Field boundaries in Great Britain: stock and change between 1984, 1990 and 1998.

Field boundaries are man-made features found worldwide and their multiple functions in agricultural landscapes are now widely recognised. These landscape features have declined drastically in many developed countries as a result of agricultural intensification. In Great Britain, field boundaries are regarded as elements of particular significance in the countryside, both in term of extent and value, whether ecological, cultural, or aesthetic. The Countryside Surveys of Great Britain, a national ecological, surveillance programme initiated in the late 1970s, provides information about the change in extent and ecological condition of field boundaries. In this paper, we present the main results on field boundaries derived from the latest survey, Countryside Survey 2000. These include stock and change of boundaries for the 1990-1998 period as well as an update of the previously published 1984-1990 data. Special attention is given to the evolution of the length of hedges. Applicability of the Countryside Survey methodology to other monitoring programmes and further use of the data is discussed together with the potential ecological consequences of the changes described in the paper.

Endothelial cell activity varies in patients at risk for the adult respiratory distress syndrome.

OBJECTIVE: The endothelial cell produces many bioactive compounds that are presumed to play important roles in the pathogenesis of the adult respiratory distress syndrome (ARDS). We postulated that individuals with sepsis and trauma-two at-risk diagnoses for the development of ARDS--might demonstrate differences in the degree of endothelial cell activity. DESIGN: Prospective cohort study. SETTING: Intensive care unit patients in a tertiary, university-affiliated, city hospital. PATIENTS: Fifty-five intensive care unit patients (19 with sepsis and 36 trauma patients). INTERVENTIONS: Plasma measurements of three endothelial cell products--von Willebrand factor antigen, soluble intercellular adhesion molecule-1 (ICAM-1), and soluble E-selectin-were performed within 8 hrs of patients meeting our inclusion criteria, and at the clinical onset of ARDS. MEASUREMENTS AND MAIN RESULTS: Twenty-six percent of the septic patients and 25% of the trauma patients developed ARDS. The median (and 25% to 75% quartiles) concentrations of all three mediators measured in the sepsis patients (von Willebrand factor antigen 399% [375% to 452%], ICAM-1 573 ng/mL [470 to 980], and soluble E-selectin 180 ng/mL [81 to 340]) were significantly higher (p < .001 for each individual analysis) than in the trauma patients (von Willebrand factor antigen 256% [217% to 310%], ICAM-1 148 ng/mL [113 to 210], and soluble E-selectin 42 ng/mL [31 to 65 ng/ mL]). In addition, neither the ICAM-1 nor soluble E-selectin concentrations measured in the trauma patients were different (p = .17 and p = .24, respectively) from normal controls. In those patients who developed ARDS, the differences in the concentrations of all three endothelial cell mediators between the sepsis and trauma patients persisted (p = .008 for von Willebrand factor antigen, p = .003 for ICAM-1, and p = .003 for E-selectin). CONCLUSION: These findings suggest that differences in endothelial cell activity exist between sepsis and trauma patients who are at risk for the development of ARDS.

The ITE Land classification: Providing an environmental stratification of Great Britain.

The surface of Great Britain (GB) varies continuously in land cover from one area to another. The objective of any environmentally based land classification is to produce classes that match the patterns that are present by helping to define clear boundaries. The more appropriate the analysis and data used, the better the classes will fit the natural patterns. The observation of inter-correlations between ecological factors is the basis for interpreting ecological patterns in the field, and the Institute of Terrestrial Ecology (ITE) Land Classification formalises such subjective ideas. The data inevitably comprise a large number of factors in order to describe the environment adequately. Single factors, such as altitude, would only be useful on a national basis if they were the only dominant causative agent of ecological variation.The ITE Land Classification has defined 32 environmental categories called 'land classes', initially based on a sample of 1-km squares in Great Britain but subsequently extended to all 240 000 1-km squares. The original classification was produced using multivariate analysis of 75 environmental variables. The extension to all squares in GB was performed using a combination of logistic discrimination and discriminant functions. The classes have provided a stratification for successive ecological surveys, the results of which have characterised the classes in terms of botanical, zoological and landscape features.The classification has also been applied to integrate diverse datasets including satellite imagery, soils and socio-economic information. A variety of models have used the structure of the classification, for example to show potential land use change under different economic conditions. The principal data sets relevant for planning purposes have been incorporated into a user-friendly computer package, called the 'Countryside Information System'.

Linking satellite and field survey data, through the use of gis, as implemented in Great Britain in the Countryside Survey 1990 project.

The Institute of Terrestrial Ecology (ITE) has been studying land use and the effects of land use on ecology for two decades. A series of national field surveys have been undertaken by the Land Use Section of ITE since 1978, the most recent being Countryside Survey 1990 (CS1990). The three-year project brought together field survey and remote sensing data which were analyzed using Geographical Information Systems (GIS). National and regional land-cover patterns were described and changes estimated.The data collected by the field survey part of CS1990 recorded stratified samples based on a land classification. Thematic maps for surveyed 1-km squares covered physiography, agriculture and semi-natural vegetation, forestry, structures and boundaries. The same sites were surveyed in 1984 and 1990 with 14 000 digital maps produced describing both years. GIS was used to generate stock figures for each year, and overlay allowed change between survey dates to be estimated.GIS was used to compare data collected from both field survey and satellite imagery so that both sets of information could be qualified when expressed as national figures.This paper describes the historical development of the ITE Land Classification, examines the way in which data were collected for surveys, with particular reference to Countryside Survey 1990, and shows how satellite and field survey data can be linked through GIS.

von Willebrand factor antigen levels are not predictive for the adult respiratory distress syndrome.

In patients with nonpulmonary sepsis, von Willebrand factor antigen (vWF:Ag or Factor VIIR:Ag) levels have been reported to be predictive for the development of the adult respiratory distress syndrome (ARDS). We addressed the ability to generalize these results by measuring serial Factor vWF:Ag levels in 96 patients at risk for the development of ARDS. Patients with sepsis, pancreatitis, hypertransfusion, witnessed aspiration of gastric contents, abdominal trauma, chest trauma, and multiple fractures were studied. Sequential measurements were obtained at enrollment into the study (T = 0), and T = 6, 12, 24, and 48 h. Subjects were grouped into sepsis and nonsepsis categories and analyzed according to the following outcome definitions: ARDS and non-ARDS. The mean values for the sepsis and nonsepsis groups were elevated above normal at all time points. A statistically significant difference occurred in the mean vWF:Ag level for the ARDS and non-ARDS patients in the nonsepsis group at T = 0 (p = 0.05). To assess the clinical utility of these results, ROC (receiver operating characteristics) curves were plotted at T = 0, and optimal cutoff values of vWF:Ag were determined. In the sepsis group, the best value for vWF:Ag above which patients would actually develop ARDS was 399%, resulting in a 70% sensitivity and a 47% specificity. For the non-sepsis patients, the optimal value was 273%, yielding a sensitivity of 64% and a specificity of 52%. We conclude that measuring vWF:Ag levels are not helpful in predicting the progression to ARDS in multiple at-risk patients.