bluuebunny/crossref_metadata_2025 huggingface dataset:
Foliage area and crown nitrogen turnover in temperate rain forest juvenile trees of differing shade tolerance
Authors: Lusk Christopher H. , Contreras Olga
Published: March 2003

1 Shade‐tolerant angiosperm trees are reported to require relatively fertile soils in temperate forests. We explored the possibility that high foliage allocation in shade‐tolerant species could result in higher whole‐plant nitrogen demands than in light‐demanding trees of comparable diameters. We measured foliage mass and area, leaf life span, and nitrogen (N) content of fresh foliage and leaf litter for juveniles of 11 evergreen angiosperms in a Chilean temperate rain forest. This permitted estimation of annual nitrogen losses in leaf litter fall by individuals of a given diameter.

2 Leaf life spans were longest in shade‐tolerant species. The highest leaf N levels were found in small short‐lived early successional trees, whereas among longer‐lived species there was no general relationship of leaf N with shade tolerance level. Shade‐tolerant species had lower N resorption efficiencies, and therefore higher leaf litter N concentrations on an area basis, than light‐demanding associates.

3 Foliage mass, foliage area and total crown N pool were strongly positively related to shade tolerance level.

4 Interspecific variation in annual N losses in leaf litter fall was more closely related to foliage area (R2 = 0.52) than to N concentration of leaf litter (R2 = 0.31) or leaf lifetimes (R2 = 0.01). Although the short‐lived early successional species Embothrium coccineum had the highest annual crown N losses of the 11 species, shade‐tolerant species had higher annual losses than light‐demanding overstorey dominants of comparable longevities.

5 The results are consistent with the proposal that the costs of obtaining enough N for crown maintenance and expansion may constrain the fitness of shade‐tolerant angiosperm trees in late successional stages on infertile sites, when soil nutrient availability is reduced by increased uptake and sequestration in biomass and litter. On the other hand, high N loss rates may be more sustainable for short‐lived early colonists that complete their life cycles in the initial stages of secondary succession, when nutrient availabilities are often relatively high.
Infection of Trientalis europaea by the systemic smut fungus Urocystis trientalis: disease incidence, transmission and effects on performance of host ramets
Authors: Piqueras Jesús
Published: March 2003

1 The effects of fungus infection on a natural population of the pseudoannual plant Trientalis europaea were followed for 4 years.

2 The incidence of the disease was low, showed little temporal variation during the period of study and was not affected by ramet size. Disease reduced flowering, fruiting, stolon length and the number and size of daughter tubers, all of which were positively correlated with ramet size. The year–disease interaction was not significant, except for flowering, suggesting little variation in the aggressiveness of the pathogen.

3 Disease reduced survival of ramets to the end of the growing season, although the effect varied with ramet size, and decreased tuber survival both by reduction of tuber size and by reduction of the overwintering ability of tubers of a given size.

4 For two of the three annual transitions the size of the offspring ramets was affected negatively by infection in the previous year.

5 Disease transmission occurred along the stolons of only 31% of the diseased ramets. The probability of disease being shown in the following year decreased with stolon length.

6 Although disease had a detrimental effect on ramet fitness, the low level of incidence and the stability of the clone dynamics in simulation models suggest only a minor role of the disease in population regulation in this species.
Seed bank formation during early secondary succession in a temperate deciduous forest
Authors: Hyatt Laura A. , Casper Brenda B.
Published: March 2003

1 Seed banks are dynamic entities, with input occurring through dispersal and loss occurring through germination and various sources of mortality. Measures of abundance of seeds in the soil at one point in time cannot distinguish those seeds destined to germinate or die in the next growing season from those entering the long‐term seed bank, and cannot therefore reveal the proportion of seeds that are carried over from year to year.

2 We studied seed bank dynamics in a 2.5‐ha deciduous forest gap by following the fate of a single year’s cohort of seeds over 2 years. Seed input for 1 year, subsequent in situ germination and survivorship were measured at 60 locations. We examined how temporal changes in seed bank composition were affected by the presence of the dominant gap colonizing species Rubus allegheniensis.

3 Over the course of 2 years, both mean seed density and its variance declined. The temporal changes in density were not, however, accompanied by detectable changes in diversity.

4 Three species (R. allegheniensis, Phytolacca americana and Paulownia tomentosa) dominated the seed bank. Seed bank accumulation patterns in Rubus and Phytolacca showed contrasting responses to the presence of Rubus, with Phytolacca excluded from seed banks in such patches through reduced input and increased mortality.

5 First year germination and post‐dispersal mortality interact with seed input to influence the spatial distribution of density and diversity in the long‐term seed bank. Substantial long‐term seed banks do form within temperate forest gaps and patterns of above‐ground vegetation can have substantial effects on their dynamics.
Root hemiparasites and plant diversity in experimental grassland communities
Authors: Joshi Jasmin , Matthies Diethart , Schmid Bernhard
Published: March 2003

1
 We studied the relationship between the diversity of grassland communities and the effects of the generalist hemiparasitic plant Rhinanthus alectorolophus. We compared resistance against biomass loss as a consequence of infection, performance of the parasite and resistance of the parasitized communities to invasion by other plant species. Seeds of the parasite were sown into experimental plots containing 1, 2, 4, 8 or 32 plant species belonging to one or more of three functional groups (grasses, legumes and non‐leguminous herbs).

