Characterization of silicon dioxide for a capacitance-type meteoroid penetration detector

Fabrication and testing of large area metal oxide silicon capacitors for micrometeoroid counting in spac

The strong influence of substrate conductivity on droplet evaporation

We report the results of physical experiments that demonstrate the strong influence of the thermal conductivity of the substrate on the evaporation of a pinned droplet. We show that this behaviour can be captured by a mathematical model including the variation of the saturation concentration with temperature, and hence coupling the problems for the vapour concentration in the atmosphere and the temperature in the liquid and the substrate. Furthermore, we show that including two ad hoc improvements to the model, namely a Newton's law of cooling on the unwetted surface of the substrate and the buoyancy of water vapour in the atmosphere, give excellent quantitative agreement for all of the combinations of liquid and substrate considered

Altered calcium signaling in cancer cells

It is the nature of the calcium signal, as determined by the coordinated activity of a suite of calcium channels, pumps, exchangers and binding proteins that ultimately guides a cell's fate. Deregulation of the calcium signal is often deleterious and has been linked to each of the 'cancer hallmarks'. Despite this, we do not yet have a full understanding of the remodeling of the calcium signal associated with cancer. Such an understanding could aid in guiding the development of therapies specifically targeting altered calcium signaling in cancer cells during tumorigenic progression. Findings from some of the studies that have assessed the remodeling of the calcium signal associated with tumorigenesis and/or processes important in invasion and metastasis are presented in this review. The potential of new methodologies is also discussed. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers

Operationalising a metric of nitrogen impacts on biodiversity for the UK response to a data request from the Coordination Centre for Effects

As a signatory party to the Convention on Long Range Transboundary Air Pollution (CLRTAP), the UK has been requested to provide biodiversity metrics for use in assessing impacts of atmospheric nitrogen (N) pollution. Models of soil and vegetation responses to N pollution can predict changes in habitat suitability for many plant and lichen species. Metrics are required to relate changes in a set of species to biodiversity targets. In a previous study, the suitability of the habitat for a set of positive indicator-species was found to be the measure, out of potential outputs from models currently applicable to the UK, which was most clearly related to the assessment methods of habitat specialists at the Statutory Nature Conservation Bodies (SNCBs). This report describes the calculation of values for a metric, based on this principle, for a set of example habitats under different N pollution scenarios. The examples are mainly from Natura-2000 sites, and are defined at EUNIS Level 3 (e.g. F4.1 Wet heath). Values for the biodiversity metric were shown to be greater on all sites in the “Background” scenario than in the scenario with greater N and S pollution, illustrating a positive response of biodiversity to reduced pollution. Results of the study were submitted in response to the ‘Call for Data 2012-14’ by the CLTRAP Co-ordination Centre for Effects (CCE), and presented at the 24th CCE Workshop in April 2014. Metrics calculated on a similar basis were also presented by the Netherlands, Switzerland and Denmark. Such metrics indicate biodiversity status more accurately than other types of metric such as Simpson index or similarity to a reference community, so it was decided to adopt habitat-suitability for positive indicator-species as a common basis for a biodiversity metric in this context. Further work is needed to determine the typical range of metric values in different habitats, and threshold values for damage and recovery. Requirements are likely to be specified in detail in the next CCE Call for Data. The current study shows that a biodiversity metric based on habitat-suitability for positive indicator-species is a useful and responsive method for summarising outputs of models of air pollution impacts on ecosystems

Reactor monitoring and safeguards using antineutrino detectors

Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactors, as part of International Atomic Energy Agency (IAEA) and other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway across the globe.Comment: 6 pages, 4 figures, Proceedings of XXIII International Conference on Neutrino Physics and Astrophysics (Neutrino 2008); v2: minor additions to reference

Shoot growth of woody trees and shrubs is predicted by maximum plant height and associated traits

1. The rate of elongation and thickening of individual branches (shoots) varies across plant species. This variation is important for the outcome of competition and other plant-plant interactions. Here we compared rates of shoot growth across 44 species from tropical, warm temperate, and cool temperate forests of eastern Australia.2. Shoot growth rate was found to correlate with a suite of traits including the potential height of the species, xylem-specific conductivity, leaf size, leaf area per xylem cross-section, twig diameter (at 40 cm length), wood density and modulus of elasticity.3. Within this suite of traits, maximum plant height was the clearest correlate of growth rates, explaining 50 to 67% of the variation in growth overall (p p 4. Growth rates were not strongly correlated with leaf nitrogen or leaf mass per unit leaf area.5. Correlations between growth and maximum height arose both across latitude (47%, p p p p < 0.0001), reflecting intrinsic differences across species and sites

