bluuebunny/crossref_metadata_2025 huggingface dataset:
Methyl orange antagonizes uridine 5′ triphosphate and not α,β‐methylene‐adenosine 5′ triphosphate‐evoked depolarization of rat superior cervical ganglia
Authors: Connolly G. P.
Published: March 2003

1 Compared with the effects of adenosine 5′ triphosphate (ATP) on the nervous system, the actions of pyrimidine nucleosides and their 5′‐nucleotides, such as uridine 5′ triphosphate (UTP), have received less attention. In part, this is because there is a need for a selective antagonist for responses mediated by UTP‐activated receptors. The objective of this study was to discover such an antagonist.

2 Superior cervical ganglia isolated from male rats were superfused with a physiological salt solution. Responses to α,β‐methylene‐ATP (α,β‐Me‐ATP), potassium, adenosine and UTP were determined before and in the presence of 1–300 μM methyl orange.

3 Methyl orange at 1–100 μM did not alter resting potential or depolarizing responses to α,β‐Me‐ATP, potassium, or adenosine‐evoked hyperpolarizations, but at 10 and 100 μM methyl orange significantly antagonized UTP‐evoked depolarizations (P < 0.05).

4 Although the antagonistic effects of methyl orange were not dramatic, this is the first report of a putative pyrimidinoceptor antagonist. These observations also support the idea of distinct receptors for UTP and ATP on rat superior cervical ganglia.
The effect of streptozotocin‐induced diabetes on cardiac β‐adrenoceptor subtypes in the rat
Authors: Sellers D. J. , Chess‐Williams R.
Published: March 2003

1 The present study investigates the effect of short‐term experimental diabetes of 14‐days duration on the β‐adrenoceptor subtypes of the rat heart.

2 β‐adrenoceptor‐mediated functional responses to submaximal doses of isoprenaline were enhanced in Langendorff‐perfused hearts from diabetic rats, manifested as greater changes in tension, heart rate and rates of tension development (+dT/dt) and decline (–dT/dt).

3 Radioligand binding data demonstrated that total cardiac β‐adrenoceptor density and affinity for [3H]‐dihydroalprenolol was unchanged by diabetes, although a decrease in β1‐adrenoceptor density and increase in β2‐adrenoceptor density was observed.

4 In conclusion, hearts from 14‐day streptozotocin‐induced diabetic rats demonstrate a number of alterations within the β‐adrenoceptor system. However, the enhanced β‐adrenoceptor‐mediated responses to isoprenaline were not caused by an overall increase in density of β‐adrenoceptors, but were accompanied by changes in the ratio of the β‐adrenoceptor subtypes.
The effects of adenosine on isolated right atrial preparations from streptozotocin‐diabetic rats
Authors: Usta Co kun , Adan Gülay , Özdem Sadi S.
Published: March 2003

1 The aim of the present study was to investigate the inhibitory effects of adenosine on the contractile force and chronotropic action of isolated right atrial preparations from streptozotocin (STZ)‐diabetic rats.

2 The rats were anaesthetized with diethyl ether and STZ (65 mg kg−1) was injected intravenously via the tail vein.

3 Adenosine produced concentration‐dependent decreases in the force of contraction and a negative chronotropic action of atria both in control and diabetic groups. The inhibition responses to adenosine were significantly higher in diabetic rat atria than control.

4 Dypiridamole incubation caused a significant potentiation of the inhibitory effect of adenosine on contractile force and chronotropic action of atria in the control group, but not in the diabetic group. In the presence of dipyridamole, the inhibitory effects of adenosine on measured parameters in diabetic rats were not significantly different from those in control rats.

5 These results suggested that atria from 6 weeks STZ‐diabetic rats exhibited a supersensitivity to the negative inotropic and chronotropic effects of adenosine compared with atria from control rats because of an impairment in adenosine uptake mechanism. Altered sensitivity to effects of adenosine might reflect relatively early changes in the course of diabetes.
Zoogeography of the coral reef fishes of the Socotra Archipelago
Authors: Kemp J.
Published: March 2003

Fish communities and habitats were studied at the Socotra archipelago (Gulf of Aden, ≈12°N 54°E). Extensive and unexpected hermatypic coral communities were recorded, at the centre of a 2200 km gap in knowledge of species and habitat distributions which coincides with a change from a western Indian Ocean coral reef fauna to an Arabian one. The fish assemblage associated with the Socotra archipelago corals is predominantly south Arabian. An east African influence, minimal on the mainland coasts of Arabia, is more evident here, and results in previously unrecorded sympatry between Arabian endemic species and their Indian Ocean sister taxa. A study of distributions of Chaetodontidae (butterflyfishes) in the north‐western Indian Ocean reveals a number of distinct patterns, with a trend for species replacement along a track from the northern Red Sea to the Indian Ocean. A major feature of the reef fish zoogeography of the region is found to be a distinct south Arabian area, characterized by a ‘pseudo‐high latitude effect’ which results from seasonal cold water upwelling along the Arabian sea coasts of Yemen and Oman and the Indian Ocean coast of Somalia. This south Arabian feature is consistent across a wide range of fish families. It is most pronounced in Oman and Yemen, and although it is the dominant influence at Socotra it is slightly ‘diluted’ here by the east African influence. The south Arabian area wholly or partly accounts for most of the major marine zoogeographic features around Arabia, and is the principal feature fragmenting Arabian coastal fish assemblages, and separating them from those of the wider Indo‐west Pacific.
Water‐energy dynamics, climate, and prediction of woody plant species richness: an interim general model
Authors: O'Brien Eileen
Published: March 2003

