The Housing Price Bubble In A Suburban Georgia Setting: Using The Hedonic Pricing Model In The New South

This study applies a hedonic pricing model to the rapidly developing suburban housing market adjacent to the Savannah Historic Landmark District in the downtown area of Savannah, Georgia. Using OLS estimation, the hedonic pricing model yields results clearly tracing out the magnitude of the time-related housing price premium in the suburban market analyzed for the years from 2005 to 2010. The results also control for internal and external housing characteristics that are capitalized into the real sales prices of the housing transactions analyzed

Medical students’ challenges and suggestions regarding research training: a synthesis of comments from a cross-sectional survey

Background: We previously reported on a cross-sectional study of students from the Michael G. DeGroote School of Medicine at McMaster University that found most respondents wanted more opportunities to participate in research. Students provided additional comments that we synthesized to enrich the findings of our quantitative analysis.   Methods: From our previously administered 13-item, online questionnaire, run across three campuses in Ontario, Canada, 498 of 618 medical students completed our survey and 360 (72%) provided optional written comments, which we synthesized using thematic analysis in this current study.  Results: Major themes that emerged were: (1) Active student participation to identify research opportunities and interested mentors are needed; (2) Types of research involvement; (3) Uncertainty whether research training translates into useable skills; (4) Desire for a formalized research curriculum and centralization of research opportunities across campuses.  Conclusion: Programs should stress to interested students the importance of actively looking for research opportunities and consider both large and small-group educational sessions

Statistical Properties of Gamma-Ray Burst Polarization

The emission mechanism and the origin and structure of magnetic fields in gamma-ray burst (GRB) jets are among the most important open questions concerning the nature of the central engine of GRBs. In spite of extensive observational efforts, these questions remain to be answered and are difficult or even impossible to infer with the spectral and lightcurve information currently collected. Polarization measurements will lead to unambiguous answers to several of these questions. Recent developments in X-ray and gamma-ray polarimetry techniques have demonstrated a significant increase in sensitivity enabling several new mission concepts, e.g. POET (Polarimeters for Energetic Transients), providing wide field of view and broadband polarimetry measurements. If launched, missions of this kind would finally provide definitive measurements of GRB polarizations. We perform Monte Carlo simulations to derive the distribution of GRB polarizations in three emission models; the synchrotron model with a globally ordered magnetic field (SO model), the synchrotron model with a locally random magnetic field (SR model), and the Compton drag model (CD model). The results show that POET, or other polarimeters with similar capabilities, can constrain the GRB emission models by using the statistical properties of GRB polarizations. In particular, the ratio of the number of GRBs for which the polarization degrees can be measured to the number of GRBs that are detected (N_m/N_d) and the distributions of the polarization degrees (Pi) can be used as the criteria. If N_m/N_d > 30% and Pi is clustered between 0.2 and 0.7, the SO model will be favored. If instead N_m/N_d < 15%, then the SR or CD model will be favored. If several events with Pi > 0.8 are observed, then the CD model will be favored.Comment: Replaced with accepted version in ApJ. A few minor changes done. References adde

Pharmacist and Data-driven Quality Improvement in Primary Care (P-DQIP):A qualitative study of anticipated implementation factors informed by the Theoretical Domains Framework

Objectives: The quality and safety of drug therapy in primary care are global concerns. The Pharmacist and Data driven Quality Improvement in Primary care (P-DQIP) intervention aims to improve prescribing safety via an informatics tool which facilitates proactive management of drug therapy risks (DTRs) by health-board employed pharmacists with established roles in general practices. Study objectives were (1) to identify and prioritise factors that could influence P-DQIP implementation from the perspective of practice pharmacists, and (2) to identify potentially effective, acceptable and feasible strategies to support P-DQIP implementation. Design: Semi-structured face-to-face interviews using a Theoretical Domains Framework (TDF) informed topic guide. The framework method was used for data analysis. Identified implementation factors were prioritised for intervention based on research team consensus. Candidate intervention functions, behaviour change techniques (BCTs) and policies targeting these were identified from the Behaviour Change Wheel. The final intervention content and modes of delivery were agreed with local senior pharmacists. Setting: General practices from three Health and Social Care Partnerships (HSCPs) in NHS Tayside. Participants: 14 NHS employed practice pharmacists. Results: Identified implementation factors were linked to thirteen theoretical domains (all except intentions) and six (skill, memory/attention/decision-making, behavioural regulation, reinforcement, environmental context/resources, social influences) were prioritised. Three intervention functions (training, enablement, and environmental restructuring) were relevant and were served by two policy categories (guidelines, communication/marketing) and eight BCTs (Instructions on how to perform a behaviour, problem solving, action planning, prompt/cues, goal setting, self-monitoring, feedback, restructuring the social environment). Intervention components encompass an informatics tool, written educational material, a workshop for pharmacists, promotional activities, and small financial incentives. Conclusions: This study explored pharmacists’ perceptions of implementation factors which could influence management of DTRs in general practices to inform implementation of P-DQIP, which will initially be implemented in one Scottish health board with parallel evaluation of effectiveness and implementation

