The Sensitivity in Methods of Measuring Conditioned Flavor Aversions and Conditioned Flavor Preferences

This project investigated a multiple measurement procedure to assess conditioned flavor aversions (CFA) and conditioned flavor preferences (CFP) in male albino rats. Volume consumed is currently the most common and often the sole method used. Most studies employ group designs, whereas this study used a single-subject design to compare behavior patters and responses between individual rats. Response measurements include: total licks, lick rate, lick patterns, volume (ml) consumed, volume (ml) per lick. Strong CFA showed consistent decreases in total licks, lick rate, total volume, ad volume per lick. CFP was evident, although not consistent, in total licks, lick rate, total volume (ml), and volume (ml) per lick. Volume per lick measurement in CFP revealed that three of the four rats drank more per lick on the posttest flavor day after training. This measure may be a good indicator of CFP. This study provides normative data for evaluating the effects of drugs on neurotransmitters that modulate CFA and CFP

Optimization of the visibility of graphene on poly-Si film by thin-film optics engineering

A multilayer optical system containing poly-Si film, SiO 2 film, and Si substrate (poly-Si substrate) has been designed to enhance the visibility of graphene in contact with poly-Si. Film thicknesses of poly-Si and SiO 2 have been optimized by parametric study of the integral contrast of single layer graphene using transfer matrix theory. The multilayer poly-Si substrate and the most commonly used 285 nm SiO 2 /Si substrate (SiO 2 substrate) have been fabricated. Graphene grown by chemical vapor deposition on Ni catalyst has been transferred to the substrates and the visibility of the graphene on the different substrates has been compared. The samples have been characterized by optical microscope, illuminated with light from halogen lamp, and/or filtered with a 600 nm narrow band optical filter. The contrast of graphene on poly-Si substrate has been increased to near 8.7 under 600 nm narrow band illumination from nearly invisible under ordinary illumination, while the contrast of graphene on SiO 2 remains almost the same. Raman spectroscopy has been used to verify the presence of the single layer graphene on the poly-Si substrate.</p

Aquatic and terrestrial invertebrate community responses to drying in chalk streams

Temporary streams are dynamic ecosystems that shift between wet and dry states and include the ‘winterbourne’ chalk streams of south England. Our understanding of temporary stream biodiversity is biased, with most research to date exploring aquatic invertebrate communities in benthic sediments during flowing phases. We surveyed the invertebrate communities of the Candover Brook chalk stream, comparing aquatic (benthic, hyporheic) and terrestrial communities in reaches with different flow permanence regimes. We used kick and Bou–Rouch sampling methods to collect aquatic invertebrates, and compared the terrestrial communities characterised by pitfall traps and ground searches and in different seasons. Although aquatic taxa richness was lower in temporary compared to perennial reaches, the total biodiversity of temporary stream channels was enhanced by contributions from both aquatic and terrestrial species, including several of conservation interest. We recommend that both aquatic and terrestrial communities should be considered in research and monitoring to characterise the biodiversity and ecological quality of temporary streams

A Mass Bound for Spherically Symmetric Black Hole Spacetimes

Requiring that the matter fields are subject to the dominant energy condition, we establish the lower bound $(4\pi)^{-1} \kappa {\cal A}$ for the total mass $M$ of a static, spherically symmetric black hole spacetime. (${\cal A}$ and $\kappa$ denote the area and the surface gravity of the horizon, respectively.) Together with the fact that the Komar integral provides a simple relation between $M - (4\pi)^{-1} \kappa A$ and the strong energy condition, this enables us to prove that the Schwarzschild metric represents the only static, spherically symmetric black hole solution of a selfgravitating matter model satisfying the dominant, but violating the strong energy condition for the timelike Killing field $K$ at every point, that is, $R(K,K) \leq 0$. Applying this result to scalar fields, we recover the fact that the only black hole configuration of the spherically symmetric Einstein-Higgs model with arbitrary non-negative potential is the Schwarzschild spacetime with constant Higgs field. In the presence of electromagnetic fields, we also derive a stronger bound for the total mass, involving the electromagnetic potentials and charges. Again, this estimate provides a simple tool to prove a ``no-hair'' theorem for matter fields violating the strong energy condition.Comment: 16 pages, LATEX, no figure

Uniqueness Theorem for Static Black Hole Solutions of sigma-models in Higher Dimensions

We prove the uniqueness theorem for self-gravitating non-linear sigma-models in higher dimensional spacetime. Applying the positive mass theorem we show that Schwarzschild-Tagherlini spacetime is the only maximally extended, static asymptotically flat solution with non-rotating regular event horizon with a constant mapping.Comment: 5 peges, Revtex, to be published in Class.Quantum Gra