bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allometry and plasticity of meristem allocation throughout development in Arabidopsis thaliana
Authors: Bonser Stephen P. , Aarssen Lonnie W. 
Published: March 2003

Summary

The three principal fates of axillary meristems in flowering plants are branching or vegetative growth, reproduction, and inactivity. We examined the relationship between allocation to each of these fates and plant size in five genotypes of Arabidopsis thaliana. Nutrient availability was used to obtain a range of plant size.
Allocation to each meristem fate was recorded at weekly intervals throughout development and at final developmental stage.
There were significant allometric relationships between meristem allocation and plant size for each meristem fate throughout development in each genotype. Allometry and plasticity tended to be strongest early in development. In addition, although there were differences in allometry between genotypes, meristem allocation through development was generally consistent across genotypes.
We interpret the results of this study as an adaptive response to nutrient availability. Increased allocation to growth meristems in high nutrient treatments early in development should maximize both size and the total number of meristems that can be committed to reproduction later in development. This suggests that the pattern of meristem allocation is a component of an adaptive strategy through development in Arabidopsis thaliana.
Habitat and successional status of plants in relation to the communities of their leaf‐chewing herbivores in Papua New Guinea
Authors: Lepš Jan , Novotný Vojtěch , Basset Yves 
Published: March 2003

Summary The spatial distribution of 30 woody species (15 species each of Euphorbiaceae and Moraceae) and their associated leaf‐chewing communities (Orthoptera, Phasmatodea, Coleoptera and Lepidoptera) were studied in coastal, riverine and rain forest habitats. A successional series, from abandoned gardens to primary forest, was examined. Host plant records for more than 27 000 insects, all verified by feeding experiments, and spatial distribution of almost 9000 plant specimens were evaluated. Phylogenetic (taxonomic) relatedness of host plants explained 56% of the variability in the composition of their herbivore communities, while the ecological (distribution) similarity of plants explained only 4%. The successional optimum of plant species was not an important determinant of the composition of their herbivore communities. Neither plant successional optimum nor plant palatability to a generalist herbivore were correlated with the number of species, abundance or host specificity of its herbivores, nor was there a correlation between a plant’s palatability to a generalist herbivore and its successional optimum. Herbivore communities became dominated increasingly by a few abundant species in later stages of succession. On average,Ficusspecies had lower palatability and supported more species of herbivores than species of Euphorbiaceae. The abundance of herbivores and their dominance index were not significantly different between the two plant families. These results contradict several previous studies of successional trends in temperate regions. Many tropical successions, however, start with pioneer trees, rather than with annual herbs, and may present a permanent and predictable habitat for insects even at the earliest stages, with no advantage for polyphagous species. Numerous pioneer trees in the tropics possess anti‐herbivore defences, resulting in their low palatability to generalists, increased host specificity of herbivores, and often idiosyncratic composition of herbivore communities. Even plant traits such as species richness of their herbivores or palatability may have a phylogenetic component which should not be ignored.
Persistence of coastal spruce refugia during the Holocene in northern New England, USA, detected by stand‐scale pollen stratigraphies
Authors: Schauffler Molly , Jacobson George L. 
Published: March 2003

Summary1 Pollen data from wet, forested hollows in five spruce (Picea) stands on the eastern coast of Maine, USA, reveal that spruce has been well‐established (spruce pollen > 6%) for at least 5000 years at four of the sites (Isle au Haut, Schoodic Peninsula, and Roque Island). Spruce became dominant in the fifth stand (Blackwoods, Mount Desert Island) only in the last 2000 years. This is in contrast to pollen stratigraphies from two inland forest hollows and from inland lakes that indicate a significant region‐wide increase in the abundance of spruce only 1000 years ago.2 All five coastal pollen stratigraphies suggest that conditions along the east coast of Maine became cooler and moister sometime between 6000 and 5000 years ago. Mid‐Holocene changes in vegetation and sediment accumulation correspond with the timing of rapid increases in tidal amplitude and diurnal mixing of cold water in the Gulf of Maine, suggestive that these resulted in increased marine effects on the local climate at a time that was generally warmer than present.3 Two inland forest‐hollow stratigraphies do not show evidence of mid‐Holocene cooling. Coastal effects therefore persisted for several thousand years despite regional climate changes.4 The pollen data suggest that refugia along the coast (and probably in isolated sites inland), may have played a critical role in allowing the rapid regional expansion of spruce around 1000 years ago. The steep increases in the abundance of spruce pollen in all forest‐hollow and lake pollen stratigraphies in northern New England at that time corroborate other evidence of a region‐wide shift to cooler and moister conditions.5 Pollen stratigraphies from small forested hollows provide a means to examine local vegetation dynamics and interpret those dynamics in the context of regional signals.
Why does fertilization reduce plant species diversity? Testing three competition‐based hypotheses
Authors: Rajaniemi Tara K. 
Published: March 2003

Summary1 Plant species diversity drops when fertilizer is added or productivity increases. To explain this, the total competition hypothesis predicts that competition above ground and below ground both become more important, leading to more competitive exclusion, whereas the light competition hypothesis predicts that a shift from below‐ground to above‐ground competition has a similar effect. The density hypothesis predicts that more above‐ground competition leads to mortality of small individuals of all species, and thus a random loss of species from plots.2 Fertilizer was added to old field plots to manipulate both below‐ground and above‐ground resources, while shadecloth was used to manipulate above‐ground resources alone in tests of these hypotheses.3 Fertilizer decreased both ramet density and species diversity, and the effect remained significant when density was added as a covariate. Density effects explained only a small part of the drop in diversity with fertilizer.4 Shadecloth and fertilizer reduced light by the same amount, but only fertilizer reduced diversity. Light alone did not control diversity, as the light competition hypothesis would have predicted, but the combination of above‐ground and below‐ground competition caused competitive exclusion, consistent with the total competition hypothesis.
Temporal changes in spatial patterns of soil moisture following disturbance: an experimental approach
Authors: Guo Dali , Mou Pu , Jones Robert H. , Mitchell Robert J. 
Published: March 2003

Summary1 We quantified changes in spatial heterogeneity of soil moisture over 2.5 years in a Pinus elliottii Engelm. forest, following disturbance and succession. We harvested or girdled upper canopy trees and measured three components of heterogeneity – global (non‐spatial) variability, spatial dependence and temporal persistence – in replicate plots, using sample points arrayed at a fine scale (0.5–6 m) nested within a coarser scale (5–60 m).2 Global variability increased after disturbance and then declined, eventually returning to the level recorded in an undisturbed plot. Harvesting resulted in greater, more rapid and more prolonged changes in global variability than girdling.3 Geostatistical parameters for measuring spatial dependence were largely unaffected by disturbance. Spatial dependence was, however, quite variable across replicate plots and was stronger at the finer sampling scale.4 Spearman rank correlations showed that the spatial pattern of soil moisture had greater long‐term persistence in the undisturbed and girdled plots than in the harvested plots.5 Some elements of spatial heterogeneity appear to vary over time in a predictable manner. Detection of temporal trends may be improved if multiple components of heterogeneity are quantified, more than one scale of observation is used, replicate plots are employed and sole reliance on geostatistics is avoided.
Riposte to Guest Commentaries on ‘Problems associated with randomized controlled clinical trials in breast cancer’
Authors: Johnson Ann E. 
Published: March 2003

This paper addresses the objections of Professor M. Baum and Mr W. J. Cunliffe to my thesis that the randomized controlled clinical trial is a poor tool for the investigation of the treatment of breast cancer, argued in a discussion paper entitled ‘Problems associated with randomized controlled clinical trials in breast cancer’ (A.E. Johnson, 1998, Journal of Evaluation in Clinical Practice4, 119–126). The objections range from those that have a philosophical basis, through those founded on differing concepts of the classification of primary tumours and the nature of the metastatic tumour, to those that question the reliability and usefulness of the clinical evaluation of response to treatment in terms of histological grade and rate of tumour shrinkage. An alternative approach to research through primary systemic therapy with selection of treatment according to predicted tumour behaviour was severely criticized, both on the preceding grounds and because it was assumed that the alternative to randomization is management by anecdote.These objections are examined and evidence in support of reliable and useful clinical measurement of response is presented in some detail. The problems associated with randomization as a technique for the evaluation of treatments, when the intrinsic variability of tumours is very large without the intervention of treatment, remain unsolved.
Publishing web‐based guidelines using interactive decision models
Authors: Sanders Gillian D. , Nease Robert F. , Owens Douglas K. 
Published: March 2003

