Solvent Azeotropes in Art Conservation

Solvent mixtures are often fine-tuned by art conservators for the difficult tasks of safely removing yellowed varnishes and obfuscating dirt from oil paintings. These two goals are often loosely termed “picture cleaning.” Concern has been raised over the impact of differential evaporation rates for solvents in the cleaning mixture. Differential evaporation can lead to changes in the mixture’s potency over time and potentially lead to solvent mixtures on the surface of the artwork having solubility characteristics deleterious to artists’ oil paints. Azeotropic mixtures of solvents have been proposed as an alternative for maintaining consistent solvent composition. Azeotropes are specific mixtures of two or more solvents that behave as a single solvent and maintain a constant composition at their boiling point. The azeotropes that have appeared in the art conservation literature are taken from tables of azeotropic compositions in the CRC Handbook given at their boiling point. This research examines whether these solvent blends, in particular a hexane/isopropanol combination found to be an effective cleaner in the treatment of painted royal sleighs at the Palace of Versailles, in fact behave azeotropically under room temperature evaporation conditions. For the first time, the actual evaporation behavior of this purported azeotropic mixture will be explored in depth. A range of hexane/isopropanol mixtures around the boiling point azeotrope composition have been assessed for their room temperature vapor pressure and evaporation weight loss kinetics. Aliquots of the evaporating solutions are also being analyzed chemically using gas chromatography of both the liquid phase and the vapor phase in the headspace. This research aims to provide conservators information on the evaporation of purportedly azeotropic solvent blends and to suggest new approaches to the cleaning of oil paintings

Does habitat stability structure intraspecific genetic diversity? It’s complicated...

Regional phylogeographic studies have long been conducted in the southeastern United States for a variety of species. With some exceptions, many of these studies focus on single species or single clades of organisms, and those considering multiple species tend to focus on deep historical breaks causing differentiation. However, in many species more recent factors may be influencing genetic diversity. To understand the roles of historic and contemporary processes in structuring genetic diversity, we reanalyzed existing genetic data from Southeast of North America using approaches gleaned from phylogeographic and landscape genetic literature that were implemented across species including AMOVAs, PCoAs, Species Distribution Modelling, and tests of isolation by distance, environment, and habitat instability. Genetic variance was significantly partitioned by ecoregions, watersheds, and across phylogeographic breaks in the majority of species. Similarly, genetic variation was significantly associated with some combination of geographic or environmental distance or habitat instability in most species. Patterns of genetic variation were largely idiosyncratic across species. While habitat instability over time is significantly correlated with genetic diversity in some species, it appears generally less important than isolation by geographic or environmental distance. Our results suggest that many factors, both historical and contemporary, impact genetic diversity within a species, and more so, that these patterns aren’t always similar in closely related species. This supports the importance of species- specific factors and cautions against assumptions that closely related species will respond to historical and contemporary forces in similar ways

Multicomponent frailty assessment tools for older people with psychiatric disorders: a systematic review

Objective: To review evidence evaluating the use of multi-component frailty assessment tools in assessing frailty in older adults with psychiatric disorders. Methods: A systematic literature review was conducted to identify all multi-component frailty assessment tools (i.e. a tool that assesses ≥2 indicators of frailty). The items of each frailty assessment tool were compared to DSM-5 diagnostic criteria for psychiatric disorders to assess construct overlap. Studies conducted in community, inpatient and outpatient clinical settings were considered for inclusion. Participants: Adults aged ≥60 years old. Results: 5,639 studies in total were identified following the removal of duplicates; 97 of which were included for review. Of the 48 multi-component frailty assessment tools identified, no tool had been developed for, or validated in, older adult populations with psychiatric disorder. 24/48 frailty assessment tools contained a psychological assessment domain, with 18/48 tools using presence of depressed mood and/or anxiety as a frailty indicator. Common areas of construct overlap in frailty assessment tools and DSM-5 diagnostic criteria included weight loss (29/48) and fatigue (21/48). Conclusions: Significant construct overlap exists between the indicators of frailty as conceptualised in existing frailty assessment tools and DSM-5 diagnostic criteria for common psychiatric disorders, including Major Depressive Episode and Generalised Anxiety Disorder, which has the potential to confound frailty assessment results. Further research is necessary to establish a reliable and valid tool to assess frailty in this population

