Determination of gas volume trapped in a closed fluid system

Technique involves extracting known volume of fluid and measuring system before and after extraction, volume of entrapped gas is then computed. Formula derived from ideal gas laws is basis of this method. Technique is applicable to thermodynamic cycles and hydraulic systems

Frontier exploration and the North Atlantic Igneous Province : new insights from a 2.6 km offshore volcanic sequence in the NE Faroe–Shetland Basin

Acknowledgements and Funding This work was funded by Chevron. The authors would like to acknowledge the Chevron West of Shetlands team along with the Joint Venture partners OMV, Faroe Petroleum and Indemitsu for access to data along with permission to publish this study. PGS is thanked for access to the Corona Ridge Regional Geostreamer (CRRG) data and permission to publish the seismic line. The paper was improved thanks to insightful reviews by S. M. Jones and A. Saunders, which substantially improved an earlier draft. J. Still and F. Thompson gave invaluable technical support at the University of Aberdeen, and K. Wall helped with real-time cuttings analysis.Peer reviewedPostprin

Organic geochemistry of the crater-fill sediments from Boltysh impact crater, Ukraine

The Boltysh impact crater, is a complex structure formed on the basement rocks of the Ukrainian shield which has been dated at 65.17±0.64 Ma [1]. The Boltysh crater has been know for several decades and was originally drilled in the 1960s-1980s in a study of economic oil shale deposits. Unfortunately, the cores were not curated and have been lost. However we have recently re-drilled the impact crater and have recovered a near continuous record of ~400 m of organic rich sediments deposited in a deep isolated lake which overlie the basement rocks spanning a period ~10 Ma. At 24km diameter, Boltysh will not have contributed substantially to the worldwide devastation at the end of the Cretaceous. However, the precise age of the Boltysh impact relative to the Chicxulub impact and its location on a stable low lying coastal plain which allowed formation of the postimpact crater lake make it a particularly important locality. After the impact, the crater quickly filled with water in a short marine phase but returned to fresh water which persisted for >10Ma [2]. These strata contain a valuable record of Paleogene environmental change in central Europe, and one of very few terrestrial records of the KT event. This pre-eminent record of the Paleogene can help us to answer several related scientific questions including the relative age of Boltysh compared with Chicxulub, recovery from the impact, and later climate signals. The organic geochemistry and playnology indicate main inputs to be algal and higher plant within most of the core although there are some marked changes in inputs in some sections. A number of carbon isotope excursions are also present within the core which are currently being further investigated

Tethered Ru(II) catalysts containing a Ru–I bond

Two new iodide-containing derivatives of the widely-adopted arene/Ru(II)/TsDPEN catalysts have been prepared and fully characterised, including through X-ray crystallography. They have been evaluated as catalysts for the asymmetric reduction of acetophenone under both transfer (ATH) and pressure hydrogenation (AH) conditions. The iodide-containing complexes are equally efficient in the ATH reaction, but less active in the AH reaction compared to the chloride derivatives

Peak power output in the bench pull is maximised after 4 weeks of specific power training

Maximal power production has been shown to be a differentiating factor between playing levels in many sports and is thus a focus of many strength and conditioning programmes. We sought to evaluate the duration for which a strategy of training with the optimal load (that maximises power output) will be effective in producing improvements in power output in the bench pull. The optimal load that produced the maximum power output in the bench pull was determined for twenty-one male university athletes who were randomly assigned to a group that trained with their optimal load or a load 10% of their one repetition maximum below the optimal load. Both groups completed two sessions per week for 4 weeks, after which their power output capabilities were reassessed. They then trained for a further 3 weeks with a load that was modified to reflect changes in their optimal load. The cohort as a whole had improved their peak power output by 4.6% (p = 0.002, d = 0.290) after 4 weeks of training, but experienced no further increase after another 3 weeks of training. There were no significant differences in the response to training between the two groups. This study suggests that improvements in power output can be realised within a few weeks when training with the optimal load, but training in such a way for a longer duration may be ineffective. Strength and conditioning coaches should consider periodizing power training to maximise gains in power output capabilities

