"State Dependence and Long Term Site Capital in a Random Utility Model of Recreation Demand"

Conventional discrete choice Random Utility Maximization (RUM) models of recreation demand ignore the influence of knowledge, or site capital, gained over past trips on current site choice, despite its obvious impact. We develop a partially dynamic RUM model that incorporates a measure of site capital as an explanatory variable in an effort to address this shortcoming. To avoid the endogeneity of past and current trip choices, we estimate an auxiliary instrumental variable regression to purge site capital of its correlation with the error terms in current site utility. Our instrumental variable regression gives a fitted value ranging between 0 and 1 for each alternative for each person – a prediction of whether or not a person visited a site. Results suggest that the presence of accumulated site capital is an important predictor of current trips, and that failure to account for site capital will likely lead to underestimates of potential welfare effects.Random Utility Model; State Dependence; Non-Market Valuation

FAMILIAR AND FAVORITE SITES IN A RANDOM UTILITY MODEL OF BEACH RECREATION

We estimate a random utility model of recreation demand accounting for choice set familiarity and favorite sites. Our approach differs from existing approaches by retaining all sites in estimating the parameters of site utility. Familiar and unfamiliar sites are specified with different utility functions. Favored sites are assumed to have higher utility than nonfavored sites in estimation.Resource /Energy Economics and Policy,

Diving Demand for Large Ship Artificial Reefs

Using data drawn from a web-based travel cost survey, we jointly model revealed and stated preference trip count data in an attempt to estimate the recreational use value from diving the intentionally sunk USS Oriskany. Respondents were asked to report their: (i) actual trips from the previous year, (ii) anticipated trips in the next year, and (iii) anticipated trips next year assuming a second diveable vessel (a Spruance class destroyer) is sunk in the same vicinity. Results from several different model specifications indicate average per-person, per-trip use values range from $480 to$750. The “bundling†of a second vessel in the area of the Oriskany to create a multiple-ship artificial reef area adds between $220 and$1,160 per diver per year in value.Artificial reefs, diving, recreation demand, combined revealed and stated preferences, non-market valuation, Institutional and Behavioral Economics, Marketing, Productivity Analysis, Public Economics, Research Methods/ Statistical Methods, Q26, Q50,

Experience with the Hubble Space Telescope: 20 years of an archetype

The Hubble Space Telescope's mission is summarized, with special emphasis placed on the Space Telescope Science Institute's unique experience with Hubble's behavior as an astronomical telescope in the environment of low earth orbit for over two decades. Historical context and background are given, and the project's early scientific expectations are described. A general overview of the spacecraft is followed by a more detailed look at the optical design, both as intended and as built. Basic characteristics of the complete complement of science instruments are also summarized. Experience with the telescope on-orbit is reviewed, starting with the major initial problems, solutions, human servicing missions, and the associated expansion of the observatory's capabilities over this time. Specific attention is then given to understanding Hubble's optical quality and pointing/jitter performance, two fundamental characteristics of a telescope. Experience with-and the important mitigation of-radiation damage and contamination is also related. Beyond the telescope itself, the advances in data reduction, calibration, and observing techniques are briefly discussed, as well as the subsequent emergence of highly accessible high-level archival science products. Hubble's scientific impact concludes the discussion.Comment: Also found at http://www.stsci.edu/institute/org/telescopes/Reports/LalloOE2012.pd

Gridmapping the northern plains of Mars: Geomorphological, Radar and Water-Equivalent Hydrogen results from Arcadia Plantia

