4,909 research outputs found
RMD-QOSM: The NSIS Quality-of-Service Model for Resource Management in Diffserv
This document describes a Next Steps in Signaling (NSIS) Quality-of- Service (QoS) Model for networks that use the Resource Management in Diffserv (RMD) concept. RMD is a technique for adding admission control and preemption function to Differentiated Services (Diffserv) networks. The RMD QoS Model allows devices external to the RMD network to signal reservation requests to Edge nodes in the RMD network. The RMD Ingress Edge nodes classify the incoming flows into traffic classes and signals resource requests for the corresponding traffic class along the data path to the Egress Edge nodes for each flow. Egress nodes reconstitute the original requests and continue forwarding them along the data path towards the final destination. In addition, RMD defines notification functions to indicate overload situations within the domain to the Edge nodes
Challenges in the Discovery and Characterization of Magnetic Intermetallics
The crystal growth and characterization of four families of compounds, LnFeSb3 (Ln = Pr, Nd, Sm, Gd, and Tb) and CeCo(Sb, Sn)3, Ln2Fe4Sb5 (Ln = La – Nd and Sm), LnCu2(Al,Si)5 (Ln = La and Ce), and Ln(Cu,Al,Ga)13 (Ln = La – Pr and Eu), are presented in this dissertation. Special emphasis is placed on describing their structure-magnetic properties correlations. Discoveries and studies of these systems were motivated by their structurally related predecessors, which are comprised of complex structural subunits and exhibit unusual physical properties. The magnetic behaviors exhibited by a selection of these intermetallics include the large magnetoresistances and varying degrees of magnetic anisotropy displayed by PrFeSb3 and NdFeSb3, spin glass behavior observed in the low temperature magnetic susceptibility measurements of La2Fe4Sb5, and the ferromagnetic and moderate magnetocaloric effects observed for Eu(Cu,Al,Ga)13 and Eu(Cu,Al)13. These materials are diverse and beautifully illustrate the complexity of the field of magnetism. Chapter 1 describes the motivations behind the explorations of the abovementioned phase spaces. X-ray and neutron scattering, magnetism, the magnetocaloric effect, and the origins of enhanced electron mass behavior will be reviewed. Additionally, this chapter serves to link these projects. Subsequent chapters provide an in-depth analysis of the structure-property correlations for each system which have been elucidated by their synthesis, structural determinations, and physical properties measurements
Emergence of foams from the breakdown of the phase field crystal model
The phase field crystal (PFC) model captures the elastic and topological
properties of crystals with a single scalar field at small undercooling. At
large undercooling, new foam-like behavior emerges. We characterize this foam
phase of the PFC equation and propose a modified PFC equation that may be used
for the simulation of foam dynamics. This minimal model reproduces von
Neumann's rule for two-dimensional dry foams, and Lifshitz-Slyozov coarsening
for wet foams. We also measure the coordination number distribution and find
that its second moment is larger than previously-reported experimental and
theoretical studies of soap froths, a finding that we attribute to the wetness
of the foam increasing with time.Comment: 4 pages, 4 figure
Virus Sharing, Genetic Sequencing, and Global Health Security
The WHO’s Pandemic Influenza Preparedness (PIP) Framework was a milestone global agreement designed to promote the international sharing of biological samples to develop vaccines, while that ensuring poorer countries would have access to those vaccines. Since the PIP Framework was negotiated, scientists have developed the capacity to use genetic sequencing data (GSD) to develop synthetic viruses rapidly for product development of life-saving technologies in a time-sensitive global emergency—threatening to unravel the Framework. Access to GSD may also have major implications for biosecurity, biosafety, and intellectual property (IP).
By rendering the physical transfer of viruses antiquated, GSD may also undermine the effectiveness of the PIP Framework itself, with disproportionate impacts on poorer countries. We examine the changes that need to be made to the PIP Framework to address the growing likelihood that GSD might be shared instead of physical virus samples. We also propose that the international community harness this opportunity to expand the scope of the PIP Framework beyond only influenza viruses with pandemic potential.
In light of non-influenza pandemic threats such as the Middle East Respiratory Syndrome (MERS) and Ebola, we call for an international agreement on the sharing of the benefits of research – such as vaccines and treatments – for other infectious diseases to ensure not only a more secure and healthy world, but also a more just world, for humanity
Prdx Overexpression in Tumor Tissue of Breast Cancer Patients
Peroxiredoxin (Prdx) proteins are evolutionarily conserved thiol-specific antioxidant enzymes that reduce various cellular peroxides, protecting cells from oxidative damage. Prdxs also have been demonstrated to play an important role in regulating redox-sensitive cell signaling in a number of cell processes. Prdxs have been implicated in cancer biology, and are upregulated in many cancers including breast cancer, as well as several breast cancer cell lines. To explore the entire Prdx family in breast cancer, we analyzed the expression of all six Prdx proteins in breast tumor tissue and adjacent normal breast tissue from 14 patients. We found that most patients have a marked elevation of Prdx expression in tumor tissue, with many patients overexpressing multiple Prdxs. Specifically, we found that 71% of patients overexpress Prdx1, 50% overexpress Prdx2, 64% overexpress Prdx3, and 57% overexpress Prdx4. In contrast, Prdx5 and Prdx6 are elevated in a minority of patients. We found no association, however, between the incidence of Prdx overexpression and tumor grade in this study. Our findings provide further evidence for Prdx elevation in breast cancer using matched patient samples, and support the notion that Prdx upregulation may provide a survival advantage to breast cancer cells, and other cancer cells
A Triangular Tessellation Scheme for the Adsorption Free Energy at the Liquid-Liquid Interface: Towards Non-Convex Patterned Colloids
We introduce a new numerical technique, namely triangular tessellation, to
calculate the free energy associated with the adsorption of a colloidal
particle at a flat interface. The theory and numerical scheme presented here
are sufficiently general to handle non-convex patchy colloids with arbitrary
surface patterns characterized by a wetting angle, e.g., amphiphilicity. We
ignore interfacial deformation due to capillary, electrostatic, or
gravitational forces, but the method can be extended to take such effects into
account. It is verified that the numerical method presented is accurate and
sufficiently stable to be applied to more general situations than presented in
this paper. The merits of the tessellation method prove to outweigh those of
traditionally used semi-analytic approaches, especially when it comes to
generality and applicability.Comment: 21 pages, 11 figures, 0 table
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