Accretion Discs in Blazars

The characteristic properties of blazars (rapid variability, strong polarization, high brightness) are widely attributed to a powerful relativistic jet oriented close to our line of sight. Despite the spectral energy distributions (SEDs) being strongly jet-dominated, a "big blue bump" has been recently detected in sources known as flat spectrum radio quasars (FSRQs). These new data provide a unique opportunity to observationally test coupled jet-disc accretion models in these extreme sources. In particular, as energy and angular momentum can be extracted by a jet magnetically coupled to the accretion disc, the thermal disc emission spectrum may be modified from that predicted by the standard model for disc accretion. We compare the theoretically predicted jet-modified accretion disc spectra against the new observations of the "big blue bump" in FSRQs. We find mass accretion rates that are higher, typically by a factor of two, than predicted by standard accretion disc theory. Furthermore, our results predict that the high redshift blazars PKS 0836+710, PKS 2149-307, B2 0743+25 and PKS 0537-286 may be predominantly powered by a low or moderate spin (a < 0.6) black hole with high mass accretion rates mdot_a ~ 50 - 200 msol/yr, while 3C 273 harbours a rapidly spinning black hole (a = 0.97) with mdot_a ~ 20 msol/yr. We also find that the black hole masses in these high redshift sources must be > 5 * 10^9 msol.Comment: Accepted for publication (17 August 2009) in MNRA

Direct formation of tethered Ru(II) catalysts using arene exchange

An ‘arene exchange’ approach has been successfully applied for the first time to the synthesis of Ru(II)-based ‘tethered’ reduction catalysts directly from their ligands in one step. This provides an alternative method for the formation of known complexes, and a route to a series of novel complexes. The novel complexes are highly active in both asymmetric transfer and pressure hydrogenation of ketones

The domestication of the probiotic bacterium Lactobacillus acidophilus

Lactobacillus acidophilus is a Gram-positive lactic acid bacterium that has had widespread historical use in the dairy industry and more recently as a probiotic. Although L. acidophilus has been designated as safe for human consumption, increasing commercial regulation and clinical demands for probiotic validation has resulted in a need to understand its genetic diversity. By drawing on large, well-characterised collections of lactic acid bacteria, we examined L. acidophilus isolates spanning 92 years and including multiple strains in current commercial use. Analysis of the whole genome sequence data set (34 isolate genomes) demonstrated L. acidophilus was a low diversity, monophyletic species with commercial isolates essentially identical at the sequence level. Our results indicate that commercial use has domesticated L. acidophilus with genetically stable, invariant strains being consumed globally by the human population

Integration of Eye Health into Primary Care Services in Tanzania: A Qualitative Investigation of Experiences in Two Districts.

Background: Visual impairment is a public health problem in sub-Saharan Africa, affecting nearly 5% of the population. Efforts to combat avoidable causes have been hampered by weak health systems and little evidence exists to suggest what interventions may be effective to improve the situation. Despite this, there are calls to promote some specific interventions, one of which being the closer integration of eye health services into health systems, often focusing on training primary health workers to deliver basic eye health services. This study seeks to understand how eye health services are delivered by primary health workers who have received training and what constraints remain to effective service provision. Methods: This was a qualitative investigation into the experiences of 20 primary health workers trained in primary eye care and eight key informants working within specialist eye health services or regional and district health management positions in two districts in Tanzania. Results: Despite feeling confident in their own eye care skills, most primary health workers felt constrained in the services they could provide to their communities by insufficient resources needed for diagnosis and treatment, and by lack of systematic supportive supervision to their work. Specialist ophthalmic staff were aware of this issue, although for the most part they felt it was not within their capacity to remedy and that it fell within the remit of general health managers. Many participants discussed the low support to eye health from the national government, evidenced through the lack of dedicated funding to the area and traditional reliance on outside funds including international charities. Conclusions: Although training of primary health workers is useful, it is recognised that is not sufficient to address the burden of eye health disease present in rural communities in Tanzania. It is likely that broader engagement with the general health system, and most likely with the private sector, will be necessary to improve the coverage of eye health care to remote and poor communities such as those in Morogoro. Further investment is needed to develop innovative approaches to delivering eye health services, including preventative, curative and rehabilitative services

Two large meteorite impacts at the Cretaceous–Paleogene boundary

The end-Cretaceous mass extinction has been attributed by most to a single asteroid impact at Chicxulub on the Yucatán Peninsula, Mexico. The discovery of a second smaller crater with a similar age at Boltysh in the Ukraine has raised the possibility that a shower of asteroids or comets impacted Earth close to the Cretaceous-Paleogene (K-Pg) boundary. Here we present palynological and δ13C evidence from crater-fill sediments in the Boltysh impact crater. Our analyses demonstrate that a post-impact flora, formed on the ejecta layer, was in turn devastated by the K-Pg event. The sequence of floral recovery from the K-Pg event is directly comparable with that in middle North America. We conclude that the Boltysh crater predated Chicxulub by ∼2–5 k.y., a time scale that constrains the likely origin of the bodies that formed the two known K-Pg craters