AGRICULTURAL ANALYSIS BY PLASMA EMISSION SPECTROSCOPY WITH SLURRY ATOMISATION

The three electrode direct current plasma (DCP), has been investigated for the analysis of samples introduced using aqueous solution nebulisation, hydride generation and slurry atomisation. For aqueous solutions, simplex optimisation with signal to background ratio as the criterion of merit, vertical viewing position was found to be most critical. A continuous-flow hydride generator was interfaced to the DCP via a modified sample introduction chimney. Optimisation indicated that total sample introduction gas flow rates were essentially similar to those for conventional nebulisation and that vertical viewing position was again critical. Generation conditions for lead hydride were also simplex optimised. Acid, sodium hydroxide, and hydrogen peroxide concentration were all found to be critical. Detection limits for hydride generation were: As 4 ng cmˉ³, Se 4 ng cmˉ³, Pb 10 ng cmˉ³. Arsenic and selenium were accurately determined in various reference materials. The determination of Mg in aqueous slurries of kaolin was optimised using the Mg(II) 279.079 nm line and conventional sample introduction. Vertical viewing position was again critical with the optimum on the boundary of the analytical zone and over the plasma core. A reduction of emission intensity at high slurry concentrations (> 12%), was observed. Particle size was the most important parameter in slurry atomisation, < 5 µm being preferred. Soils, milk, plant materials and sewage sludges were successfully analysed by slurry atomisation. Where necessary, particle size was reduced using simple grinding procedures. For fibrous materials, prior matrix carbonisation was advantageous. Results obtained using these procedures and simple aqueous calibration showed excellent agreement with certified values of reference materials. Electron number density (ne), excitation temperature (Texc) and ionisation temperature (Tion), were measured for two series of kaolin slurries, (1-20% m/V), one containing 5 g 1ˉ¹ lithium as enhancement buffer. For the slurries containing added lithium, Texc and ne were found to be reduced with increasing slurry concentration. Observed decreases in analyte emission with increased sample loadings (> 12%), are considered to be consistent with proposed excitation models.Agricultural Development Advisory Service, Burghill Road, Westbury-on-Trym, Bristo

Assignment of the Human and Mouse Prion Protein Genes to Homologous Chromosomes

Purified preparations of scrapie prions contain one major macromolecule, designated prion protein (PrP). Genes encoding PrP are found in normal animals and humans but not within the infectious particles. The PrP gene was assigned to human chromosome 20 and the corresponding mouse chromosome 2 using somatic cell hybrids. In situ hybridization studies mapped the human PrP gene to band 20p12→pter. Our results should lead to studies of genetic loci syntenic with the PrP gene, which may play a role in the pathogenesis of prion diseases or other degenerative neurologic disorders

Safety and physiological effects of two different doses of elosulfase alfa in patients with morquio a syndrome: A randomized, double-blind, pilot study.

The primary treatment outcomes of a phase 2, randomized, double-blind, pilot study evaluating safety, physiological, and pharmacological effects of elosulfase alfa in patients with Morquio A syndrome are herewith presented. Patients aged ≥7 years and able to walk ≥200 m in the 6-min walk test (6MWT) were randomized to elosulfase alfa 2.0 or 4.0 mg/kg/week for 27 weeks. The primary objective was to evaluate the safety of both doses. Secondary objectives were to evaluate effects on endurance (6MWT and 3-min stair climb test [3MSCT]), exercise capacity (cardio-pulmonary exercise test [CPET]), respiratory function, muscle strength, cardiac function, pain, and urine keratan sulfate (uKS) levels, and to determine pharmacokinetic parameters. Twenty-five patients were enrolled (15 randomized to 2.0 mg/kg/week and 10 to 4.0 mg/kg/week). No new or unexpected safety signals were observed. After 24 weeks, there were no improvements versus baseline in the 6MWT, yet numerical improvements were seen in the 3MSCT with 4.0 mg/kg/week. uKS and pharmacokinetic data suggested no linear relationship over the 2.0-4.0 mg/kg dose range. Overall, an abnormal exercise capacity (evaluated in 10 and 5 patients in the 2.0 and 4.0 mg/kg/week groups, respectively), impaired muscle strength, and considerable pain were observed at baseline, and there were trends towards improvements in all domains after treatment. In conclusion, preliminary data of this small study in a Morquio A population with relatively good endurance confirmed the acceptable safety profile of elosulfase alfa and showed a trend of increased exercise capacity and muscle strength and decreased pain

Thermal Expansion of Carbamazepine:Systematic Crystallographic Measurements Challenge Quantum Chemical Calculations

We report systematic temperature-dependent X-ray measurements on the most stable carbamazepine polymorph. This active pharmaceutical ingredient is used to demonstrate how the thermal expansion can probe certain intermolecular interactions resulting in anisotropic expansion behavior. We show that most structural features can be captured by electronic structure calculations at the quasi-harmonic approximation (QHA) provided a dispersion-corrected density functional based method is employed. The impact of thermal expansion on the phonon modes and hence free energy contributions is large enough to impact the relative stability of different polymorphs

Sport coaches' experiences of athlete injury : the development and regulation of guilt

This study sought to examine coaches’ stories of guilt in the specific context of athlete injury. Using narrative interviews with a diverse group of ten coaches, guilt was found to be a commonly experienced emotion that the participants also sought to regulate. The coaches’ experiences of the embodiment and management of guilt is primarily, although not exclusively, interrogated using the mainstream psychological theorising of Kubany and Watson (2003). The article concludes by connecting the coaches’ experiences of guilt with critiques of the prevailing deontological approach used to define what it means to be a ‘good’ sport coach. Here we suggest that dominant perspectives in coach education may be instrumental in entrenching coaches’ experience of guilt

The search for freedom in extreme sports: A phenomenological exploration

Participation in extreme sports is continuing to grow, yet there is still little understanding of participant motivations in such sports. The purpose of this paper is to report on one aspect of motivation in extreme sports, the search for freedom. The study utilized a hermeneutic phenomenological methodology. Fifteen international extreme sport participants who participated in sports such as BASE jumping, big wave surfing, extreme mountaineering, extreme skiing, rope free climbing and waterfall kayaking were interviewed about their experience of participating in an extreme sport. Results reveal six elements of freedom: freedom from constraints, freedom as movement, freedom as letting go of the need for control, freedom as the release of fear, freedom as being at one, and finally freedom as choice and responsibility. The findings reveal that motivations in extreme sport do not simply mirror traditional images of risk taking and adrenaline and that motivations in extreme sports also include an exploration of the ways in which humans seek fundamental human values. © 2013 Elsevier Ltd

Past and present bacterial communities in deglaciating northern latitude catchments reveal varied soil carbon sequestration potential

Glacier retreat in northern latitudes exposes new landscapes that may develop soils and ecosystems, which in turn may sequester carbon and serve as a negative climate change feedback. Proglacial soil development and landscape evolution were investigated using transects from three high-latitude glacial systems (Tarfala, Sweden; Vatnajökull, Iceland; Zackenberg, Greenland). Soil samples were analysed for organic carbon (OC) concentration, bacteriohopanepolyol biomarkers (BHPs, membrane lipids that trace major microbial groups), and 16S rRNA gene sequencing. Soil and sediment samples from Sweden showed lower OC concentrations (0.27 ± 0.26 wt%) than deposits from Iceland (1.59 ± 2.12 wt%) and Greenland (1.62 ± 1.54 wt%). Highest OC concentrations were from moraines exposed for several millennia, while recently deglaciated areas in Sweden and Iceland had the lowest OC values. Higher fractional abundance of soil-specific BHPs down-valley (up to 30 % in Greenland), and matching increases in the R'soil index (up to 0.37 in Greenland), suggest soils are gradually developing in recently deglaciated areas, with a stable soil microbial community observed in some soils from Iceland and Greenland. Microbial communities stabilized quickly, adapting to the new environment. Acidobacteria, Actinobacteria, Chloroflexi, Proteobacteria, Planctomycetes, and Verrucomicrobia were the most relatively abundant phyla identified in deglaciated areas, while candidate phylum Dormibacteraeota had high concentrations in samples from Sweden. Linking organic biomarkers with bacterial communities suggests that soil-marker BHPs were produced by Rhodospirillaceae and may have been produced by Bradyrhizobiaceae and Hyphomicrobiaceae. However, despite some similarities in microbial communities, differences in soil development suggest that the evolution of deglaciating landscapes and their impact on the global carbon cycle may vary substantially.</p

The Role of Tacit Knowledge in Developing Networks for Sustainable Agriculture

Whilst objectivist epistemologies have been dominant in productivist agriculture, the local, cultural and environmental contexts of sustainable agriculture are more fully informed by constructivist epistemologies. Within constructivism, tacit knowledge - an intuitive knowledge that cannot be formalised - is explored empirically. Six types of tacit knowledge were identified as a result of working closely with a sustainable food network: the Brighton and Hove Food Partnership. Customs cohere around integrating food with other sustainable activity; developing a complex unregulated organisation requires savoir-faire. The unique character of Brighton has developed an operational folklore, and network identity is important, particularly in relation to conventional agriculture and to the city as a whole. A confidence in people's roles has helped define network development and using different discourses, communicating the network in diverse contexts, is important for understanding the network. All these tacit knowledge elements have a strong influence over the network but have to be assimilated knowledge rather than learned