bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in seedling growth behaviour among species: trait correlations across species, and trait shifts along nutrient compared to rainfall gradients
Authors: Wright Ian J. , Westoby Mark
Published: March 2003

1 Species‐pairs from woody dicot lineages were chosen as phylogenetically independent contrasts (PICs) to represent evolutionary divergences along gradients of rainfall and nutrient stress, and within particular habitat types, in New South Wales, Australia. Seedlings were grown under controlled, favourable conditions and measurements were made for various growth, morphological and allocation traits.

2 Trait correlations across all species were identified, particularly with respect to seedling relative growth rate (RGR) and specific leaf area (SLA), a fundamental measure of allocation strategy that reflects the light‐capture area deployed per unit of photosynthate invested in leaves.

3 Across all species, SLA, specific root length (SRL) and seed reserve mass were the strongest predictors of seedling RGR. That is, a syndrome of leaf and root surface maximization and low seed mass was typical of high RGR plants. This may be a high‐risk strategy for individual seedlings, but one presumably mitigated by a larger number of seedlings being produced, increasing the chance that at least one will find itself in a favourable situation.

4 Syndromes of repeated attribute divergence were identified in the two sets of gradient PICs. Species from lower resource habitats generally had lower SLA. Thus, in this important respect the two gradients appeared to be variants of a more general ‘stress’ gradient.

5 However, trends in biomass allocation, tissue density, root morphology and seed reserve mass differed between gradients. While SLA and RGR tended to shift together along gradients and in within‐habitat PICs, no single attribute emerged as the common, primary factor driving RGR divergences within contrasts. Within‐habitat attribute shifts were of similar magnitude to those along gradients.
The influence of nectar and pollen availability on pollen transfer by individual flowers of oil‐seed rape (Brassica napus) when pollinated by bumblebees (Bombus lapidarius)
Authors: Cresswell James E.
Published: March 2003

1 Levels of nectar and pollen were manipulated in individual flowers of oil‐seed rape, Brassica napus, which were then offered to foraging bumblebees (Bombus lapidarius) for a single visit.

2 The durations of flower visits by bumblebees increased with the amount of nectar, but were unaffected by the level of available pollen. The bees’ flower‐handling routine may have become behaviourally fixed by the expectation of low pollen rewards, which prevailed in the experimental garden.

3 The effects of nectar provision on both pollen import (deposition on stigma) and export (removal from anthers) were studied. The amount of pollen transferred during a bumblebee’s visit was affected only by the amount of pollen that the flower presented.

4 Manipulated flowers that presented a large amount of available pollen received approximately three times more pollen on their stigmas during a bee’s visit than flowers with little available pollen, which suggests that autogamous pollen transfer contributes substantially to pollen deposition when pollen availability is high. The gradual dehiscence of the anthers in this species means that available pollen accumulates only if pollinator visits are infrequent, when the increased autogamy may act to ensure adequate pollination.

5 There was no relation between the quantity of nectar residue that a bee left after visiting a manipulated flower and the mean duration of its visits to unmanipulated flowers. Therefore, variation among individuals in the duration of visits to unmanipulated flowers apparently resulted from differences in foraging speed rather than from variation in the thoroughness of nectar removal.
The genesis of two Picea–Cladina forests in northern Sweden
Authors: Hörnberg G. , Östlund L. , Zackrisson O. , Bergman* I.
Published: March 2003

1
 In northern Fennoscandia a rare forest type, characterized by Cladina species and Picea abies, occurs on dry productive sites outside the range of permafrost but close to the Scandes mountains.

2
 We determined the history of vegetation development and disturbance of two Picea–Cladina forests to test the hypothesis that this forest type has a natural origin.

3  We used a combination of several retrospective vegetation history and archaeological methods, i.e. the analysis of pollen, macroscopic charcoal, dendroecological data, written historical sources, maps and ancient remains.

4
 The results suggest that the Picea–Cladina forests investigated are not the products of purely natural factors.

5
 Under the influence of harsh climatic conditions and anthropogenic impact, mainly by repeated fires, grazing, trampling and probably also selective cutting of Pinus, mixed coniferous forests, dominated by feather mosses and dwarf shrubs, may have evolved into the Picea–Cladina type.

6
 Repeated anthropogenic use of fire, already established c. 2000 years ago, may have been used to create lichen‐dominated areas, initially to attract game but later to improve winter grazing resources for reindeer. This finding contradicts the general view that Saami nomads did not use fire to alter forest vegetation.
Geomorphic processes and spatial patterns of primary forest succession on the Bogue Chitto River, USA
Authors: Robertson Kevin M. , Augspurger Carol K.
Published: March 2003

1 The Bogue Chitto River, Louisiana, USA, is a meandering river with 16 early successional tree species having > 1% relative dominance. We hypothesized that geomorphic processes associated with river planform promote predictable spatial patterns of tree species within each river bend by influencing the physical conditions under which the forest is initially established. We predicted that (i) species of trees differ in their location of recruitment along the point bar, and trees on older land reflect the spatial patterns of recent recruits; (ii) the location of recruitment differs among tree species in elevation, soil texture, herbaceous cover and light; and (iii) a specific pattern of elevation, soil texture and tree species in the earliest stage of forest succession characterizes multiple river bends in a reach.

