438 research outputs found

    Isotopic ratios of H, C, N, O, and S in comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy)

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    The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30m telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January - 3 February 2015. We detected 22 molecules and several isotopologues. The H216_2^{16}O and H218_2^{18}O production rates measured with Odin follow a periodic pattern with a period of 0.94 days and an amplitude of ~25%. The inferred isotope ratios in comet Lovejoy are 16^{16}O/18^{18}O = 499 ±\pm 24 and D/H = 1.4 ±\pm 0.4 ×104\times 10^{-4} in water, 32^{32}S/34^{34}S = 24.7 ±\pm 3.5 in CS, all compatible with terrestrial values. The ratio 12^{12}C/13^{13}C = 109 ±\pm 14 in HCN is marginally higher than terrestrial and 14^{14}N/15^{15}N = 145 ±\pm 12 in HCN is half the Earth ratio. Several upper limits for D/H or 12C/13C in other molecules are reported. From our observation of HDO in comet C/2014 Q2 (Lovejoy), we report the first D/H ratio in an Oort Cloud comet that is not larger than the terrestrial value. On the other hand, the observation of the same HDO line in the other Oort-cloud comet, C/2012 F6 (Lemmon), suggests a D/H value four times higher. Given the previous measurements of D/H in cometary water, this illustrates that a diversity in the D/H ratio and in the chemical composition, is present even within the same dynamical group of comets, suggesting that current dynamical groups contain comets formed at very different places or times in the early solar system.Comment: Accepted for publication in Astronomy and Astrophysic

    Observation of water vapor in the stratosphere of Jupiter with the Odin Space Telescope.

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    International audienceThe water vapor line at 557 GHz has been observed with the Odin space telescope with a high signal-to-noise ratio and a high spectral resolution on November 8, 2002. The analysis of this observation as well as a re-analysis of previously published observations obtained with the SubmillimeterWavelength Astronomy Satellite seem to favor a cometary origin (Shoemaker-Levy 9) for water in the stratosphere of Jupiter, in agreement with the ISO observation results. Our model predicts that the water line should become fainter and broader from 2007. The observation of such a temporal variablity would be contradictory with an IDP steady flux, thussupporting the SL9 source hypothesis

    A comprehensive assessment of environmental exposures among 1000 North American patients with primary sclerosing cholangitis, with and without inflammatory bowel disease

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    BACKGROUND: The relationships between primary sclerosing cholangitis (PSC) and the environment are largely unknown. AIM: To validate associations reported in previous studies and to identify novel environmental exposures among PSC patients. METHODS: We performed a multicenter, case-control analysis utilising self-administered questionnaires. Responses between cases (n = 1000) and controls (n = 663) were compared using multivariable logistic regression adjusted for age and gender. The model was further stratified based on inflammatory bowel disease (IBD) status (with IBD n = 741 without IBD n = 259). RESULTS: Smoking was associated with PSC only when IBD was present (OR, 0.5; 95% CI 0.4-0.7) but not among those PSC patients without IBD (OR, 0.9; 95% CI 0.7-1.2). Compared to controls, women with PSC (irrespective of the presence of IBD) were less likely to have received hormone replacement therapy (HRT; OR, 0.5; 95% CI 0.4-0.7) and were more likely to have recurrent urinary tract infections (OR, 1.6; 95% CI 1.2-2.3). PSC patients regardless of gender or IBD status were less likely to eat fish (OR, 0.4; 95% CI 0.3-0.6) and grilled/barbecued meat (OR, 0.8; 95% CI 0.7-0.9). In contrast, PSC patients with and without IBD were more likely to consume steak/burgers that were more well done (OR, 1.3; 95% CI 1.2-1.5). CONCLUSIONS: IBD (rather than PSC) is associated with smoking. Women with PSC are more likely to have recurrent urinary tract infections and less likely to receive HRT. Dietary intake and methods of food preparation differ in PSC patients when compared to controls

