bluuebunny/crossref_metadata_2025 huggingface dataset:
Size and spatial pattern of Festuca rubra genets in a mountain grassland: its relevance to genet establishment and dynamics
Authors: Suzuki Jun‐Ichirou , Herben Tomáš , Krahulec František , Hara Toshihiko
Published: March 2003

1 For many clonal plant species, the density of shoot populations makes it almost impossible to determine genet natality directly. We identified genets by a randomly amplified polymorphic DNA (RAPD) method and used their size and spatial pattern, together with demographic parameters (genet spreading rate and mortality rate of shoots) determined in the field to estimate natality rates for Festuca rubra (red fescue).

2 In each of two sites (a species‐rich and a species‐poor site in a mountain grassland) three plots were established. Each plot contained two 1 m × 3.3 cm transects, composed of 3.3 × 3.3 cm square cells. Estimates of genet number per plot (18–49 and 27–33, respectively, in the two sites) were based on a randomization test. Mean genet size (1.2–1.6 cells) was not significantly different between the sites, nor was the spatial pattern of genets significantly different from random at either site. Interactions between genets therefore appeared to be negligible.

3 A spatial simulation model was developed for the genet population. Values estimated from the growth and demographic data over several years for the genet spreading rate (0.2–0.3) and for the mortality rate of shoots per cell (0.2–0.3) were among those used in the simulation. When a constant genet natality rate of 3–7 genets m–2 year–1 was included in the model, the simulation generated numbers and size frequency distributions of genets that were similar to those found in the field.

4 In this mountain grassland, F. rubra appeared to show repeated seedling recruitment, instead of the initial seedling recruitment following disturbance that is thought to be typical of many grasses. Founder effects were immaterial at the rates of seedling recruitment apparent in these populations. A stable population was achieved with the values of genet spreading rate and mortality rate of shoots per cell observed in the field, and repeated seedling recruitment. However, genet natality rates may vary if environmental conditions fluctuate.
Life span and biomass allocation of stunted black spruce clones in the subarctic environment
Authors: Laberge Marie‐Josée , Payette Serge , Bousquet Jean
Published: March 2003

1
 Slow growth, maintenance of a high leaf : wood ratio and adoption of a clonal growth habit, more than size per se, may increase the life span in trees species. The longevity of black spruce (Picea mariana (Mill.) BSP.) is increased from 200 to 300 years, when it grows as a clonal shrub.

2
 We measured the surface area and above‐ and below‐ground biomass of 25 postfire, stunted black spruce clones identified from RAPDs markers. The maximum age of each clone was deduced from tree‐ring dating or by radiocarbon dating of charcoal fragments. The oldest clone was > 1800 years of age. The total surface area of the clones increased with age, ranging from 2.8 to 691.3 m2. The ratio of living aerial parts to the total surface area decreased from 100% to < 50% with postfire stand age, reflecting fragmentation of clones into many autonomous or potentially autonomous rooted branches (layers). The number of layers increased with age from 12 layers in a 100‐year‐old individual to more than 80 in a 1800‐year‐old clone.

3  Biomass allocation and fragmentation can explain the maintenance of a relatively stable leaf : wood ratio of approximately 10% through time in stunted black spruce clones. The fragmentation of layers is the main mechanism ensuring the great longevity of prostrate clones in exposed sites. In the absence of perturbation, stunted black spruce clones may perpetuate for centuries or even millennia.
Lower limits of Spartina densiflora and S. maritima in a Mediterranean salt marsh determined by different ecophysiological tolerances
Authors: Castillo J. M. , Fernández‐Baco L. , Castellanos E. M. , Luque C. J. , FigUeroa M. E. , Davy A. J.
Published: March 2003

1 Salt marshes in south‐west Spain are being invaded by Spartina densiflora, a South American introduction, although the native S. maritima still dominates many lower marshes. A transplant experiment was used to investigate the means by which physical and chemical factors may determine lower vegetation limits in the tidal frame. Both species were transplanted from a mid‐level marsh to lower, unvegetated tidal flats.

2 The survival and growth of transplanted clumps and their constituent tillers were monitored on an elevational gradient. The photosynthetic competence of transplants was assessed by measurements of leaf gas exchange and the fast kinetics of chlorophyll fluorescence. Submergence period, salinity, redox potential and sulphide concentration in the sediment were also examined at the transplant sites.

3 Neither species survived for a year at the lowest transplant point (+ 1.04 m relative to Spanish Hydrographic Zero). At + 1.41 m elevation, S. maritima survived well but all clumps of S. densiflora died. At higher elevations (+ 1.46–1.67 m), clumps of both species had high survival rates. Tiller growth rates in surviving clumps of both species increased with elevation, but that of S. densiflora was more sensitive to low elevation.

4 S. maritima showed no impairment of photosynthetic performance, even at the lowest elevation; its rates of gas exchange were independent of elevation, as were its chlorophyll fluorescence parameters. In contrast, in S. densiflora the rate of CO2 uptake declined and stress to photosystem II (Fv/Fp) increased at lower elevations; both of these photosynthetic measurements were linearly related to sediment redox potential. Stomatal conductance did not vary with elevation.

