699 research outputs found
Constraining mass ratio and extinction in the FU Orionis binary system with infrared integral field spectroscopy
We report low resolution near infrared spectroscopic observations of the
eruptive star FU Orionis using the Integral Field Spectrograph Project 1640
installed at the Palomar Hale telescope. This work focuses on elucidating the
nature of the faint source, located 0.5" south of FU Ori, and identified in
2003 as FU Ori S. We first use our observations in conjunction with published
data to demonstrate that the two stars are indeed physically associated and
form a true binary pair. We then proceed to extract J and H band
spectro-photometry using the damped LOCI algorithm, a reduction method tailored
for high contrast science with IFS. This is the first communication reporting
the high accuracy of this technique, pioneered by the Project 1640 team, on a
faint astronomical source. We use our low resolution near infrared spectrum in
conjunction with 10.2 micron interferometric data to constrain the infrared
excess of FU Ori S. We then focus on estimating the bulk physical properties of
FU Ori S. Our models lead to estimates of an object heavily reddened, A_V
=8-12, with an effective temperature of ~ 4000-6500 K . Finally we put these
results in the context of the FU Ori N-S system and argue that our analysis
provides evidence that FU Ori S might be the more massive component of this
binary syste
Researching trust in the police and trust in justice: a UK perspective
This paper describes the immediate and more distant origins of a programme of comparative research that is examining cross-national variations in public trust in justice and in the police. The programme is built around a module of the fifth European Social Survey, and evolved from a study funded by the European Commission. The paper describes the conceptual framework within which we are operating – developed in large measure from theories of procedural justice. It reviews some of the methodological issues raised by the use of sample surveys to research issues of public trust in the police, public perceptions of institutional legitimacy and compliance with the law. Finally it gives a flavour of some of the early findings emerging from the programme
Ballistic Impact of Braided Composites with a Soft Projectile
Impact tests using a soft gelatin projectile were performed to identify failure modes that occur at high strain energy density during impact loading. Failure modes were identified for aluminum plates and for composites plates and half-rings made from triaxial carbon fiber braid having a 0/+/- 60deg architecture. For aluminum plates, a large hole formed as a result of crack propagation from the initiation site at the center of the plate. For composite plates, fiber tensile failure occurred in the back ply at the center of the plate. Cracks then propagated from this site along the +/-60deg fiber directions until triangular flaps opened to form a hole. For composite half-rings fabricated with 0deg fibers aligned circumferentially, fiber tensile failure also occurred in the back ply. Cracks first propagated from this site perpendicular the 0deg fibers. The cracks then turned to follow the +/-60deg fibers and 0deg fibers until rectangular flaps opened to form a hole. Damage in the composites was localized near the impact site, while cracks in the aluminum extended to the boundaries
G313.3+00.3: A New Planetary Nebula discovered by the Australia Telescope Compact Array and the Spitzer Space Telescope
We present a new planetary nebula, first identified in images from the
Australia Telescope Compact Array, although not recognized at that time. Recent
observations with the Spitzer Space Telescope during the GLIMPSE Legacy program
have rediscovered the object. The high-resolution radio and infrared images
enable the identification of the central star or its wind, the recognition of
the radio emission as thermal, and the probable presence of polycylic aromatic
hydrocarbons in and around the source. These lead to the conclusion that
G313.3+00.3 is a planetary nebula. This object is of particular interest
because it was discovered solely through radio and mid-infrared imaging,
without any optical (or near-infrared) confirmation, and acts as a proof of
concept for the discovery of many more highly extinguished planetary nebulae.
G313.3+00.3 is well-resolved by both the instruments with which it was
identified, and suffers extreme reddening due to its location in the
Scutum-Crux spiral arm.Comment: 18 pages, LaTeX (aastex), incl. 8 PostScript (eps) figures and 1
table. Accepted by ApJ (Part 1
Challenges of Profile Likelihood Evaluation in Multi-Dimensional SUSY Scans
Statistical inference of the fundamental parameters of supersymmetric
theories is a challenging and active endeavor. Several sophisticated algorithms
have been employed to this end. While Markov-Chain Monte Carlo (MCMC) and
nested sampling techniques are geared towards Bayesian inference, they have
also been used to estimate frequentist confidence intervals based on the
profile likelihood ratio. We investigate the performance and appropriate
configuration of MultiNest, a nested sampling based algorithm, when used for
profile likelihood-based analyses both on toy models and on the parameter space
of the Constrained MSSM. We find that while the standard configuration is
appropriate for an accurate reconstruction of the Bayesian posterior, the
profile likelihood is poorly approximated. We identify a more appropriate
MultiNest configuration for profile likelihood analyses, which gives an
excellent exploration of the profile likelihood (albeit at a larger
computational cost), including the identification of the global maximum
likelihood value. We conclude that with the appropriate configuration MultiNest
is a suitable tool for profile likelihood studies, indicating previous claims
to the contrary are not well founded.Comment: 21 pages, 9 figures, 1 table; minor changes following referee report.
