Using measured photography to obtain optimal results from CCD Color Scanners

With the advent of desktop color scanners in the electronic prepress production environment, quality in color separations from transmissive originals has become erratic. The cause of this fluctuation is, in part, due to the transition from PMT to CCD-based scanning technology. Whereas, PMT scanners tend to have a broad dynamic range, that of CCD scanners is more limited. This characteristic adversely affects the quality of color separations by causing additional tone compression. An original transparency typically has a shadow density of 3.00 and a diffused highlight density of 0.30 for an overall density range of 2.70. On a four-color heatset web press with coated stock, the maximum reproducible tonal range corresponds to a density of 1.80. The difference in density of 0.90 between the original and the press sheet is unable to fit through the printing window unless it undergoes considerable tone compression. This project was based on two hypotheses. The first was that the lower the tonal range of a transmissive original the more readily lower-midtone-to-shadow tonality could be retained in the separations produced by a CCD scanner and related equipment. The second was that exposure latitude in the separations would decrease with increasing tonal range. The first stage of production was to produce twelve test transparencies by photograph ing a still life set to four tonal ranges: 3.5, 4.5, 5.5, and 6.5 f/stops. Within each range, three images were selected to represent normal exposure, 1/2 f/stop overexposure, and 1/2 f/stop underexposure. Comparison of halftone proofs, made from separations of the normallyexposed transparencies, were later used for the first hypothesis. Proofs from the 1/2 f/stop over- and 1/2 f/stop underexposures were compared with the normal exposures to test the second hypothesis. vm The twelve test transparencies were first scanned on the Dainippon Screen SG-608 to produce a set of best-of-kind reference separations and halftone proofs. Next, the trans parencies were scanned on two midrange 12-bit CCD scanners, one a Pixelcraft CIS 4520RS, the other an Agfa Horizon. Separations for both were produced with Color Access 1.3.3 software on a Macintosh Quadra 700 computer, linked to an Agfa SelectSet 5000 image-setter via an Agfa 5000PS Star Plus RIP. The image files were placed in an 8 1/2 X 11 QuarkXPress page with a 20% gray surround prior to output. Halftone proofs were produced with the Fuji Color Art proofing system, then viewed under 5000 Kelvin lighting. Three methods were used for comparison: visual evaluation by the author, densitometric measurement, and evaluation by 32 independent judges. Only proofs from the two CCD scanners were shown to the judges. Proofs from the SG-608, of noticeably higher quality, were used for reference. The four proofs from separations produced by normally-exposed originals were used to examine the first hypothesis. Two groups of proofs, one for each scanner, were ranked by the judges according to best-to-worst rendition of lower-midtone-to-shadow detail. The rank ings for both groups placed the 3.5 f/stop tonal ranges first, 4.5 f/stop second, 5.5 f/stop third, and 6.5 f/stop fourth. Visual evaluation by the author ranked the proofs in the same order, establishing a 100% correlation. Increases in density range were also expected to follow the 3.5 to 6.5 f/stop ranking. But actual measurements showed increases in density to 4.5 f/stops, then a pronounced drop of 0.25 or greater for the 5.5 and 6.5 f/stop ranges. This demonstated that the higher tonal ranges exceeded the capacity of the CCDs to make a full response, indicating that limited dynamic range was causing abrupt increases in tone compression. To determine the validity of the second hypothesis, the judges examined two groups of twelve proofs each, corresponding to the separations for normal, 1/2 f/stop over- and 1/2 f/stop underexposed originals within each of the four tonal ranges. For the Agfa Horizon, the rankings were 3.5 f/stop tonal range first, 4.5 f/stop second, 5.5 f/stop third, and 6.5 f/stop fourth. With the Pixelcraft CIS 4520RS, the rankings were 3.5 f/stop first, 6.5 f/stop second, 5.5 f/stop third, and 6.5 f/stop fourth. The misranking of the 6.5 f/stop range in second place indicated the difficulty the judges experienced in distinguishing between higher tonal ranges due to the increasing effects of tone compression. Again, densitometric measurements did not support the rank ings of the judges or the author because the densitometer could not distinguish between small tonal range differences due to good exposure latitude and those differences due to blocked shadow tonality resulting from tone compression. A procedure was devised for mathematical assessment of tonal range differences. Using the change in density between adjacent tonal ranges, a value was derived which could be expressed as a fraction of the inital 1 f/stop difference between ranges ( 1 f/stop = 0.30 den sity units). For example, the 3.5 f/stop normal exposure for the Agfa Horizon had a tonal range of 1.73 and the 4.5 f/stop normal exposure had a tonal range of 2.02. The change from 3.5 to 4.5 f/stops is +0.29. Expressed as a percentage, 0.29 -0.30 = 97%. This value showed that the scanner made a nearly complete response in translating tonal range differences in the original transparency to tonal range differences in the separations. Further refinement of these calculations is needed to reflect differences in gamma and tone compression between the original transparencies and the halftone proofs. The findings of this study demonstrate that optimal results from a CCD or PMT scan ner can only be obtained if the tonal range of the original scene is less than 4.5 f/stops. When the 4.5 f/stop range was exceeded, the CCD scanners responded with an immediate deterioration of lower-midtone-to-shadow tonality. In comparison, PMT scanner displayed a more gradual degradation of lower-midtone-to-shadow tonality, in keeping with its greater dynamic range