5 S. maritima has a potentially wide elevational tolerance and an absolute lower limit substantially below that of S. densiflora. The progressively reduced growth and survival of S. densiflora at lower levels appear to result primarily from impairment of photosynthesis when root conditions are hypoxic. This effect is mediated through effects on the photochemical apparatus rather than on stomatal resistance to CO2 uptake.

6 These studies define lower limits to the fundamental niches of the two species in a Mediterranean‐type salt marsh and thus provide a basis for future investigations of interactions between them. The correlation between chlorophyll fluorescence and long‐term survival of S. densiflora suggests that this short‐term measure may be a valuable tool.
Leaf area renewal, root retention and carbohydrate reserves in a clonal tree species following above‐ground disturbance
Authors: Landhäusser Simon M. , Lieffers Victor J.
Published: March 2003

Removal of the above‐ground portion of clonally regenerating trees results in a massive imbalance in the ratio of root to leaf area. We investigated the resilience of clones following above‐ground disturbance in terms of root carbohydrates, leaf area renewal and root retention.

In a 2 × 2 factorial experiment, 40 Populus tremuloides saplings were cut at times of high (late fall) or low (spring after leaf flush) root carbohydrate reserves. Leaf area renewal was manipulated by allowing either only one or all root suckers to re‐grow.

Root starch concentrations were 10 times higher at the time of cutting in the fall compared with the spring, whereas sugar concentrations were only 10% higher. When saplings were cut in fall and all suckers were allowed to develop (FA treatment), suckers were taller, and had more biomass and leaf area and higher leaf area ratio than all other treatments. In particular, leaf area and leaf area ratio recovered within a year to near pre‐treatment levels compared with at least a 50% reduction in the other treatments.

At the end of the first season after cutting FA saplings also had the greatest root mass and lowest amount of dead root mass, and root starch concentrations of these saplings had returned to pre‐treatment values, compared with a 20% recovery for spring‐cut saplings with a single sucker. Root mass and root starch concentrations were correlated with leaf mass in all treatments.

Adequate carbohydrate reserves at the time of disturbance and rapid redevelopment of leaf area by extensive sprouting seem critical for resilience of the clone and allow for the retention of the clonal root system and a rapid rebuilding of carbohydrate reserves. Clones with poor sucker and leaf area development showed extensive root mortality and reduced carbohydrate reserves and their prospects for growth in the following year were comparatively poor.
Experimental assessment of Heliconia acuminata growth in a fragmented Amazonian landscape
Authors: Bruna Emilio M. , Nardy Olavo , Strauss Sharon Y. , Harrison Susan
Published: March 2003

Fragmentation severely alters physical conditions in forest understories, but few studies have connected these changes to demographic impacts on forest species using detailed experimental examination at the individual and population levels.

Using a 32‐month, reciprocal‐transplant experiment, we show that individuals of the Amazonian understory herb Heliconia acuminata transplanted into forest fragments lost over 20% of their vegetative shoots, while those transplanted to continuous forest showed a slight gain. The leaf area of plants in fragments also increased at half the rate it did in continuous forest sites.

It appears that the normal dry season stresses to which forest understorey plants are exposed are greatly exacerbated in fragments, causing plants to shed shoots and leaves.

The observed shifts in size could help explain why populations in fragments are more skewed towards smaller demographic stage classes than those in continuous forest. These shifts in size structure could also result in reduced abundances of flowering plants, as reproduction in H. acuminata is positively correlated with shoot number.

Fragmentation‐related changes in growth rates resulting from abiotic stress may have significant demographic consequences.
Patterns of invasion within a grassland community
Authors: Kolb A. , Alpert P. , Enters D. , Holzapfel C.
Published: March 2003

Relatively few studies have looked for patterns of invasion by non‐native species within communities. We tested the hypotheses that: (i) some types of microhabitats within a community are more invasible than others; (ii) microhabitat types that differ in invasion also differ in resource availability; and (iii) invasibility is mediated by effects of these resources on competition between native and non‐native species.

To test the first two hypotheses, we measured plant cover and soils in a coastal grassland in northern California. Consistent with these hypotheses, cover of non‐native plants was consistently high where nitrogen‐fixing shrubs had recently grown, in the bottoms and sides of gullies and on deep soils, and these microhabitats tended to have relatively high nitrogen or water availability.

Cover and number of native species tended to be lower where cover of non‐native species was higher, indicating that non‐native species as a group negatively affected native species. However, the number of non‐native species also tended to be lower where the total cover of non‐natives was higher. This suggests that a few non‐native species excluded natives and other non‐natives alike.

