205 research outputs found
Dissipative dynamics of vortex arrays in trapped Bose-condensed gases: neutron stars physics on K scale
We develop a theory of dissipative dynamics of large vortex arrays in trapped
Bose-condensed gases. We show that in a static trap the interaction of the
vortex array with thermal excitations leads to a non-exponential decay of the
vortex structure, and the characteristic lifetime depends on the initial
density of vortices. Drawing an analogy with physics of pulsar glitches, we
propose an experiment which employs the heating of the thermal cloud in the
course of the decay of the vortex array as a tool for a non-destructive study
of the vortex dynamics.Comment: 4 pages, revtex; revised versio
Collective modes of a quasi two-dimensional Bose condensate in large gas parameter regime
We have theoretically studied the collective modes of a quasi two-dimensional
(Q2D) Bose condensate in the large gas parameter regime by using a formalism
which treats the interaction energy beyond the mean-field approximation. In the
calculation we use the perturbative expansion for the interaction energy by
incorporating the Lee, Huang and Yang (LHY) correction term. The results show
that incorporation of this higher order term leads to detectable modifications
in the mode frequencies.Comment: 10 pages, 2 figure
On the Location of the Gamma-ray Emission in the 2008 Outburst in the BL Lacertae Object AO 0235+164 through Observations across the Electromagnetic Spectrum
We present observations of a major outburst at centimeter, millimeter,
optical, X-ray, and gamma-ray wavelengths of the BL Lacertae object AO
0235+164. We analyze the timing of multi-waveband variations in the flux and
linear polarization, as well as changes in Very Long Baseline Array (VLBA)
images at 7mm with 0.15 milliarcsecond resolution. The association of the
events at different wavebands is confirmed at high statistical significance by
probability arguments and Monte-Carlo simulations. A series of sharp peaks in
optical linear polarization, as well as a pronounced maximum in the 7 mm
polarization of a superluminal jet knot, indicate rapid fluctuations in the
degree of ordering of the magnetic field. These results lead us to conclude
that the outburst occurred in the jet both in the quasi-stationary "core" and
in the superluminal knot, both parsecs downstream of the supermassive black
hole. We interpret the outburst as a consequence of the propagation of a
disturbance, elongated along the line of sight by light-travel time delays,
that passes through a standing recollimation shock in the core and propagates
down the jet to create the superluminal knot. The multi-wavelength light curves
vary together on long time-scales (months/years), but the correspondence is
poorer on shorter time-scales. This, as well as the variability of the
polarization and the dual location of the outburst, agrees with the
expectations of a multi-zone emission model in which turbulence plays a major
role in modulating the synchrotron and inverse Compton fluxes.Comment: Accepted for Publication in the Astrophysical Journal Letters. 7
pages (including 5 figures). Minor corrections with regard to previous
version, as proposed by the refere
A combined risk analysis approach for complex dam-levee systems
[EN] In many areas of the world, dams and levees are built to reduce the likelihood of flooding. However, if they fail, the result can be catastrophic flooding beyond what would happen if they did not exist. Therefore, understanding the risk reduced by the dam or levee, as well as any risk imposed by these flood defences is of high importance when determining the appropriate risk reduction investment strategy. This paper describes an approach for quantifying and analysing risk for complex dam-levee systems, and its application to a real case study. The basis behind such approach rely on the potential of event tree modelling to analyse risk from multiple combinations of load-system response-consequence' events, tested by the authors for a real case study. The combined approach shows how the contribution to system risk of each sub-system can be assessed. It also describes how decisions on risk mitigation measures, at the individual asset scale, can and should be informed in terms of how they impact the overall system risk.This work was supported by Spanish Ministry of Economy and Competitiveness (MINECO) [BIA 2013-48157-C2-1-R].Castillo-RodrÃguez, J.; Needham, J.; Morales Torres, A.; Escuder Bueno, I. (2017). A combined risk analysis approach for complex dam-levee systems. Structure and Infrastructure Engineering. 13(12):1624-1638. https://doi.org/10.1080/15732479.2017.1314514S16241638131
Comparative evidence for a link between Peyer's patch development and susceptibility to transmissible spongiform encephalopathies