Promiscuity in the part-phosphorylative Entner–Doudoroff pathway of the archaeon Sulfolobus solfataricus

AbstractThe hyperthermophilic archaeon Sulfolobus solfataricus metabolises glucose and galactose by a ‘promiscuous’ non-phosphorylative variant of the Entner–Doudoroff pathway, in which a series of enzymes have sufficient substrate promiscuity to permit the metabolism of both sugars. Recently, it has been proposed that the part-phosphorylative Entner–Doudoroff pathway occurs in parallel in S. solfataricus as an alternative route for glucose metabolism. In this report we demonstrate, by in vitro kinetic studies of d-2-keto-3-deoxygluconate (KDG) kinase and KDG aldolase, that the part-phosphorylative pathway in S. solfataricus is also promiscuous for the metabolism of both glucose and galactose

Know the Star, Know the Planet. III. A Stellar Companion to the Host Star of the Eccentric Exoplanet HD 8673b

HD 8673 hosts a massive exoplanet in a highly eccentric orbit (e = 0.723). Based on two epochs of speckle interferometry a previous publication identified a candidate stellar companion. We observed HD 8673 multiple times with the 10 m Keck II telescope, the 5 m Hale telescope, the 3.63 m Advanced Electro-Optical System telescope, and the 1.5 m Palomar telescope in a variety of filters with the aim of confirming and characterizing the stellar companion. We did not detect the candidate companion, which we now conclude was a false detection, but we did detect a fainter companion. We collected astrometry and photometry of the companion on six epochs in a variety of filters. The measured differential photometry enabled us to determine that the companion is an early M dwarf with a mass estimate of 0.33–0.45 M_☉. The companion has a projected separation of 10 AU, which is one of the smallest projected separations of an exoplanet host binary system. Based on the limited astrometry collected, we are able to constrain the orbit of the stellar companion to a semimajor axis of 35–60 AU, an eccentricity ≤0.5, and an inclination of 75°–85°. The stellar companion has likely strongly influenced the orbit of the exoplanet and quite possibly explains its high eccentricity

Know The Star, Know the Planet. IV. A Stellar Companion to the Host star of the Eccentric Exoplanet HD 8673b

HD 8673 hosts a massive exoplanet in a highly eccentric orbit (e=0.723). Based on two epochs of speckle interferometry a previous publication identified a candidate stellar companion. We observed HD 8673 multiple times with the 10 m Keck II telescope, the 5 m Hale telescope, the 3.63 m AEOS telescope and the 1.5m Palomar telescope in a variety of filters with the aim of confirming and characterizing the stellar companion. We did not detect the candidate companion, which we now conclude was a false detection, but we did detect a fainter companion. We collected astrometry and photometry of the companion on six epochs in a variety of filters. The measured differential photometry enabled us to determine that the companion is an early M dwarf with a mass estimate of 0.33-0.45 M?. The companion has a projected separation of 10 AU, which is one of the smallest projected separations of an exoplanet host binary system. Based on the limited astrometry collected, we are able to constrain the orbit of the stellar companion to a semi-major axis of 35{60 AU, an eccentricity ? 0.5 and an inclination of 75{85?. The stellar companion has likely strongly in uenced the orbit of the exoplanet and quite possibly explains its high eccentricity.Comment: Accepted to the Astronomical Journal, 6 Pages, 5 Figure

Entangling macroscopic oscillators exploiting radiation pressure

It is shown that radiation pressure can be profitably used to entangle {\it macroscopic} oscillators like movable mirrors, using present technology. We prove a new sufficient criterion for entanglement and show that the achievable entanglement is robust against thermal noise. Its signature can be revealed using common optomechanical readout apparatus.Comment: 4 pages, 2 eps figures, new separability criterion added, new figure 2, authors list change

Generating entangled superpositions of macroscopically distinguishable states within a parametric oscillator

We suggest a variant of the recently proposed experiment for the generation of a new kind of Schroedinger-cat states, using two coupled parametric down-converter nonlinear crystals [F. De Martini, Phys. Rev. Lett. 81, 2842 (1998)]. We study the parametric oscillator case and find that an entangled Schroedinger-cat type state of two cavities, whose mirrors are placed along the output beams of the nonlinear crystals, can be realized under suitable conditions.Comment: RevTeX 17 pages, 9 eps files for 7 figures. Submitted to Physical Review