To test the third hypothesis, we grew a common non‐native, the annual grassLolium multiflorum, and a common native, the perennial grassHordeum brachyantherum, at different levels of water and nitrogen. The relative competitive ability of the native was higher at lower nitrogen availability but not at lower water availability. When 10‐week‐old native plants were grown with non‐native seedlings and nitrogen was relatively low, the native out‐competed the non‐native. However, the non‐native out‐competed the native at all resource levels when species were both grown as seedlings. Competition between native and non‐native grasses in this system may thus help prevent invasion by non‐natives in microhabitats where nitrogen availability is low, but invasion may be relatively irreversible.
Methodological limitations of cost‐effectiveness analysis in health care: implications for decision making and service provision
Authors: Raftery James
Published: March 2003

This article reviews the methodological limitations identified in a recent authoritative US report by the Public Health Service, which provides the theoretical background to several other guidelines on cost effectiveness, such as those of the British Medical Journal. It places each limitation in context and discusses the implications of each individually and collectively. It concludes that while the report’s interim solution by consensus agreement offers a way forward in the short term, the complexities identified reveal a range of limitations to the more heroic uses of cost effectiveness analysis in healthcare. More modest approaches, it is suggested, may have greater practical relevance.
A critical evaluation of clinical practice guidelines in neonatal medicine: does their use improve quality and lower costs?
Authors: Merritt T. Allen , Gold Marjorie , Holland Jodi
Published: March 2003

Clinical practice guidelines and care pathways have become a focus of quality improvement efforts in Neonatology. Health care administrators believe that using clinical practice parameters reduces health care costs, improves quality of care, and limits malpractice liability. Practice guidelines and surveys of consumer satisfaction have grown in use partly because third‐party payers, insurers, and health maintenance organizations, as well as hospital administrators bent on reducing variable costs of care and contracting for capitated care have championed their development, implementation, and monitoring. Overall there is minimal evidence‐based medicine to support that neonatal outcomes have benefitted from their implementation, although some studies show affirmative effects in limited populations or in a limited number of centres. For highly autonomous physicians and nurses this standardization of medical decision making may represent a difficult transition into efforts to improve quality, based on evidence‐based care, and in some instances into corporate medicine. By realigning the traditional values of patient relationships, including parent involvement, the implementation of guidelines has been fast‐tracked in some institutions, without appropriate audit to determine their effectiveness in achieving their goals. However, because guidelines and clinical pathways are here to stay, neonatologists need to think critically about how their content and method of implementation, monitoring and modification may influence medical and nursing teaching and decision making in the future. If guidelines are introduced primarily as a cost savings or containment tool that ignores their impact on the quality of medical care and thereby restricts needed care, then neonatologists must be quick to challenge the potentially damaging and inappropriate use of guidelines and care pathways. Several international efforts are underway to study both the impact of evidence‐based guidelines and to determine if they can be imported from one care system into another. Furthermore, there are many medico‐legal implications of guideline and clinical pathway implementation that may not favour physicians and other neonatal care practitioners, and leave to hospitals, insurers, and ultimately the courts, decisions regarding evidence‐based care. Neonatologists and other practitioners in neonatal care centres should critically analyse the goals of guideline development, implementation and monitoring and should restrict themselves to guideline directed care only at those practices for which there is evidence supporting their implementation and continuous monitoring.
Challenges in using rater judgements in medical education
Authors: A. Albanese Mark
Published: March 2003

Changes in the healthcare environment are putting increasing pressure on medical schools to make faculty accountable and to document the quality of the medical education they provide. Faculty’s ratings of students’ performances and students’ ratings of faculty’s teaching are important elements in these efforts to document educational quality. This article discusses selected research related to factors affecting raters’ judgements, analyses how changes in the health care environment are influencing such judgements, offers some suggestions to moderate some of the effects and links these influences to the system that upholds professional standards. Ratings are known to have a positive bias (generosity error), provide limited discrimination and often fail to document serious deficits. The potential sources of these problems relate to the mechanics of the rating task, the system used to obtain ratings and factors affecting rater judgement. As managed care demands reduce the time faculty have for teaching, as system‐wide disincentives to provide negative ratings proliferate and as social engineering challenges, such as the Americans with Disabilities Act, impose differential standards for students, the natural tendency to avoid giving negative ratings becomes even harder to resist. Ultimately, these forces compromise the capability of faculty to uphold the standards of the profession. The author calls for a national effort to stem the erosion of those standards.
Improving the quality of care of patients with asthma: the example of patients with severely symptomatic disease
Authors: Liu Xiaofeng , Farinpour Roxanna , Sennett Cary , PharmD Brian W. Bowers , Legorreta Antonio P.
Published: March 2003

