Increased Birth Weight is Associated with Altered Gene Expression in Neonatal Foreskin

Elevated birth weight is linked to glucose intolerance and obesity health-related complications later in life. No studies have examined if infant birth weight is associated with gene expression markers of obesity and inflammation in a tissue that comes directly from the infant following birth. We evaluated the association between birth weight and gene expression on fetal programming of obesity. Foreskin samples were collected following circumcision, and gene expression analyzed comparing the 15% greatest birth weight infants (n = 7) v. the remainder of the cohort (n = 40). Multivariate linear regression models were fit to relate expression levels on differentially expressed genes to birth weight group with adjustment for variables selected from a list of maternal and infant characteristics. Glucose transporter type 4 (GLUT4), insulin receptor substrate 2 (IRS2), leptin receptor (LEPR), lipoprotein lipase (LPL), low-density lipoprotein receptor-related protein 1 (LRP1), matrix metalloproteinase 2 (MMP2), plasminogen activator inhibitor-1 (PAI-1) and transcription factor 7-like 2 (TCF7L2) were significantly upregulated and histone deacetylase 1 (HDAC1) and thioredoxin (TXN) downregulated in the larger birth weight neonates v. controls. Multivariate modeling revealed that the estimated adjusted birth weight group difference exceeded one standard deviation of the expression level for eight of the 10 genes. Between 25 and 50% of variation in expression level was explained by multivariate modeling for eight of the 10 genes. Gene expression related to glycemic control, appetite/energy balance, obesity and inflammation were altered in tissue from babies with elevated birth weight, and these genes may provide important information regarding fetal programming in macrosomic babies

The agroecology of malaria, maize, mosquitoes and dynamic landscape change in Ethiopia

PSAE Research Series No. 1

The Roles of Tidal Evolution and Evaporative Mass Loss in the Origin of CoRoT-7 b

CoRoT-7 b is the first confirmed rocky exoplanet, but, with an orbital semi-major axis of 0.0172 AU, its origins may be unlike any rocky planet in our solar system. In this study, we consider the roles of tidal evolution and evaporative mass loss in CoRoT-7 b's history, which together have modified the planet's mass and orbit. If CoRoT-7 b has always been a rocky body, evaporation may have driven off almost half its original mass, but the mass loss may depend sensitively on the extent of tidal decay of its orbit. As tides caused CoRoT-7 b's orbit to decay, they brought the planet closer to its host star, thereby enhancing the mass loss rate. Such a large mass loss also suggests the possibility that CoRoT-7 b began as a gas giant planet and had its original atmosphere completely evaporated. In this case, we find that CoRoT-7 b's original mass probably didn't exceed 200 Earth masses (about 2/3 of a Jupiter mass). Tides raised on the host star by the planet may have significantly reduced the orbital semi-major axis, perhaps causing the planet to migrate through mean-motion resonances with the other planet in the system, CoRoT-7 c. The coupling between tidal evolution and mass loss may be important not only for CoRoT-7 b but also for other close-in exoplanets, and future studies of mass loss and orbital evolution may provide insight into the origin and fate of close-in planets, both rocky and gaseous.Comment: Accepted for publication by MNRAS on 2010 May

Radio continuum observations of Class I protostellar disks in Taurus: constraining the greybody tail at centimetre wavelengths

We present deep 1.8 cm (16 GHz) radio continuum imaging of seven young stellar objects in the Taurus molecular cloud. These objects have previously been extensively studied in the sub-mm to NIR range and their SEDs modelled to provide reliable physical and geometrical parametres.We use this new data to constrain the properties of the long-wavelength tail of the greybody spectrum, which is expected to be dominated by emission from large dust grains in the protostellar disk. We find spectra consistent with the opacity indices expected for such a population, with an average opacity index of beta = 0.26+/-0.22 indicating grain growth within the disks. We use spectra fitted jointly to radio and sub-mm data to separate the contributions from thermal dust and radio emission at 1.8 cm and derive disk masses directly from the cm-wave dust contribution. We find that disk masses derived from these flux densities under assumptions consistent with the literature are systematically higher than those calculated from sub-mm data, and meet the criteria for giant planet formation in a number of cases.Comment: submitted MNRA