Haul Air Research Articles

Perioperative air travel increases the risk of venous thromboembolism following lower limb arthroplasty.

PurposeVenous thromboembolism (VTE) is a significant complication following lower limb arthroplasty (LLA). There is a paucity of evidence with regard to air travel following LLA. Orthopaedic surgeons are often asked by patients regarding air travel following LLA, and there is a need for evidence to guide these patients.MethodsThis was a retrospective cohort study. We identified two cohorts, one travelling to and from the hospital by air and another, by land. All patients received routine preoperative and post-operative care, and thromboprophylaxis, as per our hospital guidelines. We collected baseline demographics, ASA score and incidence of VTE at 90 days using local patient records and a national joint registry. We also recorded data on flight time and overland distance of travel.ResultsTwo hundred and forty-three patients travelled by air; mean flight time was 74 min. In total, 5498 patients travelled a mean 25.3 miles over land to the hospital. No differences in baseline demographics or ASA score were observed. Four patients developed a VTE in the flight group, with 32 patients suffering a VTE in the control group. There was a significant difference in the VTE rate between the flight and control groups (p < 0.05); the relative risk of developing a VTE in the flight group was 2.85.ConclusionsIn our cohort, perioperative short haul air travel is associated with an increased risk of VTE at 90 days following LLA. Orthopaedic surgeons must ensure that their patients are cognizant of the risks associated with perioperative air travel and take measures to minimise these risks.

Strategy for 19-seat hybrid-electric short haul air transportation

This paper addresses a way to implement greener aviation technologies, such as hybrid-electric propulsion, into the air transportation network to respond to the increasing environmental challenges posed by growing air traffic. New routes could be established between small airports to ensure better air connectivity in Europe while also connecting disadvantaged areas and relieve congestion at hub airports. Such routes could, for example, be served by micro feeder or 19-seat hybrid-electric aircraft, which produce low or no emissions, have lower operating costs, and are more applicable to environmental constraints. To achieve this and overcome the various challenges posed by the new hybrid-electric technologies, a new strategic roadmap for short-haul air transport is needed to optimize network services with small hybrid-electric aircraft.

THE 3 A’S OF STOPOVER DESTINATION ATTRACTIVENESS: ACCESS, AMBIENCE, AND ATTRACTIONS

There has been relatively little research investigating the phenomenon of stopovers during long haul air travel. The aim of this exploratory study was to identify determinants of stopover destination attractiveness. Quantitative data was collected from consumers in two countries in the northern hemisphere and two in the southern hemisphere. The survey instrument was informed by previously published qualitative research involving personal interviews in the four countries, to identify salient attributes of stopover destinations. Data from the 2000 participants in the current study identified three dimensions of destination attractiveness in the context of a stopover during long haul international air travel, which positively influence attitudinal loyalty. The findings contribute to an emerging field of research into stopover destinations. Also, the results provide tourism marketers with practical insights into the influence of previous visitation on travellers’ perceptions of stopover destinations, and the potential determinants of destination attractiveness in the context of stopovers during long haul air travel.

Perceptions of Stopover Destinations During Long Haul Air Travel: A Mixed Methods Research Approach in Four Countries

Research into the phenomenon of stopovers during long haul air travel emerged only recently in the tourism literature. In this article a contribution to this new field is made by reporting perceptions of Dubai, in the context of an international stopover destination, during long haul air travel between UK/Europe and Australasia/South Pacific, relative to three competing places (Singapore, Hong Kong, Abu Dhabi). A mixed methods research approach was used. The first stage involved personal interviews with 66 consumers in the UK, France, Australia, and New Zealand to identify salient attributes of stopover destinations, and a pilot survey involving 777 consumers in Australia and France. A refined online survey was then used with a combined sample of 2,000 consumers in the same four markets, to identify determinant attributes of stopover destination attractiveness, as well as Dubai's perceived strengths and weaknesses. The study identified determinant attributes of stop-over destination attractiveness that have not featured in destination image research. The results support the propositions that 1) destination image might vary across travel contexts, and 2) there is a positive effect of previous visitation on destination image and attitudinal loyalty. Methodologically the study demonstrates the efficacy of combining the repertory test with importance–performance analysis, in destination image research.