2  We predicted that infection will reduce host biomass, total community biomass and resistance to invasion, particularly in host communities with low diversity, but that the performance of the parasite will be at its lower level in such communities.

3  The presence of the parasite caused an overall reduction in host biomass per plot, which was mainly due to a strong reduction in the biomass of grasses. As predicted, the effect was smaller in communities with greater functional diversity. However, total community biomass (including the parasite biomass) was increased by more than a third in infected communities of one or two host species, while the parasite had no effect on total biomass of species‐rich communities.

4
 Germination of the parasite was hardly influenced by the diversity of its host community, but early survival decreased with increasing number of functional groups and was lower in plots with legumes than without. However, our hypothesis that the performance of the surviving parasites would benefit from a high functional diversity of hosts was supported. Parasite biomass per individual and per m2 increased with the number of functional groups in the host community, as did reproductive potential.

5  Death of the parasite led to a higher proportion of bare ground in communities when the previously infected communities had low functional diversity, thus enabling subsequent colonization by weeds.
Origin and temporal development of macro‐scale vegetation patterns in the cultural landscape of Denmark
Authors: Odgaard Bent Vad , Rasmussen Peter
Published: March 2003

1 Since the introduction of agriculture, 4000 bc, the Danish region has witnessed a change from almost complete woodland cover to the landscapes present at ad 1800 that were dominated by heathland, cultivated areas, grassland or patchy woodland. We used a combination of pollen records and landscape data to identify the timing and major pathways of this land‐cover transformation.

2 Pollen assemblages dated to about ad 1800 were collected from 20 Danish lakes with a median size of 26 ha. Fossil pollen records for the interval 4500 bc − ad 1800 were compiled from 11 of these 20 sites and divided into 11 time units corresponding to major archaeological periods.

3 Land cover around the 20 sites was digitized from historical maps, dating from the same period as the pollen assemblages. Percentage cover of woodland, heathland, wetland and agricultural land within 2‐ and 5‐km radii were calculated (calculations were also made within 10‐ and 20‐km radii for woodland). Environmental data within 5 km of each site were collected from soil, geological and topographical maps.

4 The ad 1800 pollen assemblages formed three clusters characterized by either a dominance (> 20%) of Calluna (group A), a dominance (> 10%) of Fagus (group B) and a dominance of Poaceae with Fagus < 10% and Calluna < 20% (group C). Respectively, these clusters correspond well to sites where heathland is the dominant land cover, where it has a strong woodland element and where agricultural land is dominant with little, if any, woodland or heathland.

5 Direct and indirect ordinations suggest that the main variation in the pollen assemblages from the 20 sites is related to gradients in soil clay content and in the degree of landscape openness. Land‐cover data from within a 2‐km radius account for almost as much of the variation in pollen data as do land‐cover data from within a 5‐km radius.

6 Indirect ordinations of ad 1800 samples with the fossil records as passive samples reveal that long‐term records from cluster B sites (the ‘1800 woodland type’) show little landscape variation through time. Samples from cluster C sites (the ‘1800 agricultural area type’) show the same starting point as cluster B but their development diverge to more open landscapes. Cluster A sites (the ‘1800 heathland type’) either develop directly from rather wooded landscapes to heathland or by heathland expansion after initial development towards landscapes producing cluster C type pollen assemblages.

7 Chord distances between the ad 1800 sample and the (pre)historic samples at 10 long‐term sites strongly suggest that the between‐site variation in land‐cover characteristic of the early 19th century was already in existence by 1000 bc. Direct ordination of the fossil samples using woodland cover at ad 1800 as an environmental variable and soil clay content as a covariable also indicates that the macro‐scale land‐cover patterns of the historical cultural landscape in Denmark has been present for more than 3000 years.
The role of Equisetum in nutrient cycling in an Alaskan shrub wetland
Authors: Marsh Anne S. , Arnone John A. , Bormann Bernard T. , Gordon John C.
Published: March 2003

1 Although plants of Equisetum spp. are generally thought to be of little value to ecosystems, a study of a cold‐temperate Alaskan shrub wetland showed that they acquired and cycled phosphorus and other nutrients more efficiently than other plant community members. While Equisetum plants represented only 5% of the above‐ and below‐ground biomass in the community, they contained 16% of the P and 24% of the K.

2 Equisetum plants accounted for 29% of the P and 39% of the K in annual community foliage litterfall. Over a 2‐year period, losses from Equisetum litter contributed 55, 41, and 75% of the P, K and Ca litter inputs into soil nutrient pools.

