Automated image analysis to improve bead ingestion toxicity test counts in the protozoan Tetrahymena pyriformis

Prova de tipográfica (In Press).Aims: To improve bead ingestion counts in Tetrahymena pyriformis by automated image analysis as an alternative to direct-counts. Methods and Results: Fluorescent latex beads were added to T. pyriformis cultures for ingestion tests. The number of beads ingested by 25 cells was counted directly by epifluorescence microscopy and compared with similar data from image analysis. ANOVA indicated that counts were not significantly different (P < 0.05). The image analysis particularly provided advantages in terms of speed. Conclusions: The image analysis is superior to direct beads counting in T. pyriformis particularly in terms of speed of analysis. Significance and Impact of the Study: The image analysis method is very rapid and will allow many more toxicological analyses to be undertaken with less operator error

Modelling Deformations in Car Crash animation

In this paper, we present a prototype of a deformation engine to efficiently model and render the damaged structure of vehicles in crash scenarios. We introduce a novel system architecture to accelerate the computation, which is traditionally an extremely expensive task. We alter a rigid body simulator to predict trajectories of cars during a collision and formulate a correction procedure to estimate the deformations of the collapsed car structures within the contact area. Non-linear deformations are solved based on the principle of energy conservation. Large plastic deformations resulting from collisions are modelled as a weighted combination of deformation examples of beams which can be produced using classical mechanics

Description of superdeformed nuclei in the interacting boson model

The interacting boson model is extended to describe the spectroscopy of superdeformed bands. Microscopic structure of the model in the second minimum is discussed and superdeformed bosons are introduced as the new building blocks. Solutions of a quadrupole Hamiltonian are implemented through the $1/N$ expansion method. Effects of the quadrupole parameters on dynamic moment of inertia and electric quadrupole transition rates are discussed and the results are used in a description of superdeformed bands in the Hg-Pb and Gd-Dy regions.Comment: 18 pages revtex, 9 figures available upon reques

Plasma 1-carbon metabolites and academic achievement in 15-yr-old adolescents

Academic achievement in adolescents is correlated with 1-carbon metabolism (1-CM), as folate intake is positively related and total plasma homocysteine (tHcy) negatively related to academic success. Because another 1-CM nutrient, choline is essential for fetal neurocognitive development, we hypothesized that choline and betaine could also be positively related to academic achievement in adolescents. In a sample of 15-yr-old children (n = 324), we measured plasma concentrations of homocysteine, choline, and betaine and genotyped them for 2 polymorphisms with effects on 1-CM, methylenetetrahydrofolate reductase (MTHFR) 677C>T, rs1801133, and phosphatidylethanolamine N-methyltransferase (PEMT), rs12325817 (G>C). The sum of school grades in 17 major subjects was used as an outcome measure for academic achievement. Lifestyle and family socioeconomic status (SES) data were obtained from questionnaires. Plasma choline was significantly and positively associated with academic achievement independent of SES factors (paternal education and income, maternal education and income, smoking, school) and of folate intake (P = 0.009, R2 = 0.285). With the addition of the PEMT rs12325817 polymorphism, the association value was only marginally changed. Plasma betaine concentration, tHcy, and the MTHFR 677C>T polymorphism did not affect academic achievement in any tested model involving choline. Dietary intake of choline is marginal in many adolescents and may be a public health concern

Quantum-critical pairing with varying exponents

We analyse the onset temperature T_p for the pairing in cuprate superconductors at small doping, when tendency towards antiferromagnetism is strong. We consider the model of Moon and Sachdev (MS), which assumes that electron and hole pockets survive in a paramagnetic phase. Within this model, the pairing between fermions is mediated by a gauge boson, whose propagator remains massless in a paramagnet. We relate the MS model to a generic \gamma-model of quantum-critical pairing with the pairing kernel \lambda (\Omega) \propto 1/\Omega^{\gamma}. We show that, over some range of parameters, the MS model is equivalent to the \gamma-model with \gamma =1/3 (\lambda (\Omega) \propto \Omega^{-1/3}). We find, however, that the parameter range where this analogy works is bounded on both ends. At larger deviations from a magnetic phase, the MS model becomes equivalent to the \gamma-model with varying \gamma >1/3, whose value depends on the distance to a magnetic transition and approaches \gamma =1 deep in a paramagnetic phase. Very near the transition, the MS model becomes equivalent to the \gamma-model with varying \gamma <1/3. Right at the magnetic QCP, the MS model is equivalent to the \gamma-model with \gamma =0+ (\lambda (\Omega) \propto \log \Omega), which is the model for color superconductivity. Using this analogy, we verified the formula for T_c derived for color superconductivity.Comment: 10 pages, 8 figures, submitted to JLTP for a focused issue on Quantum Phase Transition

Geniculo-Cortical Projection Diversity Revealed within the Mouse Visual Thalamus

This is the final version of the article. It was first available from PLOS via http://dx.doi.org/10.1371/journal.pone.0144846All dLGN cell co-ordinates, V1 injection sites, dLGN boundary coordinates, experimental protocols and analysis scripts are available for download from figshare at https://figshare.com/s/36c6d937b1844eec80a1.The mouse dorsal lateral geniculate nucleus (dLGN) is an intermediary between retina and primary visual cortex (V1). Recent investigations are beginning to reveal regional complexity in mouse dLGN. Using local injections of retrograde tracers into V1 of adult and neonatal mice, we examined the developing organisation of geniculate projection columns: the population of dLGN-V1 projection neurons that converge in cortex. Serial sectioning of the dLGN enabled the distribution of labelled projection neurons to be reconstructed and collated within a common standardised space. This enabled us to determine: the organisation of cells within the dLGN-V1 projection columns; their internal organisation (topology); and their order relative to V1 (topography). Here, we report parameters of projection columns that are highly variable in young animals and refined in the adult, exhibiting profiles consistent with shell and core zones of the dLGN. Additionally, such profiles are disrupted in adult animals with reduced correlated spontaneous activity during development. Assessing the variability between groups with partial least squares regression suggests that 4?6 cryptic lamina may exist along the length of the projection column. Our findings further spotlight the diversity of the mouse dLGN?an increasingly important model system for understanding the pre-cortical organisation and processing of visual information. Furthermore, our approach of using standardised spaces and pooling information across many animals will enhance future functional studies of the dLGN.Funding was provided by a Wellcome Trust grant jointly awarded to IDT and SJE (083205, www.wellcome.ac.uk), and by MRC PhD Studentships awarded to MNL and ACH (http://www.mrc.ac.uk/)

Oxygen- and capacity-limited thermal tolerance: blurring ecology and physiology

No abstract available

Search for the glueball candidates f0(1500) and fJ(1710) in gamma gamma collisions

Data taken with the ALEPH detector at LEP1 have been used to search for gamma gamma production of the glueball candidates f0(1500) and fJ(1710) via their decay to pi+pi-. No signal is observed and upper limits to the product of gamma gamma width and pi+pi- branching ratio of the f0(1500) and the fJ(1710) have been measured to be Gamma_(gamma gamma -> f0(1500)). BR(f0(1500)->pi+pi-) < 0.31 keV and Gamma_(gamma gamma -> fJ(1710)). BR(fJ(1710)->pi+pi-) < 0.55 keV at 95% confidence level.Comment: 10 pages, 3 figure