Matches version accepted by JHE
Self-reported dominance in women: Associations with hormonal contraceptive use, relationship status, and testosterone
How to achieve dominance in a group is a recurrent challenge for individuals of many species, including humans. Previous research indicates that both relationship status and contraceptive use appear to moderate women’s testosterone levels. If testosterone contributes to dominance, this raises the possibility for group differences in dominance between single and partnered women, and between users and non-users of hormonal contraception. Here, we examine associations between relationship status and use/non-use of hormonal contraception and women’s self-reported social dominance. In a sample of 84 women, we replicate previous research documenting a significant positive correlation between women’s saliva testosterone levels and their self-reported dominance. Consistent with other literature, we also find that women using hormonal contraception have significantly lower testosterone than those who are regularly cycling and that partnered women have significantly lower testosterone than single women. Although we do not find a main effect of either relationship status or hormonal contraceptive use status on women’s reported levels of dominance, the interaction between these variables predicted reported dominance scores. This interaction remained significant when participant age and testosterone values were added to the model as covariates. We discuss these results in the context of the existing literature on testosterone and women’s dominance behaviour and with respect to the evolutionary benefits of social dominance in women
The BRICS (Bronchiectasis Radiologically Indexed CT Score)- a multi-center study score for use in idiopathic and post infective bronchiectasis
OBJECTIVES: The goal of this study was to develop a simplified radiological score that could assess clinical disease severity in bronchiectasis. METHODS: The Bronchiectasis Radiologically Indexed CT Score (BRICS) was devised based on a multivariable analysis of the Bhalla score and its ability in predicting clinical parameters of severity. The score was then externally validated in six centers in 302 patients. RESULTS: A total of 184 high-resolution CT scans were scored for the validation cohort. In a multiple logistic regression model, disease severity markers significantly associated with the Bhalla score were percent predicted FEV1, sputum purulence, and exacerbations requiring hospital admission. Components of the Bhalla score that were significantly associated with the disease severity markers were bronchial dilatation and number of bronchopulmonary segments with emphysema. The BRICS was developed with these two parameters. The receiver operating-characteristic curve values for BRICS in the derivation cohort were 0.79 for percent predicted FEV1, 0.71 for sputum purulence, and 0.75 for hospital admissions per year; these values were 0.81, 0.70, and 0.70, respectively, in the validation cohort. Sputum free neutrophil elastase activity was significantly elevated in the group with emphysema on CT imaging. CONCLUSIONS: A simplified CT scoring system can be used as an adjunct to clinical parameters to predict disease severity in patients with idiopathic and postinfective bronchiectasis
What is the evidence for the management of patients along the pathway from the emergency department to acute admission to reduce unplanned attendance and admission? An evidence synthesis
Background
Globally, the rate of emergency hospital admissions is increasing. However, little evidence exists to inform the development of interventions to reduce unplanned Emergency Department (ED) attendances and hospital admissions. The objective of this evidence synthesis was to review the evidence for interventions, conducted during the patient’s journey through the ED or acute care setting, to manage people with an exacerbation of a medical condition to reduce unplanned emergency hospital attendance and admissions.
Methods
A rapid evidence synthesis, using a systematic literature search, was undertaken in the electronic data bases of MEDLINE, EMBASE, CINAHL, the Cochrane Library and Web of Science, for the years 2000–2014. Evidence included in this review was restricted to Randomised Controlled Trials (RCTs) and observational studies (with a control arm) reported in peer-reviewed journals. Studies evaluating interventions for patients with an acute exacerbation of a medical condition in the ED or acute care setting which reported at least one outcome related to ED attendance or unplanned admission were included.
Results
Thirty papers met our inclusion criteria: 19 intervention studies (14 RCTs) and 11 controlled observational studies. Sixteen studies were set in the ED and 14 were conducted in an acute setting. Two studies (one RCT), set in the ED were effective in reducing ED attendance and hospital admission. Both of these interventions were initiated in the ED and included a post-discharge community component. Paradoxically 3 ED initiated interventions showed an increase in ED re-attendance. Six studies (1 RCT) set in acute care settings were effective in reducing: hospital admission, ED re-attendance or re-admission (two in an observation ward, one in an ED assessment unit and three in which the intervention was conducted within 72 h of admission).
Conclusions
There is no clear evidence that specific interventions along the patient journey from ED arrival to 72 h after admission benefit ED re-attendance or readmission. Interventions targeted at high-risk patients, particularly the elderly, may reduce ED utilization and warrant future research. Some interventions showing effectiveness in reducing unplanned ED attendances and admissions are delivered by appropriately trained personnel in an environment that allows sufficient time to assess and manage patients
Fear of the human “super predator” far exceeds the fear of large carnivores in a model mesocarnivore
The fear (perceived predation risk) large carnivores inspire in mesocarnivores can affect ecosystem structure and function, and loss of the “landscape of fear” large carnivores create adds to concerns regarding the worldwide loss of large carnivores. Fear of humans has been proposed to act as a substitute but new research identifies humans as a “super predator” globally far more lethal to mesocarnivores, and thus presumably far more frightening. Although much of the world now consists of human-dominated landscapes there remains relatively little research regarding how behavioral responses to humans affecttrophic networks, to the extent that no study has yet experimentally tested the relative fearfulness mesocarnivores demonstrate in reaction to humans versus nonhuman predators. Badgers (Meles meles) in Britain are a model mesocarnivore insofar as they no longer need fear native large carnivores (bears, Ursus arctos; wolves, Canis lupus) and now perhaps fear humans more. We tested the fearfulness badgers demonstrated to audio playbacks of extant (dog) andextinct (bear and wolf) large carnivores, and humans, by assaying the suppression of foragingbehavior. Hearing humans affected all of: latency to feed, vigilance, foraging time, number of feeding visits, and number of badgers feeding. Hearing dogs and bears had far lesser effects on latency to feed, and hearing wolves had no effects. Our results indicate fear of humans evidently cannot substitute for the fear large carnivores inspire in mesocarnivores because humansare perceived as far more frightening, which we discuss in light of the recovery of large carnivores in human-dominated landscapes
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