The Effect of Control and Display Lag on UAS Internal Pilot Manual Landing Performance

An important characteristic of UASs is lag because it can become a considerable challenge to successful human-in-the-loop control. As such, UASs are designed and configured to minimize system lag, though this can increase acquisition and operation costs considerably. In an effort to cut costs, an organization may choose to accept greater risk and deploy a UAS with high system lag. Before this risk can be responsibly accepted, it must be quantified. While many studies have examined system lag, very few have been able to quantify the risk that various levels of lag pose to an internally piloted, manually landed UAS. This study attempted to do so by evaluating pilot landing performance in a simulator with 0 ms, 240 ms, and 1000 ms of additional lag. Various measures were used, including a novel coding technique. Results indicated that 1000 ms of lag was unsafe by all measures. They also indicate that 240 ms of lag degrades performance, but participants were able to successfully land the simulated aircraft. This study showed the utility of using several measures to evaluate the effect of lag on landing performance and it helped demonstrate that while 1000 ms poses a high risk, 240 ms of lag may be a much more manageable risk. Future research suggested by this research includes: investigating lag between 240 ms and 1000 ms, introducing different weather phenomena, developing system lag training techniques for operators, and investigating the effect of aides such as predictive displays and autopilot-assisted recovery

Drugs, Thugs, and Mariachis: An Institutional Response to Mexico’s Drug Cartels

Mexico represents a dichotomy of images: first, as a land of sun, surf, and a place of destiny for vacationers, and second, as providing a haven for violent drug cartels operating with virtual impunity from the power of the state that appears unable to provide a fundamental duty - public safety. In the current environment of cartel violence, festive similes of mariachis called narcocorridos are muffling traditional Mexican poems by singing ballads praising drug cartel leaders. Defying the government prohibition against radio stations playing this type of music, narcocorridos are often commissioned by drug cartels as a popular source of entertainment in cities proximate to the United States-Mexico border region

Pirates on the High Seas: An Institutional Response to Expanding U.S. Jurisdiction in Troubled Waters

Collective efforts among governments and regional organizations is a vital part of the fight against piracy that represents a security threat to all nation states with respect to freedom to navigate the high seas. This paper provides a concise overview of piracy, contemporary maritime drug laws, and cases among the circuit courts to illustrate the procedural concerns that affect fundamental constitutional principles of jurisdiction. A possible solution to existing substantive and procedural due process issues is establishment of a regional judicial institution with broad powers to preside over criminal prosecutions that include maritime crimes. The suggestion may be a viable means to resolve some concerns with respect to jurisdictional principles, regional stability, and the need for a comprehensive, coordinated response within the Western Hemisphere. Establishing a tribunal to.preside over enforcement practices alleviates dependency on the existing legal framework that may not fully resolve jurisdictional issues associated with maritime drug trafficking. In addition, a regional tribunal minimizes the need for the United States to function as the only viable, sovereign nation-state in the Americas to ensure that pirates engaged in illicit trades are not roaming the high seas with impunity

Auditor Judgment Confidence: Direct Evidence for the Process View

Although there has been considerable research on audit judgment processes and structures, one area that has received little attention is auditor judgment confidence. Determining the nature of confidence attainment has direct implications for audit practice, particularly regarding the timing of evidence evaluation leading to final judgments. The present study extends the early work of Pincus (1991) and is the first to provide direct evidence in support of the process view of audit judgment confidence

Effects of Nitrate Supplementation on In Vivo Muscle Torque Recovery From BaCl2-Induced Injury

During repair from muscle injury, muscle satellite cells depend on nitric oxide production by immune cells to proliferate and differentiate. Nitrate supplementation has been shown to improve muscle endurance and oxygen consumption, but little is known about the ability of nitrate supplementation to interfere with muscle regeneration following injury. PURPOSE: To investigate whether nitrate supplementation affects muscle recovery of force after muscle injury produced by intramuscular injection of barium chloride. METHODS: Transgenic male mice (12 weeks old) that express Td-Tomato fluorescent protein in Pax7+ cells (i.e., satellite cells; Pax7CreER-Ai9 mice) were treated with tamoxifen (2 mg in corn oil, i.p.) once a day for 5 days. Four days after the last tamoxifen injection, both legs were subjected to stimulation of the peroneal nerve to evoke contractions of the anterior crural muscles at different frequencies of stimulation (1-200 Hz; i.e., Torque-frequency curve), followed by intramuscular injections of 1.2% BaCl2 (w/v) to produce injury of the tibialis anterior (TA) and extensor digitorum longus (EDL) muscles of the right leg. The contralateral leg served as a non-injured control. Torque-frequency curves were tested for both legs on days 2, 7, 14 and 21 post injury. At day 21, mice were euthanized, and muscles were dissected for histology (TA) and ex-vivo muscle contractility (EDL). A group of mice was treated with 1 g/L of NaNO3 in drinking water (nitrate group) 1 week before muscle injury, and a second group of mice was not treated (water group). RESULTS: Mice treated with NaNO3 (nitrate group) showed smaller torque in the non-injured leg compared to water group (103 ± 3 vs 84 ± 2 Nmm/kg, for water vs nitrate groups, respectively). However, the torque produced by the injured leg normalized by the torque developed by the non-injured leg was not different between groups on days 2 (28 ± 13% vs 25 ± 1%), 7 (41 ± 4% vs 35 ± 2%), 14 (81 ± 7% vs 87 ± 1%) and 21 (104 ± 3% vs 105 ± 3%) for water and nitrate groups respectively. CONCLUSION: The data suggest that nitrate supplementation decreases nerve-stimulated torque development in uninjured leg but does not change the recovery of torque after BaCl2 injury. Support: TRDRP grant # T29KT0397CA (to L.N.

