replaces a deck surfaced with ACQ-treated lumber, their impact “footprint” for GHG emissions, fossil fuel use, acidification, smog forming potential, ecological toxicity, and eutrophication releases each is less than one-tenth of a percent of the family’s annual impact. ACQ-treated lumber impacts were fourteen times less for fossil fuel use, almost three times less for GHG emissions, potential smog emissions, and water use, four times less for acidification, and almost half for ecological toxicity than those for WPC decking. Impacts were approximately equal for eutrophication.     

Using research-based knowledge to underpin waste and resources policy.

The concept of a knowledge-based approach to policy making (also referred to as 'evidence-based policy making' or 'science meets policy') has been around for 10 years, and is widely 'signed up to' by Governments. This paper examines the theory and the practice at national government (using the UK as a case study) and European levels, looking at how the knowledge-based approach has been applied in waste and resources management. There is general agreement that a knowledge-(or evidence-) based approach to policy making is a 'good thing'; however putting the concept into practice has proven challenging and is still evolving. The linkages between researchers and policy makers need to be further strengthened, as does the 'demand' for evidence from policy; requiring policy specialists to articulate their requirements for evidence sufficiently well in advance, and to do so routinely, is still an area of weakness. Using a model developed by the UK's Department for Environment, Food and Rural Affairs (Defra), we examine in detail some of the implications of changing the question from 'is this good research on waste and resources issues?' to 'is this good evidence for waste and resources policy?'. The paper also provides recommendations for further work required to achieve this at a European level, and for priority areas where international co-ordination of waste and resources research could add most value to policy.     

Estimation of the recycled content of an existing construction project

The Government's Sustainable Buildings Task Group recently recommended a benchmark requirement for a minimum 10% of reused/reclaimed or recycled content (by material value) in construction projects. The benchmark would be implemented through Building Regulations and public sector procurement. This paper presents the findings of a pilot study to inform decision-making on the feasibility of setting and meeting such a requirement.The project involved determining current levels of recycled content in Defence Estates’ standard design for modern barracks accommodation, and quantifying the scope to increase this content. The existing designs for the new barracks were found to use nearly 20% recycled and recovered materials. The project identified opportunities to increase this proportion to nearly 25% with no increase in cost or risk.     

Dissipation of sulfamethoxazole and trimethoprim antibiotics from manure-amended soils

In this study, the dissipation of two antibiotics, sulfamethoxazole (SMX) and trimethoprim (TRM), in three soils under both aerobic and anaerobic conditions are evaluated. Under aerobic conditions, SMX dissipated rapidly through biodegradation but TRM was more persistent. Within the first 20 days in biologically active soils, >50% of the SMX was lost from the clay loam and loamy sand soils, and >80% loss was noted in the loam soil. Anaerobic dissipation of both compounds was more rapid than aerobic dissipation. The addition of manure to the soil only slightly increased the initial dissipation rate of the two compounds. Little effect was found on glucose mineralisation in soil following the addition of SMX and TRM, even as mixtures at high concentrations.     

Using critical systems thinking to foster an integrated approach to sustainability: a proposal for development practitioners

Throughout the development sector, there is increasing recognition of links between the environment and aspects of development such as poverty alleviation, health, income generation, and agriculture. While furnished with a diverse range of perspectives and approaches, development practice is in need of ways to better conceptualize the interactions between the social, environmental, and economic dimensions of sustainability so that opportunities for simultaneous improvement in human and ecological well-being can be identified more readily. Critical systems thinking is proposed as a way for development practitioners to conceptualize and act toward the integration of these economic, social, and environmental dimensions and, in so doing, support communities to nurture both human and ecosystem well-being. Four desirable attributes of a critical systems thinking approach to development are identified based on development literature, critical systems literature, and the author’s research into sustainability in semi-rural communities in Vietnam. The four attributes are ‘a systems thinking approach;’ ‘an ethical base to action and choices;’ ‘critical reflection permeates processes;’ and ‘appreciation of diverse views and application of diverse approaches.’ These attributes are described and then offered as the basis for further discussion of the ways in which simultaneous improvement of human well-being and ecosystem health can become an integral part of development practice.     

Inter-Urban Comparison of Ambient Volatile Organic Compound Concentrations in U.S. Cities

Airborne particulate matter from three ferrous foundries was sampled in granulometric fractions and analyzed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDXA), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) to determine morphology and qualitative bulk and surface chemical compositions. Cluster and principal components analyses (PCA) were used as an aid for interpretation of results. A clear pattern of composition as a function of size emerges; in particular, trace metals accumulate in fine particles and volatile species on the surface of these. Chemical composition changes are also related to daily schedules where applicable: trace metals appear during pouring operations, silicon is generated during mold making and unmolding. Cluster and PCA greatly ease examination of data and offer pictorial representations of results; in particular, the chemical composition versus particle size relationship is very neatly illustrated by PCA graphs.     

Twenty Years of New Zealand’s National Rivers Water Quality Network: Benefits of Careful Design and Consistent Operation1

Davies‐Colley, Robert J., David G. Smith, Robert C. Ward, Graham G. Bryers, Graham B. McBride, John M. Quinn, and Mike R. Scarsbrook, 2011. Twenty Years of New Zealand’s National Rivers Water Quality Network: Benefits of Careful Design and Consistent Operation. Journal of the American Water Resources Association (JAWRA) 47(4):750‐771. DOI: 10.1111/j.1752‐1688.2011.00554.x Abstract: This paper reviews New Zealand’s National Rivers Water Quality Network (NRWQN), which is now in its third decade of monitoring. The NRWQN is noteworthy for being operationally stable throughout its history, and the resulting consistency is increasingly valuable for detecting water quality trends and for “anchoring” temporary special purpose monitoring campaigns. The NRWQN was carefully designed following considerable effort to learn from monitoring experiences elsewhere. Monthly visits are made to 77 sites (all near hydrometric stations) on 35 river systems that cumulatively drain about one half of the national landscape. “Core” (routinely measured) variables are: conductivity, pH, temperature, dissolved oxygen, visual clarity, turbidity, colored dissolved organic matter, fecal indicator bacteria, and different forms of nitrogen and phosphorus (italics indicate field measurements). Associated benthic biological monitoring comprises monthly visual assessment of periphyton and annual sampling for macro‐invertebrates. We overview the conception, design, initiation, and operational history of the NRWQN, and highlight the diverse applications of its datasets including numerous scientific applications, national‐scale modeling of material fluxes, and state‐of‐environment reporting and practical water management at both regional and national scale. The qualified success of the NRWQN can probably be attributed to careful (and parsimonious) design and consistent operation.