The increasing economic burden of asthma care is incurred partly by patients with more severe symptoms. However, little is known about the characteristics of these severe asthma patients. This study examined sociodemographic, disease‐specific characteristics and health care utilization that are related to asthma disease severity, for the purpose of identifying areas for treatment improvement. A total of 2927 asthma patients (12 years or older), who were continuously enrolled in one of three participating health plans for a 6‐month study period and who responded to an asthma survey, were included in the study. Univariate and multivariate analyses were performed to examine the sociodemographic, disease‐specific characteristics and health care utilization by asthma severity. About 25% of the patients reported experiencing severe asthma symptoms. They were more likely to be African‐Americans, Hispanics, women, patients with less than a college education, residents in the south‐west, current smokers, and those receiving care from non‐specialists. Severe asthmatics reported having less of an understanding of the clinical manifestation of asthma and the means to manage asthma exacerbation. Outpatient contacts did not differ significantly between severe and other patients, although their utilization of emergency room and inpatient care was significantly greater. This study suggests that a significant proportion of asthma patients is experiencing severe symptoms and barriers other than access to care prevent appropriate control of asthma. Poor control appears to be related to smoking, deficits in knowledge about self‐care, not receiving medical care from a specialist, and inadequate use of medications.
Towards case‐based performance measures: uncovering deficiencies in applied medical care
Authors: Hoelzer Simon , Waechter Werner , Stewart, Andrew , Liu, Raymond , Schweiger Ralf , Dudeck Joachim
Published: March 2003

Measures are designed to evaluate the processes and outcomes of care associated with the delivery of clinical (and non‐clinical) services. They allow for intra‐ and interorganizational comparison to be used continuously to improve patient health outcomes. The use of performance measures always means to abstract the complex reality (medical scenarios and procedures) in order to provide an understandable and comparable output. Measures can focus on global performance. The more detailed data are available the more specific judgements with respect to the appropriateness of clinical decision‐making and implementation of evidence are feasible. Externally reported measures are intended both to inform and lead to action. By providing this information, deficiencies in patient care and unnecessary variations in the care process can be uncovered. Such variations have contributed to disparities in morbidity and mortality. The developments in information technology, especially world‐wide interconnectivity, standards for electronic data exchange and facilities to store and manage large amounts of data, offer the opportunity to analyse health‐relevant information in order to make the delivery of healthcare services more transparent for consumers and providers. Global performance measures, such as the overall life expectancy (mortality) in a country, can give a rough orientation of how well health systems perform but they do not offer general solutions nor spe‐cific insights into care processes that have to be improved. In contrast to population‐based measures, case‐based performance measures use a defined group of patients depending on specific patient characteristics and features of disease. By means of these measures we are able to compare the number of patients that receive a necessary medical procedure against those patients who do not. The use of case‐based measures is a bottom‐up approach to improve the overall performance in the long run. They are not only a tool for global orientation but can offer a straightforward link to the areas of deficient care and the underlying procedures. Performance measures are relevant to providers as well as consumers, from their own individual perspective. Cased‐based measures focus on the management of individual patient. This approach to performance measurement can inform physicians in a meaningful and constructive way by monitoring their individual performance and by pointing out possible areas of improvement.
Data, information and knowledge: the health informatics model and its role in evidence‐based medicine
Authors: Georgiou Andrew
Published: March 2003

The health informatics model consists of three essential parts: data, information and knowledge. These elements are arranged in a hierarchy, with data at the base of the model providing the basis for establishing information and leading in turn to the potential generation of knowledge. The informatics model converges closely with the principles, aims and tasks of evidence‐based medicine (EBM), particularly as they relate to searching, appraising, reviewing and utilizing information and research. The development of health informatics today has its origins in the growth of statistics in the 18th and 19th centuries. As a new and growing discipline, statistics burgeoned amidst the challenge of measuring, monitoring and ultimately governing societies in the throes of massive change and expansion. The governance role embraced by statistics in the past resembles many aspects of the role ascribed to audit, quality assurance and EBM today. There are some deep‐seated paradoxes within the field of health informatics. The informatics model posits an oversimplified and linear progression of data to information and knowledge. Health informatics may involve the spreading and dissemination of information but this should be seen as only a part, not the equivalent, of the complex process of generating knowledge.
Actin rearrangements accompanying Aeromonas hydrophila entry into cultured fish cells
Authors: Low  , Goh  , Lim  , Sin  , Leung
Published: March 2003

Aeromonas hydrophila can enter fish cells and exist as intracellular parasites. Phase‐contrast and confocal microscopy were used to examine morphological changes and various cytoskeletal components of infected fish cells. Four fish cell lines were included in this study: (1) AS, (2) BF2, (3) CHSE‐214, and (4) EPC cells. Virulent but not avirulent strains of A. hydrophila PPD 134/91 invaded fish cells, causing morphological changes, and inducing microfilament (F‐actin) rearrangement. Morphological changes were observed in all infected fish cell lines and could be classified into three different stages. In stage I, the cells became detached from each other and pointed ends were observed. In stage II, tubular cytoplasmic extensions formed at contact points connecting neighbouring cells. The monolayers formed a satellite‐like organization and became less confluent. Finally (stage III), cells were heavily infected with bacteria, and bacteria containing vacuoles occupied most of the cells. They eventually detached and lysed. Rearrangement of F‐actin was observed as local polymerization (actin clouds) in stage I and massive reorganization in stage III of infection. Actin clouds could have been induced by A. hydrophila for ‘assisted' uptake into the cells. The massive reorganization of actin in stage III may be due to products released by the bacteria and the growth of vacuoles. Pretreatment of fish cells with the microfilament inhibitors such as cytochalasins induced a similar effect. There were little if any rearrangements in intermediate and microtubule filaments during bacterial entry (stages I and II). These results suggest that A. hydrophila may bind to the surface and trigger a signal to the microfilament which then generates the force necessary for bacterial uptake.
Isolation and characterization of the causative agent of pasteurellosis, Photobacterium damsela ssp. piscicida, from sole, Solea senegalensis (Kaup)
Authors: Zorrilla I. , Balebona M. C. , Mori·igo M. A. , Sarasquete C. , Borrego J. J.
Published: March 2003

