Pattern avoidance classes and subpermutations

Pattern avoidance classes of permutations that cannot be expressed as unions of proper subclasses can be described as the set of subpermutations of a single bijection. In the case that this bijection is a permutation of the natural numbers a structure theorem is given. The structure theorem shows that the class is almost closed under direct sums or has a rational generating function.Comment: 18 pages, 4 figures (all in-line

Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial

Background: Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappointing but none has utilised IgG antibodies. Aims: To assess the therapeutic potential of dietary elimination based on the presence of IgG antibodies to food. Patients: A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies ( enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies. Methods: Primary outcome measures were change in IBS symptom severity and global rating scores. Non-colonic symptomatology, quality of life, and anxiety/depression were secondary outcomes. Intention to treat analysis was undertaken using a generalised linear model. Results: After 12 weeks, the true diet resulted in a 10% greater reduction in symptom score than the sham diet ( mean difference 39 (95% confidence intervals (CI) 5 - 72); p = 0.024) with this value increasing to 26% in fully compliant patients ( difference 98 ( 95% CI 52 - 144); p< 0.001). Global rating also significantly improved in the true diet group as a whole ( p = 0.048, NNT = 9) and even more in compliant patients ( p = 0.006, NNT = 2.5). All other outcomes showed trends favouring the true diet. Relaxing the diet led to a 24% greater deterioration in symptoms in those on the true diet ( difference 52 ( 95% CI 18 - 88); p = 0.003). Conclusion: Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research

AN ANALYSIS OF HOUSEHOLD CONSUMPTION OF RABBIT MEAT IN THE SOUTHERN UNITED STATES

Results from a random sample of 1421 households in the southern United States suggest that the most likely consumers of rabbit meat are men, non-college graduates, those with household incomes at or below $50,000, households with children, and Louisiana residents. The current market for rabbit meat is small. However, the meat is lower in fat, cholesterol, and calories, and higher in protein than beef, chicken, turkey, or pork, and these desirable nutritional attributes may spark future demand.Food Consumption/Nutrition/Food Safety,

A case study of MMO2's Madic: A framework for creating mobile internet systems

Mobile Internet applications on ubiquitous mobile networks allows real-time, anywhere, anytime connectivity to services. Due to its scalability and potential cost savings, mobile communication is being increasingly applied in the business and consumer communities to create innovative data and voice application, which run over the Internet infrastructure. This paper reports on a case study at an organisation that created an innovative approach to developing mobile applications developed by third party independent developers. A conceptual wireless reference model is presented that was used to define the various system components required to create effective mobile applications

Multiplicative renormalizability and quark propagator

The renormalized Dyson-Schwinger equation for the quark propagator is studied, in Landau gauge, in a novel truncation which preserves multiplicative renormalizability. The renormalization constants are formally eliminated from the integral equations, and the running coupling explicitly enters the kernels of the new equations. To construct a truncation which preserves multiplicative renormalizability, and reproduces the correct leading order perturbative behavior, non-trivial cancellations involving the full quark-gluon vertex are assumed in the quark self-energy loop. A model for the running coupling is introduced, with infrared fixed point in agreement with previous Dyson-Schwinger studies of the gauge sector, and with correct logarithmic tail. Dynamical chiral symmetry breaking is investigated, and the generated quark mass is of the order of the extension of the infrared plateau of the coupling, and about three times larger than in the Abelian approximation, which violates multiplicative renormalizability. The generated scale is of the right size for hadronic phenomenology, without requiring an infrared enhancement of the running coupling.Comment: 17 pages; minor corrections, comparison to lattice results added; accepted for publication in Phys. Rev.

Van der Waals interactions in the ground state of Mg(BH4)2 from density functional theory

In order to resolve an outstanding discrepancy between experiment and theory regarding the ground-state structure of Mg(BH4)2, we examine the importance of long-range dispersive interactions on the compound's thermodynamic stability. Careful treatment of the correlation effects within a recently developed nonlocal van der Waals density functional (vdW-DF) leads to a good agreement with experiment, favoring the {\alpha}-Mg(BH4)2 phase (P6122) and a closely related Mn(BH4)2-prototype phase (P3112) over a large set of polymorphs at low temperatures. Our study demonstrates the need to go beyond (semi)local density functional approximations for a reliable description of crystalline high-valent metal borohydrides.Comment: Phys. Rev. B, accepted, 7 pages, 4 figure

Generalized Inverse Participation Ratio as a Possible Measure of Localization for Interacting Systems

We test the usefulness of a generalized inverse participation ratio (GIPR) as a measure of Anderson localization. The GIPR differs from the usual inverse participation ratio in that it depends on the local density of states rather than on the single-electron wavefunctions. This makes it suitable for application to many-body systems. We benchmark the GIPR by performing a finite-size scaling analysis of a disordered, noninteracting, three-dimensional tight-binding lattice. We find values for the critical disorder and critical exponents that are in agreement with published values.Comment: 6 pages, 5 figures Accepted for publication in PR

Growth rates for subclasses of Av(321)

Pattern classes which avoid 321 and other patterns are shown to have the same growth rates as similar (but strictly larger) classes obtained by adding articulation points to any or all of the other patterns. The method of proof is to show that the elements of the latter classes can be represented as bounded merges of elements of the original class, and that the bounded merge construction does not change growth rates

Phase Structure of QED3 at Finite Temperature

Dynamical symmetry breaking in three-dimensional QED with N fermion flavours is considered at finite temperature, in the large $N$ approximation. Using an approximate treatment of the Schwinger-Dyson equation for the fermion self-energy, we find that chiral symmetry is restored above a certain critical temperature which depends itself on $N$. We find that the ratio of the zero-momentum zero-temperature fermion mass to the critical temperature has a large value compared with four-fermion theories, as had been suggested in a previous work with a momentum-independent self-energy. Evidence of a temperature- dependent critical $N$ is shown to appear in this approximation. The phase diagram for spontaneous mass generation in the theory is presented in $T-N$ space.Comment: 9 page