3 The ability of different species of Equisetum to acquire nutrients is linked to their deep rooting habit. While the majority of their roots and rhizomes, and particularly the fine roots, were located in the C horizon, the majority of roots and rhizomes of other species were located in the overlying O horizon. The biomass of Equisetum plants was also correlated with edaphic characteristics of the C horizon.

4 The absorption of nutrients from the C horizon by Equisetum helped bring P and other minerals to the soil surface, increasing the amount of minerals in the O horizon and thus making them potentially available to other species, including Myrica gale, Salix spp., and Carex spp. Productivity in this community is limited by P and N, and the ability of Equisetum to act as a nutrient pump may help explain why its net primary productivity is high for a cold‐temperate wetland.
Morphological plastic responses to water depth and wave exposure in an aquatic plant (Myriophyllum spicatum)
Authors: Strand John A. , Weisner Stefan E. B.
Published: March 2003

We investigated morphological responses of the submerged macrophyte Myriophyllum spicatum L. to water depth and wave exposure when grown in the same substrate at two sites in two eutrophic lakes. Periphyton production was 4–8 times higher at sheltered than at wave‐exposed sites and its influence was further investigated in a glasshouse experiment. Morphological responses in both experiments were compared by allometric analyses, with shoot weight as covariate.

In the field study, plants shoots exhibited similar responses (increased plant height and branch length, and decreased branch number) to sheltered conditions as to deep water. The partitioning between above‐ and below‐ground biomass however, differed, with below‐ground decreasing with an increasing water depth, but increasing or remaining unaffected at sheltered compared with exposed conditions.

In the glasshouse experiment, plant responses to water depth were similar to those in the field study. Furthermore, plant height increased when plants were overgrown with periphyton.

 High production of periphytic algae at sheltered sites appears to cause light limitation of macrophytes. However, other factors such as nutrient uptake also appears to determine morphological responses. At sheltered sites, where leaf nutrient uptake is reduced by abundant periphyton and thick boundary layers, plants allocate more biomass to roots. At deep and wave‐exposed sites, the absence of periphyton allows plants to take up nutrients through their leaves and allocation of biomass to shoots increases photosynthesis.

 Overall, relative allocation to shoot and root biomass appears to be primarily controlled by nutrient availability, whereas allocation of available shoot biomass to particular structures is controlled by light availability.
The relationship of total and per‐gram rankings in competitive effect to the natural abundance of herbaceous perennials
Authors: Howard Timothy G.
Published: March 2003

Using a field experiment and a garden experiment, I estimated the rankings in total and per‐gram competitive effect of non‐woody perennial old‐field species.

 Total competitive effects were defined as the relative reduction in growth of a target from no‐neighbour to with‐neighbour conditions. Per‐gram competitive effects were defined as the per‐unit relative reduction in target growth among increasing neighbour densities, and were determined from the shape of a nonlinear curve fit through a distribution of normalized target performance against neighbour mass.

 In both experiments, mean total competitive effect differed significantly among species, indicating a strong competitive hierarchy. In the garden experiment only species at opposite ends of the ranking differed significantly in per‐gram competitive effect, resulting in a weaker competitive hierarchy based on this measure.

 Nonetheless, rankings of per‐gram competitive effect were more strongly correlated with rank in abundance than were rankings of total competitive effect.

 Per‐gram competitive effect may be more predictive of natural abundance than total competitive effect for at least two reasons. The effects of neighbour abundance on targets are nonlinear, and unlike total effects, per‐gram estimates of competitive effect may therefore indicate how competition changes over time with changing neighbour densities. Also, if higher per‐gram competitive effect reflects higher per‐unit nutrient uptake rates, it would probably be advantageous to a species throughout the individual’s life span, rather than only when the individual is larger than its surrounding neighbours.
Rodent‐limited establishment of bush lupine: field experiments on the cumulative effect of granivory
Authors: Maron John L. , Simms Ellen L.
Published: March 2003

Plants often suffer substantial loss of seeds to consumers. However, because the seed‐to‐seedling transition is frequently ignored, quantitative estimates of the effects of seed consumers on plant population dynamics are rare.

 We examined how post‐dispersal seed predation by rodents affected seedling emergence and subsequent adult plant abundance of bush lupine (Lupinus arboreus), a large N‐fixing shrub common to coastal dunes in California. We monitored patterns of seedling emergence and survival over 3 years for seeds sown into exclosed and control plots.

 We sowed additional cohorts of seeds in the second and third years and compared interannual variation in emergence patterns.

 Rodent exclusion substantially reduced seedling emergence, with an average of 109 seedlings emerging over 3 years from 476 seeds sown in rodent exclusion plots vs. 26 from control plots. The intensity of granivory, however, varied between years, with rodent exclusion increasing emergence from seeds sown in year one, but not in year two.

Winter seedling mortality, due to cutworm herbivory, was similarly high in rodent‐free and control plots, and its net impact was to reduce the difference in seedling abundance. Thus, by mid‐summer in each of the three years, there were only marginally more seedlings in rodent‐excluded vs. control plots.

