Departure Approval Request Compliance Effects on Overhead Stream Insertion

Integrated Arrival-Departure-Surface (IADS) air traffic management relies on information sharing and integration between automation systems for efficiency, predictability, and throughput improvements throughout the National Airspace System (NAS). The NASA Airspace Technology Demonstration 2 (ATD-2) project supports this effort by integrating SWIM (System Wide Information Management) information and evaluating and refining potential TFDM (Terminal Flight Data Manager) functionality in a surface traffic management system fielded at Charlotte-Douglas International Airport (CLT). Among the IADS areas under study during ATD-2 is the use of electronically negotiated departure times for efficiently inserting flights into overhead traffic streams. Stream-insertion accuracy is important for reducing excessive vectoring that negatively impacts the NAS by increasing controller workload along with aircraft fuel burn and emissions. Departure-time approval requests (APREQs) provide center-approved departure times to allow for smooth stream insertion. In this presentation, TBFM (Time-Based Flow Management) and ATD-2 flight summary data are used to empirically show that APREQ compliance leads to improved stream insertion

A novel oral syringe for dosing and administration of multiparticulate formulations : acceptability study in preschool and school children

The popularity of multiparticulate formulations (MPs) as a paediatric dosage form continues to increase. MPs comprise of multiple small units that are easy-to-swallow. Currently, MPs are commonly manufactured into unit doses that are either swallowed whole or opened prior to administration. While this is an acceptable approach, dosing is envisioned to be optimised with a “standard” paediatric device which can better harness the flexible dosing potential of MPs. We evaluated a novel oral syringe (Sympfiny™, HS Design, Morristown, NJ, USA) that is being developed as a tool to dispense and administer MPs to children. Forty children, 4–12 years old, received 0.5, 1.2, and 2.0 mL doses of placebo MPs using the oral syringe with spring water or a drink of choice to complete sample intake. Acceptability was recorded as those able to completely swallow the dose and participants also rated dose acceptability on a 5-point scale. The ability to completely swallow the dose decreased as dose volume increased; the smallest dose was completely swallowed by 87.5% (35/40) children, and 69.4% (27/39) of children confirmed their willingness to take the sample as a daily medicine. Larger doses, 1.2 and 2.0 mL, gave values of 55% and 57.5% for the doses completely swallowed and 58.8% and 51.72% for willingness to take the sample as a daily medicine, respectively. Use of a drink of choice showed no increase in swallowability as compared with water. The novel oral syringe being developed is an appropriate device for dispensing doses flexibly and administering neutral tasting MPs directly to the mouth in the lower dose range without the need for a co-administration vehicle in children aged 4–12 years

Electronic Departure Approval Requests in ATD-2 Daily Operations

The NASA Air Traffic Management Demonstration 2 project is investigating Integrated Arrival-Departure-Surface (IADS) air traffic management through progressive refinement of a surface air traffic management system fielded at Charlotte-Douglas International Airport. Among the IADS areas under study are departure release-time approval request (APREQ) traffic management initiatives. This paper presents a review of APREQ operations and compliance data from daily electronic APREQ negotiations. It describes APREQ-compliance improvements observed as the ATD-2 electronic negotiation process has matured and discusses contributing factors

ATD-2 Briefing to Southwest Data Science Community

The purpose of this presentation is to provide Southwest Airlines, an ATD-2 (Airspace Technology Demonstration-2) airline industry partner, with a project overview and the breadth of ATD-2 data analysis activities

Rehabilitation versus surgical reconstruction for non-acute anterior cruciate ligament injury (ACL SNNAP): a pragmatic randomised controlled trial

