4,499 research outputs found
Strichartz estimates for the Schr\"odinger equation on polygonal domains
We prove Strichartz estimates with a loss of derivatives for the
Schr\"odinger equation on polygonal domains with either Dirichlet or Neumann
homogeneous boundary conditions. Using a standard doubling procedure, estimates
the on polygon follow from those on Euclidean surfaces with conical
singularities. We develop a Littlewood-Paley squarefunction estimate with
respect to the spectrum of the Laplacian on these spaces. This allows us to
reduce matters to proving estimates at each frequency scale. The problem can be
localized in space provided the time intervals are sufficiently small.
Strichartz estimates then follow from a result of the second author regarding
the Schr\"odinger equation on the Euclidean cone.Comment: 12 page
Long Range Beam-beam Effects in the LHC
We report on the experience with long-range beam--beam effects in the LHC, in
dedicated studies as well as the experience from operation. Where possible, we
compare the observations with the expectations.Comment: Presented at the ICFA Mini-Workshop on Beam-Beam in Hadron Colliders,
CERN, Geneva, Switzerland, 18-22 March 201
Mode spectrum and temporal soliton formation in optical microresonators
The formation of temporal dissipative solitons in optical microresonators
enables compact, high repetition rate sources of ultra-short pulses as well as
low noise, broadband optical frequency combs with smooth spectral envelopes.
Here we study the influence of the resonator mode spectrum on temporal soliton
formation. Using frequency comb assisted diode laser spectroscopy, the measured
mode structure of crystalline MgF2 resonators are correlated with temporal
soliton formation. While an overal general anomalous dispersion is required, it
is found that higher order dispersion can be tolerated as long as it does not
dominate the resonator's mode structure. Mode coupling induced avoided
crossings in the resonator mode spectrum are found to prevent soliton
formation, when affecting resonator modes close to the pump laser. The
experimental observations are in excellent agreement with numerical simulations
based on the nonlinear coupled mode equations, which reveal the rich interplay
of mode crossings and soliton formation
A para-differential renormalization technique for nonlinear dispersive equations
For \alpha \in (1,2) we prove that the initial-value problem \partial_t
u+D^\alpha\partial_x u+\partial_x(u^2/2)=0 on \mathbb{R}_x\times\mathbb{R}_t;
u(0)=\phi, is globally well-posed in the space of real-valued L^2-functions. We
use a frequency dependent renormalization method to control the strong low-high
frequency interactions.Comment: 42 pages, no figure
Institute of Archaeology & Horn Archaeological Museum Newsletter Volume 23.3
Tall al-\u27Umayri 2002, Larry G. Herr, Douglas R. Clark, and Lawrence T. Geraty
Monson and Master Lecture, Robert D. Bates
Velazquez visits British Museum, Robert D. Bates
Zadok Studies Tablets, Paul J. Ray, Jr.
Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1011/thumbnail.jp
Towards a new theory of practice for community health psychology
The article sets out the value of theorizing collective action from a social science perspective that engages with the messy actuality of practice. It argues that community health psychology relies on an abstract version of Paulo Freire’s earlier writing, the Pedagogy of the Oppressed, which provides scholar-activists with a ‘map’ approach to collective action. The article revisits Freire’s later work, the Pedagogy of Hope, and argues for the importance of developing a ‘journey’ approach to collective action. Theories of practice are discussed for their value in theorizing such journeys, and in bringing maps (intentions) and journeys (actuality) closer together
Air Pollution and Lymphocyte Phenotype Proportions in Cord Blood
