17 research outputs found
Parallax of OGLE-2018-BLG-0596: A Low-mass-ratio Planet around an M-dwarf
We report the discovery of a microlensing planet
OGLE-2018-BLG-0596Lb, with preferred planet-host mass ratio . The planetary signal, which is characterized by a short "bump" on the rising side of the lensing light curve, was densely
covered by ground-based surveys. We find that the signal can be explained by a
bright source that fully envelops the planetary caustic, i.e., a "Hollywood"
geometry. Combined with the source proper motion measured from , the
satellite parallax measurement makes it possible to precisely
constrain the lens physical parameters. The preferred solution, in which the
planet perturbs the minor image due to lensing by the host, yields a
Uranus-mass planet with a mass of orbiting
a mid M-dwarf with a mass of . There is also
a second possible solution that is substantially disfavored but cannot be ruled
out, for which the planet perturbs the major image. The latter solution yields
and . By
combining the microlensing and data together with a Galactic model, we
find in either case that the lens lies on the near side of the Galactic bulge
at a distance . Future adaptive optics
observations may decisively resolve the major image/minor image degeneracy.Comment: 34 pages, 8 figures, Submitted to AAS journa
Arthritis prevention in the pre-clinical phase of RA with abatacept (the APIPPRA study): a multi-centre, randomised, double-blind, parallel-group, placebo-controlled clinical trial protocol.
TRIAL DESIGN: We present a study protocol for a multi-centre, randomised, double-blind, parallel-group, placebo-controlled trial that seeks to test the feasibility, acceptability and effectiveness of a 52-week period of treatment with the first-in-class co-stimulatory blocker abatacept for preventing or delaying the onset of inflammatory arthritis. METHODS: The study aimed to recruit 206 male or female subjects from the secondary care hospital setting across the UK and the Netherlands. Participants who were at least 18 years old, who reported inflammatory sounding joint pain (clinically suspicious arthralgia) and who were found to be positive for serum autoantibodies associated with rheumatoid arthritis (RA) were eligible for enrolment. All study subjects were randomly assigned to receive weekly injections of investigational medicinal product, either abatacept or placebo treatment over the course of a 52-week period. Participants were followed up for a further 52 weeks. The primary endpoint was defined as the time to development of at least three swollen joints or to the fulfilment of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for RA using swollen but not tender joints, whichever endpoint was met first. In either case, swollen joints were confirmed by ultrasonography. Participants, care givers, and those assessing the outcomes were all blinded to group assignment. Clinical assessors and ultrasonographers were also blinded to each other's assessments for the duration of the study. CONCLUSIONS: There is limited experience of the design and implementation of trials for the prevention of inflammatory joint diseases. We discuss the rationale behind choice and duration of treatment and the challenges associated with defining the "at risk" state and offer pragmatic solutions in the protocol to enrolling subjects at risk of RA. TRIAL REGISTRATION: Current Controlled Trials, ID: ISRCTN46017566 . Registered on 4 July 2014
Why do banks promise to pay par on demand?
We survey the theories of why banks promise to pay par on demand and examine evidence about
the conditions under which banks have promised to pay the par value of deposits and banknotes on
demand when holding only fractional reserves. The theoretical literature can be broadly divided into four
strands: liquidity provision, asymmetric information, legal restrictions, and a medium of exchange. We
assume that it is not zero cost to make a promise to redeem a liability at par value on demand. If so, then
the conditions in the theories that result in par redemption are possible explanations of why banks
promise to pay par on demand. If the explanation based on customers’ demand for liquidity is correct,
payment of deposits at par will be promised when banks hold assets that are illiquid in the short run. If
the asymmetric-information explanation based on the difficulty of valuing assets is correct, the
marketability of banks’ assets determines whether banks promise to pay par. If the legal restrictions
explanation of par redemption is correct, banks will not promise to pay par if they are not required to do
so. If the transaction explanation is correct, banks will promise to pay par value only if the deposits are
