Do Complexity Measures of Frontal EEG Distinguish Loss of Consciousness in Geriatric Patients Under Anesthesia?

While geriatric patients have a high likelihood of requiring anesthesia, they carry an increased risk for adverse cognitive outcomes from its use. Previous work suggests this could be mitigated by better intraoperative monitoring using indexes defined by several processed electroencephalogram (EEG) measures. Unfortunately, inconsistencies between patients and anesthetic agents in current analysis techniques have limited the adoption of EEG as standard of care. In attempts to identify new analyses that discriminate clinically-relevant anesthesia timepoints, we tested 1/f frequency scaling as well as measures of complexity from nonlinear dynamics. Specifically, we tested whether analyses that characterize time-delayed embeddings, correlation dimension (CD), phase-space geometric analysis, and multiscale entropy (MSE) capture loss-of-consciousness changes in EEG activity. We performed these analyses on EEG activity collected from a traditionally hard-to-monitor patient population: geriatric patients on beta-adrenergic blockade who were anesthetized using a combination of fentanyl and propofol. We compared these analyses to traditional frequency-derived measures to test how well they discriminated EEG states before and after loss of response to verbal stimuli. We found spectral changes similar to those reported previously during loss of response. We also found significant changes in 1/f frequency scaling. Additionally, we found that our phase-space geometric characterization of time-delayed embeddings showed significant differences before and after loss of response, as did measures of MSE. Our results suggest that our new spectral and complexity measures are capable of capturing subtle differences in EEG activity with anesthesia administration-differences which future work may reveal to improve geriatric patient monitoring

A review and road map of entrepreneurial equity financing research

Equity financing in entrepreneurship primarily includes venture capital, corporate venture capital, angel investment, crowdfunding, and accelerators. We take stock of venture financing research to date with two main objectives: (a) to integrate, organize, and assess the large and disparate literature on venture financing; and (b) to identify key considerations relevant for the domain of venture financing moving forward. The net effect is that organizing and assessing existing research in venture financing will assist in launching meaningful, theory-driven research as existing funding models evolve and emerging funding models forge new frontiers

“Contagious Accountability”: A Global Multisite Randomized Controlled Trial on the Effect of Police Body-Worn Cameras on Citizens’ Complaints Against the Police

The use of body-worn cameras (BWCs) by the police is rising. One proposed effect of BWCs is reducing complaints against police, which assumes that BWCs reduce officer noncompliance with procedures, improve suspects’ demeanor, or both, leading to fewer complaints. We report results from a global, multisite randomized controlled trial on whether BWC use reduces citizens’ complaints. Seven discrete tests ( N = 1,847 officers), with police shifts as the unit of analysis ( N = 4,264), were randomly assigned into treatment and control conditions. Using a prospective meta-analytic approach, we found a 93% before–after reduction in complaint incidence ( Z = −3.234; p < .001), but no significant differences between trial arms in the studies ( d = .053, SE = .11; 95% confidence interval [CI] = [−.163, .269]), and little between-site variation ( Q = 4.905; p = .428). We discuss these results in terms of an “observer effect” that influences both officers’ and citizens’ behavior and assess what we interpret as treatment diffusion between experimental and control conditions within the framework of “contagious accountability.” This is the author accepted manuscript. The final version is available from SAGE Publications via http://dx.doi.org/10.1177/009385481666821

Wearing body cameras increases assaults against officers and does not reduce police use of force: Results from a global multi-site experiment

Police use of force is at the forefront of public awareness in many countries. Body-worn videos (BWVs) have been proposed as a new way of reducing police use of force, as well as assaults against officers. To date, only a handful of peer-reviewed randomised trials have looked at the effectiveness of BWVs, primarily focusing on use of force and complaints. We sought to replicate these studies, adding assaults against police officers as an additional outcome. Using a prospective meta-analysis of multi-site, multi-national randomised controlled trials from 10 discrete tests with a total population of +2 million, and 2.2 million police officer-hours, we assess the effect of BWVs on the rates of (i) police use of force and (ii) assaults against officers. Averaged over 10 trials, BWVs had no effect on police use of force ( d = 0.021; SE = 0.056; 95% CI: –0.089–0.130), but led to an increased rate of assaults against officers wearing cameras (d = 0.176; SE = 0.058; 95% CI: 0.061–0.290). As there is evidence that cameras may increase the risk of assaults against officers, more attention should be paid to how these devices are implemented. Likewise, since other public-facing organisations are considering equipping their staff with BWVs (e.g. firefighters, private security, traffic wardens), the findings on risks associated with BWVs are transferrable to those occupations as well. This is the final version of the article. It first appeared from Sage via https://doi.org/10.1177/1477370816643734

Report: increases in police use of force in the presence of body-worn cameras are driven by officer discretion: a protocol-based subgroup analysis of ten randomized experiments

© 2016, The Author(s). Objectives: Our multisite randomized controlled trial reported that police body-worn cameras (BWCs) had, on average, no effect on recorded incidents of police use of force. In some sites, rates of use of force decreased and in others increased. We wanted to understand these counter-intuitive findings and report pre-specified subgroup analyses related to officers’ discretion on activating the BWCs. Methods: Using pre-established criteria for experimental protocol breakdown in terms of treatment integrity, ten experimental sites were subgrouped into “high-compliance” (no officer discretion applied to when and where BWCs should be used; n = 3), “no-compliance” (treatment integrity failure in both treatment and control conditions; n = 4), and tests where officers applied discretion during treatment group but followed protocol in control conditions only (n = 4). Results: When officers complied with the experimental protocol and did not use discretion, use of force rates were 37 % lower [SMD = (−.346); SE = .137; 95 % CI (−.614) – (−.077)]; when officers did not comply with treatment protocol (i.e., officers chose when to turn cameras on/off), use of force rates were 71 % higher [SMD = .392; SE = .130; 95 % CI (.136) – (.647)], compared to control conditions. When full discretion (i.e., overall breakdown of protocol) was applied to both treatment and control conditions, null effects were registered [SMD = .009; SE=.070; 95 % CI (−.127) – (.146)], compared to control conditions. Conclusions: BWCs can reduce police use of force when then officers’ discretion to turn cameras on or off is minimized—in terms of both case types as well as individual incidents. BWCs ought to be switched on and the recording announced to suspects at early stages of police–public interactions. Future BWCs tests should pay close attention to adherence to experimental protocols

