Prosthetic Vascular Graft Infection: A Multi-Center Review of Surgical Management

A multi-center retrospective review of major prosthetic graft infection outcomes was undertaken to determine graft preservation and limb salvage rates. The management of infected prosthetic vascular grafts continues to be controversial. The purpose of this study was to review the surgical management of major extracavitary prosthetic vascular graft infections and to correlate the outcomes on the basis of bacteriology and grade. The change in patient population seen by vascular surgeons and the recent emergence of more virulent bacterial strains should influence surgical management. Bacteriology and severity of infection based on grade must play a greater role in the selection criteria for graft salvage. Despite advancement in the understanding of these interactions and the emergence of new management algorithms, we are continuing to operate without a uniform standard in managing this difficult and rapidly evolving clinical problem

Dilatonic global strings

We examine the field equations of a self-gravitating global string in low energy superstring gravity, allowing for an arbitrary coupling of the global string to the dilaton. Massive and massless dilatons are considered. For the massive dilaton the spacetime is similar to the recently discovered non-singular time-dependent Einstein self-gravitating global string, but the massless dilaton generically gives a singular spacetime, even allowing for time-dependence. We also demonstrate a time-dependent non-singular string/anti-string configuration, in which the string pair causes a compactification of two of the spatial dimensions, albeit on a very large scale.Comment: 18 pages RevTeX, 3 figures, references amende

High-energy gamma-ray emission from the inner jet of LS I+61 303: the hadronic contribution revisited

LS I+61 303 has been detected by the Cherenkov telescope MAGIC at very high energies, presenting a variable flux along the orbital motion with a maximum clearly separated from the periastron passage. In the light of the new observational constraints, we revisit the discussion of the production of high-energy gamma rays from particle interactions in the inner jet of this system. The hadronic contribution could represent a major fraction of the TeV emission detected from this source. The spectral energy distribution resulting from p-p interactions is recalculated. Opacity effects introduced by the photon fields of the primary star and the stellar decretion disk are shown to be essential in shaping the high-energy gamma-ray light curve at energies close to 200 GeV. We also present results of Monte Carlo simulations of the electromagnetic cascades developed very close to the periastron passage. We conclude that a hadronic microquasar model for the gamma-ray emission in LS I +61 303 can reproduce the main features of its observed high-energy gamma-ray flux.Comment: 6 pages. Sligth improvements made. Accepted version by Astrophysics and Space Scienc

Diquark condensation at strong coupling

The possibility of diquark condensation at sufficiently large baryon chemical potential and zero temperature is analyzed in QCD at strong coupling. In agreement with other strong coupling analysis, it is found that a first order phase transition separates a low density phase with chiral symmetry spontaneously broken from a high density phase where chiral symmetry is restored. In none of the phases diquark condensation takes place as an equilibrium state, but, for any value of the chemical potential, there is a metastable state characterized by a non-vanishing diquark condensate. The energy difference between this metastable state and the equilibrium state decreases with the chemical potential and is minimum in the high density phase. The results indicate that there is attraction in the quark-quark sector also at strong coupling, and that the attraction is more effective at high baryon density, but for infinite coupling it is not enough to produce diquark condensation. It is argued that the absence of diquark condensation is not a peculiarity of the strong coupling limit, but persists at sufficiently large finite couplings.Comment: 10 pages, 2 figures. An important discussion concerning the extension of the results to finite couplings adde

The extent and effectiveness of protected areas in the UK

The Convention on Biological Diversity (CBD), to which 196 countries including the UK are contracting parties, set out 20 Aichi Biodiversity Targets to be met by 2020. Elements of Aichi Target 11 call for at least 17% of terrestrial land and inland water to be protected and effectively managed by 2020. Each national government is requested to report progress against this goal in national reports submitted at intervals to the CBD, and these are used as the basis of reporting towards the 17% target. Figures reported for the UK’s protected area coverage are inclusive of a wide range of levels of designation, management and condition. Here, we examine the protection given to sites under UK legislation and designations as a case study. We find that although 28% of UK land is reported by the UK government to be protected, only 11.4% of land area falls within protected areas designated primarily for nature conservation. Condition monitoring indicates that at most 43–51% of protected areas in the UK are currently in favourable condition, which suggests as little as 4.9% of UK land area may be effectively protected for nature. However, estimates of protected area coverage vary greatly depending on the types of protected areas considered ‘effectively protected’ as measured by management category and site condition. Taking the UK as an example of a country that has reportedly met the target, we suggest that global progress may have been overestimated, and that future targets and indicators need to focus on the quality as well as quantity of protected areas

The effect of conservation interventions on the abundance of breeding waders within nature reserves in the United Kingdom

Breeding populations of many wading birds have declined globally, primarily caused by habitat degradation and loss. In the United Kingdom, population declines have been particularly notable on lowland wet grasslands. In response, some areas of lowland wet grassland have been restored and receive ongoing management to improve the breeding conditions of target species. Here, we assess the efficacy of management measures using a Bayesian framework and controlling for confounding factors. We focus on four wader species, Northern Lapwing (Vanellus vanellus), Eurasian Curlew (Numenius arquata), Common Snipe (Gallinago gallinago) and Common Redshank (Tringa totanus), that breed in numbers on wet grassland reserve sites in the UK. We collated annual site-specific climate variables, management information (e.g. the creation of wet features and predator control measures) and bird counts between 1994-2018. We found the effects of conservation actions varied between intervention types and species. For lapwing and redshank, excluding predators by predator-exclusion fencing, especially in combination with fox control, were generally associated with higher breeding counts. For all study species, sites with longer histories of management were associated with higher breeding numbers, with the effect of site age being particularly notable for management on former arable land. Our findings support the effectiveness of targeted conservation actions to achieve high numbers of breeding waders on lowland wet grassland reserves, and also highlight the value of consistent and reliable monitoring data

Precision Measurement of PArity Violation in Polarized Cold Neutron Capture on the Proton: the NPDGamma Experiment

The NPDGamma experiment at the Los Alamos Neutron Science Center (LANSCE) is dedicated to measure with high precision the parity violating asymmetry in the $\gamma$ emission after capture of spin polarized cold neutrons in para-hydrogen. The measurement will determine unambiguously the weak pion-nucleon-nucleon ($\pi NN$) coupling constant {\it f$^1_{\pi}$}Comment: Proceedings of the PANIC'05 Conference, Santa Fe, NM, USA, October 24-28, 2005, 3 pages, 2 figure

Evolving collective structures in the transitional nuclei W-162 and W-164

Excited states in the neutron-deficient nuclides W8874162 and W9074164 were investigated by using the γ-ray spectrometer Jurogam. A change in structure is apparent from the first rotational alignments in W162 and W164, whose rotationally aligned bands are interpreted as ν(h9/2)2 and ν(i13/2)2 configurations, respectively. The level schemes have been extended using recoil (-decay) correlations with the observation of excited collective structures. Configuration assignments have been made on the basis of comparisons of the deduced aligned angular momentum, as a function of rotational frequency, with the predictions of the cranked shell model

Gauge Theory and the Excision of Repulson Singularities

We study brane configurations that give rise to large-N gauge theories with eight supersymmetries and no hypermultiplets. These configurations include a variety of wrapped, fractional, and stretched branes or strings. The corresponding spacetime geometries which we study have a distinct kind of singularity known as a repulson. We find that this singularity is removed by a distinctive mechanism, leaving a smooth geometry with a core having an enhanced gauge symmetry. The spacetime geometry can be related to large-N Seiberg-Witten theory.Comment: 31 pages LaTeX, 2 figures (v3: references added