Excellent results with the cemented Lubinus SP II 130-mm femoral stem at 10 years of follow-up

Background and purpose - The Lubinus SP II stem is well documented in both orthopedic registries and clinical studies. Worldwide, the most commonly used stem lengths are 150 mm and 170 mm. In 1995, the 130-mm stem was introduced, but no outcome data have been published. We assessed the long-term survival of the Lubinus SP II 130-mm stem in primary total hip arthroplasty.Patients and methods - In a retrospective cohort study, we evaluated 829 patients with a Lubinus SP II primary total hip arthroplasty (932 hips). The hips were implanted between 1996 and 2001. The primary endpoint was revision for any reason. The mean follow-up period was 10 (5-15) years.Results - Survival analysis showed an all-cause 10-year survival rate of the stem of 98.7% (95% CI: 99.7-97.7), and all-cause 10-year survival of the total hip arthroplasty was 98.3% (95% CI: 99.3-97.3).Interpretation - Excellent long-term results can be achieved with the cemented Lubinus SP II with the relatively short 130-mm stem. This stem has potential advantages over its 150-mm and 170-mm siblings such as bone preservation distal to the stem, better proximal filling around the prosthesis, and easier removal.</p

Mass ratio from Doppler beaming and R{\o}mer delay versus ellipsoidal modulation in the Kepler data of KOI-74

We present a light curve analysis and radial velocity study of KOI-74, an eclipsing A star + white dwarf binary with a 5.2 day orbit. Aside from new spectroscopy covering the orbit of the system, we used 212 days of publicly available Kepler observations and present the first complete light curve fitting to these data, modelling the eclipses and transits, ellipsoidal modulation, reflection, and Doppler beaming. Markov Chain Monte Carlo simulations are used to determine the system parameters and uncertainty estimates. Our results are in agreement with earlier studies, except that we find an inclination of 87.0 \pm 0.4\degree, which is significantly lower than the previously published value. We find that the mass ratio derived from the radial velocity amplitude (q=0.104 \pm 0.004) disagrees with that derived from the ellipsoidal modulation (q=0.052 \pm 0.004} assuming corotation). This was found before, but with our smaller inclination, the discrepancy is even larger than previously reported. Accounting for the rapid rotation of the A-star is found to increase the discrepancy even further by lowering the mass ratio to q=0.047 \pm 0.004. These results indicate that one has to be extremely careful in using the amplitude of an ellipsoidal modulation signal in a close binary to determine the mass ratio, when a proof of corotation is not firmly established. The radial velocities that can be inferred from the detected Doppler beaming in the light curve are found to be in agreement with our spectroscopic radial velocity determination. We also report the first measurement of R{\o}mer delay in a light curve of a compact binary. This delay amounts to -56 \pm 17 s and is consistent with the mass ratio derived from the radial velocity amplitude. The firm establishment of this mass ratio at q=0.104 \pm 0.004 leaves little doubt that the companion of KOI-74 is a low mass white dwarf.Comment: 9 pages, 7 figures, 2 tables; accepted for publication in MNRA

Seasonal diet changes in elephant and impala in mopane woodland

Elephant and impala as intermediate feeders, having a mixed diet of grass and browse, respond to seasonal fluctuations of forage quality by changing their diet composition. We tested the hypotheses that (1) the decrease in forage quality is accompanied by a change in diet from more monocots in the wet season to more dicots in the dry season and that that change is more pronounced and faster in impala than in elephant; (2) mopane (Colophospermum mopane), the most abundant dicot species, is the most important species in the elephant diet in mopane woodland, whereas impala feed relatively less on mopane due to the high condensed tannin concentration; and (3) impala on nutrient-rich soils have a diet consisting of more grass and change later to diet of more browse than impala on nutrient-poor soils. The phosphorus content and in vitro digestibility of monocots decreased and the NDF content increased significantly towards the end of the wet season, whereas in dicots no significant trend could be detected. We argue that this decreasing monocot quality caused elephant and impala to consume more dicots in the dry season. Elephant changed their diet gradually over a 16-week period from 70% to 25% monocots, whereas impala changed diets rapidly (2-4 weeks) from 95% to 70% monocots. For both elephants and impala, there was a positive correlation between percentage of monocots and dicots in the diet and the in vitro digestibility of these forage items. Mopane was the most important dicot species in the elephant diet and its contribution to the diet increased significantly in the dry season, whereas impala selected other dicot species. On nutrient-rich gabbroic soils, impala ate significantly more monocots than impala from nutrient-poor granitic soils, which was related to the higher in vitro digestibility of the monocots on gabbroic soil. Digestibility of food items appears to be an important determinant of diet change from the wet to the dry season in impala and elephants

Observation of Sommerfeld precursors on a fluid surface

We report the observation of two types of Sommerfeld precursors (or forerunners) on the surface of a layer of mercury. When the fluid depth increases, we observe a transition between these two precursor surface waves in good agreement with the predictions of asymptotic analysis. At depths thin enough compared to the capillary length, high frequency precursors propagate ahead of the ''main signal'' and their period and amplitude, measured at a fixed point, increase in time. For larger depths, low frequency ''precursors'' follow the main signal with decreasing period and amplitude. These behaviors are understood in the framework of the analysis first introduced for linear transient electromagnetic waves in a dielectric medium by Sommerfeld and Brillouin [1].Comment: to be published in Physical Review Letter

Three ways to solve the orbit of KIC11558725: a 10 day beaming sdB+WD binary with a pulsating subdwarf

