38 research outputs found
3D Gravity in a Box
The quantization of pure 3D gravity with Dirichlet boundary conditions on a
finite boundary is of interest both as a model of quantum gravity in which one
can compute quantities which are "more local" than S-matrices or asymptotic
boundary correlators, and for its proposed holographic duality to -deformed CFTs. In this work we apply covariant phase space
methods to deduce the Poisson bracket algebra of boundary observables. The
result is a one-parameter nonlinear deformation of the usual Virasoro algebra
of asymptotically AdS gravity. This algebra should be obeyed by the stress
tensor in any -deformed holographic CFT. We next initiate
quantization of this system within the general framework of coadjoint orbits,
obtaining - in perturbation theory - a deformed version of the
Alekseev-Shatashvili symplectic form and its associated geometric action. The
resulting energy spectrum is consistent with the expected spectrum of
-deformed theories, although we only carry out the explicit
comparison to in the expansion.Comment: 59 pages, corrected typos and minus signs. This is the published
versio
S-Matrix Path Integral Approach to Symmetries and Soft Theorems
We explore a formulation of the S-matrix in terms of the path integral with
specified asymptotic data, as originally proposed by Arefeva, Faddeev, and
Slavnov. In the tree approximation the S-matrix is equal to the exponential of
the classical action evaluated on-shell. This formulation is well-suited to
questions involving asymptotic symmetries, as it avoids reference to
non-gauge/diffeomorphism invariant bulk correlators or sources at intermediate
stages. We show that the soft photon theorem, originally derived by Weinberg
and more recently connected to asymptotic symmetries by Strominger and
collaborators, follows rather simply from invariance of the action under large
gauge transformations applied to the asymptotic data. We also show that this
formalism allows for efficient computation of the S-matrix in curved spacetime,
including particle production due to a time dependent metric.Comment: 38 page
A Nationally Representative Survey Assessing Restorative Sleep in US Adults
Restorative sleep is a commonly used term but a poorly defined construct. Few studies have assessed restorative sleep in nationally representative samples. We convened a panel of 7 expert physicians and researchers to evaluate and enhance available measures of restorative sleep. We then developed the revised Restorative Sleep Questionnaire (REST-Q), which comprises 9 items assessing feelings resulting from the prior sleep episode, each with 5-point Likert response scales. Finally, we assessed the prevalence of high, somewhat, and low REST-Q scores in a nationally representative sample of US adults (n= 1,055) and examined the relationship of REST-Q scores with other sleep and demographic characteristics. Pairwise correlations were performed between the REST-Q scores and other self-reported sleep measures. Weighted logistic regression analyses were conducted to compare scores on the REST-Q with demographic variables. The prevalence of higher REST-Q scores (4 or 5 on the Likert scale) was 28.1% in the nationally representative sample. REST-Q scores positively correlated with sleep quality (r=0.61) and sleep duration (r=0.32), and negatively correlated with both difficulty falling asleep (r=-0.40) and falling back asleep after waking (r=-0.41). Higher restorative sleep scores (indicating more feelings of restoration upon waking) were more common among those who were: ≥60 years of age (OR=4.20, 95%CI: 1.92-9.17); widowed (OR=2.35, 95%CI:1.01-5.42), and retired (OR=2.02, 95%CI:1.30-3.14). Higher restorative sleep scores were less frequent among those who were not working (OR=0.36, 95%CI: 0.10-1.00) and living in a household with two or more persons (OR=0.51,95%CI:0.29-0.87). Our findings suggest that the REST-Q may be useful for assessing restorative sleep
Whole breast and regional nodal irradiation in prone versus supine position in left sided breast cancer
Background: Prone whole breast irradiation (WBI) leads to reduced heart and lung doses in breast cancer patients receiving adjuvant radiotherapy. In this feasibility trial, we investigated the prone position for whole breast + lymph node irradiation (WB + LNI).
Methods: A new support device was developed for optimal target coverage, on which patients are positioned in a position resembling a phase from the crawl swimming technique (prone crawl position). Five left sided breast cancer patients were included and simulated in supine and prone position. For each patient, a treatment plan was made in prone and supine position for WB + LNI to the whole axilla and the unoperated part of the axilla. Patients served as their own controls for comparing dosimetry of target volumes and organs at risk (OAR) in prone versus in supine position.
Results: Target volume coverage differed only slightly between prone and supine position. Doses were significantly reduced (P < 0.05) in prone position for ipsilateral lung (Dmean, D2, V5, V10, V20, V30), contralateral lung (Dmean, D2), contralateral breast (Dmean, D2 and for total axillary WB + LNI also V5), thyroid (Dmean, D2, V5, V10, V20, V30), oesophagus (Dmean and for partial axillary WB + LNI also D2 and V5), skin (D2 and for partial axillary WB + LNI V105 and V107). There were no significant differences for heart and humeral head doses.
