Incidence and costs of unintentional falls in older people in the United Kingdom

STUDY OBJECTIVE: To estimate the number of accident and emergency (A&E) attendances, admissions to hospital, and the associated costs as a result of unintentional falls in older people. DESIGN: Analysis of national databases for cost of illness. SETTING: United Kingdom, 1999, cost to the National Health Service (NHS) and Personal Social Services (PSS). PARTICIPANTS: Four age groups of people 60 years and over (60–64, 65–69, 70–74, and 75) attending an A&E department or admitted to hospital after an unintentional fall. Databases analysed were the Home Accident Surveillance System (HASS) and Leisure Accident Surveillance System (LASS), and Hospital Episode Statistics (HES). MAIN RESULTS: There were 647 721 A&E attendances and 204 424 admissions to hospital for fall related injuries in people aged 60 years and over. For the four age groups A&E attendance rates per 10 000 population were 273.5, 287.3, 367.9, and 945.3, and hospital admission rates per 10 000 population were 34.5, 52.0, 91.9, and 368.6. The cost per 10 000 population was £300 000 in the 60–64 age group, increasing to £1 500 000 in the 75 age group. These falls cost the UK government £981 million, of which the NHS incurred 59.2%. Most of the costs (66%) were attributable to falls in those aged 75 years. The major cost driver was inpatient admissions, accounting for 49.4% of total cost of falls. Long term care costs were the second highest, accounting for 41%, primarily in those aged 75 years. CONCLUSIONS: Unintentional falls impose a substantial burden on health and social services

Asteroseismology of red giants: photometric observations of Arcturus by SMEI

We present new results on oscillations of the K1.5 III giant Arcturus (alpha Boo), from analysis of just over 2.5 yr of precise photometric observations made by the Solar Mass Ejection Imager (SMEI) on board the Coriolis satellite. A strong mode of oscillation is uncovered by the analysis, having frequency 3.51+/-0.03 micro-Hertz. By fitting its mode peak, we are able offer a highly constrained direct estimate of the damping time (tau = 24+/-1 days). The data also hint at the possible presence of several radial-mode overtones, and maybe some non-radial modes. We are also able to measure the properties of the granulation on the star, with the characteristic timescale for the granulation estimated to be 0.50+/-0.05 days.Comment: 6 pages, 5 figures; accepted for publication in MNRAS Letter

A thorough analysis of the short- and mid-term activity-related variations in the solar acoustic frequencies

The frequencies of the solar acoustic oscillations vary over the activity cycle. The variations in other activity proxies are found to be well correlated with the variations in the acoustic frequencies. However, each proxy has a slightly different time behaviour. Our goal is to characterize the differences between the time behaviour of the frequency shifts and of two other activity proxies, namely, the area covered by sunspots and the 10.7cm flux. We define a new observable that is particularly sensitive to the short-term frequency variations. We then compare the observable when computed from model frequency shifts and from observed frequency shifts obtained with the Global Oscillation Network Group (GONG) for cycle 23. Our analysis shows that on the shortest time-scales the variations in the frequency shifts seen in the GONG observations are strongly correlated with the variations in the area covered by sunspots. However, a significant loss of correlation is still found. We verify that the times when the frequency shifts and the sunspot area do not vary in a similar way tend to coincide with the times of the maxima of the quasi-biennial variations seen in the solar seismic data. A similar analysis of the relation between the 10.7cm flux and the frequency shifts reveals that the short-time variations in the frequency shifts follow even more closely those of the 10.7cm flux than those of the sunspot area. However, a loss of correlation between frequency shifts and 10.7cm flux variations is still found around the same times.Comment: 7 pages, 6 figures, accepted for publication in MNRA

The Octave (Birmingham - Sheffield Hallam) automated pipeline for extracting oscillation parameters of solar-like main-sequence stars

The number of main-sequence stars for which we can observe solar-like oscillations is expected to increase considerably with the short-cadence high-precision photometric observations from the NASA Kepler satellite. Because of this increase in number of stars, automated tools are needed to analyse these data in a reasonable amount of time. In the framework of the asteroFLAG consortium, we present an automated pipeline which extracts frequencies and other parameters of solar-like oscillations in main-sequence and subgiant stars. The pipeline uses only the timeseries data as input and does not require any other input information. Tests on 353 artificial stars reveal that we can obtain accurate frequencies and oscillation parameters for about three quarters of the stars. We conclude that our methods are well suited for the analysis of main-sequence stars, which show mainly p-mode oscillations.Comment: accepted by MNRA

Tests of the asymptotic large frequency separation of acoustic oscillations in solar-type and red giant stars