Predictable geographic patterns in the distribution of species richness, especially the latitudinal gradient, are intriguing because they suggest that if we knew what the controlling factors were we could predict species richness where empirical data is lacking (e.g. tropics). Based on analyses of the macro‐scale distribution of woody plant species richness in Southern Africa, one controlling factor appears to be climate‐based water‐energy dynamics. Using the regression models of climate's relationship to species richness in Southern Africa, I was able to describe an Interim General Model (IGM) and to predict first‐order macro‐scale geographic variations in woody plant species richness for the continent of Africa, as well as elsewhere in the world—exemplified using South America, the United States and China.

In all cases, the geographic pattern of variation in species richness is in accord with geographic variations in vegetation (visual comparison with vegetation maps) and net primary productivity. What validation was possible (Africa and U.S.A.) suggests that the IGM provides ‘reasonable’ estimates for actual woody plant species richness where species richness is in relative equilibrium with climate. Areas of over‐ or under‐prediction support the contention of earlier workers that edaphic, topographic, historical, and dispersal factors need to be considered in a more complete explanation for spatio‐temporal variations in species richness.

In addition to providing a means for systematically estimating woody plant species richness where present‐day empirical data is lacking, the Interim General Model may prove useful for modelling the effects of climate change (past/future) on species richness (and, by association, the vegetation).
Relationships between geographical range size, body size, local abundance, and habitat breadth in North American suckers and sunfishes
Authors: Pyron Mark
Published: March 2003

AimI examine the relationship between geographical range size and three variables (body size, an index of habitat breadth, and an index of local abundance) within a phylogenetic framework in North American species of suckers and sunfishes.

LocationNorth America

MethodsRegressions after independent contrasts of geographical range size, body size, habitat breadth, and local abundance.

ResultsSpecies with large range sizes tend to be larger‐bodied, be more locally abundant, and have higher habitat breadths. Character reconstructions support the prediction that variables associated with rarity (small geographical range size, low local abundance, low niche breadth, and large body size) evolve in unison, although large body size was associated with the opposite traits in these taxa.Gaston & Blackburn (1996a)suggested using visual identification of the lower boundary of the geographical range‐body size relationship to identify extinction‐prone species; this resulted in thirteen species that are potentially extinction‐prone.

Main conclusionsSimilar evolutionary mechanisms appear to operate on body size and other variables related to rarity, even in distantly related taxa.
Seals and seascapes: covariation in Hawaiian monk seal subpopulations and the oceanic landscape of the Hawaiian Archipelago
Authors: Schmelzer Isabelle
Published: March 2003

Aim

The possible linkages between the spatial distribution of primary productivity over the north‐western Hawaiian islands and trends of subpopulations of Hawaiian monk seals in the period 1956–1995 were assessed. This endangered seal is endemic to the north‐western Hawaiian islands (NWHIs), where about 1300–1400 individuals are distributed among six main breeding subpopulations. A striking property in patterns of abundance among subpopulations is their spatial nature, a feature suggesting that these may be related to variation in the biotic marine environment. In examining linkages between trends in abundance at these subpopulations and the marine habitat of the NWHIs, an understanding of the relative importance of intrinsic or extrinsic regulatory processes to the long‐term dynamics of the seal can be gained.

Location

The north‐western Hawaiian islands (Hawaiian Archipelago).

Methods

Productivity of the seascape was mapped using both remotely sensed images and data collected during oceanographic cruises. Measurements included sea surface temperature (SST), vertical water column structure, integrated chlorophyll, and their respective levels of variability. The spatial structure and heterogeneity of both mean values and coefficients of variation of these variables were quantified statistically by calculating descriptive statistics for each block of a 20° × 10° grid (with 200 blocks of dimensions 1°) overlain on each map, and computing spatial statistics for each variable (based on the summary statistics calculated for each block). Multivariate techniques were used to identify biogeographical regions within the pelagic landscape of the NWHIs. Monk seal trends among breeding sites within and among biogeographical regions were compared by analysing correlations among mean beach counts for each subpopulation.