The first description of pasteurellosis affecting sole, Solea senegalensis (Kaup), cultured in the South‐west of Spain is reported. Diseased fish showed no apparent lesions except for a dark skin pigmentation and swelling in the abdominal cavity. Internally, affected specimens showed paleness of liver and kidney and typical white tubercles of 1–2 mm in diameter in the spleen. Microbiological analysis of these fish revealed the presence, in pure culture from all the organs examined, of one type of bacterial colony which was biochemically and serologically characterized as Photobacterium damsela ssp. piscicida. The sensitivity pattern to antimicrobials and the enzymatic activities of the bacterial extracellular products are described.
Myxosporean infection causing intestinal disease in farmed turbot, Scophthalmus maximus (L.), (Teleostei: Scophthalmidae)
Authors: Branson E. , Riaza A. , Alvarez‐Pellitero P.
Published: March 2003

The present report describes an intestinal disease which causes important losses in farmed turbot. Mortality rates were higher in summer and reached 100% in all tanks where the disease was confirmed. Affected fish showed external signs consisting of anorexia, sunken eyes and a typical prominent bony ridge on the skull. These signs can be considered the pathognomonic signs of the disease, together with the gut lesions seen in the histological study. Pallor of the internal organs, intestinal haemorrhages and the presence of liquid in the intestine were also observed, with ascites in heavily infected fish. Histopathological damage was evident in the gut, with severe enteritis, detachment of epithelium, haemorrhages and inflammation of the subepithelial connective tissue. The myxosporean aetiology was demonstrated in all the fish showing the characteristic signs of disease. Myxosporean stages, including scarce spores, were found in the affected epithelium or free in the intestinal lumen together with epithelial debris. The present study demonstrates the importance of this myxosporean disease which represents a serious threat for turbot culture. This is also the first record of a member of the Myxosporea in turbot.
Nocardiosis in sea bass, Lateolabrax japonicus, in Taiwan
Authors: Chen S‐C , Lee J‐L , Lai C‐C , Gu Y‐W , Wang C‐T , Chang H‐Y , Tsai K‐H
Published: March 2003

An epizootic in pond cultured sea bass, Lateolabrax japonicus, was caused by Nocardia sp. in Taiwan, in September and October 1997. The cumulative mortality within 1 month was 17.5% (3500 out of 20 000 fish) and diseased fish were 7 months old with total lengths from 25 to 30 cm. Multiple, yellowish white nodules, 0.1–0.2 cm in diameter, were scattered in the gill, heart, liver, spleen and kidney. Histopathologically, typical granulomatous lesions appeared in those organs. The morphology of isolated bacteria from brain heart infusion (BHI) medium or Lowenstein–Jensen medium (LJM) were bead‐like filaments, as shown by Ziehl‐Neelsen's (ZN) staining method. The gross lesion and histopathological changes found in experimentally infected fish were similar to those in naturally infected fish. Based on the growth characteristics, morphological and biochemical properties of the bacterium, and histopathological changes, the isolated bacteria were identified as Nocardiaseriolae. This is the first report of N. seriolae‐infected sea bass in aquaculture.
BiographyBiography
Authors: Hoffman Glenn Lyle
Published: March 2003

Glenn Lyle Hoffman, the son of Ernest J. and Viola M. Hoffman, was born on a small farm in Iowa on December 28, 1918. He is a graduate of Lamont High School in Iowa where he excelled at wrestling. In 1942, he received a B.A. Degree from the University of Iowa, majoring in Zoology. He paid his own way through college by trapping fur animals, washing hospital windows, and working summers at a trout hatchery for the Iowa Department of Natural Resources.
Altered tissue distribution of Loma salmonae: effects of natural and acquired resistance
Authors: Sanchez J G , Speare D J , Markham R J F
Published: March 2003