BACKGROUND: Epidemiological analyses indicate that the age distribution of natural cases of transmissible spongiform encephalopathies (TSEs) reflect age-related risk of infection, however, the underlying mechanisms remain poorly understood. Using a comparative approach, we tested the hypothesis that, there is a significant correlation between risk of infection for scrapie, bovine spongiform encephalopathy (BSE) and variant CJD (vCJD), and the development of lymphoid tissue in the gut. METHODS: Using anatomical data and estimates of risk of infection in mathematical models (which included results from previously published studies) for sheep, cattle and humans, we calculated the Spearman's rank correlation coefficient, r(s), between available measures of Peyer's patch (PP) development and the estimated risk of infection for an individual of the corresponding age. RESULTS: There was a significant correlation between the measures of PP development and the estimated risk of TSE infection; the two age-related distributions peaked in the same age groups. This result was obtained for each of the three host species: for sheep, surface area of ileal PP tissue vs risk of infection, r(s )= 0.913 (n = 19, P < 0.001), and lymphoid follicle density vs risk of infection, r(s )= 0.933 (n = 19, P < 0.001); for cattle, weight of PP tissue vs risk of infection, r(s )= 0.693 (n = 94, P < 0.001); and for humans, number of PPs vs risk of infection, r(s )= 0.384 (n = 46, P = 0.008). In addition, when changes in exposure associated with BSE-contaminated meat were accounted for, the two age-related patterns for humans remained concordant: r(s )= 0.360 (n = 46, P = 0.014). CONCLUSION: Our findings suggest that, for sheep, cattle and humans alike there is an association between PP development (or a correlate of PP development) and susceptibility to natural TSE infection. This association may explain changes in susceptibility with host age, and differences in the age-susceptibility relationship between host species
Dual Organism Transcriptomics of Airway Epithelial Cells Interacting with Conidia of Aspergillus fumigatus
Background
Given the complex nature of the responses that can occur in host-pathogen interactions, dual transcriptomics offers a powerful method of elucidating these interactions during infection. The gene expression patterns of Aspergillus fumigatus conidia or host cells have been reported in a number of previous studies, but each focused on only one of the interacting organisms. In the present study, we profiled simultaneously the transcriptional response of both A. fumigatus and human airway epithelial cells (AECs).
Methodology
16HBE14o- transformed bronchial epithelial cells were incubated with A. fumigatus conidia at 37°C for 6 hours, followed by genome-wide transcriptome analysis using human and fungal microarrays. Differentially expressed gene lists were generated from the microarrays, from which biologically relevant themes were identified. Human and fungal candidate genes were selected for validation, using RT-qPCR, in both 16HBE14o- cells and primary AECs co-cultured with conidia.
Principal Findings
We report that ontologies related to the innate immune response are activated by co-incubation with A. fumigatus condia, and interleukin-6 (IL-6) was confirmed to be up-regulated in primary AECs via RT-qPCR. Concomitantly, A. fumigatus was found to up-regulate fungal pathways involved in iron acquisition, vacuolar acidification, and formate dehydrogenase activity
Clinical management of gastric cancer: results of a multicentre survey
<p>Abstract</p> <p>Background</p> <p>The National Comprehensive Cancer Network clinical practice guidelines in oncology-gastric cancer guidelines have been widely used to provide appropriate recommendations for the treatment of patients with gastric cancer. The aim of this study was to examine the adherence of surgical oncologists, medical oncologists, and radiation oncologists' to the recommended guidelines.</p> <p>Methods</p> <p>A questionnaire asking the treatment options for gastric cancer cases was sent to 394 Chinese oncology specialists, including surgical oncologists, medical oncologists, and radiation oncologists working in hospitals joined in The Western Cooperative Gastrointestinal Oncology Group of China. The questionnaire involved a series of clinical scenarios regarding the interpretation of surgery, neoadjuvant, adjuvant, and advanced treatment planning of gastric cancer.</p> <p>Results</p> <p>Analysis of 358 respondents (91%) showed variations between each specialization and from the recommended guidelines in the management approaches to specific clinical scenarios. The majority of specialists admitted that less than 50% of patients received multidisciplinary evaluation before treatment. The participants gave different responses to questions involving adjuvant, neoadjuvant, and advanced settings, compared to the recommended guidelines.</p> <p>Conclusions</p> <p>These results highlight the heterogeneity of the treatment of gastric cancer. Surgical oncologists, medical oncologists, and radiation oncologists are not adhering to the recommended guidelines.</p
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