Results

Primary productivity over the marine habitat of the Hawaiian monk seal was found to be non‐uniform. A significant spatial pattern of primary productivity over the NWHIs, most apparent in a gradient along latitudinal lines, was documented. Multivariate groupings of environmental data partitioned the NWHIs into distinct biogeographical regions, and Hawaiian monk seal breeding areas can be differentiated on the basis of these. Regions with similar environments displayed synchronous variation in monk seal abundance.

Main conclusions

These findings suggest the local trends in monk seal abundance have ultimately been shaped by the quality of the surrounding marine environment. In assessing the dynamics of the Hawaiian monk seal as a whole, and notwithstanding the short‐term and local effects of proximate mortality factors, extrinsic, ecosystem‐level mechanisms appear to be important in shaping the long‐term population dynamics of this endangered mammal. If that is the case, then environmental variation may also be an important determinant of the potential for recovery of these subpopulations and therefore for the entire species.
Centrifugal speciation and centres of origin
Authors: Briggs John C.
Published: March 2003

Aim

To discuss the development and usefulness of the theory of centrifugal speciation and its practical application to the centre of origin hypothesis.

Location

The Indo‐West Pacific Ocean.

Methods

Utilization of patterns demonstrating species diversity, generic age, dispersal tracks, phylogenetics, extinction and genetic diversity.

Results

The centrifugal speciation hypothesis appears to provide a suitable explanation for the way in which centres of origin theoretically operate. Recent information about the centre of origin in the marine East Indies suggests that it is the source of evolutionary radiation for the Indo‐West Pacific. Its mechanism appears to conform to the centrifugal prediction.

Main conclusions

The East Indies Triangle is the origin of a series of dynamic systems that extend across the entire Indo‐West Pacific. These systems are apparently maintained by a continuous outflow from the centre of origin. A series of species replacements from the East Indies over the past 10 million years would create and perpetuate the systems that have been identified.
Acacia species turnover in space and time in an African savanna
Authors: Bond William J. , Smythe Keri‐Ann , Balfour Dave A.
Published: March 2003

Aim

Patterns of species turnover along environmental gradients are better studied than their causes. Competitive interactions, or physiological tolerance are most often cited as determinants of turnover. Here we investigate differential tree species response to disturbance by fire and mammal browsing as causes of changing dominance of species within and among sites along an altitudinal gradient.

Methods

We documented the distribution of two Acacia species using maps and sample transects. We explored possible causes of species turnover by studying differences between the species in tolerance to grass competition using pot experiments, to browsers by observing patterns of shoot damage, and to fire by comparing the size structure of populations burnt at different frequencies and intensities.

Results

Acacia karroo woodlands were rare and occur at higher elevations than the much more common A. nilotica woodlands. Woodland composition seems set to change in future since the pattern of dominance was reversed in juvenile stages. A. karroo juveniles were very widespread and far more abundant than A. nilotica juveniles. A. karroo juveniles were most abundant in tall fire‐prone grasslands and were rare on grazing lawns whereas A. nilotica showed the reverse pattern. In the pot experiments, growth of both species was suppressed by grasses but there were no significant differences in response between the two species. Juveniles of A. karroo were more heavily browsed than those of A. nilotica. However juveniles of A. nilotica were less tolerant of frequent intense burns than juvenile A. karroo.

Main conclusions

Disturbance gradients, from high fire frequency and low herbivore density at high altitudes, to lower fire frequency and higher herbivore density at low altitudes, are responsible for the shift in community structure along the spatial gradient. Differential responses to browsing and fire may also explain temporal turnover from A. nilotica in the past to A. karroo in the present. Changes in the area burnt annually, and in faunal composition, suggest a landscape‐scale shift from grazing‐dominated short‐grass landscapes in the 1960s, favouring A. nilotica, to fire‐dominated tall grasslands in the 1990s favouring A. karroo. We suggest that species turnover due to differential responses along disturbance gradients may be much more widespread than the current paucity of studies suggests.
Geographical abundance distributions of coastal invertebrates: using one‐dimensional ranges to test biogeographic hypotheses
Authors: Sagarin Raphael D. , Gaines Steven D.
Published: March 2003

Aim

It is often assumed that species generally reach their highest densities in the centre of their range and decline in abundance towards the range edges. A number of mechanisms have been proposed that could theoretically support this pattern, and several ecological theories have been developed based on the assumption that this pattern occurs in nature. However, few studies have quantified geographical patterns of species abundance throughout species ranges. This is largely because of the logistical challenges of sampling throughout the large spatial areas of most species ranges. We use intertidal invertebrates, which have relatively well defined linear ranges, to test the hypothesis that species are most abundant in the centres of their ranges.

Location

Our sampling programme covered all or most of the ranges of twelve intertidal invertebrate species along the Pacific coast of North America, from Cabo San Lucas (Baja California, Mexico) to Shelikof Island (AK, USA).

Method

We sampled invertebrate density at forty‐two field sites using quadrat and transect methods. We used a shape fitting procedure to find idealized range shapes that best fit the sampled distributions of abundance. The idealized range shapes represented both a distribution where abundance was highest at the range centre and distributions where abundance was highest at one or both of the range edges.