This study compared and contrasted the fate of the microsporidian Loma salmonae, a branchial pathogen of salmonids of the genus Oncorhynchus, upon exposure of (1) naive susceptible rainbow trout (RT) O. mykiss, (2) naive RT passively immunized with sera from RT previously exposed to L. salmonae, (3) previously exposed and resistant RT and (4) two species believed to be innately resistant to the parasite, Atlantic salmon (AS) Salmo salar and brook trout (BT) Salvelinus fontinalis. The fish were infected per os with viable L. salmonae spores. The infection was followed in the fish by detection of parasite DNA by polymerase chain reaction (PCR) at several times post‐infection. Spore germination and intestinal invasion by the parasite occurred in all groups of fish. In the susceptible RT, parasite DNA was detected in the heart by day 3 post‐exposure (PE), followed by the gill at 2 weeks PE, whereas visible xenoparasitic complexes (xenomas) were detected by week 4 PE. In the passively immunized RT, the parasite’s fate was similar to that of controls, however, its arrival in the heart was delayed by 1 week. A delay was also detected in RT which had been previously exposed to L. salmonae and then recovered from disease. In these resistant fish, the parasite was able to reach the heart by week 3 PE, however, it failed to reach the gill and form xenomas. In AS and BT, the parasite reached the heart and gills quickly, where it remained for 2 weeks before being cleared; xenomas never formed. We speculate that failure to complete the life cycle in AS, BT and resistant fish might be because of interference by the immune system in the development of the parasite, resulting in the absence of disease in these fish.
Distribution and structure of lesions in the gills of Atlantic salmon, Salmo salar L., affected with amoebic gill disease
Authors: Adams M B , Nowak B F
Published: March 2003

Gills of Atlantic salmon, Salmo salar L., with amoebic gill disease (AGD), were analysed by routine histology to identify lesion morphology and distribution patterns. Numbers of lesions occurring dorsally, medially and ventrally in the gill filaments were recorded as was lesion size, proximity to the gill arch and the degree of pathological severity involved. The mean number of lesions and pathological severity in the dorsal region of the second left gill arch were significantly higher than that found ventrally (P < 0.01). There were no significant differences between gill regions in lesion size or proximity of lesions to the gill arch. Serially sectioned lesions revealed interlamellar cysts to be spherical to ovate in shape and fully enclosed within a wall of epithelium. Small to medium size cysts sometimes contained necrotic amoebae. Inflammatory cells, morphologically identified as neutrophils and macrophages, were occasionally seen infiltrating medium sized cysts. Larger cysts were mostly clear of any cellular debris.
Development of a reproducible infectious pancreatic necrosis virus challenge model for Atlantic salmon, Salmo salar L.
Authors: Bowden T J , Smail D A , Ellis A E
Published: March 2003

Atlantic salmon smolts, previously unexposed to infectious pancreatic necrosis virus (IPNV), were placed into tanks of sea water at 10 °C. After 4 weeks, 40 fish were injected intraperitoneally (i.p.) with homogenized and filter‐sterilized kidney material obtained from salmon with clinical IPN in a marine farm in Shetland. The injected fish were cohabited with 40 untreated fish. Mortalities began in the injected fish on day 7 and reached a peak of 48% on day 14. In the cohabitation group, mortalities began on day 14 and reached a peak of 70% on day 27. The IPNV in the Shetland kidney homogenate was cultured in Chinook salmon embryo (CHSE) cells and passed twice. This cultured virus was injected i.p. into fish at various doses ranging from 10 to 107 TCID50 fish−1 4 weeks after seawater transfer. Challenge tanks contained 30 injected fish and 30 cohabitees. Mortality rates and levels were dose‐dependent. The highest dose used resulted in a similar mortality pattern as obtained with a similar dose of the Shetland kidney homogenate, indicating that virulence was retained after two passes in tissue culture. Even with the lowest dose, mortality reached 12% in the injected group and 23% in the cohabitees. The IPNV titres were high (106−109 i.u. g−1 kidney) in fish which died during the experiment and low (<105 i.u. g−1 kidney) or undetectable in surviving fish. The cultured virus (pass 3) was used in a challenge model where the population density of fish in the tanks was high (50 injected and 50 cohabitees) or low (15 injected and 15 cohabitees). In the high stocking density tank, mortalities peaked at about 35% in the injected group and at 52% in the cohabitees. In the low stocking density tank, mortalities peaked at about 40% in the injected fish but no mortality occurred in the cohabitees. However, IPNV was detected (up to 104 i.u. g−1 kidney) in 82% of cohabitees sampled on day 30. These data suggest that lethal lateral transmission of the virus is dependent on the infectious pressure from the injected group. A further trial was conducted to investigate the effect of time post‐seawater transfer on the susceptibility of post‐smolts to IPN. Groups of fish were challenged every 2 weeks from week 0–10. Few mortalities occurred at week 0 and virus titres were high in these fish. Most survivors became carriers, some with titres >106 i.u. IPNV g−1 kidney. From 2 to 10 weeks after seawater transfer, mortalities in both injected and cohabitees were substantial with viral titres >107 i.u. g−1 kidney. Survivors had lower titres and in many virus was undetectable. Throughout the experiments, moribund fish were sampled for histology and all showed typical IPN histopathology.
The nutrient and food intakes of British male dieters aged 16–17 years
Authors: Crawley H. , Summerbell C.
Published: March 2003

