7,867 research outputs found
Vortex length, vortex energy and fractal dimension of superfluid turbulence at very low temperature
By assuming a self-similar structure for Kelvin waves along vortex loops with
successive smaller scale features, we model the fractal dimension of a
superfluid vortex tangle in the zero temperature limit. Our model assumes that
at each step the total energy of the vortices is conserved, but the total
length can change. We obtain a relation between the fractal dimension and the
exponent describing how the vortex energy per unit length changes with the
length scale. This relation does not depend on the specific model, and shows
that if smaller length scales make a decreasing relative contribution to the
energy per unit length of vortex lines, the fractal dimension will be higher
than unity. Finally, for the sake of more concrete illustration, we relate the
fractal dimension of the tangle to the scaling exponents of amplitude and
wavelength of a cascade of Kelvin waves.Comment: 12 pages, 1 figur
Turbulent superfluid profiles in a counterflow channel
We have developed a two-dimensional model of quantised vortices in helium II
moving under the influence of applied normal fluid and superfluid in a
counterflow channel. We predict superfluid and vortex-line density profiles
which could be experimentally tested using recently developed visualization
techniques.Comment: 3 double figures, 9 page
MicroRNA-30d and -483-3p for bi-ventricular remodelling and miR-126-3p for pulmonary hypertension in advanced heart failure
Aims: MicroRNAs play a role in pathogenic mechanisms leading to heart failure. We measured a panel of 754 miRNAs in the myocardial tissue and in the serum of patients with heart failure with reduced ejection fraction due to dilatative idiopathic cardiomyopathy (DCM, N = 10) or ischaemic cardiomyopathy (N = 3), referred to left ventricular assist device implant. We aim to identify circulating miRNAs with high tissue co-expression, significantly associated to echocardiographic and haemodynamic measures. Methods and results: We have measured a panel of 754 miRNAs in the myocardial tissue [left ventricular (LV) apex] and in the serum obtained at the same time in a well selected study population of end-stage heart failure with reduced ejection fraction due to either DCM or ischaemic cardiomyopathy, referred to continuous flow left ventricular assist device implant. We observed moderate agreement for miR-30d, miR-126-3p, and miR-483-3p. MiR-30d was correlated to LV systolic as well as diastolic volumes (r = 0.78, P = 0.001 and r = 0.80, P = 0.005, respectively), while miR-126-3p was associated to mPAP and PCWP (r = −0.79, P = 0.007 and r = −0.80, P = 0.005, respectively). Finally, serum miR-483-3p had an association with right ventricular end diastolic diameter (r = −0.73, P = 0.02) and central venous pressure (CVP) (r − 0.68 p 0.03). Conclusions: In patients with DCM, few miRNAs are co-expressed in serum and tissue: They are related to LV remodelling (miR-30d), post-capillary pulmonary artery pressure (miR-126-3p), and right ventricular remodelling/filling pressures (miR-483-3p). Further studies are needed to confirm their role in diagnosis, prognosis or as therapeutic targets in heart failure with reduced ejection fraction
Safety and Dose-Response of Vidofludimus Calcium in Relapsing Multiple Sclerosis: Extended Results of a Placebo-Controlled Phase 2 Trial
BACKGROUND AND OBJECTIVES: Vidofludimus calcium suppressed MRI disease activity compared with placebo in patients with relapsing-remitting multiple sclerosis (RRMS) in the first cohort of the phase 2 EMPhASIS study. Because 30 mg and 45 mg showed comparable activity on multiple end points, the study enrolled an additional low-dose cohort to further investigate a dose-response relationship. METHODS: In a randomized, placebo-controlled, phase 2 trial, patients with RRMS, aged 18-55 years, and with ≥2 relapses in the last 2 years or ≥1 relapse in the last year, and ≥1 gadolinium-enhancing brain lesion in the last 6 months. Patients were randomly assigned (1:1:1) vidofludimus calcium (30 or 45 mg) or placebo in cohort 1 and vidofludimus calcium (10 mg) or placebo (4:1) in cohort 2 for 24 weeks. The primary end point was the cumulative number of combined unique active (CUA) lesions at week 24. Secondary end points were clinical outcomes and safety. RESULTS: Across cohorts 1 and 2, 268 patients were randomized to placebo (n = 81), 10 mg (n = 47) vidofludimus calcium, 30 mg (n = 71) vidofludimus calcium, or 45 mg (n = 69) vidofludimus calcium. The mean cumulative CUA lesions over 24 weeks was 5.8 (95% CI 4.1-8.2) for placebo, 5.9 (95% CI 3.9-9.0) for 10 mg treatment group, 1.4 (95% CI 0.9-2.1) for 30 mg treatment group, and 1.7 (95% CI 1.1-2.5) for 45 mg treatment group. Serum neurofilament light chain decreased in a dose-dependent manner. The number of patients with confirmed disability worsening after 24 weeks was 3 (3.7%) patients receiving placebo and 3 (1.6%) patients receiving any dose of vidofludimus calcium. Treatment-emergent adverse events occurred in 35 (43%) placebo patients compared with 11 (23%) and 71 (37%) patients in the 10 mg or any dose of vidofludimus calcium groups, respectively. The incidence of liver enzyme elevations and infections were similar between placebo and any dose of vidofludimus calcium. No new safety signals were observed. DISCUSSION: Compared with placebo, vidofludimus calcium suppressed the development of new brain lesions with daily doses of 30 mg and 45 mg, but not 10 mg, establishing the lowest efficacious dose is 30 mg. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that among adults with active RRMS and ≥1 Gd+ brain lesion in the past 6 months, the cumulative number of active lesions decreased with vidofludimus calcium. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov (NCT03846219) and EudraCT (2018-001896-19)