BackgroundAnterior cruciate ligament (ACL) rupture is a common debilitating injury that can cause instability of the knee. We aimed to investigate the best management strategy between reconstructive surgery and non-surgical treatment for patients with a non-acute ACL injury and persistent symptoms of instability.MethodsWe did a pragmatic, multicentre, superiority, randomised controlled trial in 29 secondary care National Health Service orthopaedic units in the UK. Patients with symptomatic knee problems (instability) consistent with an ACL injury were eligible. We excluded patients with meniscal pathology with characteristics that indicate immediate surgery. Patients were randomly assigned (1:1) by computer to either surgery (reconstruction) or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment), stratified by site and baseline Knee Injury and Osteoarthritis Outcome Score—4 domain version (KOOS4). This management design represented normal practice. The primary outcome was KOOS4 at 18 months after randomisation. The principal analyses were intention-to-treat based, with KOOS4 results analysed using linear regression. This trial is registered with ISRCTN, ISRCTN10110685, and ClinicalTrials.gov, NCT02980367.FindingsBetween Feb 1, 2017, and April 12, 2020, we recruited 316 patients. 156 (49%) participants were randomly assigned to the surgical reconstruction group and 160 (51%) to the rehabilitation group. Mean KOOS4 at 18 months was 73·0 (SD 18·3) in the surgical group and 64·6 (21·6) in the rehabilitation group. The adjusted mean difference was 7·9 (95% CI 2·5–13·2; p=0·0053) in favour of surgical management. 65 (41%) of 160 patients allocated to rehabilitation underwent subsequent surgery according to protocol within 18 months. 43 (28%) of 156 patients allocated to surgery did not receive their allocated treatment. We found no differences between groups in the proportion of intervention-related complications.InterpretationSurgical reconstruction as a management strategy for patients with non-acute ACL injury with persistent symptoms of instability was clinically superior and more cost-effective in comparison with rehabilitation management

Benefits of Surface Departure Metering While 'Doing No Harm' to Other Operational Metrics

Learn how the ATD-2 analytical team has used various sources and metrics to verify that the operational system follows a do no harm mandate while also providing efficiency and predictability benefits

Optimization of Ramp Area Aircraft Push Back Time Windows in the Presence of Uncertainty

It is well known that airport surface traffic congestion at major airports is responsible for increased taxi-out times, fuel burn and excess emissions and there is potential to mitigate these negative consequences through optimizing airport surface traffic operations. Due to a highly congested voice communication channel between pilots and air traffic controllers and a data communication channel that is used only for limited functions, one of the most viable near-term strategies for improvement of the surface traffic is issuing a push back advisory to each departing aircraft.This dissertation focuses on the optimization of a push back time window for each departing aircraft. The optimization takes into account both spatial and temporal uncertainties of ramp area aircraft trajectories. The uncertainties are described by a stochastic kinematic model of aircraft trajectories, which is used to infer distributions of combinations of push back times that lead to conflict among trajectories from different gates. The model is validated and the distributions are included in the push back time window optimization. Under the assumption of a fixed taxiway spot schedule, the computed push back time windows can be integrated with a higher level taxiway scheduler to optimize the flow of traffic from the gate to the departure runway queue. To enable real-time decision making the computational time of the push back time window optimization is critical and is analyzed throughout

Temporal and spatial expression of mRNAs encoding pathogenesis-related proteins during ethylene-promoted leaflet abscission in Sambucus nigra

Differential screening of a cDNA library generated from RNA extracted from ethylene-treated leaflet abscission zones of Sambucus nigra resulted in the isolation of 20 abscission-related clones. These clones could be grouped into seven families. Sequencing of members of these families revealed that the majority encoded pathogenesis-related (PR) proteins, and these could be identified by sequence homology as a polyphenol oxidase (PPO), a PR-1 type protein, a Chial type chitinase, a PR-4 type protein similar to the potato win peptides, a PR-6 type proteinase inhibitor, a Chia4 type chitinase and a metallothionein-like protein (Coupe, Taylor & Roberts 1995, Planta 197, 442–447). Northern analysis revealed that these mRNAs were not expressed in freshly excised material but accumulated primarily in the abscission zone tissue after 18 h of exposure to ethylene at a time when abscission of the leaflet explants had reached 70%. Expression of the PPO and the Chia4-type chitinase was ethylene-dependent while that of the PR-4 type was up-regulated in the abscission zone tissue in the absence of the gas. The characterization of these mRNAs and their encoded proteins is presented and their possible roles during abscission are discussed