Background: There is little information available about the dieting habits of teenage boys. This study aimed to examine the food and nutrient intake of male teenage dieters and compare these with the patterns reported among female dieters.Method: Male dieters aged 16–17 years were isolated from the 1970 Longitudinal Birth Cohort study group. Five hundred and one males who provided a 4‐day unweighed dietary diary, height and weight measurements and appropriate background information.Results: Thirty‐nine subjects (7.8%) both reported dieting and had a ratio of reported energy intakes to estimated basal metabolic rate measurements of less than 1.35. Dieters were taller and heavier than non‐dieters, with mean BMIs of 24.6 and 20.0, respectively, for the two groups. Dieters reported average energy intakes of 9.16 MJ/day compared to intakes of 12.83 MJ/day among non‐dieters, and the percentage of energy provided by protein was higher and that provided by NMES lower among dieters. Reported micronutrient intakes were lower among dieters, with calcium, magnesium, zinc, selenium, iodine, vitamin B6, vitamin C and retinol equivalents the nutrients most vulnerable to reduction in energy intakes. Dieters reported lower intakes of most food groups, but reported intakes of alcohol and meat and meat products were not reduced among dieters.Conclusion: Dieters clearly reported energy intakes which were unlikely to represent levels of intake sufficient to maintain existing weight. The nutrient and food intakes reported by the dieters were likely to reflect either true dieting behaviour during the study period, under‐reporting or a combination of these effects.
Integrating cognitive behavioural therapy into dietetic practice: a challenge for dietitians
Authors: Rapoport
Published: March 2003

Historically, State Registered Dietitians have not received in‐depth training in behaviour change skills. Training in this area has been viewed as peripheral rather than fundamental. Whilst a permanent long‐term cure for obesity remains elusive, cognitive behavioural therapy is state of the art in the treatment of obesity. It reliably achieves 10% pretreatment body weight loss in the short‐term. Interesting new developments are occurring in this field which may affect long‐term outcome favourably. This paper examines what can be achieved with traditional dietary therapy in the treatment of obesity, what can be achieved with cognitive behavioural therapy and considers whether dietitians should receive further training in key behaviour change theory and skills. It is recommended that the integration of the fields of nutrition and behavioural psychology is placed centrally on the agenda of State Registered Dietitians.
Prevalence of fragile‐X syndrome and FRAXE among children with intellectual disability in a Caribbean island, Guadeloupe, French West Indies
Authors: Elbaz A. , Suédois J. , Duquesnoy M. , Beldjord C. , Berchel C. , Mérault G.
Published: March 2003

Fragile‐X syndrome (FXS) is the most common cause of inherited intellectual disability. Although FXS has been identified in all the main ethnic groups, little is known about its prevalence with respect to ethnicity. Since the identification of the FXS primary defect, diagnosis involving DNA analysis has been made possible, allowing efficient screening strategies to be considered. The present authors have carried out FXS screening among children belonging mainly to the Afro‐Caribbean ethnic group (163 boys and 85 girls) affected with moderate to severe intellectual disability of previously unknown origin. We have found a 6.7% and 0% prevalence among boys and girls, respectively, yielding a minimum FXS incidence of 0.42 per 1000 male births per year. Family studies have resulted in genetic counselling for several individuals. FRAXE screening was also achieved and no FRAXE case was detected in this study.
Prader–Willi syndrome and psychotic symptoms: 2. A preliminary study of prevalence using the Psychopathology Assessment Schedule for Adults with Development Disability checklist
Authors: Bouras N. , Clarke D.
Published: March 2003

The Psychopathology Assessment Schedule for Adults with Developmental Disability (PAS‐ADD) checklist was used to screen for psychotic symptoms among people with Prader–Willi syndrome (PWS) aged 16 years and over. The scoring instructions for the PAS‐ADD checklist were modified to take account of knowledge about the behavioural phenotype of PWS. Using modified scoring, 6.3% of the 95 people for whom checklists were completed had a possible psychotic disorder in the month before the assessment was made. The results should be treated as a crude estimate of the prevalence of psychotic symptoms associated with PWS in adult life in view of potential biases in the sample reported. These findings lend some support to the hypothesis that PWS has a non‐chance association with psychotic symptoms and that the association is not entirely accounted for by the increased prevalence of psychosis associated with intellectual disability.
Characteristics of people with intellectual disability admitted for psychiatric inpatient treatment
Authors: Raitasuo S. , Taiminen T. , Salokangas R. K. R.
Published: March 2003