used in transactions. After the survey of the theoretical literature, we examine the history of banking in
several countries in different eras: fourth-century Athens, medieval Italy, Japan, and free banking and
money market mutual funds in the United States. We find that all of the theories can explain some of the
observed banking arrangements, and none explain all of them
Systematic KMTNet Planetary Anomaly Search. V. Complete Sample of 2018 Prime-Field
We complete the analysis of all 2018 prime-field microlensing planets
identified by the KMTNet AnomalyFinder. Among the 10 previously unpublished
events with clear planetary solutions, 8 are either unambiguously planetary or
are very likely to be planetary in nature: OGLE-2018-BLG-1126,
KMT-2018-BLG-2004, OGLE-2018-BLG-1647, OGLE-2018-BLG-1367, OGLE-2018-BLG-1544,
OGLE-2018-BLG-0932, OGLE-2018-BLG-1212, and KMT-2018-BLG-2718. Combined with
the 4 previously published new AnomalyFinder events and 12 previously published
(or in preparation) planets that were discovered by eye, thismakes a total of
24 2018 prime-field planets discovered or recovered by AnomalyFinder. Together
with a paper in preparation on 2018 sub-prime planets, this work lays the basis
for the first statistical analysis of the planet mass-ratio function based on
planets identified in KMTNet data. By systematically applying the heuristic
analysis of Hwang et al. (2022) to each event, we identify the small
modification in their formalism that is needed to unify the so-called
close/wide and inner/outer degeneracies, as conjectured byComment: 22 pages, 14 tables, 15 figure
OGLE-2018-BLG-1011L\lowercase{b,c}: Microlensing Planetary System with Two Giant Planets Orbiting a Low-mass Star
We report a multiplanetary system found from the analysis of microlensing
event OGLE-2018-BLG-1011, for which the light curve exhibits a double-bump
anomaly around the peak. We find that the anomaly cannot be fully explained by
the binary-lens or binary-source interpretations and its description requires
the introduction of an additional lens component. The 3L1S (3 lens components
and a single source) modeling yields three sets of solutions, in which one set
of solutions indicates that the lens is a planetary system in a binary, while
the other two sets imply that the lens is a multiplanetary system. By
investigating the fits of the individual models to the detailed light curve
structure, we find that the multiple-planet solution with planet-to-host mass
ratios and are favored over
the other solutions. From the Bayesian analysis, we find that the lens is
composed of two planets with masses and
around a host with a mass
and located at a distance
. The estimated distance indicates that the lens
is the farthest system among the known multiplanetary systems. The projected
planet-host separations are
() and ,
where the values of in and out the parenthesis are the
separations corresponding to the two degenerate solutions, indicating that both
planets are located beyond the snow line of the host, as with the other four
multiplanetary systems previously found by microlensing.Comment: 14 pages, 18 figures, 8 table
Temporal changes in home advantage in English football since the Second World War: what explains improved away performance?
This study examined temporal trends in home advantage in the top two English football divisions and used change point analysis to test the hypothesis that home advantage has not remained constant over time. Regression analysis was used to model the impact of substitutions (a proxy for "information transfer") and the points system on home advantage. The results suggest that changing from two points for a win to three points for a win has led to a 0.39 reduction (95% confidence interval=0.21 to 0.56) in the ratio of home wins to away wins. Increasing the number of substitutions is associated with a small increase in the ratio of home wins to away wins, although this is not statistically significant. The evidence indicates that, in this particular context, the extent of home advantage has diminished. This contradicts most other published work, which suggests that home advantage is stable over time. I argue that this reduction is more likely to be the result of the introduction of three points for a win, which has lessened the incentives for away teams to settle for a draw, than an increase in "information transfer". Research into temporal trends in home advantage is interesting in its own right but might, in addition, shed light on determinants of the home advantage phenomenon
Cost-effectiveness of preoperative positron emission tomography in ischemic heart disease.
