Context. One of the most unusual aspects of the X-ray binary LS I +61°303 is that at each orbit (P1 = 26.4960 ± 0.0028 d) one radio outburst occurs whose amplitude is modulated with Plong, a ...long-term period of more than 4 yr. It is still not clear whether the compact object of the system or the companion Be star is responsible for the long-term modulation. Aims. We study here the stability of Plong. Such a stability is expected if Plong is due to periodic (P2) Doppler boosting of periodic (P1) ejections from the accreting compact object of the system. On the contrary it is not expected if Plong is related to variations in the mass loss of the companion Be star. Methods. We built a database of 36.8 yr of radio observations of LS I +61°303 covering more than 8 long-term cycles. We performed timing and correlation analysis. We also compared the results of the analyses with the theoretical predictions for a synchrotron emitting precessing (P2) jet periodically (P1) refilled with relativistic electrons. Results. In addition to the two dominant features at P1 and P2, the timing analysis gives a feature at Plong = 1628 ± 48 days. The determined value of Plong agrees with the beat of the two dominant features, i.e. Pbeat = 1 / (ν1−ν2) = 1626 ± 68 d. Lomb-Scargle results of radio data and model data compare very well. The correlation coefficient of the radio data oscillates at multiples of Pbeat, as does the correlation coefficient of the model data. Conclusions. Cycles in varying Be stars change in length and disappear after 2-3 cycles following the well-studied case of the binary system ζ Tau. On the contrary, in LS I +61°303 the long-term period is quite stable and repeats itself over the available 8 cycles. The long-term modulation in LS I +61°303 accurately reflects the beat of periodical Doppler boosting (induced by precession) with the periodicity of the ejecta. The peak of the long-term modulation occurs at the coincidence of the maximum number of ejected particles with the maximum Doppler boosting of their emission; this coincidence occurs every \hbox{$\frac{1}{\nu_1 - \nu_2}$}1ν1−ν2 and creates the long-term modulation observed in LS I +61°303.
Maternal hepatitis B e Antigen (HBeAg) positivity poses a risk for hepatitis B virus (HBV) mother‐to‐child transmission (MTCT). In resource‐constrained settings, HBeAg testing is recommended as an ...alternative to HBV DNA testing to establish antiviral prophylaxis eligibility. Nevertheless, the high prevalence of HBeAg‐negative chronic hepatitis B (e‐CHB) in many countries should not be overlooked. We studied HBV characteristics and explored the potential MTCT risk among HBeAg‐negative/HBsAg‐positive expectant mothers in an area prevalent of e‐CHB. Among 1348 pregnant mothers screened for HBV infection, 81 (6.0%) were HBsAg‐positive. These women were examined for HBeAg, HBV DNA, and cord blood HBV DNA. Sixteen (19.8%) of the HBsAg‐positive mothers were HBeAg‐positive, whereas 65 (80.2%) were HBeAg‐negative, including eight inactive carriers (HBsAg <100 IU/ml, HBV DNA ≤ 2000 IU/ml, and ALT < 40 IU/L). Of the remaining 57 HBeAg‐negative mothers, ten revealed HBV Basal Core Promoter or Precore mutations, with three having high viremia (HBV DNA > 200 000 IU/mL), which is associated with a high MTCT risk and therefore qualifies them for antiviral prophylaxis. This pilot study provides a cautionary note to the interpretation of negative HBeAg test results when determining eligibility for MTCT antiviral prophylaxis in situations with limited resources and in regions where e‐CHB is prevalent.
Aims
To select a core list of standard outcomes for diabetes to be routinely applied internationally, including patient‐reported outcomes.
Methods
We conducted a structured systematic review of ...outcome measures, focusing on adults with either type 1 or type 2 diabetes. This process was followed by a consensus‐driven modified Delphi panel, including a multidisciplinary group of academics, health professionals and people with diabetes. External feedback to validate the set of outcome measures was sought from people with diabetes and health professionals.
Results
The panel identified an essential set of clinical outcomes related to diabetes control, acute events, chronic complications, health service utilisation, and survival that can be measured using routine administrative data and/or clinical records. Three instruments were recommended for annual measurement of patient‐reported outcome measures: the WHO Well‐Being Index for psychological well‐being; the depression module of the Patient Health Questionnaire for depression; and the Problem Areas in Diabetes scale for diabetes distress. A range of factors related to demographic, diagnostic profile, lifestyle, social support and treatment of diabetes were also identified for case‐mix adjustment.
Conclusions
We recommend the standard set identified in this study for use in routine practice to monitor, benchmark and improve diabetes care. The inclusion of patient‐reported outcomes enables people living with diabetes to report directly on their condition in a structured way.
What's new?
Standardized monitoring of diabetes care can improve quality through routine audit and benchmarking. Inconsistencies between measures adopted in different countries hamper this process and undermine international comparisons.