Pharmacokinetic profile of a 24-hour controlled-release OROS(® )formulation of hydromorphone in the presence and absence of food

BACKGROUND: The objective of this study was to compare the pharmacokinetic profile of a novel, once-daily, controlled-release formulation of hydromorphone (OROS(® )hydromorphone) under fasting conditions with that immediately after a high-fat breakfast in healthy volunteers. The effect of the opioid antagonist naltrexone on fasting hydromorphone pharmacokinetics also was evaluated. METHODS: In an open-label, three-way, crossover study, 30 healthy volunteers were randomized to receive a single dose of 16 mg OROS(® )hydromorphone under fasting conditions, 16 mg OROS(® )hydromorphone under fed conditions, or 16 mg OROS(® )hydromorphone under fasting conditions with a naltrexone 50-mg block. Plasma samples taken pre-dose and at regular intervals up to 48 hours post-dose were assayed for hydromorphone concentrations. Analysis of variance was performed on log-transformed data; for mean ratios of 0.8 to 1.2 (20%), differences were considered minimal. Bioequivalence was reached if 90% confidence intervals (CI) of treatment mean ratios were between 80% and 125%. RESULTS: The mean geometric ratios of the fed and fasting treatment groups for maximum plasma concentration (C(max)) and area under the concentration-time curve (AUC(0-t); AUC(0-∞)) were within 20%. Confidence intervals were within 80% to 125% for AUC(0-t )and AUC(0-∞ )but were slightly higher for C(max )(105.9% and 133.3%, respectively). With naltrexone block, the hydromorphone C(max )increased by 39% and the terminal half-life decreased by 4.5 hours. There was no significant change in T(max), AUC(0-t )or AUC(0-∞). CONCLUSION: Standard bioavailability measures show minimal effect of food on the bioavailability of hydromorphone from OROS(® )hydromorphone. Naltrexone co-administration results in a slight increase in the rate of absorption but not the extent of absorption. TRIAL REGISTRATION: Clinical Trials.gov NCT0039929

Mitigation of Moral Hazard and Adverse Selection in Venture Capital Financing: The Influence of the Country’s Institutional Setting

A venture capitalist (VC) needs to trade off benefits and costs when attempting to mitigate agency problems in their investor-investee relationship. We argue that signals of ventures complement the VC’s capacity to screen and conduct a due diligence during the pre-investment phase, but its attractiveness may diminish in institutional settings supporting greater transparency. Similarly, whereas a VC may opt for contractual covenants to curb potential opportunism by ventures in the post-investment phase, this may only be effective in settings supportive of shareholder rights enforcement. Using an international sample of VC contracts, our study finds broad support for these conjectures. It delineates theoretical and practical implications for how investors can best deploy their capital in different institutional settings whilst nurturing their relationships with entrepreneurs

Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling

This paper investigates the dependence of synchronization transitions of bursting oscillations on the information transmission delay over scale-free neuronal networks with attractive and repulsive coupling. It is shown that for both types of coupling, the delay always plays a subtle role in either promoting or impairing synchronization. In particular, depending on the inherent oscillation period of individual neurons, regions of irregular and regular propagating excitatory fronts appear intermittently as the delay increases. These delay-induced synchronization transitions are manifested as well-expressed minima in the measure for spatiotemporal synchrony. For attractive coupling, the minima appear at every integer multiple of the average oscillation period, while for the repulsive coupling, they appear at every odd multiple of the half of the average oscillation period. The obtained results are robust to the variations of the dynamics of individual neurons, the system size, and the neuronal firing type. Hence, they can be used to characterize attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related work available at http://arxiv.org/abs/0907.4961 and http://www.matjazperc.com/

The evolution and adoption of equity crowdfunding: entrepreneur and investor entry into a new market

Equity crowdfunding (ECF) offers entrepreneurs an online social media marketplace where they can access numerous potential investors who, in exchange for an ownership stake, may supply them with finance. In this paper, we describe the evolution of this market in the UK. Using an inductive qualitative longitudinal research design, we analyse the emerging views of entrepreneurs and investors towards ECF. Our interviewees include large and small-scale investors, as well as market participants who have chosen not to invest or raise funds via ECF. We find that the large financial flows to entrepreneurs in the UK via the ECF platforms, nearly half a billion GBP since 2011, have probably been largely incremental to traditional sources of early stage entrepreneurial finance. Moreover, our research indicates that for the most part, investors appear to understand and appropriately evaluate the risks that they are bearing; ECF investments are perceived as a high risk, high return component within individuals’ portfolios. Investors also use their communication with peers and entrepreneurs via the ECF platform as a learning tool. On the entrepreneurs’ side, ECF allows them to test their products, to develop their brand, to build a loyal customer base and to turn customers into investors. We conclude that policymakers, with the support of a locally appropriate regulatory framework, could support equity crowdfunding as one of the market choices available for entrepreneurs looking to start or grow their ventures