BACKGROUND: Revascularization of patients with ischemic heart disease and poor left ventricular function for surgical procedures is expensive and carries considerable risks, but may improve survival for patients with hibernating myocardium. Positron emission tomography can detect hibernating myocardium, and may be cost-effective if used to select patients for operation. METHODS: An economic model was developed to compare the cost-effectiveness of three management strategies: (1) coronary artery bypass grafting for all patients; (2) using positron emission tomography to select candidates for coronary artery bypass grafting, those without hibernation remaining on medical therapy; and (3) medical therapy for all patients. The model used data from our hospital and the published literature. A sensitivity analysis was also undertaken. RESULTS: Positron emission tomography was cost-effective in selecting patients for operation. In a hypothetical population of 1,000 patients, using positron emission tomography saved marginally more life-years and cost approximately Pound Sterling 3 million less. Using positron emission tomography before coronary artery bypass grafting instead of all patients receiving medical treatment saved lives but was more expensive. The incremental cost per life-year saved was Pound Sterling 77,000. The sensitivity analysis showed that the prevalence of hibernation and the survival rate of patients refused revascularization on the basis of the positron emission tomography scan were the areas most likely to influence cost-effectiveness. CONCLUSIONS: Positron emission tomography may be cost-effective to select patients with poor left ventricular function for coronary artery bypass grafting
Design and performance of a multi-centre randomised controlled trial and economic evaluation of joint tele-consultations [ISRCTN54264250]
BACKGROUND: Appropriate information flow is crucial to the care of patients, particularly at the interface between primary and secondary care. Communication problems can result from inadequate organisation and training, There is a major expectation that information and communication technologies may offer solutions, but little reliable evidence. This paper reports the design and performance of a multi-centre randomised controlled trial (RCT), unparalleled in telemedicine research in either scale or range of outcomes. The study investigated the effectiveness and cost implications in rural and inner-city settings of using videoconferencing to perform joint tele-consultations as an alternative to general practitioner referral to the hospital specialist in the outpatient clinic. METHODS: Joint tele-consultation services were established in both the Royal Free Hampstead NHS Trust in inner London, and the Royal Shrewsbury Hospitals Trust, in Shropshire. All the patients who gave consent to participate were randomised either to joint tele-consultation or to a routine outpatients appointment. The principal outcome measures included the frequency of decision by the specialist to offer a follow-up outpatient appointment, patient satisfaction (Ware Specific Questionnaire), wellbeing (SF12) and enablement (PEI), numbers of tests, investigations, procedures and treatments. RESULTS: A total of 134 general practitioners operating from 29 practices participated in the trial, referring a total of 3170 patients to 20 specialists in ENT medicine, general medicine (including endocrinology, and rheumatology), gastroenterology, orthopaedics, neurology and urology. Of these, 2094 patients consented to participate in the study and were correctly randomised. There was a 91% response rate to the initial assessment questionnaires, and analysis showed equivalence for all key characteristics between the treatment and control groups. CONCLUSION: We have designed and performed a major multi-centre trial of teleconsultations in two contrasting centres. Many problems were overcome to enable the trial to be carried out, with a considerable development and learning phase. A lengthier development phase might have enabled us to improve the patient selection criteria, but there is a window of opportunity for these developments, and we believe that our approach was appropriate, allowing the evaluation of the technology before its widespread implementation
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Arthritis prevention in the pre-clinical phase of RA with abatacept (the APIPPRA study): a multi-centre, randomised, double-blind, parallel-group, placebo-controlled clinical trial protocol.
TRIAL DESIGN: We present a study protocol for a multi-centre, randomised, double-blind, parallel-group, placebo-controlled trial that seeks to test the feasibility, acceptability and effectiveness of a 52-week period of treatment with the first-in-class co-stimulatory blocker abatacept for preventing or delaying the onset of inflammatory arthritis. METHODS: The study aimed to recruit 206 male or female subjects from the secondary care hospital setting across the UK and the Netherlands. Participants who were at least 18 years old, who reported inflammatory sounding joint pain (clinically suspicious arthralgia) and who were found to be positive for serum autoantibodies associated with rheumatoid arthritis (RA) were eligible for enrolment. All study subjects were randomly assigned to receive weekly injections of investigational medicinal product, either abatacept or placebo treatment over the course of a 52-week period. Participants were followed up for a further 52 weeks. The primary endpoint was defined as the time to development of at least three swollen joints or to the fulfilment of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for RA using swollen but not tender joints, whichever endpoint was met first. In either case, swollen joints were confirmed by ultrasonography. Participants, care givers, and those assessing the outcomes were all blinded to group assignment. Clinical assessors and ultrasonographers were also blinded to each other's assessments for the duration of the study. CONCLUSIONS: There is limited experience of the design and implementation of trials for the prevention of inflammatory joint diseases. We discuss the rationale behind choice and duration of treatment and the challenges associated with defining the "at risk" state and offer pragmatic solutions in the protocol to enrolling subjects at risk of RA. TRIAL REGISTRATION: Current Controlled Trials, ID: ISRCTN46017566 . Registered on 4 July 2014