Smart system for FOD detection

The fair description of the properties and reactions of asphalt layers under on-site conditions is necessary in order to maintain correct air terminal life standards as well as to coordinate the asphalt workouts of board exercises and to modify and accept the robotic reaction model. Continuous progressions in the Micro-Electro - Mechanical Sensor (MEMS)/Nano-Electro-Mechanical Sensor (NEMS) progresses and remote sensor systems coupled with capable vitality finding ideal models provide long haul chances, consistent, continuous reaction evaluation and well-being observation of the simple transport frameworks. This paper presents a synopsis survey of some ongoing investigations that have concentrated on the improvement of cutting edge brilliant detecting and checking frameworks for interstate asphalt framework with potential applications for long haul air terminal asphalt wellbeing observing. A few instances These future implementations include: the utilization of remote Radio-Frequency Identification (RFID) labels for deciding warm inclinations in asphalt layers; self-fueled MEMS/NEMS multifunction sensor framework prepared to do constant, remote checking of restricted strain, temperature and dampness content in air terminal asphalt that will, in the end, forestall calamitous disappointments, for example, blow-ups on runways during heat waves.

Myeloproliferative Neoplasms: An in-Depth Case-Control (MOSAICC) Study

IntroductionThe Classic Myeloproliferative Neoplasms (MPNs), characterised by an over production of one or more cells of the myeloid lineage, are classified into polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF). Despite the identification of numerous genetic mutations, a paucity of information relating to medical and lifestyle factors contributing to the aetiology of these diseases remains.MethodsThe MOSAICC Study was an exploratory case-control study of MPNs. MPN patients were recruited between two sites, Belfast and Southampton, in preparation for a planned UK-wide investigation. Population controls (identified by General Practitioners) and non-blood relative/friend controls were also recruited. Participants completed a telephone-based questionnaire seeking information on a range of medical, environmental, lifestyle and occupational risk factors. Risk factors were assessed using unconditional logistic regression with adjustment for potential confounders.ResultsRisk factors identified included smoking [≥25 pack years vs. never: odds ratio (OR) 3.14, 95% confidence interval (CI) 1.26-7.87], increasing childhood household density [>2 vs <1 Child(ren)/room: OR 3.29, 95% CI 1.31-8.30], history of heart disease (OR 3.31, 95% CI 1.23-8.87), CT scans (≥3 vs. none: OR 4.92, 95% CI 1.55-15.67), having an implant (OR 10.77, 95% CI 1.01-3.10), and pig ownership (OR 5.92, 95% CI 1.17-29.92). Alcohol was associated with a reduced risk of MPNs (OR 0.49, 95% CI 0.28-0.88) as was home working on car exhausts (OR 0.33, 95% CI 0.12-0.88), painting at home (OR 0.49, 95% CI 0.28-0.86) and short haul air travel (p for trend 0.012). Participants working in occupations with high exposure to environmental tobacco smoke had an excess risk of MPN (OR 2.45, 95% CI 1.12-5.37). Work-based radiation and solvent exposure also appeared to increase risk of MPNs (p<0.05).ConclusionsThis exploratory study has confirmed a reported association between cigarette smoking and MPNs. It has identified some potential novel risk factors including work-based radiation and solvent exposure. The findings of this study need to be replicated in a larger, adequately powered, study in order to identify important risk factors for the classic MPNs.Conflict of InterestThe authors declare no conflict of interest.Acknowledgments: The MOSAICC Study team acknowledges the support of the National Institute for Health Research, through the Northern Ireland Cancer Research Network (NICRN) and for Southampton the Central South Coast Cancer Network (CSCCN). The team thank those who have participated in the MOSAICC study and the personnel who assisted in the recruitment of patients. DisclosuresMesa:CTI Biopharma: Research Funding; Promedior: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Incyte Corporation: Research Funding; Pfizer: Research Funding; NS Pharma: Research Funding; Genentech: Research Funding; Gilead: Research Funding.