This study was the first multinational effort to recommend a standard list of outcomes that matter most to people with diabetes, and that can be used in routine clinical practice to monitor, benchmark and improve diabetes care.
The essential outcomes relate to diabetes control, acute events, chronic complications, health service utilisation and survival, measured using routine administrative data and/or clinical records. Three instruments were recommended for annual measurement of patient‐reported outcome measures (PROMs): the WHO Well‐Being Index for psychological well‐being; the depression module of the Patient Health Questionnaire for depression; and the Problem Areas in Diabetes scale for diabetes distress.
The black hole candidate LS I +61°303 Massi, M; Migliari, S; Chernyakova, M
Monthly Notices of the Royal Astronomical Society,
07/2017, Letnik:
468, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Abstract
In recent years, fundamental relationships for the black hole X-ray binaries have been established between their X-ray luminosity L
X and the photon index Γ of their X-ray spectrum. For the ...moderate-luminosity regime, an anticorrelation between Γ and L
X has been observed. In this paper, aimed to verify if the moderate luminous X-ray binary system LS I +61°303 is a black hole, we analyse Swift observations of LS I +61°303. We compare the derived L
X versus Γ distribution, first with the statistical trend for black hole X-ray binaries, then with the trend of the pulsar PSR B1259−63 and finally with the individual trends of the black hole X-ray binaries Swift J1357.2−0933 and V404 Cygni. We find that the system PSR B1259−63 shows a positive correlation between Γ and L
X, whereas in contrast LS I +61°303 shows the same anticorrelation as for black hole X-ray binaries. Moreover, the trend of LS I +61°303 in the L
X/L
Eddington–Γ plane overlaps with that of the two black holes Swift J1357.2−0933 and V404 Cygni. All three systems, Swift J1357.2−0933, V404 Cygni and LS I +61°303 well trace the last part of the evolution of accreting black holes at moderate luminosity until their drop to quiescence.
Aims. Our aim is to show how variable Doppler boosting of an intrinsically variable jet can explain the long-term modulation of 1667 ± 8 days observed in the radio emission of LS I +61°303. Methods. ...The physical scenario is that of a conical, magnetized plasma jet having a periodical (P1) increase of relativistic particles, Nrel, at a specific orbital phase, as predicted by accretion in the eccentric orbit of LS I +61°303. Jet precession (P2) changes the angle, η, between jet axis and line of sight, thereby inducing variable Doppler boosting. The problem is defined in spherical geometry, and the optical depth through the precessing jet is calculated by taking into account that the plasma is stratified along the jet axis. The synchrotron emission of such a jet was calculated and we fitted the resulting flux density Smodel(t) to the observed flux density obtained during a 6.5-year monitoring of LS I +61°303 by the Green Bank radio interferometer. Results. Our physical model for the system LS I +61°303 is not only able to reproduce the long-term modulation in the radio emission, but it also reproduces all the other observed characteristics of the radio source, the orbital modulation of the outbursts, their orbital phase shift, and their spectral index properties. Moreover, a correspondence seems to exist between variations in the ejection angle induced by precession and the rapid rotation in position angle observed in VLBA images. Conclusions. The peak of the long-term modulation occurs when the jet electron density is around its maximum and the approaching jet is forming the smallest possible angle with the line of sight. This coincidence of maximum number of emitting particles and maximum Doppler boosting of their emission occurs every ~1667 days and creates the long-term modulation observed in LS I +61°303.
Context. In the binary system LS I +61°303 the peak flux density of the radio outburst, which is related to the orbital period of 26.4960 ± 0.0028d, exibits a modulation of 1667 ± 8 d. The radio ...emission at high spatial resolution appears structured in a precessing jet with a precessional period of 27−28 d. Aims. How close is the precessional period of the radio jet to the orbital period? Any periodicity in the radio emission should be revealed by timing analysis. The aim of this work is to establish the accurate value of the precessional period. Methods. We analyzed 6.7 years of the Green Bank Interferometer database at 2.2 GHz and 8.3 GHz with the Lomb-Scargle and phase dispersion minimization methods and performed simulations. Results. The periodograms show two periodicities, P1 = 26.49 ± 0.07d (ν1 = 0.03775 d-1) and P2 = 26.92 ± 0.07d (ν2 = 0.03715 d-1). Whereas radio outbursts have been known to have nearly orbital occurrence P1 with timing residuals exhibiting a puzzling sawtooth pattern, we probe in this paper that they are actually periodical outbursts and that their period is Paverage = 2/(ν1 + ν2) = 26.70 ± 0.05 d. The period Paverage as well as the long-term modulation Pbeat = 1/(ν1 − ν2) = 1667 ± 393 d result from the beat of the two close periods, the orbital P1 and the precessional P2 periods. Conclusions. The precessional period, indicated by the astrometry to be of 27–28 d, is P2 = 26.92 d. The system LS I +61°303 seems to be one more case in astronomy of beat, i.e., a phenomenon occurring when two physical processes create stable variations of nearly equal frequencies. The very small difference in frequency creates a long-term variation of period 1/(ν1 − ν2). The long-term modulation of 1667 d results from the beat of the two close orbital and precessional rates.
