16,103 research outputs found
Growth rates for subclasses of Av(321)
Pattern classes which avoid 321 and other patterns are shown to have the same growth rates as similar (but strictly larger) classes obtained by adding articulation points to any or all of the other patterns. The method of proof is to show that the elements of the latter classes can be represented as bounded merges of elements of the original class, and that the bounded merge construction does not change growth rates
Siting prisons, sighting communities: geographies of objection in a planning process
This paper reviews the planning process for a Scottish prison located near a former mining village. Analysing the letters of objection submitted by residents offers an opportunity to explore local views about prison and community and to relate these to the unique social and spatial history of the area. The planning process itself structured how residents were able to express themselves and defined what counted as a relevant objection. After deconstructing this process, the paper then restores and uses as a framework for analysis three geographies of objection stripped from local responses to the development proposal: the emotional, temporal, and spatial. Emotional expressions of objection added intensity and gave meaning to claims about the historical decline of the region and also conveyed a deep sense of the proposed building site as a lived space. Particular grounds of opposition—over fear of strangers, the fragility of a local orchid, and the pollution from mining—provide an opportunity to explore the complex nature of place meaning and community identity, ultimately leading to a conclusion that the meaning of place is always in flux. The paper argues that Simmel’s classic concept of the stranger, as the outsider who comes to stay, offers a useful analytic in understanding how the quality of proximal remoteness that prisons and other unwanted developments constitute participates in a constantly evolving sense of the local
Space Shuttle Propulsion Systems Plume Modeling and Simulation for the Lift-Off Computational Fluid Dynamics Model
This paper details advances being made in the development of Reynolds-Averaged Navier-Stokes numerical simulation tools, models, and methods for the integrated Space Shuttle Vehicle at launch. The conceptual model and modeling approach described includes the development of multiple computational models to appropriately analyze the potential debris transport for critical debris sources at Lift-Off. The conceptual model described herein involves the integration of propulsion analysis for the nozzle/plume flow with the overall 3D vehicle flowfield at Lift-Off. Debris Transport Analyses are being performed using the Shuttle Lift-Off models to assess the risk to the vehicle from Lift-Off debris and appropriately prioritized mitigation of potential debris sources to continue to reduce vehicle risk. These integrated simulations are being used to evaluate plume-induced debris environments where the multi-plume interactions with the launch facility can potentially accelerate debris particles toward the vehicle
Frontal Gray Matter Reduction After Breast Cancer Chemotherapy and Association With Executive Symptoms: A Replication and Extension Study
poster abstractCognitive changes related to cancer and its treatment have been intensely studied, and neuroimaging has begun to demonstrate brain correlates of these changes. We recently reported structural brain changes in a prospective longitudinal cohort of breast cancer patients. Decreased gray matter density, particularly in frontal regions, was detected one month after completion of chemotherapy and partially recovered over the next year. These findings helped confirm a neural basis for the cognitive symptoms reported by many prior studies, which most commonly involve executive and memory processes in which the frontal lobes are a critical component of underlying neural circuitry. Here we present data from an independent, larger and more demographically diverse cohort that is more generalizable to the breast cancer population. 3.0T MP-RAGE structural MRI scans were acquired on 27 breast cancer patients treated with chemotherapy, 28 breast cancer patients not treated with chemotherapy, and 24 matched healthy controls (all participants were female). Study measures were completed at baseline (after surgery but before radiation, chemotherapy, and/or anti-estrogen treatment) and one month following the completion of chemotherapy, or yoked intervals for the non-chemotherapy and control groups. Gray matter density was examined using optimized voxel-based morphometry (VBM) methods. Results showed decreased frontal gray matter after chemotherapy, as observed in our initial cohort, which was accompanied by self-reported difficulties in executive functioning. These findings provide confirmatory evidence of frontal morphometric changes that may be a pathophysiological basis for cancer and treatment-related cognitive dysfunction. Ongoing research into individual risk factors for such changes will be critical for development of treatment and prevention strategies
The XIIIth Banff Conference on Allograft Pathology: The Banff 2015 Heart Meeting Report: Improving Antibody-Mediated Rejection Diagnostics: Strengths, Unmet Needs, and Future Directions.
The 13th Banff Conference on Allograft Pathology was held in Vancouver, British Columbia, Canada from October 5 to 10, 2015. The cardiac session was devoted to current diagnostic issues in heart transplantation with a focus on antibody-mediated rejection (AMR) and small vessel arteriopathy. Specific topics included the strengths and limitations of the current rejection grading system, the central role of microvascular injury in AMR and approaches to semiquantitative assessment of histopathologic and immunophenotypic indicators, the role of AMR in the development of cardiac allograft vasculopathy, the important role of serologic antibody detection in the management of transplant recipients, and the potential application of new molecular approaches to the elucidation of the pathophysiology of AMR and potential for improving the current diagnostic system. Herein we summarize the key points from the presentations, the comprehensive, open and wide-ranging multidisciplinary discussion that was generated, and considerations for future endeavors
Photometric Accretion Signatures Near the Substellar Boundary
Multi-epoch imaging of the Orion equatorial region by the Sloan Digital Sky
Survey has revealed that significant variability in the blue continuum persists
into the late-M spectral types, indicating that magnetospheric accretion
processes occur below the substellar boundary in the Orion OB1 association. We
investigate the strength of the accretion-related continuum veiling by
comparing the reddening-invariant colors of the most highly variable stars
against those of main sequence M dwarfs and evolutionary models. A gradual
decrease in the g band veiling is seen for the cooler and less massive members,
as expected for a declining accretion rate with decreasing mass. We also see
evidence that the temperature of the accretion shock decreases in the very low
mass regime, reflecting a reduction in the energy flux carried by the accretion
columns. We find that the near-IR excess attributed to circumstellar disk
thermal emission drops rapidly for spectral types later than M4. This is likely
due to the decrease in color contrast between the disk and the cooler stellar
photosphere. Since accretion, which requires a substantial stellar magnetic
field and the presence of a circumstellar disk, is inferred for masses down to
0.05 Msol we surmise that brown dwarfs and low mass stars share a common mode
of formation.Comment: 37 pages, 14 figures, accepted by A
Is a combination of varenicline and nicotine patch more effective in helping smokers quit than varenicline alone? A randomised controlled trial
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Growth dynamics and the evolution of cooperation in microbial populations
Microbes providing public goods are widespread in nature despite running the
risk of being exploited by free-riders. However, the precise ecological factors
supporting cooperation are still puzzling. Following recent experiments, we
consider the role of population growth and the repetitive fragmentation of
populations into new colonies mimicking simple microbial life-cycles.
Individual-based modeling reveals that demographic fluctuations, which lead to
a large variance in the composition of colonies, promote cooperation. Biased by
population dynamics these fluctuations result in two qualitatively distinct
regimes of robust cooperation under repetitive fragmentation into groups.
First, if the level of cooperation exceeds a threshold, cooperators will take
over the whole population. Second, cooperators can also emerge from a single
mutant leading to a robust coexistence between cooperators and free-riders. We
find frequency and size of population bottlenecks, and growth dynamics to be
the major ecological factors determining the regimes and thereby the
evolutionary pathway towards cooperation.Comment: 26 pages, 6 figure
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