1,590 research outputs found
UBVRI photopolarimetry of the long period eclipsing AM Herculis binary V1309
We report simultaneous UBVRI photo-polarimetric observations of the long
period (7.98 h) AM Her binary V1309 Ori. The length and shape of the eclipse
ingress and egress varies from night to night. We suggest this is due to the
variation in the brightness of the accretion stream. By comparing the phases of
circular polarization zero-crossovers with previous observations, we confirm
that V1309 Ori is well synchronized, and find an upper limit of 0.002 percent
for the difference between the spin and orbital periods. We model the
polarimetry data using a model consisting of two cyclotron emission regions at
almost diametrically opposite locations, and centered at colatitude 35 (deg)
and 145 (deg) on the surface of the white dwarf. We also present archive X-ray
observations which show that the negatively polarised accretion region is X-ray
bright.Comment: 11 pages, 12 figures (2 colour), Fig1 and Fig 4 are in lower
resolution than in original paper, accepted for publication in Monthly
Notices of the Royal Astronomical Societ
Marked deterioration in the quality of life of patients with idiopathic pulmonary fibrosis during the last two years of life
BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic disease with a high symptom burden and poor survival that influences patients' health-related quality of life (HRQOL). We aimed to evaluate IPF patients' symptoms and HRQOL in a well-documented clinical cohort during their last two years of life.MethodsIn April 2015, we sent the Modified Medical Research Council Dyspnea Scale (MMRC), the modified Edmonton Symptom Assessment Scale (ESAS) and a self-rating HRQOL questionnaire (RAND-36) to 300 IPF patients, of which 247 (82%) responded. Thereafter, follow-up questionnaires were sent every six months for two years.ResultsNinety-two patients died by August 2017. Among these patients, HRQOL was found to be considerably low already two years before death. The most prominent declines in HRQOL occurred in physical function, vitality, emotional role and social functioning (pPeer reviewe
Rigidity of escaping dynamics for transcendental entire functions
We prove an analog of Boettcher's theorem for transcendental entire functions
in the Eremenko-Lyubich class B. More precisely, let f and g be entire
functions with bounded sets of singular values and suppose that f and g belong
to the same parameter space (i.e., are *quasiconformally equivalent* in the
sense of Eremenko and Lyubich). Then f and g are conjugate when restricted to
the set of points which remain in some sufficiently small neighborhood of
infinity under iteration. Furthermore, this conjugacy extends to a
quasiconformal self-map of the plane.
We also prove that this conjugacy is essentially unique. In particular, we
show that an Eremenko-Lyubich class function f has no invariant line fields on
its escaping set.
Finally, we show that any two hyperbolic Eremenko-Lyubich class functions f
and g which belong to the same parameter space are conjugate on their sets of
escaping points.Comment: 28 pages; 2 figures. Final version (October 2008). Various
modificiations were made, including the introduction of Proposition 3.6,
which was not formally stated previously, and the inclusion of a new figure.
