The Role of Texture, Cracks, and Fractures in Highly Anisotropic Shales

Organic shales generally have low permeability unless fractures are present. However, how gas, oil, and water flows into these fractures remains enigmatic. The alignment of clay minerals and the alignment of fractures and cracks are effective means to produce seismic anisotropy. Thus, the detection and characterization of this anisotropy can be used to infer details about lithology, rock fabric, and fracture and crack properties within the subsurface. We present a study characterizing anisotropy using S wave splitting from microseismic sources in a highly anisotropic shale. We observe very strong anisotropy (up to 30%) with predominantly VTI (vertical transverse isotropy) symmetry, but with evidence of an HTI (horizontal transverse isotropy) overprint due to a NE striking vertical fracture set parallel to the maximum horizontal compressive stress. We observe clear evidence of a shear wave triplication due to anisotropy, which to our knowledge is one of only a very few observations of such triplications in field‐scale data. We use modal proportions of minerals derived from X‐ray fluorescence data combined with realistic textures to estimate the contribution of intrinsic anisotropy as well as possible contributions of horizontally aligned cracks. We find that aligned clays can explain much of the observed anisotropy and that any cracks contributing to the vertical transverse isotropy (VTI) must have a low ratio of normal to tangential compliance (ZN/ZT), typical of isolated cracks with low hydraulic connectivity. Subhorizontal cracks have also been observed in the reservoir, and we propose that their reactivation during hydraulic fracturing may be an important mechanism to facilitate gas flow

Refinement of the Child Amblyopia Treatment Questionnaire (CAT-QoL) using Rasch analysis

Aims or Purpose: The Child Amblyopia Treatment Questionnaire (CAT-QoL) was developed using a "bottom-up" methodological approach. Interviews with children with amblyopia identified items (questions) and response levels to be tested in a draft questionnaire consisting of 11 items (sad, feeling on face, hurt, doing schoolwork, cross, how other children treat you, doing things, worried, upset with family, playing with friends, happy). This study describes the refinement of the descriptive system for the CAT-QoL instrument using the application of Rasch analysis. METHODS: A multi-centre pilot study was conducted, and data collected from 342 participants. Participants were asked to self-complete the appropriate treatment version of the CAT-QoL questionnaire socio-demographic and clinical data were collected by the clinician using a standardised proforma. A "measure" of child's health was obtained from the parent by asking how they would rate their child's health over the previous week. Rasch analysis techniques were applied to refine the questionnaire. Rasch was used to examine response categories and collapse item response levels, identify poorly performing items, and explore local dependency of items. RESULTS: A total of 331 subjects were included in the study sample, however only 315 were accepted into the RUMM program as a number of subjects had missing questions responses on the CAT-QoL. RUMM also excluded a further 41 subjects as these demonstrated extreme responses. Disordered response categories were found for each item, requiring adjacent response levels to be combined. This was applied to all items, and the model fit was re-examined. Two items were found to have poor fit (cross and happy) and were removed from the measure and the model fit was re-examined. No statistically significant differential item functioning (DIF) was found for any item, using person factors of age, sex or general health. Two items showed some dependency (worried and upset with family), and the poorer fitting item was subsequently removed (upset with family). This resulted in a refined CAT-QoL instrument that consists of 8-items, each with three-level response scales. CONCLUSION: The refined CAT-QoL instrument includes the following items: sad, feeling on face, hurt, doing work at school, how other children treat you, doing things, worried and playing with friends. The CAT-QoL can be Rasch scored, with a range of 0-16 where a greater value indicates a worse quality of life (or greater impact of treatment on the individual). The CAT-QoL may be useful in determining how amblyopia treatment affects children, and offers an alternative to generic patient reported outcome measures

Prior event rate ratio adjustment produced estimates consistent with randomized trial: a diabetes case study

Objectives: Electronic health records (EHR) provide a valuable resource for assessing drug side-effects, but treatments are not randomly allocated in routine care creating the potential for bias. We conduct a case study using the Prior Event Rate Ratio (PERR) Pairwise method to reduce unmeasured confounding bias in side-effect estimates for two second-line therapies for type 2 diabetes, thiazolidinediones, and sulfonylureas. Study design and settings: Primary care data were extracted from the Clinical Practice Research Datalink (n = 41,871). We utilized outcomes from the period when patients took first-line metformin to adjust for unmeasured confounding. Estimates for known side-effects and a negative control outcome were compared with the A Diabetes Outcome Progression Trial (ADOPT) trial (n = 2,545). Results: When on metformin, patients later prescribed thiazolidinediones had greater risks of edema, HR 95% CI 1.38 (1.13, 1.68) and gastrointestinal side-effects (GI) 1.47 (1.28, 1.68), suggesting the presence of unmeasured confounding. Conventional Cox regression overestimated the risk of edema on thiazolidinediones and identified a false association with GI. The PERR Pairwise estimates were consistent with ADOPT: 1.43 (1.10, 1.83) vs. 1.39 (1.04, 1.86), respectively, for edema, and 0.91 (0.79, 1.05) vs. 0.94 (0.80, 1.10) for GI. Conclusion: The PERR Pairwise approach offers potential for enhancing postmarketing surveillance of side-effects from EHRs but requires careful consideration of assumptions.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.The MASTERMIND (MRC APBI Stratification and Extreme Response Mechanism IN Diabetes) consortium is funded by the U.K Medical Research Council funded study grant number MR/N00633X/1. The funder had no role in study design, data collection, data analysis, data interpretation, or writing of the report. IQVIA provided some funding for this project.published version, accepted version (12 month embargo), submitted versio

