Influence of extracellular matrix on the proliferation of human amniotic fluid cells in vitro

Factors which influence the proliferation of human amniotic fluid cells in vitro have potential importance in reducing the time for prenatal diagnosis. Fibroblast growth factor (FGF) has been shown to be mitogenic for human amniotic fluid cells. The observation that cells which respond to FGF in vitro produce their own extracellular matrix (ECM), led to the use of an ECM as a substrate to assess proliferation. Pooled amniotic fluid cells maintained on an ECM prepared from bovine corneal endothelial cells demonstrated a significant increase in proliferation when compared with cells maintained on plastic substrate in the presence or absence of FGF. If FGF was added to cultures of amniotic fluid cells maintained on ECM, further increases in proliferation were noted compared with cells maintained on ECM in the absence of FGF. These results indicate that the substrate upon which amniotic fluid cells are maintained can have a profound influence on their proliferation.     

Prospects for improved hurricane protection on oceanic islands: Hawaii after Hurricane Iwa *

Hurricane Iwa (23rd November 1982) produced Hawaii's costliest natural disaster and revealed serious flaws in the area's hurricane preparedness, response and mitigation programs. Twenty-eight months later, a follow-up study showed that impacted communities and facilities had been reconstructed with only selective and limited attention to mitigating future coastal storm hazards. Prospects for the reduction of hazard vulnerability on oceanic islands through post-disaster mitigation measures are assessed in the light of Hawaii's experience.     

Mineral Soil and Solution Responses to Experimental N and S Enrichment at the Bear Brook Watershed in Maine (BBWM)

Buried mineral soil-bags and natural solutions were studied as indicators of forest ecosystem response to elevated N and S inputs at the Bear Brook Watershed in Maine (BBWM). The BBWM is the site of a paired watershed manipulation experiment in a northern New England forested ecosystem. The study includes two small (10 ha each) catchments dominated by northern hardwood forests with red spruce in the upper elevations. Treatments consist of (NH4)2SO4 applied to the West Bear watershed six times per year, increasing N and S deposition 3× and 2× above ambient values, respectively. Buried mineral soil-bag changes over time reflected both the native soil environment and the treatments. Most of the treatment effects on mineral soils were evident as higher inorganic S found in the treated watershed soils. Adsorbed SO4 in the buried mineral soil-bags increased by approximately 40% under softwood stands and 50% under hardwood stands over the study period. Hardwood soil solutions responded with significant increases in NO3 and SO4 concentrations that resulted in accelerated cation leaching, primarily Ca and Al. Few differences that could be attributed to treatments were evident in soil solutions under softwoods. No treatment effects were evident in throughfall and stemflow chemistry.     

Arrested municipal solid waste incinerator fly ash as a source of heavy metals to the UK environment

Arrested fly ash samples from most currently operating municipal solid waste (MSW) incinerators in the UK have been analysed for a range of elements. Some of the more important heavy metals ranged in concentration as follows: Cd, 21-4646 (median = 271) mg kg(-1); Cu, 296-1307 (642) mg kg(-1); Cr, 44-1328 (574) mg kg(-1); Ni, 45-2204 (74) mg kg(-1); Pb, 447-9704 (4337) mg kg(-1); and Zn, 2285-13,500 (9232) mg kg(-1). These concentrations represent considerable enrichments relative to median UK soil concentrations. Enrichment ratios (defined as median fly ash: median UK soil) were as follows: Mn 1.6; Co 2.6; Ni 3.3; Ba 11; Sr 11; Cr 15; Cu 35; Pb 108; Zn 113; Cd 387. It is estimated that MSW incinerator ash contributes c. 15 t Cd and 241 t Pb to UK landfill sites per annum. These figures compare with previous studies by Hutton & Symon (Hutton, M. & Symon, C. (1986). The quantities of cadmium, lead, mercury and arsenic entering the UK environment from human activities. Sci. Total Environ., 57, 129-50.) which estimated that annual inputs to UK landfills from coal fly ash are c. 60 t Cd and 1270 t Pb. However, it is argued that metals associated with MSW ashes are potentially of greater environmental significance than in coal ashes, because they are much more available and present at much higher concentrations.     

Photodechlorination of methoxychlor induced by hydroquinone: Rearrangement and conjugate formation

Reductive degradation of the pesticide methoxychlor by photolysis in the presence of hydroquinone in dilute solutions of acetonitrile or 1:1 aqueous t-butanol leads to processes other than simple dechlorination. Direct radical coupling with hydroquinone forms a markedly estrogenic conjugate. A pH dependant molecular rearrangement gives pro-estrogenic 4,4′-dimethoxy-α,α′-dichlorostilbenes, and condensation with hydroquinone yields the chlorine free polycyclic aromatic, 12-hydroxy-3,6-dimethoxybenzo[b]phenanthro[9,10-d]furan.     