 The cumulative effect of protecting seeds, was, however, large. After 3 years, an average of four adult lupines were established in rodent‐free plots, whereas only 0.5 were found in control plots and lupine biomass was more than 5‐fold higher in exclusion plots.

 Taken together, the results indicate that rodents play a critical role by limiting the abundance and biomass of a large N‐fixing shrub in dunes.
Hiding from swans: optimal burial depth of sago pondweed tubers foraged by Bewick’s swans
Authors: Santamaría L. , Rodríguez‐gironés M. A.
Published: March 2003

1 We used a combination of laboratory and field experiments to test the hypothesis that the burial depth of Potamogeton pectinatus tubers will vary with local sediment type and swan predation pressure.

2 In the field, mortality due to predation by swans decreased linearly with burial depth (from 100% at the surface to 55% at 225 mm depth) and with sediment clay content. Average tuber size showed an eightfold increase when burial depth increased from 25 to 275 mm.

3 A laboratory experiment showed that plant emergence in spring decreased with increasing planting depth and with decreasing tuber size.

4 An optimization model combining these empirical results showed that optimal tuber survival is achieved if tuber size and burial depth increases as swan predation pressure rises. The model predicted different optimal combinations of tuber size and burial depth for sandy and clay‐rich sediments.

5 A common‐garden experiment showed that plants grown from large tubers produce larger tubers. Significant clonal variation in tuber size was also detected: after standardizing for tuber production, plants originating from sandy sites produced larger tubers than those originating from clay‐rich sites.

6 Our results suggest the existence of spatial refuges for pondweed tubers against swan predation.
Spatial patterns of seed dispersal and seedling recruitment in Corema album (Empetraceae): the importance of unspecialized dispersers for regeneration
Authors: Calviño‐Cancela María
Published: March 2003

Spatial patterns of seed dispersal and seedling recruitment of Corema album were examined among and within habitats to determine the quantitative importance of different dispersers in each type of habitat, and their effectiveness in carrying seeds to suitable habitats for seedling recruitment.

Gulls, blackbirds and rabbits were, respectively, the main dispersers (45%, 40% and 15% of Corema album seeds). Within habitats, blackbirds disperse seeds mainly to female Corema album shrubs, while gulls and rabbits disperse seeds mainly to open ground.

The quantitative role of dispersers varies among habitats because of their habitat preferences, causing the spatial pattern of seed rain to differ.

Open ground has the highest density of seedlings and the highest seedling‐to‐seed ratios. Regeneration is more active in the pioneer scrub than in the mature scrub and the herbaceous vegetation.

Gulls, rather than specialist frugivores, are the most effective dispersers in carrying seeds to suitable sites for recruitment.
Hydrochemical regime of fen and bog in north Japanese mires as an influence on habitat and above‐ground biomass of Carex species
Authors: Nakamura Takatoshi , Uemura Shigeru , Yabe Kazuo
Published: March 2003

The gradient relations proposed by Wheeler & Proctor for NW European mires were tested for six Carex species common in north Japanese mires. Hydrochemical properties of their preferred habitats were compared with above‐ground biomass data.

Canonical discriminant analysis showed that soil water pH was the strongest discriminant between habitats of the Carex species, with total dissolved nitrogen (TDN) concentration also contributing, independently of pH.

Two major patterns were apparent in the distribution of Carex species: pH determines a bimodal distribution into fens with pH > 5.0 and bogs with pH < 5.5, whilst TDN captures the variation in above‐ground biomass within both fen and bog, but does not differ significantly between them.

Concentrations of Ca and Mg were low throughout the pH range. The floristic gradients associated with base richness seen in Euramerican mires do not therefore apply in north Japanese mires, where periodic flooding with neutral water removes the acid fractions in fens, and is the major determinant of pH.

Thus, pH is the best variable for distinguishing between fen and bog, as the poor fen‐rich fen classification is inappropriate for non‐calcareous north Japanese mires.
The interacting effects of genetic variation, habitat quality and population size on performance ofSuccisa pratensis
Authors: Vergeer Philippine , Rengelink Ramses , Copal Annemieke , Ouborg N. Joop
Published: March 2003

We studied the performance of 17 Dutch populations of the perennialSuccisa pratensis, in relation to population size, genetic variation and habitat quality. We used a path‐analytical model to analyse the possible relationships between these variables and performance.

Plants in smaller populations produced fewer seeds per flower head. Their seeds had lower germination rates and higher seedling mortality, and more seeds were dormant or non‐viable.

Population size was also correlated with genetic measures. Small populations had higher inbreeding coefficients than large populations and observed heterozygosity was positively correlated with population size. The mean genetic diversity (expected heterozygosity) was relatively high (Hexp = 0.42), but not correlated with population size.

Less eutrophic habitats appeared to support larger populations. High concentrations of NH4and NO3in the soil were significantly negatively correlated with population size.

