Jonathan Watson

The major organic component in carbonaceous meteorites is an organic macromolecular material. The Murchison macromolecular material comprises aromatic units connected by aliphatic and heteroatom-containing linkages or occluded within the wider structure. The macromolecular material source environment remains elusive. Traditionally, attempts to determine source have strived to identify a single environment. Here, we apply a highly efficient hydrogenolysis method to liberate units from the macromolecular material and use mass spectrometric techniques to determine their chemical structures and individual stable carbon isotope ratios. We confirm that the macromolecular material comprises a labile fraction with small aromatic units enriched in (13)C and a refractory fraction made up of large aromatic units depleted in (13)C. Our findings suggest that the macromolecular material may be derived from at least two separate environments. Compound-specific carbon isotope trends for aromatic co...

Morris, Adam; Franchi, Ian; Baker, Lee; Watson, Jonathan and Wright, Ian (2006). Determing the ef-fects of aqueous alteration on the distribution of oxygen isotopes in carbonaceous chondrites. In: 69th Annual Meteoritical Society Meeting, 6-11 August 2006, Zurich, ...

Introduction: Impact events have the potential to generate a number of long-term sources of heat that can lead to the initiation of hydrothermal systems when the impact occurs on a water- or ice- rich target. Such hydrothermal systems have been postulated as promising locations to search for evidence of past biological processes on Mars due to the prevalence of impact cratering as a surface process in Mars's early history (1). In this study, we have used molecular parameters of the thermal maturity of organic matter combined with palynology and carbon isotope stratigraphy to study the post impact thermal history of crater fill sediments from the Boltysh crater, Ukraine. Crater-fill sediments of the Boltysh crater: The Boltysh impact crater, is a 24km diameter complex structure formed on the basement rocks of the Ukrainian shield which has been dated at 65.17±0.64 Ma. The crater was drilled in the 1960s - 1980s but the cores were not curated and have been lost. A 596m cored boreh...

One of the goals of current martian exploration is to search for evidence of extinct (or even extant) life. In recent years, this goal has been interpreted as a search for evidence of water on Mars’ surface. The success of instrumentation (high resolution cameras and infrared spectrometers) on orbiting spacecraft, coupled with in situ data from the MER rovers have revolutionized our understanding of the surface of Mars, the type of rocks and minerals pre-sent, and their stratigraphy [1 and subsequent papers]. It is clear that there has been extensive and intensive aqueous action at different periods in Mars’ history, and evidence for water is, to all intents and purposes, irrefutable. It is now time to define the next phase in the search for life as a search for regions of habitability on Mars [2]. A search for life could also be seen as a search for carbon, as one of the major assumptions that has been made in the search for life on Mars is that any life present is likely to be car...

... Recommendations for further study are also presented. T13 Amino Acid Racemization at Newcastle MATTHEW COLLINS, DARREL MADDY and KIRSTY PENKMAN ... (Received 12 July 2002) Amino acid racemization as a geochronological tool, remains controversial. ...

ABSTRACT The production of gaseous sulfur-containing species during the steam-assisted recovery of heavy oil and bitumen presents problems owing to their toxicity, corrosion properties and odor. In order to quantitatively study aquathermolysis sulfur chemistry during the thermal (steam-assisted) recovery of heavy oils we have subjected a well-characterized and sulfur-rich bitumen core sample to 150 - 325°C and 70 - 1740 psia (0.48 - 12 MPa) conditions in the continued presence of liquid water for 24 hours. The reaction products include gases, oil flotate, oil sinkate, water-soluble products, and water- insoluble residues. All have been studied with a variety of analytical techniques, including FTIR spectroscopy, chromatographic fractionation (SARA analysis), GC-FPD and GC-MS. Moreover, these techniques have been extended to analysis of the asphaltene fractions. Results suggest that some in-situ upgrading of the oil occurs under these conditions; additionally, gaseous hydrogen sulfide is released at temperatures at and above 250 °C. Variations in the relative abundances of solubility classes and chemical fractions imply that the source of sulfur is via the thermal degradation of resins and/or asphaltenes. The experimental methods, results and quantification approach discussed herein will be useful to support the development of models for engineering design of facilities for the steam-assisted recovery of heavy oils and bitumen.