2 On the floodplain interior to one bend, we mapped all trees and sampled seedlings and saplings, elevation, soil texture, herbaceous cover and light. In newly established forest adjacent to the point bars of eight bends, we surveyed spatial patterns of tree species, elevation and soil texture.

3 Trees of most species had characteristically become established along either the upstream or downstream segment of each point bar. Variation in tree species composition was gradual both along the point bar and along an axis of increasing age of land. The locations of recruitment and mature trees were the same for eight of 11 common species on the focal river bend.

4 The locations of tree recruitment and of mature trees of specific species on the focal bend were related to spatial patterns of elevation (corresponding to flood regime), soil texture, light, herbaceous cover and the inferred pattern of shear stress by flood water on the point bar. The same patterns of elevation and soil texture and locations of tree species characterized multiple river bends.

5 Geomorphic processes related to the river planform of the Bogue Chitto River promote spatially complex but predictable patterns of primary forest succession.
The role of resource interactions and seedling regeneration in maintaining a positive feedback in hemlock stands
Authors: Catovsky S. , Bazzaz F. A.
Published: March 2003

1 When a species influences conditions at a site to promote recruitment of conspecifics, the community may remain dominated by that species until the next major disturbance. We examined the occurrence of possible mechanisms for such a positive feedback in one community where it may be important: forests dominated by eastern hemlock (Tsuga canadensis).

2 Intact soil divots were collected from a hemlock stand in central Massachusetts, USA, and placed in shade‐houses at either 1.5% or 60% full sun. Soil was amended with nitrogen (5 g m−2 year−1), lime (1 kg m−2 year−1; to increase soil pH) or left untreated. Emergence, survival and growth of seedlings arising from the soil seed bank were subsequently monitored.

3 Light availability had a very large influence on seedling regeneration dynamics. Birch (Betula spp.) seedlings were most sensitive of all species to light availability, with low light reducing emergence by 43% and substantially decreasing seedling growth (by 99%) and survival (by 94%). In contrast, light treatments had smaller effects on performance of other species [hemlock and white pine (Pinus strobus)]. Birch survival was also increased by nitrogen addition, but only in low light. Liming had only marginal effects on seedling performance.

4 Differential seedling responses to resource availability led to dominance of final seedling communities by hemlock in low light, unamended soils (i.e., under conditions naturally found in hemlock stands), but by birch in high light, as well as in low light, nitrogen‐amended soils.

5 Positive feedbacks in hemlock stands are mediated both by availability of light and nitrogen, and by species’ life‐history strategies.
Competition between roots and soil micro‐organisms for nutrients from nitrogen‐rich patches of varying complexity
Authors: Hodge A. , Stewart J. , Robinson D. , Griffiths B. S. , Fitter A. H.
Published: March 2003

1 We usedLolium perenneplants grown in microcosms to investigate the responses of root demography, plant N capture, soil fauna populations and microbial community profiles to five organic patches containing the same amount of N but differing in their chemical and physical complexity and C : N ratio. All patches were dual labelled with15N/13C. Control patches contained the background sand : soil mix only.

2 There was rapid decomposition in, and plant N capture from, the patches of lowest C : N ratio. Early in the experiment13C was detected in the soil atmosphere and15N in the shoots. No13C enrichment was detected in the plant material.

3 The rate of root production was slowest in the most complex patch (L. perenneshoot material) but accelerated when patches were simpler and had lower C : N ratios. There was no difference in root mortality between treatments.

4 Nitrogen concentrations of shoots and roots and shoot biomass were greater in the N‐containing patches than controls, except for the most complex patch, while root biomass did not differ with treatments.

5 Total plant N capture was 45–54% of that initially added in patches that had a C : N ratio < 4. However, in the most complex patch (C : N ratioc. 21 : 1) plants captured only 11% of the N added.

6 Biomass of microbial‐feeding protozoa was related to soil NO3–‐N concentration in the patch but not to numbers of microbial‐feeding nematodes. Patches of greater complexity increased the metabolic diversity of the microbial community (i.e. the number of substrates used in a Biolog GN plate) and altered the pattern of substrate utilization.

7 At harvest, the amount of patch‐derived N estimated to be in the microbial biomass was much smaller (i.e. 7–13%) than in the plant tissues. Thus, plants were highly effective competitors with micro‐organisms when capturing N supplied in patches with a low C : N ratio.
Effects of resource competition and herbivory on plant performance along a natural productivity gradient
Authors: Van Der Wal René , Egas Martijn , Van Der Veen Adriaan , Bakker Jan
Published: March 2003

1 The effects of resource competition and herbivory on a target species, Triglochin maritima, were studied along a productivity gradient of vegetation biomass in a temperate salt marsh.