Path‐analysis showed thatSuccisa pratensisis vulnerable to habitat deterioration (eutrophication). Population size was strongly influenced by habitat quality. Reduced performance, however, was better explained by direct genetic effects and by habitat deterioration rather than by effects of population sizeper se. Both habitat quality and genetic effects are thus important for population persistence, even in the short term. The results suggest that there will be a continuing decline of the small populations, due to deteriorating habitat conditions, decreased genetic variation and a reduced reproductive capacity.
Environmental sex determination in response to light and biased sex ratios in Equisetum gametophytes
Authors: Guillon Jean‐Michel , Fievet Daniel
Published: March 2003

Sexual differentiation of Equisetum (horsetails) gametophytes is influenced by environmental conditions, and wild populations tend to be female biased. We show that photon irradiance has a very significant and reproducible effect on sex determination in three species of Equisetum grown in vitro.

Under our experimental conditions, high light levels (PAR = 24–48 µmol m−2 s−1) induce most gametophytes to differentiate as female, whereas only males are observed at PAR < 6 µmol m−2 s−1. Addition of sugar to the culture medium, however, promotes male development, suggesting that the effect of increasing photon irradiance is not related to the accumulation of photosynthates.

According to evolutionary theory, environmental sex determination can cause population sex ratios to deviate from unity, and is favoured when the environment consists of patches that differentially affect fitness as a male or a female. However, in two out of three species, we found that the fitness of males increases faster than the fitness of females with increasing light levels, contrary to the predictions of the Charnov and Bull model.

We conclude that environmental sex determination in response to light cannot alone account for the female bias in natural populations of Equisetum gametophytes.
Tailor‐made quality systems in healthcare
Authors: Bij J. D. van der , Broekhuis H.
Published: March 2003

Summary

At present many healthcare organizations are being pressed by national governments or client groups to develop and implement quality systems. Unfortunately, not much is known about the development and implementation of these systems in healthcare organizations. There still are definition questions to be answered and it is not clear in which way a quality system can be outlined and which outline is most effective in a particular situation. In practice, many healthcare organizations adopt ideas from industrial quality management and develop ISO 9000 based quality systems, which are only useful in relatively stable situations. In this paper a typology of healthcare processes is developed on the basis of input and throughput characteristics, following the literature on professional quality systems and service systems. The typology is tested and illustrated by a few case studies. From this typology, on the basis of logic, suggestions have been deduced for tailor‐made quality systems in a general hospital setting. The main point of these systems is an examination, treatment and nursing plan with a timescale. Control is executed on the basis of performance indicators for groups of patients.
Cross‐border health care in the European Union: recent legal implications of ‘Decker and Kohll’
Authors: Hermans Herbert E. G. M.
Published: March 2003

In the European Union a growing number of citizens are receiving medical treatment in a country other than the one in which they are resident. This concerns migrant (frontier) workers, emergency treatment and preauthorized care. Since 1998 a ‘new category’ can be discerned of persons going abroad without prior authorization on the basis of the Decker and Kohll rulings of the EC Court of Justice. Local payers would, because of the Decker and Kohll judgements, be obliged to reimburse patients who travel abroad to circumvent the existing problems with the authorization rules.

During the past years studies within specific so‐called Euregions have been performed to analyse cross‐border flows and provide some more insight in the practical and health policy consequences of the Decker and Kohll judgements. The abolishment of current preauthorization is pleaded for by many respondents in these studies. Waiting lists form an important motive (in particular in the Netherlands) to consume health care in another Member State (Belgium and Germany). The familiarity with (health care in) Belgium eases the unofficial Decker and Kohll route. However, when some parts of the health care services seem to be more expensive in the other Member State, the patient has to pay the difference. New court cases are pending before the European Court of Justice. These cases raise new issues such as the tenability of ‘benefits‐in‐kind’ systems. So far, the Decker and Kohll rulings could be seen as an incentive to enhance access to cross‐border health care in border areas.
Biochemical and molecular typing of Streptococcus iniae isolated from fish and human cases
Authors: Dodson S. V. , Maurer J. J. , Shotts E. B.
Published: March 2003

Streptococcus iniae is an important bacterial pathogen of fish, causing up to 50% mortality in stocks, which has recently been associated with human infections. To determine whether S. iniae isolates from humans and fish are similar, the present authors examined the biochemical profiles and genetic relatedness of these isolates by random amplified polymorphic DNA (RAPD) analysis and repetitive primer polymerase chain reaction(REP PCR). The biochemical profiles differentiated between the human and fish isolates of S. iniae using pyrrolidonyl arylamidase, arginine dehydrogenase, ribose, β‐glucoronidase and glycogen as markers. These biochemical results suggest that the fish and human S. iniae isolates are genetically different. However, RAPD and REP PCR do not have the discriminatory power to differentiate between these streptococcus isolates using five different RAPD primers and BoxA primer.
Bacterial and parasitic pathogens in cultured common dentex, Dentex dentex L.
Authors: Company R , Sitj A ,   ‐Bobadilla, Pujalte M J , Garay E , Alvarez‐Pellitero P ,   and, P J ,   rez‐S,   nchez
Published: March 2003