Results

Overall, this suite of species did not show the expected pattern of high abundance near the range centre. Six of the species showed patterns indicative of high densities near one of their range edges, whereas only two showed patterns with high densities near their range centres. Furthermore, nine of the twelve species had sites near the range edges in which density ranked in the top 20% of all sites.

Main conclusions

The hypothesis that species are most abundant in the centre of their ranges cannot be generalized to this diverse suite of intertidal organisms. The diversity of distribution shapes that we found suggest that evolutionary and ecological theories that assume high abundance at range centres should be re‐examined with consideration of alternative abundance distributions. We suggest that sampled geographical distributions of abundance can be combined with demographic and physical factor data taken at the same scale to test hypotheses related to the causes of range boundaries and the responses of species ranges to climatic change.
Humans, fire and landscape pattern: understanding a maquis‐forest complex, Mont Do, New Caledonia, using a spatial ‘state‐and‐transition’ model
Authors: Perry George L. W. , Enright N. J.
Published: March 2003

Abstract Aim  The research explores how changes in disturbance regime resulting from human settlement may affect landscape structure. A spatially explicit grid‐based simulation model is used to explore the interplay between humans, fire regime and landscape composition.

Location  The study site for this research is the botanical reserve at Mont Do, New Caledonia. The endemic conifer Araucaria laubenfelsii (Araucariaceae) forms a key component of the landscape at Mont Do. This species is unusual in that it is found scattered as an emergent in maquis and as a canopy species in adjacent rain forest patches. Although now dominated by a low maquis, prior to human settlement of New Caledonia, montane landscapes such as Mont Do are likely to have been heavily forested.

Methods  A spatially explicit simulation model, based on field data and palaeoecological information, was used to explore interactions between disturbance regime and the landscape. The model is described briefly here and more fully in Perry & Enright (2002) Ecological Modelling, 152, 279.

Results  The model suggests that human‐influenced changes to the fire regime at Mont Do have been important in generating the current landscape structure. The origin and maintenance of forest landscapes and maquis‐forest mosaic landscapes are considered in the context of alternative stable states. Strong feedback loops between fire size and landscape composition, mediated at the smaller scale by other similar mechanisms, are capable of driving landscape change. The utility of a spatial state and transition modelling approach is demonstrated.

Main conclusions  The current landscape pattern on Mont Do is likely the result of changes to the fire regime occurring since human settlement. The specific mechanisms for this change outlined here may occur in a number of other similar systems. Understanding the origin and persistence of these ‘fire landscapes’ in New Caledonia and in the south‐west Pacific in general is crucial for their effective management.
The primary/secondary interface. Cross‐boundary teamwork — missing link for seamless care?
Authors: Hibberd Patricia A.
Published: March 2003

• Factors for providing a seamless service are given and it is suggested that more collaborative interactions between organizational groups are needed to achieve this.

• It is argued that competitive philosophy within the NHS has been prohibitive to seamless care. Elements of the White Paper (DoH, 1997) are discussed in relation to this. Features of a collaborative organization are briefly discussed.

• Three current ‘models’ of cross‐boundary interaction at the point of patient transfer are discussed.

• A fourth model involving enhanced inter‐sector teamwork with multidisciplinary membership and shared professional, management and patient/carer responsibility is proposed.
Manual handling: what patient factors do nurses assess?
Authors: COOK GLENDA , NENDICK CHRIS
Published: March 2003

• Since 1990, the philosophy of `safe lifting' has become unacceptable in clinical practice and it is now recommended that nurses do not manually lift patients at all.

• A comprehensive moving/handling assessment should be undertaken and should include assessment of the handler's capability as well as the load (patient), task and environment.

• This exploratory study focuses on assessment of the load, aiming to identify the patient variables nurses assess when planning moving/handling requirements of adult patients.

• Patient variables were identified from a literature review and provided the base for a semistructured postal questionnaire.

• Questionnaire responses were subjected to a Principal Component Factor analysis resulting in extrapolation of 5 factors accounting for the majority of variability in the data.

• In addition, a further 33 new patient variables were reported to be important in this type of assessment.

• Issues for further investigation are highlighted and implications for teaching moving/handling risk assessment are drawn from the findings.
Implementation of risk assessment and classification of pressure ulcers as quality indicators for patients with hip fractures
Authors: GUNNINGBERG LENA , LINDHOLM CHRISTINA , CARLSSON MARIANNE , SJÖdÉn PER‐OLOW
Published: March 2003

• The aims of the study were (i) to investigate the prevalence of pressure ulcers in patients with hip fracture, on arrival at a Swedish hospital, at discharge, and two weeks post‐surgery; (ii) to test whether clinical use of the Modified Norton Scale (MNS) could identify patients at risk for development of pressure ulcers; and (iii) to compare the reported prevalence of pressure ulcer in the experimental group, where risk assessment and classification of pressure ulcers was performed on a daily basis, with that of the control group, where it was not.