2 Transplants were used to measure the impact of grazing, competition and soil fertility over two growing seasons. Three parts of the marsh were selected to represent different successional stages; Triglochin reached local dominance at intermediate biomass of salt‐marsh vegetation. At each stage, three competition treatments (full plant competition, root competition only, and no competition) and three grazing treatments (full grazing, no grazing on Triglochin, and no grazing on Triglochin or neighbours) were applied to both seedlings and mature plants.

3 Competition and herbivory reduced biomass and flowering of Triglochin. The impact of grazing was strongest at the stage with the lowest biomass, while both herbivory and competition had a significant impact at the stage with the highest biomass. When plants were protected from direct herbivory, competition operated at all three successional stages.

4 Grazing reduced light competition when vegetation biomass was low or intermediate, but at high biomass there was competition for light even when grazing occurred. Herbivore exclusion increased the effects of plant competition. Except at low biomass, the negative impact of plant competition on Triglochin performance was greater than the positive effect of not being grazed.

5 Grazing played a minor role in seedling survival and establishment which were largely controlled by competitive and facilitative effects.

6 Once established, the persistence of Triglochin will be determined largely by grazing. Intense grazing in the younger marsh and increasing competition for light in the older marsh will restrict the distribution to sites with intermediate biomass.
Ecological gradients, subdivisions and terminology of north‐west European mires
Authors: Wheeler B. D. , Proctor M. C. F.
Published: March 2003

1 The historical development of mire ecology and terminology is reviewed in relation to evolving concepts and perceptions, and the diverse schools and traditions of vegetation and habitat description and research.

2 Most ecological and floristic variation within north‐west European mire vegetation is accounted for by three ecological gradients: the acid base‐poor vs. neutral, base‐ and bicarbonate‐rich gradient; the gradient in fertility related to availability of the limiting nutrient elements N and P; and the water level gradient. Effects of salinity and the spring–flush–fen gradients are of more local significance, usually easily recognized. Land use is an important additional factor.

3 The mineral‐soil‐water limit between ombrotrophic and minerotrophically influenced sites is not sharp, and cannot be related to consistent differences in either vegetation or water chemistry. It should be abandoned as a general main division within mires.

4 The most important natural division is between ‘bog’, with pH generally < 5.0, low Ca2+, and Cl– and SO42– as the main inorganic anions, typically dominated by sphagna, ericoids and calcifuge Cyperaceae, and ‘fen’, with pH generally > 6.0, high Ca2+ and HCO3–, vegetation rich in dicotyledonous herbs and ‘brown mosses’. This division is reflected in a bimodal distribution of pH.

5 The terms oligotrophic, mesotrophic and eutrophic should refer only to nutrient richness (fertility, mainly N and P), not to base richness (metallic cations and pH).

6 It is recommended that ‘mire’ should embrace both wetlands on peat and related communities on mineral soils, that ‘bog’ (unqualified) should encompass both ombrotrophic and weakly minerotrophic mires, including ‘bog woodland’, and that ‘fen’ should be restricted to base‐rich mires but include both herbaceous and wooded vegetation (‘fen carr’).

7 Definitions are given for a range of broadly defined categories that should cover most vegetation types commonly encountered. The relation of these to British national vegetation classification types and to major units in European phytosociology is outlined.
Responses of the biennial forest herb Alliaria petiolata to variation in population density, nutrient addition and light availability
Authors: Meekins J. Forrest , McCarthy Brian C.
Published: March 2003

1
Alliaria petiolata, a European biennial herb, is an important pest in temperate North American deciduous forests. Habitat resource structure has probably been important for invasion and proliferation of this species.

2
Alliaria was grown in an experimental garden at two densities (equivalent to 17 and 170 plants m−2), three nutrient levels (no, low, or high nutrient addition) and three light levels (ambient sunlight and two shading treatments) to determine the effects of environmental heterogeneity on growth, reproduction and resource allocation in both mature and rosette plants.

3 Overall, rosette growth and allocation patterns were significantly affected by all three variables tested. Low plant density, nutrient addition and high light availability resulted in plants with more leaves and greater dry weight biomass. Biomass allocation to shoots was greatest for plants in high‐density and low‐light treatments. Leaf chlorophyll content was significantly greater for plants in the two shaded treatments.

4 Mature plants also responded to environmental manipulation with significantly greater total dry weight biomass at low plant density, high light availability and with nutrient addition. Low density and high light availability resulted in significantly higher seed production. Plants in the lowest light treatment allocated significantly more biomass to shoot production and less to root production. Leaf chlorophyll content was lowest for plants in the highest light treatment and increased with nutrient addition at the two highest light treatments.

5 Plants growing at high density responded to nutrient addition and light attenuation in the same direction but with greatly reduced magnitude compared with plants growing at low density. The effect of irradiance was the most important determinant of all facets of growth and allocation patterns in both rosettes and mature plants.

