150 research outputs found

    Comparison of the Accuracy of X-ray, 2D-CT, 3D-CT, and Physical Modeling in Classification of Fractures about the Elbow Needing Operative Treatment

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    The goal of this study is to compare the accuracy of using X-ray, 2D-CT, 3D-CT, and physical modeling in classification of fractures about the elbow as a means of evaluating their relative utility in preoperative workup and treatment planning of fractures. Ten patients with fractures about the elbow that required operative fixation underwent preoperative X-ray, 2D-CT, 3D-CT, and physical modeling of their injury. Ten orthopaedic physicians classified each injury using each of those four modalities. The answers given by the 10 physicians were compared to an established correct classification for each case, and that data was used to compare the relative accuracy of each modality. The average accuracy for the given modalities was 62% for X-ray, 76% for 2D-CT, 80% for 3D-CT, and 88% for physical modeling. ANOVA analysis across all modalities revealed findings are statistically significant; however, when compared side by side, only moving from X-ray to 2D-CT yielded significant results. There was greater percentage correct classification achieved using the more advanced modalities, which therefore may theoretically result in more accurate preoperative planning. However, one must view this finding within the context and limits of this study, which is restricted by the relatively small sample size. Future study into methods of fracture characterization should be done to further evaluate findings such as these, with the goal of promoting better patient outcomes

    IKKα and IKKβ Each Function to Regulate NF-κB Activation in the TNF-Induced/Canonical Pathway

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    Activation of the transcription factor NF-kappaB by cytokines is rapid, mediated through the activation of the IKK complex with subsequent phosphorylation and degradation of the inhibitory IkappaB proteins. The IKK complex is comprised of two catalytic subunits, IKKalpha and IKKbeta, and a regulatory protein known as NEMO. Using cells from mice that are genetically deficient in IKKbeta or IKKalpha, or using a kinase inactive mutant of IKKbeta, it has been proposed that IKKbeta is critical for TNF-induced IkappaB phosphorylation/degradation through the canonical pathway while IKKalpha has been shown to be involved in the non-canonical pathway for NF-kappaB activation. These conclusions have led to a focus on development of IKKbeta inhibitors for potential use in inflammatory disorders and cancer.Analysis of NF-kappaB activation in response to TNF in MEFs reveals that IKKbeta is essential for efficient phosphorylation and subsequent degradation of IkappaB alpha, yet IKKalpha contributes to the NF-kappaB activation response in these cells as measured via DNA binding assays. In HeLa cells, both IKKalpha and IKKbeta contribute to IkappaB alpha phosphorylation and NF-kappaB activation. A kinase inactive mutant of IKKbeta, which has been used as evidence for the critical importance of IKKbeta in TNF-induced signaling, blocks activation of NF-kappaB induced by IKKalpha, even in cells that are deficient in IKKbeta.These results demonstrate the importance of IKKalpha in canonical NF-kappaB activation, downstream of cytokine treatment of cells. The experiments suggest that IKKalpha will be a therapeutic target in inflammatory disorders

    The Milky Way's dark matter halo appears to be lopsided

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    The atomic hydrogen gas (HI) disk in the outer region (beyond ~10 kpc from the centre) of Milky Way can provide valuable information about the structure of the dark matter halo. The recent 3-D thickness map of the outer HI disk from the all sky 21-cm line LAB survey, gives us a unique opportunity to investigate the structure of the dark matter halo of Milky Way in great detail. A striking feature of this new survey is the North-South asymmetry in the thickness map of the atomic hydrogen gas. Assuming vertical hydrostatic equilibrium under the total potential of the Galaxy, we derive the model thickness map of the HI gas. We show that simple axisymmetric halo models, such as softened isothermal halo (producing a flat rotation curve with V_c ~ 220 km/s) or any halo with density falling faster than the isothermal one, are not able to explain the observed radial variation of the gas thickness. We also show that such axisymmetric halos along with different HI velocity dispersion in the two halves, cannot explain the observed asymmetry in the thickness map. Amongst the non-axisymmetric models, it is shown that a purely lopsided (m=1, first harmonic) dark matter halo with reasonable HI velocity dispersion fails to explain the North-South asymmetry satisfactorily. However, we show that by superposing a second harmonic (m=2) out of phase onto a purely lopsided halo e.g. our best fit and more acceptable model A (with parameters \epsilon_{h}^{1}=0.2, \epsilon_{h}^{2}=0.18 and \sigma_{HI}=8.5 km/s) can provide an excellent fit to the observation and reproduce the North-South asymmetry naturally. The emerging picture of the asymmetric dark matter halo is supported by the \Lambda CDM halos formed in the cosmological N-body simulation.Comment: 37 pages, 8 figures, accepted for publication in Ap

    Optical Spectra of SNR Candidates in NGC 300

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    We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from optical spectra, we find that of 28 objects previously proposed as SNRs from optical observations, 22 meet this criterion with six showing [SII]/Ha of less than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated with the 28 previously proposed SNRs. Of these four, three (included in the 22 above) meet the criterion. In all, 22 of the 51 nebular objects meet the [SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc

    Behavioral/Systems/Cognitive Midbrain Dopamine Receptor Availability Is Inversely Associated with Novelty-Seeking Traits in Humans

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    Novelty-seeking personality traits are a major risk factor for the development of drug abuse and other unsafe behaviors. Rodent models of temperament indicate that high novelty responding is associated with decreased inhibitory autoreceptor control of midbrain dopamine neurons. It has been speculated that individual differences in dopamine functioning also underlie the personality trait of novelty seeking in humans. However, differences in the dopamine system of rodents and humans, as well as the methods for assessing novelty responding/seeking across species leave unclear to what extent the animal models inform our understanding of human personality. In the present study we examined the correlation between novelty-seeking traits in humans an
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