187 research outputs found
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Marcellus Shale BEG Natural Fracture Project Final Report
Operators in the Marcellus Shale gas play are aware of the importance of natural fractures, and there has been substantial work on the fracture systems in core and outcrop in the large region covered by this play (Eastern Shale Gas Project reports; Evans, 1980, 1994, 1995; Engelder et al., 2009 and references therein; Lash and Engelder, 2005, 2007, 2009). The most common fractures documented by these authors in core and outcrop are subvertical opening-mode fractures that are broadly strike parallel (J1) or cross-fold joints (J2). Evans (1995) also found strike-parallel veins that post-date the J2 set, and Lash and Engelder (2005) describe bitumen-filled microcracks developed during catagenesis. Gale and Holder (2010) found in a study of several gas-shales that narrow, sealed, subvertical fractures are typically present in most shale cores. In shale-gas plays that are produced using hydraulic fracturing stimulation, these fractures are nevertheless important because of their interaction with hydraulic treatment fractures (Gale et al., 2007). At the scale of hydraulic fracture stimulation, natural fracture patterns and in situ stress can be highly variable, even though a broad tectonic pattern may be consistent over hundreds of miles. Thus, site-specific evaluation of the natural fractures and in situ stress is necessary. Open fractures are observed in a few cases in core. Fracture-size scaling, coupled with a fracture-size control over sealing cementation and a subcritical growth mechanism that favors clustering, suggests that open fractures are likely to be concentrated in clusters spaced hundreds of feet apart (Gale, 2002; Gale et al., 2007). Our goal for this project is to characterize the fractures and identify the characteristic spatial arrangement of fractures, including potential clusters of large fractures.
Our emphasis is on characterizing, quantifying, and modeling fractures that have grown in the subsurface in a chemically reactive environment through a combination of observation at a range of scales, detailed petrographic and microstructural observation of cement fills, and geomechanical modeling (cf. Marrett et al., 1999; Gale, 2002; Laubach 1997, 2003; Olson, 2004). Large natural fractures, open or sealed, are typically sparsely sampled in core or image logs. Yet these are the fractures that would have the most effect in augmenting gas flow or influencing the growth of hydraulic fractures. Our approach overcomes the sampling problem by use of fracture size and spatial scaling analysis coupled with geomechanical modeling. That is, we may make predictions about their attributes without sampling them.
Fracture morphology, orientation, spatial organization, and cementation were analyzed using datasets from the project well-experiment area in SW Pennsylvania. We added a dataset from a field area to evaluate the use of outcrop fracture data in reservoir characterization in the Marcellus, thus expanding the relevance of the study beyond the well-experiment area in SW Pennsylvania.Bureau of Economic Geolog
Adult nurse turnover and retention : South London project report
This project was commissioned by Health Education South London (HESL) in response to the workforce planning process for 2014/15 indicating an unprecedented increase in demand for adult nurses in NHS Trusts. The focus of the project was to identify issues and interventions to improve retention of adult nurses and reduce the rate of leaving jobs (turnover). During 2015 the work of the project has included: a systematic literature review to examine evidence of determinants, costs and interventions of adult nurse turnover; analysis of adult nurse workforce data to identify trends and rates in sub-groups of nurses and by characteristics of their employment context; interviews with senior nurse and human resource managers across South London for views and examples of initiatives to reduce turnover; interviews with adult nurses and nurse managers managers as to their views on the issues and initiatives that might help retain nurses. The evidence from each element is presented and then synthesised
A CD-based courseware package for the teaching and consolidating of geological field skills
This article explores a CD-based courseware package for the teaching and consolidating of geological field skills used for the interpretation of folding sequences in deformed rocks, focusing on examples from Anglesey in North Wales. The article briefly considers the advantages and disadvantages of virtual field work and then discusses the rationale, structure, development and production of the CD-ROM courseware package
Developmental Research in Space: Predicting Adult Neurobehavioral Phenotypes via Metabolomic Imaging
As human habitation and eventual colonization of space becomes an inevitable reality, there is a necessity to understand how organisms develop over the life span in the space environment. Microgravity, altered CO2, radiation and psychological stress are some of the key factors that could affect mammalian reproduction and development in space, however there is a paucity of information on this topic. Here we combine early (neonatal) in vivo spectroscopic imaging with an adult emotionality assay following a common obstetric complication (prenatal asphyxia) likely to occur during gestation in space. The neural metabolome is sensitive to alteration by degenerative changes and developmental disorders, thus we hypothesized that that early neonatal neurometabolite profiles can predict adult response to novelty. Late gestation fetal rats were exposed to moderate asphyxia by occluding the blood supply feeding one of the rats pair uterine horns for 15min. Blood supply to the opposite horn was not occluded (within-litter cesarean control). Further comparisons were made with vaginal (natural) birth controls. In one-week old neonates, we measured neurometabolites in three brain areas (i.e., striatum, prefrontal cortex, and hippocampus). Adult perinatally-asphyxiated offspring exhibited greater anxiety-like behavioral phenotypes (as measured the composite neurobehavioral assay involving open field activity, responses to novel object, quantification of fecal droppings, and resident-intruder tests of social behavior). Further, early neurometabolite profiles predicted adult responses. Non-invasive MRS screening of mammalian offspring is likely to advance ground-based space analogue studies informing mammalian reproduction in space, and achieving high-priority multigenerational research that will enable studies of the first truly space-developed mammals