Leisure Travel: Implications for Airline Alliances

The rationale behind the formation of airline alliances includes the reaping of scale and scope economies and the acquisition of marketing and branding advantages. To really add value to the airline customer, however, alliances should consider the purpose of travel, i.e. they should appreciate and understand the derived nature of the airline product. The relevant literature seems to understate this issue or at best focus on business passengers. Given the rising importance of leisure travel and tourism in the world economy, its implications should be explicitly assessed. The emergence of low cost carriers and the subsequent simplifications in the holiday packages offered by charter airlines have played a major role in boosting leisure travel in Europe at least. Still, the intelligent management of frequent flyer programmes and the creation of a seamless network in long haul (or even intercontinental) air travel may induce leisure passengers to opt for an allied airline instead. This paper addresses the topic by undertaking primary research in the form of semi-structured interviews with airline executives and structured questionnaires addressed to passengers. The interviewees are supportive of the view that alliances of network carriers may offer benefits to leisure passengers although they do recognise the competitive threat posed by low cost carriers. Similarly, the statistical analysis of the questionnaire results reveals that frequent flyers and more affluent respondents are more knowledgeable about strategic alliances and have a tendency to prefer allied carriers for long-haul but not for short-haul flights. This outcome may add to the understanding of airline alliances and consumer behaviour and have important implications for airline strategy at a global level.

Competition and cooperation between high-speed rail and air transportation services in Europe

New high-speed rail (HSR) lines may have an enormous influence on the provision of air services. The attention has been devoted to competition between both transportation modes but in some cases HSR services may also have an intermodal complementary role with air transportation. By taking a supply oriented empirical analysis, we study the impact of HSR on air service frequencies and seats offered by airlines in large European countries. We emphasize the distinction between routes with and without a hub airport as an endpoint and we also examine the influence of the location of the HSR station. We generally find direct competition between HSR and airlines, but we also provide some evidence that HSR can provide feeding services to long haul air services in hub airports, particularly in hub airports with HRS stations.

Quantifying the carbon footprint of religious tourism: the case of Hajj

Travel and tourism is one of the largest industries in the world and is a large contributor of greenhouse gas (GHG) emissions. Religious tourism is a fast growing sector within the tourism industry. Pilgrimage to Mecca, Hajj, is one of the oldest and largest religious tourism events in the world drawing 2.79 million participants from all around the world in 2011. Managing an event at such scale poses many challenges on multiple fronts, not the least are the environmental management of its impacts. Quantifying the environmental impacts of the event is a key element in setting up proper and effective environmental management programs. This article uses life cycle methodology to assess the Global Warming Potential (GWP) from the main activities of the Hajj event. On average each pilgrim contributes 60.5 kg CO2-eq per day as a result of transportation, hotel stay, meals and waste management. Long haul air travel is the largest contributor of greenhouse gases, followed by lodging then food with each accounting to 60%, 18% and 13%, respectively. Infrastructure provision, upstream emissions and aviation higher altitude emission effects account to more than 50% of the total GWP of the event. The potential of applying the concept of carbon neutrality by extending preservation principles built-in the traditional Hajj rituals is also discussed.

Adaptive Body Support System for Aircraft Seat

The development of new technology enables the comfort service becoming an important requirement in the air travel industry. Long haul air travel may cause different physiological and psychological discomfort of aircraft passenger. Most of the aircraft company treats the passenger comfort as a main priority for the user’s acceptance of their airline. In order to improve the aircraft passenger body comfort during long haul air travel, an adaptive body support system was developed and embedded in the economy class aircraft seat. In this paper, we describe the development of adaptive body support system.

