591 research outputs found
Using Borehole Electroseismic Measurements To Detect And Characterize Fractured (Permeable) Zones
We present a new type of field measurement capable of detecting and characterizing
fractured (permeable) zones intersecting a borehole. The method is based on measuring
electrical fields generated by a borehole Stoneley wave. In this paper, we describe
the measurement technique, present field data, and propose a theoretical model, which
correctly predicts amplitudes and phases of the electrical fields measured in the borehole experiment.
The theoretical model and the field data demonstrate that the measurements of the
Stoneley-wave-induced electrical fields can yield information about the interconnected
porosity, and possibly about the permeability of the formation around the borehole.
We derive an estimate of the interconnected porosity from the field data, and show that it correlates well with the density of fractures intersecting the borehole. Our results
suggest that the borehole electroseismic method can be developed into a logging or a
VSP tool, with possible applications in reservoir characterization.Massachusetts Institute of Technology. Borehole Acoustics and Logging Consortiu
1995 Data Acquisition Program At The Michigan Reservoir Delineation Research Facility
1995 was the most active year in recent history at the test site. Although the initial
year of 1983 saw more work, we were still basking in the glow of the modern "oil
boom"; the downsizing crash was ahead of us. In 1983, working around the clock, we
recorded 13 VSPs, a suite of logs, a reverse VSP, borehole gravity survey, and a 3-D
survey in two months of field time. In 1995, a single, four-man Conoco crew worked
ten to twelve hour days, for 70 days, and recorded a massive cross-well, orbital vibrator
data set-clearly a Herculean task. This paper outlines the pre-survey planning that took place in anticipation of that effort. In addition, we document the single well data
acquisition efforts of Conoco, Inc. and Lawrence .Berkeley Laboratory (LBL), and the
dipole logging work of Halliburton Energy Services. These data are in the handling
stages and processing has not yet begun
The Chagos Islands cases: the empire strikes back
Good governance requires the accommodation of multiple interests in the cause of decision making. However, undue regard for particular sectional interests can take their toll upon public faith in government administration. Historically, broad conceptions of the good of the commonwealth were employed to outweigh the interests of groups that resisted colonisation. In the decision making of the British Empire, the standard approach for justifying the marginalisation of the interests of colonised groups was that they were uncivilised and that particular hardships were the price to be paid for bringing to them the imperial dividend of industrial society. It is widely assumed that with the dismantling of the British Empire, such impulses and their accompanying jurisprudence became a thing of the past. Even as decolonisation proceeded apace after the Second World War, however, the United Kingdom maintained control of strategically important islands with a view towards sustaining its global role. In an infamous example from this twilight period of empire, in the 1960s imperial interests were used to justify the expulsion of the Chagos islanders from the British Indian Ocean Territory (BIOT). Into the twenty-first century, this forced elision of the UK’s interests with the imperial “common good” continues to take centre stage in courtroom battles over the islanders’ rights, being cited before domestic and international tribunals in order to maintain the Chagossians’ exclusion from their homeland. This article considers the new jurisprudence of imperialism which has emerged in a string of decisions which have continued to marginalise the Chagossians’ interests
Adult Rat Bones Maintain Distinct Regionalized Expression of Markers Associated with Their Development
The incidence of limb bone fracture and subsequent morbidity and mortality due to excessive bone loss is increasing in the progressively ageing populations of both men and women. In contrast to bone loss in the weight-bearing limb, bone mass in the protective skull vault is maintained. One explanation for this could be anatomically diverse bone matrix characteristics generated by heterogeneous osteoblast populations. We have tested the hypothesis that adult bones demonstrate site-specific characteristics, and report differences at the organ, cell and transcriptome levels. Limb bones contain greater amounts of polysulphated glycosaminoglycan stained with Alcian Blue and have significantly higher osteocyte densities than skull bone. Site-specific patterns persist in cultured adult bone-derived cells both phenotypically (proliferation rate, response to estrogen and cell volumes), and at the level of specific gene expression (collagen triple helix repeat containing 1, reelin and ras-like and estrogen-regulated growth inhibitor). Based on genome-wide mRNA expression and cluster analysis, we demonstrate that bones and cultured adult bone-derived cells segregate according to site of derivation. We also find the differential expression of genes associated with embryological development (Skull: Zic, Dlx, Irx, Twist1 and Cart1; Limb: Hox, Shox2, and Tbx genes) in both adult bones and isolated adult bone-derived cells. Together, these site-specific differences support the view that, analogous to different muscle types (cardiac, smooth and skeletal), skull and limb bones represent separate classes of bone. We assign these differences, not to mode of primary ossification, but to the embryological cell lineage; the basis and implications of this division are discussed
Kradljivci vremena u sestrinskoj praksi Time thieves in nursing practice
Svrha učinkovitosti upravljanja vremenom osigurava dostatni obim vremena za svrhe izvršavanja aktivnih radnih zadataka te za provođenje osobnih interesa i obveza. Upravljanje vremenom znači najučinkovitije korištenje vremena u svrhu provođenja aktivnih radnih zadataka. Danas postoje znanstveno verificirane metode koje poboljšavaju stupanj organizacije i učinkovitosti obaveznog radnog
vremena. Čimbenici koji se definiraju kao „kradljivci vremena“ neučinkovite su aktivnosti, neželjeni prekidi i događaji koji uzrokuju „krađu“ vremena. Opisujemo najučestalije kradljivce vremena koji su zabilježeni u sestrinskoj praksi na odjelima dviju klinika. Upotrebljen je upitnik „Samoprocjena - moji kradljivci
vremena“. U istraživanje su uključene 62 medicinske sestre. Anketu „Samoprocjena – moji kradljivci vremena“ ispunila su 62 ispitanika. Nema statistički značajne razlika u samoprocjeni postojanja kradljivaca vremena u odnosu na mjesto rada ispitanika, te na demografsko-sociološke čimbenike ispitanika
On the Relationship between the Uniqueness of the Moonshine Module and Monstrous Moonshine
We consider the relationship between the conjectured uniqueness of the
Moonshine Module, , and Monstrous Moonshine, the genus zero
property of the modular invariance group for each Monster group Thompson
series. We first discuss a family of possible meromorphic orbifold
constructions of based on automorphisms of the Leech
lattice compactified bosonic string. We reproduce the Thompson series for all
51 non-Fricke classes of the Monster group together with a new relationship
between the centralisers of these classes and 51 corresponding Conway group
centralisers (generalising a well-known relationship for 5 such classes).
