Percolation with long-range correlated disorder

Long-range power-law correlated percolation is investigated using Monte Carlo simulations. We obtain several static and dynamic critical exponents as function of the Hurst exponent $H$ which characterizes the degree of spatial correlation among the occupation of sites. In particular, we study the fractal dimension of the largest cluster and the scaling behavior of the second moment of the cluster size distribution, as well as the complete and accessible perimeters of the largest cluster. Concerning the inner structure and transport properties of the largest cluster, we analyze its shortest path, backbone, red sites, and conductivity. Finally, bridge site growth is also considered. We propose expressions for the functional dependence of the critical exponents on $H$

Predatory short sales and bailouts

This paper extends the literature on predatory short selling and bailouts through a joint analysis of the two. We consider a model with informed short sales, as well as uninformed predatory short sales, which can trigger the inefficient liquidation of a firm. We obtain several novel results: A government commitment to bail out insolvent firms with positive probability can increase welfare because it selectively deters predatory short selling without hampering desirable informed short sales. Contrasting a common view, bailouts can be optimal ex ante but undesirable ex post. Furthermore, bailouts in our model are a better policy tool than short selling restrictions. Welfare gains from the bailout policy are unevenly distributed: shareholders gain while taxpayers lose. Bailout taxes allow ex-ante Pareto improvements

Intake Levels of Fish in the UK Paediatric Population

The United Kingdom (UK) is an island and its culture, including diet, is heavily influenced by the maritime resources. Dietary guidance in the UK recommends intake of fish, which provides important nutrients, such as long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA). This study was designed to describe the fish intake habits of UK children using a nationally representative sample. Dietary and socio-demographic data of children 2–18 (N = 2096) in the National Diet and Nutrition Survey Rolling Program (NDNS) Years 1–4 (2008–2012) were extracted. Average nutrient and food intakes were estimated. Logistic regression models were used to predict the meeting of fish intake recommendations, controlling for age, sex, income, total energy intake, and survey year. All analyses were conducted using survey routines and dietary survey weights. In this nationally representative study, 4.7% of children met the fish and 4.5% the oily fish intake recommendations; only 1.3% of the population met both recommendations. Fish intake levels did not significantly change with children’s increasing age. Higher vegetable but lower meat consumption predicted meeting the fish intake recommendations, indicating that children eating fish have better diet quality than non-consumers. Further research is needed to explore how intake behaviours can be changed to improve children’s diet quality.N.R.V.J. and P.M. were supported by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The funders had no role in the design or conduct of the study or the writing of the manuscript. This research received no specific grant from any funding agency, commercial or not-for-profit sectors

Interaction of Streptavidin-Based Peptide-MHC Oligomers (Tetramers) with Cell-Surface T Cell Receptors

he binding of oligomeric peptide–MHC (pMHC) complexes to cell surface TCR can be considered to approximate TCR–pMHC interactions at cell-cell interfaces. In this study, we analyzed the equilibrium binding of streptavidin-based pMHC oligomers (tetramers) and their dissociation kinetics from CD8[superscript pos] T cells from 2C-TCR transgenic mice and from T cell hybridomas that expressed the 2C TCR or a high-affinity mutant (m33) of this TCR. Our results show that the tetramers did not come close to saturating cell-surface TCR (binding only 10–30% of cell-surface receptors), as is generally assumed in deriving affinity values (K[subscript D]), in part because of dissociative losses from tetramer-stained cells. Guided by a kinetic model, the oligomer dissociation rate and equilibrium constants were seen to depend not only on monovalent association and dissociation rates (k[subscript off] and k[subscript on]), but also on a multivalent association rate (μ) and TCR cell-surface density. Our results suggest that dissociation rates could account for the recently described surprisingly high frequency of tetramer-negative, functionally competent T cells in some T cell responses.National Institutes of Health (U.S.) (Grant P01 CA097296)National Institutes of Health (U.S.) (Grant R01 GM55767)National Institutes of Health (U.S.) (Grant PO1-AI071195)National Institutes of Health (U.S.). Pioneer Awar

Spider family Caponiidae

12 p. : ill. ; 26 cm. "August 28, 2009." Includes bibliographical references (p. 12).A new genus and species, Iraponia scutata, are established for the first members of the Caponiidae to be found in Iran. Males of this new genus, the second known from Asia, are unique in the family in having an extensive ventral abdominal scutum, and in having lost the posterior median pair of spinnerets. These caponiids have six eyes, a character shared only with some members of the New World genus Caponina.Published by the American Museum of Natural History, New york, NY

Bodies, technologies and action possibilities: when is an affordance?

Borrowed from ecological psychology, the concept of affordances is often said to offer the social study of technology a means of re-framing the question of what is, and what is not, ‘social’ about technological artefacts. The concept, many argue, enables us to chart a safe course between the perils of technological determinism and social constructivism. This article questions the sociological adequacy of the concept as conventionally deployed. Drawing on ethnographic work on the ways technological artefacts engage, and are engaged by, disabled bodies, we propose that the ‘affordances’ of technological objects are not reducible to their material constitution but are inextricably bound up with specific, historically situated modes of engagement and ways of life