Healthcare providers' views on the acceptability of financial incentives for breastfeeding:a qualitative study
BACKGROUND: Despite a gradual increase in breastfeeding rates, overall in the UK there are wide variations, with a trend towards breastfeeding rates at 6–8 weeks remaining below 40% in less affluent areas. While financial incentives have been used with varying success to encourage positive health related behaviour change, there is little research on their use in encouraging breastfeeding. In this paper, we report on healthcare providers’ views around whether using financial incentives in areas with low breastfeeding rates would be acceptable in principle. This research was part of a larger project looking at the development and feasibility testing of a financial incentive scheme for breastfeeding in preparation for a cluster randomised controlled trial. METHODS: Fifty–three healthcare providers were interviewed about their views on financial incentives for breastfeeding. Participants were purposively sampled to include a wide range of experience and roles associated with supporting mothers with infant feeding. Semi-structured individual and group interviews were conducted. Data were analysed thematically drawing on the principles of Framework Analysis. RESULTS: The key theme emerging from healthcare providers’ views on the acceptability of financial incentives for breastfeeding was their possible impact on ‘facilitating or impeding relationships’. Within this theme several additional aspects were discussed: the mother’s relationship with her healthcare provider and services, with her baby and her family, and with the wider community. In addition, a key priority for healthcare providers was that an incentive scheme should not impact negatively on their professional integrity and responsibility towards women. CONCLUSION: Healthcare providers believe that financial incentives could have both positive and negative impacts on a mother’s relationship with her family, baby and healthcare provider. When designing a financial incentive scheme we must take care to minimise the potential negative impacts that have been highlighted, while at the same time recognising the potential positive impacts for women in areas where breastfeeding rates are low
Search for Branons at LEP
We search, in the context of extra-dimension scenarios, for the possible
existence of brane fluctuations, called branons. Events with a single photon or
a single Z-boson and missing energy and momentum collected with the L3 detector
in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are
analysed. No excess over the Standard Model expectations is found and a lower
limit at 95% confidence level of 103 GeV is derived for the mass of branons,
for a scenario with small brane tensions. Alternatively, under the assumption
of a light branon, brane tensions below 180 GeV are excluded
Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP
Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are
used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~
events. Spin correlations are favoured by data, and found to agree with the
Standard Model predictions. In addition, correlations between the W-boson decay
planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events.
Decay-plane correlations, consistent with zero and with the Standard Model
predictions, are measured
Measurement of Exclusive rho^0 rho^0 Production in Two-Photon Collisions at High Q^2 at LEP
Exclusive rho rho production in two-photon collisions involving a single
highly virtual photon is studied with data collected at LEP at centre-of-mass
energies 89GeV < \sqrt{s} < 209GeV with a total integrated luminosity of
854.7pb^-1 The cross section of the process gamma gamma^* -> rho rho is
determined as a function of the photon virtuality, Q^2 and the two-photon
centre-of-mass energy, Wgg, in the kinematic region: 1.2GeV^2 < Q^2 < 30GeV^2
and 1.1GeV < Wgg < 3GeV
Formation of the in Two-Photon Collisions at LEP
The two-photon width of the meson has been
measured with the L3 detector at LEP. The is studied in the decay
modes , KK, KK,
KK, , , and
using an integrated luminosity of 140 pb at GeV and
of 52 pb at GeV. The result is
(BR) keV. The dependence of the cross section is studied for
GeV. It is found to be better described by a Vector Meson
Dominance model form factor with a J-pole than with a -pole. In addition,
a signal of events is observed at the mass. Upper limits
for the two-photon widths of the , , and are also
given
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