6 Our results indicate that although density and site fertility may play important roles in Alliaria invasion and establishment, light availability may be the most important factor affecting subsequent growth and proliferation.
Influence of environmental factors on the growth and interactions between salt marsh plants: effects of salinity, sediment and waterlogging
Authors: Huckle Jonathan M. , Potter Jacqueline A. , Marrs Rob H.
Published: March 2003

1 Artificial environmental gradients were established in a series of pot experiments to investigate the effect of salinity, sediment type and waterlogging on the growth, and interactions between Spartina anglica and Puccinellia maritima. In each experiment, one environmental variable was manipulated and plants grown in pairwise combinations to examine the effect of the environmental factor on the intensity of intra‐ and interspecific interactions, quantified using the Relative Neighbour Effect (RNE) index.

2 Puccinellia was found to exert an asymmetric, one‐way competitive dominance above ground over Spartina in experiments where gradients of sediment type and waterlogging were established. The intensity of the competition was highest in conditions with the least abiotic stress and lower or non‐existent where stress was increased.

3 The intensity of the above‐ground competition was greatest in loam and least in sand sediments. Reduction in competitive intensity in sand was accompanied by an increase in below‐ground Spartina biomass and it is suggested that the production of rhizomes is a potential mechanism by which this species can expand vegetatively into areas without competition.

4 Interspecific competition on Spartina from Puccinellia also varied in intensity in the waterlogging experiment, being more intense in non‐immersed treatments, where abiotic stress was reduced.

5 The competitive dominance of Puccinellia and the competition avoidance mechanism shown by Spartina in these experiments help to explain the successional interactions between the species along environmental gradients in natural salt marsh communities.
A modelling analysis of the genetic variation of phenology between tree populations
Authors: Chuine I. , Belmonte J. , Mignot A.
Published: March 2003

1 The phenology of temperate woody plants is commonly assumed to be locally adapted to climate.

2 However, the high gene flow expected in forest tree species, the high between year variance of thermal conditions at a given place and the high plasticity of phenology regarding temperature, lead us to hypothesize that genetic variation of phenology between populations is likely to be insignificant for many lowland tree species.

3 Using phenological models, we investigated variation in the timing of flowering between locations for four European clonal trees and between different populations of a further five species.

4 Models were also used to study the responses of the different populations to climate change by simulating transfers of each population to different locations.

5 While clinal variations can be observed in the phenological response to temperature between populations, only one species (Corylus avellana) showed significantly different responses between populations and even then only one of three populations could be separated from the others.

6 Hypothetical transfers show that the differences observed between populations depend on the thermal conditions at the location of transfer, and that these differences are less marked in warmer conditions.

7 Our results indicate that local adaptation will probably not be a serious constraint in predicting the phenological responses of temperate lowland tree species to global warming.
Nitrogen retention by Hylocomium splendens in a subarctic birch woodland
Authors: Eckstein R. L.
Published: March 2003

1 Nutrient dynamics and growth of the feathermoss Hylocomium splendens were studied in a subarctic birch woodland. My aims were to estimate the species’ nutrient use strategy (and its determinants: mean residence time (MRT) and annual nutrient productivity (aNP)) and to unravel possible traits related to nutrient conservation and their implications for ecosystem nitrogen flux. Three methods to estimate nutrient losses in bryophytes were evaluated: a conventional growth analysis technique, a retrospective analysis and a 15N‐tracer approach.

2 Estimates for nitrogen retention varied between 3 and 10 years as a result of the different N pools considered by the three methods. Growth analysis results depended on the distinction between live and dead tissues, whereas retrospective analysis gave valuable information on N release from decaying segments but did not measure MRT within the living segments. Valid estimates of MRT were obtained by a 15N‐tracer approach.

3 MRT and aNP of H. splendens were similar to values typically found in woody evergreen vascular plants. Efficient nutrient recycling and a relatively long segment life span were responsible for the long residence time of nitrogen. Feathermosses show efficient nutrient acquisition, nutrient recycling and acropetal transport; nutrient losses will therefore be small.

4 Dominant bryophytes may retard the nutrient turnover at the forest floor through their production of acidic nutrient‐poor organic matter and their negative effect on soil temperature, and they may therefore function as autogenic ecosystem engineers.
Shifts in trait‐combinations along rainfall and phosphorus gradients
Authors: Fonseca Carlos Roberto , Overton Jacob McC. , Collins Bronwyn , Westoby Mark
Published: March 2003

1 If different factors inhibiting plant growth, e.g. low rainfall or low soil nutrients, were to select for species that have similar constellations of traits, then the unfavourable factors might usefully be grouped together as ‘stress’.

2 We offer a method for assessing this issue. A species mixture at a site is described by a point on a plane with two traits as axes. Change along an environmental gradient is then represented as a trajectory across the trait‐plane. Trajectories along different environmental gradients are compared.

3 We measured leaf width, specific leaf area (SLA) and mature canopy height for the 386 perennial species found at 46 sites spread along rainfall and soil total phosphorus gradients in south‐eastern Australia. Each trait was lognormally distributed across species within sites, hence the mean of log10(trait) satisfactorily described the species mixture at each site.

4 Combinations of assemblage‐mean leaf width with SLA followed similar trajectories as rainfall and soil total P decreased. For these traits in this setting, the method indicated that low rainfall and low soil P favour similar trait‐combinations.

