Maximum human objectively measured pharmacologically stimulated accommodative amplitude

Purpose: To measure the maximum, objectively measured, accommodative amplitude, produced by pharmacologic stimulation. Methods: Thirty-seven healthy subjects were enrolled, with a mean age of 20.2±1.1 years, corrected visual acuity of 20/20, and mean spherical equivalent refraction (SER) =–0.83±1.60 diopters. For each subject, the right pupil was dilated with phenylephrine 10%. After 30 minutes, the pupil was measured, the left eye was patched, and the right eye was autorefracted. Pilocarpine 4% was then instilled in the right eye, followed by phenylephrine. At 45 minutes after the pilocarpine, autorefraction and pupil size were again measured. Results: Mean pupil size pre- and postpilocarpine was 8.0±0.8 mm and 4.4±1.9 mm, respectively. Pre- and postpilocarpine, the mean SER was –0.83±1.60 and –10.55±4.26 diopters, respectively. The mean pilocarpine-induced accommodative amplitude was 9.73±3.64 diopters. Five subjects had accommodative amplitudes ≥14.00 diopters. Accommodative amplitude was not significantly related to baseline SER (p-value =0.24), pre- or postpilocarpine pupil size (p-values =0.13 and 0.74), or change in pupil size (p-value =0.37). Iris color did not statistically significantly affect accommodative amplitude (p-value =0.83). Conclusion: Following topically applied pilocarpine, the induced objectively measured accommodation in the young eye is greater than or equal to the reported subjectively measured voluntary maximum accommodative amplitude

Kinetics of early stages of resorcinol-formaldehyde polymerization investigated by solution phase nuclear magnetic resonance spectroscopy

Resorcinol and formaldehyde reactions were quantitatively monitored by means of 1H and 13C NMR spectroscopy at room temperature (293 K) before heat treatment leading to formation of organic gels. We found that resorcinol substitution with formaldehyde starts with an initial surprisingly rapid step followed by a more gradual depletion of the reactants. Substituted species with both monomeric and dimeric hydroxymethyl groups were observed immediately after mixing of the reagents with the proportion of formaldehyde-based solution species consumed between 30 and 50%. Substituted resorcinol species can be all accounted for by solution-phase NMR at ambient conditions before they form nanoscale clusters upon heating. It can therefore be expected that the final properties of resorcinol-formaldehyde gels depend not only on the composition of reaction mixtures and duration of the high temperature treatment but also on the manner and period of reagent mixing (a hitherto overlooked synthesis step), as different amounts of alternatively substituted resorcinol can be produced before heat treatment commences

Substantiating harm reduction and supporting tobacco regulatory science

A framework for the assessment of novel next-generation tobacco and nicotine products with the potential to reduce health risks compared with cigarettes should integrate scientific studies incorpor..

Twenty-five-year outcomes after multiple internal thoracic artery bypass

ObjectiveCoronary artery bypass grafting with multiple internal thoracic artery grafts is currently controversial. This study assessed single institutional outcomes with multiple internal thoracic artery grafting for guidance with future clinical decisions.MethodsIn 19,482 patients undergoing multivessel coronary artery bypass grafting (1984-2009), baseline characteristics were recorded in a prospective databank, and follow-up was obtained by questionnaires, phone contact, or National Death Index. Outcomes examined were subsequent myocardial infarction, percutaneous coronary intervention, reoperative coronary artery bypass grafting, all-cause death, and a composite of the 4. Three groups were defined: (1) no internal thoracic artery graft (1874/19,482 or 9%); (2) single internal thoracic artery grafts and adjunctive venous conduits (single internal thoracic artery; 16,881/19,482 or 87%); and (3) multiple internal thoracic artery grafts (728/19,482 or 4%). Multivariable Cox modeling adjusted for differences in baseline characteristics, and comparisons were performed using area under the curve analysis.ResultsDifferences in baseline characteristics for the no internal thoracic artery graft, single internal thoracic artery, and multiple internal thoracic artery groups were as follows: median age 66, 64, and 59 years, respectively; congestive heart failure 22%, 18%, and 13%, respectively; ejection fraction 0.50, 0.52, and 0.51, respectively; reoperation 10%, 3%, and 7%, respectively; diabetes 27%, 30%, and 15%, respectively; and female gender 33%, 28%, and 20%, respectively. No differences existed in the median number of diseased vessels (3, 3, and 3, respectively) or number of grafts per patient (3, 3, and 3, respectively). Composite outcome improved with increasing internal thoracic artery grafts, whether assessing unadjusted or risk-adjusted data. Compared with no internal thoracic artery graft, the adjusted hazard ratio was 0.79 (confidence interval, 0.74-0.83) for single internal thoracic artery grafting and 0.70 (confidence interval, 0.62-0.80) for multiple internal thoracic artery grafting (both P < .001), reducing risk by 21% and 30%, respectively.ConclusionsThis study confirms improved patient outcomes with multiple internal thoracic artery grafting, achieving half again as much benefit as single internal thoracic artery grafting alone. The data suggest that increasing application of multiple internal thoracic artery grafting should be encouraged to mitigate the inherent risks and costs of long-term cardiac events

