Search

We present a micromechanical characterization of shales from the Horn River Basin, NW Canada. The shales have contrasting mineralogy and microstructures and play different geomechanical roles in the field: the sample set covers an unconventional gas reservoir and the overburden unit that serves as the upper fracture barrier. Composition and texture were characterized using X‐ray diffraction, mercury injection porosimetry, and scanning electron microscopy (SEM). Grid nanoindentation testing was used to obtain the mechanical response of the dominant phases in the shale microstructure. Samples were indented parallel and perpendicular to the bedding plane to assess mechanical anisotropy. Chemical analysis of the grids with SEM‐EDS (energy dispersive X‐ray spectroscopy) was undertaken and the coupled chemo‐mechanical data was used in a statistical clustering procedure (Gaussian mixture model) to reveal the mechanical properties of each phase. The results show that the overburden consists of a soft clay matrix with highly anisotropic elastic stiffness, and stiffer but effectively isotropic inclusions of quartz and feldspar; the significant anisotropy of the overburden has been previously observed on a much larger scale using microseismic data. Creep displacement is concentrated in the clay matrix, which is the key phase for fracture barrier and seal applications. The reservoir units are harder and have more isotropic mechanical responses, primarily due to their lower clay content. Despite varied compositions and microstructures, the major phases of these shales (clay/organic matrix, quartz/feldspar, dolomite, and calcite) have unique mechanical signatures, which will aid identification in future micromechanical characterizations and facilitate their use in upscaling schemes. Plain Language Summary: The Horn River Basin is an area of northwest Canada where shale rocks have been used to produce gas. Reservoir shales are targeted for hydraulic fracturing while the overlying shale forms a barrier that stops fractures from propagating upwards. It is important for us to understand the different ways in which the reservoir and overburden shales respond to pressure changes due to fluid injection. This is because shales will be vital in many future subsurface technologies, for example, as top seals in geological CO2 storage. The mechanical response of shale is difficult to measure on core samples as they often break apart. Here, we used a technique called nanoindentation to measure the mechanical properties of the micron‐sized grains that form the shale. We conducted nanoindentation grids on both overburden and reservoir samples. We then carried out chemical analysis of the grids and used an automated clustering procedure to identify the mechanical properties of different minerals in each shale. We found that the overburden is dominated by a soft clay matrix that shows a tendency to creep over time, a process that would help close induced fractures. In contrast, the low‐clay reservoir shales were harder with much less creep. Key Points: The micromechanical properties of overburden and reservoir shales from the Horn River Basin are studied using grid nanoindentationThe overburden is dominated by a highly anisotropic clay matrix of low stiffness which shows large creep displacementReservoir shales have low clay content and are stiffer, more isotropic, and show much less creep than the overburden samples [ABSTRACT FROM AUTHOR]

Limited resources and access to healthcare in sub-Saharan Africa are associated with high rates of malnourished children, although many countries globally are demonstrating increasing childhood obesity. This study evaluated how well current age- or height-based formulae estimate the weight of children undergoing surgery in Zambia. All children under 14 years of age presenting for elective surgery at the University Teaching Hospital, Lusaka, had both height and weight measured. Their actual weight was compared against estimated weight from various formulae. The Broselow tape outperformed all the age-based formulae, demonstrating the lowest median percentage error of -5.8%, with 46.0% of estimates falling within 10% of the actual measured weight (p < 0.001). Of the 1111 children who were eligible for World Health Organization growth standard appraisal, 88 (8%) met the weight criteria for severe acute malnutrition. Our results are consistent with other studies in finding that the Broselow tape is the best estimator of weight in a lower middle-income country, followed by the original Advanced Paediatric Life Support formula if the Broselow tape is unavailable. [ABSTRACT FROM AUTHOR]

Significant differences in cytokine transcription were found between Oncorhynchus mykiss euthanized using the pharmacological agents MS-222 v. benzocaine and also when contrasting death induced by carbon dioxide asphyxiation v. physical methods (cervical dislocation). This study highlights the need to consider the potentially confounding effect of euthanization method on gene expression data. [ABSTRACT FROM AUTHOR]

The major histocompatibility complex (MHC) is central to maintaining the immunologic vigor of individuals and populations. Classical MHC class II genes were targeted for partial sequencing in sea otters ( Enhydra lutris) from populations in California, Washington, and Alaska. Sequences derived from sea otter peripheral blood leukocyte mRNAs were similar to those classified as DQA, DQB, DRA, and DRB in other species. Comparisons of the derived amino acid compositions supported the classification of these as functional molecules from at least one DQA, DQB, and DRA locus and at least two DRB loci. While limited in scope, phylogenetic analysis of the DRB peptide-binding region suggested the possible existence of distinct clades demarcated by geographic region. These preliminary findings support the need for additional MHC gene sequencing and expansion to a comprehensive study targeting additional otters. [ABSTRACT FROM AUTHOR]

