181 research outputs found
A black Bonhoeffer?
This paper offers an assessment of the lifework of the African-American theologian and Civil Rights leader James H. Cone (1935–2018) by cataloguing parallels with the life and career of the German theologian Dietrich Bonhoeffer (1906-1945). Bonhoeffer's experience of studying in the US and his opposition to the Nazis provides an interesting counterpoint to Cone's development of a Black Theology that emerged from his struggles on behalf of the black community, his deep connection with spirituals and the blues, and his uncompromising commitment to following Christ
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Experimental Simulation of Volatile Organic Contributions to Planetary Atmospheres and Surfaces
We present the results of a new simulation of the atmospheric entry heating experienced by extraterrestrial dust particles, quantifying their volatile loss into the early Earth atmosphere and characterising their organic volatile components
Asthma and PM10
PM(10) (the mass of particles present in the air having a 50% cutoff for particles with an aerodynamic diameter of 10 μm) is the standard measure of particulate air pollution used worldwide. Epidemiological studies suggest that asthma symptoms can be worsened by increases in the levels of PM(10). Epidemiological evidence at present indicates that PM(10) increases do not raise the chances of initial sensitisation and induction of disease, although further research is warranted. PM(10) is a complex mixture of particle types and has many components and there is no general agreement regarding which component(s) could lead to exacerbations of asthma. However pro-inflammatory effects of transition metals, hydrocarbons, ultrafine particles and endotoxin, all present to varying degrees in PM(10), could be important. An understanding of the role of the different components of PM(10) in exacerbating asthma is essential before proper risk assessment can be undertaken leading to advice on risk management for the many asthmatics who are exposed to air pollution particles
Managing multi-platform materials: selected case studies.
Mobile devices and Internet usage are now common in most parts of the world. Archives and other cultural agencies are challenged by the increasing amounts, and complexity, of digital content. New strategies are being developed and promoted to enable digital acquisition and preservation. The National Film and Sound Archive of Australia (NFSA) is examining and addressing acquisition and preservation challenges for a range of complex digital content, within available resources. This paper will discuss issues associated with a range of multi-platform content with reference to selected case studies
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Hydropyrolysis of insoluble carbonaceous matter in the Murchison meteorite
Metal composition of ambient PM2.5 influences severity of allergic airways disease in mice.
Children living in Hettstedt in eastern Germany have been reported to have a higher prevalence of sensitization to common aeroallergens than another cohort living in the neighboring city of Zerbst; these differences correlated with the presence of industrial air pollution. Samples of fine particulate matter (< 2.5 micro m aerodynamic diameter; PM(2.5)) collected in Hettstedt in 1999 had several-fold higher levels of zinc, magnesium, lead, copper, and cadmium than samples from Zerbst. To determine if the results from epidemiologic studies could be repeated in an animal model, we administered PM(2.5) from Hettstedt and Zerbst to ovalbumin-allergic mice. In Balb/c mice, PM(2.5) from Hettstedt, but not PM(2.5) from Zerbst or control filter extract, caused a significant increase in immediate responses to ovalbumin challenge when aspirated 2 hr before challenge, but not when aspirated immediately before sensitization 2 weeks earlier. Antigen-specific IgE was increased by Hettstedt PM(2.5) whether administered before sensitization or challenge. Airway responsiveness to methacholine aerosol and lung inflammatory cell numbers were significantly increased only in allergic mice exposed to Hettstedt PM(2.5) before challenge. Both Hettstedt and Zerbst PM(2.5) significantly increased lung injury parameters and proinflammatory cytokines. These results are consistent with epidemiologic findings and show that metal composition of ambient PM(2.5) influences the severity of allergic respiratory disease
Crops in the woolbelt : current options and emerging prospects
It has traditionally been more profitable to grow sheep for wool in the medium rainfall parts of the south-west of Western Australia than to grow crops . Crop production has been difficult owing to the hilly terrain, the frequency of waterlogging, the high incidence of damaging frosts in some areas, the frequency of losses from diseases, difficulties with wet weather at harvest, and a lack of adapted crop varieties.
Advances over the past decade have made cropping on a limited scale potentially profitable in the woo/belt.
This article is intended to bring the various options for crop production to the attention of wool growers. Further detailed information will be required for successful production and is available from your local office of the Department of Agriculture
Probing the interstellar medium using laboratory samples
The aim of this thesis is to investigate the effects of interstellar processing using presolar samples. Dust in the interstellar medium is predicted to have experienced grain-grain and grain-gas collisions, cosmic-ray bombardment, or the formation of ices on their surfaces. Each process is likely to have altered presolar grains. The grains are extracted from meteorites and can be analyzed in the laboratory to try and understand these processes. The main analytical tool used in this research was a new time-of-flight secondary ion mass spectrometry instrument equipped with a Au-cluster primary ion source. Analysis of presolar grains required that a rigorous experimental procedure was developed. A depth-profiling technique for the analysis of micron-sized samples was produced and the limitations of the technique considered. Secondary ion mass spectrometry suffers from matrix effects, so homogeneous silicate glass standards were analyzed. The use of Au-cluster primary ions was shown to enhance practical secondary ion yields relative to those with Au+, consistent with increased sputter rates. Relative sensitivity factors for major and trace elements in the standards were obtained using both normal and delayed secondary ion extraction techniques. Depth-profiles of Li, B, Mg, Al, K, Ca, Ti, V, Cr and Fe were obtained from eleven presolar SiC grains. In some SiC grains, the abundances of several elements were up to orders-of-magnitude higher in the outer ~200nm relative to the grain cores. This was attributed to the implantation of interstellar matter, accelerated to velocities of ~1000kms-1 by supernovae shockwaves. Other SiC grains contained homogeneously distributed trace elements, or evidence of elemental zoning, which could be explained by condensation processes around the grains' parent stars. These grains must have experienced minimal processing in the interstellar medium. It is suggested that the two populations represent SiC grains whose residence times in the interstellar medium significantly differed, consistent with previous findings of noble gas and Li isotopic studies. A further study investigated carbonaceous grains isolated from the Murchison meteorite using a size and density procedure adapted for presolar graphite. No graphite grains were found and possible reasons for this are discussed. The structural and isotopic natures of thirty-three carbonaceous grains were determined by correlated, multi-instrument analyses. The grains contained solar C, N and O isotopic compositions. Deuterium was enriched in the grains with δD values up to +333 ± 110‰. These enrichments suggest exchange of H with cold interstellar gas in the outer part of the early solar nebula or interstellar medium. Raman spectroscopic and transmission electron microscopic analysis showed the grains to be composed of carbon more structurally disordered and amorphous than most carbonaceous phases observed in extra-terrestrial samples. It is argued that amorphization of the grains occurred through solar wind ion irradiation in the proto-solar nebula. This model is supported by previous studies of terrestrial soot and carbon-rich ices irradiated by H⁺ and He⁺ ion doses of ~10¹⁵ - 10¹⁶ ions cm⁻². Implantation and mixing of H⁺ ions is likely to have diluted the grains' original H isotopic composition.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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