A bacteriological and parasitological study on cultured common dentex, Dentex dentex L., was conducted in a 2‐year survey. Two different groups of fish were studied: (1) sampled only when mortalities occurred; and (2) sampled periodi‐cally from 10days post‐hatch until the juvenile stage. In both groups, peaks of mortalities coincided with high water temperatures. The same parasites were detected in both groups, except Ichthyophonus sp., which was identified only in the trunk kidney of fish from group 1. Two myxosporeans, Ceratomyxa sp. and Lepthotheca sp., were found in the bile and the trunk kidney, respectively. Epitheliocystis infection was also very frequent in the gills. An unidentified microsporidium, which was found in the liver, occurred very infrequently. Vibrio harveyi was dominant in samples from diseased animals (79%) and clearly associated with mortalities. It was not detected in water or larval homogenates. A high percentage (60%) of the isolates of this species were sorbitol positive. Other less frequently occurring bacteria were V. alginolyticus and Photobacterium (V.) damselae. The disease conditions found in common dentex were considered to be multifactorial in origin.
Characterisation of Aeromonas strains and species by pulsed field gel electrophoresis and principal components analysis
Authors: Livesley M. A. , Smith S. N. , Armstrong R. A. , Barker G. A.
Published: March 2003

Aeromonas genomes were investigated by restriction digesting chromosomal DNA with the endonuclease XbaI, separation of restriction fragments by pulsed field gel electrophoresis (PFGE) and principal components analysis (PCA) of resulting separation patterns. A. salmonicida salmonicida were unique amongst the isolates investigated. Separation profiles of these isolates were similar and all characterised by a distinct absence of bands in the 250kb region. Principal components analysis represented these strains as a clearly defined homogeneous group separated by insignificant Euclidian distances. However, A. salmonicida achromogenes isolates in common with those of A. hydrophila and A. sobria were shown by principal components analysis to be more heterogeneous in nature. Fragments from these isolates were more uniform in size distribution but as demonstrated by the Euclidian distances attained through PCA potentially characteristic of each strain. Furthermore passaging of Aeromonas isolates through an appropriate host did not greatly modify fragment separation profiles, indicative of the genomic stability of test aeromonads and the potential of restriction digesting/PFGE/PCA in Aeromonas typing.
Immunohistochemical and PCR studies of wild fish for Tetracapsula bryosalmonae (PKX), the causative organism of proliferative kidney disease
Authors: Morris D J , Adams A , Feist S W , McGeorge J , Richards R H
Published: March 2003

Tetracapsula bryosalmonae, previously referred to as PKX, causes proliferative kidney disease (PKD) in salmonids and is an economically important myxozoan pathogen in salmonid culture. A variety of molecular and immunological tools have been developed to detect the parasite. To determine the specificity of four monoclonal antibodies (MAbs) raised against T. bryosalmonae, archive material of fish infected with various myxosporean species was obtained and immunostained. Wild fish were also collected from enzootic waters and examined for T. bryosalmonae infection using immunohistochemistry and the polymerase chain reaction (PCR). Three of the MAb probes appear to be specific for T. bryosalmonae while only two of the five sets of primers tested appeared to specifically amplify T. bryosalmonae DNA. The results of the immunostaining and the PCR demonstrate that T. bryosalmonae occurs in the tubules of grayling Thymallus thymallus L., brown trout, Salmo trutta L. and Atlantic salmon, Salmo salar L. outside of the PKD season (June‐September) in the UK. This confirms the results of previous studies that these species are the preferred fish hosts for the parasite in the UK.
Quantitative analysis of an experimental white spot syndrome virus (WSSV) infection in Penaeus monodon Fabricius using competitive polymerase chain reaction
Authors: Tan L T , Soon S , Lee K L , Shariff M , Hassan M D , Omar A R
Published: March 2003

White spot syndrome virus (WSSV) has been a major pathogen of cultured Penaeus monodon Fabricius in Malaysia since 1994. As quantitative study on the replication of WSSV is in its infancy, competitive polymerase chain reaction (PCR) was used for quantitative study of an experimental WSSV infection per os in growout P. monodon. Gills, abdominal integument and abdominal muscle were selected for viral quantification. Infection was detectable as early as 14 h postinfection (h p.i.) in both gills and integument, but the infection in muscle was only detected at 24 h p.i. Gill tissue had the highest viral load, followed by integument and muscle. Typical viral growth curves were obtained for all organs with distinct phases of eclipse (0–24 h p.i.), logarithmic (24–48 h p.i.) and the plateau (48–120 h p.i.). Cumulative mortality rapidly increased from 48 h p.i. and reached 100% at the end of the plateau phase at 120 h p.i. Gross signs of white spots and reddish discoloration were also obvious in moribund individuals from the plateau phase. Based on the three phases of viral growth, WSSV infection was classified into light, moderate and heavy infection stages.
Phenotypic and genotypic characterization of Flavobacterium psychrophilum from Finnish fish farms
Authors: Madetoja J , Hänninen M‐L , Hirvelä–Koski V , Dalsgaard I , Wiklund T
Published: March 2003