5 Mature plant height also decreased along both rainfall and soil P gradients, and thus was positively correlated with leaf width and SLA at the level of assemblage means. The rainfall trajectories involving height behaved differently from the soil P trajectories, especially at rainfalls belowc. 400 mm year−1, where assemblage‐mean height declined much further than at low soil P.

6 Across all species, traits were only very loosely correlated (r2from 0.04 to 0.17). For leaf width and SLA, evolutionary divergences were positively correlated, both before and after cross‐correlation with divergence in rainfall and soil P was removed. This latter measures evolutionary divergence correlation within habitat. For height the picture was more complicated. Considering these within‐habitat divergence correlations, species that were taller at maturity tended to have lower SLA and leaf width. This pattern is the reverse of the broad geographical correlation of assemblage means, showing that the patterns across assemblages result from species being selectively sifted from the regional flora into sites, not from evolutionary or cross‐species correlations.

7 The trait‐combination trajectory approach showed some commonalities between low soil nutrient and low rainfall habitats with regard to traits favoured in species occurring there, but also some differences. The approach has potential for clarifying which environmental factors can usefully be grouped together as ‘stress’, and which trait combinations can usefully be regarded as part of a syndrome favoured by stress.
Phylogeny and the niche structure of meadow plant communities
Authors: Silvertown Jonathan , Dodd Mike , Gowing David
Published: March 2003

Because related species tend to be ecologically similar, it has long been recognized that the phylogenetic relationships between species in a community are likely to influence its structure. Previous investigations of the influence of phylogeny on community structure have generally shown that congeneric species are more frequent than would be expected if communities were randomly assembled. Because, under most theories of coexistence, stable coexistence requires ecological differences between species, the apparent excess of coexisting congeners suggests that trait differences important to coexistence must be recently evolved, arising near the tips of phylogenetic trees.

We test this hypothesis in two meadow plant communities for which we have good evidence of niche segregation along axes defined by hydrological conditions.

Niche overlaps were calculated and compared against null models for (i) all species in the community, (ii) species within genera, (iii) genera within families, (iv) families within the eudicots and monocots, and (v) eudicots and monocots.

Against expectation, we found that community structure was the cumulative result of niche separation arising at a range of phylogenetic levels and therefore that niche differences have been accumulated through the evolutionary history of species.
BRIEF COMMUNICATION: Evaluating changes in life expectancy and survival in the elderly
Authors: Walker Alexander R.P. , Charlton Karen E.
Published: March 2003

Introduction: In view of current international interest and research on the elderly, numerous questions present themselves. Examples are: how rapidly are populations ageing? Is physical and functional decline in old age inevitable? Can morbidity be compressed into the final years of life? Are social, medical and other resources available for coping with the increasing numbers of elderly? Not least, how do old people themselves feel about ageing?
RESEARCH LETTER: What are quality of life improvements measuring and do they last? An explanatory model
Authors: Long Michael J.
Published: March 2003

To the Editor: The growing propensity to use the many validated instruments that measure improvements in physical, psychological and social wellbeing following clinical intervention raises two important questions. Are clinical interventions more likely to impact physical functions than psychological and social functions? Since it has been argued (Brook 1973, Donabedian 1980; Bergner 1989; Kaplan et al. 1989) that quality of life instruments should quantify benefits from clinical intervention that are additional to traditionally measured clinical benefits, are quality of life benefits additive to traditional clinical benefits? An important corollary is that if quality of life assessment does not add to the information derived from typical clinical evaluation, is it worth the additional cost? An explanatory model of the relationship between clinical outcome measures and quality of life outcome measures that result from clinical (medical) intervention is presented.
The role of qualitative research in broadening the ‘evidence base’ for clinical practice
Authors: Ma Rosaline S. Barbour
Published: March 2003

This paper presents the case for seeking to broaden the ‘evidence base’ of medicine and health care by the inclusion of qualitative research findings. In order for qualitative research to make a significant contribution, advocates of this approach must demonstrate its ability to address questions of relevance to practice and proponents of EBM must rethink their ideas as to what may constitute a research question. A definition of qualitative research is provided, highlighting the somewhat different assumptions which underpin this model. The potential contribution of qualitative findings is assessed and the paper examines the ways in which such insights can be utilized. Finally it addresses the question as to how qualitative findings can be incorporated in the ‘evidence base’.
A comparison of a Bayesian vs. a frequentist method for profiling hospital performance
Authors: Austin Peter C. , Naylor C. David , Tu Jack V.
Published: March 2003