    Collective physician perspectives on non-oral medication approaches for the management of clinically relevant unresolved issues in Parkinson's disease: Consensus from an international survey and discussion program

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    Navigate PD was an educational program established to supplement existing guidelines and provide recommendations on the management of Parkinson's disease (PD) refractory to oral/transdermal therapies. It involved 103 experts from 13 countries overseen by an International Steering Committee (ISC) of 13 movement disorder specialists. The ISC identified 71 clinical questions important for device-aided management of PD. Fifty-six experts responded to a web-based survey, rating 15 questions as ‘critically important;’ these were refined to 10 questions by the ISC to be addressed through available evidence and expert opinion. Draft guidance was presented at international/national meetings and revised based on feedback. Key take-home points are: • Patients requiring levodopa >5 times daily who have severe, troublesome ‘off’ periods (>1–2 h/day) despite optimal oral/transdermal levodopa or non-levodopa-based therapies should be referred for specialist assessment even if disease duration is <4 years. • Cognitive decline related to non-motor fluctuations is an indication for device-aided therapies. If cognitive impairment is mild, use deep brain stimulation (DBS) with caution. For patients who have cognitive impairment or dementia, intrajejunal levodopa infusion is considered as both therapeutic and palliative in some countries. Falls are linked to cognitive decline and are likely to become more frequent with device-aided therapies. • Insufficient control of motor complications (or drug-resistant tremor in the case of DBS) are indications for device-aided therapies. Levodopa-carbidopa intestinal gel infusions or subcutaneous apomorphine pump may be considered for patients aged >70 years who have mild or moderate cognitive impairment, severe depression or other contraindications to DBS

    First comprehensive tool for screening pain in Parkinson's disease: the King's Parkinson's Disease Pain Questionnaire.

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    BACKGROUND AND PURPOSE: Pain is highly prevalent in Parkinson's disease (PD), impacting patients' ability, mood and quality of life. Detecting the presence of pain in its multiple modalities is necessary for adequate personalized management of PD. A 14-item, PD-specific, patient-based questionnaire (the King's Parkinson's Disease Pain Questionnaire, KPPQ) was designed corresponding to the rater-based KPP Scale (KPPS). The present multicentre study was aimed at testing the validity of this screening tool. METHODS: First, a comparison between the KPPQ scores of patients and matched controls was performed. Next, convergent validity, reproducibility (test-retest) and diagnostic performance of the questionnaire were analysed. RESULTS: Data from 300 patients and 150 controls are reported. PD patients declared significantly more pain symptoms than controls (3.96 ± 2.56 vs. 2.17 ± 1.39; P < 0.0001). The KPPQ convergent validity was high with KPPS total score (rS  = 0.80) but weak or moderate with other pain assessments. Test-retest reliability was satisfactory with kappa values ≥0.65 except for item 5, Dyskinetic pains (κ = 0.44), and the intraclass correlation coefficient (ICC) for the KPPQ total score was 0.98. After the scores of the KPPS were adapted for screening (0, no symptom; ≥1, symptom present), a good agreement was found between the KPPQ and the KPPS (ICC = 0.88). A strong correlation (rS  = 0.80) between the two instruments was found. The diagnostic parameters of the KPPQ were very satisfactory as a whole, with a global accuracy of 78.3%-98.3%. CONCLUSIONS: These results suggest that the KPPQ is a useful, reliable and valid screening instrument for pain in PD to advance patient-related outcomes

    A Consensus Set of Outcomes for Parkinson's Disease from the International Consortium for Health Outcomes Measurement