Assuming that is unique, we then consider meromorphic
orbifoldings of and show that Monstrous Moonshine holds if
and only if the only meromorphic orbifoldings of give
itself or the Leech theory. This constraint on the
meromorphic orbifoldings of therefore relates Monstrous
Moonshine to the uniqueness of in a new way.Comment: 53 pages, PlainTex, DIAS-STP-93-0
Structural phase transition in two-dimensional tetramer-cuprate Na₅RbCu₄(AsO₄)₄Cl₂
Using Raman scattering and optical birefringence we have investigated a low-temperature phase transition
in single crystal of the two-dimensional Na₅RbCu₄(AsO₄)₄Cl₂. Phonon anomalies point to a first order
nature of the transition. The observed transition is most probably related to a order-disorder transition of the
Rb ion positions along the z axis within the ionic framework of mixed alkali metal chloride lattices
Expression of Regulatory Platelet MicroRNAs in Patients with Sickle Cell Disease
Background: Increased platelet activation in sickle cell disease (SCD) contributes to a state of hypercoagulability and confers a risk of thromboembolic complications. The role for post-transcriptional regulation of the platelet transcriptome by microRNAs (miRNAs) in SCD has not been previously explored. This is the first study to determine whether platelets from SCD exhibit an altered miRNA expression profile. Methods and Findings: We analyzed the expression of miRNAs isolated from platelets from a primary cohort (SCD = 19, controls = 10) and a validation cohort (SCD = 7, controls = 7) by hybridizing to the Agilent miRNA microarrays. A dramatic difference in miRNA expression profiles between patients and controls was noted in both cohorts separately. A total of 40 differentially expressed platelet miRNAs were identified as common in both cohorts (p-value 0.05, fold change>2) with 24 miRNAs downregulated. Interestingly, 14 of the 24 downregulated miRNAs were members of three families - miR-329, miR-376 and miR-154 - which localized to the epigenetically regulated, maternally imprinted chromosome 14q32 region. We validated the downregulated miRNAs, miR-376a and miR-409-3p, and an upregulated miR-1225-3p using qRT-PCR. Over-expression of the miR-1225-3p in the Meg01 cells was followed by mRNA expression profiling to identify mRNA targets. This resulted in significant transcriptional repression of 1605 transcripts. A combinatorial approach using Meg01 mRNA expression profiles following miR-1225-3p overexpression, a computational prediction analysis of miRNA target sequences and a previously published set of differentially expressed platelet transcripts from SCD patients, identified three novel platelet mRNA targets: PBXIP1, PLAGL2 and PHF20L1. Conclusions: We have identified significant differences in functionally active platelet miRNAs in patients with SCD as compared to controls. These data provide an important inventory of differentially expressed miRNAs in SCD patients and an experimental framework for future studies of miRNAs as regulators of biological pathways in platelets. © 2013 Jain et al
The Fecal Microbiome in Cats with Diarrhea
Recent studies have revealed that microbes play an important role in the pathogenesis of gastrointestinal (GI) diseases in various animal species, but only limited data is available about the microbiome in cats with GI disease. The aim of this study was to evaluate the fecal microbiome in cats with diarrhea. Fecal samples were obtained from healthy cats (n = 21) and cats with acute (n = 19) or chronic diarrhea (n = 29) and analyzed by sequencing of 16S rRNA genes, and PICRUSt was used to predict the functional gene content of the microbiome. Linear discriminant analysis (LDA) effect size (LEfSe) revealed significant differences in bacterial groups between healthy cats and cats with diarrhea. The order Burkholderiales, the families Enterobacteriaceae, and the genera Streptococcus and Collinsella were significantly increased in diarrheic cats. In contrast the order Campylobacterales, the family Bacteroidaceae, and the genera Megamonas, Helicobacter, and Roseburia were significantly increased in healthy cats. Phylum Bacteroidetes was significantly decreased in cats with chronic diarrhea (>21 days duration), while the class Erysipelotrichi and the genus Lactobacillus were significantly decreased in cats with acute diarrhea. The observed changes in bacterial groups were accompanied by significant differences in functional gene contents: metabolism of fatty acids, biosynthesis of glycosphingolipids, metabolism of biotin, metabolism of tryptophan, and ascorbate and aldarate metabolism, were all significantly (p<0.001) altered in cats with diarrhea. In conclusion, significant differences in the fecal microbiomes between healthy cats and cats with diarrhea were identified. This dysbiosis was accompanied by changes in bacterial functional gene categories. Future studies are warranted to evaluate if these microbial changes correlate with changes in fecal concentrations of microbial metabolites in cats with diarrhea for the identification of potential diagnostic or therapeutic targets.The open access fee for this work was funded through the Texas A&M University Open Access to Knowledge (OAK) Fund
- …