AbstractCommonly used methods for guideline development and dissemination do not enable developers to tailor guidelines systematically to specific patient populations and update guidelines easily. We developed a web‐based system,ALCHEMIST, that uses decision models and automatically creates evidence‐based guidelines that can be disseminated, tailored and updated over the web. Our objective was to demonstrate the use of this system with clinical scenarios that provide challenges for guideline development. We used theALCHEMISTsystem to develop guidelines for three clinical scenarios: (1)Chlamydiascreening for adolescent women, (2) antiarrhythmic therapy for the prevention of sudden cardiac death; and (3) genetic testing for the BRCA breast‐cancer mutation.ALCHEMISTuses information extracted directly from the decision model, combined with the additional information from the author of the decision model, to generate global guidelines.ALCHEMISTgenerated electronic web‐based guidelines for each of the three scenarios. UsingALCHEMIST, we demonstrate that tailoring a guideline for a population at high‐risk forChlamydiachanges the recommended policy for control ofChlamydiafrom contact tracing of reported cases to a population‐based screening programme. We usedALCHEMISTto incorporate new evidence about the effectiveness of implantable cardioverter defibrillators (ICD) and demonstrate that the cost‐effectiveness of use of ICDs improves from $74 400 per quality‐adjusted life year (QALY) gained to $34 500 per QALY gained. Finally, we demonstrate how a clinician could useALCHEMISTto incorporate a woman’s utilities for relevant health states and thereby develop patient‐specific recommendations for BRCA testing; the patient‐specific recommendation improved quality‐adjusted life expectancy by 37 days. TheALCHEMISTsystem enables guideline developers to publish both a guideline and an interactive decision model on the web. This web‐based tool enables guideline developers to tailor guidelines systematically, to update guidelines easily, and to make the underlying evidence and analysis transparent for users.
The potential influence of small group processes on guideline development
Authors: Pagliari Claudia , Grimshaw Jeremy , Eccles Martin 
Published: March 2003

AbstractThe authors discuss the important and often neglected role of psychosocial factors in guideline development. Such factors can influence the process by which guideline development groups interact, make decisions and achieve consensus, which may have important implications for the validity and reliability of the recommendations they produce. Particular attention is paid to the role of social influence within multidisciplinary groups and the importance of good chairmanship. Recommendations for participants, chairmen and guideline development bodies are given.
Medical ethics education: to what ends?
Authors: Gross Michael L. 
Published: March 2003

AbstractThe goals of medical ethics education comprise several dimensions: legal duties to secure informed consent, tell the truth and protect confidentiality; objective competencies that include an understanding of DNR regulations and surrogate decision‐making procedures; discursive moral skills such as moral sensitivity, reciprocity and moral development that combine into the capacity for moral dialogue and debate; and finally, behavioural goals that challenge moral education to nurture a more humane, sensitive and communicative physician. Part one of this paper describes each of these goals, together with some of the inherent difficulties affecting implementation. Part two presents survey data from medical ethics instructors (n= 126) who were asked about the importance of each goal and their ability to successfully achieve each aim. While each goal is highly rated, only those goals associated with legal duties and objective competencies are thought to be achieved with any degree of relative success. Goals associated with character transformation, unique to medical ethics education, are among the most difficult to achieve. Additional empirical data corroborate these impressions. Moreover, it is not clear that medical ethics education has much to do with good care. Empirical data are scarce and the conceptual relationship between ethics and care remains highly problematic. Part three offers a number of divergent interpretations of care and concludes that they have little to do with medical ethics. There is no reason to expect that medical competence should be affected by moral competence. Medical ethics therefore might then be viewed as an educational enhancement: unnecessary for healthy doctoring but desirable among a small percentage of the profession who maintain an interest in ethical problems.
Haemorrhagic kidney syndrome of Atlantic salmon, Salmo salar L.
Authors: Byrne  , MacPhee  , Ostland  , Johnson  , Ferguson  
Published: March 2003

