bluuebunny/crossref_metadata_2025_split huggingface dataset:
Demographic variation and population viability in Gentianella campestris: effects of grassland management and environmental stochasticity
Authors: Lennartsson Tommy , Oostermeijer J. Gerard B. 
Published: March 2003

Summary

Transition matrix models were used to evaluate the effects of environmental stochasticity and four different methods of grassland management on dynamics and viability of a population of the biennial Gentianella campestris (Gentianaceae) in species‐rich grassland. Data were collected between 1990 and 1995.
Continuous summer grazing, the prevailing management strategy in Scandinavian grasslands, resulted in high recruitment of new plants, mainly because litter accumulation was prevented and gaps were created by trampling. Trampling and repeated grazing, however, caused damage which reduced seed production. Lambda for the average matrix was c. 0.77, and a stochastic matrix model yielded an extinction probability for the total population of c. 0.08 within 50 years.
Mowing in mid‐July (used as a conservation tool) increased seed production, but litter accumulation following re‐growth of the vegetation prevented establishment. Lambda and extinction risk were similar to continuous grazing.
Mowing in October (another conservation tool) promoted recruitment because of low litter accumulation, but the seed output decreased because plant growth was impaired by tall vegetation. Lambda was 0.64, while the extinction probability was very high (c. 0.98 within 50 years).
Mid‐July mowing followed by autumn grazing (the historical management regime) yielded high values for both seed production and establishment of rosettes. Lambda was 0.94 and the probability of extinction within 50 years was below detection level.
Log‐linear analysis showed that the matrices differed significantly both between treatments and between years. The latter indicates environmental stochasticity, here caused by summer drought that increased the extinction risk. Lambda may be slightly underestimated because drought occurred in one out of five summers during the study period, which is high compared with the natural frequency.
We conclude that traditional grassland management is more favourable for G. campestris than the methods that prevail in Scandinavia today. This indicates a serious conservation problem, because grazing has replaced traditional management in many of the remaining semi‐natural grasslands throughout Europe.
Patterns of fruit production in the subdioecious plant Astilbe biternata (Saxifragaceae)
Authors: Olson Matthew S. 
Published: March 2003

Summary

Patterns of fruit production in the subdioecious plant Astilbe biternata were used to test whether sex ratio is correlated with relative fruit production by females and males; whether males that produce large inflorescences also produce proportionally more fruit; whether male fruit production is correlated with habitat type; and whether pollen limitation could affect fruiting.
Inflorescence length, a good predictor for flower production, was surveyed along with percentage fruit production and sex ratio in 22 populations from throughout the species range, including eight populations where plants were growing in both roadside and understorey habitats. In one population, the percentage fruit production of males and females was assessed in relation to the distance from to the nearest pollen source.
There was significant variation in sex ratios among populations, but this was not correlated with relative (female:male) total fruit production. Fruiting males produced smaller inflorescences than either females or non‐fruiting males, and within fruiting males, individuals with large inflorescences produced proportionally fewer fruits than those with small inflorescences. The proportion of males that produced fruit was higher in roadside than understorey habitats whereas all females produced fruit in both habitats. Female, but not male, percentage fruit production decreased with distance from the nearest potential pollen source.
Allocation patterns to fruiting differed between males and females. Percentage fruit production declined as inflorescence size increased for both males and females. Astilbe biternata males with a genetic propensity to produce fruit might produce smaller inflorescences, or fruit production might be determined by resource availability within the inflorescence after the inflorescence is produced.
Vernalization requirement of wild beet Beta vulgaris ssp. maritima: among population variation and its adaptive significance
Authors: Boudry Pierre , Mccombie Helen , Van Dijk Henk 
Published: March 2003

Summary

Seven populations of Beta vulgaris ssp. maritima (wild beet) situated along a latitudinal cline were studied for their vernalization requirement and its consequences for fitness.
Various cold regimes were applied in glasshouses and experimental gardens with plants of different ages. Three additional experimental sites (on the French Mediterranean, Atlantic and North Sea coasts) situated near three of the sampled populations, and thus including a reciprocal transplant design, were used to evaluate the influence of latitude under natural conditions. Survival and plant size were measured over 3 years.
The vernalization requirement was greater in plants from more northern origins. The level of cold required to allow flowering overcompensated for the colder springs, so that northern plants in northern sites flowered less than southern plants in southern sites.
Young seedlings were more difficult to vernalize than plants that had already developed vegetative rosettes.
Differences in vernalization requirement seem to be an adaptive response to spring temperatures and season length in a particular latitude. A whole winter vernalization almost always led to flowering in the subsequent year whatever the latitude or geographical origin.
Plants from the Atlantic and Channel coasts showed the highest lifetime reproductive success at all sites. Southern populations were better adapted to disturbed habitats as shown by their higher first‐year reproductive success. The North Sea population had a lower reproductive success than the Atlantic populations, even in its native environment.
Density‐dependent regulation in an invasive seaweed: responses at plant and modular levels
Authors: Arenas Francisco , Viejo Rosa M. , Fernández Consolación 
Published: March 2003

