Axiomatic Characterization of the Median and Antimedian Functions on Cocktail-Party Graphs and Complete Graphs

__Abstract__ A median (antimedian) of a profile of vertices on a graph $G$ is a vertex that minimizes (maximizes) the remoteness value, that is, the sum of the distances to the elements in the profile. The median (or antimedian) function has as output the set of medians (antimedians) of a profile. It is one of the basic models for the location of a desirable (or obnoxious) facility in a network. The median function is well studied. For instance it has been characterized axiomatically by three simple axioms on median graphs. The median function behaves nicely on many classes of graphs. In contrast the antimedian function does not have a nice behavior on most classes. So a nice axiomatic characterization may not be expected. In this paper an axiomatic characterization is obtained for the median and antimedian functions on complete graphs minus a perfect matching (also known as cocktail-party graphs). In addition a characterization of the antimedian function on complete graphs is presented

Axiomatic Characterization of the Median and Antimedian Function on a Complete Graph minus a Matching

__Abstract__ A median (antimedian) of a profile of vertices on a graph G is a vertex that minimizes (maximizes) the sum of the distances to the elements in the profile. The median (antimedian) function has as output the set of medians (antimedians) of a profile. It is one of the basic models for the location of a desirable (obnoxious) facility in a network. The median function is well studied. For instance it has been characterized axiomatically by three simple axioms on median graphs. The median function behaves nicely on many classes of graphs. In contrast the antimedian function does not have a nice behavior on most classes. So a nice axiomatic characterization may not be expected. In this paper an axiomatic characterization is obtained for the median and antimedian function on complete graphs minus a matching

Spatial polarization modulators: distinguishing diffraction effects from spatial polarization modulation

Are we alone? In our quest to find life beyond Earth, we use our own planet to develop and verify new methods and techniques to remotely detect life. Our Life Signature Detection polarimeter (LSDpol), a snapshot full-Stokes spectropolarimeter to be deployed in the field and in space, looks for signals of life on Earth by sensing the linear and circular polarization states of reflected light. Examples of these biosignatures are linear polarization resulting from O2-A band and vegetation, e.g. the Red edge and the Green bump, as well as circular polarization resulting from the homochirality of biotic molecules. LSDpol is optimized for sensing circular polarization. To this end, LSDpol employs a spatial light modulator in the entrance slit of the spectrograph, a liquid-crystal quarter-wave retarder where the fast axis rotates as a function of slit position. The original design of LSDpol implemented a dual-beam spectropolarimeter by combining a quarter-wave plate with a polarization grating. Unfortunately, this design causes significant linear-to-circular cross-talk. In addition, it revealed spurious polarization modulation effects. Here, we present numerical simulations that illustrate how Fresnel diffraction effects can create these spurious modulations. We verified the simulations with accurate polarization state measurements in the lab using 100% linearly and circularly polarized light.Instrumentatio

Spin glass overlap barriers in three and four dimensions

For the Edwards-Anderson Ising spin-glass model in three and four dimensions (3d and 4d) we have performed high statistics Monte Carlo calculations of those free-energy barriers $F^q_B$ which are visible in the probability density $P_J(q)$ of the Parisi overlap parameter $q$. The calculations rely on the recently introduced multi-overlap algorithm. In both dimensions, within the limits of lattice sizes investigated, these barriers are found to be non-self-averaging and the same is true for the autocorrelation times of our algorithm. Further, we present evidence that barriers hidden in $q$ dominate the canonical autocorrelation times.Comment: 20 pages, Latex, 12 Postscript figures, revised version to appear in Phys. Rev.

Increased numbers of dendritic cells in the bronchial mucosa of atopic asthmatic patients: Downregulation by inhaled corticosteroids

Background. Dendritic cells (DC) are the most potent antigen-presenting cells (APC) and stimulators of T cells. Dendritic cells are also likely to be essential for the initiation of allergic immune responses in the lung. However, there are not many data on the presence of dendritic cells in the airways of patients with atopic asthma and on the effects of corticosteroid-treatment on such dendritic cells. Objective. We investigated the distribution of dendritic cells in the bronchial epithelium and mucosa of 16 non-smoking atopic asthmatic patients and eight healthy control subjects using detailed immunohistochemistry (CD1a, HLA-DR, L25 as markers for dendritic cells). Methods. Eleven asthmatics were treated for 2.5 years with bronchodilators only and five with bronchodilators and inhaled beclomethasone dipropionate (BDP), 800 μg daily. The patients were randomly sampled from a double-blind multicentre study. Results. There were higher numbers of CD1a+ DC (P = 0.003), L25+ DC (P = 0.002) and HLA-DR expression (P = 0.042) in the bronchial mucosa of asthmatic patients compared with healthy controls. After 2.5 years of treatment, we found a significant increase in flow expiratory volume in 1 second (FEV1) (P = 0.009) and a significant decrease in hyperresponsiveness (PC20 histamine) (P = 0.013) in the corticosteroid group (n = 5) compared with the bronchodilator group (n = 11). This clinical improvement in the corticosteroid-treated group was accompanied by significantly lower numbers of CD1a+ DC (P=0.008), and HLA-DR expression (P=0.028) in the bronchial mucosa than in the bronchodilator-treated group. Conclusion. Our data suggest that dendritic cells are involved in asthmatic inflammation and that corticosteroids may downregulate the number of dendritic

