Subleading corrections to the Double Coset Ansatz preserve integrability

In this article we compute the anomalous dimensions for a class of operators, belonging to the SU(3) sector of the theory, that have a bare dimension of order N. For these operators the large N limit and the planar limit are distinct and summing only the planar diagrams will not capture the large N dynamics. Although the spectrum of anomalous dimensions has been computed for this class of operators, previous studies have neglected certain terms which were argued to be small. After dropping these terms diagonalizing the dilatation operator reduces to diagonalizing a set of decoupled oscillators. In this article we explicitly compute the terms which were neglected previously and show that diagonalizing the dilatation operator still reduces to diagonalizing a set of decoupled oscillators.Comment: 1 + 39 pages; v2: references adde

Higher Loop Nonplanar Anomalous Dimensions from Symmetry

In this article we study the action of the one loop dilatation operator on operators with a classical dimension of order N. These operators belong to the su(2) sector and are constructed using two complex fields Y and Z. For these operators non-planar diagrams contribute already at the leading order in N and the planar and large N limits are distinct. The action of the one loop and the two loop dilatation operator reduces to a set of decoupled oscillators and factorizes into an action on the Z fields and an action on the Y fields. Direct computation has shown that the action on the Y fields is the same at one and two loops. In this article, using the su(2) symmetry algebra as well as structural features of field theory, we give compelling evidence that the factor in the dilatation operator that acts on the Ys is given by the one loop expression, at any loop order.Comment: 1+40 page

142Nd/144Nd Inferences on the nature and origin of the source of high 3He/4He magmas

High-precision measurements of 142Nd/144Nd in picrites from the Baffin Bay region that contain the highest 3He/4He ratios yet measured in terrestrial mantle-derived rocks are indistinguishable from the value measured in the terrestrial standard and other modern mantle-derived rocks. The Baffin Island lavas are distinguished from other hotspot lavas by their unusually high 3He/4He and 182W/184W ratios, but their Sr, 142Nd, 143Nd, Hf, and Pb isotopic signatures overlap the values measured in North Atlantic MORB. These features imply either that the mantle source region of high 3He/4He magmas carries the lithophile isotopic signatures of incompatible element depletion, or that the He isotope signature of this source is decoupled from the lithophile isotope tracers in the magmas. The coupled 142Nd–143Nd data are consistent with the magma source acquiring the incompatible element depletion during, or shortly after, Earth formation if the bulk-Earth has a 142Nd/144Nd ratio more similar to the average measured for enstatite chondrites than modern terrestrial rocks. If Earth's initial 142Nd/144Nd was higher than the average of enstatite chondrites, the data are consistent with the traditional interpretation that the depleted-mantle reservoir was formed through the extraction of an incompatible-element-rich reservoir, such as continental crust, after the circa 4 Ga extinction of 146Sm. This explanation, however, fails to account for the high 3He/4He. The Nd isotopic composition of the picrites could reflect a dominant contribution from the incompatible element depleted source of North Atlantic MORB, overprinted by a small (10–20%) contribution from a mantle source with He concentrations at least ten times higher than the depleted mantle along with W isotopic compositions substantially higher than typical of mantle-derived rocks

Reconsidering the calculation and role of environmental footprints

Following the recent Copenhagen Climate Change conference, there has been discussion of the methods and underlying principles that inform climate change targets. Climate change targets following the Kyoto Protocol are broadly based on a production accounting principle (PAP). This approach focuses on emissions produced within given geographical boundaries. An alternative approach is a consumption accounting principle (CAP), where the focus is on emissions produced globally to meet consumption demand within the national (or regional) economy1. Increasingly popular environmental footprint measures, including ecological and carbon footprints, attempt to measure environmental impacts based on CAP methods. The perception that human consumption decisions lie at the heart of the climate change problem is the impetus driving pressure on policymakers for a more widespread use of CAP measures. At a global level of course, emissions accounted for under the production and consumption accounting principles would be equal. It is international trade that leads to differences in emissions under the two principles. This paper, the second in this special issue of the Fraser Commentary, examines how input-output accounting techniques may be applied to examine pollution generation under both of these accounting principles, focussing on waste and carbon generation in the Welsh economy as a case study. However, we take a different focus, arguing that the ‘domestic technology assumption’, taken as something of a mid-point in moving between production and consumption accounting in the first paper, may actually constitute a more useful focus for regional policymakers than full footprint analyses

Influence of zinc on distiller’s yeast:cellular accumulation of zinc and impact on spirit congeners

Accumulation of zinc by a whisky distilling yeast strain of Saccharomyces cerevisiae was studied during fermentation of malt wort and synthetic defined medium. Zinc uptake by yeast cells was very rapid in malt wort, as zinc (0.32 μg/mL) was completely removed from the fermentation medium within one hour. The type of fermentable carbohydrate had an impact on the kinetics of zinc accumulation, with maltose most effective at enhancing metal uptake at zinc concentrations above 3.2 μg/mL. Enriching yeast cells with zinc by “preconditioning” impacted on the production of flavour congeners in the distillates produced from fermented cultures. Such distillates were characterized by an altered flavour and aroma profile. In particular, the production of some higher alcohols increased when yeast cells were preconditioned with zinc. This phenomenon is yeast strain related. Industrial fermentation processes, including brewing and distilling, may benefit from optimization of zinc bioavailability in yeast cultures resulting in more efficient fermentations and improved product quality

Bio-inspired pulmonary surfactant-modified nanogels : a promising siRNA delivery system

Inhalation therapy with small interfering RNA (siRNA) is a promising approach in the treatment of pulmonary disorders. However, clinical translation is severely limited by the lack of suitable delivery platforms. In this study, we aim to address this limitation by designing a novel bioinspired hybrid nanoparticle with a core-shell nanoarchitecture, consisting of a siRNA-loaded dextran nanogel (siNG) core and a pulmonary surfactant (Curosurf (R)) outer shell. The decoration of siNGs with a surfactant shell enhances the colloidal stability and prevents siRNA release in the presence of competing polyanions, which are abundantly present in biofluids. Additionally, the impact of the surfactant shell on the biological efficacy of the siNGs is determined in lung cancer cells. The presence of the surfactants substantially reduces the cellular uptake of siNGs. Remarkably, the lowered intracellular dose does not impede the gene silencing effect, suggesting a crucial role of the pulmonary surfactant in the intracellular processing of the nanoparticles. In order to surmount the observed reduction in cellular dose, folate is incorporated as a targeting ligand in the pulmonary surfactant shell to incite receptor-mediated endocytosis. The latter substantially enhances both cellular uptake and gene silencing potential, achieving efficient knockdown at siRNA concentrations in the low nanomolar range. (C) 2015 Elsevier B.V. All rights reserved

Exploiting Synergy Between Ontologies and Recommender Systems

Recommender systems learn about user preferences over time, automatically finding things of similar interest. This reduces the burden of creating explicit queries. Recommender systems do, however, suffer from cold-start problems where no initial information is available early on upon which to base recommendations. Semantic knowledge structures, such as ontologies, can provide valuable domain knowledge and user information. However, acquiring such knowledge and keeping it up to date is not a trivial task and user interests are particularly difficult to acquire and maintain. This paper investigates the synergy between a web-based research paper recommender system and an ontology containing information automatically extracted from departmental databases available on the web. The ontology is used to address the recommender systems cold-start problem. The recommender system addresses the ontology's interest-acquisition problem. An empirical evaluation of this approach is conducted and the performance of the integrated systems measured