• The study design was prospective, with an experimental and a control group. The intervention in the experimental group consisted of risk assessment, risk alarm and skin observation performed by the nurse on duty, in the A & E Department, and daily throughout the hospital stay.

• To facilitate the nurse's assessment, a `Pressure Ulcer Card' was developed, consisting of the MNS and descriptions of the four stages of pressure ulcers.

• On arrival at the hospital, ≈20% of patients in both groups had pressure ulcers. At discharge, the rate had increased to 40% (experimental) and 36% (control).

• Clinical use of the MNS made it possible to identify the majority of patients at risk for development of pressure ulcers. Patients who were confused on arrival developed significantly more pressure ulcers than patients who were orientated to time and place.

• No significant difference was found in the reported prevalence of pressure ulcers between the experimental and control groups.
Developments in nursing practice in primary health care in Hong Kong: opportunities and challenges
Authors: Twinn Sheila
Published: March 2003

• The significance of primary health care to the health of individuals and communities has been well established but the development of primary health care and nursing practice within the context of primary health care remains varied in different countries and settings.

• This paper focuses on developments in nursing practice in primary health care in Hong Kong, using three community‐based research projects to identify the opportunities and challenges created for nurses working in these settings. The projects were established in response to identified health needs and to target cancer education, HIV/AIDS and chronic health problems.

• Opportunities include the development of professional autonomy, innovative approaches to clinical practice, and developing skills in working with a diverse range of professionals and communities. Challenges include managing uncertainty and the development of evaluation systems to demonstrate health gains from nursing interventions.
Documenting diabetes care: the diabetes nurse specialists' perspective
Authors: Thompson Kathryn A. , Coates Vivien E. , Mcconnell Cassandra J. , Moles Kenneth
Published: March 2003

•  Diabetes Nurse Specialists (DNSs) are often the hub of the communications network for the entire diabetes multiprofessional health care team, patients and their families. Frequently they liaise between primary and secondary care and have a key role in the provision of a ‘seamless service’. To work effectively and efficiently they need a foolproof system of documentation and communication.

•  The aim of the study was to investigate the means by which DNSs document patient care in order to provide baseline information about ongoing record‐keeping practices.

•  The study comprised a cross‐sectional survey in which data were obtained by questionnaire. All DNSs in the UK registered with the British Diabetic Association were invited to participate in the study. A 70.3% response rate was achieved (n = 545).

•  The results indicated that manual profession‐specific records were used by 65.3% of DNSs, 21.1% used shared/integrated records, 12.8% used computerized records and only 0.7% made use of patient‐held records. Whilst almost all DNSs felt that a good record‐keeping system was essential in providing ‘seamless care’ to patients, not all felt their system was efficient. Of those using a computerized system 65.7% rated it as efficient, compared with only 28.1% of those using a profession‐specific system and 26.1% of those using a manual shared system.

•  A high percentage of DNSs (65.9%) felt that the provision of ‘seamless care’ was hindered by communication problems with members of other professional groups.

•  The findings from this study indicate that computers alone cannot bridge the gap between primary and secondary care, but ‘seamless care’ may become more of a reality with computerized record‐keeping systems and participation by all members of the multidisciplinary team.
Selectively living in the past: nostalgia and lifestyle
Authors: Lyon Phil , Colquhoun Anne
Published: March 2003

Abstract: It is something of an understatement to speak of the UK, and many similar societies, as being obsessed with the mastery of time. From hesitant beginnings in the transformation of production processes and the development of mass transportation systems, the need to co‐ordinate activities in time, and accomplish tasks with ever greater speed, has permeated virtually all aspects of everyday life. Many goods and services are sold on the basis of speed, efficiency or explicitly in terms of how much time they can save us. The specific characteristic of speed becomes the master variable on which we distinguish between brands and judge the progress made by manufacturers or providers. Using food as one example of this phenomenon, we can see the congruity of fast food, microwaveable frozen products, pizza deliveries to your door, street grazing and the fragmentation of family meal occasions. Set against this is an apparent counter‐tendency to imbue the past – when things were slower – with particular symbolic value. Traditional becomes a metaphor for high quality; a description of ingredients and processes that were in more generous measure than could be expected today. In this, it also serves as an implicit justification for price premiums. Again, using food as an example, products and packaging often make liberal use of the imagery of yesteryear, the farm, the country kitchen, allusions to fresh or natural ingredients and old‐fashioned ways of doing things. In this article, we examine the paradoxical relationship with time which seems increasingly commonplace in the final years of this century and draw on a wide range of secondary source materials to demonstrate this. It is argued that nostalgic1 products and leisure practices can be understood not as an irrational, even pathological, reflection of longing for the past but as a coping strategy for the contradictions. Given the centrality of consumer behaviour and social patterns to the field of home economics, there is a need to reflect the issue in teaching and research.
Factors influencing size inequality in peatland black spruce and tamarack: evidence from post‐drainage release growth
Authors: Macdonald S. Ellen , Yin Fengyou
Published: March 2003

1 We used tree ring analysis to determine stem radius and thus examine size variation over time in two even‐aged (approximately 40‐year‐old) mixed populations of black spruce and tamarack established on peatlands in a boreal forest. We also followed the response of one of these populations to improved edaphic conditions over 8 years following drainage.

