371 research outputs found

    A Monopole Near a Black Hole

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    We study an electric charge held at rest outside a magnetically charged black hole. We find that even if the electric charge is treated as a perturbation on a spherically symmetric magnetic Reissner-Nordstrom hole, the geometry at large distances is that of a magnetic Kerr-Newman black hole. When the charge approaches the horizon and crosses it, the exterior geometry becomes that of a Kerr-Newman hole with electric and magnetic charges and with total angular momentum given by the standard value for a charged monopole pair. Thus, in accordance with the "no-hair theorem", once the charge is captured by the black hole, the angular momentum associated with the charge monopole system, looses all traces of its exotic origin and it is perceived from the outside as common rotation. It is argued that a similar analysis performed on Taub-NUT space should give the same result, namely, if one holds an ordinary mass outside of the horizon of a Taub-NUT space with only magnetic mass, the system, as seen from large distances, is endowed with an angular momentum proportional to the product of the two kinds of masses. When the ordinary, electric, mass reaches the horizon, the exterior metric becomes that of a rotating Taub-NUT space.Comment: 8 pages. References adde

    Low Sensitivity of the Formol-Ethyl Acetate Sedimentation Concentration Technique in Low-Intensity Schistosoma japonicum Infections

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    Schistosoma japonicum is parasitic fluke (worm) found in China, Indonesia and the Philippines. A lot of effort has been put into combating the parasite, and the result has been a large drop in the number of infected people over the last decades. The average infected person also now has few worms, and hence excretes few eggs in stool. This has made it increasingly difficult to get a correct diagnosis by the diagnostic tests traditionally used. Tests based on detecting eggs in stool can be false-negative and tests detecting antibodies can be false-positive due to persisting antibodies or antibodies from other worm infections. Hence there is a need for new diagnostic strategies. Formol-ethyl acetate sedimentation concentration is a technique for detecting eggs in stool by microscopy, but has not to our knowledge been evaluated for S. japonicum. We compared the technique, using a single stool sample and a commercial preparation kit, with three tests traditionally used in the endemic countries (Kato-Katz thick smear, hatching test and indirect hemagglutination antibody detection). The sedimentation technique detected disappointing few positives and seems not to be an advantage in the diagnosis of low-intensity S. japonicum infection, compared to the traditionally used tests

    Individualised and complex experiences of integrative cancer support care: combining qualitative and quantitative data

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    Objectives: The widespread use of complementary therapies alongside biomedical treatment by people with cancer is not supported by evidence from clinical trials. We aimed to use combined qualitative and quantitative data to describe and measure individualised experiences and outcomes. Materials and methods In three integrative cancer support centres (two breast cancer only) in the UK, consecutive patients completed the individualised outcome questionnaire Measure Yourself Concerns and Wellbeing (MYCaW) before and after treatment. MYCaW collects quantitative data (seven-point scales) and written qualitative data and the qualitative data were analysed using published categories. Results: Seven hundred eighty-two participants, 92% female, mean age 51 years, nominated a wide range of concerns. Psychological and emotional concerns predominated. At follow-up, the mean change (improvement) in scores (n = 588) were: concern 1, 2.06 (95% CI 1.92–2.20); concern 2, 1.74 (95% CI 1.60–1.90); and well-being, 0.64 (95% CI 0.52–0.75). The most common responses to ‘what has been the most important aspect for you?’ were ‘receiving complementary therapies on an individual or group basis’ (26.2%); ‘support and understanding received from therapists’ (17.1%) and ‘time spent with other patients at the centres’ (16.1%). Positive (61.5%) and negative (38.5%) descriptions of ‘other things affecting your health’ correlated with larger and smaller improvement in concerns and well-being, respectively. Conclusions: In a multicentre evaluation, the MYCaW questionnaire provides rich data about patient experience, changes over time and perceptions of what was important to each individual with cancer within that experience. It is unlikely that meaningful evaluations of this complex intervention could be carried out by quantitative methods alone

    EMCCD calibration for astronomical imaging: Wide FastCam at the Telescopio Carlos Sánchez

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    The evident benefits of Electron Multiplying CCDs (EMCCDs) -speed, high sensitivity, low noise and their capability of detecting single photon events whilst maintaining high quantum efficiency- are bringing these kinds of detectors to many state-of-the-art astronomical instruments (Velasco et al. 2016; Oscoz et al. 2008). The EMCCDs are the perfect answer to the need for great sensitivity levels as they are not limited by the readout noise of the output amplifier, while conventional CCDs are, even when operated at high readout frame rates. Here we present a quantitative on-sky method to calibrate EMCCD detectors dedicated to astronomical imaging, developed during the commissioning process (Velasco et al. 2016) and first observations (Ricci et al. 2016, in prep.) with Wide FastCam (Marga et al. 2014) at Telescopio Carlos Sánchez (TCS) in the Observatorio del Teide

    Implementation of symptom protocols for nurses providing telephone-based cancer symptom management: a comparative case study

