Does Online Availability Increase Citations? Theory And Evidence From A Panel Of Economics And Business Journals

Does online availability boost citations? Using a panel of citations to economics and business journals, we show that the enormous effects found in previous studies were an artifact of their failure to control for article quality, disappearing once fixed effects are added as controls. The absence of aggregate effects masks heterogeneity across platforms: JSTOR has a uniquely large effect, boosting citations around 10%. We examine other sources of heterogeneity, including whether JSTOR disproportionately increases cites from developing countries or to ‘‘long-tail’’ articles. Our theoretical analysis informs the econometric specification and allows citation increases to be translated into welfare terms

Identifying the Effect of Open Access on Citations Using a Panel of Science Journals

An open‐access journal allows free online access to its articles, obtaining revenue from fees charged to submitting authors or from institutional support. Using panel data on science journals, we are able to circumvent problems plaguing previous studies of the impact of open access on citations. In contrast to the huge effects found in these previous studies, we find a more modest effect: moving from paid to open access increases cites by 8% on average in our sample. The benefit is concentrated among top‐ranked journals. In fact, open access causes a statistically significant reduction in cites to the bottom‐ranked journals in our sample, leading us to conjecture that open access may intensify competition among articles for readers\u27 attention, generating losers as well as winners

Zebra Mussels Affect Benthic Predator Foraging Success

The introduction of zebra mussels (Dreissena spp.) to North America has resulted in dramatic changes to the complexity of benthic habitats. Changes in habitat complexity may have profound effects on predator-prey interactions in aquatic communities. Increased habitat complexity may affect prey and predator dynamics by reducing encounter rates and foraging success. Zebra mussels form thick contiguous colonies on both hard and soft substrates. While the colonization of substrata by zebra mussels has generally resulted in an increase in both the abundance and diversity of benthic invertebrate communities, it is not well known how these changes affect the foraging efficiencies of predators that prey on benthic invertebrates. We examined the effect of zebra mussels on the foraging success of four benthic predators with diverse prey-detection modalities that commonly forage in soft substrates: slimy sculpin (Cottus cognatus), brown bullhead ( Ameirus nebulosus), log perch (Percina caprodes), and crayfish (Orconectes propinquus). We conducted laboratory experiments to assess the impact of zebra mussels on the foraging success of predators using a variety of prey species. We also examined habitat use by each predator over different time periods. Zebra mussel colonization of soft sediments significantly reduced the foraging efficiencies of all predators. However, the effect was dependent upon prey type. All four predators spent more time in zebra mussel habitat than in either gravel or bare sand. The overall effect of zebra mussels on benthic-feeding fishes is likely to involve a trade-off between the advantages of increased density of some prey types balanced against the reduction in foraging success resulting from potential refugia offered in the complex habitat created by zebra mussels

Negative Effect of Zebra Mussels on Foraging and Habitat Use by Lake Sturgeon (Acipenser fulvescens)

1. Lake sturgeon (Acipenser fulvescens) are threatened or endangered throughout much of their range. Juvenile sturgeon utilize sandy and silty habitats extensively during their growth. Invasive zebra mussels change the nature of sandy and silty habitats because they settle on and coat the habitat with the shells of living and dead individuals. The potential impacts of this increased habitat complexity on lake sturgeon is unknown. 2. Juvenile lake sturgeon habitat choice was assessed in laboratory experiments, and zebra mussel impact on the foraging success of juvenile lake sturgeon on three different prey species was measured. 3. Sturgeon foraging on chironomids was virtually eliminated by 95% zebra mussel cover of the sand floor of the foraging arena, and 50% cover reduced foraging significantly. Foraging on more mobile prey items (amphipods and isopods) was essentially eliminated by either 95% or 50% zebra mussel cover of the arena floor. In habitat choice experiments, sturgeon avoided the zebra-mussel- covered habitat more than 90% of the time. 4. This combination of zebra mussel avoidance and reduced foraging in the presence of zebra mussels may be detrimental to sturgeon restocking programmes utilizing smaller sturgeon in zebra-mussel-infested waterways

A Model of Academic Journal Quality with Applications to Open-Access Journals

Previous research modeled academic journals as platforms connecting authors with readers in a two-sided market. This research used the same basic framework also used to study telephony, credit cards, video game consoles, etc. In this paper, we focus on a key difference between the market for academic journals and these other markets: journals vary in terms of quality, where a journal's quality determined by the quality of the papers it publishes. We provide a simple model of journal quality. As an illustration of the value of the model, we use it to address issues that have arisen in the recent debate concerning whether, in the Internet age, journals should become 'open access' (freely available to readers, financed by author rather than subscriber fees). Among other issues, we examine (a) whether open-access journals would tend to publish more articles than traditional journals, moving further down the quality spectrum in order to boost revenue; (b) whether journal quality affects the profitability of adopting open access; and (c) whether submission fees or acceptance fees are better instruments to extract surplus from authors

Evaluation of a prototype tool for communicating body perception disturbances in complex regional pain syndrome

Patients with Complex Regional Pain Syndrome (CRPS) experience distressing changes in body perception. However representing body perception is a challenge. A digital media tool for communicating body perception disturbances was developed. A proof of concept study evaluating the acceptability of the application for patients to communicate their body perception is reported in this methods paper. Thirteen CRPS participants admitted to a 2-week inpatient rehabilitation program used the application in a consultation with a research nurse. Audio recordings were made of the process and a structured questionnaire was administered to capture experiences of using the tool. Participants produced powerful images of disturbances in their body perception. All reported the tool acceptable for communicating their body perception. Participants described the positive impact of now seeing an image they had previously only imagined and could now convey to others. The application has provided a novel way for communicating perceptions that are otherwise difficult to convey

Mental health in UK Biobank: development, implementation and results from an online questionnaire completed by 157 366 participants

Background UK Biobank is a well-characterised cohort of over 500 000 participants that offers unique opportunities to investigate multiple diseases and risk factors. Aims An online mental health questionnaire completed by UK Biobank participants was expected to expand the potential for research into mental disorders. Method An expert working group designed the questionnaire, using established measures where possible, and consulting with a patient group regarding acceptability. Case definitions were defined using operational criteria for lifetime depression, mania, anxiety disorder, psychotic-like experiences and self-harm, as well as current post-traumatic stress and alcohol use disorders. Results 157 366 completed online questionnaires were available by August 2017. Comparison of self-reported diagnosed mental disorder with a contemporary study shows a similar prevalence, despite respondents being of higher average socioeconomic status than the general population across a range of indicators. Thirty-five per cent (55 750) of participants had at least one defined syndrome, of which lifetime depression was the most common at 24% (37 434). There was extensive comorbidity among the syndromes. Mental disorders were associated with high neuroticism score, adverse life events and long-term illness; addiction and bipolar affective disorder in particular were associated with measures of deprivation. Conclusions The questionnaire represents a very large mental health survey in itself, and the results presented here show high face validity, although caution is needed owing to selection bias. Built into UK Biobank, these data intersect with other health data to offer unparalleled potential for crosscutting biomedical research involving mental health

A Model of Academic Journal Quality with Applications to Open-Access Journals

Previous research modeled academic journals as platforms connecting authors with readers in a two-sided market. This research used the same basic framework also used to study telephony, credit cards, video game consoles, etc. In this paper, we focus on a key difference between the market for academic journals and these other markets: journals vary in terms of quality, where a journal's quality determined by the quality of the papers it publishes. We provide a simple model of journal quality. As an illustration of the value of the model, we use it to address issues that have arisen in the recent debate concerning whether, in the Internet age, journals should become 'open access' (freely available to readers, financed by author rather than subscriber fees). Among other issues, we examine (a) whether open-access journals would tend to publish more articles than traditional journals, moving further down the quality spectrum in order to boost revenue; (b) whether journal quality affects the profitability of adopting open access; and (c) whether submission fees or acceptance fees are better instruments to extract surplus from authors

Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks

The large relative sizes of circumstellar and circumplanetary disks imply that they might be seen in eclipse in stellar light curves. We estimate that a survey of ~10^4 young (~10 Myr old) post-accretion pre-MS stars monitored for ~10 years should yield at least a few deep eclipses from circumplanetary disks and disks surrounding low mass companion stars. We present photometric and spectroscopic data for a pre-MS K5 star (1SWASP J140747.93-394542.6), a newly discovered ~0.9 Msun member of the ~16 Myr-old Upper Cen-Lup subgroup of Sco-Cen at a kinematic distance of 128 pc. SuperWASP and ASAS light curves for this star show a remarkably long, deep, and complex eclipse event centered on 29 April 2007. At least 5 multi-day dimming events of >0.5 mag are identified, with a >3.3 mag deep eclipse bracketed by two pairs of ~1 mag eclipses symmetrically occurring +-12 days and +-26 days before and after. Hence, significant dimming of the star was taking place on and off over at least a ~54 day period in 2007, and a strong >1 mag dimming event occurred over a ~12 day span. We place a firm lower limit on the period of 850 days (i.e. the orbital radius of the eclipser must be >1.7 AU and orbital velocity must be <22 km/s). The shape of the light curve is similar to the lop-sided eclipses of the Be star EE Cep. We suspect that this new star is being eclipsed by a low-mass object orbited by a dense inner disk, girded by at least 3 dusty rings of lower optical depth. Between these rings are at least two annuli of near-zero optical depth (i.e. gaps), possibly cleared out by planets or moons, depending on the nature of the secondary. For possible periods in the range 2.33-200 yr, the estimated total ring mass is ~8-0.4 Mmoon (if the rings have optical opacity similar to Saturn's rings), and the edge of the outermost detected ring has orbital radius ~0.4-0.09 AU.Comment: Astronomical Journal, in press, 13 figure

Plasma fibrinogen and risk of vascular recurrence after ischaemic stroke:An individual participant and summary-level data meta-analysis of 11 prospective studies

INTRODUCTION: Inflammation is an emerging target for secondary prevention after stroke and randomised trials of anti-inflammatory therapies are ongoing. Fibrinogen, a putative pro-inflammatory marker, is associated with first stroke, but its association with major adverse cardiovascular events (MACE) after stroke is unclear.MATERIALS AND METHODS: We did a systematic review investigating the association between fibrinogen and post-stroke vascular recurrence. Authors were invited to provide individual-participant data (IPD) and where available we did within-study multivariable analyses with adjustment for cardiovascular risk factors and medications. Adjusted summary-level data was extracted from published reports from studies that did not provide IPD. We pooled risk ratios (RR) by random-effects meta-analysis by comparing supra-median with sub-median fibrinogen levels and performed pre-specified subgroup analysis according to timing of phlebotomy after the index event.RESULTS: Eleven studies were included (14,002 patients, 42,800 follow-up years), of which seven provided IPD. Fibrinogen was associated with recurrent MACE on unadjusted (RR 1.35, 95% CI 1.17-1.57, supra-median vs sub-median) and adjusted models (RR 1.21, 95% CI 1.06-1.38). Fibrinogen was associated with recurrent stroke on univariate analysis (RR 1.19, 95% CI 1.03-1.39), but not after adjustment (RR 1.11, 95% CI 0.94-1.31). The association with recurrent MACE was consistently observed in patients with post-acute (⩾14 days) fibrinogen measures (RR 1.29, 95% CI 1.16-1.45), but not in those with early phlebotomy (&lt;14 days) (RR 0.98, 95% CI 0.82-1.18) ( P interaction  = 0.01). Similar associations were observed for recurrent stroke. DISCUSSION AND CONCLUSION: Fibrinogen was independently associated with recurrence after stroke, but the association was modified by timing of phlebotomy. Fibrinogen measurements might be useful to identify patients who are more likely to derive benefit from anti-inflammatory therapies after stroke.</p