Components and processes affecting producibility and commerciality of shale resource systems

Unconventional shale resource systems have provided North America with abundant energy supplies and reserves for present and future decades. This energy resource was largely overlooked until the new millennium. Prior 2000 only a few small oil and gas companies were pursuing such plays led by independent, Mitchell Energy and Development Corporation of The Woodlands, TX. Mitchell's successful commercial development of the Mississippian Barnett Shale of the Ft. Worth Basin, Texas spawned an energy renaissance in North America. In the last decade the development of unconventional shale resource systems has been phenomenal in the United States with abundant new supplies of natural gas and oil. These resource systems are all associated with petroleum source rocks, either within the source rock itself or in juxtaposed, non-source rock intervals. Three key characteristics of these rocks, apart from being associated with organic-rich intervals, are their low porosity (less than 15%), ultra-low permeability (<0.1mD), and brittle or non-ductile nature. These characteristics play a role in the storage, retention, and the requirement of high-energy stimulation to obtain petroleum fl ow. Organic richness and hydrogen content certainly play a role in petroleum generation, but they also play a role in retention and expulsion fractionation of generated petroleum. Often a substantial portion of the porosity evolves from the decomposition of organic carbon that creates organoporosity in addition to any matrix porosity. Open fracture-related porosity is seldom important. Hybrid systems, i.e., organic-lean intervals overlying, interbedded, or underlying the petroleum source rock, are the best producing shale resource systems, particularly for oil due to their limited adsorptive affi nities and the retention of polar constituents of petroleum in the source rock. Paradoxically, the best shale gas systems are those where the bulk of the retained oil in the source rock has been converted to gas by cracking. Such conversion cracks the retained polar constituents of petroleum as well as saturated and aromatic hydrocarbons to condensate-wet gas or dry gas at high thermal maturity. Such high level conversion also creates the maximum organoporosity, while enhancing pore pressure. Bitumen (petroleum)-free total organic carbon (TOC) is comprised of two components, a generative and a non-generative portion. The generative organic carbon (GOC) represents the portion of organic carbon that can be converted to petroleum, whereas the non-generative portion does not yield any commercial amounts of petroleum due to its low hydrogen content. Organoporosity is created by the decomposition of the generative organic carbon as recorded in volume percent. In the oil window, this organoporosity is fi lled with petroleum (bitumen, oil and gas) and is diffi cult to identify, whereas in the gas window any retained petroleum has been converted to gas and pyrobitumen making such organoporosity visible under high magnification microscopy. Production decline analysis shows the variable production potential of many North American shale gas and oil systems and their high decline rates. The most productive North American shale gas systems are shown to be the Marcellus and Haynesville shales, whereas the best shale oil systems are the hybrid Bakken and Eagle Ford systems

Low-temperature gas from marine shales

Thermal cracking of kerogens and bitumens is widely accepted as the major source of natural gas (thermal gas). Decomposition is believed to occur at high temperatures, between 100 and 200°C in the subsurface and generally above 300°C in the laboratory. Although there are examples of gas deposits possibly generated at lower temperatures, and reports of gas generation over long periods of time at 100°C, robust gas generation below 100°C under ordinary laboratory conditions is unprecedented. Here we report gas generation under anoxic helium flow at temperatures 300° below thermal cracking temperatures. Gas is generated discontinuously, in distinct aperiodic episodes of near equal intensity. In one three-hour episode at 50°C, six percent of the hydrocarbons (kerogen & bitumen) in a Mississippian marine shale decomposed to gas (C1–C5). The same shale generated 72% less gas with helium flow containing 10 ppm O2 and the two gases were compositionally distinct. In sequential isothermal heating cycles (~1 hour), nearly five times more gas was generated at 50°C (57.4 μg C1–C5/g rock) than at 350°C by thermal cracking (12 μg C1–C5/g rock)

Effects of neo-adjuvant chemotherapy for oesophago-gastric cancer on neuro-muscular gastric function

Delayed gastric emptying symptoms are often reported after chemotherapy. This study aims to characterise the effects of chemotherapy on gastric neuro-muscular function. Patients undergoing elective surgery for oesophago-gastric cancer were recruited. Acetylcholinesterase, nNOS, ghrelin receptor and motilin expressions were studied in gastric sections from patients receiving no chemotherapy (n = 3) or oesophageal (n = 2) or gastric (n = 2) chemotherapy. A scoring system quantified staining intensity (0–3; no staining to strong). Stomach sections were separately suspended in tissue baths for electrical field stimulation (EFS) and exposure to erythromycin or carbachol; three patients had no chemotherapy; four completed cisplatin-based chemotherapy within 6 weeks prior to surgery. AChE expression was markedly decreased after chemotherapy (scores 2.3 ± 0.7, 0.5 ± 0.2 and 0 ± 0 in non-chemotherapy, oesophageal- and gastric-chemotherapy groups (p < 0.03 each) respectively. Ghrelin receptor and motilin expression tended to increase (ghrelin: 0.7 ± 0.4 vs 2.0 ± 0.4 and 1.2 ± 0.2 respectively; p = 0.04 and p = 0.2; motilin: 0.7 ± 0.5 vs 2.2 ± 0.5 and 2.0 ± 0.7; p = 0.06 and p = 0.16). Maximal contraction to carbachol was 3.7 ± 0.7 g and 1.9 ± 0.8 g (longitudinal muscle) and 3.4 ± 0.4 g and 1.6 ± 0.6 (circular) in non-chemotherapy and chemotherapy tissues respectively (p < 0.05 each). There were loss of AChE and reduction in contractility to carbachol. The tendency for ghrelin receptors to increase suggests an attempt to upregulate compensating systems. Our study offers a mechanism by which chemotherapy markedly alters neuro-muscular gastric function

Opportunities, challenges and concerns for the implementation and uptake of pelvic floor muscle assessment and exercises during the childbearing years: protocol for a critical interpretive synthesis

This is the final version of the article. Available from the publisher via the DOI in this record.BACKGROUND: Pregnancy and childbirth are important risk factors for urinary incontinence (UI) in women. Pelvic floor muscle exercises (PFME) are effective for prevention of UI. Guidelines for the management of UI recommend offering pelvic floor muscle training (PFMT) to women during their first pregnancy as a preventive strategy. The objective of this review is to understand the relationships between individual, professional, inter-professional and organisational opportunities, challenges and concerns that could be essential to maximise the impact of PFMT during childbearing years and to effect the required behaviour change. METHODS: Following systematic searches to identify sources for inclusion, we shall use a critical interpretive synthesis (CIS) approach to produce a conceptual model, mapping the relationships between individual, professional, inter-professional and organisational factors and the implementation, acceptability and uptake of PFME education, assessment and training during the childbearing years. Purposive sampling will be used to identify potentially relevant material relating to topics or areas of interest which emerge as the review progresses. A wide range of empirical and non-empirical sources will be eligible for inclusion to encompass the breadth of relevant individual, professional, inter-professional and organisational issues relating to PFME during childbearing years. Data analysis and synthesis will identify key themes, concepts, connections and relationships between these themes. Findings will be interpreted in relation to existing frameworks of implementation, attitudes and beliefs of individuals and behaviour change. We will collate examples to illustrate relationships expressed in the conceptual model and identify potential links between the model and drivers for change. DISCUSSION: The CIS review findings and resulting conceptual model will illustrate relationships between factors that might affect the implementation, acceptability and uptake of PFME education, assessment and training during the childbearing years. The model will inform the development and evaluation of a training package to support midwives with implementation and delivery of effective PFME during the antenatal period. The review forms part of the first phase of the United Kingdom National Institute for Health Research funded 'Antenatal Preventative Pelvic floor Exercises And Localisation (APPEAL)' programme (grant number: RP-PG-0514-20002) to prevent poor health linked to pregnancy and childbirth-related UI. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: CRD42016042792.The APPEAL project is funded by a National Institute for Health Research (NIHR) programme grant for applied research (RP-PG-0514-20002). MP and SD were supported in their contribution to the development of the research proposal by the NIHR Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula. CM is part-funded by the CLAHRC West Midlands, and DB is part-funded by the CLAHRC South London

'Anyone but England'? Exploring Anti-English Sentiment as Part of Scottish National Identity in Sport.