The objective of this study was to compare the classification of hospitals as outcomes outliers using a commonly implemented frequentist statistical approach vs. an implementation of Bayesian hierarchical statistical models, using 30‐day hospital‐level mortality rates for a cohort of acute myocardial infarction patients as a test case. For the frequentist approach, a logistic regression model was constructed to predict mortality. For each hospital, a risk‐adjusted mortality rate was computed. Those hospitals whose 95% confidence interval, around the risk‐adjusted mortality rate, excludes the mean mortality rate were classified as outliers. With the Bayesian hierarchical models, three factors could vary: the profile of the typical patient (low, medium or high risk), the extent to which the mortality rate for the typical patient departed from average, and the probability that the mortality rate was indeed different by the specified amount. The agreement between the two methods was compared for different patient profiles, threshold differences from the average and probabilities. Only marginal agreement was shown between the Bayesian and frequentist approaches. In only five of the 27 comparisons was the kappa statistic at least 0.40. The remaining 22 comparisons demonstrated only marginal agreement between the two methods. Within the Bayesian framework, hospital classification clearly depended on patient profile, threshold and probability of exceeding the threshold. These inconsistencies raise questions about the validity of current methods for classifying hospital performance, and suggest a need for urgent research into which methods are most meaningful to clinicians, managers and the general public.
Reliability and validity of the Intercollegiate Stroke Audit Package
Authors: Gompertz P. H. , Irwin P. , Morris R. , Cstat D. Lowe MSc , Rutledge Z. , Rudd A. G. , Pearson M. G.
Published: March 2003

The aim of this study was to assure the validity and reliability of the Intercollegiate Stroke Audit Package as used in the National Sentinel Audit of Stroke. The Intercollegiate Working Party for Stroke, which included most stakeholders, including patients, devised the audit standards. These were submitted to a formal consensus (modified Delphi) survey before the audit questions were developed and piloted for validity and reliability. Following the pilot, Help Booklets were developed to promote the involvement of all disciplines as auditors in the national sentinel audit of stroke and ensure inter‐rater reliability. During the national audit each Trust was asked to double rate the first five cases with auditors of different disciplines working independently. A total of 886 case notes were double‐rated in 184 separate sites (median 5, range 1–5 per site). Trusts used auditors from different disciplines in 77% of cases. After excluding the ‘No answer’ cases the kappa score for items ranged from 0.49 to 0.87 (median 0.70, IQR 0.63–0.78). Very good agreement was found for seven of the 45 items, good agreement for 30 items, and moderate agreement for eight items. This large study, across a range of hospital sites and involving many disciplines, demonstrates that careful piloting of audit tools, with use of clear instructions to auditors, promotes the reliability of data.
How to validate clinically important change in health‐related functional status. Is the magnitude of the effect size consistently related to magnitude of change as indicated by a global question rating?
Authors: Middel Berrie , Stewart Roy , Bouma Jelte , Sonderen Eric van , Heuvel Wim J. A. van den
Published: March 2003

Some clinical trials perform repeated measurement over time and estimate clinically relevant change in an instrument’s score with global ratings of perceived change or so‐called transition questions. The conceptual and methodological difficulties in estimating the magnitude of clinically relevant change over time in health‐related functional status (HRFS) are discussed. This paper investigates the concordance between the amount of serially assessed change with effect size estimates (the researcher’s perspective) and global ratings of perceived change (the patient’s perspective). A total of 217 patients who were scheduled for diagnostic examination were included, and the Minnesota Living with Heart Failure Questionnaire, extended with MOS‐20 items, was assessed before and after medical intervention (percutaneous transluminal coronary angioplasty, coronary artery bypass grafting or pharmaco‐therapy). Global questions were applied to assess perceived change over time for every item from domains of physical and emotional functioning and used as the external criterion of relevant change in the analysis of items. Global questions corresponding with overall change in these domains were used in the comparison of change in physical and emotional functioning scales. Two effect size indices were used: (i) ES (mean change/SDpooled) and (ii) ES (mean change/SDchange). A method is described to calculate a value indicating the extent of discordance between the researcher’s interpretation of magnitude of change and the external criterion (the patient’s perspective). Findings suggest that effect size (ES) (mean change/SDpooled) was in keeping with the magnitude of change indicated by patients’ judgements, or their category of subjective meaning, for all scales. Furthermore, in cases in which the magnitude of change estimated with the SRM (mean change/SDchange) was not confirmed empirically by the external criterion ratings, the discordance could be interpreted as a trivial discordance.
Explaining the use and non‐use of community‐based long‐term care services by caregivers of persons with dementia
Authors: Markle‐Reid Maureen , Browne Gina
Published: March 2003

The purpose of this paper is to synthesize and critically evaluate the current literature that explains the use and non‐use of formal community‐based long‐term care services by caregivers of persons with dementia. There are four issues related to formal community service use by caregivers: reluctance to initiate formal services; under‐utilization of available services; delayed utilization of services; and inappropriate utilization of services. Despite substantial research efforts to understand these issues, the reasons for low rates of community service use by this population remains unclear. Common methodological problems and limitations in the underlying theoretical assumptions in the literature, as they relate to caregivers of persons with dementia, have limited the usefulness of the current research for informing practice and policy. A conflict‐theory model of decision‐making is proposed as an alternative theoretical framework for understanding the particularity and complexity of the decision‐making process leading up to the initiation of formal service use. Utilization of formal services is a result of a complex and subjective decision‐making process that is unrelated to objective circumstances. The proposed conflict theory model of decision‐making can inform policy and practice regarding the development of appropriate, timely and individualized interventions to facilitate the use of formal services by caregivers of persons with dementia.
In situ adherence of Vibrio spp. to cryosections of Atlantic salmon, Salmo salar L., tissue.
Authors: Knudsen G. , Sørum H. , Press C MC.L. , Olafsen J A.
Published: March 2003

