Heavy meson chiral perturbation theory in finite volume

We present the first step towards the estimation of finite volume effects in heavy-light meson systems using heavy meson chiral perturbation theory. We demonstrate that these effects can be amplified in both light-quark and heavy-quark mass extrapolations (interpolations) in lattice calculations. As an explicit example, we perform a one-loop calculation for the neutral B meson mixing system and show that finite volume effects, which can be comparable with currently quoted errors, are not negligible in both quenched and partially quenched QCD.Comment: Talk presented at Lattice2004(heavy), Fermilab, June 21st-26th, 2004. Three pages, two figure

Forever young: Childhoods, fairy tales and philosophy

Fairy tales play a substantial role in the shaping of childhoods. Developed into stories and played out in picture books, films and tales, they are powerful instruments that influence conceptions and treatments of the child and childhoods. This article argues that traditional fairy tales and contemporary stories derived from them use complex means to mould the ways that children live and experience their childhoods. This argument is illustrated through representations of childhoods and children in a selection of stories and an analysis of the ways they act on and produce the child subjects and childhoods they convey. The selected stories are examined through different philosophical lenses, utilizing Foucault, Lyotard and Rousseau. By problematizing these selected stories, the article analyses what lies beneath the surface of the obvious meanings of the text and enticing pictures in stories, as published or performed. Finally, this article argues for a careful recognition of the complexities of stories used in early childhood settings and their powerful and multifaceted influences on children and childhoods

Protein contact order prediction from primary sequences

© 2008 Shi et al; licensee BioMed Central Ltd

What is the airspeed velocity of an unladen swallow? modeling numerical judgments of realistic stimuli

Research on processes of multiple-cue judgments usually uses artificial stimuli with predefined cue structures, such as artificial bugs with four binary features like back color, belly color, gland size, and spot shape. One reason for using artifical stimuli is that the cognitive models used in this area need known cues and cue values. This limitation makes it difficult to apply the models to research questions with complex naturalistic stimuli with unknown cue structure. In two studies, building on early categorization research, we demonstrate how cues and cue values of complex naturalistic stimuli can be extracted from pairwise similarity ratings with a multidimensional scaling analysis. These extracted cues can then be used in a state-of-the-art hierarchical Bayesian model of numerical judgments. In the first study, we show that predefined cue structures of artificial stimuli are well recovered by an MDS analysis of similarity judgments and that using these MDS-based attributes as cues in a cognitive model of judgment data from an existing experiment leads to the same inferences as when the original cue values were used. In the second study, we use the same procedure to replicate previous findings from multiple-cue judgment literature using complex naturalistic stimuli

Role of HDAC inhibition and environmental condition in altering phases of amphetamine self-administration

Doctor of PhilosophyPsychological SciencesMary E. CainGene-environment interactions play a significant role in drug abuse and addiction. Epigenetics (the study of how environmental stimuli alter gene expression) has gained attention in recent years as a significant contributor to many behavioral phenotypes of drug addiction. The current study sought to determine if differential rearing conditions can alter a specific epigenetic mechanism, histone deacetylase (HDAC), and how HDAC inhibition can affect drug-taking and drug-seeking behaviors differently among enriched, isolated, or standard-housed rats. Ninety male Sprague-Dawley rats were reared for 30 days in enriched (EC), isolated (IC), or standard (SC) conditions prior to amphetamine (0.03, 0.05, 0.1 mg/kg/infusion, i.v.) self-administration, extinction, or reinstatement sessions. Trichostatin A (TsA; 0.3 mg/kg, i.v.), an HDAC inhibitor, was injected 30 min prior to drug-taking or drug-seeking sessions. Results indicated that EC rats self-administered less amphetamine (0.03 mg/kg/infusion) than IC rats. No significant effects of TsA administration were found on general self-administration for any of the three amphetamine doses. While enrichment facilitated the extinction of active lever pressing, there was also a mild facilitation of extinction in IC-TsA rats compared to IC-vehicle counterparts. Lastly, TsA administration decreased cue-, but not drug-induced reinstatement, with IC-TsA rats exhibiting significantly attenuated cue-induced reinstatement compared to IC-vehicle rats. These findings suggest that differential rearing can alter HDAC mechanisms that can change drug-seeking behaviors, particularly in rats reared in isolated conditions. While TsA-induced HDAC inhibition may be less protective against general amphetamine self-administration, it may decrease drug-seeking tendencies during relapse that are induced by the reintroduction of contextual environmental cues heavily associated with drug reward

Region-specific emission factors for Brazil increase the estimate of nitrous oxide emissions from nitrogen fertiliser application by 21%

The use of synthetic nitrogen fertilisers is one of the most important land management practices proposed to improve crop and pasture productivity. The use of such fertilisers in excess can lead to greenhouse gas (GHG) emissions, linked to climate change, as well as ammonia (NH3) emissions, linked to eutrophication and soil acidification.. This context is especially important in Brazil, which is responsible for a significant share of the food produced in the world. To assess the impact of the use of nitrogen fertilisers, we conducted a structured review of Brazilian studies on the emission of nitrous oxide (N2O; 11 studies) and ammonia volatilisation (NH3; 13 studies) from nitrogen fertiliser application. The current emission factors (EF) suggested by the IPCC for N2O and NH3 (1 and 11%, respectively) are lower than the mean values we found in our review (1.12 and 19%, respectively). Our results showed that non-urea fertilisers (ammonium nitrate or ammonium sulphate) had a lower emission factor (EF) for N2O (1.07 and 0.60%, respectively) and NH3 (3.17 and 14%, respectively) in comparison with urea. The use of nitrification and urease inhibitors resulted in a reduction of the EFs of N2O (74% lower) and NH3 (43% lower) when compared with the Urea EF. Urea is the most common fertiliser used in Brazil, and the change for non-urea fertilisers or the use of inhibitors could lead to a reduction of 23% in the total N2O inventory. The use of the new region-specific EFs results in an increase of 21% in the final N2O emission inventory

Phase imaging with intermodulation atomic force microscopy

Intermodulation atomic force microscopy (IMAFM) is a dynamic mode of atomic force microscopy (AFM) with two-tone excitation. The oscillating AFM cantilever in close proximity to a surface experiences the nonlinear tip-sample force which mixes the drive tones and generates new frequency components in the cantilever response known as intermodulation products (IMPs). We present a procedure for extracting the phase at each IMP and demonstrate phase images made by recording this phase while scanning. Amplitude and phase images at intermodulation frequencies exhibit enhanced topographic and material contrast.Comment: 6 pages, 6 page