Field validation of sound mitigation models and air pollutant emission testing in support of missile motor disposal activities

The U.S. Department of Defense approved activities conducted at the Utah Test and Training Range (UTTR) include both operational readiness test firing of intercontinental ballistic missile motors as well as the destruction of obsolete or otherwise unusable intercontinental ballistic missile motors through open burn/open detonation (OB/ OD). Within the Utah Division of Air Quality, these activities have been identified as having the potential to generate unacceptable noise levels, as well as significant amounts of hazardous air pollutants. Hill Air Force Base, UT, has completed a series of field tests at the UTTR in which sound-monitoring surveillance of OB/OD activities was conducted to validate the Sound Intensity Prediction System (SIPS) model. Using results generated by the SIPS model to support the decision to detonate, the UTTR successfully disposed of missile motors having an aggregate net explosive weight (NEW) of 56,500 lbs without generating adverse noise levels within populated areas. These results suggest that, under appropriate conditions, missile motors of even larger NEW may be detonated without exceeding regulatory noise limits. In conjunction with collecting noise monitoring data, air quality data was collected to support the development of air emission factors for both static missile motor firings and OB/OD activities. Through the installation of 15 ground-based air samplers, the generation of combustion fixed gases, hazardous air pollutants, and chlorides were monitored during the 56,500-lb NEW detonation event. Comparison of field measurements to predictions generated from the U.S. Navy's energetic combustion pollutant formation model, POLU4WN, indicated that, as the detonation fireball expanded from ground zero, organic compounds as well as carbon monoxide continued to oxidize as the hot gases reacted with ambient air. Hazardous air pollutant analysis of air samplers confirmed the presence of chloromethane, benzene, toluene, 1,2-propadiene, and 2-methyl-l-propene, whereas the absence of hydrogen chloride gas suggested that free chlorine is not generated during the combustion process.     

Investigation of geothermal energy utilization for thermal regulation of aquaculture raceway

ABSTRACT

Aquaculture raceway temperature has a direct impact on the aquatic specie being reared. In regions that undergo significant seasonal temperature variations, the thermal management of the raceway temperature becomes a challenge, directly impacting the production yield. This study investigates a novel approach to regulate the raceway temperature in a sustainable way by utilizing geothermal energy. A numerical energy model was developed to simulate heat transfer in a geothermal system encompassing both the individual borehole heat exchangers and their thermal interactions. Simulations were conducted for different configurations of the geothermal system over a complete seasonal cycle. Results show that flow rate, number of boreholes and the borehole spacing influence the temperature of the fluid at the raceway inlet. An increase in the number of boreholes provided better thermal regulation but an increase in the flow rate through the boreholes provided less thermal regulation. A borehole spacing of 6 m was found to be appropriate to reduce thermal interference. It was also observed that an increase in the fraction of the fluid passed through the geothermal system enhances the overall thermal regulation, with higher thermal regulation at lower flow rates. Results show that when 100% of the fluid passed through a 64 boreholes geothermal system, the average regulated raceway inlet temperature was 23% higher in winter months and 16% lower in summer months at the flow rate of 21.5 L/s compared to than at 43 L/s.     

Integrating total cost assessment with new management practices and mandates

Today's environmental manager cannot afford to operate in a vaccum, but continually adjusts to the latest management initiatives, whether it is Activity Based Costing, ISO 14000, or Total Quality Management. These paradigms offer an excellent structure to view process improvements and implement changes, however, they all tend to miss the mark in one critical area—quantifying and tracking the true cost of environmental management. The recent upsurge of interest in Total Cost Assessment (TCA) is proof positive that, although many excellent management programs exist, something is still missing. In this article, the author shows how using TCA in conjunction with these practices enhances their effectiveness and shows the total picture of environmental management costs.     

Ontogeny of fetal liver glucose-6-phosphatase activity

A reliable and sensitive microassay for the measurement of liver glucose-6-phosphatase is described. Human fetal liver was assayed for glucose-6-phosphatase activity from 7.5 to 24 weeks of gestation and was found to have a mean activity of 2.11 nmol per min per mg of protein. This was approximately 30 per cent of the postnatal controls assayed by the same method, but there was no evidence of a change in activity during the gestational period examined. If fetal liver tissue can be reliably obtained, it may be possible to determine a deficiency of glucose-6-phosphatase in fetuses who are at risk.     

First-trimester maternal serum unconjugated oestriol and alpha-fetoprotein in fetal Down's syndrome

Maternal sera (MS) taken from 1396 women prior to chorionic villus sampling at 9–12 menstrual weeks were assayed for unconjugated oestriol (uE3) and alpha-fetoprotein (AFP). Median levels increased by 41 and 26 per cent per week respectively in normal pregnancies. There were 32 pregnancies with a chromosome abnormality. The median MS uE3 and AFP were 0.73 and 0.75 multiples of the median (MoM) respectively in the ten cases of Down's syndrome (DS) but not decreased in the other abnormalities. These results suggest that both uE3 and AFP may be useful in identifying DS in the first trimester. Additional prospective studies are needed to confirm these findings.