697 research outputs found
Nova Sagittarii 1998 (V4633 Sgr) - a permanent superhump system or an asynchronous polar?
We report the results of observations of V4633 Sgr (Nova Sagittarii 1998)
during 1998-2000. Two photometric periodicities were present in the light curve
during the three years of observations: a stable one at P=3.014 h, which is
probably the orbital period of the underlying binary system, and a second one
of lower coherence, approximately 2.5 per cent longer than the former. The
latter periodicity may be a permanent superhump, or alternatively, the spin
period of the white dwarf in a nearly synchronous magnetic system. A third
period, at P=5.06 d, corresponding to the beat between the two periods was
probably present in 1999. Our results suggest that a process of mass transfer
took place in the binary system since no later than two and a half months after
the nova eruption. We derive an interstellar reddening of E(B-V)~0.21 from our
spectroscopic measurements and published photometric data, and estimate a
distance of d~9 kpc to this nova.Comment: 13 pages, latex, 7 figures, accepted for publication in MNRA
Non-Walker Self-Dual Neutral Einstein Four-Manifolds of Petrov Type III
The local structure of the manifolds named in the title is described.
Although curvature homogeneous, they are not, in general, locally homogeneous.
Not all of them are Ricci-flat, which answers an existence question about type
III Jordan-Osserman metrics, raised by Diaz-Ramos, Garcia-Rio and
Vazquez-Lorenzo (2006).Comment: 47 pages; a reference and a grant number were adde
The extended-track reconstruction for MiniBooNE
The Booster Neutrino Experiment (MiniBooNE) searches for muon neutrino to
electron neutrino oscillations using the ~1 GeV neutrino beam produced by the
FNAL Booster synchrotron. The array of photomultiplier tubes (PMTs) lining the
MiniBooNE detector records Cherenkov and scintillation photons from the charged
particles produced in neutrino interactions. We describe a maximum likelihood
fitting algorithm used to reconstruct the basic properties (position,
direction, energy) of these particles from the charges and times measured by
the PMTs. The likelihoods returned from fitting an event to different particle
hypotheses are used to categorize it as a signal electron neutrino event or as
one of the background muon neutrino processes, in particular charged current
quasi-elastic scattering and neutral current production. The
reconstruction and event selection techniques described here can be applied to
current and future neutrino experiments using similar Cherenkov-based
detection.Comment: 39 pages, 25 figures. Version 2 includes minor editorial change
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"Object Categorization: Reversals and Explanations of the Basic-Level Advantage" (Rogers & Patterson, 2007): A simplicity account
T. T. Rogers and K. Patterson (2007), in their article “Object Categorization: Reversals and Explanations of the Basic-Level Advantage” (Journal of Experimental Psychology: General, 136, 451–469), reported an impressive set of results demonstrating a reversal of the highly robust basic-level advantage both in patients with semantic dementia and in healthy individuals engaged in a speeded categorization task. To explain their results, as well as the usual basic-level advantage seen in healthy individuals, the authors employed a parallel distributed processing theory of conceptual knowledge. In this paper, we introduce an alternative way of explaining the results of Rogers and Patterson, which is premised on a more restricted set of assumptions born from standard categorization theory. Specifically, we provide evidence that their results can be accounted for based on the predictions of the simplicity model of unsupervised categorization
Application of the 2008 definitions for invasive fungal diseases to the trial comparing voriconazole versus amphotericin B for therapy of invasive aspergillosis: a collaborative study of the Mycoses Study Group (MSG 05) and the European Organization for Research and Treatment of Cancer Infectious Diseases Group.
BACKGROUND: Strict definition of invasive aspergillosis (IA) cases is required to allow precise conclusions about the efficacy of antifungal therapy. The Global Comparative Aspergillus Study (GCAS) compared voriconazole to amphotericin B (AmB) deoxycholate for the primary therapy of IA. Because predefined definitions used for this trial were substantially different from the consensus definitions proposed by the European Organization for Research and Treatment of Cancer/Mycoses Study Group in 2008, we recategorized the 379 episodes of the GCAS according to the later definitions.