Major histocompatibility complex (MHC) class II DRB genotypes were examined in two geographically isolated populations of California sea lions ( Zalophus californianus) (Gulf of California and California coastal Pacific Ocean). Genomic DNA from 227 California sea lions was examined using eight sequence-specific primer (SSP) pairs flanking the putative peptide-binding site. A total of 40 different Zaca-DRB genotype configurations were identified among the 227 individuals. Using SSP-PCR, significant differences were found between coastal California and Gulf of California Zalophus populations in numbers of DRB sequences per individual and configuration of sequences within individuals. Additionally, unique local patterns of MHC diversity were identified among the Midriff Island animals. These population differences are consistent with either ecologically distinct patterns of selection pressures and/or geographical isolation. The consequences of these partitioned MHC configurations at the population level are as yet unknown; however, the worldwide increase in emerging marine diseases lends urgency to their examination. [ABSTRACT FROM AUTHOR]

Community expectations and research demonstrate that consumers play an important role in shaping services for women with breast cancer. Consumer contribution has been mandated recently in Victoria, Australia, to ensure the inclusion of consumer involvement in the planning and decision-making processes within health organizations. As part of the redevelopment of breast services in Victoria, Southern Health has been funded to plan local improvements to care co-ordination for women diagnosed with breast cancer in the southern metropolitan area of Melbourne. The establishment of effective consumer participation in breast services is an integral aspect of this project and a range of initiatives has been undertaken to achieve meaningful consumer involvement including the appointment of a consumer advisor; appointment of staff with extensive knowledge in women's health and community development to the project; establishment of a consumer reference group; and plans made to improve the receptivity of health service systems to consumer input. A preliminary evaluation of this ongoing project has indicated that a productive role for consumers in service practice review and policy and planning activities has been established and some change and engagement of staff has occurred. There is still work to be done to promote the involvement of a wider range of health professionals and to increase the level of trust between consumers and staff. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to describe a practical method for the clutter-free, three-dimensional (3D) volume rendering of magnetic resonance angiographic (MRA) data. In MRA, clutter due to artifacts or nearby high-intensity structures prevents clear visualization of the vessel under investigation. We offer an alternative to the manual editing that is commonly used to remove clutter. The method is near automatic and requires the user to point at structures on a 3D maximum intensity projection (MIP) display. It utilizes recently developed fuzzy connected object delineation algorithms to extract the vessels of interest. Because the resulting definition is nonbinary, it can be displayed via MIP or more sophisticated volume-rendering techniques. The improved renditions are illustrated with several MRA studies. Implementation of the fuzzy connectedness method proved to be effective in removing the associated clutter in the images and, in some cases, dramatically improving visibility. Additionally, vessels could be extracted with a nominal number of points selected within the object by the user that retained most of the information present in the conventional MIP display. This could all be performed in a practical time frame: the first vessel delineation in 30 s, subsequent delineations in 2–10 s per view, all on a 100-MHz Pentium PC. Automatic delineation of vessels for 3D MRA visualization is feasible via fuzzy connectedness principles. The method retains the original intensity constitution, an advantage of the MIP method, and mostly eliminates the clutter commonly observed in MIP. Its speed and effectiveness make it feasible for routine clinical use.© 2000 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 62–70, 2000 [ABSTRACT FROM AUTHOR]

A consideration of the most common abbreviations in French leads to the study of linguistic phenomena related to the decomposition of French words into syllables and the accentuation of French words. [ABSTRACT FROM AUTHOR]

Fischer 344 rats (250--300 g) were exposed to the resulting aerosolsfrom the pyrolysis of Spectrex Fire Extinguishant (SFE) Formulation A, a pyrotechnically generated aerosol fire suppressant, at a loadingequivalent of 50 or 80 g m-3 air for 15 or 60 min. Exposures were conducted in a 700-l whole-body inhalation chamber under static conditions. The chamber atmosphere was analyzed for mass aerosol concentration and size distribution. Clinical observations were takenthroughout the exposure. Animals were euthanized at 1 h, 6 h, 24 h, 7 days or 14 days post-exposure and underwent histopathological examination, enzyme analyses and wet/dry lung weight determination. No deaths occurred during the study. Animals exhibited signs of dyspnea, coughing, lack of coordination and lethargy during each exposure. Thesesigns became more pronounced as the load and exposure length increased. No lesions were noted in the trachea, lung, heart or abdominal organs upon gross examination. A reversible pulmonary edema and olfactory necrosis were observed only in those animals exposed to an SFE loading equivalent to 80 g m- 3 for 60 min. Protein concentrations increased in the bronchoalveolar lavage but no changes in enzyme levels were observed. There was no significant difference between the control groups and the exposure groups for wet/dry lung weight determination. [ABSTRACT FROM AUTHOR]

In this report, we describe a case of periprocedural dislodgement of an Amplatzer Vascular Plug II device during percutaneous closure of severe paraprosthetic mitral regurgitation. The free plug in the left atrium was successfully retrieved percutaneously using a snare inserted through a sheath under live/real time three-dimensional transesophageal echocardiographic guidance. This proved crucial not only in guiding device deployment but also in detecting and helping management of complications., (© 2014, Wiley Periodicals, Inc.)

We evaluated the effects of minimally supervised, independent recreational activities on stereotypic vocal behavior in two chronic schizophrenic patients. In baseline sessions, subjects were observed during unstructured free time in the psychiatric ward. In treatment sessions, therapists presented preferred recreational materials (magazines, models, and art projects), verbally prompted on-task behavior every 20 min, and, in one condition, administered contingent tokens. Independent recreational activities reduced medium-rate self-talk in one subject and high-rate mumbling in a second subject by 60%-70%. Results were the same with or without contingent tokens. Apparent self-maintaining characteristics of these vocal responses are discussed.