Pathogenic and presumed non‐pathogenic bacteria isolated from fish were tested for their adhesion to cryosections from different mucosal surfaces of Atlantic salmon, Salmo salar L. Adhered bacteria were detected by immunohistochemistry. Mucus was stained and fixed with Alcian blue after incubation of bacteria. The majority of the bacteria tested, i.e. Vibrio anguillarum serotype O1, Vibrio salmonicida, Vibrio viscosus, Flexibacter maritimus and ‘gut vibrios’, i.e. Vibrio iliopiscarius and intestinal isolates of V. salmonicida, all adhered to mucus on all salmon epithelial surfaces tested, including sections from the foregut, hindgut, pyloric caeca, gills and skin. In contrast, V. anguillarum serotype O2, including both serotypes O2a and O2b, did not adhere to mucus, but did adhere to all other components of the tissues. As a positive control for adhesion of bacteria on cryosections, Escherichia coli was bound to piglet ileal mucosal lining, and as a negative control for adhesion, Staphylococcus aureus was found not to bind to any of the tissues tested. The present study shows that adhesion to mucus was not restricted to pathogenic bacteria, and furthermore, that not all pathogenic bacteria studied adhered to mucus. Hence, on the basis of these findings, the present authors suggest that V. anguillarum O2 may have an invasion strategy which does not involve adhesion to mucus, and thus, differs from the other pathogenic bacteria in the present study, which all bound to salmon mucus.
Systemic infection with Uronema‐like ciliates in farmed turbot, Scophthalmus maximus (L.)
Authors: Sterud E. , Hansen M K. , Mo T A.
Published: March 2003

Histophagous ciliates caused high mortality among turbot in a commercial fish farm in southern Norway. The ciliates spread systemically in fry (< 0.3 g). In the early stages of infection the ciliates were found in connective tissue in skin and fins, as well as in nervous tissue. In terminal stages the whole organism was infected. In large turbot (500–1000 g), the ciliates were predominantly found in the central nervous system, causing liquefaction of the nervous tissue. The ciliates were not identified to species but resembled species in the genus Uronema (Scuticociliatida).
Muscle degeneration associated with cotton shrimp disease of Penaeus indicus
Authors: Ramasamy P. , Jayakumar R. , Brennan G P.
Published: March 2003

Microsporidian disease of prawns has generally been recognized by the progressive white opacity associated with the musculature. Such microsporidian‐infected prawns are known as ‘cotton shrimp’, ‘milky white’ or ‘chalky white’ prawns. Microsporidians have been reported from prawns of several genera, notably Penaeus, Pandalus and Crangon (
Sprague & Couch 1971;
Newman, Johnson & Pauley 1976). These diseases are highly pathogenic and cause epizootics in feral crustacean populations (
Iverson & Manning 1959;
Overstreet 1973;
Lightner, Fontaine & Hanks 1975;
Sindermann 1990).
Experimental infection of European crustaceans with white spot syndrome virus (WSSV)
Authors: Corbel V , Zuprizal Z , Shi C , Huang  , Sumartono  , Arcier J‐M , Bonami J‐R
Published: March 2003

Eight European marine and freshwater crustaceans were experimentally infected with diluted shrimp haemolymph infected with white spot syndrome virus (WSSV). Clinical signs of infection and mortalities of the animals were routinely recorded. Diagnosis was by direct transmission electron microscopy (TEM), DNA hybridization (dot‐blot and in situ hybridization) using WSSV probes and by PCR using WSSV specific primers. High mortality rates were noted between 7 to 21 days post‐infection for Liocarcinus depurator, Liocarcinus puber, Cancer pagurus, Astacus leptodactylus, Orconectes limosus, Palaemon adspersus and Scyllarus arctus. Mortality reached 100%, 1 week post‐infection in P. adspersus. When infection was successful, direct TEM observation of haemolymph revealed characteristic viral particles of WSSV, some observed as complete virions (enveloped), others as nucleocapsids associated with envelope debris. WSSV probes showed strong positive reactions in dot‐blots and by in situ hybridization in sections and specific virus DNA fragments were amplified successfully with WSSV primers. White spot syndrome virus was pathogenic for the majority of the crustaceans tested. This underlines the epizootic potential of this virus in European crustaceans.
A biologically active IL‐1β derived peptide stimulates phagocytosis and bactericidal activity in rainbow trout,Oncorhynchus mykiss(Walbaum), head kidney leucocytesin vitro
Authors: Peddie S , Zou J , Secombes C J
Published: March 2003