2 Populations of trees in undrained areas showed a decline in size variability over time until age 20–25 years, after which size heterogeneity was relatively stable.

3 For trees in undrained areas there was a relationship between age and size for the first 20–25 years, but this relationship then broke down due to a period where relative growth rate and size were inversely related.

4 For the population of trees in the drained area, smaller trees (i.e. those that had been growing more slowly prior to drainage) showed significantly greater drainage‐induced release growth, while larger trees (those growing faster prior to drainage) showed an initial reduction in growth following drainage and, overall, less release growth.

5 The response of tamarack to drainage was more dramatic than for black spruce.

6 Despite extensive variation in tree size, drainage dramatically reduced variability in growth rate among trees of each species, such that size variability in the populations declined.

7 We postulate that the heterogeneity of microsites with respect to edaphic conditions, perhaps associated with the hummock to hollow microtopographic gradient, has a major influence on growth variation, and hence size inequality, in peatland populations of black spruce and tamarack.
The combined effects of scale and productivity on species richness
Authors: Weiher Evan
Published: March 2003

1 Although species–area curves are well documented, we know little about how they vary along productivity gradients, nor do we have a firm understanding of whether the richness–productivity relationship is independent of scale. In order to investigate these relationships, 10 species–area curves were constructed for 10 sets of nested quadrats (from 0.25 m2 to 150 m2) in herbaceous marshes where biomass ranged from 128 g m–2 to 1050 g m–2.

2 Slopes (z) of the species–area curves (logS = logc + zlogA) were positively correlated with production (whether measured as biomass or soil organic content). A possible cause of increased slope was larger potential species pools at high biomass. The constants (c) were negatively associated with production, which concurs with the general richness–productivity relationship.

4 Linear models were used to predict both c and z using biomass and soil organic content. Biomass explained about 38% of the variation in both z and logc. Soil organic content was a better predictor. It explained 60% of the variation in z and 41% of the variation in c.

5 The slopes (z) and constants (c) of the species–area curves were negatively correlated. Because c is the expected species richness at 1 m2 and z strongly affects larger‐scale richness, the results suggest that small‐scale richness is not a good indicator of larger‐scale richness. There was no significant relationship between species richness in small‐scale (0.25 m2) quadrats and large‐scale quadrats (150 m2).

6 These results suggest that the conflicting data that have led to recent debate over the richness–productivity relationship may reflect both the effects of scale and the natural history peculiarities of the systems studied.
Errors: can indicators measure the magnitude?
Authors: Kazandjian Vahé A. , Matthes Nikolas , Thomas Tom
Published: March 2003

Errors in medicine, especially medication errors, have long been recognized as a dimension of quality of care and organizational performance. Recently, however, the magnitude of the issue, or its potential impact on cost, quality of care and patient safety have catapulted this issue to the forefront of national debate on the appropriateness of patient care management. There are still fundamental issues associated with the measurement of errors. Should errors that do not cause patient harm receive much attention? Could there be organizational or system issues that predispose to errors? Are there acceptable measurement models that allow comparative analysis and trending of institutional error rate profiles? This paper presents a systematic review of the measurement aspects for errors in medicine, emphasizing the medication errors’ dimension. An indicator‐based, epidemiological model of measurement is proposed which will allow a systematic inquiry into the issues of both preventable and non‐preventable errors and their potential for patient harm.
An illustrated guide to the methods of meta‐analysis
Authors: Sutton Alexander J. , Abrams Keith R. , Jones David R.
Published: March 2003

Meta‐analysis is now accepted as a necessary tool for the evaluation of health care. Such analyses have been carried out in virtually every area of medicine to evaluate a wide spectrum of health care interventions and policies. This paper has three broad aims: (1) to describe the basic principles of meta‐analysis, using a meta‐analysis of interventions intended to reduce hospital re‐admission rates for illustration; (2) to consider threats to the internal validity of meta‐analysis, and the measures which can be taken to minimize their impact; and (3) to present an overview of more specialist and developing methods for synthesizing data, with the intention of outlining the directions meta‐analysis may take in the future. The methods used to synthesize studies, which take ‘weighted averages’ of effect sizes have been refined to a high degree, while the methods for dealing with threats to the validity of meta‐analyses such as publication bias, and variations in quality of the primary studies, are at a less advanced stage. However, many consider this standard ‘weighted average’ approach to meta‐analysis not to be ‘state of the art’ in at least some situations, where the use of more sophisticated methods, generally to explain variation in estimates from different studies and synthesize a broader base of evidence, would be advantageous. Currently, approaches which attempt to do this are mainly still in the experimental stage and, unfortunately, ideas which sound natural and appealing are often difficult to implement in practice. Clearly, it will be some time before they are used routinely, but significant steps have been made.
Structuring student learning in the primary care setting: where is the evidence?
Authors: Kurth Rebecca J. , Irigoyen Matilde M. , Schmidt Hilary J.
Published: March 2003

