We study the mass spectra of excited baryons with the use of the lattice QCD simulations. We focus our attention on the problem of the level ordering between the positive-parity excited state N ′ (1440) (the Roper resonance) and the negative-parity excited state N * (1535). Nearly perfect parity projection is accomplished by combining the quark propagators with periodic and anti-periodic boundary conditions in the temporal direction. Then we extract the spectral functions from the lattice data by utilizing the maximum entropy method. We observe that the masses of the N ′ and N * states are close for wide range of the quark masses (M π = 0.61 − 1.22 GeV), which is in contrast to the phenomenological prediction of the quark models. The role of the Wilson doublers in the baryonic spectral functions is also studied.

Scattering lengths for two pseudoscalar meson systems, ππðI ¼ 2Þ, KKðI ¼ 1Þ and πKðI ¼ 3=2; 1=2Þ, are calculated from lattice QCD by using the finite size formula. We perform the calculation with N f ¼ 2 þ 1 gauge configurations generated on 32 3 × 64 lattice using the Iwasaki gauge action and a nonperturbatively OðaÞ-improved Wilson action at a −1 ¼ 2.19 GeV. The quark masses correspond to m π ¼ 0.17-0.71 GeV. For the πKðI ¼ 1=2Þ system, we use the variational method with the two operators, su and πK, to separate the contamination from the higher states. In order to obtain the scattering length at the physical quark mass, we fit our results at several quark masses with the formula of the Oðp 4 Þ chiral perturbation theory and that includes the effects of the discretization error from the Wilson fermion, Wilson chiral perturbation theory. We found that the mass dependence of our results near m π ¼ 0.17 GeV are described well by Wilson chiral perturbation theory but not by chiral perturbation theory. The scattering lengths at the physical point are given as a

A study of the finite-size effect is carried out for spectra of both ground-state and excited-state baryons in quenched lattice QCD using Wilson fermions. Our simulations are performed at β = 6/g 2 = 6.2 with three different spatial sizes, La ∼ 1.6, 2.2 and 3.2 fm. It is found that the physical lattice size larger than 3 fm is required for ∆ states in all spin-parity (J P = 1/2 ± , 3/2 ± ) channels and also negative-parity nucleon (N * ) state (J P = 1/2 − ) even in the rather heavy quark mass region (M π ∼ 1.0 GeV). We also find a peculiar behavior of the finite-size effect on the hyperfine mass splittings between the nucleon and the ∆ in both parity channels.

Cell transformation assays (CTAs) have long been proposed as in vitro methods for the identification of potential chemical carcinogens. Despite showing good correlation with rodent bioassay data, concerns over the subjective nature of using morphological criteria for identifying transformed cells and a lack of understanding of the mechanistic basis of the assays has limited their acceptance for regulatory purposes. However, recent drivers to find alternative carcinogenicity assessment methodologies, such as the Seventh Amendment to the EU Cosmetics Directive, have fuelled renewed interest in CTAs. Research is currently ongoing to improve the objectivity of the assays, reveal the underlying molecular changes leading to transformation and explore the use of novel cell types. The UK NC3Rs held an international workshop in November 2010 to review the current state of the art in this field and provide directions for future research. This paper outlines the key points highlighted at this meeting.

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Rapid evolution caused by human exploitation of wildlife is not usually addressed in studies of the impacts of such exploitation despite its direct relevance to population persistence. Japanese mamushi (Gloydius

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The transformation frequency of mouse BALB/3T3 cells was significantly enhanced after transfection with an activated ras oncogene (v‐Ha‐ras) followed by treatment with a tumor promoter, 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA), suggesting that the ras oncogene acted as an initiator in two‐stage carcinogenesis. A cell clone (Bhas42) containing the ras oncogene was isolated from the ras‐transfected BALB/3T3 cells. Bhas42 cells were flat and showed contact inhibition, but the addition of TPA to quiescent Bhas42 cultures resulted in a dramatic change of cell morphology to spindle shape, doubling of the cell population, and increased DNA synthesis.