(16) Psyche: A mesosiderite-like asteroid?

Asteroid (16) Psyche is the target of the NASA Psyche mission. It is considered one of the few main-belt bodies that could be an exposed proto-planetary metallic core and that would thus be related to iron meteorites. Such an association is however challenged by both its near- and mid-infrared spectral properties and the reported estimates of its density. Here, we aim to refine the density of (16) Psyche to set further constraints on its bulk composition and determine its potential meteoritic analog. We observed (16) Psyche with ESO VLT/SPHERE/ZIMPOL as part of our large program (ID 199.C-0074). We used the high angular resolution of these observations to refine Psyche's three-dimensional (3D) shape model and subsequently its density when combined with the most recent mass estimates. In addition, we searched for potential companions around the asteroid. We derived a bulk density of 3.99\,$\pm$\,0.26\,g$\cdot$cm$^{-3}$ for Psyche. While such density is incompatible at the 3-sigma level with any iron meteorites ($\sim$7.8\,g$\cdot$cm$^{-3}$), it appears fully consistent with that of stony-iron meteorites such as mesosiderites (density $\sim$4.25\,$\cdot$cm$^{-3}$). In addition, we found no satellite in our images and set an upper limit on the diameter of any non-detected satellite of 1460\,$\pm$\,200}\,m at 150\,km from Psyche (0.2\%\,$\times$\,R$_{Hill}$, the Hill radius) and 800\,$\pm$\,200\,m at 2,000\,km (3\%\,$\times$\,$R_{Hill}$). Considering that the visible and near-infrared spectral properties of mesosiderites are similar to those of Psyche, there is merit to a long-published initial hypothesis that Psyche could be a plausible candidate parent body for mesosiderites.Comment: 16 page

Thermal properties of large main-belt asteroids observed by Herschel PACS

Non-resolved thermal infrared observations enable studies of thermal and physical properties of asteroid surfaces provided the shape and rotational properties of the target are well determined via thermo-physical models. We used calibration-programme Herschel PACS data (70, 100, 160 $\mu$m) and state-of-the-art shape models derived from adaptive-optics observations and/or optical light curves to constrain for the first time the thermal inertia of twelve large main-belt asteroids. We also modelled previously well-characterised targets such as (1) Ceres or (4) Vesta as they constitute important benchmarks. Using the scale as a free parameter, most targets required a re-scaling $\sim$5\% consistent with what would be expected given the absolute calibration error bars. This constitutes a good cross-validation of the scaled shape models, although some targets required larger re-scaling to reproduce the IR data. We obtained low thermal inertias typical of large main belt asteroids studied before, which continues to give support to the notion that these surfaces are covered by fine-grained insulating regolith. Although the wavelengths at which PACS observed are longwards of the emission peak for main-belt asteroids, they proved to be extremely valuable to constrain size and thermal inertia and not too sensitive to surface roughness. Finally, we also propose a graphical approach to help examine how different values of the exponent used for scaling the thermal inertia as a function of heliocentric distance (i.e. temperature) affect our interpretation of the results.Comment: Accepted for publication in Astronomy & Astrophysics (preprint version

Transit Timing Observations from Kepler: VII. Confirmation of 27 planets in 13 multiplanet systems via Transit Timing Variations and orbital stability