Finnish isolates (n=37) of Flavobacterium psychrophilum isolated from farmed salmonids were studied using phenotypic and genotypic characteristics. The characteristics of isolates were compared with the characteristics of Swedish and Estonian F. psychrophilum isolates and the type strain, F. psychrophilum NCIMB 1947T. Multiple isolates from eight disease outbreaks were examined to determine differences between isolates from a single outbreak. The F. psychrophilum isolates represented a biochemically homogeneous group. However, some minor differences in biochemical and physiological characteristics were observed. Seven different antigenic patterns among Finnish isolates were detected and the results suggest a new serotype of F. psychrophilum. Using ClaΙ, HaeΙΙΙ and PvuΙΙ restriction enzymes in ribotyping analyses 13 different genotypes were demonstrated and a possible relationship between serotype Fd and genotype F1 was determined. There were no significant differences between the isolates from Finland, Estonia, Sweden and the type strain of F. psychrophilum.
The retrospective evaluation of a general practitioner exercise prescription programme
Authors: Martin  , Woolf‐May
Published: March 2003

Aim: The purpose of this retrospective evaluation was to examine the characteristics of men and women who embarked upon a 10‐week general practitioner (GP) referral exercise prescription programme and to compare those who completed a 10‐week programme of exercise (Finishers) with those who failed to complete (Non‐finishers).

Methods: Forty‐two Finishers (16 males and 26 females) and 35 Non‐finishers (12 males and 23 females) were followed up with a semistructured telephone interview. Clinical data were also collected from the patients’ GPs’ case notes and the data were analysed using both quantitative and qualitative methods.

Results: Baseline results using one way
anova showed no statistical difference between the groups for age (P > 0.3), BMI (P > 0.9), Systolic BP (P > 0.9), Diastolic BP (P > 0.9), total cholesterol (P > 0.1), number of coronary heart disease (CHD) risk factors (P > 0.4), number of subjects with CHD family history (P > 0.7) or for number of smokers (P > 0.9). However, generally the females were younger than the males (males 57.9 ± 12.1 years, females 50.7 ± 13.3 years). Analysis of the available data from the case notes showed that (CHD)/coronary vascular disease (CVD) risk factors were not generally taken into account by the primary health care team to make appropriate referrals. Finishers attended the gym significantly (P < 0.0001) more times per week than the Non‐finishers (F 2.5 ± 0.9, NF 1.7 ± 0.6 sessions/week). Results from the semistructured interviews revealed that Finishers were less reliant on social support and more likely to report tangible health benefits whereas Non‐finishers relied on support of others when attending the gym.

Conclusions: Results from this evaluation suggest, that the methodology used was too crude to accurately measure the complex characteristics which determine the differences between Finishers and Non‐finishers.
A patient with Alzheimer’s disease, fed via percutaneous endoscopic gastrostomy, with personal reflections on some of the ethical issues arising from this case
Authors: Barratt J.
Published: March 2003

Dementia is a common condition which is often complicated by difficulties with eating and drinking, including dysphagia. This case study describes the management of the dysphagia of an elderly woman with Alzheimer’s disease and her eventual feeding via percutaneous endoscopic gastrostomy. Some of the ethical issues arising from the case are discussed, including enteral nutrition in dementia care, resource allocation and the consequences of not using nonoral feeding to manage dysphagia.
Investigation into the suitability and accessibility of catering practices to inpatients from minority ethnic groups in Brent
Authors: Hartley B. A. , Hamid F.
Published: March 2003

Background

The Borough of Brent has one of the largest ethnic minority populations in England, with a growing number of refugee communities from Africa and Europe. Two important issues to be considered when developing culturally sensitive services in the hospital (including food provision) are that practices meet the religious and cultural requirements of the population that the hospital serves and that staff are equipped with the skills to understand cultural differences in illness and treatment.

Aims

To review accessibility and suitability of multicultural meals to minority ethnic communities across five hospital sites in Brent and determine the level of nursing staff knowledge of multicultural dietary competencies.

Methods

One survey was completed in each of the five hospital sites to gather information about current catering practices. Two separate questionnaires obtained information of the level of inpatient satisfaction with multicultural meals amongst Hindu, Muslim, Caribbean and Jewish patient groups and knowledge of nursing staff about multicultural competencies. Community groups representing minority ethnic populations participated in focus groups to establish feedback about dietary requirements in hospitals.