Single-Leg Resistance Exercise Training in Mice Leads to a Fast Increase in In Vivo Torque of Anterior Crural Muscles

Resistance exercise is known to produce muscle hypertrophy. However, little is known about the role of muscle satellite cells in generating new myofibers or in incorporating satellite cells to live myofibers during exercise training. PURPOSE: To investigate whether single-leg resistance exercise training can activate the incorporation of muscle satellite cells in mice. METHODS: Transgenic male mice (12 weeks old) that express Td-Tomato fluorescent protein in Pax7+ (i.e., satellite cells) cells (Pax7CreER-Ai9) were treated with tamoxifen (2 mg in corn oil, i.p.) once a day for 5 days. Three days later, mice were single-leg exercise trained (i.e stimulation of the peroneal nerve of the right leg of each mouse to evoke fused tetanic contractions [100 Hz] of the anterior crural muscles), 3x per week for either 1 or 2 weeks. Each training session was composed of 3-s contractions with 7 s recovery between contractions, 10 contractions each set, 5 sets with 5 min rest between sets. Before the first training session and 3 days after the last training session (1 week or 2 weeks training), torque produced by the ankle was measured at different frequencies of pulse-stimulation (1-200 Hz), mice were euthanized, and muscles were frozen for histological measurements. RESULTS: During each session of training, peak torque developed at the last contraction was ~30% of the torque developed in the initial contraction of the session suggesting fatigue development. Between sessions of training, initial torque was not significantly different suggesting that muscle recovered function between sessions. Torque measurements at different frequencies of stimulation 3 days after 1 week or 2 weeks of training showed a ~50% increase in maximal tetanic torque relative to the mice body weight, after 1 week of training but there were no additional changes at 2 weeks of training. Tibialis anterior muscle cross sectional area and number of Td-tomato positive myofibers were also measured in these mice. CONCLUSION: Resistance exercise training in mice by using single-leg electrical stimulations leads to a fast (i.e., 1 week) increase in muscle force development

Withering the citizen, managing the consumer: complaints in healthcare settings

This paper considers concepts of citizenship and consumerism in light of complaints about healthcare, which have risen since the early1990s, due to a greater willingness by the healthcare user to complain, and also the reforms in complaint systems. The narrow legal model for dealing with complaints has been replaced by a managerial model based on corporate sector practice that views complaint handling as a way of retaining customers and organisational learning. The managerial model has proved difficult to embed into the English NHS and has been superposed with a centralised regulatory system that aims to manage performance while also being responsible for reviewing, complaints and being responsive to complainants. It is argued that this may have positive consequences in terms of improving healthcare quality but more negatively, the promotion of consumerism within complaints processes has led to a loss of the right to due process and public accountability

Detecting violent and abnormal crowd activity using temporal analysis of grey level co-occurrence matrix (GLCM)-based texture measures

The severity of sustained injury resulting from assault-related violence can be minimized by reducing detection time. However, it has been shown that human operators perform poorly at detecting events found in video footage when presented with simultaneous feeds. We utilize computer vision techniques to develop an automated method of violence detection that can aid a human operator. We observed that violence in city centre environments often occur in crowded areas, resulting in individual actions being occluded by other crowd members. Measures of visual texture have shown to be effective at encoding crowd appearance. Therefore, we propose modelling crowd dynamics using changes in crowd texture. We refer to this approach as Violent Crowd Texture (VCT). Real-world surveillance footage of night time environments and the violent flows dataset were tested using a random forest classifier to evaluate the ability of the VCT method at discriminating between violent and non-violent behaviour. Our method achieves ROC values of 0.98 and 0.91 on our own real world CCTV dataset and the violent flows dataset respectively