Summary

The effects of density on the vital rates, growth form and population size structure of the invasive seaweed Sargassum muticum (Yendo) Fensholt were evaluated experimentally.
The initial difference in plant number between the highest and the lowest density (200 and 6400 plants m−2) was considerably reduced by the end of the experiment. Surprisingly, this was mostly due to numbers increasing at lower densities, probably because microscopic forms were not removed during the experimental thinning.
The allometric length–dry mass relationship fitted a simple linear model on log‐log scale for both the highest and the lowest densities, but had different slopes. At higher densities plants became taller and thinner as a consequence of variations in the production and growth of modules.
Mean size (dry mass) and the development of size hierarchies of plants were affected by both the addition of further (microscopic) recruits and asymmetrical competition among plants. Plant length distributions were also influenced by changes in the growth form of plants. The length hierarchies of main branches also suggested the presence of asymmetrical competition at this modular level.
Density influenced both mean size and morphology of the plants and thus induced changes in reproduction. The negative effect of density on individual plant size reduced the percentage of fertile plants and possibly their annual reproductive allocation, but these effects may be attenuated by morphological responses.
The responses of S. muticum to crowding are closely linked to its ability to colonize bare space. The massive reproductive output and very limited dispersal range account for local and dense recruitment patterns. Our results suggest that the responses of S. muticum to crowding allow the establishment of dense populations with high persistence and resistance to colonization by other species.
The synchronized and intermittent reproduction of forest trees is mediated by the Moran effect, only in association with pollen coupling
Authors: Satake Akiko , Iwasa Yoh 
Published: March 2003

Summary

Coupled map models for the dynamics of individuals’ energy reserves have shown that large between‐year fluctuation in tree seed crops can occur in a constant environment and that reproduction can be synchronized over the whole forest if fruit production is limited by the availability of outcross pollen.
In this paper we examine the effects of the environmental fluctuation experienced by different individuals. The reactive changes in annual productivity and the reproductive threshold are accounted for by an additional term in the energy reserve dynamics.
If individuals show chaotic seed production, strongly correlated environmental fluctuations (the Moran effect) failed to produce a high positive correlation in seed production across the forest in the absence of pollen limitation. Regardless of the high nonlinearity of resource dynamics, a large correlation was maintained when both pollen limitation and correlated environmental fluctuation occurred.
We derived a regression formula for the degree of synchronization when pollen coupling occurred only on a local scale. The correlation coefficient of seed crops between distantly located individuals decreases with the resource depletion coefficient, but it increases with the strength of pollen limitation, the standard deviation of environmental noise, and the correlation of environmental noise between different trees.
Conflict of interests, vested interests and health research
Authors: Little Miles 
Published: March 2003

AbstractThis paper examines conflict of interest as it may arise in the activities of research advisory committees and ethical review committees. It distinguishes between vested interests and true conflict of interest. It also examines the ways in which stakeholdings differ from vested interests and conflicting interests differ from conflicts of interest. It explores the overlapping terrain of corruption and conflict of interest. The paper further examines the ways in which scientists, communities and the subjects of medical research all have legitimate stakeholdings in medical research. Each group thus has differently vested interests in the outcomes of the research. The vested interests of medical scientists are particularly complex because scientists have moral commitments to the welfare of patients that may compete with professional and personal interests in the outcome of research performed on those patients as research subjects. The more these interests diverge, the more opportunity will arise for conflict of interest. These observations have implications for the constitution of research advisory and ethical review committees, and the ways in which their discussions are conducted. Some practical help with protocols of discussion can be gained from philosophical and management writings.
Measuring improved patient choice
Authors: Holmes‐Rovner Margaret , R. Rovner David 
Published: March 2003

AbstractPatient decision support (PDS) tools or decision aids have been developed as adjuncts to the clinical encounter. Their aim is to support evidence‐based patient choice. Clinical trials of PDS tools have used an array of outcome measures to determine efficacy, including knowledge, satisfaction, health status and consistency between patient choice and values. This paper proposes that the correlation between ‘subjective expected utility’ (SEU) and decision may be the best primary endpoint for trials. SEU is a measure usually used in behavioural decision theory. The paper first describes how decision support tools may use decision analysis to structure the presentation of evidence and guide patient decision‐making. Uses of expected utility (EU) are suggested for evaluating PDS tools when improving population health status is the objective. SEU is the theoretically better measure when internal consistency of patient choices is the objective.
Cost‐effectiveness of ancrod treatment of acute ischaemic stroke: results from the Stroke Treatment with Ancrod Trial (STAT)
Authors: PhD Gregory P. Samsa , MD David B. Matchar , ScD G. Rhys Williams , MD David E. Levy 
Published: March 2003

