453 research outputs found

    A posterior epidural mass causing paraparesis in a 20-year-old healthy individual

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    We present a case of a posterior epidural abscess at the thoracic vertebral level causing paraparesia in a young, healthy individual with no otherwise predisposing factors, with normal laboratory findings, as diagnosed using fat-suppressed MR imaging. Spinal epidural abscess is a rare condition, encountered mostly in the midthoracic or lower lumbar vertebral levels of elderly patients, that has a high mortality and morbidity (18-31%) when diagnosis and treatment is delayed. It is rarely spontaneous and is usually accompanied by spinal osteomyelitis. Diagnosis is rather easy in cases of vertebral osteomyelitis or when classical clinical, laboratory and imaging findings are present. However, cases of spontaneous development, with no predisposing factors, and lack of abscess suggesting clinical and laboratory findings may be a diagnostic challenge. In such cases, other posterior epidural masses such as schwannoma, neurofibroma, meningioma and hematoma should be considered in the differential diagnosis. Both the clinician and the radiology physician should have a high suspicion of epidural abscesses, because their early diagnosis and treatment is important. In addition to routine MR images, fat-suppressed MR images prove helpful in the diagnosis of spontaneous epidural abscesses by showing the inflammatory changes in the paraspinal area

    Low-Energy Theorems from Holography

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    In the context of gauge/gravity duality, we verify two types of gauge theory low-energy theorems, the dilation Ward identities and the decoupling of heavy flavor. First, we provide an analytic proof of non-trivial dilation Ward identities for a theory holographically dual to a background with gluon condensate (the self-dual Liu--Tseytlin background). In this way an important class of low-energy theorems for correlators of different operators with the trace of the energy-momentum tensor is established, which so far has been studied in field theory only. Another low-energy relationship, the so-called decoupling theorem, is numerically shown to hold universally in three holographic models involving both the quark and the gluon condensate. We show this by comparing the ratio of the quark and gluon condensates in three different examples of gravity backgrounds with non-trivial dilaton flow. As a by-product of our study, we also obtain gauge field condensate contributions to meson transport coefficients.Comment: 32 pages, 4 figures, two references added, typos remove

    Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting

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    We present an analytical method to quantify clustering in super-resolution localization images of static surfaces in two dimensions. The method also describes how over-counting of labeled molecules contributes to apparent self-clustering and how the effective lateral resolution of an image can be determined. This treatment applies to clustering of proteins and lipids in membranes, where there is significant interest in using super-resolution localization techniques to probe membrane heterogeneity. When images are quantified using pair correlation functions, the magnitude of apparent clustering due to over-counting will vary inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. Over-counting does not yield apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (Fc{\epsilon}RI) on the plasma membranes of chemically fixed RBL-2H3 mast cells from images acquired using stochastic optical reconstruction microscopy (STORM) and scanning electron microscopy (SEM). We find that apparent clustering of labeled IgE bound to Fc{\epsilon}RI detected with both methods arises from over-counting of individual complexes. Thus our results indicate that these receptors are randomly distributed within the resolution and sensitivity limits of these experiments.Comment: 22 pages, 5 figure

    Lead and Cadmium Levels and Balance and Vestibular Dysfunction among Adult Participants in the National Health and Nutrition Examination Survey (NHANES) 1999–2004

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    Background: Few studies have been conducted to identify risk factors for balance and vestibular dysfunction in general populations, but previous studies have reported evidence of adverse effects of lead and cadmium on balance control in high-risk groups

    A Software Process Improvement Roadmap for IEC 62304: an Expert Review

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    Manufacturers of medical devices must comply with certain legislation and regulations before they can market their products in the European Union (EU). The EU has introduced this legislation and regulation to provide the frameworks by which manufacturers can produce safe and effective medical devices in a consistent manner. The EU has accomplished this by way of Medical Device Directives and harmonised standards. Manufactures, by demonstrating compliance with a harmonised standard, can be presumed to have complied with the essential requirements of the legislation. IEC 62304 Medical device software – Software lifecycle processes is a harmonised standard. However, the standard provides no clear directions for meeting the requirements of the standard. A Software Process Improvement (SPI) Roadmap for IEC 62304:2006 has been developed as a method for aiding medical device software development organizations in implementing the standard. The Roadmap is divided into two levels, the high level consists of the Activities and Tasks necessary for the im-plementation of the standard, while the low level contains the Design Patterns and How-to artefacts linked to the Tasks. This paper presents the findings from the expert review of the high level roadmap

    Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England

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    Purebred dog health is thought to be compromised by an increasing occurence of inherited diseases but inadequate prevalence data on common disorders have hampered efforts to prioritise health reforms. Analysis of primary veterinary practice clinical data has been proposed for reliable estimation of disorder prevalence in dogs. Electronic patient record (EPR) data were collected on 148,741 dogs attending 93 clinics across central and south-eastern England. Analysis in detail of a random sample of EPRs relating to 3,884 dogs from 89 clinics identified the most frequently recorded disorders as otitis externa (prevalence 10.2%, 95% CI: 9.1-11.3), periodontal disease (9.3%, 95% CI: 8.3-10.3) and anal sac impaction (7.1%, 95% CI: 6.1-8.1). Using syndromic classification, the most prevalent body location affected was the head-and-neck (32.8%, 95% CI: 30.7-34.9), the most prevalent organ system affected was the integument (36.3%, 95% CI: 33.9-38.6) and the most prevalent pathophysiologic process diagnosed was inflammation (32.1%, 95% CI: 29.8-34.3). Among the twenty most-frequently recorded disorders, purebred dogs had a significantly higher prevalence compared with crossbreds for three: otitis externa (P = 0.001), obesity (P = 0.006) and skin mass lesion (P = 0.033), and popular breeds differed significantly from each other in their prevalence for five: periodontal disease (P = 0.002), overgrown nails (P = 0.004), degenerative joint disease (P = 0.005), obesity (P = 0.001) and lipoma (P = 0.003). These results fill a crucial data gap in disorder prevalence information and assist with disorder prioritisation. The results suggest that, for maximal impact, breeding reforms should target commonly-diagnosed complex disorders that are amenable to genetic improvement and should place special focus on at-risk breeds. Future studies evaluating disorder severity and duration will augment the usefulness of the disorder prevalence information reported herein

