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To analyze complex and noncomplex cardiac malformations regarding prevalence and in relation to demographic variables, we pooled data on infants (age 1 year or younger) with congenital cardiovascular defects from three large birth defect registries in California, Sweden, and France. Altogether, 12,932 infants had one or more congenital heart defects out of 4.4 million live births and stillbirths. The registries in Sweden and France obtained data through reporting from various sources; in California, medical records were reviewed. As expected, definitions and ascertained conditions differed among each of the registries. The total rates for severe defects were similar (1.43 per 1,000), but differed for specific defects. Clear differences in epidemiological characteristics existed for specific defects; for example, severe cardiac defects sex ratios were significantly high for hypoplastic left heart syndrome, d-transposition of great vessels, double outlet right ventricle, total anoralous pulmonary venous return, tetralogy of Fallot, and significantly low for pulmonary atresia without ventricular septal defect and endocardial cushion defect. Few defects were similar for several epidemiological characteristics, but, for example, the combination of ventricular and atrial septal defects appeared equivalent with endocardial cushion defect under some circumstances, yet behaved differently with regard to associated noncardiovascular defects.

There were three objectives of this study: to investigate possible specificity in the association between specific cardiac defects and chromosomal anomalies; to evaluate ways of categorizing cardiac defects into larger groups with epidemiological similarities that could indicate similarities in etiology or pathogenesis; and to analyze the relationship between specific cardiac defects and diabetes. We pooled data on infants (aged 1 year or younger) with congenital cardiovascular defects from three large birth defect registries in California, Sweden, and France. The registries in Sweden and France obtained data through reporting from various sources; in California, medical records were reviewed. For severe congenital heart defects, the percentage of infants with identified chromosomal anomalies varied between 0.9% for d-TGV to 68.4% for ECD. In general, specific cardiac conditions have different risk factors. For example, conotruncal defects have been traditionally grouped, but the data presented in this paper indicates more differences for risk factors for the components of conotruncal defects: tetralogy of Fallot, d-TGV, common truncus, and DORV. In general, we suggest the strategy of \"splitting\" rather than \"lumping\" when searching for specific genetic factors and/or teratogens. Adequate analysis thus requires large registries or collaboration among registries. The findings did not support constellations between mothers' diabetes and specific defects.

Soils are fundamental to terrestrial ecosystem functioning and food security, thus their resilience to disturbances is critical. Furthermore, they provide effective models of complex natural systems to explore resilience concepts over experimentally-tractable short timescales. We studied soils derived from experimental plots with different land-use histories of long-term grass, arable and fallow to determine whether regimes of extreme drying and re-wetting would tip the systems into alternative stable states, contingent on their historical management. Prior to disturbance, grass and arable soils produced similar respiration responses when processing an introduced complex carbon substrate. A distinct respiration response from fallow soil here indicated a different prior functional state. Initial dry:wet disturbances reduced the respiration in all soils, suggesting that the microbial community was perturbed such that its function was impaired. After 12 drying and rewetting cycles, despite the extreme disturbance regime, soil from the grass plots, and those that had recently been grass, adapted and returned to their prior functional state. Arable soils were less resilient and shifted towards a functional state more similar to that of the fallow soil. Hence repeated stresses can apparently induce persistent shifts in functional states in soils, which are influenced by management history.

Soils are fundamental to terrestrial ecosystem functioning and food security, thus their resilience to disturbances is critical. Furthermore, they provide effective models of complex natural systems to explore resilience concepts over experimentally-tractable short timescales. We studied soils derived from experimental plots with different land-use histories of long-term grass, arable and fallow to determine whether regimes of extreme drying and re-wetting would tip the systems into alternative stable states, contingent on their historical management. Prior to disturbance, grass and arable soils produced similar respiration responses when processing an introduced complex carbon substrate. A distinct respiration response from fallow soil here indicated a different prior functional state. Initial dry:wet disturbances reduced the respiration in all soils, suggesting that the microbial community was perturbed such that its function was impaired. After 12 drying and rewetting cycles, despite the extreme disturbance regime, soil from the grass plots, and those that had recently been grass, adapted and returned to their prior functional state. Arable soils were less resilient and shifted towards a functional state more similar to that of the fallow soil. Hence repeated stresses can apparently induce persistent shifts in functional states in soils, which are influenced by management history.

Around half a million tonnes of biosolids (sewage sludge dry solids) are applied to agricultural land in the United Kingdom each year, and this may increase to 732000 t by 2005/6. The heavy metals contained in biosolids may permanently degrade the microbial decomposer communities of agricultural soils. We used amplified ribosomal DNA restriction analysis of the extractable bacterial fraction to compare the diversity of a zinc-contaminated soil (400 mg kg-1 Zn; pH 5.7 and 1.36% Corg) with that of a control soil (57 mg kg-1 Zn; pH 6.2 and 1.40% Corg) from a long-term sewage sludge experiment established in 1982 at ADAS Gleadthorpe. Comparison of the restriction fragment length polymorphisms of 236 clones from each soil suggested that the stress caused by zinc toxicity had lowered bacterial diversity. There were 120 operational taxonomic units (OTUs) in the control soil, but only 90 in the treated soil, a decrease of 25%. While the control soil had 82 single-occurrence OTUs the contaminated soil had only 52. The fall in diversity was accompanied by a decrease in evenness. The most abundant OTUs in the contaminated soil (which tended to be common to both soils) accounted for a higher proportion of clones than in the control. The most dominant OTU, in both soils, belonged to the Rubrobacter radiotolerans group of the high G+C Gram-positive bacteria. The data was also used to develop efficient sampling strategies.