Subcritical water extraction of organic matter containing sedimentary rocks at 300°C and 1500psi produces extracts comparable to conventional solvent extraction. Subcritical water extraction of previously solvent extracted samples confirms that high molecular weight organic matter (kerogen) degradation is not occurring and that only low molecular weight organic matter (free compounds) are being accessed in analogy to solvent extraction procedures. The sedimentary rocks chosen for extraction span the classic geochemical organic matter types. A type I organic matter-containing sedimentary rock produces n-alkanes and isoprenoidal hydrocarbons at 300°C and 1500psi that indicate an algal source for the organic matter. Extraction of a rock containing type II organic matter at the same temperature and pressure produces aliphatic hydrocarbons but also aromatic compounds reflecting the increased contributions from terrestrial organic matter in this sample. A type III organic matter-containing sample produces a range of non-polar and polar compounds including polycyclic aromatic hydrocarbons and oxygenated aromatic compounds at 300°C and 1500psi reflecting a dominantly terrestrial origin for the organic materials. Although extraction at 300°C and 1500psi produces extracts that are comparable to solvent extraction, lower temperature steps display differences related to organic solubility. The type I organic matter produces no products below 300°C and 1500psi, reflecting its dominantly aliphatic character, while type II and type III organic matter contribute some polar components to the lower temperature steps, reflecting the chemical heterogeneity of their organic inventory. The separation of polar and non-polar organic compounds by using different temperatures provides the potential for selective extraction that may obviate the need for subsequent preparative chromatography steps. Our results indicate that subcritical water extraction can act as a suitable replacement for conventional solvent extraction of sedimentary rocks, but can also be used for any organic matter containing mineral matrix, including soils and recent sediments, and has the added benefit of tailored extraction for analytes of specific polarities.

ABSTRACT In this paper, we report presence of various organic products formed in a flowing atmospheric glow discharge fed by gas mixture containing 1-5 % of methane in nitrogen, which mimics the Titan's atmosphere. Gaseous products from the discharge exhaust were analysed by Gas Chromatography with Mass Spectrometry (GC-MS). The experimental results revealed C2H2, HCN, and CH3CN as the major products. Various hydrocarbons and nitriles were the other determined gaseous products. Whilst many of these compounds have been predicted and/or observed in the Titan atmosphere, the present plasma experiments provide evidence of both the chemical complexity of Titan atmospheric processes and the mechanisms by which larger species grow prior to form the dust that should cover much of the Titan's surface. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The majority of global petroleum is in the form of highly viscous heavy oil. Traditionally heavy oil in sands at shallow depths is accessed by large scale mining activities. Recently steam has been used to allow heavy oil extraction with greatly reduced surface disturbance. However, in situ thermal recovery processes can generate hydrogen sulphide, high levels of which are toxic to humans and corrosive to equipment. Avoiding hydrogen sulphide production is the best possible mitigation strategy. Here we use laboratory aquathermolysis to reproduce conditions that may be experienced during thermal extraction. The results indicate that hydrogen sulphide generation occurs within a specific temperature and pressure window and corresponds to chemical and physical changes in the oil. Asphaltenes are identified as the major source of sulphur. Our findings reveal that for high sulphur heavy oils, the generation of hydrogen sulphide during steam assisted thermal recovery is minimal if temperat...

The search for in situ organic matter on Mars involves encounters with minerals and requires an understanding of their influence on lander and rover experiments. Inorganic host materials can be helpful by aiding the preservation of organic compounds or unhelpful by causing the destruction of organic matter during thermal extraction steps. Perchlorates are recognized as confounding minerals for thermal degradation studies. On heating, perchlorates can decompose to produce oxygen, which then oxidizes organic matter. Other common minerals on Mars, such as sulfates, may also produce oxygen upon thermal decay, presenting an additional complication. Different sulfate species decompose within a large range of temperatures. We performed a series of experiments on a sample containing the ferric sulfate jarosite. The sulfate ions within jarosite break down from 500°C. Carbon dioxide detected during heating of the sample was attributed to oxidation of organic matter. A laboratory standard of f...

