Stromal Gli2 activity coordinates a niche signaling program for mammary epithelial stem cells

The stem cell niche is a complex local signaling microenvironment that sustains stem cell activity during organ maintenance and regeneration. The mammary gland niche must support its associated stem cells while also responding to systemic hormonal regulation that triggers pubertal changes. We find that Gli2, the major Hedgehog pathway transcriptional effector, acts within mouse mammary stromal cells to direct a hormoneresponsive niche signaling program by activating expression of factors that regulate epithelial stem cells as well as receptors for the mammatrophic hormones estrogen and growth hormone.Whereas prior studies implicate stem cell defects in human disease, this work shows that niche dysfunction may also cause disease, with possible relevance for human disorders and in particular the breast growth pathogenesis associated with combined pituitary hormone deficiency. Copyright 2016 by the American Association for the Advancement of Science, all rights reserved.116Ysciescopu

SU(2) Calorons and Magnetic Monopoles

We investigate the self-dual Yang-Mills gauge configurations on $R^3\times S^1$ when the gauge symmetry SU(2) is broken to U(1) by the Wilson loop. We construct the explicit field configuration for a single instanton by the Nahm method and show that an instanton is composed of two self-dual monopoles of opposite magnetic charge. We normalize the moduli space metric of an instanton and study various limits of the field configuration and its moduli space metric.Comment: 17 pages, RevTex, 1 Figur

Fractal Image Coding as Projections Onto Convex Sets

Abstract. We show how fractal image coding can be viewed and gen-eralized in terms of the method of projections onto convex sets (POCS). In this approach, the fractal code denes a set of spatial domain sim-ilarity constraints. We also show how such a reformulation in terms of POCS allows additional contraints to be imposed during fractal image decoding. Two applications are presented: image construction with an incomplete fractal code and image denoising.

Nucleon Charge and Magnetization Densities from Sachs Form Factors

Relativistic prescriptions relating Sachs form factors to nucleon charge and magnetization densities are used to fit recent data for both the proton and the neutron. The analysis uses expansions in complete radial bases to minimize model dependence and to estimate the uncertainties in radial densities due to limitation of the range of momentum transfer. We find that the charge distribution for the proton is significantly broad than its magnetization density and that the magnetization density is slightly broader for the neutron than the proton. The neutron charge form factor is consistent with the Galster parametrization over the available range of Q^2, but relativistic inversion produces a softer radial density. Discrete ambiguities in the inversion method are analyzed in detail. The method of Mitra and Kumari ensures compatibility with pQCD and is most useful for extrapolating form factors to large Q^2.Comment: To appear in Phys. Rev. C. Two new figures and accompanying text have been added and several discussions have been clarified with no significant changes to the conclusions. Now contains 47 pages including 21 figures and 2 table

Effect of tensor couplings in a relativistic Hartree approach for finite nuclei

The relativistic Hartree approach describing the bound states of both nucleons and anti-nucleons in finite nuclei has been extended to include tensor couplings for the $\omega$- and $\rho$-meson. After readjusting the parameters of the model to the properties of spherical nuclei, the effect of tensor-coupling terms rises the spin-orbit force by a factor of 2, while a large effective nucleon mass $m^{*}/M_{N} \approx 0.8$ sustains. The overall nucleon spectra of shell-model states are improved evidently. The predicted anti-nucleon spectra in the vacuum are deepened about 20 -- 30 MeV.Comment: 31 pages, 4 postscript figures include

Single- and multi-walled carbon nanotubes viewed as elastic tubes with Young's moduli dependent on layer number

The complete energy expression of a deformed single-walled carbon nanotube (SWNT) is derived in the continuum limit from the local density approximation model proposed by Lenosky {\it et al.} \lbrack Nature (London) {\bf 355}, 333 (1992)\rbrack and shows to be content with the classic shell theory by which the Young's modulus, the Poisson ratio and the effective wall thickness of SWNTs are obtained as $Y=4.70$TPa, $\nu=0.34$, $h=0.75{\rm \AA}$, respectively. The elasticity of a multi-walled carbon nanotube (MWNT) is investigated as the combination of the above SWNTs of layer distance $d=3.4 {\rm \AA}$ and the Young's modulus of the MWNT is found to be an apparent function of the number of layers, $N$, varying from 4.70TPa to 1.04TPa for N=1 to $\infty$.Comment: 4 pages, 1 figur

Association between topical corticosteroid use and type 2 diabetes in two European population-based adult cohorts

BackgroundTopical corticosteroids (CS) are commonly used to treat inflammatory skin conditions including eczema and psoriasis. While topical CS package inserts describe hyperglycaemia and glycosuria as adverse drug reactions, it is unclear whether topical CS use in real life is also associated with an increased risk of type 2 diabetes (T2D).MethodsTwo matched case-control studies and one cohort study were conducted using routinely collected healthcare data from Denmark the UK. A total of 115,218 and 54,944 adults were identified as cases with new onset T2D in the Danish and UK case-control study, respectively. For the Danish cohort study, 2,689,473 adults were included. The main exposure was topical CS and the outcome was incident T2D.ResultsTopical CS was significantly associated with T2D in the Danish (adjusted OR 1ꞏ35; 95% CI 1ꞏ33- 1ꞏ38) and UK (adjusted OR 1ꞏ23; 95% CI 1ꞏ19-1ꞏ27) case-control studies. Individuals who were exposed to topical CS had significantly increased risk of incident T2D (adjusted HR 1ꞏ27; 95% CI 1ꞏ26-1ꞏ29). We observed significant dose-response relationships between T2D and increasing potency of topical CS in the two Danish studies. The results were consistent across all sensitivity analyses.ConclusionsWe found a positive association between topical CS prescribing and incident T2D in Danish and UK adult populations. Clinicians should be cognizant of possible diabetogenic effects of potent topical CS

Continuous-distribution puddle model for conduction in trilayer graphene

An insulator-to-metal transition is observed in trilayer graphene based on the temperature dependence of the resistance under different applied gate voltages. At small gate voltages the resistance decreases with increasing temperature due to the increase in carrier concentration resulting from thermal excitation of electron-hole pairs. At large gate voltages excitation of electron-hole pairs is suppressed, and the resistance increases with increasing temperature because of the enhanced electron-phonon scattering. We find that the simple model with overlapping conduction and valence bands, each with quadratic dispersion relations, is unsatisfactory. Instead, we conclude that impurities in the substrate that create local puddles of higher electron or hole densities are responsible for the residual conductivity at low temperatures. The best fit is obtained using a continuous distribution of puddles. From the fit the average of the electron and hole effective masses can be determined.Comment: 18 pages, 5 figure

Exploring passenger rail markets using new station catchment size and shape metrics

This paper presents a novel spatial market segmentation method to determine key user groups of a train station (such as gender, age and access mode), based on the size and shape of the station catchment area of each group. Two new indices–area ratio and composite ratio–are developed to quantify the importance of user groups for a train station. This method is applied to identify key user groups at seven train stations in Perth, Western Australia. The study offers a new way to explore the travel behaviour of train users and provides insights for rail transport planning and marketing