A project of mapping ice-related landforms was undertaken to understand the role of sub-surface ice in the northern plains. This work is the first continuous regional mapping from CTX (“ConTeXt Camera”, 6 m/pixel; Malin et al., 2007) imagery in Arcadia Planitia along a strip 300 km across stretching from 30°N to 80°N centred on the 170° West line of longitude. The distribution and morphotypes of these landforms were used to understand the permafrost cryolithology. The mantled and textured signatures occur almost ubiquitously between 35° N and 78° N and have a positive spatial correlation with inferred ice stability based on thermal modelling, neutron spectroscopy and radar data. The degradational features into the LDM (Latitude Dependent Mantle) include pits, scallops and 100 m polygons and provide supporting evidence for sub-surface ice and volatile loss between 35-70° N in Arcadia with the mantle between 70-78° N appearing much more intact. Pitted terrain appears to be much more pervasive in Arcadia than in Acidalia and Utopia suggesting that the Arcadia study area had more wide-spread near-surface sub-surface ice, and thus was more susceptible to pitting, or that the ice was less well-buried by sediments. Correlations with ice stability models suggest that lack of pits north of 65-70° N could indicate a relatively young age (~1Ma), however this could also be explained through regional variations in degradation rates. The deposition of the LDM is consistent with an airfall hypothesis however there appears to be substantial evidence for fluvial processes in southern Arcadia with older, underlying processes being equally dominant with the LDM and degradation thereof in shaping the landscape

Dimensions of Misinformation About the HPV Vaccine on Instagram: Content and Network Analysis of Social Media Characteristics.

BACKGROUND: The human papillomavirus (HPV) vaccine is a major advancement in cancer prevention and this primary prevention tool has the potential to reduce and eliminate HPV-associated cancers; however, the safety and efficacy of vaccines in general and the HPV vaccine specifically have come under attack, particularly through the spread of misinformation on social media. The popular social media platform Instagram represents a significant source of exposure to health (mis)information; 1 in 3 US adults use Instagram. OBJECTIVE: The objective of this analysis was to characterize pro- and anti-HPV vaccine networks on Instagram, and to describe misinformation within the anti-HPV vaccine network. METHODS: From April 2018 to December 2018, we collected publicly available English-language Instagram posts containing hashtags #HPV, #HPVVaccine, or #Gardasil using Netlytic software (n=16,607). We randomly selected 10% of the sample and content analyzed relevant posts (n=580) for text, image, and social media features as well as holistic attributes (eg, sentiments, personal stories). Among antivaccine posts, we organized elements of misinformation within four broad dimensions: 1) misinformation theoretical domains, 2) vaccine debate topics, 3) evidence base, and 4) health beliefs. We conducted univariate, bivariate, and network analyses on the subsample of posts to quantify the role and position of individual posts in the network. RESULTS: Compared to provaccine posts (324/580, 55.9%), antivaccine posts (256/580, 44.1%) were more likely to originate from individuals (64.1% antivaccine vs 25.0% provaccine; P\u3c.001) and include personal narratives (37.1% vs 25.6%; P=.003). In the antivaccine network, core misinformation characteristics included mentioning #Gardasil, purporting to reveal a lie (ie, concealment), conspiracy theories, unsubstantiated claims, and risk of vaccine injury. Information/resource posts clustered around misinformation domains including falsification, nanopublications, and vaccine-preventable disease, whereas personal narrative posts clustered around different domains of misinformation, including concealment, injury, and conspiracy theories. The most liked post (6634 likes) in our full subsample was a positive personal narrative post, created by a non-health individual; the most liked post (5604 likes) in our antivaccine subsample was an informational post created by a health individual. CONCLUSIONS: Identifying characteristics of misinformation related to HPV vaccine on social media will inform targeted interventions (eg, network opinion leaders) and help sow corrective information and stories tailored to different falsehoods

How penalizing substance use in pregnancy affects treatment and research: A qualitative examination of researchers\u27 perspectives

INTRODUCTION: Laws regulating substance use in pregnancy are changing and may have unintended consequences on scientific efforts to address the opioid epidemic. Yet, how these laws affect care and research is poorly understood. METHODS: We conducted semi-structured qualitative interviews using purposive and snowball sampling of researchers who have engaged pregnant people experiencing substance use. We explored views on laws governing substance use in pregnancy and legal reform possibilities. Interviews were double coded. Data were examined using thematic analysis. RESULTS: We interviewed 22 researchers (response rate: 71 per cent) and identified four themes: (i) harms of punitive laws, (ii) negative legal impacts on research, (iii) proposals for legal reform, and (iv) activism over time. DISCUSSION: Researchers view laws penalizing substance use during pregnancy as failing to treat addiction as a disease and harming pregnant people and families. Respondents routinely made scientific compromises to protect participants. While some have successfully advocated for legal reform, ongoing advocacy is needed. CONCLUSION: Adverse impacts from criminalizing substance use during pregnancy extend to research on this common and stigmatized problem. Rather than penalizing substance use in pregnancy, laws should approach addiction as a medical issue and support scientific efforts to improve outcomes for affected families

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

ACKNOWLEDGEMENTS Review and editing: S.R. Brown, Professor of Surgery, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK. Email [email protected]. Patient summary: R.G. Arnott, Retired Professor, Patient Liaison Group, Association of Coloproctology of Great Britain and Ireland, Royal College of Surgeons of England, London, UK. Email [email protected]. Delphi review: C.P. Macklin. BMedSci BM BS FRCS DM, Consultant Colorectal Surgeon, Mid Yorkshire Hospitals, UK. Email [email protected] reviewedPublisher PD

Living with ulcerative colitis study (LUCY) in England: A retrospective study evaluating healthcare resource utilisation and direct healthcare costs of postoperative care in ulcerative colitis

© 2020 The Authors. Published by BMJ. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: http://dx.doi.org/10.1136/bmjgast-2020-000456Objective Ulcerative colitis (UC) is a lifelong, relapsing-remitting disease. Patients non-responsive to pharmacological treatment may require a colectomy. We estimated pre-colectomy and post-colectomy healthcare resource utilisation (HCRU) and costs in England. Design/Method A retrospective, longitudinal cohort study indexing adult patients with UC undergoing colectomy (2009-2015), using linked Clinical Practice Research Datalink/Hospital Episode Statistics data, was conducted. HCRU, healthcare costs and pharmacological treatments were evaluated during 12 months prior to and including colectomy (baseline) and 24 months post-colectomy (follow-up; F-U), comparing baseline/F-U, emergency/elective colectomy and subtotal/full colectomy using descriptive statistics and paired/unpaired tests. Results 249 patients from 26 165 identified were analysed including 145 (58%) elective and 184 (74%) full colectomies. Number/cost of general practitioner consultations increased post-colectomy (p<0.001), and then decreased at 13-24 months (p<0.05). From baseline to F-U, the number of outpatient visits, number/cost of hospitalisations and total direct healthcare costs decreased (all p<0.01). Postoperative HCRU was similar between elective and emergency colectomies, except for the costs of colectomy-related hospitalisations and medication, which were lower in the elective group (p<0.05). Postoperative costs were higher for subtotal versus full colectomies (p<0.001). At 1-12 month F-U, 30%, 19% and 5% of patients received aminosalicylates, steroids and immunosuppressants, respectively. Conclusion HCRU/costs increased for primary care in the first year post-colectomy but decreased for secondary care, and varied according to the colectomy type. Ongoing and potentially unnecessary pharmacological therapy was seen in up to 30% of patients. These findings can inform patients and decision-makers of potential benefits and burdens of colectomy in UC.The study was funded by Pfizer Inc.Published versio

Spitzer Space Telescope observations of the Carina Nebula: The steady march of feedback-driven star formation

We report the first results of imaging the Carina Nebula with Spitzer/IRAC, providing a catalog of point sources and YSOs based on SED fits. We discuss several aspects of the extended emission, including dust pillars that result when a clumpy molecular cloud is shredded by massive star feedback. There are few "extended green objects" (EGOs) normally taken as signposts of outflow activity, and none of the HH jets detected optically are seen as EGOs. A population of "extended red objects" tends to be found around OB stars, some with clear bow-shocks. These are dusty shocks where stellar winds collide with flows off nearby clouds. Finally, the relative distributions of O stars and subclusters of YSOs as compared to dust pillars shows that while some YSOs are located within pillars, many more stars and YSOs reside just outside pillar heads. We suggest that pillars are transient phenomena, part of a continuous outwardly propagating wave of star formation driven by massive star feedback. As pillars are destroyed, they leave newly formed stars in their wake, which are then subsumed into the young OB association. Altogether, the current generation of YSOs shows no strong deviation from a normal IMF. The number of YSOs suggests a roughly constant star-formation rate over the past 3Myr, implying that star formation in pillars constitutes an important mechanism to construct unbound OB associations. Accelerated pillars may give birth to O-type stars that, after several Myr, could appear to have formed in isolation.Comment: 25 pages, 15 figures, MNRAS accepte