Effects of air pollution on morbidity and mortality may be mediated by alterations in immune competence. In this study we examined short-term associations of air pollution exposures with lymphocyte immunophenotypes in cord blood among 1,397 deliveries in two districts of the Czech Republic. We measured fine particulate matter < 2.5 μm in diameter (PM(2.5)) and 12 polycyclic aromatic hydrocarbons (PAHs) in 24-hr samples collected by versatile air pollution samplers. Cord blood samples were analyzed using a FACSort flow cytometer to determine phenotypes of CD3(+) T-lymphocytes and their subsets CD4(+) and CD8(+), CD19(+) B-lymphocytes, and natural killer cells. The mothers were interviewed regarding sociodemographic and lifestyle factors, and medical records were abstracted for obstetric, labor and delivery characteristics. During the period 1994 to 1998, the mean daily ambient concentration of PM(2.5) was 24.8 μg/m(3) and that of PAHs was 63.5 ng/m(3). In multiple linear regression models adjusted for temperature, season, and other covariates, average PAH or PM(2.5) levels during the 14 days before birth were associated with decreases in T-lymphocyte phenotype fractions (i.e., CD3(+) CD4(+), and CD8(+)), and a clear increase in the B-lymphocyte (CD19(+)) fraction. For a 100-ng/m(3) increase in PAHs, which represented approximately two standard deviations, the percentage decrease was −3.3% [95% confidence interval (CI), −5.6 to −1.0%] for CD3(+), −3.1% (95% CI, −4.9 to −1.3%) for CD4(+), and −1.0% (95% CI, −1.8 to −0.2%) for CD8(+) cells. The corresponding increase in the CD19(+) cell proportion was 1.7% (95% CI, 0.4 to 3.0%). Associations were similar but slightly weaker for PM(2.5). Ambient air pollution may influence the relative distribution of lymphocyte immunophenotypes of the fetus
Comparing Open Radical Cystectomy and Robot-assisted Laparoscopic Radical Cystectomy: A Randomized Clinical Trial
Background: Open radical cystectomy (ORC) and urinary diversion in patients with bladder cancer (BCa) are associated with significant perioperative complication risk. Objective: To compare perioperative complications between robot-assisted radical cystectomy (RARC) and ORC techniques. Design, setting, and participants: A prospective randomized controlled trial was conducted during 2010 and 2013 in BCa patients scheduled for definitive treatment by radical cystectomy (RC), pelvic lymph node dissection (PLND), and urinary diversion. Patients were randomized to ORC/PLND or RARC/PLND, both with open urinary diversion. Patients were followed for 90 d postoperatively. Intervention: Standard ORC or RARC with PLND; all urinary diversions were performed via an open approach. Outcome measurements and statistical analysis: Primary outcomes were overall 90-d grade 2-5 complications defined by a modified Clavien system. Secondary outcomes included comparison of high-grade complications, estimated blood loss, operative time, pathologic outcomes, 3-and 6-mo patient-reported quality-of-life (QOL) outcomes, and total operative room and inpatient costs. Differences in binary outcomes were assessed with the chi-square test, with differences in continuous outcomes assessed by analysis of covariance with randomization group as covariate and, for QOL end points, baseline score. Results and limitations: The trial enrolled 124 patients, of whom 118 were randomized and underwent RC/PLND. Sixty were randomized to RARC and 58 to ORC. At 90 d, grade 2-5 complications were observed in 62% and 66% of RARC and ORC patients, respectively (95% confidence interval for difference, -21% to -13%; p = 0.7). The similar rates of grade 2-5 complications at our mandated interim analysis met futility criteria; thus, early closure of the trial occurred. The RARC group had lower mean intraoperative blood loss (p = 0.027) but significantly longer operative time than the ORC group (p \u3c 0.001). Pathologic variables including positive surgical margins and lymph node yields were similar. Mean hospital stay was 8 d in both arms (standard deviation, 3 and 5 d, respectively; p = 0.5). Three-and 6-mo QOL outcomes were similar between arms. Cost analysis demonstrated an advantage to ORC compared with RARC. A limitation is the setting at a single high-volume, referral center; our findings may not be generalizable to all settings. Conclusions: This trial failed to identify a large advantage for robot-assisted techniques over standard open surgery for patients undergoing RC/PLND and urinary diversion. Similar 90-d complication rates, hospital stay, pathologic outcomes, and 3-and 6-mo QOL outcomes were observed regardless of surgical technique. Patient summary: Of 118 patients with bladder cancer who underwent radical cystectomy, pelvic lymph node dissection, and urinary diversion, half were randomized to open surgery and half to robot-assisted laparoscopic surgery. We compared the rate of complications within 90 d after surgery for the open group versus the robotic group and found no significant difference between the two groups. Trial Registration: ClinicalTrials. gov identifier NCT01076387, www.clinicaltrials.gov. (C) 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved
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