Eyelid Cosmetic Enhancements and Their Associated Ocular Adverse Effects

Numerous cosmetic enhancements and augmentations to the natural appearance of the periorbital area are readily available today. Due to the increasing popularity of these cosmetic procedures, it is important for ophthalmologists to be aware of their potential risks, complications and adverse effects. The aim of this literature review was to introduce some of the most common ocular cosmetic enhancements and provide a comprehensive overview of their associated adverse effects reported in various medical journals. PubMed, Embase, and Google Scholar were used to identify articles related to the following ocular cosmetic procedures; eyelash extensions, permanent eyelid tattooing, and eyelash dyeing. The most common complication associated with eyelash extensions was allergic blepharitis (79%). Allergic granulomatous reactions were the predominant complication in patients who underwent eyelid tattooing (56%). Besides, 60% of subjects who underwent eyelash dyeing experienced allergic contact dermatitis as the most common adverse effect. Although millions of these procedures are performed annually without any adverse effects, reports of complications continue to increase in the literature. Knowledge of the possible adverse effects associated with these enhancements is important for eye care providers and licensed estheticians to be aware of given both the direct and indirect effects they may have on ocular health and visual outcomes

Eyelid Cosmetic Enhancements and Their Associated Ocular Adverse Effects

Numerous cosmetic enhancements and augmentations to the natural appearance of the periorbital area are readily available today. Due to the increasing popularity of these cosmetic procedures, it is important for ophthalmologists to be aware of their potential risks, complications and adverse effects. The aim of this literature review was to introduce some of the most common ocular cosmetic enhancements and provide a comprehensive overview of their associated adverse effects reported in various medical journals. PubMed, Embase, and Google Scholar were used to identify articles related to the following ocular cosmetic procedures; eyelash extensions, permanent eyelid tattooing, and eyelash dyeing. The most common complication associated with eyelash extensions was allergic blepharitis (79%). Allergic granulomatous reactions were the predominant complication in patients who underwent eyelid tattooing (56%). Besides, 60% of subjects who underwent eyelash dyeing experienced allergic contact dermatitis as the most common adverse effect. Although millions of these procedures are performed annually without any adverse effects, reports of complications continue to increase in the literature. Knowledge of the possible adverse effects associated with these enhancements is important for eye care providers and licensed estheticians to be aware of given both the direct and indirect effects they may have on ocular health and visual outcomes

A Revised Model for the Formation of Disk Galaxies: Low Spin and Dark-Halo Expansion

We use observed rotation velocity-luminosity (VL) and size-luminosity (RL) relations to single out a specific scenario for disk galaxy formation in the LCDM cosmology. Our model involves four independent log-normal random variables: dark-halo concentration c, disk spin lam_gal, disk mass fraction m_gal, and stellar mass-to-light ratio M/L_I. A simultaneous match of the VL and RL zero points with adiabatic contraction requires low-c halos, but this model has V_2.2~1.8 V_vir (where V_2.2 and V_vir are the circular velocity at 2.2 disk scale lengths and the virial radius, respectively) which will be unable to match the luminosity function (LF). Similarly models without adiabatic contraction but standard c also predict high values of V_2.2/V_vir. Models in which disk formation induces an expansion rather than the commonly assumed contraction of the dark-matter halos have V_2.2~1.2 V_vir which allows a simultaneous fit of the LF. This may result from non-spherical, clumpy gas accretion, where dynamical friction transfers energy from the gas to the dark matter. This model requires low lam_gal and m_gal values, contrary to naive expectations. However, the low lam_gal is consistent with the notion that disk galaxies predominantly survive in halos with a quiet merger history, while a low m_gal is also indicated by galaxy-galaxy lensing. The smaller than expected scatter in the RL relation, and the lack of correlation between the residuals of the VL and RL relations, respectively, imply that the scatter in lam_gal and in c need to be smaller than predicted for LCDM halos, again consistent with the idea that disk galaxies preferentially reside in halos with a quiet merger history.Comment: 28 pages, 16 figures, ApJ accepted, minor changes from unpublished version, uses emulateapj.cls, high-resolution version available at http://www.ucolick.org/~dutton/65200/hi-res-version/ms.dutton.v2_hr.p

A global analysis of viviparity in squamates highlights its prevalence in cold climates

Aim Viviparity has evolved more times in squamates than in any other vertebrate group; therefore, squamates offer an excellent model system in which to study the patterns, drivers and implications of reproductive mode evolution. Based on current species distributions, we examined three selective forces hypothesized to drive the evolution of squamate viviparity (cold climate, variable climate and hypoxic conditions) and tested whether viviparity is associated with larger body size. Location Global. Time period Present day. Taxon Squamata. Methods We compiled a dataset of 9061 squamate species, including their distributions, elevation, climate, body mass and reproductive modes. We applied species-level and assemblage-level approaches for predicting reproductive mode, both globally and within biogeographical realms. We tested the relationships of temperature, interannual and intra-annual climatic variation, elevation (as a proxy for hypoxic conditions) and body mass with reproductive mode, using path analyses to account for correlations among the environmental predictors. Results Viviparity was strongly associated with cold climates at both species and assemblage levels, despite the prevalence of viviparity in some warm climates. Viviparity was not clearly correlated with climatic variability or elevation. The probability of being viviparous exhibited a weak positive correlation with body size. Conclusions Although phylogenetic history is important, potentially explaining the occurrence of viviparous species in regions that are warm at present, current global squamate distribution is characterized by a higher relative abundance of viviparity in cold environments, supporting the prediction of the “cold-climate” hypothesis. The roles of climatic variation and hypoxia are less important and not straightforward. Elevation probably exerts various selective pressures and influences the prevalence of viviparity primarily through its effect on temperature rather than on oxygen concentration

