Climate and climate change in the sub-Antarctic

Meteorologically, the sub-Antarctic is sparsely represented in the climate literature. Drawing on a variety of sources that are either directly or indirectly linked to the sub-Antarctic, an overview of the climate of the sub-Antarctic is presented, In doing so, we note that, for the most part, the sub-Antarctic climate is more or less fixed to mean monthly air temperatures between -5C and +15C. Brief discussion explores the roles of teleconnections that appear to affect the sub-Antarctic climate, focusing on the Southern Hemisphere Annular Mode (SAM). We report on meteorological evidence of climate change that has occurred in the recent history of the sub-Antarctic and note that rainfall dimate-change signals from Marion and Macquarie islands are consistent with trends associated with the SAM index. We report that modelling suggests that the climate of the sub-Antarctic will continue to change through the twenty-first century in line with twentieth-century trends. The need for more research into the climate of the sub-Antarctic, underpinned by a robust databank of quality controlled sub-Antarctic meteorological data, is noted

Comment on "New Experimental Limit for the Electric Dipole Moment of the Neutron"

A new limit for the neutron electric dipole moment has been recently reported. This new limit is obtained by combining the result from a previous experiment with the result from a more recent experiment that has much worse statistical accuracy. We show that the old result has a systematic error possibly four times greater than the new limit, and under the circumstances, averaging of the old and new results is statistically invalid. The conclusion is that it would be more appropriate to quote two independent but mutually supportive limits as obtained from each experiment separately.Comment: 7 pages, 2 figure

Age-dependent association of white matter abnormality with cognition after TIA or minor stroke

ObjectiveTo investigate if the association between MRI-detectable white matter hyperintensity (WMH) and cognitive status reported in previous studies persists at older ages (>80 years), when some white matter abnormality is almost universally reported in clinical practice.MethodsConsecutive eligible patients from a population-based cohort of all TIA/nondisabling stroke (Oxford Vascular Study) underwent multimodal MRI, including fluid-Attenuated inversion recovery and diffusion-weighted imaging, allowing automated measurement of WMH volume, mean diffusivity (MD), and fractional anisotropy (FA) in normal-Appearing white matter using FSL tools. These measures were related to cognitive status (Montreal Cognitive Assessment) at age 6480 vs >80 years.ResultsOf 566 patients (mean [range] age 66.7 [20-102] years), 107 were aged >80 years. WMH volumes and MD/FA were strongly associated with cognitive status in patients aged 6480 years (all p < 0.001 for WMH, MD, and FA) but not in patients aged >80 years (not significant for WMH, MD, and FA), with age interactions for WMH volume (pinteraction = 0.016) and MD (pinteraction = 0.037). Voxel-wise analyses also showed that lower Montreal Cognitive Assessment scores were associated with frontal WMH in patients 6480 years, but not >80 years.ConclusionMRI markers of white matter damage are strongly related to cognition in patients with TIA/minor stroke at younger ages, but not at age >80 years. Clinicians and patients should not overinterpret the significance of these abnormalities at older ages

Care pathways in older patients seen in a multidisciplinary same day emergency care (SDEC) unit

Background: Same day emergency care (SDEC) services are being advocated in the UK for frail, older patients in whom hospitalisation may be associated with harm but there are few data on the ‘ambulatory pathway’. We therefore determined the patient pathways pre- and post-first assessment in a SDEC unit focussed on older people. Methods: In consecutive patients, we prospectively recorded follow-up SDEC service reviews (face-to-face, telephone, Hospital-at-Home domiciliary visits), outpatient referrals (e.g. to specialist clinics, imaging, and community/voluntary/social services), and hospital admissions <30 days. In the first 67 patients, we also recorded healthcare interactions (except GP attendances) in the 180 days pre- and post-first assessment. Results: Among 533 patients (mean/SD age = 75.0/17.5 years, 246, 46% deemed frail) assessed in an SDEC unit, 210 were admitted within 30 days (152 immediately). In the 381(71%) remaining initially ambulatory, there were 587 SDEC follow-up reviews and 747 other outpatient referrals (mean = 3.5 per patient) with only 34 (9%) patients being discharged with no further follow-up. In the subset (n = 67), the number of ‘healthcare days’ was greater in the 180 days post- versus pre-SDEC assessment (mean/SD = 26/27 versus 13/22 days, P = 0.003) even after excluding hospital admission days, with greater healthcare days in frail versus non-frail patients. Discussion and Conclusion: SDEC assessment in older, frail patients was associated with a 2-fold increase in frequency of healthcare interactions with complex care pathways involving multiple services. Our findings have implications for the development of admission-avoidance models including cost-effectiveness and optimal delivery of the multi-dimensional aspects of acute geriatric care in the ambulatory setting

Quasielastic scattering in the interaction of ultracold neutrons with a liquid wall and application in a reanalysis of the Mambo I neutron-lifetime experiment

We develop a theory of ultracold and very cold neutron scattering on viscoelastic surface waves up to second-order perturbation theory. The results are applied to reanalyze the 1989 neutron-lifetime experiment using ultracold neutron storage in a Fomblin-coated vessel by Mampe et al. [Phys. Rev. Lett. 63, 593 (1989)]. Inclusion of this theory of the quasielastic scattering process in the data analysis shifts the neutron lifetime value from 887.6 ± 3 to 882.5 ± 2.1 s

Geometric-phase-induced false electric dipole moment signals for particles in traps

Theories are developed to evaluate Larmor frequency shifts, derived from geometric phases, in experiments to measure electric dipole moments (EDMs) of trapped, atoms, molecules and neutrons. A part of these shifts is proportional to the applied electric field and can be interpreted falsely as an electric dipole moment. A comparison is made between our theoretical predictions for these shifts and some results from our recent experiments, which shows agreement to within the experimental errors of 15 %. The comparison also demonstrates that some trapped particle EDM experiments have reached the sensitivity where stringent precautions are needed to minimise and control such false EDMs. Computer simulations of these processes are also described. They give good agreement with the analytical results and they extend the study by investigating the influence of varying surface reflection laws in the hard walled traps considered. They also explore the possibility to suppress such false EDMs by introducing collisions with buffer gas particles. Some analytic results for frequency shifts proportional to the square of the E-field are also given and there are results for the averaging of the B-field in the absence of an E-field