The effects of air travel on performance measures of elite Australian rugby league players

The current study explored the effects of short haul air travel within the same country on elite Australian rugby league (RL) players (n=12) during two away and two home games of elite competition. Physiological tests of handgrip strength and leg power were assessed along with psychological tests and perceptions of leg soreness and tiredness on the day before the game (Time 1 and Time 2) and on game day (Time 3). Game statistics of tackles and metres gained were assessed for the games analysed. Significant differences were found for daily analyses of life demands for athletes (DALDA) worse than normal responses at Time 2 (2.50±3.23 vs. 3.50±3.93; P=0.04), Karolinska Sleepiness Scale (KSS) at Time 2 (2.88±1.51 vs. 3.71±1.37; P=0.011) and leg tiredness at Time 3 (3.38±1.66 vs. 2.35±1.70; P=0.004) between home and away games. The analysis of game statistics identified that more metres were gained during home games (83.6±49.1 vs. 63.0±30.1; P=0.02) and more tackles made while playing away (18.4±9.2 vs. 14.3±6.7; P=0.016). The results suggest that short haul air travel without crossing time zones results in symptoms of travel fatigue but does not appear to negatively impact on elite RL players ability to perform strength and power tasks. Different game tactics (attacking vs. defensive) occurred between home and away games however, it is unclear whether travel fatigue or a home advantage (HA) is associated with this finding.

Leslie Le Quesne

Outcomes focused surgeon who worked on deep vein thromboses Leslie Le Quesne, who has died aged 91, was a bold and innovative surgeon, renowned research scientist, and revered teacher. As...

Haematological Changes at Altitude

Hypobaric hypoxia is associated with an increase in erythropoesis and an increased thrombotic risk. This is true of long haul air travel, mountaineering expeditions and longer stays at altitude. Studies...

The Effect of Refueling Stop on Long Haul Air Transport Greenhouse Emissions

A study on the environmental impact and fuel consumption of a long haul aircraft has been performed. Target of the study is to investigate the beneficial effect of refueling in long range flights, in terms of fuel consumption and CO2 emissions, while taking into account the adverse effect on flight duration. This has been achieved using the ‘Hermes’ aircraft performance model, developed at Cranfield University. In a further step, a parametric study has been performed in order to take into account non ideal conditions, where the refueling station is positioned further than mid-distance and extra range is required to be flown. Such data can be useful for scheduling real-life missions featuring refueling stops. The results show that the viability limit is affected by both type of the aircraft and payload, while a minimum range exists, under which the beneficial effect of refueling diminishes.

Explanations for coagulation activation after air travel.

It is unknown whether venous thrombosis after long haul air travel is exclusively attributable to immobilization. We determined whether the following mechanisms were involved: hypoxia, stress, inflammation or viral infection. In a case crossover setting in 71 healthy volunteers who were exposed to an 8-h flight, 8-h movie marathon and 8 h of regular activities, we compared markers for several hypothetical pathways: plasminogen activator inhibitor-1 (PAI-1), stress, plasma factor (F)VIII coagulant activity (FVIIIc), soluble P-selectine (sP-selectine), interleukin-8 (IL-8) and neutrophil elastase. We reported earlier an activated clotting system, as evidenced by thrombin generation, in 17% of volunteers after the flight. PAI-1 increased by 4.2 ng mL(-1) (CI95:-49.5 to 6.5) in volunteers with an activated clotting system whereas it decreased in those without (-20.0 ng mL(-1), CI95:-33.2 to -14.0). FVIIIc levels rose more in individuals with clotting activation (18.0%, CI95:-1.0 to 33.0) than in those without (2.0%, CI95:-2.0 to 5.0). The increases in FVIIIc were not associated with stress, which appeared unrelated to clotting activation. sP-selectin increased in those with clotting activation (3.5 microg L(-1), CI95: -3.0 to 10.0), but decreased in those without (-0.5 microg L(-1), CI95: -2.0 to 2.0). Changes in levels of neutrophil elastase or IL-8 were not different between the subjects with and without clotting activation. Our results do not support the hypotheses that stress, infection or air pollution are involved in the development of a prothrombotic state in air travellers. After long haul air travel, this state is more pronounced in patients with risk factors and may be caused by hypoxia, triggering systemic inflammation and platelet activation, leading to coagulation induction and degranulation of platelets.

High hematocrit as a risk factor for venous thrombosis. Cause or innocent bystander?