Conclusions: Prone crawl position in WB + LNI allows for good breast and nodal target coverage with better sparing of ipsilateral lung, thyroid, contralateral breast, contralateral lung and oesophagus when compared to supine position. There is no difference in heart and humeral head doses
REQUITE: A prospective multicentre cohort study of patients undergoing radiotherapy for breast, lung or prostate cancer
Purpose: REQUITE aimed to establish a resource for multi-national validation of models and biomarkers that predict risk of late toxicity following radiotherapy. The purpose of this article is to provide summary descriptive data.
Methods: An international, prospective cohort study recruited cancer patients in 26 hospitals in eight countries between April 2014 and March 2017. Target recruitment was 5300 patients. Eligible patients had breast, prostate or lung cancer and planned potentially curable radiotherapy. Radiotherapy was prescribed according to local regimens, but centres used standardised data collection forms. Pre-treatment blood samples were collected. Patients were followed for a minimum of 12 (lung) or 24 (breast/prostate) months and summary descriptive statistics were generated.
Results: The study recruited 2069 breast (99% of target), 1808 prostate (86%) and 561 lung (51%) cancer patients. The centralised, accessible database includes: physician-(47,025 forms) and patient-(54,901) reported outcomes; 11,563 breast photos; 17,107 DICOMs and 12,684 DVHs. Imputed genotype data are available for 4223 patients with European ancestry (1948 breast, 1728 prostate, 547 lung). Radiation-induced lymphocyte apoptosis (RILA) assay data are available for 1319 patients. DNA (n = 4409) and PAXgene tubes (n = 3039) are stored in the centralised biobank. Example prevalences of 2-year (1-year for lung) grade >= 2 CTCAE toxicities are 13% atrophy (breast), 3% rectal bleeding (prostate) and 27% dyspnoea (lung).
Conclusion: The comprehensive centralised database and linked biobank is a valuable resource for the radiotherapy community for validating predictive models and biomarkers.
Patient summary: Up to half of cancer patients undergo radiation therapy and irradiation of surrounding healthy tissue is unavoidable. Damage to healthy tissue can affect short-and long-term quality-of-life. Not all patients are equally sensitive to radiation "damage" but it is not possible at the moment to identify those who are. REQUITE was established with the aim of trying to understand more about how we could predict radiation sensitivity. The purpose of this paper is to provide an overview and summary of the data and material available.
In the REQUITE study 4400 breast, prostate and lung cancer patients filled out questionnaires and donated blood. A large amount of data was collected in the same way. With all these data and samples a database and biobank were created that showed it is possible to collect this kind of information in a standardised way across countries.
In the future, our database and linked biobank will be a resource for research and validation of clinical predictors and models of radiation sensitivity. REQUITE will also enable a better understanding of how many people suffer with radiotherapy toxicity
The Inconsistency Between Section 301 and TRIPS: Counterproductive With Respect to the Future of International Protection of Intellectual Property Rights?
This comment examines the inconsistency between continued international efforts to ensure uniform protection of intellectual property rights, most recently via the Trade-Related Aspects of Intellectual Property Rights Agreement (TRIPS), on the one hand; and the use of unilateral measures by the United States, specifically Section 301 of the Trade Act, to ensure greater protection for United States\u27 intellectual property rights, on the other. This comment first discusses the historical development of international protection of intellectual property rights, specifically focusing on the Paris Convention for the Protection of Industrial Property, the Berne Convention for the Protection of Literary and Artistic Property, the World Intellectual Property Organization, and TRIPS. It then outlines the development of Section 301, argues that the effects of its current use are inconsistent with WTO obligations, and shows that despite the inconsistency and fierce opposition from trading partners the United States continues both to use and to threaten to use Section 301 measures against countries that are deemed to provide inadequate protection for U.S. intellectual property rights. Via the specific example of gray market goods this comment demonstrates that countries would rather abandon their policies and agree to unilaterally negotiate with the United States - even when their current policies might very well be in perfect compliance with TRIPS - than risk being black-listed by the United States via Section 301 measures. This comment concludes that the measures employed by the United States are detrimental to the long term goals of international protection of intellectual property and, unless altered, will continue to create animosity from those trading partners who do not engage in such practices, as well as from those that are forced into such negotiations. Hence, as the most powerful member of the WTO, in the best interest of the world trading community as whole, the United States would be wise to reconsider its use of Section 301