1,299 research outputs found
Will Gravitational Wave Sirens Determine the Hubble Constant?
Lack of knowledge about the background expansion history of the Universe from
independent observations makes it problematic to obtain a precise and accurate
estimation of the Hubble constant from gravitational wave standard
sirens, even with electromagnetic counterpart redshifts. Simply fitting
simultaneously for the matter density in a flat \lcdm\ model can reduce the
precision on from 1\% to 5\%, while not knowing the actual background
expansion model of the universe (e.g.\ form of dark energy) can introduce
substantial bias in estimation of the Hubble constant. When the statistical
precision is at the level of 1\% uncertainty on , biases in non-\lcdm\
cosmologies that are consistent with current data could reach the 3
level. To avoid model-dependent biases, statistical techniques that are
appropriately agnostic about model assumptions need to be employed.Comment: 7 pages, 7 figure
Cluster Model for Near-barrier Fusion Induced by Weakly Bound and Halo Nuclei
The influence on the fusion process of coupling transfer/breakup channels is
investigated for the medium weight Li+Co systems in the vicinity
of the Coulomb barrier. Coupling effects are discussed within a comparison of
predictions of the Continuum Discretized Coupled-Channels model. Applications
to He+Co induced by the borromean halo nucleus He are also
proposed.Comment: 5 pages, 3 figures, FINUSTAR2 Conference, Aghios Nikolaus, Crete,
Greece. 10-14 September 200
Development of Prognosis in Palliative care Study (PiPS) predictor models to improve prognostication in advanced cancer: prospective cohort study
OBJECTIVE: To develop a novel prognostic indicator for use in patients with advanced cancer that is significantly better than clinicians' estimates of survival.
DESIGN: Prospective multicentre observational cohort study. SETTING: 18 palliative care services in the UK (including hospices, hospital support teams, and community teams). PARTICIPANTS: 1018 patients with locally advanced or metastatic cancer, no longer being treated for cancer, and recently referred to palliative care services.
MAIN OUTCOME MEASURES: Performance of a composite model to predict whether patients were likely to survive for "days" (0-13 days), "weeks" (14-55 days), or "months+" (>55 days), compared with actual survival and clinicians' predictions.
RESULTS: On multivariate analysis, 11 core variables (pulse rate, general health status, mental test score, performance status, presence of anorexia, presence of any site of metastatic disease, presence of liver metastases, C reactive protein, white blood count, platelet count, and urea) independently predicted both two week and two month survival. Four variables had prognostic significance only for two week survival (dyspnoea, dysphagia, bone metastases, and alanine transaminase), and eight variables had prognostic significance only for two month survival (primary breast cancer, male genital cancer, tiredness, loss of weight, lymphocyte count, neutrophil count, alkaline phosphatase, and albumin). Separate prognostic models were created for patients without (PiPS-A) or with (PiPS-B) blood results. The area under the curve for all models varied between 0.79 and 0.86. Absolute agreement between actual survival and PiPS predictions was 57.3% (after correction for over-optimism). The median survival across the PiPS-A categories was 5, 33, and 92 days and survival across PiPS-B categories was 7, 32, and 100.5 days. All models performed as well as, or better than, clinicians' estimates of survival.
CONCLUSIONS: In patients with advanced cancer no longer being treated, a combination of clinical and laboratory variables can reliably predict two week and two month survival
Cyclic changes in cortisol across the estrous cycle in parous and nulliparous Asian elephants
In the context of reproduction, glucocorticoids (GCs) are generally considered to have negative effects. However, in well-studied model species, GCs fluctuate predictability across the estrous cycles, and short-term increases promote healthy ovarian function. Reproductive challenges have plagued captive elephant populations, which are not currently self-sustaining. Efforts to understand reproductive dysfunction in elephants have focused on the suppressive effects of cortisol, but the potential permissive or stimulatory effects of cortisol are unknown. In this study, we provide a detailed examination of cortisol patterns across the estrous cycle in Asian elephants (Elephas maximus). Time series analysis was used to analyze cortisol and progesterone data for a total of 73 cycles from eight females. We also compared cortisol profiles between females that successfully conceived and females that failed to conceive despite repeated mating attempts. Our results revealed that cortisol fluctuates predictably across the estrous cycle, with a peak during the second half of the follicular phase followed by low levels throughout the luteal phase. Furthermore, this pattern was significantly altered in nulliparous females; cortisol concentrations did not decline during the luteal phase to the same extent as in parous females. This study highlights the complexity of cortisol signaling and suggests future directions for understanding the role of cortisol in reproductive dysfunction
Evidence for transfer followed by breakup in 7Li + 65Cu
The observation of a large cross-section for the alpha + d channel compared
to breakup into the alpha + t channel from an exclusive measurement for the
7Li+65Cu system at 25 MeV is presented. A detailed analysis of the angular
distribution using coupled channels Born approximation calculations has
provided clear evidence that the observed alpha + d events arise from a two
step process, i.e. direct transfer to the 2.186 MeV (3+) resonance in the alpha
+ d continuum of 6Li followed by breakup, and are not due to final state
interaction effects.Comment: 12 pages, 3 figures, To be published in Phys. Letts.
Complete genome assemblies of three highly prevalent, toxigenic clostridioides difficile strains causing health care-associated infections in Australia
Clostridioides difficile infection (CDI) is the leading cause of life-threatening health care-related gastrointestinal illness worldwide. Phylogenetically appropriate closed reference genomes are essential for studies of C. difficile transmission and evolution. Here, we provide high-quality complete hybrid genome assemblies for the three most prevalent C. difficile strains causing CDI in Australia
Determining Model-independent and Consistency Tests
We determine the Hubble constant precisely ( uncertainty) in a
manner independent of cosmological model through Gaussian process regression,
using strong lensing and supernova data. Strong gravitational lensing of a
variable source can provide a time-delay distance and angular
diameter distance to the lens . These absolute distances can anchor
Type Ia supernovae, which give an excellent constraint on the shape of the
distance-redshift relation. Updating our previous results to use the H0LiCOW
program's milestone dataset consisting of six lenses, four of which have both
and measurements, we obtain
for a flat universe and
for a non-flat universe. We carry out
several consistency checks on the data and find no statistically significant
tensions, though a noticeable redshift dependence persists in a particular
systematic manner that we investigate. Speculating on the possibility that this
trend of derived Hubble constant with lens distance is physical, we show how
this can arise through modified gravity light propagation, which would also
impact the weak lensing tension.Comment: 9 pages, 6 figures, 3 tables, title rephrase
- …