Abstract Rationale, aims and objectives This paper describes a recent randomized
controlled trial in which 42% of patients receiving ancrod attained a favourable
outcome in comparison with 34% of controls. Although the above effect size
corresponds to a number needed to treat (to achieve a favourable outcome) of approximately
13, intuition does not necessarily suggest what would be the overall impact of a
treatment with this level of efficacy. Methods The objective was to evaluate
the cost‐effectiveness of ancrod. Cost‐effectiveness analysis of data from the Stroke
Treatment with Ancrod Trial (STAT) trial was carried out. The participants were 495
patients with data on functional status at the conclusion of follow‐up. Short‐term
results were based upon utilization and quality of life observed during the trial;
these were merged with expected long‐term results obtained through simulation using
the Stroke Policy Model. The main outcome measure was incremental cost‐effectiveness
ratio. Results Ancrod treatment resulted in both better quality‐adjusted life
expectancy and lower medical costs than placebo as supported by sensitivity analysis.
The cost differential was primarily attributable to the long‐term implications of
ancrod’s role in reducing disability. Conclusions If ancrod is even modestly effective, it will probably be cost‐effective (and, indeed, cost‐saving) as well. The net population‐level impact of even modestly effective stroke treatments can be substantial.
A preliminary study for the development of a scale to assess perceptions about physicians
Authors: MD Tacettin Inandi , MD Nalan Sahin , MD Asuman Guraksin 
Published: March 2003

Abstract Rationale, aims and objectives This study aimed to develop a scale that
can be used to assess the perceptions of the community about physicians and their
medical practice. Methods A Likert‐type scale was developed and applied to
220 subjects twice within a 7–10 day interval. Internal consistency reliability
and test–retest reliability were used as indicators of the reliability of
the scale. Results Chronbach’s alpha values obtained from two reliability
tests were 0.82 and 0.83, respectively, and correlation coefficient between the two
tests was 0.61. The mean value of items indicated that perceptions about physicians
were between ‘negative’ and ‘neutral’. Conclusions The reliability of this scale was found to be at acceptable levels and therefore it can be used to assess the perceptions of people from different social classes about physicians.
The effectiveness of cognitive‐behavioural interventions provided at Outlook: a disfigurement support unit
Authors: Kleve Liv , Rumsey Nichola , Wyn‐Williams Menna , White Paul 
Published: March 2003

AbstractRationale, aims and objectives The establishment and evaluation of a disfigurement support unit (Outlook), based in a district general hospital is described.Methods The effectiveness of cognitive‐behavioural interventions provided for 36 adults referred from a range of specialties was evaluated through the use of semistructured interviews, and standardized and visual analogue scales completed at initial assessment, at the end of intervention and at 6 months follow‐up.Results There were significant improvements on all measures at the end of intervention, which were maintained at 6‐month follow‐up, including social anxiety, appearance‐related distress, general anxiety and depression. Clients also reported significant improvements in positive affect and satisfaction with life. They felt more confident with strangers and in dealing with new social situations. In addition, their perceptions of the noticeability of their condition, both to themselves and to others, had significantly reduced. Dendograms revealed two distinct groupings of clients, with one group showing greater improvements following intervention.Conclusions The results suggest that Outlook represents a valuable addition to the current provision of surgical and medical care.
Democratic deficit and communication hyper‐inflation in health care systems
Authors: PhD Peter Andras , MD Bruce G Charlton 
Published: March 2003

AbstractThere is a widespread perception of poor performance and reduced trust in relation to health care systems. The roots of this problem are interpreted in terms of the democratic deficit and communication hyper‐inflation. The democratic deficit is characterized as a persistent but chronically unsatisfied demand for complete public authority over all significant societal institutions – including the health care system. However, such professional institution systems necessarily perform their functions using specialized internal languages, which are not transparent to external scrutiny. Furthermore, professional institution systems tend to eliminate all subjective and imprecise criteria, such as individual moral values. This situation encourages communication inflation, which describes the large and unpredictable divergence between the real and nominal informational content of communications. Hyper‐inflation is generated by the development of morality‐free information management subsystems (specifically public relations and advertising) to the extent that ‘official’ communications convey almost zero reliable information. Reduction of the democratic deficit and control of communication inflation depends upon successful penetration of the health care system by representative public values, including individual morality.
What criteria do patients use when judging the effectiveness of psoriasis management?
Authors: Ersser Steven J. , Surridge Heidi , Wiles Anne 
Published: March 2003