AbstractThis report describes a new syndrome affecting farmed Atlantic salmon on the Canadian east coast that has resulted in increased morbidity and mortality in affected stocks. The major pathological findings are apparent only microscopically and include renal interstitial haemorrhage and acute tubular necrosis and tubular casting. As a result, the disease has become known as haemorrhagic kidney syndrome (HKS). Affected fish are lethargic and anorectic, and lack external lesions. Clinically, HKS fish are anaemic, hypoproteinaemic and hyperosmolalic, with increased serum concentrations of sodium and chloride. At necropsy, internal changes ranged from apparently normal to include one or several of the following: swelling and/or patchy reddening of the kidney, pale gills, exophthalmos, serosanguinous ascites, darkening of the posterior intestine and splenomegaly. Ultrastructurally, viral inclusions were found in the cytoplasm of erythrocytes of HKS fish, and there were unusual electron‐dense inclusions within the tips of renal tubular microvilli of HKS fish. The significance and relevance of the ultrastructural findings to HKS are unknown. Virus isolation was attempted using CHSE, RTG‐2, FH‐10, BB and EPC cell lines; no virus was isolated. Bacteriological analysis failed to reveal significant pathogens. Analysis of tissues for heavy metals and pesticides was negative. Assays for clostridial toxins, lipopolysaccharide and verotoxins were negative. The aetiology of HKS remains unresolved.
Examination of abdominal organs and diagnosis of deficient septum transversum in Atlantic salmon, Salmo salar L., using diagnostic ultrasound imaging
Authors: Poppe  , Midtlyng  , Sande  
Published: March 2003

AbstractThe use of diagnostic ultrasound for non‐invasive diagnosis of hypoplasia or aplasia of septum transversum in farmed Atlantic salmon, Salmo salar L., is described. This investigation shows that this method is fast and accurate (sensitivity = 100%; specificity 97.87%). We therefore recommend the method to be used both experimentally and in the field. As the causes of this malformation are unknown, it is recommended that broodfish with this anomaly should be excluded from the broodfish pool.
Non‐specific immune response of Nile tilapia, Oreochromis nilotica, to the extracellular products of Mycobacterium spp. and to various adjuvants
Authors: Chen  , Yoshida  , Adams  , Thompson  , Richards  
Published: March 2003

AbstractNile tilapia were immunized by injecting extracellular products (ECP) of Mycobacterium spp. (strain TB40, TB267 or the type strain Mycobacterium marinum) into their swim bladders. A variety of adjuvants – Freund's complete adjuvant (FCA), Freund's incomplete adjuvant (FIA) and Titremax – were similarly injected into additional groups of tilapia. Phosphate‐buffered saline (PBS) was used as a control. The number of nitroblue tetrazolium (NBT)‐positive cells observed in the swim bladder of the immunized fish had significantly increased by the fourth day post‐immunization. By day 8, the number of NBT‐positive cells in fish immunized with ECP from mycobacteria strains TB40 or TB267 were fewer than in fish immunized with ECP from M. marinum or fish injected with FCA or FIA. The level of lysozyme activity detected in the serum of fish 4 days after being immunized with ECP from various Mycobacterium spp. was also significantly higher than that found in the serum of the control fish. Head kidney macrophages showed an enhanced reduction of NBT when cultured in vitro with 1 μg ml–1 of ECP. Concentrations greater than this (10 or 100 μg ml–1) were found to suppress the reduction of NBT by the macrophages.
Oral nutritional supplements promote significant weight gain in cystic fibrosis patients
Authors: Skypala  , Ashworth  , Hodson  , Leonard  , Knox  , Hiller  , Wolfe  , Littlewood  , Morton  , Conway  , Patchell  , Weller  , McCarthy  , Redmond  , Dodge  
Published: March 2003