Single-nucleus multi-omics of human stem cell-derived islets identifies deficiencies in lineage specification
Insulin-producing β cells created from human pluripotent stem cells have potential as a therapy for insulin-dependent diabetes, but human pluripotent stem cell-derived islets (SC-islets) still differ from their in vivo counterparts. To better understand the state of cell types within SC-islets and identify lineage specification deficiencies, we used single-nucleus multi-omic sequencing to analyse chromatin accessibility and transcriptional profiles of SC-islets and primary human islets. Here we provide an analysis that enabled the derivation of gene lists and activity for identifying each SC-islet cell type compared with primary islets. Within SC-islets, we found that the difference between β cells and awry enterochromaffin-like cells is a gradient of cell states rather than a stark difference in identity. Furthermore, transplantation of SC-islets in vivo improved cellular identities overtime, while long-term in vitro culture did not. Collectively, our results highlight the importance of chromatin and transcriptional landscapes during islet cell specification and maturation
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Reviving Abandoned Reservoirs With High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir
The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plant that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration are being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the US
Surrogate Markers of Cardiovascular Risk and Chronic Obstructive Pulmonary Disease: A Large Case-Controlled Study.
Cardiovascular disease is a common comorbidity and cause of mortality in chronic obstructive pulmonary disease. A better understanding of mechanisms of cardiovascular risk in chronic obstructive pulmonary disease patients is needed to improve clinical outcomes. We hypothesized that such patients have increased arterial stiffness, wave reflections, and subclinical atherosclerosis compared with controls and that these findings would be independent of smoking status and other confounding factors. A total of 458 patients with a diagnosis of chronic obstructive pulmonary disease and 1657 controls (43% were current or ex-smokers) with no airflow limitation were matched for age, sex, and body mass index. All individuals underwent assessments of carotid-femoral (aortic) pulse wave velocity, augmentation index, and carotid intima-media thickness. The mean age of the cohort was 67±8 years and 58% were men. Patients with chronic obstructive pulmonary disease had increased aortic pulse wave velocity (9.95±2.54 versus 9.27±2.41 m/s; P<0.001), augmentation index (28±10% versus 25±10%; P<0.001), and carotid intima-media thickness (0.83±0.19 versus 0.74±0.14 mm; P<0.001) compared with controls. Chronic obstructive pulmonary disease was associated with increased levels of each vascular biomarker independently of physiological confounders, smoking, and other cardiovascular risk factors. In this large case-controlled study, chronic obstructive pulmonary disease was associated with increased arterial stiffness, wave reflections, and subclinical atherosclerosis, independently of traditional cardiovascular risk factors. These findings suggest that the cardiovascular burden observed in this condition may be mediated through these mechanisms and supports the concept that chronic obstructive pulmonary disease is an independent risk factor for cardiovascular disease
Protocol and statistical analysis plan for the POOL study: establishing the safety of waterbirth for mothers and babies: a cohort study with nested qualitative component
The practicalities of adapting UK maternity clinical information systems for observational research: Experiences of the POOL study
Background
Using routinely collected clinical data for observational research is an increasingly important method for data collection, especially when rare outcomes are being explored. The POOL study was commissioned to evaluate the safety of waterbirth in the UK using routine maternity and neonatal clinical data. This paper describes the design, rationale, set-up and pilot for this data linkage study using bespoke methods.
Methods
Clinical maternity information systems hold many data items of value for research purposes, but often lack specific data items required for individual studies. This study used the novel method of amending an existing clinical maternity database for the purpose of collecting additional research data fields. In combination with the extraction of existing data fields, this maximised the potential use of existing routinely collected clinical data for research purposes, whilst reducing NHS staff data collection burden.
Wellbeing Software® provider of the Euroking® Maternity Information System, added new study specific data fields to their information system, extracted data from participating NHS sites and transferred data for matching with the National Neonatal Research Database to ascertain outcomes for babies admitted to neonatal units. Study set-up processes were put in place for all sites. The data extraction, linkage and cleaning processes were piloted with one pre-selected NHS site.
Results
Twenty-six NHS sites were set-up over 27 months (January 2019 - April 2021). Twenty-four thousand maternity records were extracted from the one NHS site, pertaining to the period January 2015 to March 2019. Data field completeness for maternal and neonatal primary outcomes were mostly acceptable. Neonatal identifiers flowed to the National Neonatal Research Database for successful matching and linkage between maternity and neonatal unit records.
Discussion
Piloting the data extraction and linkage highlighted the need for additional governance arrangements, training at NHS sites and new processes for the study team to ensure data quality and confidentiality are upheld during the study. Amending existing NHS electronic information systems and accessing clinical data at scale, is possible, but continues to be a time consuming and a technically challenging exercise
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