Patellar tendinopathy is a common condition. There are a wide variety of treatment options available, the majority of which are nonoperative. No consensus exists on the optimal method of treatment. PubMed spanning 1962-2014. Clinical review. Level 4. The majority of cases resolve with nonoperative therapy: rest, physical therapy with eccentric exercises, cryotherapy, anti-inflammatories, corticosteroid injections, extracorporeal shockwave therapy, glyceryl trinitrate, platelet-rich plasma injections, and ultrasound-guided sclerosis. Refractory cases may require either open or arthroscopic debridement of the patellar tendon. Corticosteroid injections provide short-term pain relief but increase risk of tendon rupture. Anti-inflammatories and injectable agents have shown mixed results. Surgical treatment is effective in many refractory cases unresponsive to nonoperative modalities. Physical therapy with an eccentric exercise program is the mainstay of treatment for patellar tendinopath...

ABSTRACT The use of high-speed penetrator deployment technologies may offer the first opportunity to perform in-situ surface and subsurface analysis of Europan material. In order that such a unique opportunity returns the maximum scientific return, careful consideration to the instrument payload will be required. Gas chromatography-mass spectrometry (GC-MS) is the gold standard in the analytical technique for the determination of the molecular and elemental composition. The current state of the art in light element and organic molecule detection is the 500 gram GC-MS Ptolemy instrument onboard the ROSETTA lander Philae. We believe that Ptolemy style science capabilities are imperative for any penetrator mission to Europa (or Ganymede) as these would allow for the full characterisation of the organic inventory and the detection of any compounds of biological significance at the penetrator impact sites. In addition, through isotopic composition analysis it may be possible to further constrain the origin of any detected compounds, enable the detection of biogenic signatures (i.e. through measurement of delta 34S) and allow the distinction between meteoric origin and local production of organic material. We will present the status of rugged instrumentation currently under development that will allow these scientific objectives to be met and thus enable Ptolemy style science to be conducted from a penetrator deployed scientific platform.

... Interventions must take into account the varying needs of these groups. Coherent and integrated approaches are required for different settings and different target groups, within a 'community-wide' context, based on clearly defined and realistic aims and objectives. ...

To report a case series of failures of bioabsorbable interference screws with possible identification of a novel failure mechanism. A retrospective review of ACL reconstructions by the senior author utilizing BioComposite™ Interference Screws (Arthrex, Inc., Naples, FL) was performed. Complications related to screw placement, including fracture, breakage or bending were examined. Our rate and methods of failure were compared to those quoted in the current literature. Eighty-seven patients of average age 23.8years met inclusion criteria. There were eight screw failures in six patients, with femoral failure in seven and tibial failure in one. The femoral screw fractured halfway between the tip and head in five, while the head of the screw broke in one and the screw bent in another. In the case of tibial interference screw fracture, failure occurred halfway between the tip and head. The insertion device that was used was replaced after recognition of material deformation and considered...

There is a lack of consensus regarding the optimal surgical approach and fixation method for distal biceps tendon ruptures. The purpose of this study was to conduct a systematic review comparing the results of the various surgical approaches and repair techniques for acute distal biceps tendon ruptures. We searched the MEDLINE, Cochrane, and Embase databases for all published randomized controlled trials, prospective cohort studies, or case series that involved primary repairs of acute distal biceps tendon ruptures with use of a cortical button, intraosseous screws, suture anchors, or bone tunnels for fixation. Exclusion criteria included case reports, cadaveric studies, repairs of partial ruptures, revision repairs, and multiple methods of fixation in the same patient. Statistical analysis was performed with use of the chi-square test. Twenty-two studies met the inclusion criteria. The total number of patients was 494 (498 elbows). The complication rate was 24.5% (122 of 498 elbows...

There has been an increase in minimally invasive surgery for chronic exertional compartment syndrome (CECS), despite the potential for incomplete compartment release and iatrogenic injuries. To our knowledge, no study has examined the effect of the length of fascial release on compartment pressures. The purpose was to explain the high failure rate seen in fascial release for CECS by evaluating the effect of fasciotomy length on intracompartmental pressures. We hypothesized that complete fascial release would need to be performed to return pressures to baseline levels. Controlled laboratory study. Five male swine (10 lower extremities) were anesthetized. A slit catheter, connected to a pressure monitor, was inserted into the anterior compartment and a solution containing 5% swine albumin was injected into the compartment until the compartment pressure was >25 mm Hg for 10 minutes. Pressures were measured at rest, after the injection, and after each 10% incremental fasciotomy relea...

