2,047 research outputs found
Dispersion in bi-modal oil shales
1982 Spring.Includes bibliographic references (page 56).A series of leaching column experiments were conducted using 3 different grain sizes of spent oil shale from the Paraho retorting process. Electrical conductivity breakthrough data produced at 3 different seepage velocity rates were analyzed with the help of a least squares curve fitting computer model, CFITIM, developed by Van Genuchten (1981). Emphasis was placed on the identification of transport mechanisms which could explain the observed asymetry of the breakthrough curves. Comparison of the column breakthrough curves to a analytical dispersion model which took into account a micro pore diffusion transfer mechanism, produced poor correlation. When a linear sorption transfer mechanism was coupled with a micro pore diffusion transfer mechanism in the analytical model a much better match of the breakthrough data was obtained. The analytical model may prove useful in the development of a standard leaching column test procedure, however, it is suspected that the model parameters have little physical significance and therefore can only be used in fitting the breakthrough curves
Population Growth Characteristics of Incipient Colonies of the Eastern Subterranean Termite, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)
Growth of Reticulitermes flavipes (Kollar) incipient colonies during their first year was documented via a monthly destructive sampling census of 15 unique colonies, each headed by an inbred primary pair, for a total of 180 colonies. King and queen biomass greatly decreased during the first 2 months, coinciding with egg production and colony foundation, but their biomass remained relatively constant thereafter. Three cohorts of eggs were produced, with the greatest number of eggs (mean = 14.5) during the first month. Larvae were present at 1 month, and workers were first observed at 2 months. The survival rate of the initial brood was less than 100%, most likely due to cannibalism. A single soldier was first noted in some colonies at 6 months. Offspring biomass was equal to that of the reproductive pair at the 2-month census, double at 3 months, and quadruple at 11 months. One-year-old colonies ranged in size from 20 to 40 individuals, with an average of 28.9 individuals; total colony biomass was 39.8 mg. The growth rate of these R. flavipes colonies was much slower than was reported in other studies, but our observations are consistent with previous models and suggestions regarding colony growth
Institutional Changes to Support School Desegregation: Alternative Models Underlying Research and Implementation
Recent research studies and reports of current desegregation plans are examined against the background of two models of social systems: consensus and conflict. The article\u27s focus moves from the community to the school to the classroom to the individual
Inappropriate prescribing in the hospitalized elderly patient: Defining the problem, evaluation tools, and possible solutions
Potentially inappropriate medication (PIM) prescribing in older adults is quite prevalent and is associated with an increased risk for adverse drug events, morbidity, and utilization of health care resources. In the acute care setting, PIM prescribing can be even more problematic due to multiple physicians and specialists who may be prescribing for a single patient as well as difficulty with medication reconciliation at transitions and limitations imposed by hospital formularies. This article highlights critical issues surrounding PIM prescribing in the acute care setting such as risk factors, screening tools, and potential strategies to minimize this significant public health problem
Are different approaches to constructing initial data for binary black hole simulations of the same astrophysical situation equivalent?