Asteroseismology, i.e. the study of the internal structures of stars via their global oscillations, is a valuable tool to obtain stellar parameters such as mass, radius, surface gravity and mean density. These parameters can be obtained using certain scaling relations which are based on an asymptotic approximation. Usually the observed oscillation parameters are assumed to follow these scaling relations. Recently, it has been questioned whether this is a valid approach, i.e., whether the order of the observed oscillation modes are high enough to be approximated with an asymptotic theory. In this work we use stellar models to investigate whether the differences between observable oscillation parameters and their asymptotic estimates are indeed significant. We compute the asymptotic values directly from the stellar models and derive the observable values from adiabatic pulsation calculations of the same models. We find that the extent to which the atmosphere is included in the models is a key parameter. Considering a larger extension of the atmosphere beyond the photosphere reduces the difference between the asymptotic and observable values of the large frequency separation. Therefore, we conclude that the currently suggested discrepancies in the scaling relations might have been overestimated. Hence, based on the results presented here we believe that the suggestions of Mosser et al. (2013) should not be followed without careful consideration.Comment: 6 pages, 4 figures, 1 table, accepted for publication by MNRAS as a Letter to the Edito

Analysis of the solar cycle and core rotation using 15 years of Mark-I observations:1984-1999. I. The solar cycle

High quality observations of the low-degree acoustic modes (p-modes) exist for almost two complete solar cycles using the solar spectrophotometer Mark-I, located at the Observatorio del Teide (Tenerife, Spain) and operating now as part of the Birmingham Solar Oscillations Network (BiSON). We have performed a Fourier analysis of 30 calibrated time-series of one year duration covering a total period of 15 years between 1984 and 1999. Applying different techniques to the resulting power spectra, we study the signature of the solar activity changes on the low-degree p-modes. We show that the variation of the central frequencies and the total velocity power (TVP) changes. A new method of simultaneous fit is developed and a special effort has been made to study the frequency-dependence of the frequency shift. The results confirm a variation of the central frequencies of acoustic modes of about 450 nHz, peak-to-peak, on average for low degree modes between 2.5 and 3.7 mHz. The TVP is anti-correlated with the common activity indices with a decrease of about 20% between the minimum and the maximum of solar cycle 22. The results are compared with those obtained for intermediate degrees, using the LOWL data. The frequency shift is found to increase with the degree with a weak l-dependence similar to that of the inverse mode mass. This verifies earlier suggestions that near surface effects are predominant.Comment: Accepted by A&A October 3 200

Asteroseismic surface gravity for evolved stars

Context: Asteroseismic surface gravity values can be of importance in determining spectroscopic stellar parameters. The independent log(g) value from asteroseismology can be used as a fixed value in the spectroscopic analysis to reduce uncertainties due to the fact that log(g) and effective temperature can not be determined independently from spectra. Since 2012, a combined analysis of seismically and spectroscopically derived stellar properties is ongoing for a large survey with SDSS/APOGEE and Kepler. Therefore, knowledge of any potential biases and uncertainties in asteroseismic log(g) values is now becoming important. Aims: The seismic parameter needed to derive log(g) is the frequency of maximum oscillation power (nu_max). Here, we investigate the influence of nu_max derived with different methods on the derived log(g) values. The large frequency separation between modes of the same degree and consecutive radial orders (Dnu) is often used as an additional constraint for the determination of log(g). Additionally, we checked the influence of small corrections applied to Dnu on the derived values of log(g). Methods We use methods extensively described in the literature to determine nu_max and Dnu together with seismic scaling relations and grid-based modeling to derive log(g). Results: We find that different approaches to derive oscillation parameters give results for log(g) with small, but different, biases for red-clump and red-giant-branch stars. These biases are well within the quoted uncertainties of ~0.01 dex (cgs). Corrections suggested in the literature to the Dnu scaling relation have no significant effect on log(g). However somewhat unexpectedly, method specific solar reference values induce biases of the order of the uncertainties, which is not the case when canonical solar reference values are used.Comment: 8 pages, 5 figures, accepted for publication by A&

Changes in the sensitivity of solar p-mode frequency shifts to activity over three solar cycles

Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode frequency to solar activity levels may be different in different cycles. In order to check whether such changes can also be seen at higher degrees, we compare the response of medium-degree solar p-modes to activity levels across three solar cycles using data from Big Bear Solar Observatory (BBSO), Global Oscillation Network Group (GONG), Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI), by examining the shifts in the mode frequencies and their sensitivity to solar activity levels. We compare these shifts and sensitivities with those from radial modes from BiSON. We find that the medium-degree data show small but significant systematic differences between the cycles, with solar cycle 24 showing a frequency shift about 10 per cent larger than cycle 23 for the same change in activity as determined by the 10.7 cm radio flux. This may support the idea that there have been changes in the magnetic properties of the shallow subsurface layers of the Sun that have the strongest influence on the frequency shifts.Comment: 6 pages, 3 figures, accepted by MNRAS 3rd July 201