The second Diabetes Attitudes, Wishes and Needs (DAWN2) study sought cross-national comparisons of perceptions on healthcare provision for benchmarking and sharing of clinical practices to improve ...diabetes care.
In total, 4785 healthcare professionals caring for people with diabetes across 17 countries participated in an online survey designed to assess diabetes healthcare provision, self-management and training.
Between 61.4 and 92.9% of healthcare professionals felt that people with diabetes needed to improve various self-management activities; glucose monitoring (range, 29.3-92.1%) had the biggest country difference, with a between-country variance of 20%. The need for a major improvement in diabetes self-management education was reported by 60% (26.4-81.4%) of healthcare professionals, with a 12% between-country variance. Provision of diabetes services differed among countries, with many healthcare professionals indicating that major improvements were needed across a range of areas, including healthcare organization 30.6% (7.4-67.1%), resources for diabetes prevention 78.8% (60.4-90.5%), earlier diagnosis and treatment 67.9% (45.0-85.5%), communication between team members and people with diabetes 56.1% (22.3-85.4%), specialist nurse availability 63.8% (27.9-90.7%) and psychological support 62.7% (40.6-79.6%). In some countries, up to one third of healthcare professionals reported not having received any formal diabetes training. Societal discrimination against people with diabetes was reported by 32.8% (11.4-79.6%) of participants.
This survey has highlighted concerns of healthcare professionals relating to diabetes healthcare provision, self-management and training. Identifying between-country differences in several areas will allow benchmarking and sharing of clinical practices.
Aim: To estimate absolute and relative incidence rates of hypoglycaemia when using once-daily evening or morning regimens of insulin glargine (glargine) versus once-daily evening NPH insulin (NPH) ...using individual patient data (IPD). Materials and methods: Randomized controlled trials with accessible IPD and including white European people with type 2 diabetes (T2DM) using glargine or NPH once-daily (with oral glucose-lowering drugs) were identified. Two study pools were analysed: evening glargine versus evening NPH (pool 1); and morning glargine versus evening NPH (pool 2). The number-needed-to-treat to avoid hypoglycaemia was calculated for glargine versus NPH. Results: In study pool 1 (n = 2711), the risk of nocturnal hypoglycaemia was approximately halved with glargine compared with NPH odds ratios (OR): 0.44-0.52, p < 0.001-0.047. This led to a significant reduction in anytime risk of symptomatic hypoglycaemia plasma glucose (PG) <3.9 mmol/l, OR: 0.64, p = 0.018; PG <2.0 mmol/l, OR: 0.51, p < 0.001. In study pool 2 (n = 470), although a strong numerical reduction in all types of nocturnal hypoglycaemia was observed (OR: 0.16-0.64), statistical significance was reached only for symptomatic hypoglycaemia with PG <3.9 mmol/l (p < 0.001). Eight (pool 1) or five (pool 2) people with T2DM needed to use glargine rather than NPH to avoid one person from experiencing a nocturnal symptomatic hypoglycaemic event within a median of about 25 weeks of starting insulin. Conclusions: This meta-analysis of open-label studies provides confidence that reductions of around 50% of risk for nocturnal hypoglycaemia can be achieved with using glargine instead of NPH.
Aims. The aim of this paper is to analyse the previously discovered discontinuity of the periodicity of the GeV γ-ray emission of the radio-loud X-ray binary LS I + 61°303 and to determine its ...physical origin. Methods. We used a wavelet analysis to explore the temporal development of periodic signals. The wavelet analysis was first applied to the whole data set of available Fermi-LAT data and then to the two subsets of orbital phase intervals Φ = 0.0−0.5 and Φ = 0.5−1.0. We also performed a Lomb-Scargle timing analysis. We investigated the similarities between GeV γ-ray emission and radio emission by comparing the folded curves of the Fermi-LAT data and the Green Bank Interferometer radio data. Results. During the epochs when the timing analysis fails to determine the orbital periodicity, the periodicity is present in the two orbital phase intervals Φ = 0.0−0.5 and Φ = 0.5−1.0. That is, there are two periodical signals, one towards periastron (i.e., Φ = 0.0−0.5) and another one towards apoastron (Φ = 0.5−1.0). The apoastron peak seems to be affected by the same orbital shift as the radio outbursts and, in addition, reveals the same two periods P1 and P2 that are present in the radio data. Conclusions. The γ-ray emission of the apoastron peak normally just broadens the emission of the peak around periastron. Only when it appears at Φ ≈ 0.8−1.0 because of the orbital shift, it is enough detached from the first peak to become recognisable as a second orbital peak, which is the reason why the timing analysis fails. Two γ-ray peaks along the orbit are predicted by the two-peak accretion model for an eccentric orbit that was proposed by several authors for LS I + 61°303.
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