To determine whether reaming of anterior cruciate ligament (ACL) reconstruction tibial tunnels with a 10-mm-diameter reamer would result in injury to the anterior roots of the medial and lateral menisci in an in vitro model when using a tibial aiming device at two settings (40° and 60°). Three-dimensional footprints of the ACL and the anterior roots of the menisci were measured for 12 human cadaveric tibias. Measurements were taken before and after attempted reaming of an ACL tibial reconstruction tunnel in the calculated ACL centre using a tibial aiming device set at two angles (40° and 60°). Iatrogenic injury to the anterior root of the medial meniscus caused by overlap with the reamed tibial tunnel was found in 3/6 specimens in Group 1 (40°) and 0/6 specimens in Group 2 (60°). The average area of iatrogenic injury in Group 1 was 9.6 mm(2) (8.6 % of the root). There was iatrogenic injury to the anterior root of the lateral meniscus in 4/6 specimens for both groups. The average area of iatrogenic injury was 20.5 mm(2) (28.8 %) for Group 1 and 16.2 mm(2) (25.9 %) for Group 2. Reaming of ACL tibial reconstruction tunnels carries a risk of iatrogenic injury to the anterior meniscus roots, even when tunnels are reamed based on guide pin placement in the calculated centre of the ACL. Reaming at varying tibial aiming device angle settings can affect the obliquity of the tunnel aperture and cause iatrogenic injury to the anterior meniscal roots. Caution should be exercised clinically to avoid iatrogenic injury to both the anterior meniscal roots while reaming tibial tunnels during ACL reconstructions.

Hip arthroscopy can be a successful surgery when properly indicated and performed properly. In the setting of dysplasia, arthroscopy of the hip can lead to devastating consequences. This case presents a patient who underwent hip arthroscopy despite having significant hip dysplasia. The surgery failed and was subsequently revised with a concomitant arthroscopic labral repair and periacetabular osteotomy with good results at 2-year follow-up.

The painful neuroma is an often debilitating sequela of nerve injury about the hand. The exact pathophysiology of this condition is poorly understood. After sharp trauma to a peripheral nerve, as nerve ends try to connect with their end organs and "find" the distal nerve stump, fascicular escape and scarring can lead to the development of a painful neuroma. Painful neuromas can even be associated with blunt trauma or retraction of a nerve when the nerve is not actually divided. Green's definition of a neuroma is "the inevitable, unavoidable, and biologic response of the proximal stump after it has been divided in situations where regenerating axons are impeded from re-entering the distal stump."(1) A number of unknown factors make certain patients more susceptible to neuroma formation. In addition, certain nerves such as the superficial radial nerve are more prone to the development of a painful neuroma. Treatment of neuromas of the hand is important because they can be quite debilitating and painful, often preventing patients from continuing with their normal daily activities. There are a number of approaches to the painful neuroma, and the treatment plan must be tailored to the individual patient.

During the biodegradation of crude oil in the laboratory, significant amounts of carboxylic acids were produced. Medium molecular weight (C10–C20) carboxylic acids were rapidly produced, which coincided with the removal of the n-alkanes but these acids were then also rapidly biodegraded. After extensive biodegradation of the hydrocarbons there was an increase in the concentration of higher (>C20) molecular weight branched and cyclic carboxylic acids which appeared as an unresolved complex mixture (UCM) in the gas chromatograms of these acid fractions. These latter acids appeared recalcitrant to further biodegradation during the experiment. The presence of hopanoic acids with the 17α(H),21β(H) configuration in the most degraded laboratory samples, indicated that biodegradation of hopane hydrocarbons had also taken place, with side chain oxidation.

... Bridges, JC; Schwanethal, JP; Paton, MD; Pearson, VK; Greenwood, RC; Watson, JS and Morgan, GH (2004 ... 2004 a former member of staff at the Planetary and Space Sciences Research Institute (PSSRI) of the Open University in Milton Keynes reported a bright fireball at dawn. ...