3,132 research outputs found
Solvable Critical Dense Polymers on the Cylinder
A lattice model of critical dense polymers is solved exactly on a cylinder
with finite circumference. The model is the first member LM(1,2) of the
Yang-Baxter integrable series of logarithmic minimal models. The cylinder
topology allows for non-contractible loops with fugacity alpha that wind around
the cylinder or for an arbitrary number ell of defects that propagate along the
full length of the cylinder. Using an enlarged periodic Temperley-Lieb algebra,
we set up commuting transfer matrices acting on states whose links are
considered distinct with respect to connectivity around the front or back of
the cylinder. These transfer matrices satisfy a functional equation in the form
of an inversion identity. For even N, this involves a non-diagonalizable braid
operator J and an involution R=-(J^3-12J)/16=(-1)^{F} with eigenvalues
R=(-1)^{ell/2}. The number of defects ell separates the theory into sectors.
For the case of loop fugacity alpha=2, the inversion identity is solved exactly
for the eigenvalues in finite geometry. The eigenvalues are classified by the
physical combinatorics of the patterns of zeros in the complex
spectral-parameter plane yielding selection rules. The finite-size corrections
are obtained from Euler-Maclaurin formulas. In the scaling limit, we obtain the
conformal partition functions and confirm the central charge c=-2 and conformal
weights Delta_t=(t^2-1)/8. Here t=ell/2 and t=2r-s in the ell even sectors with
Kac labels r=1,2,3,...; s=1,2 while t is half-integer in the ell odd sectors.
Strikingly, the ell/2 odd sectors exhibit a W-extended symmetry but the ell/2
even sectors do not. Moreover, the naive trace summing over all ell even
sectors does not yield a modular invariant.Comment: 44 pages, v3: minor correction
Why political context is key in determining the parties interest groups choose to collaborate with
When interest groups choose to collaborate with political parties what determines the type of party they opt to work with? Anne Rasmussen and Simon Otjes write that the two key elements shaping this decision are typically the ideological similarities between the interest group and the party, together with how powerful the party is in terms of its role in government. Outlining a comparison of more than 750 Danish and Dutch interest groups, they note that the extent to which these two factors affect collaboration between interest groups and parties is dependent on the characteristics of political systems
No longer going steady, but playing the field: trade unions and the decline of social democracy
Parties on the centre-left often enjoy a special relationship with trade unions, but recent electoral losses for social democratic parties may limit the ability of unions to influence public policy. Simon Otjes and Anne Rasmussen examine how trade union-party relationships in the Netherlands might be affected by these developments. They argue that the losses suffered by the Social Democrats in the 2017 Dutch elections are unlikely to fundamentally weaken the role of Dutch trade unions in policy-making. Unions enjoy a direct connection to policy-making independent of government composition, and they hold ties to parties across the political spectrum due to the specific trade union traditions present in the country
Genome Sequence of Talaromyces atroroseus, Which Produces Red Colorants for the Food Industry
Talaromyces atroroseus is a known producer of Monascus colorants suitable for the food industry. Furthermore, genetic tools have been established that facilitate elucidation and engineering of its biosynthetic pathways. Here, we report the draft genome of a potential fungal cell factory, T. atroroseus IBT 11181 (CBS 123796)
Integrated modelling for assessing the risk of groundwater contaminants to human health and surface water ecosystems
The practical implementation of the European Water Framework Directive has resulted in an increased focus on the groundwater-surface water interaction zone. A gap exists with respect to preliminary assessment methodologies that are capable of evaluating and prioritising point sources of contamination. In particular, adaptive management tools designed to work with sparse data sets from preliminary site assessments are needed which can explicitly link contaminant point sources with groundwater, surface water and ecological impacts. Here, a novel integrated modelling approach was employed for evaluating the impact of a TCE groundwater plume, located in an area with protected drinking water interests, to human health and surface water ecosystems. This is accomplished by coupling the system dynamicsbased decision support system CARO-Plus to the aquatic ecosystem model AQUATOX via an analytical volatilisation model for the stream. The model is tested on a Danish case study involving a 750 m long TCE groundwater plume discharging into a stream. The initial modelling results indicate that TCE contaminant plumes with μgL-1 concentrations entering surface water systems do not pose a significant risk to either human or ecological receptors
Adolescent bullying and sleep difficulties
This study evaluated whether adolescents who report having been bullied, being bullies, or report both being a bully and being bullied experience more sleep difficulties than children uninvolved in bullying. The study drew upon cognitive theories of insomnia, investigating whether the extent to which young people report worrying about bullying can moderate associations between victimization and sleep difficulties. Participants were 5420 adolescents who completed a self-report questionnaire. Pure Victims (OR = 1.72: 95% CI [1.07 – 2.75]), Pure Bullies (OR = 1.80: 95% CI [1.16 – 2.81]), and Bully-Victims (OR = 2.90: 95% CI [1.17 – 4.92]) were all more likely to experience sleep difficulties when compared to uninvolved young people. The extent to which young people reported worrying about being bullied did not moderate the links between victimization and sleep difficulties. In this way, bullying is clearly related to sleep difficulties among adolescents but the conceptual reach of the cognitive model of insomnia in this domain is questioned
Metagenomic analysis of rapid gravity sand filter microbial communities suggests novel physiology of Nitrospira spp
Rapid gravity sand filtration is a drinking water production technology widely used around the world. Microbially catalyzed processes dominate the oxidative transformation of ammonia, reduced manganese and iron, methane and hydrogen sulfide, which may all be present at millimolar concentrations when groundwater is the source water. In this study, six metagenomes from various locations within a groundwater-fed rapid sand filter (RSF) were analyzed. The community gene catalog contained most genes of the nitrogen cycle, with particular abundance in genes of the nitrification pathway. Genes involved in different carbon fixation pathways were also abundant, with the reverse tricarboxylic acid cycle pathway most abundant, consistent with an observed Nitrospira dominance. From the metagenomic data set, 14 near-complete genomes were reconstructed and functionally characterized. On the basis of their genetic content, a metabolic and geochemical model was proposed. The organisms represented by draft genomes had the capability to oxidize ammonium, nitrite, hydrogen sulfide, methane, potentially iron and manganese as well as to assimilate organic compounds. A composite Nitrospira genome was recovered, and amo-containing Nitrospira genome contigs were identified. This finding, together with the high Nitrospira abundance, and the abundance of atypical amo and hao genes, suggests the potential for complete ammonium oxidation by Nitrospira, and a major role of Nitrospira in the investigated RSFs and potentially other nitrifying environments
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