Initial data for numerical evolutions of binary-black holes have been dominated by “conformally flat” (CF) data (i.e., initial data where the conformal background metric is chosen to be flat) because they are easy to construct. However, CF initial data cannot simulate nearly extremal spins, while more complicated “conformally curved” initial data (i.e., initial data in which the background metric is not explicitly chosen to be flat), such as initial data where the spatial metric is chosen to be proportional to a weighted superposition of two Kerr-Schild black holes can. Here we establish the consistency between the astrophysical results of these two initial data schemes for nonspinning binary systems. We evolve the inspiral, merger, and ringdown of two equal-mass, nonspinning black holes using superposed Kerr-Schild initial data and compare with an analogous simulation using CF initial data. We find that the resultant gravitational-waveform phases agree to within δϕ≲10^(-2) radians and the amplitudes agree to within δA/A≲5×10^(-3), which are within the numerical errors of the simulations. Furthermore, we find that the final mass and spin of the remnant black hole agree to one part in 10^5
miR-10a is aberrantly overexpressed in Nucleophosmin1 mutated acute myeloid leukaemia and its suppression induces cell death
<p>Abstract</p> <p>Background</p> <p>Acute myeloid leukaemia (AML) with nucleophosmin-1 (<it>NPM1</it>) mutation is a major subtype of AML. The <it>NPM1 </it>mutation induces a myeloproliferative disorder, but evidence indicates that other insults are necessary for the development of AML. We utilised microRNA microarrays and functional assays to determine if microRNA dysregulation could be involved in the pathogenesis of in <it>NPM1 </it>mutated (<it>NPM1<sup>mut</sup></it>)-AML.</p> <p>Results</p> <p>We used a stringent locked nucleic acid (LNA) based microRNA microarray platform to profile bone marrow samples of patients with normal karyotype AML. A panel of five microRNAs dichotomised AML patients according to their <it>NPM1 </it>mutational status. miR-10a, let-7b and let-7c were significantly over-expressed, while miR-130a and miR-335 were under-expressed in <it>NPM1<sup>mut</sup></it>-AML when compared to <it>NPM1<sup>wildtype</sup></it>-AML. Of these, miR-10a is the most differentially expressed in <it>NPM1<sup>mut</sup></it>-AML versus <it>NPM1<sup>wildtype</sup></it>-AML (> 10 fold higher as confirmed by qRT-PCR). To investigate the functions of miR-10a, the OCI-AML3 cell line was utilised, which is the only commercially available cell line bearing <it>NPM1<sup>mut</sup></it>. OCI-AML3 cells were firstly demonstrated to have a similarly high miR-10a expression to primary <it>NPM1<sup>mut</sup></it>-AML patient samples. Inhibition of miR-10a expression by miRCURY LNA Inhibitors (Exiqon) in these cells resulted in increased cell death as assessed by MTS, cell cycle and Annexin-V assays and reduced clonogenic capacity, indicative of an involvement in leukaemic cell survival. <it>In silico </it>filtering of bioinformatically predicted targets of miR-10a identified a number of potential mRNA targets with annotated functions in haematopoiesis, cell growth and apoptosis. Lucferase reporter assays confirmed a number of these putative tumorogenic genes that are miR-10a suppressible including <it>KLF4 </it>and <it>RB1CC1</it>. This provides a potential mechanism for the pathogenic role of miR-10a in <it>NPM1<sup>mut</sup></it>-AML.</p> <p>Conclusions</p> <p>This study provides, for the first time, <it>in vitro </it>evidence of a pro-survival role of miR-10a in <it>NPM1<sup>mut</sup></it>-AML, that it may contribute to the pathogenesis of <it>NPM1<sup>mut</sup></it>-AML and identifies putative tumorogenic targets.</p
Pre-melt-season sediment plume variability at Jokulsarlon, Iceland: a preliminary evaluation using in-situ spectroradiometry and satellite imagery
High-latitude atmospheric warming is impacting freshwater cycling, requiring techniques for monitoring the hydrology of sparsely-gauged regions. The submarine runoff of tidewater glaciers presents a particular challenge. We evaluate the utility of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery for monitoring turbid meltwater plume variability in the glacier lagoon Jökulsárlón, Iceland, for a short interval before the onset of the main melt season. Total Suspended Solids concentrations (TSS) of surface waters are related to remotely-sensed reflectance via empirical calibration between in-situ-sampled TSS and reflectance in a MODIS band 1-equivalent wavelength window. This study differs from previous ones in its application to an overturning tidewater glacier plume, rather than one derived from river runoff. The linear calibration improves on previous studies by facilitating a wider range of plume metrics than areal extent, notably pixel-by-pixel TSS values. Increasing values of minimum plume TSS over the study interval credibly represent rising overall turbidity in the lagoon as melting accumulates. Plume extent responds principally to consistently-strong offshore winds. Further work is required to determine the temporal persistence of the calibration, but remote plume observation holds promise for monitoring hydrological outputs from ungauged or ungaugeable systems
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