961 research outputs found
The Retail City in Greater Birmingham – The changing face of urban retail districts as a result of retail-led regeneration and containment policy
The paper critically reviews retail-led regeneration and retail containment polices and their effects on the urban retail in the UK by analysing the effect that retail-led mega-schemes regeneration projects have on the economic growth of inner cities. There is significant controversy whether mega-schemes in retail-led regeneration initiatives contribute to the growth of local economies or whether it leads to the pitch shifting and marginalisation of local retail. The research focuses on two neighbouring strategies in Birmingham and Solihull to determine differences in the application of retail-led regeneration in inner city and peripheral locations. Birmingham’s Bullring centre and Solihull’s Touchstone centre was researched using quantitative data on the growth of the retail sector in Birmingham and supplemented using interviews with key actors. The paper critically analyses whether retail-led mega-schemes have a net positive effect on the economic revitalisation of the deteriorating inner cities. The results of the research indicate that the retail-led regeneration initiative brought about a dual economy with a global inner core of national retail and the outer core of marginalised local retail. The economic motive of implementing retail-led regeneration is doubted, as the research delivers mixed results. However the research indicates that the strategic benefits of restructuring and marketing the city have become equally if of not more important in retail-led regeneration initiatives than the actual economic benefits for the local economic community.
On the efficient Monte Carlo implementation of path integrals
We demonstrate that the Levy-Ciesielski implementation of Lie-Trotter
products enjoys several properties that make it extremely suitable for
path-integral Monte Carlo simulations: fast computation of paths, fast Monte
Carlo sampling, and the ability to use different numbers of time slices for the
different degrees of freedom, commensurate with the quantum effects. It is
demonstrated that a Monte Carlo simulation for which particles or small groups
of variables are updated in a sequential fashion has a statistical efficiency
that is always comparable to or better than that of an all-particle or
all-variable update sampler. The sequential sampler results in significant
computational savings if updating a variable costs only a fraction of the cost
for updating all variables simultaneously or if the variables are independent.
In the Levy-Ciesielski representation, the path variables are grouped in a
small number of layers, with the variables from the same layer being
statistically independent. The superior performance of the fast sampling
algorithm is shown to be a consequence of these observations. Both mathematical
arguments and numerical simulations are employed in order to quantify the
computational advantages of the sequential sampler, the Levy-Ciesielski
implementation of path integrals, and the fast sampling algorithm.Comment: 14 pages, 3 figures; submitted to Phys. Rev.
What\u27s missing in missing data? Omissions in survey responses among parents of children with advanced cancer
Background: Missing data is a common phenomenon with survey-based research; patterns of missing data may elucidate why participants decline to answer certain questions. Objective: To describe patterns of missing data in the Pediatric Quality of Life and Evaluation of Symptoms Technology (PediQUEST) study, and highlight challenges in asking sensitive research questions. Design: Cross-sectional, survey-based study embedded within a randomized controlled trial. Setting: Three large children\u27s hospitals: Dana-Farber/Boston Children\u27s Cancer and Blood Disorders Center (DF/BCCDC); Children\u27s Hospital of Philadelphia (CHOP); and Seattle Children\u27s Hospital (SCH). Measurements: At the time of their child\u27s enrollment, parents completed the Survey about Caring for Children with Cancer (SCCC), including demographics, perceptions of prognosis, treatment goals, quality of life, and psychological distress. Results: Eighty-six of 104 parents completed surveys (83% response). The proportion of missing data varied by question type. While 14 parents (16%) left demographic fields blank, over half (n=48; 56%) declined to answer at least one question about their child\u27s prognosis, especially life expectancy. The presence of missing data was unrelated to the child\u27s diagnosis, time from progression, time to death, or parent distress (p>0.3 for each). Written explanations in survey margins suggested that addressing a child\u27s life expectancy is particularly challenging for parents. Conclusions and Relevance: Parents of children with cancer commonly refrain from answering questions about their child\u27s prognosis, however, they may be more likely to address general cure likelihood than explicit life expectancy. Understanding acceptability of sensitive questions in survey-based research will foster higher quality palliative care research. © Copyright 2014, Mary Ann Liebert, Inc. 2014
Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer
Adjuvant therapy; Breast cancer; OlaparibTerapia adyuvante; Cáncer de mama; OlaparibTerà pia adjuvant; Cà ncer de mama; OlaparibBackground
The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.