The Total Synthesis of Glycolipids from Streptococcus pneumoniae and a Re-evaluation of Their Immunological Activity**

Invariant natural killer (iNK) T cells, Type I iNKTs, are responsible for the production of pro-inflammatory cytokines which induce a systemic immune response. They are distinctive in possessing an semi-invariant T-cell receptor that recognizes glycolipid antigens presented by CD1d, a protein closely related to the class I major histocompatibility complex, conserved across multiple mammalian species in a class of proteins well-renowned for their high degree of polymorphism. This receptor\u27s first potent identified antigen is the α-galactosylceramide, KRN7000, a synthetic glycosphingolipid closely related to those isolated from bacteria that were found on a Japanese marine sponge. A corresponding terrestrial antigen remained unidentified until two specific diacylglycerol-containing glycolipids, reported to activate iNKT cells, were isolated from Streptococcus pneumoniae. We report the total synthesis and immunological re-evaluation of these two glycolipids. The compounds are unable to meaningfully activate iNKT cells. Computational modelling shows that these ligands, while being capable of interacting with the CD1d receptor, create a different surface for the binary complex that makes formation of the ternary complex with the iNKT T-cell receptor difficult. Together these results suggest that the reported activity might have been due to an impurity in the original isolated sample and highlights the importance of taking care when reporting biological activity from isolated natural products

GRB Polarimetry with POET

POET (Polarimeters for Energetic Transients) represents a concept for a Small Explorer (SMEX) satellite mission, whose principal scientific goal is to understand the structure of GRB sources through sensitive X‐ray and γ‐ray polarization measurements. The payload consists of two wide field‐of‐view (FoV) instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2–15 keV and a high energy polarimeter (Gamma‐Ray Polarimeter Experiment or GRAPE) that would measure polarization in the 60–500 keV energy range. The POET spacecraft provides a zenith‐pointed platform for maximizing the exposure to deep space. Spacecraft rotation provides a means of effectively dealing with any residual systematic effects in the polarization response. POET provides sufficient sensitivity and sky coverage to measure statistically significant polarization (for polarization levels in excess of 20%) for ∼80 GRBs in a two‐year mission. High energy polarization data would also be obtained for SGRs, solar flares, pulsars and other sources of astronomical interest

Mechanistic insights into chemical and photochemical transformations of bismuth vanadate photoanodes

Artificial photosynthesis relies on the availability of semiconductors that are chemically stable and can efficiently capture solar energy. Although metal oxide semiconductors have been investigated for their promise to resist oxidative attack, materials in this class can suffer from chemical and photochemical instability. Here we present a methodology for evaluating corrosion mechanisms and apply it to bismuth vanadate, a state-of-the-art photoanode. Analysis of changing morphology and composition under solar water splitting conditions reveals chemical instabilities that are not predicted from thermodynamic considerations of stable solid oxide phases, as represented by the Pourbaix diagram for the system. Computational modelling indicates that photoexcited charge carriers accumulated at the surface destabilize the lattice, and that self-passivation by formation of a chemically stable surface phase is kinetically hindered. Although chemical stability of metal oxides cannot be assumed, insight into corrosion mechanisms aids development of protection strategies and discovery of semiconductors with improved stability

First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole

We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of similar to 40 mu as, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions

Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope

The Event Horizon Telescope (EHT) has recently delivered the first resolved images of M87*, the supermassive black hole in the center of the M87 galaxy. These images were produced using 230 GHz observations performed in 2017 April. Additional observations are required to investigate the persistence of the primary image feature—a ring with azimuthal brightness asymmetry—and to quantify the image variability on event horizon scales. To address this need, we analyze M87* data collected with prototype EHT arrays in 2009, 2011, 2012, and 2013. While these observations do not contain enough information to produce images, they are sufficient to constrain simple geometric models. We develop a modeling approach based on the framework utilized for the 2017 EHT data analysis and validate our procedures using synthetic data. Applying the same approach to the observational data sets, we find the M87* morphology in 2009–2017 to be consistent with a persistent asymmetric ring of ~40 μas diameter. The position angle of the peak intensity varies in time. In particular, we find a significant difference between the position angle measured in 2013 and 2017. These variations are in broad agreement with predictions of a subset of general relativistic magnetohydrodynamic simulations. We show that quantifying the variability across multiple observational epochs has the potential to constrain the physical properties of the source, such as the accretion state or the black hole spin