28 research outputs found
Creation and dynamics of two-dimensional skyrmions in antiferromagnetic spin-1 Bose-Einstein condensates
We numerically simulate the creation process of two-dimensional skyrmionic
excitations in antiferromagnetic spin-1 Bose--Einstein condensates by solving
the full three-dimensional dynamics of the system from the Gross--Pitaevskii
equation. Our simulations reproduce quantitatively the experimental results of
[Choi et al., Phys. Rev. Lett. 108, 035301 (2012)] without any fitting
parameters. Furthermore, we examine the stability of the skyrmion by computing
the temporal evolution of the condensate in a harmonic potential. The presence
of both the quadratic Zeeman effect and dissipation in the simulations is vital
for reproducing the experimentally observed decay time.Comment: 6 pages, 7 figure
Decay of an isolated monopole into a Dirac monopole configuration
We study numerically the detailed structure and decay dynamics of isolated
monopoles in conditions similar to those of their recent experimental
discovery. We find that the core of a monopole in the polar phase of a spin-1
Bose-Einstein condensate contains a small half-quantum vortex ring. Well after
the creation of the monopole, we observe a dynamical quantum phase transition
that destroys the polar phase. Strikingly, the resulting ferromagnetic order
parameter exhibits a Dirac monopole in its synthetic magnetic field.Comment: 6 pages, 5 figure
Ground-State Dirac Monopole
We show theoretically that a monopole defect, analogous to the Dirac magnetic
monopole, may exist as the ground state of a dilute spin-1 Bose-Einstein
condensate. The ground-state monopole is not attached to a single semi-infinite
Dirac string, but forms a point where the circulation of a single vortex line
is reversed. Furthermore, the three-dimensional dynamics of this monopole
defect are studied after the magnetic field pinning the monopole is removed and
the emergence of antimonopoles is observed. Our scheme is experimentally
realizable with the present-day state of the art
NEW LIGHT-WEIGHT STEREOSOPIC SPECTROMETRIC AIRBORNE IMAGING TECHNOLOGY FOR HIGH-RESOLUTION ENVIRONMENTAL REMOTE SENSING – CASE STUDIES IN WATER QUALITY MAPPING
A new Fabry-Perot interferometer (FPI) based light-weight spectrometric camera provides new possibilities for environmental
remote sensing applications. The sensor collects spectral data cubes with adjustable spectral properties in a rectangular image format,
and so stereoscopic data can be obtained by gathering images in block structures with overlapping images. The FPI camera thus
enables stereoscopic, spectrometric remote sensing applications with light-weight, low-cost airborne imaging systems. Our objective
is to investigate the processing and use of this new imaging technology in a water quality mapping. We carried out imaging
campaigns over a small lake in summer and autumn 2012 using a light-weight unmanned airborne vehicle (UAV) and a small
manned airborne vehicle (MAV). We present the preliminary results of these campaigns
2015/16 seasonal vaccine effectiveness against hospitalisation with influenza a(H1N1)pdm09 and B among elderly people in Europe: Results from the I-MOVE+ project
We conducted a multicentre test-negative caseâ\u80\u93control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged â\u89¥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases
Incidence rates of Guillain Barré (GBS), chronic fatigue/systemic exertion intolerance disease (CFS/SEID) and postural orthostatic tachycardia syndrome (POTS) prior to introduction of human papilloma virus (HPV) vaccination among adolescent girls in Finland, 2002â2012
Background: In Finland a vaccination programme against human papillomavirus (HPV) was introduced in November 2013 for girls aged 11â12 years with a catchup for girls 13â15 years. Allegations that HPV vaccine is causing Guillain Barré syndrome (GBS) and non-specific diagnostic entities, such as chronic fatigue syndrome/systemic exertion intolerance disease (CFS/SEID) and postural orthostatic tachycardia syndrome (POTS), continue to surface. We examined population register-based incidence rates of CFS/SEID, GBS and POTS to provide baseline data for future HPV vaccine safety evaluations. Methods: First diagnosis of CFS/SEID, GBS and POTS in girls aged 11â15 years were obtained from the National Hospital Discharge Register during 2002â2012. We considered the following ICD-10 codes: G93.3 for CFS; G61.0 for GBS and G90.9, G90.8, G93.3, I49.8 for POTS. We calculated incidence rates per 100,000 person-years with 95% confidence intervals (CI). Results: In total, 9 CFS/SEID, 19 GBS and 72 POTS cases were identified. The overall incidence rate was 0.53/100,000 (95% CI; 0.27â1.01) for CFS/SEID, 1.11 (95% CI; 0.71â1.74) for GBS and 4.21 (95%CI; 3.34â5.30) for POTS. Significant relative increase in annual incidence rate with a peak in 2012 was observed in CFS/SEID (33% (95% CI; 3.0â70.3: p=0.029) and POTS (16.5% (95% CI; 7.8â25.9: p<0.05), but not in GBS (5.4% (95% CI; â8.4â21.3: p=0.460). Conclusions: Our findings provide baseline estimates of CFS/SEID, GBS and POTS incidences in Finland. However, rates based on register data should be interpreted with caution, especially for non-specific diagnostic entities for which internationally and even nationally agreed criteria are still being discussed. To assess the associations with HPV vaccine, methods using register linkage for cohort and self-controlled case series should be explored in addition to factors contributing to patients seeking care, treating physicians setting the diagnoses, and their preference of using of codes for these clinical entities. Keywords: Papillomavirus vaccines, Vaccination adverse effects, Incidence rates, Guillain Barré syndrome, Chronic fatigue syndrome/Systemic exertion intolerance disease, Postural orthostatic tachycardia syndrome, Finlan