We confirm 27 planets in 13 planetary systems by showing the existence of statistically significant anti-correlated transit timing variations (TTVs), which demonstrates that the planet candidates are in the same system, and long-term dynamical stability, which places limits on the masses of the candidates---showing that they are planetary. %This overall method of planet confirmation was first applied to \kepler systems 23 through 32. All of these newly confirmed planetary systems have orbital periods that place them near first-order mean motion resonances (MMRs), including 6 systems near the 2:1 MMR, 5 near 3:2, and one each near 4:3, 5:4, and 6:5. In addition, several unconfirmed planet candidates exist in some systems (that cannot be confirmed with this method at this time). A few of these candidates would also be near first order MMRs with either the confirmed planets or with other candidates. One system of particular interest, Kepler-56 (KOI-1241), is a pair of planets orbiting a 12th magnitude, giant star with radius over three times that of the Sun and effective temperature of 4900 K---among the largest stars known to host a transiting exoplanetary system.Comment: 12 pages, 13 figures, 5 tables. Submitted to MNRA

North Flinders Reef (Coral Sea, Australia) Porites sp. corals as a candidate Global Boundary Stratotype Section and Point for the Anthropocene Series

Corals are unique in the suite of proposed Anthropocene Global Boundary Stratotype Section and Point (GSSP) archives, as living organisms that produce aragonite exoskeletons preserved in the geological record that contain highly accurate and precise (<±1 year) internal chronologies. The GSSP candidate site North Flinders Reef in the Coral Sea (Australia) is an offshore oceanic reef, and therefore less vulnerable to local human influences than those closer to the coast. Here, we present geochemical records from two Porites sp. corals sampled at an annual to pluri-annual (i.e. 3–5 years) resolution that shows clear global and regional human impacts. Atmospheric nuclear bomb testing by-products (14C,239+240Pu) show a clear increase in the Flinders Reef corals coincident with well-dated nuclear testing operations. By contrast, the radionuclides 241Am and 137Cs are present at low or undetectable levels, as are spheroidal carbonaceous fly-ash particles. Coral δ13C shows centennial variability likely influenced by growth effects in the 18th century and with a progression to lower values starting in 1880 and accelerating post-1970. The latter may be related to the Suess Effect resulting from 13C-depleted fossil fuel burning. Coral δ15N decreased between 1710 and 1954 with a reversal post-1954. Coral temperature proxies indicate prominent centennial variability with equally warm conditions in the 18th and end of 20th century. However, the exact mechanisms responsible for the mid-20th century changes in these parameters need to be scrutinised in further detail. Plain Language summary: This work proposes a candidate natural archive for the official marker of the Anthropocene that geologists will use to mark this important interval in time. Our candidate is a live coral from North Flinders Reef in the Coral Sea (Australia), located 150 km east of the Great Barrier Reef, a location that is remote from direct local human influences. Corals are a unique archive of tropical ocean change because they incorporate the geochemical signature from seawater into their limestone skeleton during their long life-spans. Here we investigated a number of geochemical markers in yearly growth layers of the corals to define several markers for the Anthropocene based on changes in temperature, water chemistry, chemicals from pollution and fertilisers, radioactive products from nuclear bomb testing, and by-products from burning fossil fuels. We have detected clear human influences in several of these markers

The East Gotland Basin (Baltic Sea) as a candidate Global Boundary Stratotype Section and Point for the Anthropocene series

The short sediment core EMB201/7-4 retrieved from the East Gotland Basin, central Baltic Sea, is explored here as a candidate to host the stratigraphical basis for the Anthropocene series and its equivalent Anthropocene epoch, still to be formalized in the Geological Time Scale. The core has been accurately dated back to 1840 CE using a well-established event stratigraphy approach. A pronounced and significant change occurs at 26.5 cm (dated 1956 ± 4 CE) for a range of geochemical markers including 239+240Pu, 241Am, fly-ash particles, DDT (organochlorine insecticide), total organic carbon, and bulk organic carbon stable isotopes. This stratigraphic level, which corresponds to a change in both lithology and sediment colour related to early anthropogenic-triggered eutrophication of the central Baltic Sea, is proposed as a Global Boundary Stratotype Section and Point for the Anthropocene series