A new in-situ method to estimate fish target strength reveals high variability in broadband measurements

Acknowledgements The authors thank the Greenland Institute of Natural Resources (GINR), the University of Aberdeen, and Marine Alliance for Science and Technology for Scotland (MASTS) for funding this study. MASTS is funded by the Scottish Funding Council (grant no. HR09011) and contributing institutions. Further, they thank GINR for providing access to their facilities.Peer reviewedPublisher PD

The moderating effect of debates on political attitudes

In theory, candidate debates can influence voters by providing information about candidates' quality and policy positions. However, there is limited evidence about whether and why debates influence voters in new democracies. We use a field experiment on parliamentary debates during Ghana's 2016 elections to show that debates improve voters' evaluations of candidates. Debates have the strongest effect on partisan voters, who become more favorable toward and more likely to vote for opponent-party candidates and less likely to vote for co-partisans. Experimental and unique observational data capturing participants' second-by-second reactions to the debates show that policy information was the most important causal mechanism driving partisan moderation, especially among strong partisans. A follow-up survey shows that these effects persist in electorally competitive communities, whereas they dissipate in party strongholds. Policy-centered debates have the potential to reduce partisan polarization in new democracies, but the local political context conditions the persistence of these effects

Lateral Compartment Contact Pressures Do Not Increase After Lateral Extra-articular Tenodesis and Subsequent Subtotal Meniscectomy

© The Author(s) 2019. Background: Modified Lemaire lateral extra-articular tenodesis (LET) has been proposed as a method of addressing persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR). However, concerns remain regarding the potential for increasing lateral compartment contact pressures. Purpose: To investigate changes in tibiofemoral joint contact pressures after isolated ACLR and combined ACLR plus LET with varying states of a lateral meniscal injury. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knee specimens (mean age, 60.0 ± 3.4 years) were utilized for this study, with specimens potted and loaded on a materials testing machine. A pressure sensor was inserted into the lateral compartment of the tibiofemoral joint, and specimens were loaded at 0°, 30°, 60°, and 90° of flexion in the following states: (1) baseline (ACL- and anterolateral ligament–deficient), (2) ACLR, (3) ACLR with LET, (4) partial meniscectomy (removal of 50% of the posterior third of the lateral meniscus), (5) subtotal meniscectomy (removal of 100% of the posterior third of the lateral meniscus), and (6) LET release (LETR). Mean contact pressure, peak pressure, and center of pressure were analyzed using 1-way repeated-measures analysis of variance. Results: Across all flexion angles, there was no statistically significant increase in the mean contact pressure or peak pressure after ACLR plus LET with and without lateral meniscectomy compared with isolated ACLR. There was a significant reduction in the mean contact pressure, from baseline, after subtotal meniscectomy (69.72% ± 19.27% baseline; P =.04) and LETR (65.81% ± 13.40% baseline; P =.003) at 0° and after the addition of LET to ACLR at 30° (61.20% ± 23.08% baseline; P =.031). The center of pressure was observed to be more anterior after partial (0°, 30°) and subtotal (0°, 60°) meniscectomy and LETR (0°, 30°, 60°). Conclusion: Under the loading conditions of this study, LET did not significantly alter lateral compartment contact pressures when performed in conjunction with ACLR in the setting of an intact or posterior horn–deficient lateral meniscus. Clinical Relevance: This study should provide surgeons with the confidence that it is safe to perform LET in this manner in conjunction with ACLR without altering lateral compartment pressures, regardless of the status of the lateral meniscus

Emittance compensation with dynamically optimized photoelectron beam profiles

Much of the theory and experimentation concerning creation of a high-brightness electron beam from a photocathode, and then applying emittance compensation techniques, assumes that one must strive for a uniform density electron beam, having a cylindrical shape. On the other hand, this shape has large nonlinearities in the space-charge field profiles near the beam's longitudinal extrema. These nonlinearities are known to produce both transverse and longitudinal emittance growth. On the other hand, it has recently been shown by Luiten that by illuminating the cathode with an ultra-short laser pulse of appropriate transverse profile, a uniform density, ellipsoidally shaped bunch is dynamically formed, which then has linear space-charge fields in all dimensions inside of the bunch. We study here this process, and its marriage to the standard emittance compensation scenario that is implemented in most recent photoinjectors. It is seen that the two processes are compatible, with simulations indicating a very high brightness beam can be obtained. The robustness of this scheme to systematic errors is examined. Prospects for experimental tests of this scheme are discussed

A comparison of outcomes between bovine pericardial and porcine valves in 38 040 patients in England and Wales over 10 years

OBJECTIVES: Biological valves are the most commonly implanted prostheses for aortic valve replacement (AVR) surgery in the UK. The aim of this study was to compare performance of porcine and bovine pericardial valves implanted in AVR surgery with respect to survival and reintervention-free survival in a retrospective observational study. METHODS: Prospectively collected clinical data for all first-time elective and urgent AVRs with or without concomitant coronary artery bypass graft (CABG) surgery performed in England and Wales between April 2003 and March 2013 were extracted from the National Institute for Cardiovascular Outcomes Research database. Patient life status was tracked from the Office for National Statistics. Time-to-event analyses were performed using log-rank tests and Cox proportional hazards regression modelling with random effects/grouped frailty for responsible cardiac surgeons. RESULTS: A total of 38 040 patients were included (64.9 % bovine pericardial; 35.1 % porcine). Patient characteristics were similar between the groups. The median follow-up was 3.6 years. There was no statistically significant difference in survival (P = 0.767) (the 10-year surviva

Foreign acquisitions by UK limited companies: short- and long-run performance

Article; an earlier version was issued as Xfi working paper 04/01In this paper, we consider the short- and long-run performance of UK firms following foreign acquisitions. Based on a near-exhaustive sample of significant foreign acquisitions by UK companies over the period 1985–1994, we show that short-run returns are insignificantly different from zero irrespective of the location of the acquisition. Further analysis reveals that the distribution of the event period returns is determined by changes in the exchange rate, the presence of the acquiring firm in the target country and by US tax reforms. While long-run returns are not significantly different from zero on average, they show considerable variation by region. Specifically, firms under-perform following acquisition in the US, show insignificant returns following acquisitions in the EU and acquisitions elsewhere show significant positive returns. Examination of the distribution of these returns suggest that, in accordance with the ownership–location–internalisation hypothesis of foreign direct investment (FDI), long-run performance is more likely to depend on the firm-specific advantages such as R&D

Concepts and Measurement in Multimethod Research

This article argues that concept misformation and conceptual stretching undermine efforts to combine qualitative and quantitative methods in multimethod research (MMR). Two related problems result from the mismatch of qualitatively and quantitatively construed concepts. Mechanism muddling occurs when differences in the connotation of qualitatively and quantitatively construed concepts embed different causal properties into conceptual definitions. Conceptual slippage occurs when qualitatively and quantitatively construed concepts use incompatible nominal, ordinal, or radial scales. Instead of gaining leverage from the synthesis of large- and small-N analysis, these problems can push MMR in two diametrically opposed directions, emphasizing one methodological facet at the cost of the other.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline