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A cosmology calculator that computes times and distances as a function of redshift for user‐defined cosmological parameters has been made available online. This paper gives the formulae used by the cosmology calculator and discusses some of its implementation. A version of the calculator that allows one to specify the equation‐of‐state parameterwand \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $w^{\\prime }$ \\end{document} , and one for converting the light‐travel times usually given in the popular press into redshifts, is also located at the same site.

Background Uveitis presumed to be secondary to Mycobacterium tuberculosis is a rare but potentially blinding condition. Difficulty in making an accurate diagnosis and the low incidence of TB uveitis (TBU) contribute to the lack of evidence regarding the best management of this condition. This systematic review aims to analyse existing research to provide a summary of the literature regarding the utility of TB therapy for the management of TBU. Methods This systematic review was prospectively registered on PROSPERO (PROSPERO 2021 CRD42021273379). We searched Medline, Embase and Central databases, and the search was done on 20th June 2023 with an updated literature search. Results We included 55 studies and found that the heterogeneity in the methodology of these studies precluded metanalysis, and a narrative analysis was undertaken. Risk of bias analysis was undertaken using the Newcastle–Ottawa scale. Conclusions Key findings of this systematic review include multiple systemic biases in the available evidence, and general lack of control for confounding variables. This results in many unanswered questions regarding the utility of TB therapy for TBU and reinforces the need for more data in this area.

Aims/Hypothesis To determine if acute overexpression of peroxisome proliferator-activated receptor, gamma, coactivator 1 beta ( Pgc-1β [also known as Ppargc1b ]) in skeletal muscle improves insulin action in a rodent model of diet-induced insulin resistance. Methods Rats were fed either a low-fat or high-fat diet (HFD) for 4 weeks. In vivo electroporation was used to overexpress Pgc-1β in the tibialis cranialis (TC) and extensor digitorum longus (EDL) muscles. Downstream effects of Pgc-1β on markers of mitochondrial oxidative capacity, oxidative stress and muscle lipid levels were characterised. Insulin action was examined ex vivo using intact muscle strips and in vivo via a hyperinsulinaemic–euglycaemic clamp. Results Pgc-1β gene expression was increased >100% over basal levels. The levels of proteins involved in mitochondrial function, lipid metabolism and antioxidant defences, the activity of oxidative enzymes, and substrate oxidative capacity were all increased in muscles overexpressing Pgc-1β. In rats fed a HFD, increasing the levels of Pgc-1β partially ameliorated muscle insulin resistance, in association with decreased levels of long-chain acyl-CoAs (LCACoAs) and increased antioxidant defences. Conclusions Our data show that an increase in Pgc-1β expression in vivo activates a coordinated subset of genes that increase mitochondrial substrate oxidation, defend against oxidative stress and improve lipid-induced insulin resistance in skeletal muscle.

A field study was conducted on a small urban watershed (residential and golf course dominated) in southern Nevada to assess the concentration and speciation of selenium (Se) in a series of drain lines and monitoring wells and to quantify the mass discharge of Se from the drain system. Water samples were collected on a monthly basis and analyzed for total Se, selenate (SeO₄ ⁼) and selenite (SeO₃ ⁼). In addition, where possible, flow was assessed as was, temperature, redox potential, pH, dissolved oxygen (DO) along with all major cations and anions. The data were then modeled with PhreeqC to identify selenium speciation. Results revealed a SeO₄ ⁼ dominated system with SeO₄ ⁼ concentrations ranging from 13 to 62 ppb. In the monitoring wells, 66 % of the variation in the total Se concentration could be described based on depth to groundwater, temperature and sulfate concentrations (P < 0.001). In particular, higher total Se concentrations were predicted for shallower depth to groundwater, suggesting the solubilization of Se evapo-concentrates near the surface could be reduced by lowering water tables. The highest of all correlations was found between SeO₄ ⁼ concentrations (↑) and the sodium (↑) and DO (↑) concentrations in the monitoring wells (R ² = 0.77, P < 0.001). An excellent curvilinear relationship was found between total Se and the electrical conductivity in the water (R ² = 0.73, P < 0.001). Based on the Se data and time line identified in this study, high concentrations of Se could be expected to drain from this area for many years to come, with salinity acting as a good proxy for Se concentration. In the drain lines, Se concentrations were found to be invariant to flow (P > 0.05). Flow discharge from the main drain system to the Las Vegas Wash was estimated at 559 acre feet during the 1 year study period. This flow was estimated to carry 4,203 Mg of salts 6.71 Mg of nitrate-N and 27.1 kg of total Se.