Over the past two decades, the majority of medical schools in the USA have embarked upon curricular initiatives to enhance the teaching of ambulatory or office‐based primary care. Identifying characteristics of these primary care experiences that make for the most effective learning is a top priority in medical education research. In this paper we examine what is known about the influence of variability in the structure of primary care experiences on student learning outcomes. We examine the questions of how rotations are scheduled, who does the teaching and where the teaching takes place. Given the variability in curricula across the 125 accredited medical schools in the USA and the absence of agreed‐upon objectives, outcomes or assessment measures for primary care education, it is not surprising that the current literature has fallen short in providing definitive answers. There is much debate about the benefits of community vs. campus sites, longitudinal vs. block experiences, and the influence of specialty training of the preceptor, but little in the current literature to guide and substantiate a programme's choice. What can be concluded with relative confidence is that clinics currently offer more active student experiences than do private offices, that students may be more satisfied with rural experiences than with urban or suburban experiences, and that longitudinal and block experiences have different learning advantages. Research in primary care medical education will benefit from the current movement towards a cross‐institutional consensus on educational objectives and outcome measures and on the general application of a more rigorous research methodology.
Applying Prochaska’s model of change to needs assessment, programme planning and outcome measurement
Authors: Parker Kathryn , Parikh Sagar V.
Published: March 2003

A major goal of continuing medical education (CME) is to enhance the performance of the learner. In order to accomplish this goal, careful consideration and expertise must be applied to the three primary ingredients of CME planning: assessing learner needs, programme design and outcome measurement. Traditional methods used to address these three components seldom result in CME initiatives that change performance, even in the presence of sophisticated CME formats and capable learners. In part, performance may not change because the learner is not ‘ready to change’. Planners of CME are aware of this concept but have been unable to measure ‘readiness to change’ or employ it in assessing learner needs, and planning and evaluating CME. One theory that focuses on an individual’s readiness to change is Prochaska’s model, which postulates that change is a gradual process proceeding through specific stages, each of which has key characteristics. This paper examines the applicability of this model to all components of CME planning. To illustrate the importance of this model, this paper provides examples of these three components conducted both with and without implementation of this model.
Improving general practitioner records in France by a two‐round medical audit
Authors: Brami Jean , Doumenc Michel
Published: March 2003

Rationale, aims and objectives The effectiveness of clinical audits in
changing the practice of health care professionals is a moot point. Methods of implementation
impinge directly upon outcomes. We investigated whether a network of local opinion
leaders could contribute towards a successful audit. Our objectives were to: (i)
bring about an improvement in record keeping in general practice; and (ii) increase
GPs’ awareness of medical evaluation. Methods The GPs were recruited
by local opinion leaders who had been briefed by the French National Agency for Accreditation
and Evaluation in Health Care (ANAES, formerly ANDEM). On a given day (first round
of the audit) they were invited to examine whether the medical records of their 10
first patients met 13 set criteria. Overall results were analysed by ANAES. Each
GP was informed of how well they had fared compared with the regional and national
averages and was provided with a standard set of recommendations. Anonymity was ensured
by the local leaders. A second round was conducted 6 months later. Results A
total of 244 GPs took part in both rounds of the audit; 32 dropped out after the
first round. Their results were of a significantly lower standard. A significant
improvement in results (P < 0.025) was recorded between the
two rounds for all 13 criteria of the questionnaire. Overall scores improved between
the two rounds for 69% of the GPs and improved above average for 49%.
The greatest scatter in results was noted for items relating to medical history rather
than to personal identity (administrative data). Conclusions Self‐assessment can help improve general standards of medical record keeping. A network of local opinion leaders, briefed by a national agency whose mission is to promote quality improvement in health care, seems to be an effective means of inducing participation in self‐assessment.
The efficacy of emamectin benzoate as an oral treatment of sea lice, Lepeophtheirus salmonis (KrÒyer), infestations in Atlantic salmon, Salmo salar L.
Authors: Stone J. , Sutherland I. H. , Sommerville C. S. , Richards R. H. , Varma K. J.
Published: March 2003