Shifting echo chambers in US climate policy networks

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data are available from the Climate Constituencies study at http://drfisher.umd.edu/CCP_REVISED.html.Although substantial attention has focused on efforts by the new Administration to block environmental policies, climate politics have been contentious in the US since well before the election of Donald Trump. In this paper, we extend previous work on empirical examinations of echo chambers in US climate politics using new data collected on the federal climate policy network in summer 2016. We test for the similarity and differences at two points in time in homophily and echo chambers using Exponential Random Graph Models (ERGM) to compare new findings from 2016 to previous work on data from 2010. We show that echo chambers continue to play a significant role in the network of information exchange among policy elites working on the issue of climate change. In contrast to previous findings where echo chambers centered on a binding international commitment to emission reductions, we find that the pre-existing echo chambers have almost completely disappeared and new structures have formed around one of the main components of the Obama Administration’s national climate policy: the Clean Power Plan. These results provide empirical evidence that science communication and policymaking at the elite level shift in relation to the policy instruments under consideration.MacArthur Foundatio

Preventive medication use among persons with limited life expectancy

Persons with limited life expectancy (LLE) – less than 1 year – are significant consumers of health care, are at increased risk of polypharmacy and adverse drug events, and have dynamic health statuses. Therefore, medication use among this population must be appropriate and regularly evaluated. The objective of this review is to assess the current state of knowledge and clinical practice presented in the literature regarding preventive medication use among persons with LLE. We searched Medline, Embase, and CINAHL using Medical Subject Headings. Broad searches were first conducted using the terms ‘terminal care or therapy’ or ‘advanced disease’ and ‘polypharmacy’ or ‘inappropriate medication’ or ‘preventive medicine’, followed by more specific searches using the terms ‘statins’ or ‘anti-hypertensives’ or ‘bisphosphonates’ or ‘laxatives’ and ‘terminal care’. Frameworks to assess appropriate versus inappropriate medications for persons with LLE, and the prevalence of potentially inappropriate medication use among this population, are presented. A considerable proportion of individuals with a known terminal condition continue to take chronic disease preventive medications until death despite questionable benefit. The addition of palliative preventive medications is advised. There is an indication that as death approaches the shift from a curative to palliative goal of care translates into a shift in medication use. This literature review is a first step towards improving medication use and decreasing polypharmacy in persons at the end of life. There is a need to develop consensus criteria to assess appropriate versus inappropriate medication use, specifically for individuals at the end of life

On the effect of metal loading on the reducibility and redox chemistry of ceria supported Pd catalysts

The effect of Pd loading on the redox characteristics of a ceria support was examined using in situ Pd K-edge XAS, Ce L3-edge XAS and in situ X-ray diffraction techniques. Analysis of the data obtained from these techniques indicates that the onset temperature for the partial reduction of Ce(IV) to Ce(III), by exposure to H2, varies inversely with the loading of Pd. Whilst the onset and completion temperatures of the reduction of Ce(IV) to Ce(III) are different, both samples yield the same maximal fraction of Ce(III) formation independent of Pd loading. Furthermore, the partial reduction of Ce is found to be concurrent with the reduction of PdO and demonstrated that the presence of metallic Pd is necessary for the reduction of the CeO2 support. Upon passivation by room temperature oxidation, a full oxidation of the reduced ceria support was observed. However, only a mild surface oxidation of Pd was identified. The mild passivation of the Pd is found to lead to a highly reactive sample upon a second reduction by H2. The onset of the reduction of Pd and Ce has been demonstrated to be independent of the Pd loading after a mild passivation with both samples exhibiting near room temperature reduction in the presence of H2

NAIL COSMETICS

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66131/1/j.1365-4362.1992.tb01368.x.pd

Toward High-Precision Measures of Large-Scale Structure

I review some results of estimation of the power spectrum of density fluctuations from galaxy redshift surveys and discuss advances that may be possible with the Sloan Digital Sky Survey. I then examine the realities of power spectrum estimation in the presence of Galactic extinction, photometric errors, galaxy evolution, clustering evolution, and uncertainty about the background cosmology.Comment: 24 pages, including 11 postscript figures. Uses crckapb.sty (included in submission). To appear in ``Ringberg Workshop on Large-Scale Structure,'' ed D. Hamilton (Kluwer, Amsterdam), p. 39