TESS Hunt for Young and Maturing Exoplanets (THYME) IX: a 27 Myr extended population of Lower-Centaurus Crux with a transiting two-planet system

We report the discovery and characterization of a nearby (~ 85 pc), older (27 +/- 3 Myr), distributed stellar population near Lower-Centaurus-Crux (LCC), initially identified by searching for stars co-moving with a candidate transiting planet from TESS (HD 109833; TOI 1097). We determine the association membership using Gaia kinematics, color-magnitude information, and rotation periods of candidate members. We measure it's age using isochrones, gyrochronology, and Li depletion. While the association is near known populations of LCC, we find that it is older than any previously found LCC sub-group (10-16 Myr), and distinct in both position and velocity. In addition to the candidate planets around HD 109833 the association contains four directly-imaged planetary-mass companions around 3 stars, YSES-1, YSES-2, and HD 95086, all of which were previously assigned membership in the younger LCC. Using the Notch pipeline, we identify a second candidate transiting planet around HD 109833. We use a suite of ground-based follow-up observations to validate the two transit signals as planetary in nature. HD 109833 b and c join the small but growing population of <100 Myr transiting planets from TESS. HD 109833 has a rotation period and Li abundance indicative of a young age (< 100 Myr), but a position and velocity on the outskirts of the new population, lower Li levels than similar members, and a CMD position below model predictions for 27 Myr. So, we cannot reject the possibility that HD 109833 is a young field star coincidentally nearby the population.Comment: 23 pages, 15 figures, Accepted for publication in A

Cohort profile for the STratifying Resilience and Depression Longitudinally (STRADL) study:A depression-focused investigation of Generation Scotland, using detailed clinical, cognitive, and neuroimaging assessments

Grant information: STRADL is supported by the Wellcome Trust through a Strategic Award (104036/Z/14/Z). GS:SFHS received core support from the CSO of the Scottish Government Health Directorates (CZD/16/6) and the Scottish Funding Council (HR03006). ADM is supported by Innovate UK, the European Commission, the Scottish Funding Council via the Scottish Imaging Network SINAPSE, and the CSO. HCW is supported by a JMAS SIM Fellowship from the Royal College of Physicians of Edinburgh, by an ESAT College Fellowship from the University of Edinburgh, and has received previous funding from the Sackler Trust. LR has previously received financial support from Pfizer (formerly Wyeth) in relation to imaging studies of people with schizophrenia and bipolar disorder. JDH is supported by the MRC. DJM is an NRS Clinician, funded by the CSO. RMR is supported by the British Heart Foundation. ISP-V and MRM are supported by the NIHR Biomedical Research Centre at the University Hospitals Bristol NHS Foundation Trust and the University of Bristol. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health; and MRM is also supported by the MRC MC_UU_12013/6). JMW is supported by MRC UK Dementia Research Institute and MRC Centre and project grants, EPSRC, Fondation Leducq, Stroke Association, British Heart Foundation, Alzheimer Society, and the European Union H2020 PHC-03-15 SVDs@Target grant agreement (666881). DJP is supported by Wellcome Trust Longitudinal Population Study funding (216767/Z/19/Z) the Eva Lester bequest to the University of Edinburgh. AMM is additionally supported by the MRC (MC_PC_17209, MC_PC_MR/R01910X/1, MR/S035818/1), The Wellcome Trust (216767/Z/19/Z ), The Sackler Trust, and has previously received research funding from Pfizer, Eli Lilly, and Janssen. Both AMM and IJD are members of The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (MR/K026992/1); funding from the BBSRC and MRC is gratefully acknowledged. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewedPublisher PD

Phosphorylation of Mouse Immunity-Related GTPase (IRG) Resistance Proteins Is an Evasion Strategy for Virulent Toxoplasma gondii

GTPases of the mouse IRG protein family, mediators of resistance against Toxoplasma gondii in the mouse, are inactivated by a polymorphic kinase of the parasite, resulting in enhanced parasite virulence

Computation of Conformational Coupling in Allosteric Proteins

In allosteric regulation, an effector molecule binding a protein at one site induces conformational changes, which alter structure and function at a distant active site. Two key challenges in the computational modeling of allostery are the prediction of the structure of one allosteric state starting from the structure of the other, and elucidating the mechanisms underlying the conformational coupling of the effector and active sites. Here we approach these two challenges using the Rosetta high-resolution structure prediction methodology. We find that the method can recapitulate the relaxation of effector-bound forms of single domain allosteric proteins into the corresponding ligand-free states, particularly when sampling is focused on regions known to change conformation most significantly. Analysis of the coupling between contacting pairs of residues in large ensembles of conformations spread throughout the landscape between and around the two allosteric states suggests that the transitions are built up from blocks of tightly coupled interacting sets of residues that are more loosely coupled to one another