Background: Malnutrition and poor growth are major problems for many patients with cystic fibrosis (CF), and nutritional supplements can enhance the success of dietary strategies. The purpose of this study was to assess Scandishake (Scandipharm Ltd, U.K.), an energy dense (2.0 kcal/ml) oral supplement.
Methods: The study design included a 4‐week monitoring period, followed by 8 weeks of supplementation with Scandishake. The subjects had anthropometry assessed at weeks 0, 4 and 12, and their dietary intake assessed at weeks 0 and 12.Results: Data from 26 patients (16 male, 10 female; age range 9–34 years) showed a significant mean weight increase of 1.9 kg (range 1.6–4 kg) and a mean increase of 0.5 cm (range 1.1–2.7 cm) in mid‐arm muscle circumference. There was also an increase in energy intakes, rising from a mean of 11.15 MJ (2665 kcals) to a mean of 13.42 MJ (3208 kcals) (
P < 0.01), and the mean of individual percentages of estimated average requirement (EAR) for energy increased from 120% (73–182%) to 143% (67–221%).Conclusion: The energy dense formulation of Scandishake makes it a useful adjunct in the treatment of malnutrition and the promotion of normal growth in patients with CF.
The dietary intake of people with non‐insulin‐dependent diabetes (NIDDM): how valid is self‐reported intake?
Authors: Adams  
Published: March 2003

Background: In diabetes care, an accurate assessment of dietary intake is essential for clinical management. This study assessed the validity of dietary records from people with NIDDM by comparing reported energy and protein intakes with estimated total energy expenditure (TEE) and urinary nitrogen excretion.Method: To assess energy and nutrient intake 185 patients kept dietary records for two 3‐day periods. Basal metabolic rate (BMRest) was estimated to calculate reported energy intake/BMRest. Appropriate age and sex‐specific physical activity levels (PAL=TEE/BMR) from published doubly‐labelled water studies of TEE, were used to calculate a cut‐off PAL for energy intake/BMRest, below which intakes were statistically unlikely to be valid. A subgroup (46 patients) collected a complete 24‐h urine sample to compare nitrogen excretion with protein intake.Results: The mean value of energy intake/BMRest (1.14±0.3) was markedly below the calculated cut‐off point (1.58±0.06) suggesting widespread underreporting. Protein intake (82.5±21.3) was also lower than estimated protein losses (92.5±19.4). Obese and female NIDDS were more likely to underreport and their intakes were closer to the diabetes dietary recommendations.
Conclusion: This study found that people with NIDDM were likely to underreport their food intake.
Parenteral nutrition. Do dietitians have a role? Results of the Parenteral and Enteral Nutrition Group survey
Authors: Gilmour  , Glencorse  
Published: March 2003

Aim: To examine the role of the nutrition support dietitian in parenteral nutrition (PN).Methods: Two postal surveys were sent to members of the Parenteral and Enteral Nutrition Group (PENG) in 1993 and 1995. The questionnaires were designed to examine four key areas of dietetic practice in PN.Results: Response rates of 73% in 1993 and 75% in 1995 were achieved. In 1993, a minority of dietitians, only 5%, assumed total responsibility for the formulation of parenteral nutrition regimens. In 1995 this figure had risen to 14%. However, 83% of nutrition support dietitians wanted to increase their involvement in PN. Results from the 1995 survey showed that 42% of dietitians felt that education at undergraduate level was inadequate, whilst 58% felt education at postgraduate level could be improved.Conclusion: Both surveys raised a number of issues concerning present prescribing practices of PN in the UK. There appears to be little practical clinical nutrition education concerning PN either in the medical, dietetic or pharmaceutical curriculum. This may indicate that present prescribing practices are suboptimal. Because dietitians are involved in nutritional assessment and calculation of nutritional requirements it would seem sensible that dietitians should have a greater prescribing role in PN. In order to become competent advisors in this area, more must be done to improve education for dietitians at the undergraduate and postgraduate levels, otherwise the opportunity to be actively involved in this area may be lost.