On Broken Triangles (CP 2014)

International audienceA binary CSP instance satisfying the broken-triangle property (BTP) can be solved in polynomial time. Unfortunately, in practice, few instances satisfy the BTP. We show that a local version of the BTP allows the merging of domain values in binary CSPs, thus providing a novel polynomial-time reduction operation. Experimental trials on benchmark instances demonstrate a significant decrease in instance size for certain classes of problems. We show that BTP-merging can be generalised to instances with constraints of arbitrary arity. A directional version of the general-arity BTP then allows us to extend the BTP tractable class previously defined only for binary CSP

Beyond Consistency and Substitutability

International audienceElimination of inconsistent values in instances of the constraint satisfaction problem (CSP) conserves all solutions. Elimination of substitutable values conserves at least one solution. We show that certain values which are neither inconsistent nor substitutable can also be deleted while conserving at least one solution. This allows us to state novel rules for the elimination of values in binary CSP. From a practical point of view, we show that one such rule can be applied in the same asymptotic time complexity as neighbourhood substitution but is strictly stronger. An alternative to the elimination of values from domains is the elimination of variables. We give novel satisfiability-preserving variable elimination operations. In each case we show that if the instance is satisfiable, then a solution to the original instance can always be recovered in low-order polynomial time from a solution to the reduced instance

Evidence for strong evolution in galaxy environmental quenching efficiency between z = 1.6 and z = 0.9

Indexación: Web of Science; Scopus.We analyse the evolution of environmental quenching efficiency, the fraction of quenched cluster galaxies which would be star forming if they were in the field, as a function of redshift in 14 spectroscopically confirmed galaxy clusters with 0.87 < z < 1.63 from the Spitzer Adaptation of the Red-Sequence Cluster Survey. The clusters are the richest in the survey at each redshift. Passive fractions rise from 42-13 +10 per cent at z ~ 1.6 to 80-9 +12 per cent at z ~ 1.3 and 88-3 +4 per cent at z < 1.1, outpacing the change in passive fraction in the field. Environmental quenching efficiency rises dramatically from 16-19 +15 per cent at z ~ 1.6 to 62-15 +21 per cent at z~1.3 and 73-7 +8 per cent at z ≲ 1.1. This work is the first to show direct observational evidence for a rapid increase in the strength of environmental quenching in galaxy clusters at z ~ 1.5, where simulations show cluster-mass haloes undergo non-linear collapse and virialization.https://academic.oup.com/mnrasl/article/465/1/L104/241728

Do we have sufficient information to optimally inform regulatory or other policy decisions about medications containing codeine?

Letter to the editor. Codeine is the most commonly consumed opiate world-wide, with demand having risen 27% during the last decade and with global purchasing peaking at 269 tonnes in 2011 [1]. Although its effects are milder than heroin, its opiate effect means it has misuse and dependence potential. To address the lack of epidemiological data on codeine misuse and dependence, we obtained previously unreported formal drug treatment data involving codeine misuse and dependence from the UK National Drug Treatment Monitoring System (NDTMS), the Irish National Drug Treatment Reporting System (NDTRS) and the South African Community Epidemiology Network on Drug Use (SACENDU)…

Shape Invariant Potential and Semi-Unitary Transformations (SUT) for Supersymmetric Harmonic Oscillator in T4-Space

Constructing the Semi - Unitary Transformation (SUT) to obtain the supersymmetric partner Hamiltonians for a one dimensional harmonic oscillator, it has been shown that under this transformation the supersymmetric partner loses its ground state in T^{4}- space while its eigen functions constitute a complete orthonormal basis in a subspace of full Hilbert space. Keywords: Supersymmetry, Superluminal Transformations, Semi Unitary Transformations. PACS No: 14.80L

Superscaling analysis of the Coulomb Sum Rule in quasielastic electron-nucleus scattering

The Coulomb sum rule for inclusive quasielastic electron scattering in $^{12}$C, $^{40}$Ca and $^{56}$Fe is analyzed based on scaling and superscaling properties. Results obtained in the relativistic impulse approximation with various descriptions of the final state interactions are shown. A comparison with experimental data measured at Bates and Saclay is provided. The theoretical description based on strong scalar and vector terms present in the relativistic mean field, which has been shown to reproduce the experimental asymmetric superscaling function, leads to results that are in fair agreement with Bates data while it sizeably overestimates Saclay data. We find that the Coulomb sum rule for a momentum transfer $q\geq 500$ $MeV/c$ saturates to a value close to 0.9, being very similar for the three nuclear systems considered. This is in accordance with Bates data, which indicates that these show no significative quenching in the longitudinal response.Comment: 22 pages, 6 figures. To be published in Phys. Lett.