    Efficacy of imidacloprid + moxidectin and selamectin topical solutions against the KS1 Ctenocephalides felis flea strain infesting cats

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    <p>Abstract</p> <p>Background</p> <p>Two studies were conducted to evaluate and compare the efficacy of imidacloprid + moxidectin and selamectin topical solutions against the KS1 flea strain infesting cats. In both studies the treatment groups were comprised of non-treated controls, 6% w/v selamectin (Revolution<sup>®</sup>; Pfizer Animal Health) topical solution and 10% w/v imidacloprid + 1% w/v moxidectin (Advantage <it>Multi</it><sup>® </sup>for Cats, Bayer Animal Health) topical solution. All cats were infested with 100 fleas on Days -2, 7, 14, 21, and 28. The difference in the studies was that in study #1 efficacy evaluations were conducted at 24 and 48 hours post-treatment or post-infestation, and in study #2 evaluations were conducted at 12 and 24 hours.</p> <p>Results</p> <p>In study #1 imidacloprid + moxidectin and the selamectin formulation provided 99.8% and 99.0% efficacy at 24 hours post-treatment. On day 28, the 24 hour efficacy of the selamectin formulation dropped to 87.1%, whereas the imidacloprid + moxidectin formulation provided 98.9% efficacy. At the 48 hour assessments following the 28 day infestations, efficacy of the imidacloprid + moxidectin and selamectin formulations was 96.8% and 98.3% respectively. In study # 2 the efficacy of the imidacloprid + moxidectin and selamectin formulations 12 hours after treatment was 100% and 69.4%, respectively. On day 28, efficacy of the imidacloprid + moxidectin and selamectin formulations 12 hours after infestation was 90.2% and 57.3%, respectively. In study #2 both formulations provided high levels of efficacy at the 24 hour post-infestation assessments, with selamectin and imidacloprid + moxidectin providing 95.3% and 97.5% efficacy, following infestations on day 28.</p> <p>Conclusions</p> <p>At the 24 and 48 hour residual efficacy assessments, the imidacloprid + moxidectin and selamectin formulations were similarly highly efficacious. However, the imidacloprid + moxidectin formulation provided a significantly higher rate of flea kill against the KS1 flea strain infesting cats at every 12 hour post-infestation residual efficacy assessment. Both formulations should provide excellent flea control for an entire month on cats.</p

    Hypoxia and oxidative stress in breast cancer: Oxidative stress: its effects on the growth, metastatic potential and response to therapy of breast cancer

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    Reactive oxygen species (ROS) damage DNA, but the role of ROS in breast carcinoma may not be limited to the mutagenic activity that drives carcinoma initiation and progression. Carcinoma cells in vitro and in vivo are frequently under persistent oxidative stress. In the present review, we outline potential causes of oxygen radical generation within carcinoma cells and explore the possible impact of oxidative stress on the clinical outcome of breast carcinoma

    A Measurement of Rb using a Double Tagging Method

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    The fraction of Z to bbbar events in hadronic Z decays has been measured by the OPAL experiment using the data collected at LEP between 1992 and 1995. The Z to bbbar decays were tagged using displaced secondary vertices, and high momentum electrons and muons. Systematic uncertainties were reduced by measuring the b-tagging efficiency using a double tagging technique. Efficiency correlations between opposite hemispheres of an event are small, and are well understood through comparisons between real and simulated data samples. A value of Rb = 0.2178 +- 0.0011 +- 0.0013 was obtained, where the first error is statistical and the second systematic. The uncertainty on Rc, the fraction of Z to ccbar events in hadronic Z decays, is not included in the errors. The dependence on Rc is Delta(Rb)/Rb = -0.056*Delta(Rc)/Rc where Delta(Rc) is the deviation of Rc from the value 0.172 predicted by the Standard Model. The result for Rb agrees with the value of 0.2155 +- 0.0003 predicted by the Standard Model.Comment: 42 pages, LaTeX, 14 eps figures included, submitted to European Physical Journal

    Measurement of the B+ and B-0 lifetimes and search for CP(T) violation using reconstructed secondary vertices

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    The lifetimes of the B+ and B-0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z(0) decays recorded at LEP. Z(0) --> b (b) over bar decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged data sample. The results aretau(B+) = 1.643 +/- 0.037 +/- 0.025 pstau(Bo) = 1.523 +/- 0.057 +/- 0.053 pstau(B+)/tau(Bo) = 1.079 +/- 0.064 +/- 0.041,where in each case the first error is statistical and the second systematic.A larger data sample of 3.1 million hadronic Z(o) decays has been used to search for CP and CPT violating effects by comparison of inclusive b and (b) over bar hadron decays, No evidence fur such effects is seen. The CP violation parameter Re(epsilon(B)) is measured to be Re(epsilon(B)) = 0.001 +/- 0.014 +/- 0.003and the fractional difference between b and (b) over bar hadron lifetimes is measured to(Delta tau/tau)(b) = tau(b hadron) - tau((b) over bar hadron)/tau(average) = -0.001 +/- 0.012 +/- 0.008
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