9,635 research outputs found
Zero-error Slepian-Wolf Coding of Confined Correlated Sources with Deviation Symmetry
In this paper, we use linear codes to study zero-error Slepian-Wolf coding of
a set of sources with deviation symmetry, where the sources are generalization
of the Hamming sources over an arbitrary field. We extend our previous codes,
Generalized Hamming Codes for Multiple Sources, to Matrix Partition Codes and
use the latter to efficiently compress the target sources. We further show that
every perfect or linear-optimal code is a Matrix Partition Code. We also
present some conditions when Matrix Partition Codes are perfect and/or
linear-optimal. Detail discussions of Matrix Partition Codes on Hamming sources
are given at last as examples.Comment: submitted to IEEE Trans Information Theor
Advanced architectural descriptors in foams: novel 3D computational methods
This work presents 3D computational strategies aimed at providing foam de-structuration of the basic components of a cellular material (struts and cell walls) offering the possibility of analysing separately the structural elements that play an important role in the physical properties of thee materials. Two different methodologies have been used depending on the topological similarities existing between the struts and cell walls: 3D erosion-dilation procedure (thick struts) and solid classification algorithm (thin struts). In a second step, analysis of cell walls is performed in order to show the advantages of analysing separately the two foams components. Particularly, cell wall thickness distribution reveals differences that could not be found prior to the de-structuration
Erythropoietin inhibits chemotherapy-induced cell death and promotes a senescence-like state in leukemia cells
There are conflicting reports on the adverse effects of erythropoietin (EPO) for the management of cancer-associated anemia. The recognition that erythropoietin receptors (EPORs) are expressed outside the erythroid lineage and concerns that erythropoiesis-stimulating agents (ESAs) may cause tumors to grow and increase the risk of venous thromboembolism have resulted in substantially fewer cancer patients receiving ESA therapy to manage myelosuppressive chemotherapy. In this study, we found that EPO suppresses p53-dependent apoptosis induced by genotoxic (daunorubicin, doxorubicin, and γ-radiation) and non-genotoxic (nutlin-3a) agents and induces a senescence-like state in myeloid leukemia cells. EPO interferes with stress-dependent Mdm2 downregulation and leads to the destabilization of p53 protein. EPO selectively modulates the expression of p53 target genes in response to DNA damage preventing the induction of a number of noncoding RNAs (ncRNAs) previously associated with p53-dependent apoptosis. EPO also enhances the expression of the cyclin-dependent kinase inhibitor p21WAF1 and promotes recruitment of p53 to the p21 promoter. In addition, EPO antagonizes Mcl-1 protein degradation in daunorubicin-treated cells. Hence, EPO signaling targets Mcl-1 expression and the p53-Mdm2 network to promote tumor cell survival.York University Librarie
Canonical Generations and the British Left: The Narrative Construction of the Miners’ Strike 1984–85
‘Generations’ have been invoked to describe a variety of social and cultural relationships, and to understand the development of self-conscious group identity. Equally, the term can be an applied label and politically useful construct; generations can be retrospectively produced. Drawing on the concept of ‘canonical generations’ – those whose experiences come to epitomise an event of historic and symbolic importance – this article examines the narrative creation and functions of ‘generations’ as collective memory shapes and re-shapes the desire for social change. Building a case study of the canonical role of the miners’ strike of 1984–85 in the narrative history of the British left, it examines the selective appropriation and transmission of the past in the development of political consciousness. It foregrounds the autobiographical narratives of activists who, in examining and legitimising their own actions and prospects, (re)produce a ‘generation’ in order to create a relatable and useful historical understanding
Festuca dertosensis (Poaceae), an overlooked fescue from the NE Iberian Peninsula
A new species of Festuca L. (Poaceae) is described from the southern mountains of Tarragona (Catalonia, Spain). The new taxon belongs to the F. rubra aggregate, and superficially resembles plants of the F. trichophylla group. Its leaf anatomy, however, suggests a closer relationship with F. rubra and, in particular, F. heterophylla. Although sharing some features with F. paucispicula, a sympatric taxon, there are sufficient differences to warrant its separation from this local endemic. A comparative table and key are provided to assist in the identification of this overlooked fescue, and its relationship to other species present in the area is discussed, with special attention paid to species sharing a similar distribution. Mitosis studies have been carried out to determine the chromosome number, and the results suggest a decaploid, with a chromosome number of 2n = c. 70
Characterizing and Propagating Modeling Uncertainties in Photometrically-Derived Redshift Distributions
The uncertainty in the redshift distributions of galaxies has a significant
potential impact on the cosmological parameter values inferred from multi-band
imaging surveys. The accuracy of the photometric redshifts measured in these
surveys depends not only on the quality of the flux data, but also on a number
of modeling assumptions that enter into both the training set and SED fitting
methods of photometric redshift estimation. In this work we focus on the
latter, considering two types of modeling uncertainties: uncertainties in the
SED template set and uncertainties in the magnitude and type priors used in a
Bayesian photometric redshift estimation method. We find that SED template
selection effects dominate over magnitude prior errors. We introduce a method
for parameterizing the resulting ignorance of the redshift distributions, and
for propagating these uncertainties to uncertainties in cosmological
parameters.Comment: 13 pages, 12 figures, version published in Ap
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