693 research outputs found

    Omega time transmissions and receiving requirements

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    A short history is given of the development of dual VLF time transmission techniques. The theory of time recovery from the relative phase of the dual frequency transmission is presented. The transmission and receiving requirements for cycle identification and cycle ambiguity resolution are described. Finally, an experiment to test the capability of time transmission of the OMEGA system is propose

    You Can Simplify Oat-Legume-Grass Seeding

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    An oat-legume-grass mixture can be seeded successfully in one trip over the field with a single-hopper machine. Seed separation isn\u27t a problem, and you can achieve uniform seed distribution and a satisfactory planting depth

    Minimally invasive atrioventricular valve surgery – current status and future perspectives

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    We are currently witnessing rapid evolution in minimally invasive and catheter-based atrioventricular valve interventions as acceptable alternatives to classic sternotomy access (CSA). Collectively, minimally invasive atrioventricular valve surgery (MIAS) is associated with significant learning curves and its routine application is met with varying degrees of enthusiasm in view of strict quality control, clinical governance and outcome reporting. Whether the reported potential benefits and comparable efficacy across a range of long-term outcome measures reported by experienced MIAS centres can be translated into general international surgical practice, are not well defined. This paper describes the historic evolution of MIAS, the contemporary clinical outcomes of MIAS compared with CSA, and the application of MIAS in “real-life” general practice

    Engaged in Research/Achieving Balance: A Case Example of Teaching Research to Masters of Social Work Students

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    This article considers the use of participatory action research and Photovoice as a tool for engaging graduate level social work students in research education. Photovoice is an investigative tool that assists people in critically reflecting on the everyday social and political realities of their lives, enriching their understanding of their communities and the issues pertinent to them, while at the same time, giving them a voice from which to educate others on these issues. In the context of a group assignment, 26 social work students, enrolled in an introductory graduate research course, were asked to reflect upon the question, “What does balance look like for you in the MSW program?” Thirty-two photographs with captions were submitted and analyzed by class members for relevant themes. Balance was described as existing along a continuum from balanced to unbalanced and was comprised of four major themes: connection, nurturance, keeping perspective, and disengagement. Although this teaching strategy was not formally assessed, preliminary impressions are that students benefited from participating in the Photovoice activity

    Defining behavioral and molecular differences between summer and migratory monarch butterflies

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    BACKGROUND: In the fall, Eastern North American monarch butterflies (Danaus plexippus) undergo a magnificent long-range migration. In contrast to spring and summer butterflies, fall migrants are juvenile hormone deficient, which leads to reproductive arrest and increased longevity. Migrants also use a time-compensated sun compass to help them navigate in the south/southwesterly direction en route for Mexico. Central issues in this area are defining the relationship between juvenile hormone status and oriented flight, critical features that differentiate summer monarchs from fall migrants, and identifying molecular correlates of behavioral state. RESULTS: Here we show that increasing juvenile hormone activity to induce summer-like reproductive development in fall migrants does not alter directional flight behavior or its time-compensated orientation, as monitored in a flight simulator. Reproductive summer butterflies, in contrast, uniformly fail to exhibit directional, oriented flight. To define molecular correlates of behavioral state, we used microarray analysis of 9417 unique cDNA sequences. Gene expression profiles reveal a suite of 40 genes whose differential expression in brain correlates with oriented flight behavior in individual migrants, independent of juvenile hormone activity, thereby molecularly separating fall migrants from summer butterflies. Intriguing genes that are differentially regulated include the clock gene vrille and the locomotion-relevant tyramine beta hydroxylase gene. In addition, several differentially regulated genes (37.5% of total) are not annotated. We also identified 23 juvenile hormone-dependent genes in brain, which separate reproductive from non-reproductive monarchs; genes involved in longevity, fatty acid metabolism, and innate immunity are upregulated in non-reproductive (juvenile-hormone deficient) migrants. CONCLUSION: The results link key behavioral traits with gene expression profiles in brain that differentiate migratory from summer butterflies and thus show that seasonal changes in genomic function help define the migratory state

    Uniqueness of Bessel models: the archimedean case

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    In the archimedean case, we prove uniqueness of Bessel models for general linear groups, unitary groups and orthogonal groups.Comment: 22 page

    High resolution CT diagnosis of isolated fracture of the malleus handle.