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    Background: Parkinson's disease (PD) is a progressive neurodegenerative condition that is expected to double in prevalence due to demographic shifts. Value-based healthcare is a proposed strategy to improve outcomes and decrease costs. To move towards an actual value-based health care system, condition-specific outcomes that are meaningful to patients are essential. Objective: Propose a global consensus standard set of outcome measures for PD. Methods: Established methods for outcome measure development were applied, as outlined and used previously by the International Consortium for Health Outcomes Measurement (ICHOM). An international group, representing both patients and experts from the fields of neurology, psychiatry, nursing, and existing outcome measurement efforts, was convened. The group participated in six teleconferences over a six-month period, reviewed existing data and practices, and ultimately proposed a standard set of measures by which patients should be tracked, and how often data should be collected. Results: The standard set applies to all cases of idiopathic PD, and includes assessments of motor and non-motor symptoms, ability to work, PD-related health status, and hospital admissions. Baseline demographic and clinical variables are included to enable case mix adjustment. Conclusions: The Standard Set is now ready for use and pilot testing in the clinical setting. Ultimately, we believe that using the set of outcomes proposed here will allow clinicians and scientists across the world to document, report, and compare PD-related outcomes in a standardized fashion. Such international benchmarks will improve our understanding of the disease course and allow for identification of 'best practices', ultimately leading to better informed treatment decisions.This project was funded by the International Consortium for Health Outcome Measurement.S

    Structured film-viewing preferences and practices : a quantitative analysis of hierarchies in screen and content selection amongst young people in Flanders

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    Aleit Veenstra, Philippe Meers and Daniel Biltereyst address a specific segment of a typical small-market audience—Flemish youth film viewers. Their study “Structured Film Viewing Preferences and Practices: A Quantitative Analysis of Hierarchies in Screen and Content Selection among Young People in Flanders” deals with one of the symptomatic problems of the era of convergent audiences, the multiplication of screens used for domestic consumption of audiovisual content. Building an intriguing empirical design, Veenstra and her colleagues aim to identify patterns of screen selection and their relation to the perceived value of Hollywood, European and domestic Flemish films. Their conclusion is that there are well-articulated hierarchies applied by the audience members in the selection of both film titles and reception screens and that, to put it simply, in the case of screens, size matters

    Digital health technology for non-motor symptoms in people with Parkinson's disease: Futile or future?

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    Item does not contain fulltextINTRODUCTION: There is an ongoing digital revolution in the field of Parkinson's disease (PD) for the objective measurement of motor aspects, to be used in clinical trials and possibly support therapeutic choices. The focus of remote technologies is now also slowly shifting towards the broad but more "hidden" spectrum of non-motor symptoms (NMS). METHODS: A narrative review of digital health technologies for measuring NMS in people with PD was conducted. These digital technologies were defined as assessment tools for NMS offered remotely in the form of a wearable, downloadable as a mobile app, or any other objective measurement of NMS in PD that did not require a hospital visit and could be performed remotely. Searches were performed using peer-reviewed literature indexed databases (MEDLINE, Embase, PsycINFO, Cochrane Database of Systematic Reviews, Cochrane CENTRAL Register of Controlled Trials), as well as Google and Google Scholar. RESULTS: Eighteen studies deploying digital health technology in PD were identified, for example for the measurement of sleep disorders, cognitive dysfunction and orthostatic hypotension. In addition, we describe promising developments in other conditions that could be translated for use in PD. CONCLUSION: Unlike motor symptoms, non-motor features of PD are difficult to measure directly using remote digital technologies. Nonetheless, it is currently possible to reliably measure several NMS and further digital technology developments are underway to offer further capture of often under-reported and under-recognised NMS

    Specific heat of classical disordered elastic systems

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    We study the thermodynamics of disordered elastic systems, applied to vortex lattices in the Bragg glass phase. Using the replica variational method we compute the specific heat of pinned vortons in the classical limit. We find that the contribution of disorder is positive, linear at low temperature, and exhibits a maximum. It is found to be important compared to other contributions, e.g. core electrons, mean field and non linear elasticity that we evaluate. The contribution of droplets is subdominant at weak disorder in d=3d=3.Comment: 4 pages, RevTe
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