260 research outputs found
The Birth of PICL: New Laboratory Experiments for Understanding Ocean Worlds
A laboratory set up was built analogous to that of the environment of the Galilean system. Previous work has focused on vapor deposition and shied away from bulk samples which more closely resemble the surface of Europa. The focus of this research has been the relationship between laboratory data to observational spectra collected. Data from various telescopes has given an indication of the species which exist on the surface of Europa. Linear spectral modeling has not been effective in identifying these species due to a lack of viable candidates.
Chapter II focuses on the instrumentation and sample preparation for the laboratory set up. In Chapter III data is presented on the irradiation of sodium chloride at Europa like conditions and the features that arise with cryogenic irradiation. This data is compared to observational data from HST and provides strong evidence for the presences of sodium chloride (NaCl) on Europa's leading hemisphere. Chapter IV presents FTIR and UV/VIS data for the irradiation of sulfate salts suspected to be present on Europa. This presents one of the first instances of cyrogenic electron irradiation of sulfates compared to new data from JWST. Mechanisms for the trapping of carbon dioxide at both Europa and Ganymede have also been investigated. These experiments are paramount for understanding the composition of Europa’s ocean and can be utilized by the Europa Clipper team. Future experiments involving laboratory spectroscopy of carbon dioxide trapping are also highlighted. The use of cyrogenic gamma irradiation experiments and their feasibility are explored
An experimental design approach to the chemical characterisation of pectin polysaccharides extracted from Cucumis melo Inodorus
Extracted pectins have been utilised in a number of applications in both the food and pharmaceutical industries where they are generally used as gelling agents, thickeners and stabilisers, although a number of pectins have been shown to be bioactive. These functional properties will depend upon extraction conditions.
A statistical experimental design approach was used to study the effects of extraction conditions pH, time and temperature on pectins extracted from Cucumis melo Inodorus.
The results show that the chemical composition is very sensitive to these conditions and that this has a great influence on for example the degree of branching. Higher temperatures, lower pHs and longer extraction times lead to a loss of the more acid labile arabinofuranose residues present on the pectin side chain. The fitting of regression equations relating yield and composition to extraction conditions can therefore lead to tailor-made pectins for specific properties and/ or applications
Development of a Multi-technique Characterization Portfolio for Stainless Steels Exposed to Magnox Reprocessing Liquors
Illegal killing associated with gamebird management accounts for up to three-quarters of annual mortality in Hen Harriers Circus cyaneus
Seasonal, synoptic, and diurnal-scale variability of biogeochemical trace gases and O2 from a 300-m tall tower in central Siberia
We present first results from 19 months of semicontinuous concentration measurements of biogeochemical trace gases (CO2, CO, and CH4) and O2, measured at the Zotino Tall Tower Observatory (ZOTTO) in the boreal forest of central Siberia. We estimated CO2 and O2 seasonal cycle amplitudes of 26.6 ppm and 134 per meg, respectively. An observed west-east gradient of about -7 ppm (in July 2006) between Shetland Islands, Scotland, and ZOTTO reflects summertime continental uptake of CO2 and is consistent with regional modeling studies. We found the oceanic component of the O2 seasonal amplitude (Atmospheric Potential Oxygen, or APO) to be 51 per meg, significantly smaller than the 95 per meg observed at Shetlands, illustrating a strong attenuation of the oceanic O2 signal in the continental interior. Comparison with the Tracer Model 3 (TM3) atmospheric transport model showed good agreement with the observed phasing and seasonal amplitude in CO2; however, the model exhibited greater O2 (43 per meg, 32%) and smaller APO (9 per meg, 18%) amplitudes. This seeming inconsistency in model comparisons between O2 and APO appears to be the result of phasing differences in land and ocean signals observed at ZOTTO, where ocean signals have a significant lag. In the first 2 months of measurements on the fully constructed tower (November and December 2006), we observed several events with clear vertical concentration gradients in all measured species except CO. During “cold events” (below -30°C) in November 2006, we observed large vertical gradients in CO2 (up to 22 ppm), suggesting a strong local source. The same pattern was observed in CH4 concentrations for the same events. Diurnal vertical CO2 gradients in April to May 2007 gave estimates for average nighttime respiration fluxes of 0.04 ± 0.02 mol C m-2 d-1, consistent with earlier eddy covariance measurements in 1999–2000 in the vicinity of the tower
Phenotypic variability within the desminopathies: A case series of three patients
The DES gene encodes desmin, a key intermediate filament of skeletal, cardiac and smooth muscle. Pathogenic DES variants produce a range of skeletal and cardiac muscle disorders collectively known as the desminopathies. We report three desminopathy cases which highlight the phenotypic heterogeneity of this disorder and discuss various factors that may contribute to the clinical differences seen between patients with different desmin variants and also between family members with the same variant
Reduced emissions from deforestation and forest degradation (REDD): a climate change mitigation strategy on a critical track
<p>Abstract</p> <p>Background</p> <p>Following recent discussions, there is hope that a mechanism for reduction of emissions from deforestation and forest degradation (REDD) will be agreed by the Parties of the UNFCCC at their 15th meeting in Copenhagen in 2009 as an eligible action to prevent climate changes and global warming in post-2012 commitment periods. Countries introducing a REDD-regime in order to generate benefits need to implement sound monitoring and reporting systems and specify the associated uncertainties. The principle of conservativeness addresses the problem of estimation errors and requests the reporting of reliable minimum estimates (RME). Here the potential to generate benefits from applying a REDD-regime is proposed with reference to sampling and non-sampling errors that influence the reliability of estimated activity data and emission factors.</p> <p>Results</p> <p>A framework for calculating carbon benefits by including assessment errors is developed. Theoretical, sample based considerations as well as a simulation study for five selected countries with low to high deforestation and degradation rates show that even small assessment errors (5% and less) may outweigh successful efforts to reduce deforestation and degradation.</p> <p>Conclusion</p> <p>The generation of benefits from REDD is possible only in situations where assessment errors are carefully controlled.</p
An early Eocene carbon cycle perturbation at ∼52.5 Ma in the Southern Alps: Chronology and biotic response
Referral outcomes of individuals identified at high risk of cardiovascular disease by community health workers in Bangladesh, Guatemala, Mexico, and South Africa
We have found that community health workers (CHWs) with appropriate training are able to
accurately identify people at high cardiovascular disease (CVD) risk in the community who would benefit from
the introduction of preventative management, in Bangladesh, Guatemala, Mexico, and South Africa. This
paper examines the attendance pattern for those individuals who were so identified and referred to a health care
facility for further assessment and management. Patient records from the health centres in each site were reviewed for data on diagnoses made and
treatment commenced. Reasons for non-attendance were sought from participants who had not attended
after being referred. Qualitative data were collected from study coordinators regarding their experiences
in obtaining the records and conducting the record reviews. The perspectives of CHWs and community
members, who were screened, were also obtained
- …