The present work provides the first information concerning the ability of a rainbow trout interleukin‐1β (IL‐1β) derived peptide, P3, to enhance phagocytosis and bactericidal activity. P3 was synthesized to complex with the IL‐1 receptor and corresponds to fragment 197–206 (YRRNTGVDIS) of the trout sequence. A dose‐dependent effect of P3 on phagocytosis in head kidney leucocytes was documented, with an optimal response occurring at 0.25 mM. With respect to the temporal kinetics of P3 induced activation, an incubation period of 2 h resulted in enhanced phagocytic activity, although incubation times of between 4 and 24 h were optimal. An additive effect was observed when P3 (0.1 mM) was combined with another IL‐1 derived peptide, P1 (0.1 mM). The latter peptide corresponds to fragment 146–157 (YVTPVPIETEAR) and is equivalent to a region in the mammalian protein that is known to be part of the receptor binding domain, but does not overlap with P3. With respect to bactericidal activity, macrophages incubated for 24 h with 0.1 mMP3 demonstrated an enhanced ability to kill an avirulent strain (MT004) of the Gram‐negative salmonid pathogenAeromonas salmonicida. Further investigation revealed that extracellular production of superoxide anions was not responsible for the enhanced bactericidal activity of macrophages exposed to P3.
A balanced approach towards healthy eating in autism
Authors: Cornish E.
Published: March 2003

Background: This audit was undertaken to investigate the dietary intake and food‐related behaviour of children diagnosed within the autistic spectrum continuum. It was hoped to understand the difficulties faced by parents and carers and to offer a holistic service.
Method: Parents of 17 autistic children aged 42–117 months were interviewed and data collected by 3‐day dietary recall and food frequency questionnaire. Weight and height measurements for each child were obtained. South Derbyshire Ethics Committee approval was given.
Results: Nutrient intakes on analysis fell below reference nutrient intake (RNI) levels for 53% (nine) children in one or more of the following nutrients: vitamin C, iron, vitamin D, niacin, riboflavin, vitamin B6, calcium and zinc. One child fell below the lower reference nutrient intake (LRNI) for iron and three children aged under 4 years did not meet the LRNI for vitamin D from dietary sources. Excessive milk consumption in 13 children raised calcium intake to levels above 200% of RNI levels.Conclusion: Eating habits were extremely prescriptive. Food preferences were specific for ‘dry’ or ‘wet’ forms, colour, shaped retail products and even brand packaging. Food refusal and introduction of new foods were cited as the most difficult problems faced by parents. Oral sensitivity, poor oral motor movements and difficult eating behaviours were identified and an integrated service involving dietitian, speech therapist and paediatric clinical psychologist was advocated.
McCance & Widdowson's Tables of Food Composition: origins and clarification of the Fifth edition
Authors: Black A. E. , Paul A. A.
Published: March 2003

The evolution of the McCance and Widdowson's Tables of Food Composition is briefly described and some confusions that exist over the Fifth edition are clarified.
Monoamine oxidase drugs and diet
Authors: Merriman S. H.
Published: March 2003

Aims: To review the literature on monoamine oxidase drugs and propose a simple diet sheet.

Methods: A literature search, using a range of computer data bases and the assistance of the Mental Health Group of the British Dietetic Association.

Results: MAO‐B drugs (e.g. Selegiline) do not require dietary restrictions. MAO‐A drugs and MAOI drugs do require a restriction of the intake of tyramine. The manufacturer (Roche) of Manerix (moclobemide), an MAO‐A drug, states that not more than 50 g of cheese should be eaten when taking that medication. MAOI drugs (e.g. Isocarboxazid (Cambridge), Nardil (P‐D), Parnate (SK & F)) require further dietary restrictions. Patients taking MAOI drugs should not consume more than 6 mg tyramine in a single dose (i.e. a meal or snack).

Conclusion: A simple diet sheet, for use with MAOI drugs, has been devised. It lists the foods which must be avoided, those which may be taken in moderation and those which may be eaten freely.
An assessment of compliance with nutrition criteria and food purchasing trends in Heartbeat Award premises
Authors: Holdsworth M. , Haslam C. , Raymond N. T.
Published: March 2003

Background: The Heartbeat Award scheme (HBA) was initiated in Leicestershire in 1990. An evaluation of compliance of HBA premises with nutrition criteria and an assessment of the impact of the scheme on food purchasing trends has not been previously reported.

Method: Twenty‐three caterers (12 workplaces and 11 public eating places) responsible for implementing the scheme were interviewed to establish the extent to which premises continued to comply with nutrition criteria; whether healthy food choices were being marketed after receiving the HBA; and caterers assessment of food purchasing trends. Data were collected during face‐to‐face interviews using a questionnaire and checklist.

Results: All workplaces complied with 11 of the 34 nutrition criteria, and all public eating places complied with 22 of the 34 nutrition criteria. A quarter of caterers reported not providing one‐third of all menu sections as healthy choices. Three‐quarters of establishments used a symbol to highlight healthy food choices. This was the only form of promotion in most cases. At least a quarter of premises reported an increase in sales of some healthier food items. Even so, the uptake of less healthy choices remained the same in most premises.

Conclusion: The lack of compliance locally with so many nutrition criteria is a major concern. This raises the question of whether scarce dietetic resources are being used appropriately without a system for monitoring.