Patients and methods
One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.
Results
With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI −0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.
Conclusion
With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.Funding for this work, which was conducted as a collaborative partnership among the Breast International Group, NRG Oncology, Frontier Science, AstraZeneca, and Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, U.S.A. (MSD), was provided by the National Institutes of Health (grant numbers: U10CA 180868, UG1CA 189867, and U10CA 180822) and by AstraZeneca as part of an alliance between AstraZeneca and MSD. Provision of olaparib and placebo was from AstraZeneca
Renormalisation of heavy-light light ray operators
We calculate the renormalisation of different light ray operators with one
light degree of freedom and a static heavy quark. Both - and
-kernels are considered. A comparison with the light-light case suggests
that the mixing with three-particle operators is solely governed by the light
degrees of freedom. Additionally we show that conformal symmetry is already
broken at the level of the one loop counterterms due to the additional
UV-renormalisation of a cusp in the two contributing Wilson-lines. This general
feature can be used to fix the -renormalisation kernels up to a
constant. Some examples for applications of our results are given.Comment: 23 pages, 5 figures; v2: changed some wording, added a few references
and one appendix concerning some subtleties related to gauge fixing and ghost
terms; v3: clarified calculation in section 3.2., added an explicit
calculation in section 5.2, corrected a few typos and one figure, added a few
comments, results unchanged, except for typesetting matches version to appear
in JHE
Epirubicin With Cyclophosphamide Followed by Docetaxel With Trastuzumab and Bevacizumab as Neoadjuvant Therapy for HER2-Positive Locally Advanced Breast Cancer or as Adjuvant Therapy for HER2-Positive Pathologic Stage III Breast Cancer: A Phase II Trial of the NSABP Foundation Research Group, FB-5
Background The purpose of this study was to determine the cardiac safety and clinical activity of trastuzumab and bevacizumab with docetaxel after epirubicin with cyclophosphamide (EC) in patients with HER2-positive locally advanced breast cancer (LABC) or pathologic stage 3 breast cancer (PS3BC). Patients and Methods Patients received every 3 week treatment with 4 cycles of EC (90/600 mg/m2) followed by 4 cycles of docetaxel (100 mg/m2). Targeted therapy with standard-dose trastuzumab with bevacizumab 15 mg/kg was given for a total of 1 year. Coprimary end points were (1) rate of cardiac events (CEs) in all patients defined as clinical congestive heart failure with a significant decrease in left ventricular ejection fraction or cardiac deaths; and (2) pathologic complete response (pCR) in breast and nodes in the neoadjuvant cohort. An independent cardiac review panel determined whether criteria for a CE were met. Results A total of 105 patients were accrued, 76 with LABC treated with neoadjuvant therapy and 29 with PS3BC treated with adjuvant therapy. Median follow-up was 59.2 months. Among 99 evaluable patients for cardiac safety, 4 (4%; 95% confidence interval [CI], 1.1%-10.0%) met CE criteria. The pCR percentage in LABC patients was 46% (95% CI, 34%-59%). Five-year recurrence-free survival (RFS) and overall survival (OS) for all patients was 79.9% and 90.8%, respectively. Conclusion The regimen met predefined criteria for activity of interest with an acceptable rate of CEs. Although the pCR percentage was comparable with chemotherapy regimens with trastuzumab alone the high RFS and OS are of interest in these high-risk populations
A Survey of Open Clusters in the u'g'r'i'z' Filter System: I. Results for NGC2548 (M48)
We present initial results of a photometric survey of open star clusters,
primarily in the southern hemisphere, taken in the u'g'r'i'z' filter system.
While our entire observed sample covers more than 100 clusters, here we present
data for NGC2548 (M48) which is a cluster characterized in the UBV and DDO
photometric systems. We compare our results to the published values from other
observers and to the Padova theoretical isochrones and metallicity curves.
These observations demonstrate that the u'g'r'i'z' filters can play an
important role in determining the metallicity of stars and clusters. We begin
this series of papers with a study of NGC2548 because we have obtained data of
this cluster not only with our main program telescope, the CTIO Curtis-Schmidt,
but also with the US Naval Observatory (USNO) 1.0m telescope (the telescope
used to define the u'g'r'i'z' system), and the Sloan Digital Sky Survey (SDSS)
0.5m Photometric Telescope (the photometric monitoring telescope used to
calibrate the SDSS 2.5m telescope imaging data). We have used the data from
this study to validate our ability to transform measurements obtained on other
telescopes to the standard USNO 1.0m u'g'r'i'z' system. This validation is
particularly important for very red stars, for which the original u'g'r'i'z'
standard star network is poorly constrained.Comment: 32 pages, 8 figures. Complete, machine-readable versions of Tables
4-6 available at http://home.fnal.gov/~dtucker/OpenClusters/NGC2548/ .
Accepted for publication in the Astronomical Journa
Quantifying vertical mixing in estuaries
© 2008 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Environmental Fluid Mechanics 8 (2008): 495-509, doi:10.1007/s10652-008-9107-2.Estuarine turbulence is notable in that both the dissipation rate and the buoyancy frequency extend to much higher values than in other natural environments. The high dissipation rates lead to a distinct inertial subrange in the velocity and scalar spectra, which can be exploited for quantifying the turbulence quantities. However, high buoyancy frequencies lead to small Ozmidov scales, which require high sampling rates and small spatial aperture to resolve the turbulent fluxes. A set of observations in a highly stratified estuary demonstrate the effectiveness of a vessel-mounted turbulence array for resolving turbulent processes, and for relating the turbulence to the forcing by the Reynolds-averaged flow. The observations focus on the ebb, when most of the buoyancy flux occurs. Three stages of mixing are observed: (1) intermittent and localized but intense shear instability during the early ebb; (2) continuous and relatively homogeneous shear-induced mixing during the mid-ebb, and weakly stratified, boundary-layer mixing during the late ebb. The mixing efficiency as quantified by the flux Richardson number Rf was frequently observed to be higher than the canonical value of 0.15 from Osborn (J Phys Oceanogr 10:83–89, 1980). The high efficiency may be linked to the temporal–spatial evolution of shear instabilities.The funding for this research was obtained from ONR Grant N00014-06-1-0292
and NSF Grant OCE-0729547
Sleep-effects on implicit and explicit memory in repeated visual search
In repeated visual search tasks, facilitation of reaction times (RTs) due to repetition of the spatial arrangement of items occurs independently of RT facilitation due to improvements in general task performance. Whereas the latter represents typical procedural learning, the former is a kind of implicit memory that depends on the medial temporal lobe (MTL) memory system and is impaired in patients with amnesia. A third type of memory that develops during visual search is the observers’ explicit knowledge of repeated displays. Here, we used a visual search task to investigate whether procedural memory, implicit contextual cueing, and explicit knowledge of repeated configurations, which all arise independently from the same set of stimuli, are influenced by sleep. Observers participated in two experimental sessions, separated by either a nap or a controlled rest period. In each of the two sessions, they performed a visual search task in combination with an explicit recognition task. We found that (1) across sessions, MTL-independent procedural learning was more pronounced for the nap than rest group. This confirms earlier findings, albeit from different motor and perceptual tasks, showing that procedural memory can benefit from sleep. (2) Likewise, the sleep group compared with the rest group showed enhanced context-dependent configural learning in the second session. This is a novel finding, indicating that the MTL-dependent, implicit memory underlying contextual cueing is also sleep-dependent. (3) By contrast, sleep and wake groups displayed equivalent improvements in explicit recognition memory in the second session. Overall, the current study shows that sleep affects MTL-dependent as well as MTL-independent memory, but it affects different, albeit simultaneously acquired, forms of MTL-dependent memory differentially
Cosmic Evolution in Brans-Dicke Chameleon Cosmology
We have investigated the Brans-Dicke Chameleon theory of gravity and obtained
exact solutions of the scale factor , scalar field , an
arbitrary function which interact with the matter Lagrangian in the
action of the Brans-Dicke Chameleon theory and potential for
different epochs of the cosmic evolution. We plot the functions ,
, and for different values of the Brans-Dicke
parameter. In our models, there is no accelerating solution, only decelerating
one with . The physical cosmological distances have been investigated
carefully. Further the statefinder parameters pair and deceleration parameter
are discussed.Comment: To be appear in "The European Physical Journal - Plus (EPJ
Plus)",Extended version,15 pages, 17eps figure
- …