The effect of varying target size on negative relative accommodation (NRA) and positive relative accommodation (PRA)

Clinical testing of negative relative accommodation (NRA) and positive relative accommodation (PRA) requires a nearpoint chart using small type. Most often, a 20/20 acuity demand is used and is considered to be the standard for these tests. Though it is understood that using different acuity demands affects the endpoints of these tests, differences have yet to be quantified for case analysis purposes. This study compares the endpoints of NRA and PRA with varying acuity demands and quantifies the differences. Fifty-six optometry students ranging in age from 22 to 38 years were tested using standard NRA and PRA test protocols on a specially constructed nearpoint card consisting of 20/20, 20/25, and 20/30 Snellen acuity lines of letters. Statistically significant differences were found in both blur-out and recovery values between each acuity demand on the NRA and PRA. Additionally, most mean values comparing monocular to binocular endpoints were statistically different. Results from this study demonstrate that different endpoints should be expected when using nonstandard targets or acuity demands for accommodative testing

Gene Expression Modifications by Temperature-Toxicants Interactions in Caenorhabditis elegans

Although organophosphorus pesticides (OP) share a common mode of action, there is increased awareness that they elicit a diverse range of gene expression responses. As yet however, there is no clear understanding of these responses and how they interact with ambient environmental conditions. In the present study, we investigated genome-wide gene expression profiles in the nematode Caenorhabditis elegans exposed to two OP, chlorpyrifos and diazinon, in single and combined treatments at different temperatures. Our results show that chlorpyrifos and diazinon induced expression of different genes and that temperature affected the response of detoxification genes to the pesticides. The analysis of transcriptional responses to a combination of chlorpyrifos and diazinon shows interactions between toxicants that affect gene expression. Furthermore, our combined analysis of the transcriptional responses to OP at different temperatures suggests that the combination of OP and high temperatures affect detoxification genes and modified the toxic levels of the pesticides

A Novel 3-Hydroxysteroid Dehydrogenase That Regulates Reproductive Development and Longevity

A multidisciplinary approach identifies novel biochemical activities involved in the synthesisof C. elegans bile acid-like steroids, which act as hormones that regulate sterol metabolism and longevity

A Radio-to-mm Census of Star-forming Galaxies in Protocluster 4C23.56 at Z = 2.5:Gas Mass and Its Fraction Revealed with ALMA

We investigate gas contents of star-forming galaxies associated with protocluster 4C23.56 at z = 2.49 by using the redshifted CO (3-2) and 1.1 mm dust continuum with the Atacama Large Millimeter/submillimeter Array. The observations unveil seven CO detections out of 22 targeted Hα emitters (HAEs) and four out of 19 in 1.1 mm dust continuum. They have high stellar mass ({M}\star > 4× {10}10 M ⊙) and exhibit a specific star-formation rate typical of main-sequence star-forming galaxies at z˜ 2.5. Different gas-mass estimators from CO (3-2) and 1.1 mm yield consistent values for simultaneous detections. The gas mass ({M}{gas}) and gas fraction ({f}{gas}) are comparable to those of field galaxies, with {M}{gas}=[0.3,1.8]× {10}11× ({α }{CO}/(4.36× A(Z))) {M}⊙ , where {α }{CO} is the CO-to-H2 conversion factor and A(Z) is the additional correction factor for the metallicity dependence of {α }{CO}, and < {f}{gas}> =0.53+/- 0.07 from CO (3-2). Our measurements place a constraint on the cosmic gas density of high-z protoclusters, indicating that the protocluster is characterized by a gas density higher than that of the general fields by an order of magnitude. We found ρ ({H}2)˜ 5× {10}9 {M}⊙ {{Mpc}}-3 with the CO(3-2) detections. The five ALMA CO detections occur in the region of highest galaxy surface density, where the density positively correlates with global star-forming efficiency (SFE) and stellar mass. Such correlations possibly indicate a critical role of the environment on early galaxy evolution at high-z protoclusters, though future observations are necessary for confirmation