Deliberate exposure to medical ionising radiation should be as low as reasonably practicable but the reduction of radiation from CT should be balanced against diagnostic image quality. The ability of ultra-low-dose CT (uLDCT: similar radiation to chest X-ray) to demonstrate low contrast abnormalities (emphysema and interstitial lung abnormality (ILA)) is unclear.The aim of this cross-sectional study was to analyse the lung parenchymal findings from uLDCT scans against physiological measures of respiratory function. WA Asbestos Review Programme participants were eligible if they had an uLDCT scan and lung function assessment between Janary and December 2018. All scans were performed using a single CT machine and reported using a standardised, semiquantitative synoptic report which includes emphysema and linear fibrosis (ILA) scores. Of 1344 participants, median (IQR) age was 72.0 (65.0-78.0) years, the majority were males (84.9%) with mixed occupational asbestos exposure (68.1%). There were 721 (53.6%) with no abnormality, 158 (11.8%) with emphysema, 465 (34.6%) with ILA. Mean radiation dose was 0.12 mSv. There was statistically significant between group differences for all physiological parameters of lung function compared with controls. For instance, the emphysema score significantly correlated with obstructive forced expiratory volume in 1 s (FEV )/forced vital capacity ratio (r=0.512), per cent predicted FEV (r=0.24) and lower diffusion of carbon monoxide (DLCO) (r=0.337). Multivariate modelling demonstrated that increasing age, emphysema and fibrosis scores predicted reduced DLCO (adjusted R =0.30). uLDCT-detected parenchymal lung abnormalities correlate strongly with significant changes on lung function testing suggesting the observed CT abnormalities are of physiological and clinical significance.

At the planning or screening level of urban development, analytical modeling using derived probability distribution theory is a viable alternative to continuous simulation, offering considerably less computational effort. A new set of analytical probabilistic models is developed for predicting the erosion potential of urban stormwater runoff. The marginal probability distributions for the duration of a hydrograph in which the critical channel velocity is exceeded (termed exceedance duration) are computed using derived probability distribution theory. Exceedance duration and peak channel velocity are two random variables upon which erosion potential is functionally dependent. Reasonable agreement exists between the derived marginal probability distributions for exceedance duration and continuous EPA Stormwater Management Model (SWMM) simulations at more common return periods. It is these events of lower magnitude and higher frequency that are the most significant to erosion-potential prediction. Key words: erosion, stormwater management, derived probability distribution, exceedance duration.

Water-model experiments were carried out on 1:14-scale models of venturi, distributor, and jet-flow burners to ascertain flow patterns at varying Reynolds numbers (60 000-507 000) using time-lapse streak photography and video streak photography. Digital particle image velocimetry (DPIV) was used to determine the axial and radial velocities and to estimate the turbulence kinetic-energy field beneath the distributor burner. In the DPIV experiments, a temporal instability in the main jet exiting from the burner occurred at a Reynolds number=104 000, a Strouhal number approx3x10 exp -3 , and a large expansion ratio (shaft /burner-diameter ratio=10). The main jet usually pointed away from the burner inlet but was also observed to fluctuate and precess in a quasi-random fashion. Recommendations are made for improving flash-smelting burner performance by promoting conditions to eliminate precessing. The use of higher Reynolds numbers was recommended to improve both the use of shaft volume and the mixing of the concentrate particles and as stream. A three-dimensional (3-D) mathematical model was used to simulate the water flow through the distributor burner, shaft, and settler. The predicted velocity field consisted of a main jet pointing away from the burner inlet and a large recirculation zone in the center of the shaft. The predicted and measured velocity magnitudes compared well in the recirculation zone, but the steady-state mathematical model predicted higher velocity values in the main jet than were experimentally determined.

Residents of a census tract that received drinking water from a well contaminated with solvents were previously shown to experience a spontaneous abortion rate over twice that occurring in an unexposed census tract. In addition, the rate of birth defects in the exposed tract was three times that in the unexposed tract. Surprisingly, increased tapwater consumption was associated with higher rates of spontaneous abortions in both the exposed and the unexposed tracts. Subsequent studies in this area have investigated the relation between spontaneous abortions and consumption of tapwater in more detail. In this report, data from the original study have been re-analyzed using methods comparable with those used in more recent studies. These results confirm the association between spontaneous abortions and reported cold tapwater consumption that was seen in the original study. The observed effect was not due to maternal risk factors, nor was it a function of consumption of bottled water. After controlling for bottled water, the odds ratio for consumption of tapwater was 3.4 (95% confidence interval = 0.6-19.4).

This case-control study, conducted in a California county that had a local incident of water contamination in 1981, investigated the relation between a mother's reported consumption of tap water during pregnancy and congenital cardiac anomalies in their offspring born during 1981–1983. Data were obtained from telephone interviews with 145 mothers of children born with a severe cardiac anomaly and 176 mothers of children born without such an anomaly. A positive association between a mother's consumption of home tap water during the first trimester of pregnancy and cardiac anomalies in her infant was unrelated to the incident of water contamination, the mother's race, or her educational level. A negative relation was found between a mother's use of bottled water and cardiac anomalies among the infants. These findings corresponded primarily to births in 1981. These data could not fully distinguish between a potential causal agent in the water and differential reporting of exposure by study subjects.