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    Background: The pan-Canadian Oncology Symptom Triage and Remote Support (COSTaRS) team developed 13 evidence-informed protocols for symptom management. Aim: To build an effective and sustainable approach for implementing the COSTaRS protocols for nurses providing telephone-based symptom support to cancer patients. Methods: A comparative case study was guided by the Knowledge to Action Framework. Three cases were created for three Canadian oncology programs that have nurses providing telephone support. Teams of researchers and knowledge users: (a) assessed barriers and facilitators influencing protocol use, (b) adapted protocols for local use, (c) intervened to address barriers, (d) monitored use, and (e) assessed barriers and facilitators influencing sustained use. Analysis was within and across cases. Results: At baseline, >85% nurses rated protocols positively but barriers were identified (64-80% needed training). Patients and families identified similar barriers and thought protocols would enhance consistency among nurses teaching self-management. Twenty-two COSTaRS workshops reached 85% to 97% of targeted nurses (N = 119). Nurses felt more confident with symptom management and using the COSTaRS protocols (p < .01). Protocol adaptations addressed barriers (e.g., health records approval, creating pocket versions, distributing with telephone messages). Chart audits revealed that protocols used were documented for 11% to 47% of patient calls. Sustained use requires organizational alignment and ongoing leadership support. Linking Evidence to Action: Protocol uptake was similar to trials that have evaluated tailored interventions to improve professional practice by overcoming identified barriers. Collaborating with knowledge users facilitated interpretation of findings, aided protocol adaptation, and supported implementation. Protocol implementation in nursing requires a tailored approach. A multifaceted intervention approach increased nurses' use of evidence-informed protocols during telephone calls with patients about symptoms. Training and other interventions improved nurses' confidence with using COSTaRS protocols and their uptake was evident in some documented telephone calls. Protocols could be adapted for use by patients and nurses globally.Dawn Stacey, Esther Green, Barbara Ballantyne, Joy Tarasuk, Myriam Skrutkowski, Meg Carley, Kim Chapman, Craig Kuziemsky, Erin Kolari, Brenda Sabo, Andréanne Saucier, Tara Shaw, Lucie Tardif, Tracy Truant, Greta G. Cummings, Doris Howel

    Shedding a new light on Huntington's disease: how blood can both propagate and ameliorate disease pathology

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    Huntington's disease (HD) is a monogenic neurodegenerative disorder resulting from a mutation in the huntingtin gene. This leads to the expression of the mutant huntingtin protein (mHTT) which provokes pathological changes in both the central nervous system (CNS) and periphery. Accumulating evidence suggests that mHTT can spread between cells of the CNS but here, we explored the possibility that mHTT could also propagate and cause pathology via the bloodstream. For this, we used a parabiosis approach to join the circulatory systems of wild-type (WT) and zQ175 mice. After surgery, we observed mHTT in the plasma and circulating blood cells of WT mice and post-mortem analyses revealed the presence of mHTT aggregates in several organs including the liver, kidney, muscle and brain. The presence of mHTT in the brain was accompanied by vascular abnormalities, such as a reduction of Collagen IV signal intensity and altered vessel diameter in the striatum, and changes in expression of Glutamic acid decarboxylase 65/67 (GAD65-67) in the cortex. Conversely, we measured reduced pathology in zQ175 mice by decreased mitochondrial impairments in peripheral organs, restored vessel diameter in the cortex and improved expression of Dopamine- and cAMP-regulated phosphoprotein 32 (DARPP32) in striatal neurons. Collectively, these results demonstrate that circulating mHTT can disseminate disease, but importantly, that healthy blood can dilute pathology. These findings have significant implications for the development of therapies in HD

    Conservation of Complex Nuclear Localization Signals Utilizing Classical and Non-Classical Nuclear Import Pathways in LANA Homologs of KSHV and RFHV

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    ORF73 latency-associated nuclear antigen (LANA) of the Kaposi's sarcoma-associated herpesvirus (KSHV) is targeted to the nucleus of infected cells where it binds to chromatin and mediates viral episome persistence, interacts with cellular proteins and plays a role in latency and tumorigenesis. A structurally related LANA homolog has been identified in the retroperitoneal fibromatosis herpesvirus (RFHV), the macaque homolog of KSHV. Here, we report the evolutionary and functional conservation of a novel bi-functional nuclear localization signal (NLS) in KSHV and RFHV LANA. N-terminal peptides from both proteins were fused to EGFP or double EGFP fusions to examine their ability to induce nuclear transport of a heterologous protein. In addition, GST-pull down experiments were used to analyze the ability of LANA peptides to interact with members of the karyopherin family of nuclear transport receptors. Our studies revealed that both LANA proteins contain an N-terminal arginine/glycine (RG)-rich domain spanning a conserved chromatin-binding motif, which binds directly to importin β1 in a RanGTP-sensitive manner and serves as an NLS in the importin β1-mediated non-classical nuclear import pathway. Embedded within this domain is a conserved lysine/arginine-(KR)-rich bipartite motif that binds directly to multiple members of the importin α family of nuclear import adaptors in a RanGTP-insensitive manner and serves as an NLS in the classical importin α/β-mediated nuclear import pathway. The positioning of a classical bipartite kr-NLS embedded within a non-classical rg-NLS is a unique arrangement in these viral proteins, whose nuclear localization is critical to their functionality and to the virus life cycle. The ability to interact with multiple import receptors provides alternate pathways for nuclear localization of LANA. Since different import receptors can import cargo to distinct subnuclear compartments, a multifunctional NLS may provide LANA with an increased ability to interact with different nuclear components in its multifunctional role to maintain viral latency
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