AbstractJudgements on the effectiveness of psoriasis management are based on clinical criteria employed by dermatologists, and how they take account of patients’ experiences in the process of history taking. In this study the aim was to gain the in‐depth patients’ perspective and investigate the criteria that they employ when making judgements about the effectiveness of their therapy. These findings were then compared with the clinical and research literature on the clinical effectiveness of psoriasis treatments. The study design is exploratory‐descriptive, using a qualitative ethnographic approach. In‐depth interviews were undertaken in an outpatient department dermatology clinic. A purposive sample of 20 adult patients currently attending represented the following types of psoriasis: guttate, chronic plaque and scalp. A key comparable finding between the literature and the interview data is that dermatologists emphasize observable criteria of effectiveness, such as clearance of the lesion, whereas patients emphasis focuses on the subjective concerns, such as suppleness, softness and alleviation of itch. This discrepancy needs to be considered during history taking, in relation to its impact on therapy concordance and in the use and development of outcome measures used for clinical assessment and evaluations of psoriasis therapy.
The influence of Gyrodactylus salaris Malmberg 1957 (Monogenea) on the epidermis of Atlantic salmon, Salmo salar L., and brook trout, Salvelinus fontinalis (Mitchill): experimental studies
Authors: Sterud  , Harris  , Bakke  
Published: March 2003

AbstractThe effect of Gyrodactylus salaris on the epidermal structure of hatchery‐reared brook trout parr and Norwegian Atlantic salmon parr was evaluated. Both species were initially susceptible to this parasite, but whereas populations on salmon increased until the host died, brook trout responded to, and eventually eliminated, their infections. Salmon skin samples taken 14 days p.i. showed a reduced mucous cell concentration (less than 1500 cells mm–2 on the head compared with 2000 cells mm–2 in controls; the same trend was also seen in other sites) and the epidermis was thinner (48 μm compared with 60 μm on pectoral fins; similar trend seen in other sites) than in uninfected controls kept under identical conditions. Brook trout skin samples were taken 50 days p.i., when the hosts had responded to, and almost eliminated, their infections. No change was then observed in mucous cell density, while the number of epidermal cell layers and the epidermal thickness of brook trout had increased slightly following infection. These results are related to the nature of the host response, and the thinning of the epidermis and loss of mucous cells may in some way be related to the inability of Norwegian salmon parr to respond to the parasite.
The phylogeny of Anguillicola crassus and A. globiceps based on partial 18S ribosomal RNA sequences
Authors: Hirose  , Yabu  , Hirono  , Aoki  
Published: March 2003

AbstractThe parasitic nematodes Anguillicola crassus and A. globiceps infect the swimbladder of eels. To investigate the relationship of these species at the molecular level, the small subunit ribosomal RNA (18S rRNA) genes of A. crassus and A. globiceps were cloned and their nucleotide sequences determined. The 18S rRNA gene of A. crassus and A. globiceps were found to have similar lengths (886 and 888 base pairs, respectively) and demonstrated extensive similarity in their nucleotide sequences, showing 98.8% homology. However, the sequence homology of the 18S rRNA gene of A. crassus with that of other nematodes was found to be in the range of 72.7–89.0% homology, whilst that of A. globiceps was in the range of 73.1–89.4% homology. A phylogenetic reconstruction showed A. crassus to be closely related to A. globiceps. The analysis of nucleotide sequences of the 18S rRNA gene of fish parasites has proven useful in supporting species status and phylogenetic relationships.
Pseudomonas fluorescens, infectious pancreatic necrosis virus and environmental stress as potential factors in the development of vaccine related adhesions in Atlantic salmon, Salmo salar L.
Authors: Colquhoun D. J. , Skjerve E. , Poppe T. T. 
Published: March 2003

AbstractThe possible influences of contaminant bacteria, Pseudomonas fluorescens, infectious pancreatic necrosis virus (IPNV) and environmental stress on the development of vaccine‐related peritoneal adhesions in Atlantic salmon, Salmo salar L., pre‐smolts were investigated. Groups of 50 fish (≈ 30 g) vaccinated with a commercial, triple valent, metabolizable oil‐adjuvanted vaccine were pre‐injected with IPNV, co‐injected with Pseudomonas fluorescens or subjected to routine stress both solely and in combination. Fish from each group were sampled monthly over 3 months. Vaccine side‐effects were scored macroscopically and examined histologically. Fibrous adhesions were apparent in all groups from the first sampling date. Treatments including co‐injection of P. fluorescens and additional environmental stress were found to confer significantly higher degrees of adhesion than vaccine alone. The findings are discussed in relation to vaccination procedures. Persistent or covert IPNV infection could not be confirmed in subsequent samplings.