Total Chemical Synthesis of SUMO and SUMO-Based Probes for Profiling the Activity of SUMO-Specific Proteases

Chemical Immunolog

Coeliac disease-associated risk variants in TNFAIP3 and REL implicate altered NF-kappaB signalling

Objective: Our previous coeliac disease genome-wide association study (GWAS) implicated risk variants in the human leucocyte antigen (HLA) region and eight novel risk regions. To identify more coeliac disease loci, we selected 458 single nucleotide polymorphisms (SNPs) that showed more modest association in the GWAS for genotyping and analysis in four independent cohorts. Design: 458 SNPs were assayed in 1682 cases and 3258 controls from three populations (UK, Irish and Dutch). We combined the results with the original GWAS cohort (767 UK cases and 1422 controls); six SNPs showed association with p Results: We identified two novel coeliac disease risk regions: 6q23.3 (OLIG3-TNFAIP3) and 2p16.1 (REL), both of which reached genome-wide significance in the combined analysis of all 2987 cases and 5273 controls (rs2327832 p= 1.3x10(-08), and rs842647 p= 5.26x10(-07)). We investigated the expression of these genes in the RNA isolated from biopsies and from whole blood RNA. We did not observe any changes in gene expression, nor in the correlation of genotype with gene expression. Conclusions: Both TNFAIP3 (A20, at the protein level) and REL are key mediators in the nuclear factor kappa B (NF-kappa B) inflammatory signalling pathway. For the first time, a role for primary heritable variation in this important biological pathway predisposing to coeliac disease has been identified. Currently, the HLA risk factors and the 10 established non-HLA risk factors explain similar to 40% of the heritability of coeliac disease

BB flavour tagging using charm decays at the LHCb experiment

An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes $B^+ \to J/\psi \, K^+$ and $B^0 \to J/\psi \, K^{*0}$ using $3.0\mathrm{\,fb}^{-1}$ of data collected by the LHCb experiment at $pp$ centre-of-mass energies of $7\mathrm{\,TeV}$ and $8\mathrm{\,TeV}$. Its tagging power on these samples of $B \to J/\psi \, X$ decays is $(0.30 \pm 0.01 \pm 0.01) \%$.Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm

Four simple recommendations to encourage best practices in research software [version 1; referees: awaiting peer review]

Scientific research relies on computer software, yet software is not always developed following practices that ensure its quality and sustainability. This manuscript does not aim to propose new software development best practices, but rather to provide simple recommendations that encourage the adoption of existing best practices. Software development best practices promote better quality software, and better quality software improves the reproducibility and reusability of research. These recommendations are designed around Open Source values, and provide practical suggestions that contribute to making research software and its source code more discoverable, reusable and transparent. This manuscript is aimed at developers, but also at organisations, projects, journals and funders that can increase the quality and sustainability of research software by encouraging the adoption of these recommendations. Keyword

Multifunctional Magnetic-fluorescent Nanocomposites for Biomedical Applications

Nanotechnology is a fast-growing area, involving the fabrication and use of nano-sized materials and devices. Various nanocomposite materials play a number of important roles in modern science and technology. Magnetic and fluorescent inorganic nanoparticles are of particular importance due to their broad range of potential applications. It is expected that the combination of magnetic and fluorescent properties in one nanocomposite would enable the engineering of unique multifunctional nanoscale devices, which could be manipulated using external magnetic fields. The aim of this review is to present an overview of bimodal “two-in-one” magnetic-fluorescent nanocomposite materials which combine both magnetic and fluorescent properties in one entity, in particular those with potential applications in biotechnology and nanomedicine. There is a great necessity for the development of these multifunctional nanocomposites, but there are some difficulties and challenges to overcome in their fabrication such as quenching of the fluorescent entity by the magnetic core. Fluorescent-magnetic nanocomposites include a variety of materials including silica-based, dye-functionalised magnetic nanoparticles and quantum dots-magnetic nanoparticle composites. The classification and main synthesis strategies, along with approaches for the fabrication of fluorescent-magnetic nanocomposites, are considered. The current and potential biomedical uses, including biological imaging, cell tracking, magnetic bioseparation, nanomedicine and bio- and chemo-sensoring, of magnetic-fluorescent nanocomposites are also discussed