Habitability of known exoplanetary systems based on measured stellar properties

At present, because of observational selection effects, we know of no exoplanetary systems with any planetary masses close to that of the Earth. We have therefore used computer models to see whether such planets could be dynamically stable in the presence of the more massive planets known to be present, and in particular whether planets with roughly an Earth mass could remain confined to the classical habitable zone (HZ) for long enough for life to have emerged. Measured stellar properties have been used to determine for each system the present location of the HZ. We have also determined the critical distances from the orbit of each giant planet within which an Earth-mass planet would suffer large orbital changes. We then evaluated the present habitability of each and every exoplanetary system by examining the penetration of these critical distances into the HZ. The critical distances can be obtained by extensive computer modelling of an exoplanetary system. This is far too time consuming to apply to all of the 150 or so systems already known, and to keep up with the latest discoveries. Therefore, in earlier work we studied a few systems in great detail, and developed a speedier means of obtaining the critical distances. We summarize this comparatively quick method here. We can then evaluate comparatively quickly the present habitability of each exoplanetary system by examining the penetration of the critical distance(s) into the HZ. The results are encouraging for astrobiology.Comment: Accepted for publication by The Astrophysical Journal. A few revisions have been made following suggestions by the refere

Size-tuneable nanometric MRI contrast agents for the imaging of molecular weight dependent transport processes

Purpose: To evaluate size-tuneable nanomeric glycol-chitosan-DTPA-Gd conjugates as MRI contrast agents for the imaging of molecular weight (MW) dependent transport processes. Material & Methods: Glycol chitosans (GC) – DTPA conjugates of precisely controlled MWs were synthesised and evaluated in mice against Gd-DTPA using times series of high-resolution MRI images of trunk, head, and xenograft flank tumours. All animal studies were approved by the local ethics committee and the UK authorities. Results: GC-DTPA modification ratio was one DTPA per 3.9 – 5.13 of GC monomers. GC-DTAPGd provided overall superior contrast compared to Gd-DTPA with the duration of the enhancement depending on MW (≥ 1h for 40kD). Kidneys showed early enhancement also in the renal pelvis suggesting renal elimination. Imaging of the head with GC-DTPA-Gd allowed detailed anatomical identification of specific blood vessels in particular with the high MW agent. Sequential high-resolution isotropic imaging of established A431 xenograft flank tumours with DTPA-Gd and GC-DTPA-Gd demonstrated that the initial delivery of the contrast agents was well correlated with blood supply. Subsequent tissue transport was primarily by diffusion and was limited by molecular weight. The data also highlight the role of heterogeneity in CA distribution that was again more prominent for the high MW agent. Conclusion: GC-DTPA-Gd with identical physical chemical properties but precisely controlled MW allow isotropic high-resolution three-dimensional imaging of molecular weight dependent transport processes which could potentially lead to clinical biomarkers for molecular weight dependent drug transport and support selection of suitable tumour models for pre-clinical development

Preparando estudantes da Pós-Graduação para a indústria e aprendizado para a vida: uma abordagem baseada em projeto

Este estudo de caso baseia-se em projetos que têm uma dimensão de mundo real, em que os alunos estão mais propensos a adquirir as competências e habilidades que a indústria exige. Informações de base são apresenta- das, relacionando vínculos entre a academia, a indústria e o papel dos projetos dos estudantes. Os dados são provenien- tes de programas de computação em nível de mestrado, da Universidade de Sunderland, e dos projetos desenvolvidos por cada um dos estudantes. Uma abordagem específica permitiu que centenas de projetos bem sucedidos, realiza- dos anualmente com o setor da indústria, fossem descritos juntamente com a avaliação de sua eficácia em dar aos alunos uma formação de competência para a vida

Organizational Assessment and Development Guide for Regional Associations

This publication was originally a product of The Regional Initiative, a 1992-1995special project cosponsored by the Council on Foundations and twenty-four of the nation's regional associations of grantmakers (RAGs). The purpose of the Initiative was to enhance the capacity of regional associations to meet their members' needs, by building both management and program effectiveness. The Initiative's long-term goal was to strengthen regional associations as agents of organized philanthropy in American life

Oxidation Reduction Potential of Developing Plaque, Periodontal Pockets and Gingival Sulci

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141573/1/jper0630.pd