Chess endgames: 6-man data and strategy

While Nalimov’s endgame tables for Western Chess are the most used today, their Depth-to-Mate metric is not the most efficient or effective in use. The authors have developed and used new programs to create tables to alternative metrics and recommend better strategies for endgame play

Multibeam Maser Survey of methanol and excited OH in the Magellanic clouds: new detections and maser abundance estimates

‘The definitive version is available at www.blackwell-synergy.com.’ Copyright Blackwell Publishing DOI: 10.1111/j.1365-2966.2008.12888.xPeer reviewe

A field and laboratory evaluation of a commercial ELISA for the detection of Giardia coproantigens in humans and dogs

A capture enzyme linked immunosorbent assay (ELISA®) was evaluated for its ability to detect Giardia coproantigens in the faeces of humans and dogs in the Perth metropolitan area and Aboriginal communities in Fitzroy Crossing, Western Australia. Using zinc sulphate flotation and light microscopy, Giardia cysts and/or trophozoites were observed in 8 of 57 (14%) human stool samples from Perth and 21 of 55 (38%) stool samples from Fitzroy Crossing, after 2 separate examinations. Analysis of diagnostic sensitivity using the ELISA revealed that coproantigens were detected in all 29 human samples (100%) in which Giardia cysts and/or trophozoites were also present. Coproantigens were detected in one further sample from Perth and in 3 samples from Fitzroy Crossing in which no Giardia cyst or trophozoite was observed. The specificity of the test, as defined using Fitzroy Crossing samples free from Giardia, was 91%. The assay did not crossr-eact with Giardia-free stool samples containing Hymenolepis nana, Entamoeba coli, E. hartmanni, Chilomastix mesnili or Ancylostoma duodenale. Giardia cysts and/or trophozoites were also observed in 11 of 32 dog faecal samples (34%) in Perth and 11 of 29 dog samples (38%) in Fitzroy Crossing, after one zinc sulphate examination. The sensitivity of the ELISA for dogs was 64% and 55% for Perth and Fitzroy Crossing specimens respectively. The specificity was 95% when Fitzroy Crossing samples were used. Other parasites observed in Giardia-free faecal samples from dogs which did not produce a positive reaction with the kit were Ancylostoma caninum, Sarcocystis sp. and Isospora sp. The assay was tested under field conditions, in Fitzroy Crossing, where the results were read visually and were shown to correlate well with results obtained using spectrophotometry. Giardia coproantigens present in human stools remained detectable by the ELISA even after storage untreated at 25 °C for 8

Understanding the Observed Evolution of the Galaxy Luminosity Function from z=6-10 in the Context of Hierarchical Structure Formation

Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z~6-10 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF)--which also declines sharply over this redshift range--and the galaxy-formation physics that maps halo mass to galaxy luminosity. We consider the strong observed evolution in the LF from z~6-10 in this context and determine whether it can be explained solely by the behavior of the HMF. From z~6-8, we find a residual change in the physics of galaxy formation corresponding to a ~0.5 dex increase in the average luminosity of a halo of fixed mass. On the other hand, our analysis of recent LF measurements at z~10 shows that the paucity of detected galaxies is consistent with almost no change in the average luminosity at fixed halo mass from z~8. The LF slope also constrains the variation about this mean such that the luminosity of galaxies hosted by halos of the same mass are all within about an order-of-magnitude of each other. We show that these results are well-described by a simple model of galaxy formation in which cold-flow accretion is balanced by star formation and momentum-driven outflows. If galaxy formation proceeds in halos with masses down to 10^8 Msun, then such a model predicts that LBGs at z~10 should be able to maintain an ionized intergalactic medium as long as the ratio of the clumping factor to the ionizing escape fraction is C/f_esc < 10.Comment: 15 pages, 2 figures; results unchanged; accepted by JCA

Non-adiabatic corrections to elastic scattering of halo nuclei

We derive the formalism for the leading order corrections to the adiabatic approximation to the scattering of composite projectiles. Assuming a two-body projectile of core plus loosely-bound valence particle and a model (the core recoil model) in which the interaction of the valence particle and the target can be neglected, we derive the non-adiabatic correction terms both exactly, using a partial wave analysis, and using the eikonal approximation. Along with the expected energy dependence of the corrections, there is also a strong dependence on the valence-to-core mass ratio and on the strength of the imaginary potential for the core-target interaction, which relates to absorption of the core in its scattering by the target. The strength and diffuseness of the core-target potential also determine the size of the corrections. The first order non-adiabatic corrections were found to be smaller than qualitative estimates would expect. The large absorption associated with the core-target interaction in such halo nuclei as Be11 kills off most of the non-adiabatic corrections. We give an improved estimate for the range of validity of the adiabatic approximation when the valence-target interaction is neglected, which includes the effect of core absorption. Some consideration was given to the validity of the eikonal approximation in our calculations.Comment: 14 pages with 10 figures, REVTeX4, AMS-LaTeX v2.13, submitted to Phys. Rev.