Results

Access to multicultural meals varied across hospital sites. Of 98 patients in the inpatient satisfaction survey, 74% were aware of the availability of multicultural meals with 51% of these patients not ordering any of the Asian vegetarian, Asian halal, Caribbean or kosher meals, citing satisfaction with European food as the main reason. Those ordering multicultural meals reported satisfaction most of the time (42%), satisfied most of the time (38%) and never satisfied (19%). The African Muslim group was the least satisfied with current halal meal provision. Forty‐seven per cent of nurses questioned could accurately answer questions about multicultural dietary competencies.

Conclusions

Improvements could be made to improve accessibility and improve suitability of meal choices to inpatients from minority ethnic groups.
The relationship between psychiatric and physical health in elderly people with intellectual disability
Authors: Cooper S.‐A.
Published: March 2003

Elderly people with intellectual disability have high rates of both psychiatric and physical disorders. In the elderly general population, these disorders are known to be associated. Whether such an association exists amongst elderly people with intellectual disability is unclear, but the resolution of this question is of clinical as well as academic importance. Psychiatric and physical assessments were completed on 134 people with intellectual disability aged 65 years and over (93.7% of the ascertained population living in Leicestershire, UK). The relationship between the two disorders was statistically examined. The number of physical disorders, age, level of intellectual disability and smoking status were retained in the logistic regression equation which predicted caseness for dementia in 79.9%. Similar statistical modelling for psychiatric disorders (other than dementia) retained the level of intellectual disability as the only explanatory variable in the equation. These results differ from the elderly general population, but are in keeping with the one previous intellectual disability study. In view of the poor use of general medical services by elderly people with intellectual disability, knowledge of such comorbidity should alert psychiatrists to the need for physical assessments in order to optimize health.
Pathological and neuropathological findings in two males with fragile‐X syndrome
Authors: Sabaratnam M.
Published: March 2003

The present paper addresses post mortem pathological and neuropathological findings in two males with fragile‐X syndrome, aged 67 and 87 years. Both subjects died from sudden, unexpected cardiovascular causes, and both showed abnormalities of the mitral valve, ventricular hypertrophy and cardiomegaly. Both cases demonstrated macrocephaly characteristic of the classical Martin–Bell phenotype in FRAXA. There was increased brain weight in both cases: macroscopically, both cerebral and cerebellar hemispheres appeared normal, but dilated lateral ventricles were seen; and microscopic examination of the brain in case 2 showed normal hexalaminar architecture and no gross neuronal dropout. The hippocampus showed mild CA4 pyramidal cell loss and associated gliosis. The cerebellum showed focal Purkinje cell loss and corresponding Bergmann gliosis. Whilst there is a need to delineate the microscopic features of fragile‐X syndrome from those of the ageing process, there is an urgent need for more systematic neuropathological studies of fragile‐X syndrome; the increased brain weight and Purkinje cell loss in autism and fragile‐X syndrome reopens the debate on these two conditions. The case for further research into the cardiac anomalies in fragile‐X syndrome is also strengthened by the findings. Finally, the present report confirms the role of interstitial cell hyperplasia as the major cause of megalo‐testes in this condition.
Celiac disease and alopecia areata in a child with Down’s syndrome
Authors: Storm W.
Published: March 2003

According to recent reports in the literature, there seems to be an association between alopecia areata and celiac disease. The present author describes a 9‐year‐old girl with Down’s syndrome, and alopecia areata, and documented celiac disease, who displayed a normal growth of hair after a gluten‐free diet. Given the high prevalence of these two diseases in patients with Down’s syndrome, the present author recommends both serological screening for celiac disease in every individual with Down’s syndrome, and in particular, the inclusion of such screening in any diagnostic work‐up for alopecia areata.
Prevalence, morbidity and service need among South Asian and white adults with intellectual disability in Leicestershire, UK
Authors: McGrother C. W. , Bhaumik S. , Thorp C. F. , Watson J. M. , Taub N. A.
Published: March 2003

Background Previous reports have suggested that South Asian and white UK populations have different prevalences of intellectual disability (ID), related psychological morbidity and service use. The aim of the present study was to compare these rates among South Asian and white adults in Leicestershire, UK.

Method This cross‐sectional study is comprised of two parts. The analysis of prevalence is based on data from all South Asian and white adults known to the Leicestershire Learning Disabilities Register in 1991, with population denominators being drawn from the 1991 census. The other analyses use data collected from the most recent semi‐structured home interviews, carried out between 1987 and 1998, with 206 South Asian and 2334 white adults.

Results The prevalence of ID in adults in Leicestershire is 3.20 per 1000 in South Asians and 3.62 per 1000 in whites. Among adults with ID, South Asians have similar prevalences of disabilities to whites and significantly lower skill levels. South Asians show similar levels of psychological morbidity, but make significantly lower use than whites of psychiatric services, residential care and respite care. South Asians use community services as extensively as whites, but feel that they have a substantially greater unmet need, especially with regard to social services.

Conclusion South Asian and white populations have similar prevalences of ID and related psychological morbidity. Culturally appropriate services for South Asian adults may need to focus on skill development and community care.