The efficacy of emamectin benzoate as an oral treatment of sea lice, Lepeophtheirus salmonis (KrÒyer), infestations in Atlantic salmon, Salmo salar L., was evaluated in a dose titration study and two dose confirmation studies. Replicated groups of salmon with induced infestations of sea lice were given emamectin benzoate on pelleted feed at doses of 0, 25, 50 and 100 μg kg−1 biomass day−1 for seven consecutive days. Sea lice were counted at 7, 14 and 21 days from the start of treatment, and comparisons made with control fish given the same diet without emamectin benzoate. Total numbers of sea lice were significantly reduced at all doses in all three studies when compared to control fish. There was no significant difference between doses of 50 and 100 μg kg−1, but the 50 μg kg−1 dose resulted in significantly fewer lice than the 25 μg kg−1 dose. Emamectin benzoate was highly effective in reducing numbers of preadult and adult lice and prevented the maturation of chalimus to motile stages. The optimum therapeutic dose was selected as 50 μg kg−1 day−1 for seven days. Treatment reduced the incidence of epidermal damage by sea lice and, in one study, survival of treated fish was 48% higher than in control groups. No fish mortalities or adverse effects were attributed to treatment with emamectin benzoate at any of the doses tested.
Confirmation of catfish, Ictalurus punctatus (Rafinesque), mortality from Microcystis toxins
Authors: Zimba P V , Khoo L , Gaunt P S , Brittain S , Carmichael W W
Published: March 2003

Unexplained deaths of pond‐grown catfish have occurred for many years. At least some of these mortalities could be from cyanobacteria toxins ingested during feeding on floating diets or passively assimilated through gills during breathing. Recently we were able to document algal production and subsequent ingestion of these toxicants by catfish during a mortality event. The causative organism, Microcystis aeruginosa, was the dominant species within the phytoplankton community during the cooler autumn‐winter season. Pond conditions included a drop in water temperature by c. 5 °C during the 10 days preceding the fish mortalities. Microcystin‐LR, a hepatotoxin produced by Microcystis, was detected in water samples and in catfish liver tissue. Fish exposed to pond water containing this toxic bloom were killed within 24 h. Necropsy of fish revealed congested liver and spleen tissues. The combination of clinical signs, detection of microcystin LR in water and in liver, and death of fish exposed to pond water supports the diagnosis of microcystin toxicosis. More research is needed to identify specific environmental conditions initiating toxin production to model and predict occurrence of these toxic algal blooms.
The effect of anti‐Paramoeba antibodies on Paramoeba sp., the causative agent of amoebic gill disease
Authors: Zilberg D , Munday B L
Published: March 2003

The effect of anti‐Paramoeba antibodies produced in sheep on Paramoeba sp., the causative agent of amoebic gill disease (AGD), was tested. Incubation of Paramoeba sp. with antiserum at a concentration of 20% or more effectively coated the Paramoeba with antibodies. The antiserum had no effect on Paramoeba sp. survival in vitro or on its ability to cause AGD in Atlantic salmon.
Nutrient intakes during pregnancy in a cohort of nulliparous women
Authors: Mathews  , Neil
Published: March 2003

Background: This study investigated dietary intake in a large cohort of pregnant women. There are few data available on the diets of British pregnant women, and no study has previously compared the intakes of pregnant women, from both food and all sources, with those of non‐pregnant women or with the current dietary reference values.
Methods: Dietary information was collected from 774 pregnant nulliparous women in the early stages of pregnancy as part of the Prospective Study of Nutrition, Smoking and Pregnancy Outcome. Subjects completed 7‐day semiquantitative food diaries, which were converted into nutrient values using the COMP‐EAT 4 nutritional system.
Results: Reference nutrient intake values were achieved by over 65% of the cohort for the nutrients investigated, except for vitamin D, folate, iron and selenium, where there was a considerable shortfall even after taking into account use of nutrient supplements.
Conclusion: The dietary intake of the pregnant women in this study appears to be very similar to that of non‐pregnant women in the Dietary and Nutritional Survey of British Adults.
Fitting dietary advice for oral health into the roles of food for elderly, mentally ill people
Authors: Fiske J. , Zhang W.
Published: March 2003

Aim: To identify the roles of food in a day‐centre for elderly, mentally ill people, so that dietary recommendations for optimal oral health are made within the overall philosophies of the day‐centre.

Method: A qualitative approach was adopted. It comprised an observational study of the daily routine and a semistructured interview to examine the attitudes, beliefs and knowledge of the care‐staff related to diet, general health and oral health.

Results: The use of food was pivotal to the functioning of the centre. Food was used for nutrition, as a focus for communal activities, to express love and caring, and to maintain cognitive, daily living and social skills. All staff considered oral health important and appreciated the link between oral health, general health and diet (primarily sugar consumption). Despite this, one‐third of carers considered tooth loss an inevitable consequence of ageing. Sugar was generally regarded as detrimental to general health, but attitudes towards use of sweeteners as an alternative were mixed. However, it was believed that elderly people can adapt to dietary changes.

Conclusion: Dietary advice for oral health would be acceptable if put in the context of general health and the changes take account of the overall philosophies of the centre. To this end a ‘Healthy Eating Resource Pack’ was produced for use in the centre.