METHODS: The objectives were to assess the impact of the current definitions on the classification of the episodes and to provide comparative efficacy for probable/proven and possible IA in patients treated with either voriconazole or AmB. In addition to original data, we integrated the results of baseline galactomannan serum levels obtained from 249 (65.7%) frozen samples. The original response assessment was accepted unchanged.
RESULTS: Recategorization allowed 59 proven, 178 probable, and 106 possible IA cases to be identified. A higher favorable 12-week response rate was obtained with voriconazole (54.7%) than with AmB (29.9%) (P < .0001). Survival was higher for voriconazole for mycologically documented (probable/proven) IA (70.2%) than with AmB (54.9%) (P = .010). Higher response rates were obtained in possible IA treated with voriconazole vs AmB with the same magnitude of difference (26.2%; 95% confidence interval [CI], 7.2%-45.3%) as in mycologically documented episodes (24.3%; 95% CI, 11.9%-36.7%), suggesting that possible cases are true IA.
CONCLUSIONS: Recategorization resulted in a better identification of the episodes and confirmed the higher efficacy of voriconazole over AmB deoxycholate in mycologically documented IA
Exploring pathways to optimise care in malignant bowel obstruction (EPOC): Protocol for a three-phase critical realist approach to theory-led intervention development for shared decision-making
Introduction Malignant bowel obstruction is a distressing complication of cancer, causing pain, nausea and vomiting, and often has a poor prognosis. Severe and rapidly developing symptoms, a lack of robust clinical guidelines and the need for multidisciplinary input make treatment decision-making challenging. Sharing decision-making with people with malignant bowel obstruction and their caregivers can be difficult, and inconsistent communication creates serious deficiencies in care by amplifying patients’ distress and uncertainty. Little attention has been paid to the implicit influences on this process–for example, the role of discipline-related norms and the beliefs of decision-makers. This study will explore how these processes work and develop interventions to improve shared decision-making. Methods and analysis Exploring Pathways to Optimise Care (EPOC) is a three-phase study set within a critical realist framework: (i) realist review, to develop explanatory theory describing collaborative decision-making in the management of malignant bowel obstruction; (ii) an in-depth interview study using modified grounded theory to explore the active ingredients of this collaboration in practice settings; and (iii) the presentation to stakeholders (practitioners, patients and caregivers) of integrated results from Phase I (theory developed from the literature) and Phase II (theory developed from current practice) as a basis for intervention mapping. We aim to produce recommendations to address the challenges, and to develop a set of tools to (i) aid interaction around shared decision-making and (ii) aid interprofessional interaction around the management of this condition
First Observation of Coherent Production in Neutrino Nucleus Interactions with 2 GeV
The MiniBooNE experiment at Fermilab has amassed the largest sample to date
of s produced in neutral current (NC) neutrino-nucleus interactions at
low energy. This paper reports a measurement of the momentum distribution of
s produced in mineral oil (CH) and the first observation of coherent
production below 2 GeV. In the forward direction, the yield of events
observed above the expectation for resonant production is attributed primarily
to coherent production off carbon, but may also include a small contribution
from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino
flux, the sum of the NC coherent and diffractive modes is found to be (19.5
1.1 (stat) 2.5 (sys))% of all exclusive NC production at
MiniBooNE. These measurements are of immediate utility because they quantify an
important background to MiniBooNE's search for
oscillations.Comment: Submitted to Phys. Lett.
An Outcome Evaluation of the Implementation of the Triple P – Positive Parenting Program in Hong Kong
The present study evaluated the effectiveness of the Positive Parenting Program (Triple P) with a sample of Chinese parents of children with early onset conduct related problems in Hong Kong. The participants consisted of 91 parents whose children attended maternal and child health centers and child assessment centers for service, and were between three to seven years old. Participants were randomly assigned to the intervention (TP) and a waitlist control group (WL. There was no significant difference in pre-intervention measures between the two groups. However, at post intervention, participants in the TP group reported significantly lower levels of child behavior problems, lower dysfunctional parenting styles, and higher parent sense of competence, compared to the WL group. Implications of these findings for the use of Triple P with families of Chinese descent are discussed
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
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