This article explores the reasons behind the expression of anti-English sentiment by Scots in relation to both sporting and wider social contexts, whilst also considering the impact of migration to England on the attitudes expressed by members of the Scottish diaspora. Drawing upon the conceptual framework of ‘narrative identity’ proposed elsewhere, data was generated through semi-structured interviews which focused upon the ‘ontological’ and ‘public’ narratives of Scottish identity as expressed by Scots living in England. The findings demonstrate the influence of a wide range of personal, social, historical and political factors in highlighting the cleavage between Scotland and England within the context of sport and society, allowing for a more nuanced understanding of the complex relationship between these two nations in the context of sporting rivalry. This relationship is argued to be heavily influenced by the existence of an ‘underdog mentality’-style grand ‘public narrative’ for Scots in relation to their English neighbours, based on perceived differences in economic and sporting resources between the two countries. This ‘underdog mentality’ therefore acts as a legitimating force for the expression of anti-English sentiment in both a sporting and wider social context as part of some individuals’ ‘ontological narrative’, although the extent of such sentiment was found to vary significantly between individuals and contrasting contexts

Sport, social change and the public intellectual

This article argues that the role of the public intellectual in sport is desperately needed. The research for the article draws upon key interviews and newspaper reports. The paper examines three questions: (i) What is the role of the public intellectual in sport? (ii) Do we wish to encourage the role of the public intellectual in sport? (iii) How does one balance the objective of challenging unseen silences in sport with its potential transformative capacity to produce change (or at least be a resource for hope) in many communities. The challenge is for today’s sociologists of sport and others not to accept the narrow job description of the academic but instead to ensure that the social study of sport is one of these very public, visible forms of activity and engagement

Towards resolving the phosphorus chaos created by food systems

© 2019, The Author(s). The chaotic distribution and dispersal of phosphorus (P) used in food systems (defined here as disorderly disruptions to the P cycle) is harming our environment beyond acceptable limits. An analysis of P stores and flows across Europe in 2005 showed that high fertiliser P inputs relative to productive outputs was driving low system P efficiency (38 % overall). Regional P imbalance (P surplus) and system P losses were highly correlated to total system P inputs and animal densities, causing unnecessary P accumulation in soils and rivers. Reducing regional P surpluses to zero increased system P efficiency (+ 16 %) and decreased total P losses by 35 %, but required a reduction in system P inputs of ca. 40 %, largely as fertiliser. We discuss transdisciplinary and transformative solutions that tackle the P chaos by collective stakeholder actions across the entire food value chain. Lowering system P demand and better regional governance of P resources appear necessary for more efficient and sustainable food systems

Sport for Yes? The role of sporting issues in pro-independence political discourse during the Scottish independence referendum campaign

This article critically considers the extent to which sporting issues were harnessed by pro-independence political campaigners during the Scottish independence referendum campaign. Developments such as the inclusion of sport within the Scottish Government’s White Paper on Scottish independence, the establishment of the ‘Working Group on Scottish Sport’ and the establishment of the ‘Sport for Yes’ campaign group demonstrate the harnessing of sporting issues as an additional, if somewhat peripheral, debate point in the referendum campaigns (Lafferty 2014, Scottish Government 2013, Working Group on Scottish Sport and Scottish Government 2013, 2014). The latter of these developments, the establishment of the ‘Sport for Yes’ campaign group, is of particular interest, offering evidence of the explicit political mobilisation of past and present athletes in support of the ‘Yes Scotland’ pro-independence campaign. The use of sport within pro-independence political discourse is therefore scrutinised, drawing upon the principles of critical discourse analysis to explore the ideological assumptions underpinning the discursive representation of sport in relation to Scottish independence

Coupling high-frequency stream metabolism and nutrient monitoring to explore biogeochemical controls on downstream nitrate delivery

Instream biogeochemical process measurements are often short-term and localized. Here we use in situ sensors to quantify the net effects of biogeochemical processes on seasonal patterns in baseflow nitrate retention at the river-reach scale. Dual-station high-frequency in situ nitrate measurements, were coupled with high-frequency measurements of stream metabolism and dissolved inorganic carbon, in a tributary of the Buffalo National River, Arkansas. Nitrate assimilation was calculated from net primary production, and combined with mass-balance measurements, to estimate net nitrification and denitrification. The combined net effects of these instream processes (assimilation, denitrification, and nitrification) removed >30–90% of the baseflow nitrate load along a 6.5 km reach. Assimilation of nitrate by photoautotrophs during spring and early summer was buffered by net nitrification. Net nitrification peaked during the spring. After midsummer, there was a pronounced switch from assimilatory nitrate uptake to denitrification. There was clear synchronicity between the switch from nitrate assimilation to denitrification, a reduction in river baseflows, and a shift in stream metabolism from autotrophy to heterotrophy. The results show how instream nitrate retention and downstream delivery is driven by seasonal shifts in metabolic pathways; and how continuous in situ stream sensor networks offer new opportunities for quantifying the role of stream biota in the dynamics, fate, and transport of nitrogen in fluvial systems