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    We report a case of a 48-year-old woman with a sudden-onset unexplained conductive unilateral hearing loss. There was no improvement after a trial with systemic corticosteroids. On otomicroscopy, the right tympanic membrane showed an abnormal outline of the malleus handle. Pneumatic otoscopy revealed excessive movement of the umbo compared with the lateral process. Audiometric testing showed a conductive hearing loss in the right ear, with an average pure-tone audiometry of air conduction of 40 dB and a maximum air-bone gap of 45 dB at 500 Hz. Tuning fork tests confirmed conductive hearing loss. Tympanometry showed increased compliance in the right ear and an absent ipsilateral stapedial reflex in response to a broad-band stimulus. High resolution computed tomography (CT) imaging of the temporal bone was performed by a high-definition CT system (Discovery CT750 HD®, GE, Hounslow, England). MIP (Maximum Intensity Projection) coronal ultrafine (around 0.1 mm) reconstructions of the malleus revealed a small non-displaced isolated fracture of the malleus handle (Fig. A and B). On the left there was a continuous appearence of the middle ear ossicles. During surgery, the isolated fracture of the right malleus handle was visualised and an ossiculoplasty was performed using a hydroxylapatite bone cement (OtoMimix®, Biomet, Jacksonville, Florida) (Fig. C). Postoperatively, average pure-tone audiometry of air condition improved to 30 dB, and maximum air-bone gap improved to 35 dB at 500 Hz

    Calpain cleavage and subcellular characterisation of the ferlin family.

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    The ferlins are a family of C2-domain containing proteins. C2 domains regulate vesicle fusion in synaptotagmins, and animal models of ferlin deficiency display pathologies related to Ca2+-dependent vesicle fusion. Dysferlin mutations cause limb-girdle muscular dystrophy due to defective membrane repair. Our group has previously shown that Ca2+-dependent proteases, calpains, cleave dysferlin following membrane injury, releasing mini-dysferlinC72, that we hypothesise mediates membrane repair. Otoferlin mutations cause non-syndromic deafness, while no pathology causing mutations have been identified in other ferlins. My project establishes that dysferlin and myoferlin, type-I ferlins, are present at the plasma membrane and endo-lysosomal pathway while otoferlin and Fer1L6, type-II ferlins, are present at the plasma membrane and recycling trans-Golgi compartments. I also show that dysferlin is cleaved to mini-dysferlinC72 following injury in all cell types by the ubiquitous calpains-1 and -2 in the alternatively spliced exon 40a, indicating dysferlin cleavage is a fundamental response to membrane injury. Exon 40a-containing dysferlin recruits to sites of membrane injury in myotubes, indicating mini-dysferlinC72 may function directly at sites of injury. Finally, I have shown that calpains also cleave otoferlin and myoferlin. Cleavage of other ferlins indicates ferlin cleavage is an evolutionarily conserved event, predating the split between type-I and type-II ferlins

    Denominators of Eisenstein cohomology classes for GL_2 over imaginary quadratic fields

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    We study the arithmetic of Eisenstein cohomology classes (in the sense of G. Harder) for symmetric spaces associated to GL_2 over imaginary quadratic fields. We prove in many cases a lower bound on their denominator in terms of a special L-value of a Hecke character providing evidence for a conjecture of Harder that the denominator is given by this L-value. We also prove under some additional assumptions that the restriction of the classes to the boundary of the Borel-Serre compactification of the spaces is integral. Such classes are interesting for their use in congruences with cuspidal classes to prove connections between the special L-value and the size of the Selmer group of the Hecke character.Comment: 37 pages; strengthened integrality result (Proposition 16), corrected statement of Theorem 3, and revised introductio
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