The baryonic Tully-Fisher relation and galactic outflows

Most of the baryons in the Universe are not in the form of stars and cold gas in galaxies. Galactic outflows driven by supernovae/stellar winds are the leading mechanism for explaining this fact. The scaling relation between galaxy mass and outer rotation velocity (also known as the baryonic Tully-Fisher relation, BTF) has recently been used as evidence against this viewpoint. We use a LCDM based semi-analytic disk galaxy formation model to investigate these claims. In our model, galaxies with less efficient star formation and higher gas fractions are more efficient at ejecting gas from galaxies. This is due to the fact that galaxies with less efficient star formation and higher gas fractions tend to live in dark matter haloes with lower circular velocities, from which less energy is required to escape the potential well. In our model the intrinsic scatter in the BTF is 0.15 dex, and mostly reflects scatter in dark halo concentration. The observed scatter, equal to 0.24 dex, is dominated by measurement errors. The best estimate for the intrinsic scatter is that it is less than 0.15 dex, and thus our LCDM based model (which does not include all possible sources of scatter) is only just consistent with this. In our model, gas rich galaxies, at fixed virial velocity (V_vir), with lower stellar masses have lower baryonic masses. This is consistent with the expectation that galaxies with lower stellar masses have had less energy available to drive an outflow. However, when the outer rotation velocity (V_flat) is used the correlation has the opposite sign, with a slope in agreement with observations. This is due to scatter in the relation between V_flat and V_vir. In summary, contrary to some previous claims, we show that basic features of the BTF are consistent with a LCDM based model in which the low efficiency of galaxy formation is determined by galactic outflows.Comment: 7 pages, 4 figures, accepted to MNRA

Elastic and quasi-elastic pppp and γ⋆p\gamma^\star p scattering in the Dipole Model

We have in earlier papers presented an extension of Mueller's dipole cascade model, which includes sub-leading effects from energy conservation and running coupling as well as colour suppressed saturation effects from pomeron loops via a ``dipole swing''. The model was applied to describe the total and diffractive cross sections in $pp$ and $\gamma^*p$ collisions, and also the elastic cross section in $pp$ scattering. In this paper we extend the model to describe the corresponding quasi-elastic cross sections in $\gamma^*p$, namely the exclusive production of vector mesons and deeply virtual compton scattering. Also for these reactions we find a good agrement with measured cross sections. In addition we obtain a reasonable description of the $t$-dependence of the elastic $pp$ and quasi-elastic $\gamma^\star p$ cross sections

An Investigation of Sloan Digital Sky Survey Imaging Data and Multi-Band Scaling Relations of Spiral Galaxies (with Dynamical Information)

We have compiled a sample of 3041 spiral galaxies with multi-band gri imaging from the Sloan Digital Sky Survey (SDSS) Data Release 7 and available galaxy rotational velocities derived from HI line widths. We compare the data products provided through the SDSS imaging pipeline with our own photometry of the SDSS images, and use the velocities (V) as an independent metric to determine ideal galaxy sizes (R) and luminosities (L). Our radial and luminosity parameters improve upon the SDSS DR7 Petrosian radii and luminosities through the use of isophotal fits to the galaxy images. This improvement is gauged via VL and RV relations whose respective scatters are reduced by ~8% and ~30% compared to similar relations built with SDSS parameters. The tightest VRL relations are obtained with the i-band radius, R235i, measured at 23.5 mag/arcsec^-2, and the luminosity L235i, measured within R235i. Our VRL scaling relations compare well, both in scatter and slope, with similar studies (such comparisons however depend sensitively on the nature and size of the compared samples). The typical slopes, b, and observed scatters, sigma, of the i-band VL, RL and RV relations are bVL=0.27+/-0.01, bRL=0.41+/-0.01, bRV=1.52+/-0.07, and sigmaVL=0.074, sigmaRL=0.071, sigmaRV=0.154 dex. Similar results for the SDSS g and r bands are also provided. Smaller scatters may be achieved for more pruned samples. We also compute scaling relations in terms of the baryonic mass (stars + gas), Mbar, ranging from 10^8.7 Msol to 10^11.6 Msol. Our baryonic velocity-mass (VM) relation has slope 0.29+/-0.01 and a measured scatter sigma_meas = 0.076 dex. While the observed VL and VM relations have comparable scatter, the stellar and baryonic VM relations may be intrinsically tighter, and thus potentially more fundamental, than other VL relations of spiral galaxies.Comment: Submitted to MNRAS, comments welcom