Bone loss during perimenopause, an estrogen-sufficient period, correlates with elevated serum follicle-stimulating hormone (FSH) and decreased inhibins A and B. Utilizing a recently described ovotoxin-induced animal model of perimenopause characterized by a prolonged estrogen-replete period of elevated FSH, we examined longitudinal changes in bone mineral density (BMD) and their association with FSH. Additionally, serum inhibin levels were assessed to determine whether elevated FSH occurred secondary to decreased ovarian inhibin production and, if so, whether inhibins also correlated with BMD. BMD of the distal femur was assessed using dual-energy X-ray absorptiometry (DXA) over 19 months in Sprague-Dawley rats treated at 1 month with vehicle or 4-vinylcyclohexene diepoxide (VCD, 80 or 160 mg/kg daily). Serum FSH, inhibins A and B, and 17-ß estradiol (E 2 ) were assayed and estrus cyclicity was assessed. VCD caused dose-dependent increases in FSH that exceeded values occurring with natural senescence, hastening the onset and prolonging the duration of persistent estrus, an acyclic but E 2 -replete period. VCD decreased serum inhibins A and B, which were inversely correlated with FSH ( r 2  = 0.30 and 0.12, respectively). In VCD rats, significant decreases in BMD (5–13%) occurred during periods of increased FSH and decreased inhibins, while BMD was unchanged in controls. In skeletally mature rats, FSH ( r 2  = 0.13) and inhibin A ( r 2  = 0.15) correlated with BMD, while inhibin B and E 2 did not. Thus, for the first time, both the hormonal milieu of perimenopause and the association of dynamic perimenopausal changes in FSH and inhibin A with decreased BMD have been reproduced in an animal model.

Although water table depth is commonly regarded as the primary determinant of litter decomposition rate in tropical peatlands, this has rarely been tested experimentally. This study explored the influence of flooding on decomposition of litter from three dominant plant species in a neotropical peatland. The non-flooded treatment reduced the mass remaining after 14 months from 84 to 81 % for Raphia taedigera , 65 to 58 % for Campnosperma panamensis , and 69 to 58 % for Cyperus sp. The proportions of carbon, nitrogen and phosphorus in the labile, semi-labile and recalcitrant carbon pools, did not reliably predict differences among species in the mass loss rate of litter. Phosphorus was rapidly lost from litter, while carbon losses, including soluble carbon, were slower, but significant for all fractions. The non-flooded treatment substantially reduced the quantity of C remaining in the residue fraction of leaf litter after 12 weeks, with 31, 19 and 6 % less remaining in the non-flooded treatment for R. taedigera , C. panamensis and Cyperus sp. This suggests that lower water table depth on litter decay increase degradation of mainly aliphatic and aromatic carbon in the residual fraction. Thus, although lowering the water table increased decomposition, the chemical composition of litter clearly influences peat accumulation.

ASTEROID collisions are an important source of the dust particles in the zodiacal cloud 1–3 . These particles spiral in towards the Sun under the influence of drag forces 4–6 and, in passing through the inner Solar System, are subject to gravitational perturbations by the planets, which may trap them (at least temporarily) in orbital resonances 7–10 . Recently, numerical simulations have shown that resonances with the Earth are particularly effective at trapping asteroidal dust, leading to the suggestion that the Earth may be embedded in a circumsolar ring of dust 11 . The azimuthal structure of this ring was predicted to be asymmetric, with the region trailing the Earth being substantially more dense than that in the leading direction 11 . This prediction is in both qualitative and quantitative agreement with the asymmetry in zodiacal light observed by the Infrared Astronomical Satellite (IRAS) 11,12 , but the IRAS data alone are equivocal because of calibration uncertainties and sparse coverage of elongation angle 12 . Here we report observations by the Diffuse Infrared Background Experiment 13 (DIRBE) on the Cosmic Background Explorer satellite (COBE) 14 , which confirm both the existence of this ring and the predictions of its near-Earth structure.