No major changes otherwis
Conformal Mappings and Dispersionless Toda hierarchy
Let be the space consists of pairs , where is a
univalent function on the unit disc with , is a univalent function
on the exterior of the unit disc with and
. In this article, we define the time variables , on which are holomorphic with respect to the natural
complex structure on and can serve as local complex coordinates
for . We show that the evolutions of the pair with
respect to these time coordinates are governed by the dispersionless Toda
hierarchy flows. An explicit tau function is constructed for the dispersionless
Toda hierarchy. By restricting to the subspace consists
of pairs where , we obtain the integrable hierarchy
of conformal mappings considered by Wiegmann and Zabrodin \cite{WZ}. Since
every homeomorphism of the unit circle corresponds uniquely to
an element of under the conformal welding
, the space can be naturally
identified as a subspace of characterized by . We
show that we can naturally define complexified vector fields \pa_n, n\in \Z
on so that the evolutions of on
with respect to \pa_n satisfy the dispersionless Toda
hierarchy. Finally, we show that there is a similar integrable structure for
the Riemann mappings . Moreover, in the latter case, the time
variables are Fourier coefficients of and .Comment: 23 pages. This is to replace the previous preprint arXiv:0808.072
Measuring Black Hole Spin in OJ287
We model the binary black hole system OJ287 as a spinning primary and a
non-spinning secondary. It is assumed that the primary has an accretion disk
which is impacted by the secondary at specific times. These times are
identified as major outbursts in the light curve of OJ287. This identification
allows an exact solution of the orbit, with very tight error limits. Nine
outbursts from both the historical photographic records as well as from recent
photometric measurements have been used as fixed points of the solution: 1913,
1947, 1957, 1973, 1983, 1984, 1995, 2005 and 2007 outbursts. This allows the
determination of eight parameters of the orbit. Most interesting of these are
the primary mass of , the secondary mass , major axis precession rate per period, and the
eccentricity of the orbit 0.70. The dimensionless spin parameter is
(1 sigma). The last parameter will be more tightly
constrained in 2015 when the next outburst is due. The outburst should begin on
15 December 2015 if the spin value is in the middle of this range, on 3 January
2016 if the spin is 0.25, and on 26 November 2015 if the spin is 0.31. We have
also tested the possibility that the quadrupole term in the Post Newtonian
equations of motion does not exactly follow Einstein's theory: a parameter
is introduced as one of the 8 parameters. Its value is within 30% (1 sigma) of
the Einstein's value . This supports the of black
holes within the achievable precision. We have also measured the loss of
orbital energy due to gravitational waves. The loss rate is found to agree with
Einstein's value with the accuracy of 2% (1 sigma).Comment: 12 pages, 4 figures, IAU26
Tsuji functions with segments of Julia
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46297/1/209_2005_Article_BF01112579.pd
Assessing the utilization of the decision to implement a palliative goal for the treatment of cancer patients during the last year of life at Helsinki University Hospital : a historic cohort study
Background: To avoid aggressive treatments at the end-of-life and to provide palliative care (PC), physicians need to terminate futile anti-cancer treatments and define the palliative goal of the treatment in time. This single center study assesses the practices used to make the decision that leads to treatment with a palliative goal, i.e., the PC decision and its effect on anti-cancer treatments at the end of life. Material and methods: Patients with a cancer diagnosis treated in tertiary hospital during 1st January 2013 - 31st December 2014 and deceased by the end of 2014 were identified in the hospital database (N = 2737). Of these patients, 992 were randomly selected for this study. The PC decision was screened from patient records, i.e., termination of cancer-specific treatments and a focus on symptom-centered PC. Results: The PC decision was defined in 82% of the patients during the last year of life (49% >30 days and 33%Peer reviewe
The impact of the duration of the palliative care period on cancer patients with regard to the use of hospital services and the place of death : a retrospective cohort study
Background In order to avoid unnecessary use of hospital services at the end-of-life, palliative care should be initiated early enough in order to have sufficient time to initiate and carry out good quality advance care planning (ACP). This single center study assesses the impact of the PC decision and its timing on the use of hospital services at EOL and the place of death. Methods A randomly chosen cohort of 992 cancer patients treated in a tertiary hospital between Jan 2013 -Dec 2014, who were deceased by the end of 2014, were selected from the total number of 2737 identified from the hospital database. The PC decision (the decision to terminate life-prolonging anticancer treatments and focus on symptom centered palliative care) and use of PC unit services were studied in relation to emergency department (ED) visits, hospital inpatient days and place of death. Results A PC decision was defined for 82% of the patients and 37% visited a PC unit. The earlier the PC decision was made, the more often patients had an appointment at the PC unit (> 180 days prior to death 72% and <14 days 10%). The number of ED visits and inpatient days were highest for patients with no PC decision and lowest for patients with both a PC decision and an PC unit appointment (60 days before death ED visits 1.3 vs 0.8 and inpatient days 9.9 vs 2.9 respectively, p <0.01). Patients with no PC decision died more often in secondary/tertiary hospitals (28% vs. 19% with a PC decision, and 6% with a decision and an appointment to a PC unit). Conclusions The PC decision to initiate a palliative goal for the treatment had a distinct impact on the use of hospital services at the EOL. Contact with a PC unit further increased the likelihood of EOL care at primary care.Peer reviewe
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