In the lay press it is frequently stated that long haul air travel causes venous thrombosis through dehydration in the airplane, leading to hyperviscosity of the blood, which in its turn favors thrombosis. The common advice that is given to prevent thrombosis after air travel is, therefore, ‘to

Comparing the CO2 emissions and contrail formation from short and long haul air traffic routes from London Heathrow

Abstract This paper considers the relative climate impacts of long haul and short haul air travel. This is particularly important in the context of changing markets for air travel. New competing aircraft technologies will enhance competition between the hub and spoke model of aircraft operations and that of smaller aircraft operating direct routes for long haul trips. The substitution of shorter trips by high-speed rail could also free otherwise constrained airport capacity for additional long haul flights. Previous comparisons have focused on fuel consumption per passenger km so long haul trips, where a much higher proportion of the journey is in the relatively efficient cruise phase, are more efficient than shorter trips. This study considers the additional role of contrails, believed to be important for the net climate impact of aviation. Short aircraft trips tend not to reach the very high altitudes attained by long haul cruising aircraft and so encounter different atmospheric conditions and have different probabilities of contrail formation. By including consideration of the variability in contrail formation conditions throughout the year, estimates of the linear contrail produced along various aircraft trajectories are obtained. The potential to mitigate contrail impacts by altering the flight schedule is also discussed.

The value and usage of ticket flexibility for short haul business travellers

Fully flexible business class and “full economy” airline tickets are aimed at meeting the needs of business travellers whose travel requirements may change after a ticket is purchased. The provision of these products has implications for airlines’ revenue management systems, which may lead to overbooking and denied boarding. Low-cost carriers have developed a method by which tickets can be changed only when required. This paper investigates the usage and value of ticket flexibility by business travellers as the popularity of high fare-fully flexible tickets has fallen in recent years. A survey of 284 business travellers showed that business travellers change their flight arrangements in only 32% of short haul trips. A stated preference study investigated the likelihood of respondents to change tickets in three hypothetical scenarios. The results indicate that to extend a business trip for business purposes travellers are confident that their company will bear the cost of changing a ticket valuing additional time at about £54 per hour but that the value of personal time when travelling is fairly low at £15 per hour. The study concludes that business travellers do not need to change their tickets often and that when they do, low-cost carriers offer a more cost-efficient method of providing ticket flexibility. This pay-for-usage approach to ticket flexibility undermines the traditional airlines’ pricing structures and this has contributed to the reduced, relative value of business class and full economy class tickets for short haul air travel.

Deep vein thrombosis and air travel: record linkage study

Objective To investigate the time relations between long haul air travel and venous thromboembolism.Design Record linkage study using the case crossover approach.Setting Western Australia.Participants 5408 patients admitted to hospital with...

Case report: bilateral calf (tibial) deep venous thrombosis following air travel

Objectives: To describe an interesting case of bilateral calf (tibial) deep venous thrombosis (DVT) in a traveller. Methods: Clinical case notes and reports of further investigations were analysed in the light of the existing literature concerning DVT and travellers. Results: A 56-year-old university lecturer presented within 48 h of a return to New Zealand from international travel abroad. An otherwise fit and healthy man he developed bilateral calf pains most notable on arising the day of presentation, although he reported some mild pain in the lower legs within 5 h of landing at Auckland. He reported no other complaints. Physical examination was unremarkable, except for the bilateral calf tenderness and being overweight. An urgent outpatient ultrasound to both lower limbs was reported as follows: ‘There is evidence of extensive thrombus involving the paired posterior tibial veins of both calves’. He was admitted to hospital for 24 h and started on low-molecular weight heparin. On completion of the course of heparin, he was further treated orally with warfarin. A follow-up assessment with a Clinical Haematologist occurred one month after hospitalisation. Conclusions: The present case illustrates bilateral calf (tibial) DVT in an otherwise fit male traveller following extensive long haul travel. It also illustrates the need to consider the possible diagnosis and the need for bilateral ultrasound scanning of the legs, particularly in travellers undertaking long haul air travel, who are symptomatic. All travellers undertaking extensive, long-haul air travel need to be warned of the risks of DVT and venous thromboembolism (VTE) and advised of appropriate preventive measures as have been outlined. In addition, all travellers should be aware of the signs and symptoms of DVT/VTE and of the need to seek medical advice should they develop them; in order to help prevent progression of a DVT to a VTE.