The present prospective study describes the demographic, medical and psychosocial characteristics of 40 people with intellectual disability who were referred for psychiatric inpatient treatment in the special psychiatric unit of the Special Welfare District of South‐west Finland. Three different control groups were used to study: (1) demographic variables (n = 122); (2) medical history (n = 39); and (3) psychosocial factors (n = 20). The symptoms leading to an admission to inpatient care and the connections of these clinical signs with the discharge diagnosis were evaluated. The typical inpatients were young males with mild intellectual disability, psychosis and a previous psychiatric diagnosis. They had lived in several places during their lives and their economic situation was poor. Affective and/or disruptive symptoms were the most common causes of an admission to inpatient care. The largest diagnostic group at discharge consisted of patients with psychotic disorders. The people with intellectual disability who were admitted for inpatient care formed a subgroup with certain psychiatric symptoms and social problems. Specialist psychiatric expertise is absolutely necessary for the treatment of this subgroup.
Long‐term follow‐up of behavioural treatment for primary encopresis in people with intellectual disability in the community
Authors: Huntley E. , Smith L.
Published: March 2003

Encopresis is a major problem in high‐dependency fields such as intellectual disability. Little information is available with respect to either the prevalence or aetiology of encopresis, probably because it is widely regarded as part and parcel of the handicapping condition. Consequently, treatment reports are rare and confined to a small number of case studies. There is a dearth of long‐term follow‐up on the behavioural treatment of encopresis in the general population, and no long‐term follow‐up studies are available for the treatment of encopresis in intellectual disability. The present report provides follow‐up data for nine out of 10 people with mainly severe intellectual disability who had received behavioural treatment for primary retentive or non‐retentive encopresis between 5 and 17 years previously. Six out of the nine subjects for whom data were available were accident‐free and a further two clients were very substantially improved. Interestingly, those whose former encopresis was retentive in nature maintained more successfully, despite the severity of their original impaction. The limitations of the present study are discussed.
Psychopathology of sexual abuse in young people with intellectual disability
Authors: Firth H. , Balogh R. , Berney T. , Bretherton K. , Graham S. , Whibley S.
Published: March 2003

The present study addressed two issues using a sample of child and adolescent victims and perpetrators of sexual abuse: (1) the extent of post‐traumatic stress disorder (PTSD) in the sample; and (2) the possible distinction between perpetrators whose motivations were sexually impulsive, and those who were controlling and abuse‐reactive. Retrospective case material from 43 cases (21 victims only, and 22 perpetrators, of whom 16 were also victims) provided the data. Post‐traumatic symptomatology was not common. Only one case of PTSD was found. Perpetrators could be distinguished by whether they had suffered sexual abuse alone, sexual and physical abuse, or neither. The proposed distinction between perpetrators received support. Sexual abuse directed at younger victims was associated with earlier experience of multiple forms of abuse. The present data does not support the view that post‐traumatic symptoms following victimization are a mediator of sexual abuse perpetration. It is argued that an elaboration of the Williams & New developmental model of perpetration better fits the data.
Predictors for attacks on people after deinstitutionalization
Authors: Nøttestad J. Aa. , Linaker O. M.
Published: March 2003

Background

The deinstitutionalization movement is presently spreading in Europe, but studies evaluating the effects of deinstitutionalization on behaviour disturbances among people with intellectual disability (ID) are inconclusive. The prevalence of aggressive behaviour among people with ID is high in both institutions and in community. Aggression and attacks on people are a significant problem for people with ID in both institutions and society. In the present paper, the authors focus on individuals who started attacking people after deinstitutionalization.

Method

The authors studied individual and environmental characteristics before and after deinstitutionalization to look for individual and environmental predictors for the development of aggression with the hope that some could be possible intervention points for preventive action. In an institution for people with ID, all who did not attack people before deinstitutionalization were included. The individuals who started attacking others after deinstitutionalization (n = 22) were the study group (group A) and those who did not (n = 42) comprised the control group (group B). The population was examined before and after deinstitutionalization. As far as possible the same methods were used at both occasions. The covariates included individual ones, such as mental health, behaviour disturbances and behaviour deficits, and environmental ones, such as caretaker education, caretaker:patient ratio, housing and leisure activities. Psychiatric disorders were identified in 1987 and 1995 with the Psychopathology Instrument for Mentally Retarded Adults (PIMRA), which was filled in by the caretakers.

Results

Group A showed significantly more self‐injurious behaviour (SIB) than group B in 1987. The sum of behaviour disturbances shown in the past year, attacks on property, SIB and other disruptive behaviours were also significantly higher in group A than in group B. The soundness scores on the PIMRA for the people in group A were lower than for the people in group B. Group A contained significantly fewer people without behavioural problems in the past year. The authors could not find any differences on other individual characteristics such as aetiologies of ID and behaviour deficits in 1987. The caretakers’ evaluations of the clients need for help, based on behaviour disturbances and mental health problems, were significantly higher in group A. The people in this study differed in age, gender and degree of ID from those in most other studies on ID and challenging behaviour.

Conclusion

The individual predictors for starting to attack others after deinstitutionalization were SIB, a slight load of other behaviour problems and a low soundness score on the PIMRA. The only environmental predictor was the caretakers’ evaluation of the subjects’ need for help caused by behaviour problems and mental illness. The authors could not identify possible preventive intervention points, neither individual or environmental, and therefore, further studies are needed.