Quantifying Climatic Risk In The Semiarid Tropics: ICRISAT Experience

Troll defined semiarid environments in terms of the average pcriod each year when rainfall (R) exceeded potential evaporation (PE). In the semiarid tropics (SAT), rainfall changes rapidly at the beginning and end of the monsoon so that thc pcriod whcn K > PE is insensitive to thc arbitrary way PE is dcfincd or mcasurcd. Hargreaves and Robertson used somewhat more sophisticated mcthods to spccify thc length of the growing season in terms of thc pcriod when "dependable' precipitation (i.e. the amount exceeded in at least 75% of years) was more than PE/3. This critcrion was used in early work at ICRISAT. Later, a watcr balance model (WATBAI.) was introduced to cstimatc the risk of crop failure following dry spclls at any time during the monsoon. SORGF was the first simulation met tested at ICRISAT, calibrated with a set of regional data, and then used for risk analysis. Recently, a simplcr simulation modcl (RESCRP) was developed to predict cmp responses to wcathcr and soil water. In this presentation, an even simpler version is described and uscd to estimate yicld probabilities at hvo sites with contrasting rainfall regimes as a function of niaxin~un~ available water or of light interception. Ihe analysis demonstrates thc interaction of weather, soil and plant factors in determining production risks. Many environmental constraints endured by crops and by farmers in thc SAT arc not yet amenable to modelling so that attempts to modcl risk, even with thc most con~plcx simulation models, arc somewhat unrealistic. Major problems not yct adcquatcly addressed by modellers includc germination, seedling establishmcnt and root pcnctration in difficult soils, pests and diseases, and damage caused by wind or vcry heavy rain. Achieving the right balance between productivity and risk lies at thc base of all agricultural development. The SAT is an ecologically fragile region where thc production of food is particularly hazardous bccausc rainfall is erratic, soils arc impoverished, and few fanners are able to control pests and discases cffectivcly or to apply optimal amounts of fertiliser. Because population is growing faster than food supplies in many parts of the SAT, subsistence agriculture has extended into marginal land, damaging the environment and threatening thc long-term viability of economic and social devclopmcnt. In this review, we identify salient environmental fcatures of thc SA'T and considcr briefly some of the ways in which ICRISAT scientists have bccn ablc to rcducc production risks. We then assess progress in climatic analysis and indicalc thc directions in which we believe the modelling of crop production should bc cncouragcd to dcvclop

Assessing the benefits of crop albedo bio-geoengineering

It has been proposed that growing crop varieties with higher canopy albedo would lower summer-time temperatures over North America and Eurasia and provide a partial mitigation of global warming ('bio-geoengineering') (Ridgwell et al 2009 Curr. Biol. 19 1–5). Here, we use a coupled ocean–atmosphere–vegetation model (HadCM3) with prescribed agricultural regions, to investigate to what extent the regional effectiveness of crop albedo bio-geoengineering might be influenced by a progressively warming climate as well as assessing the impacts on regional hydrological cycling and primary productivity. Consistent with previous analysis, we find that the averted warming due to increasing crop canopy albedo by 0.04 is regionally and seasonally specific, with the largest cooling of ~1 °C for Europe in summer whereas in the low latitude monsoonal SE Asian regions of high density cropland, the greatest cooling is experienced in winter. In this study we identify potentially important positive impacts of increasing crop canopy albedo on soil moisture and primary productivity in European cropland regions, due to seasonal increases in precipitation. We also find that the background climate state has an important influence on the predicted regional effectiveness of bio-geoengineering on societally-relevant timescales (ca 100 years). The degree of natural climate variability and its dependence on greenhouse forcing that are evident in our simulations highlights the difficulties faced in the detection and verification of climate mitigation in geoengineering schemes. However, despite the small global impact, regionally focused schemes such as crop albedo bio-geoengineering have detection advantages