The recently discovered subdwarf B (sdB) pulsator KIC11558725 features a rich g-mode frequency spectrum, with a few low-amplitude p-modes at short periods, and is a promising target for a seismic study aiming to constrain the internal structure of this star, and of sdB stars in general. We have obtained ground-based spectroscopic Balmer-line radial-velocity measurements of KIC11558725, spanning the 2010 and 2011 observing seasons. From these data we have discovered that KIC11558725 is a binary with period P=10.05 d, and that the radial-velocity amplitude of the sdB star is 58 km/s. Consequently the companion of the sdB star has a minimum mass of 0.63 M\odot, and is therefore most likely an unseen white dwarf. We analyse the near-continuous 2010-2011 Kepler light curve to reveal orbital Doppler-beaming light variations at the 238 ppm level, which is consistent with the observed spectroscopic orbital radial-velocity amplitude of the subdwarf. We use the strongest 70 pulsation frequencies in the Kepler light curve of the subdwarf as clocks to derive a third consistent measurement of the orbital radial-velocity amplitude, from the orbital light-travel delay. We use our high signal-to-noise average spectra to study the atmospheric parameters of the sdB star, deriving Teff = 27 910K and log g = 5.41 dex, and find that carbon, nitrogen and oxygen are underabundant relative to the solar mixture. Furthermore, we extract more than 160 significant frequencies from the Kepler light curve. We investigate the pulsation frequencies for expected period spacings and rotational splittings. We find period-spacing sequences of spherical-harmonic degrees \ell=1 and \ell=2, and we associate a large fraction of the g-modes in KIC11558725 with these sequences. From frequency splittings we conclude that the subdwarf is rotating subsynchronously with respect to the orbit

Relations Between Timing Features and Colors in Accreting Millisecond Pulsars

We have studied the aperiodic X-ray timing and color behavior of the accreting millisecond pulsars SAX J1808.4-3658, XTE J1751-305, XTE J0929-314, and XTE J1814-338 using large data sets obtained with the Rossi X-ray Timing Explorer. We find that the accreting millisecond pulsars have very similar timing properties to the atoll sources and the low luminosity bursters. Based on the correlation of timing and color behavior SAX J1808.4-3658 can be classified as an atoll source, and XTE J0929-314 and XTE J1814-338 are consistent with being atoll sources, but the color behavior of XTE J1751-305 is different. Unlike in other atoll sources the hard color in the extreme island state of XTE J1751-305 is strongly correlated with soft color and intensity, and is not anti-correlated with any of the characteristic frequencies. We found previously, that the frequencies of the variability components of atoll sources follow a universal scheme of correlations. The frequency correlations of the accreting millisecond pulsars are similar, but in the case of SAX J1808.4-3658 and XTE J0929-314 shifted compared to those of the other atoll sources in a way that is most easily described as a shift in upper and lower kilohertz QPO frequency by a factor close to 1.5. Although, we note that the shift in lower kilohertz QPO frequency is based on only one observation for SAX J1808.4-3658. XTE J1751-305 and XTE J1814-338, as well as the low luminosity bursters show no or maybe small shifts.Comment: 46 pages, 23 figures, ApJ accepte

How well do healthcare professionals know of the priorities of their older patients regarding treatment outcomes?

OBJECTIVES: For shared decision making, it is crucial to identify patients' priorities regarding health outcomes. Our aim was to study whether healthcare professionals know these priorities. METHODS: In this cross-sectional study we included older patients who had to make a treatment decision, their general practitioners (GPs) and their medical specialists. Agreement between the patients' main health outcome as prioritised by using the Outcome Prioritization Tool (OPT) and the perception of the same outcome by their healthcare professionals. RESULTS: Eighty-seven patients were included. Median age was 76 years, 87.4% of patients presented with malignant disease. The majority prioritised maintaining independence (51.7%), followed by extending life (27.6%). The agreement between patients and healthcare professionals was low (GPs 41.7%, kappa 0.067, p = 0.39), medical specialists 40.3%, kappa 0.074, p = 0.33). Positively related to agreement was patient's age > 75, and a longer relation with their patients (for GPs), and the patient having no partner (for medical specialist). Having a malignant disease, dependent living and functional deficits were negatively related to agreement. CONCLUSIONS: Healthcare professionals have poor perceptions of their patients' priorities. PRACTICE IMPLICATIONS: To realise patient-centered care, it is crucial to discuss priorities explicitly with all patients

Never injected, but hepatitis C virus-infected: a study among self-declared never-injecting drug users from the Amsterdam Cohort Studies

The aim of this study was to gain insight in transmission routes of hepatitis C virus (HCV) infection among never-injecting drug users (DU) by studying, incidence, prevalence, determinants and molecular epidemiology of HCV infection. From the Amsterdam Cohort Studies among DU, 352 never-injecting DU were longitudinally tested for HCV antibodies. Logistic regression was used to identify factors associated with antibody prevalence. Part of HCV NS5B was sequenced to determine HCV genotype and for phylogenetic analyses, in which sequences were compared with those from injecting DU. HCV antibody prevalence was 6.3% and HCV incidence was 0.49/1000 PY. HIV-positive status, female sex and starting injection drug use during follow-up (a putative marker of past injection drug use), were independently associated with HCV prevalence. The main genotypes found were genotype 3a (50%) and 1a (30%). Phylogenetic analysis revealed that HCV strains in never-injecting DU did not cluster together and did not differ from HCV strains circulating in injecting DU. We found a higher HCV prevalence in never-injecting DU than in the general population. Phylogenetic analysis shows a strong link with the injecting DU population. The increased risk could be related to underreporting of injecting drug use or to household or sexual transmission from injectors to noninjectors. Our findings stress the need for HCV testing of DU who report never injecting, especially given the potential to treat HCV infection effectively