On the p,qp,q-binomial distribution and the Ising model

A completely new approach to the Ising model in 1 to 5 dimensions is developed. We employ $p,q$-binomial coefficients, a generalisation of the binomial coefficients, to describe the magnetisation distributions of the Ising model. For the complete graph this distribution corresponds exactly to the limit case $p=q$. We take our investigation to the simple $d$-dimensional lattices for $d=1,2,3,4,5$ and fit $p,q$-binomial distributions to our data, some of which are exact but most are sampled. For $d=1$ and $d=5$ the magnetisation distributions are remarkably well-fitted by $p,q$-binomial distributions. For $d=4$ we are only slightly less successful, while for $d=2,3$ we see some deviations (with exceptions!) between the $p,q$-binomial and the Ising distribution. We begin the paper by giving results on the behaviour of the $p,q$-distribution and its moment growth exponents given a certain parameterization of $p,q$. Since the moment exponents are known for the Ising model (or at least approximately for $d=3$) we can predict how $p,q$ should behave and compare this to our measured $p,q$. The results speak in favour of the $p,q$-binomial distribution's correctness regarding their general behaviour in comparison to the Ising model. The full extent to which they correctly model the Ising distribution is not settled though.Comment: 51 pages, 23 figures, submitted to PRB on Oct 23 200

A meta-analytic review of stand-alone interventions to improve body image

Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

Impact Factor: outdated artefact or stepping-stone to journal certification?

A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

HFE variants and the expression of iron-related proteins in breast cancer-associated lymphocytes and macrophages

Disponível em: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264664/The association of HFE (High Iron FE) major variants with breast cancer risk and behavior has been a matter of discussion for a long time. However, their impact on the expression of iron-related proteins in the breast cancer tissue has never been addressed. In the present study, hepcidin, ferroportin 1, transferrin receptor 1 (TfR1), and ferritin expressions, as well as tissue iron deposition were evaluated in a collection of samples from breast cancers patients and analyzed according to the patients’ HFE genotype. Within the group of patients with invasive carcinoma, those carrying the p.Cys282Tyr variant in heterozygosity presented a higher expression of hepcidin in lymphocytes and macrophages than wild-type or p.His63Asp carriers. An increased expression of TfR1 was also observed in all the cell types analyzed but only in p.Cys282Tyr/p.His63Asp compound heterozygous patients. A differential impact of the two HFE variants was further noticed with the observation of a significantly higher percentage of p.Cys282Tyr heterozygous patients presenting tissue iron deposition in comparison to p.His63Asp heterozygous. In the present cohort, no significant associations were found between HFE variants and classical clinicopathological markers of breast cancer behavior and prognosis. Although limited by a low sampling size, our results provide a new possible explanation for the previously reported impact of HFE major variants on breast cancer progression, i.e., not by influencing systemic iron homeostasis but rather by differentially modulating the local cellular expression of iron-related proteins and tissue iron deposition.OM is a recipient of the PhD grant SFRH/BD/2011/78184 from Fundação para a Ciência e Tecnologia (FCT). The authors also acknowledge financial support from ICBAS/AI&NSUMIB and by national funds through FCT and Ministério da Educação e Ciência (MEC) and when applicable co-funded by FEDER funds within the partnership agreement PT2020 related with the research unit number 4293.info:eu-repo/semantics/publishedVersio

Phenotypic Variation and Bistable Switching in Bacteria

Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.

Convergence of density expansions of correlation functions and the Ornstein-Zernike equation

We prove absolute convergence of the multi-body correlation functions as a power series in the density uniformly in their arguments. This is done by working in the context of the cluster expansion in the canonical ensemble and by expressing the correlation functions as the derivative of the logarithm of an appropriately extended partition function. In the thermodynamic limit, due to combinatorial cancellations, we show that the coeffi- cients of the above series are expressed by sums over some class of two-connected graphs. Furthermore, we prove the convergence of the density expansion of the “direct correlation function” which is based on a completely different approach and it is valid only for some inte- gral norm. Precisely, this integral norm is suitable to derive the Ornstein-Zernike equation. As a further outcome, we obtain a rigorous quantification of the error in the Percus-Yevick approximation

Genetic Organisation, Mobility and Predicted Functions of Genes on Integrated, Mobile Genetic Elements in Sequenced Strains of Clostridium difficile

Background: Clostridium difficile is the leading cause of hospital-associated diarrhoea in the US and Europe. Recently the incidence of C. difficile-associated disease has risen dramatically and concomitantly with the emergence of 'hypervirulent' strains associated with more severe disease and increased mortality. C. difficile contains numerous mobile genetic elements, resulting in the potential for a highly plastic genome. In the first sequenced strain, 630, there is one proven conjugative transposon (CTn), Tn5397, and six putative CTns (CTn1, CTn2 and CTn4-7), of which, CTn4 and CTn5 were capable of excision. In the second sequenced strain, R20291, two further CTns were described.Results: CTn1, CTn2 CTn4, CTn5 and CTn7 were shown to excise from the genome of strain 630 and transfer to strain CD37. A putative CTn from R20291, misleadingly termed a phage island previously, was shown to excise and to contain three putative mobilisable transposons, one of which was capable of excision. In silico probing of C. difficile genome sequences with recombinase gene fragments identified new putative conjugative and mobilisable transposons related to the elements in strains 630 and R20291. CTn5-like elements were described occupying different insertion sites in different strains, CTn1-like elements that have lost the ability to excise in some ribotype 027 strains were described and one strain was shown to contain CTn5-like and CTn7-like elements arranged in tandem. Additionally, using bioinformatics, we updated previous gene annotations and predicted novel functions for the accessory gene products on these new elements.Conclusions: The genomes of the C. difficile strains examined contain highly related CTns suggesting recent horizontal gene transfer. Several elements were capable of excision and conjugative transfer. The presence of antibiotic resistance genes and genes predicted to promote adaptation to the intestinal environment suggests that CTns play a role in the interaction of C. difficile with its human host

Interface localization near criticality

The theory of interface localization in near-critical planar systems at phase coexistence is formulated from first principles. We show that mutual delocalization of two interfaces, amounting to interfacial wetting, occurs when the bulk correlation length crit- ical exponent \u3bd is larger than or equal to 1. Interaction with a boundary or defect line involves an additional scale and a dependence of the localization strength on the distance from criticality. The implications are particularly rich in the boundary case, where de- localization proceeds through different renormalization patterns sharing the feature that the boundary field becomes irrelevant in the delocalized regime. The boundary delocal- ization (wetting) transition is shown to be continuous, with surface specific heat and layer thickness exponents which can take values that we determine