Community variability and ecological functioning: 40 years of change in the North Sea benthos.

Using established associations between species traits (life history, morphological and behavioural characteristics) and key ecological functions, we applied biological traits analysis (BTA) to investigate the consequences of 40 years of change in two North Sea benthic communities. Ecological functioning (trait composition) was found to be statistically indistinguishable across periods that differed significantly in taxonomic composition. A temporary alteration to functioning was, however, inferred at both sampling stations; coinciding with the North Sea regime shift of the 1980s. Trait composition recovered after 1 year at the station located inside the grounds of a trawl fishery, whereas the station located outside the main area of fishing activity underwent a six-year period of significantly altered, and temporally unstable, trait composition. A further alteration to functioning was inferred at the fished station, when the population of a newly established species rapidly increased in numbers. The results suggest that density compensation by characteristically similar (redundant) taxa acts to buffer changes to ecological functioning over time, but that functional stability is subject to aperiodic disruption due to substitutions of dissimilar taxa or uncompensated population fluctuations. The rate at which ecological functioning stabilises and recovers appears to be dependent on environmental context; e.g. disturbance regime.

Assessing the sensitivity of habitats to fishing: from seabed maps to sensitivity maps.

In the Welsh part of the Irish Sea, a method was developed for assessing the sensitivity of different seabed habitats to existing fishing activities, across a range of potential fishing intensities. The resistance of 31 habitats and their associated biological assemblage to damage by 14 categories of fishing activity were assessed along with the rate at which each habitat would recover following impact (resilience). Sensitivity was scored based on a combination of the resistance of a habitat to damage and its subsequent rate of recovery. The assessments were based, wherever possible, on scientific literature, with expert judgement used to extrapolate results to habitat and gear combinations not directly examined in the published literature. The resulting sensitivity matrices were then subject to further peer review at a series of workshops. Following consensus on the habitat sensitivity, these data were combined with the most resolved sea-floor habitat maps. These habitat sensitivity maps can help inform the development of site-specific management plans, as well as having a place in spatial planning and aiding managers in developing dialogue with other stakeholders. A case study of their application is provided.

Maternal and neonatal factors and mortality in children with Down syndrome born in 1973-1980 and 1995-1998.

AIMS: To investigate maternal and neonatal factors in Down syndrome (DS) at birth, the impact of a congenital heart defect (CHD) on these factors and changes over time. METHODS: Medical data of children with DS born in northern Sweden in the periods 1973-1980 (n = 219) and 1995-1998 (n = 88) obtained from the Swedish Medical Birth Register were compared. A comparison with the general population on a group level was also made. RESULTS: The main finding was a reduction in infant mortality in DS, from 14.2% to 2.3% in 1995-1998 (p < 0.001), but this was still significantly higher than in the general population. The rate of Caesarean sections increased over time (from 14.5% to 27.3%, p < 0.05) even after adjustment for increased maternal age. No change over time was detected in the following rates: premature birth (gestational age < or = 36) (25%); asphyxia (5-min Apgar score < or = 6) (8%); low birthweight (< 2500 g) (14%); or small for gestational age (SGA) (14%); all rates were significantly higher than those of the general population. A CHD did not seem to influence the rates of these factors in a logistic regression model. CONCLUSION: Infant mortality decreased substantially over time in the DS group, whereas there was no reduction in the rate of asphyxia, SGA, low birthweight or prematurity. The presence of a CHD did not influence any of the neonatal factors studied.

Utilization of medical care among children with Down's syndrome.

BACKGROUND: The present authors have previously found an increased mortality rate in children with Down's syndrome (DS) and a congenital heart defect (CHD). The aim of the present study was to investigate the utilization of medical care in relation to congenital malformations in DS. METHOD: Retrospectively, 211 children with DS born between 1973 and 1980 in the northern part of Sweden were followed up for at least 17 years (1973-1997). The duration of neonatal care was compared with that of children with DS born between 1995 and 1998 in the same region. RESULTS: Neonatal care was reduced over time. Almost 50% of the children had CHD, and before 10 years of age, these subjects were admitted for inpatient care twice as often as children with DS who did not have malformations, and had more than 12 times as many inpatient days per month. The existence of a gastrointestinal or other malformation increased inpatient days per month four and two times, respectively, compared to healthy children with DS. During the first 10 years of life, children with DS and a CHD accounted for 71% of all inpatient days caused by infections. No gender differences were observed. CONCLUSIONS: At a group level, the presence of a CHD was the most important congenital abnormality in determining utilization of medical care and the burden of infections in the population of children with DS.

Mortality in Down's syndrome in relation to congenital malformations.

Down's syndrome (DS) is the most common form of intellectual disability. The syndrome is characterized by congenital malformations, especially of the heart and gastrointestinal tract, which can result in high mortality rates in the affected population. Many improvements have been made in the medical treatment of this syndrome during the past few decades and the survival of individuals with DS has increased in the industrial world. The aim of the present study was to investigate mortality in relation to congenital malformations. Medical records from all liveborn children with DS delivered between 1973 and 1980 in northern Sweden were studied, and malformations and causes of death were recorded. Out of the 219 children included in the study, a congenital heart defect was reported in 47.5% of subjects, 42.1% of whom had complete atrioventricular septal defect. Gastrointestinal tract malformations were present in 7.3% of subjects, and was frequently associated with a cardiac malformation and a very high mortality rate. Other major and minor congenital anomalies were present in 5.5% and 5.5% of subjects, respectively. In the 14.5-year follow-up of 213 children, the rate of survival was 75.6%. Mortality rates within one and 10 years after birth were 14.6% and 23.5%, respectively. Mortality within 10 years differed significantly between children with (44.1%) and without (4.5%) a congenital heart defect. A very high mortality rate was observed among children with a congenital heart defect, especially when it was combined with a gastrointestinal malformation.

Repair of complete atrioventricular canal. 15 year's experience.

Corrective surgery for complete atrioventricular canal was performed over a 15-year period on 72 patients, 49 of whom had Down's syndrome: 46 were without major associated cardiac anomalies and 15 had previously undergone pulmonary artery banding. The pressures in the right and left ventricles equilibrated in 77% of the patients. The early mortality rate was 18% and the late mortality 7%. At follow-up 4% of the patients had severe mitral incompetence and 6% had severe tricuspid incompetence. The mean reduction of pulmonary artery pressure was 40 mmHg. The mean peak systolic pressure ratio between pulmonary artery and aorta was 0.73 before repair and had fallen to 0.38 at follow-up catheterization, when 88% of the patients were asymptomatic. Early repair in the first year of life is nowadays preferred in order to avoid progressive pulmonary vascular disease. Although the alternative of first-stage pulmonary artery banding gave lower (13%) mortality at the corrective operation, it cannot be recommended if atrioventricular valvular incompetence is significant.

Myocarditis in children with inflammatory bowel disease.

Inflammatory bowel disease (IBD) in children and adults is often associated with extracolonic manifestations in other organs, such as the joints, skin, and liver. Cardiac manifestations are considered to be very rare; in a recent survey of the literature we found only 23 cases, most of them in adults. Several extensive reviews and standard textbooks of IBD do not even mention perimyocarditis as a complication. During the past 10 years we have treated 106 patients with IBD in the Department of Pediatrics at St. Göran's Children's Hospital. Of these patients, two adolescent boys developed myocarditis as an extracolonic manifestation. In reporting these two cases, we wish to point out that cardiac involvement occurs in children and we also wish to show that the prognosis is usually good. Another interesting feature was that both of these boys developed myocarditis at a time when one of them had only minor gastrointestinal symptoms and the other had not yet been diagnosed as having IBD.