Prospectus, April 20, 2005

https://spark.parkland.edu/prospectus_2005/1010/thumbnail.jp

A High-Resolution Radio Continuum Study Of The Dwarf Irregular Galaxy IC 10

We present high-resolution e–MERLIN radio continuum maps of the Dwarf Irregular galaxy IC 10 at 1.5 GHz and 5 GHz. We detect 11 compact sources at 1.5 GHz, 5 of which have complementary detections at 5 GHz. We classify 3 extended sources as compact HII regions within IC 10, 5 sources as contaminating background galaxies and identify 3 sources which require additional observa- tions to classify. We do not expect that any of these 3 sources are Supernova Remnants as they will likely be resolved out at the assumed distance of IC 10 (0.7 Mpc). We correct integrated flux densities of IC 10 from the literature for contamination by unrelated background sources and ob- tain updated flux density measurements of 354 ± 11 mJy at 1.5 GHz and 199 ± 9 mJy at 4.85 GHz. The background contamination does not contribute significantly to the overall radio emission from IC 10, so previous analysis concerning its integrated radio properties remain valid

The transiting multi-planet system HD3167: a 5.7 MEarth Super-Earth and a 8.3 MEarth mini-Neptune

HD3167 is a bright (V=8.9 mag) K0V star observed by the NASA's K2 space mission during its Campaign 8. It has been recently found to host two small transiting planets, namely, HD3167b, an ultra short period (0.96 d) super-Earth, and HD3167c, a mini-Neptune on a relatively long-period orbit (29.85 d). Here we present an intensive radial velocity follow-up of HD3167 performed with the FIES@NOT, [email protected], and HARPS-N@TNG spectrographs. We revise the system parameters and determine radii, masses, and densities of the two transiting planets by combining the K2 photometry with our spectroscopic data. With a mass of 5.69+/-0.44 MEarth, radius of 1.574+/-0.054 REarth, and mean density of 8.00(+1.0)(-0.98) g/cm^3, HD3167b joins the small group of ultra-short period planets known to have a rocky terrestrial composition. HD3167c has a mass of 8.33 (+1.79)(-1.85) MEarth and a radius of 2.740(+0.106)(-0.100) REarth, yielding a mean density of 2.21(+0.56)(-0.53) g/cm^3, indicative of a planet with a composition comprising a solid core surrounded by a thick atmospheric envelope. The rather large pressure scale height (about 350 km) and the brightness of the host star make HD3167c an ideal target for atmospheric characterization via transmission spectroscopy across a broad range of wavelengths. We found evidence of additional signals in the radial velocity measurements but the currently available data set does not allow us to draw any firm conclusion on the origin of the observed variation.Comment: 18 pages, 11 figures, 5 table

Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog With Measured Completeness and Reliability Based on Data Release 25

We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching four years of Kepler time series photometry (Data Release 25, Q1-Q17). The catalog contains 8054 KOIs of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new and include two in multi-planet systems (KOI-82.06 and KOI-2926.05), and ten high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter which automatically vets the DR25 Threshold Crossing Events (TCEs, Twicken et al. 2016). The Robovetter also vetted simulated data sets and measured how well it was able to separate TCEs caused by noise from those caused by low signal-to-noise transits. We discusses the Robovetter and the metrics it uses to sort TCEs. For orbital periods less than 100 days the Robovetter completeness (the fraction of simulated transits that are determined to be planet candidates) across all observed stars is greater than 85%. For the same period range, the catalog reliability (the fraction of candidates that are not due to instrumental or stellar noise) is greater than 98%. However, for low signal-to-noise candidates between 200 and 500 days around FGK dwarf stars, the Robovetter is 76.7% complete and the catalog is 50.5% reliable. The KOI catalog, the transit fits and all of the simulated data used to characterize this catalog are available at the NASA Exoplanet Archive.Comment: 61 pages, 23 Figures, 9 Tables, Accepted to The Astrophysical Journal Supplement Serie

Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis

Background More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+)to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.Methods In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.Findings We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+.After 5\u20138 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0\ub717, 95% CI 0\ub711\u20130\ub725) among girls aged 13\u201319 years, and decreased significantly by 66% (RR 0\ub734, 95% CI 0\ub723\u20130\ub749) among women aged 20\u201324 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0\ub746, 95% CI 0\ub733\u20130\ub766) among girls aged 13\u201319 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0\ub733, 95% CI 0\ub724\u20130\ub746) among girls aged 15\u201319 years, decreased significantly by 54% (RR 0\ub746, 95% CI 0.36\u20130.60) among women aged 20\u201324 years, and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub753\u20130\ub789) among women aged 25\u201329 years. Among boys aged 15\u201319 years anogenital wart diagnoses decreased significantly by 48% (RR 0\ub752, 95% CI 0\ub737\u20130\ub775) and among men aged 20\u201324 years they decreased significantly by 32% (RR 0\ub768, 95% CI 0\ub747\u20130\ub798). After 5\u20139 years of vaccination, CIN2+ decreased significantly by 51% (RR 0\ub749, 95% CI 0\ub742\u20130\ub758) among screened girls aged 15\u201319 years and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub757\u20130\ub784) among women aged 20\u201324 years.Interpretation This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects