1,012 research outputs found

    Uncertainty, co-ordination and path dependence

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    Author's pre-print draft dated August 25, 2006. Final version published by Elsevier; available online at http://www.sciencedirect.com/Our objective is to assess whether dynamics hinder or assist co-ordination in a game with strategic complementarities. We study two dynamic aspects: different agents make decisions at different points in time; and extra information about a payoff-relevant state of nature becomes available over time. We find that the dynamic resolution of information matters most for uniqueness of equilibrium. This is demonstrated by showing that the condition for uniqueness is weaker when learning occurs. We also analyse how successfully agents co-ordinate when there is a unique equilibrium. Finally, we show that path dependence occurs: the order in which signals arrive matters, as well as the total amount of information received

    Exploring structural and electronic effects in three isomers of tris{bis(trifluoromethyl)phenyl}borane: Towards the combined electrochemical-frustrated Lewis pair activation of H2

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    Three structural isomers of tris{bis(trifluoromethyl)phenyl}borane have been studied as the acidic com- ponent of frustrated Lewis pairs. While the 3,5-substituted isomer is already known to heterolytically cleave H2 to generate a bridging-hydride; ortho-substituents in the 2,4- and 2,5-isomers quench such reactivity through electron donation into the vacant boron pz orbital and steric blocking of the boron centre; as shown by electrochemical, structural and computational studies. Electrochemical studies of the corresponding borohydrides identify that the two-electron oxidation of terminal-hydrides occurs at more positive potentials than observed for [HB(C6F5)3]−, while the bridging-hydride oxidizes at a higher poten- tial still, comparable to that of free H2

    Novel B(Ar')2(Ar'') hetero-tri(aryl)boranes: a systematic study of Lewis acidity

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    A series of homo- and hetero-tri(aryl)boranes incorporating pentafluorophenyl, 3,5-bis(trifluoromethyl)phenyl, and pentachlorophenyl groups, four of which are novel species, have been studied as the acidic component of frustrated Lewis pairs for the heterolytic cleavage of H2. Under mild conditions eight of these will cleave H2; the rate of cleavage depending on both the electrophilicity of the borane and the steric bulk around the boron atom. Electrochemical studies allow comparisons of the electrophilicity with spectroscopic measurements of Lewis acidity for different series of boranes. Discrepancies in the correlation between these two types of measurements, combined with structural characterisation of each borane, reveal that the twist of the aryl rings with respect to the boron-centred trigonal plane is significant from both a steric and electronic perspective, and is an important consideration in the design of tri(aryl)boranes as Lewis acids

    Merger policy, entry, and entrepreneurship

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    We assess the impact of merger policy on entry and entrepreneurship. When faced with uncertainty about its prospects, and foreseeing that it may wish to leave the market should profitability prove poor, a rational entrant considers possible exit routes. Horizontal merger reduces competition post-merger which, all else being equal, lowers welfare; but merger also provides a valuable exit route. By facilitating exit and thus raising the value of entry, more lenient merger policy may stimulate entry sufficiently that welfare is increased overall. We calculate the optimal merger policy in the form of a low, but positive, profitability threshold below which merger is permitted despite the adverse impact on post-merger competition. This may be viewed as an extension of the “failing firm defence” to include ailing, low profitability firms as well as imminently failing ones. Merger policy is compared with an entry subsidy, and the implications of strategic firm behaviour for the choice of merger policy are also examined

    Mental health support across the sight loss pathway: a qualitative exploration of eye care patients, optometrists, and ECLOs

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    BACKGROUND: The process of becoming visually impaired or blind is undoubtedly a highly emotional experience, requiring practical and psychological support. Information on mental health support provision in the UK across the sight-loss pathway, however, is largely unknown, especially amongst healthcare practitioners that are often sought after for advice: the referring optometrist and eye clinic liaison officer (ECLO). This study aims to ascertain the perceived accessibility and quality of mental health support across the sight-loss pathway. METHODS: Semi-structured individual interviews were conducted with patients with a diagnosed eye condition who had received care from a hospital eye service, referring optometrists, and ECLOs. Following interview transcription, results were synthesised in a narrative analysis. RESULTS: A total of 28 participants were included in the analysis, of which 17 were participants with various eye conditions, five were referring optometrists, and five were ECLOs. After analysis, three broad themes emerged: (1) The emotional trauma of diagnosis (2) Availability of mental health support; (3) The point where mental health support is most needed across the sight-loss pathway. Several patients reporting that they had received no offer of support nor were they signposted to any possible sources. Referring optometrists and ECLO’s agreed. CONCLUSION: It is important that referring optometrists are aware of the need for mental health support services and can signpost to local support services including the third sector anytime during the referral process. Future large-scale, UK-wide research into referral practice and signposting for mental health support for patients is warranted, to identify how services can be improved in order to ensure that the wellbeing of patients is maintaine

    Assessing worst case scenarios in movement demands derived from global positioning systems during international rugby union matches: Rolling averages versus fixed length epochs

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    The assessment of competitive movement demands in team sports has traditionally relied upon global positioning system (GPS) analyses presented as fixed-time epochs (e.g., 5–40 min). More recently, presenting game data as a rolling average has become prevalent due to concerns over a loss of sampling resolution associated with the windowing of data over fixed periods. Accordingly, this study compared rolling average (ROLL) and fixed-time (FIXED) epochs for quantifying the peak movement demands of international rugby union match-play as a function of playing position. Elite players from three different squads (n = 119) were monitored using 10 Hz GPS during 36 matches played in the 2014–2017 seasons. Players categorised broadly as forwards and backs, and then by positional sub-group (FR: front row, SR: second row, BR: back row, HB: half back, MF: midfield, B3: back three) were monitored during match-play for peak values of high-speed running (>5 m·s-1; HSR) and relative distance covered (m·min-1) over 60–300 s using two types of sample-epoch (ROLL, FIXED). Irrespective of the method used, as the epoch length increased, values for the intensity of running actions decreased (e.g., For the backs using the ROLL method, distance covered decreased from 177.4 ± 20.6 m·min-1 in the 60 s epoch to 107.5 ± 13.3 m·min-1 for the 300 s epoch). For the team as a whole, and irrespective of position, estimates of fixed effects indicated significant between-method differences across all time-points for both relative distance covered and HSR. Movement demands were underestimated consistently by FIXED versus ROLL with differences being most pronounced using 60 s epochs (95% CI HSR: -6.05 to -4.70 m·min-1, 95% CI distance: -18.45 to -16.43 m·min-1). For all HSR time epochs except one, all backs groups increased more (p < 0.01) from FIXED to ROLL than the forward groups. Linear mixed modelling of ROLL data highlighted that for HSR (except 60 s epoch), SR was the only group not significantly different to FR. For relative distance covered all other position groups were greater than the FR (p < 0.05). The FIXED method underestimated both relative distance (~11%) and HSR values (up to ~20%) compared to the ROLL method. These differences were exaggerated for the HSR variable in the backs position who covered the greatest HSR distance; highlighting important consideration for those implementing the FIXED method of analysis. The data provides coaches with a worst-case scenario reference on the running demands required for periods of 60–300 s in length. This information offers novel insight into game demands and can be used to inform the design of training games to increase specificity of preparation for the most demanding phases of matches

    Evidence for local and international spread of Mycobacterium avium subspecies paratuberculosis through whole genome sequencing of isolates from the island of Ireland

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    Publication history: Accepted - 1 April 2022; Published online - 5 April 2022We describe application of whole genome sequencing (WGS) to a collection of 197 Mycobacterium avium subsp paratuberculosis (MAP) isolates gathered from 122 cattle herds across 27 counties of the island of Ireland. We compare WGS to MAP diversity quantified using mycobacterial interspersed random unit – variable number tandem repeats (MIRU-VNTR). While MIRU-VNTR showed only two major types, WGS could split the 197 isolates into eight major groups. We also found six isolates corresponding to INMV 13, a novel MIRU-VNTR type for Ireland. Evidence for dispersal of MAP across Ireland via cattle movement could be discerned from the data, with mixed infections present in several herds. Furthermore, comparisons of MAP WGS data from Ireland to data from Great Britain and continental Europe revealed many instances of close genetic similarity and hence evidence for international transmission of infection. BEAST MASCOT structured coalescent analyses, with relaxed and strict molecular clocks, estimated the substitution rate to be 0.10–0.13 SNPs/site/year and disclosed greater transitions per lineage per year from Europe to Ireland, indicating transmission into Ireland. Our work therefore reveals new insight into the seeding of MAP infection across Ireland, highlighting how WGS can inform policy formulation to ultimately control MAP transmission at local, national and international scales.We acknowledge funding from the Department of Agriculture, Food and Marine awards 15/S/651 (‘NexusMAP’) and 2019R404 (’BTBGe- nIE’)
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