Analytical approach to viscous fingering in a cylindrical Hele-Shaw cell

We report analytical results for the development of the viscous fingering instability in a cylindrical Hele-Shaw cell of radius a and thickness b. We derive a generalized version of Darcy's law in such cylindrical background, and find it recovers the usual Darcy's law for flow in flat, rectangular cells, with corrections of higher order in b/a. We focus our interest on the influence of cell's radius of curvature on the instability characteristics. Linear and slightly nonlinear flow regimes are studied through a mode-coupling analysis. Our analytical results reveal that linear growth rates and finger competition are inhibited for increasingly larger radius of curvature. The absence of tip-splitting events in cylindrical cells is also discussed.Comment: 14 pages, 3 ps figures, Revte

Southward expansion: The myth of the West in the promotion of Florida, 1876–1900

This article examines the ways in which promoters and developers of Florida, in the decades after Reconstruction, engaged with a popular myth of the West as a means of recasting and selling their state to prospective settlers in the North and Midwest. The myth envisaged a cherished region to the west where worthy Americans could migrate and achieve social and economic independence away from the crowded confines of the East, or Europe. According to state immigration agents, land-promoters and other booster writers, Florida, although a Southern ex-Confederate state, offered precisely these 'western' opportunities for those hard-working Northerners seeking land and an opening for agrarian prosperity. However, the myth, which posited that, in the west, an individual's labour and thrift were rewarded with social and economic improvement, meshed awkwardly with the contemporary emergence of Florida as a popular winter destination for wealthy tourists and invalids seeking leisure and healthfulness away from the North. Yet it also reflected and reinforced promotional notions of racial improvement which would occur with an influx of enterprising Anglo-Americans, who would effectively displace the state's large African American population. In Florida, the myth of the West supported the linked post-Reconstruction processes of state development and racial subjugation

Uncorrelated scattering approximation revisited

The formalism to describe the scattering of a weakly bound projectile nucleus by a heavy target is investigated, using the Uncorrelated Scattering Approximation. The main assumption involved is to neglect the correlation between the fragments of the projectile in the region where the interaction with the target is important. It is shown that the angular momentum of each fragment with respect to the target is conserved. Moreover, when suitable approximations are assumed, the kinetic energy of each fragment is also shown to be conserved. The S-matrix for the scattering of the composite system can be written as a combination of terms, each one being proportional to the product of the S-matrices of the fragments.Comment: 27 pages, 6 figures, submitted to Nucl. Phys. A (v2: minor misprints and grammatical errors corrected

Metabolic origins of spatial organization in the tumor microenvironment.

The genetic and phenotypic diversity of cells within tumors is a major obstacle for cancer treatment. Because of the stochastic nature of genetic alterations, this intratumoral heterogeneity is often viewed as chaotic. Here we show that the altered metabolism of cancer cells creates predictable gradients of extracellular metabolites that orchestrate the phenotypic diversity of cells in the tumor microenvironment. Combining experiments and mathematical modeling, we show that metabolites consumed and secreted within the tumor microenvironment induce tumor-associated macrophages (TAMs) to differentiate into distinct subpopulations according to local levels of ischemia and their position relative to the vasculature. TAMs integrate levels of hypoxia and lactate into progressive activation of MAPK signaling that induce predictable spatial patterns of gene expression, such as stripes of macrophages expressing arginase 1 (ARG1) and mannose receptor, C type 1 (MRC1). These phenotypic changes are functionally relevant as ischemic macrophages triggered tube-like morphogenesis in neighboring endothelial cells that could restore blood perfusion in nutrient-deprived regions where angiogenic resources are most needed. We propose that gradients of extracellular metabolites act as tumor morphogens that impose order within the microenvironment, much like signaling molecules convey positional information to organize embryonic tissues. Unearthing embryology-like processes in tumors may allow us to control organ-like tumor features such as tissue repair and revascularization and treat intratumoral heterogeneity

Feeling good about being hungry: food-related thoughts in eating disorder

Objectives: This study explores the relationships to food and hunger in women living with anorexic type eating difficulties and asks how imagery-based elaborations of food and eating thoughts are involved in their eating restraint, and recovery. Design: The qualitative idiographic approach of Interpretative Phenomenological Analysis (IPA) was used. Four in-depth semi-structured interviews were conducted with women self-selected as having experienced anorexia or anorexic like behaviour. Methods: The data was analysed using IPA and an audit of the analysis was conducted to ensure that the process followed had been systematic and rigorous and appropriately considered reflexivity. Results: Hunger was perceived positively by participants as confirmation that they were achieving their goal of losing weight, or avoiding weight gain. Hunger conferred a sense of being in control for the participants. Intrusive thoughts about food were reported as being quickly followed by elaborative mental imagery of the positive aspects of weight loss, and the negative consequences of eating. Imagery appeared to serve to maintain anorexic behaviours rather than to motivate food seeking. However, negative imagery of the consequences of anorexia were also described as supporting recovery. Conclusions: The finding that physiological sensations of hunger were experienced as positive confirmation of maintaining control has potentially important clinical and theoretical implications. It suggests further attention needs to be focused upon how changes in cognitive elaboration, involving mental imagery, are components of the psychological changes in the development of, maintenance of, and recovery from, anorexia