Discovery of functionally selective C5aR2 ligands: novel modulators of C5a signalling.

The complement cascade is comprised of a highly sophisticated network of innate immune proteins that are activated in response to invading pathogens or tissue injury. The complement activation peptide, C5a, binds two seven transmembrane receptors, namely the C5a receptor 1 (C5aR1) and C5a receptor 2 (C5aR2, or C5L2). C5aR2 is a non-G-protein-signalling receptor whose biological role remains controversial. Some of this controversy arises owing to the lack of selective ligands for C5aR2. In this study, a library of 61 peptides based on the C-terminus of C5a was assayed for the ability to selectively modulate C5aR2 function. Two ligands (P32 and P59) were identified as functionally selective C5aR2 ligands, exhibiting selective recruitment of β-arrestin 2 via C5aR2, partial inhibition of C5a-induced ERK1/2 activation and lipopolysaccharide-stimulated interleukin-6 release from human monocyte-derived macrophages. Importantly, neither ligand could induce ERK1/2 activation or inhibit C5a-induced ERK1/2 activation via C5aR1 directly. Finally, P32 inhibited C5a-mediated neutrophil mobilisation in wild-type, but not C5aR2(-/-) mice. These functionally selective ligands for C5aR2 are novel tools that can selectively modulate C5a activity in vitro and in vivo, and thus will be valuable tools to interrogate C5aR2 function.Immunology and Cell Biology advance online publication, 17 May 2016; doi:10.1038/icb.2016.43

Percutaneous vertebroplasty is not a risk factor for new osteoporotic compression fractures: results from VERTOS II

Background and purpose: Pv is increasingly used as treatment for osteoporotic vcfs. However, controversy exists as to whether pv increases the risk for new vcfs during follow-up. The purpose of our research was to assess the incidence of new vcfs in patients with acute vcfs randomized to pv and conservative therapy. Materials and methods: Vertos ii is a prospective multicenter randomized controlled trial comparing pv with conservative therapy in 202 patients. Incidence, distribution, and timing of new vcfs during follow-up were assessed from spine radiographs. In addition, further height loss during follow-up of treated vcfs was measured. Results: After a mean follow-up of 11.4 Months (Median, 12.0; Range, 1-24 months), 18 New vcfs occurred in 15 of 91 patients after pv and 30 new vcfs in 21 of 85 patients after conservative therapy. This difference was not significant (P = .44). There was no higher fracture risk for adjacent-versus-distant vertebrae. Mean time to new vcf was 16.2 Months after pv and 17.8 Months after conservative treatment (Logrank, p = .45). The baseline number of vcfs was the only risk factor for occurrence (Or, 1.43; 95% Ci, 1.05-1.95) And number (P = .01) Of new vcfs. After conservative therapy, further height loss of treated vertebrae occurred more frequently (35 Of 85 versus 11 of 91 patients, p < .001) And was more severe (P < .001) Than after pv. Conclusions: Incidence of new vcfs was not different after pv compared with conservative therapy after a mean of 11.4 Months' follow-up. The only risk factor for new vcfs was the number of vcfs at baseline. Pv contributed to preservation of stature by decreasing both the incidence and severity of further height loss in treated vertebrae

True Superconductivity in a 2D "Superconducting-Insulating" System

We present results on disordered amorphous films which are expected to undergo a field-tuned Superconductor-Insulator Transition. Based on low-field data and I-V characteristics, we find evidence of a low temperature Metal-to-Superconductor transition. This transition is characterized by hysteretic magnetoresistance and discontinuities in the I-V curves. The metallic phase just above the transition is different from the "Fermi Metal" before superconductivity sets in.Comment: 3 pages, 4 figure

Meson Exchange Currents in (e,e'p) recoil polarization observables

A study of the effects of meson-exchange currents and isobar configurations in $A(\vec{e},e'\vec{p})B$ reactions is presented. We use a distorted wave impulse approximation (DWIA) model where final-state interactions are treated through a phenomenological optical potential. The model includes relativistic corrections in the kinematics and in the electromagnetic one- and two-body currents. The full set of polarized response functions is analyzed, as well as the transferred polarization asymmetry. Results are presented for proton knock-out from closed-shell nuclei, for moderate to high momentum transfer.Comment: 44 pages, 18 figures. Added physical arguments explaining the dominance of OB over MEC, and a summary of differences with previous MEC calculations. To be published in PR