Retrospective studies of operating problems in air transport

An epidemiological model for the study of human errors in aviation is presented. In this approach, retrospective data are used as the basis for formulation of hypotheses as to system factors which may have contributed to such errors. Prospective experimental studies of aviation operations are also required in order to prove or disprove the hypotheses, and to evaluate the effectiveness of intervention techniques designed to solve operational problems in the aviation system

Simulation studies of air transport operational problems

An experimental evaluation of the monitored approach procedure for conducting low visibility instrument approaches is described. Four airline crews each flew 16 approaches using the monitored procedure and 16 using a modified standard procedure in a DC-10 simulator under various conditions of visibility, wind shear and turbulence, and radar vectoring scenarios. In terms of system measures of aircrew performance, no major differences were found. Pilot opinion data indicate that there are some desirable characteristics of the monitored procedure, particularly with reference to the increased role of the flight engineer in conducting low visibility approaches. Rationale for developing approach procedures is discussed

Sedimentary flow heterogeneities in the Triassic U.K. Sherwood Sandstone Group: Insights for hydrocarbon exploration

Fluvial and aeolian sedimentary successions host important hydrocarbon resources as well as major groundwater aquifers. This review of the lithological characteristics of Triassic fluvio‐aeolian successions of the Sherwood Sandstone Group (United Kingdom) demonstrates how distance from a fluvial sediment source and rate of rift‐related tectonic subsidence play important roles in governing reservoir quality in continental successions. Increasing distance from the fluvial sediment source area results in increased porosity and permeability in deposits of mixed fluvial and aeolian reservoir successions that accumulated in arid and semiarid settings. Indeed, successions of the U.K. Sherwood Sandstone Group reveal an increase in the proportion of highly permeable deposits of aeolian origin with increasing distance from the principal uplands, represented by the Armorican Massif in northern France, which formed the main source for delivery of fluvial sediment to a series of rift basins. A progressive reduction in the discharge of fluvial systems entering and passing through a series of interlinked rift basins encouraged aeolian accumulation in more distal basins. Extensional tectonics enabled preservation of highly permeable aeolian facies in basins subject to high rates (≳100 m/Myr) of tectonic subsidence by rapidly placing such deposits below the water table. However, successions exclusively characterized by fluvial lithofacies record decreases in both porosity and permeability with increasing distance (~250–750 km) from the sediment source due to the coupling of porosity reduction and increasing clay content

Forest biodiversity, ecosystem functioning and the provision of ecosystem services

Forests are critical habitats for biodiversity and they are also essential for the provision of a wide range of ecosystem services that are important to human well-being. There is increasing evidence that biodiversity contributes to forest ecosystem functioning and the provision of ecosystem services. Here we provide a review of forest ecosystem services including biomass production, habitat provisioning services, pollination, seed dispersal, resistance to wind storms, fire regulation and mitigation, pest regulation of native and invading insects, carbon sequestration, and cultural ecosystem services, in relation to forest type, structure and diversity. We also consider relationships between forest biodiversity and multifunctionality, and trade-offs among ecosystem services. We compare the concepts of ecosystem processes, functions and services to clarify their definitions. Our review of published studies indicates a lack of empirical studies that establish quantitative and causal relationships between forest biodiversity and many important ecosystem services. The literature is highly skewed; studies on provisioning of nutrition and energy, and on cultural services, delivered by mixed-species forests are under-represented. Planted forests offer ample opportunity for optimising their composition and diversity because replanting after harvesting is a recurring process. Planting mixed-species forests should be given more consideration as they are likely to provide a wider range of ecosystem services within the forest and for adjacent land uses. This review also serves as the introduction to this special issue of Biodiversity and Conservation on various aspects of forest biodiversity and ecosystem services

Are Shock Index and Adjusted Shock Index useful in predicting mortality and length of stay in community-acquired pneumonia?

BACKGROUND: Community Acquired Pneumonia (CAP) is a common infection which is associated with a significant mortality. Shock index, heart rate divided by blood pressure, has been shown to predict mortality in several conditions including sepsis, acute myocardial infarction and traumatic injuries. Very little is known about the prognostic value of shock index in community acquired pneumonia (CAP). OBJECTIVE: To examine the usefulness of shock index (SI) and adjusted shock index (corrected to temperature) (ASI) in predicting mortality and hospital length of stay in patients admitted to hospital with CAP. METHODS: A prospective study was conducted in three hospitals in Norfolk & Suffolk, UK. We compared risk of mortality and longer length of stay for low (=1.0, i.e. heart rate > systolic BP) SI and ASI adjusting for age, sex and other parameters which have been shown to be associated with mortality in CAP. RESULTS: A total of 190 patients were included (males=53%). The age range was 18-101 years (median=76 years). Patients with SI & ASI >1.0 had higher likelihood of dying within 6 weeks from admission. The adjusted odds ratio for 30 days mortality were 2.48 (1.04-5.92; p=0.04) for SI and 3.16 (1.12-8.95; p=0.03) for ASI. There was no evidence to suggest that they predict longer length of stay. CONCLUSION: Both SI and ASI of >1.0 predict 6 weeks mortality but not longer length of stay in CAP