Trisomy 16 fetus surviving into the second trimester

A 27-year-old gravida 4, para 3 was found to have anhydramnios at 14 weeks' gestation following a size/date discrepancy noted at her routine prenatal visit. A detailed ultrasound revealed multiple fetal anomalies including congenital heart defect, chest hypoplasia, and bilateral dysplastic kidneys. Karyotype revealed trisomy 16 in 15/15 cells from a tissue specimen obtained from the fetal cord insertion site following elective pregnancy termination.     

Effects of silver and cerium dioxide micro- and nano-sized particles on Daphnia magna

Acute (96 h) and chronic (21 d) exposures of Daphnia magna neonates were carried out with nano- and micro-sized Ag and CeO(2) particles to assess the influence of both material and size of particles on mortality and moulting. Mortality rates for silver in the acute exposures were: AgNP, 56.7 ± 23.3% at 0.1 mg L(-1) and 100 ± 20% at 1 mg L(-1), and micro-Ag, 13.3 ± 6.7% at 0.1 mg L(-1) and 80 ± 20% at 1 mg L(-1). CeO(2) was not acutely toxic at concentrations up to 10 mg L(-1). Mortality for Ag over 21d at concentrations of up to 0.05 mg L(-1) was low, while mortality of 30% was observed for 0.001 mg L(-1) of nano-Ag. CeO(2), with the exception of the 10 mg L(-1) of nano-CeO(2) (100% mortality by day 7), was non-toxic. Inhibition of moulting and growth in the acute study occurred at toxic concentrations (Ag particles), and at 10 mg L(-1) of nano-CeO(2). The chronic study revealed reduced moulting at 0.001 mg L(-1) of nano-Ag and 0.01 and 0.05 mg L(-1) of both sizes of Ag, but there was no impact on D. magna size, and no effects of CeO(2). The toxicity of nano-CeO(2) may be attributed to reduced feeding and physical interference with the daphnids' carapace, resulting in reduced swimming ability. Our results suggest that Ag NPs in particular have the potential to be harmful to aquatic invertebrates after release into the environment, whereas CeO(2) particles appear to cause little adverse effects, and only at environmentally irrelevant concentrations.     

Long-Term Landscape Change and Bird Abundance in Amazonian Rainforest Fragments

Abstract:  The rainforests of the Amazon basin are being cut by humans at a rate >20,000 km²/year, leading to smaller and more isolated patches of forest, with remaining fragments often in the range of 1–100 ha. We analyzed samples of understory birds collected over 20 years from a standardized mist-netting program in 1– to 100-ha rainforest fragments in a dynamic Amazonian landscape near Manaus, Brazil. Across bird guilds, the condition of second growth immediately surrounding fragments was often as important as fragment size or local forest cover in explaining variation in abundance. Some fragments surrounded by 100 m of open pasture showed reductions in insectivorous bird abundance of over 95%, even in landscapes dominated by continuous forest and old second growth. These extreme reductions may be typical throughout Amazonia in small (≤10 ha), isolated fragments of rainforest. Abundance for some guilds returned to preisolation levels in 10- and 100-ha fragments connected to continuous forest by 20-year-old second growth. Our results show that the consequences of Amazonian forest loss cannot be accurately described without explicit consideration of vegetation dynamics in matrix habitat. Any dichotomous classification of the landscape into "forest" and "nonforest" misses essential information about the matrix.     

Preliminary indications from atomic force microscopy of the presence of rapidly-formed nanoscale films on aquifer material surfaces

The objective of this study was to determine if there is a nanoscale surface film on aquifer-like materials exposed to deep groundwaters, as has previously been found on surfaces exposed to surface and soil waters. Such surface films will modify surface properties that are so important in determining the mobility of many groundwater pollutants. Muscovite mica was used because a) it is a good analogue for the main sorbing phases of many clastic aquifers and b) its cleavage planes are atomically flat allowing high resolution imaging. Freshly-cleaved muscovite plates were exposed to groundwater from a sandstone aquifer for 30 min, and surface properties (morphology, coverage, roughness and tip–substrate force interactions) were measured using atomic force microscopy (AFM). A patchy surface film of several nanometres in depth, incorporating larger separate particles, was found on the mica surface. This film was associated with significantly increased roughness values and AFM probe–sample interaction forces compared with pure water and inorganic (synthetic groundwater) solution controls. Although the results reported are preliminary in nature, if confirmed, such films are likely to affect sorption reactions, surface-facilitated redox interactions, non-aqueous phase liquid wetting angles, and colloid–pathogen–rock attachment, and will thus be of importance in understanding natural attenuation and migration of dissolved, non-aqueous and particulate phases in groundwaters.     

Fluorescence characterization of cross flow ultrafiltration derived freshwater colloidal and dissolved organic matter

3-D fluorescence excitation-emission matrix (EEM) spectrophotometry was applied to investigate the fluorescence characterization of colloidal organic matter (COM) and truly dissolved organic matter (DOM) from an urban lake and a rural river fractionated by the cross flow ultrafiltration (CFUF) process with a 1kDa membrane. Relatively high tryptophan-like fluorescence intensity is found in the urban water, although the fluorescence of both water samples is mainly dominated by humic/fulvic-like fluorophores. During CFUF processing, the fluorescence intensities of humic/fulvic-like materials in the retentate increased rapidly, but a slight increase is also observed in the permeate fluorescence intensity. Very different ultrafiltration behaviour occurred with respect to the tryptophan-like fluorophore, where both permeate and retentate fluorescence intensities increase substantially at the beginning of the CFUF process, then tend to remain constant at high concentration factor (cf) values. Comparison with tryptophan standards demonstrates that freshwater tryptophan-like fluorescence is not dissolved and 'free', but is, in part, colloidal and related to the ultrafiltration behaviour of fulvic/humic-like matter. A good linear relationship between the retentate humic/fulvic-like fluorescence intensity and organic carbon concentration further reveals that fluorescent humic/fulvic-like substances are the dominant contributors to colloidal organic carbon, mainly in the colloidal fraction.     

Recording the Response of Plants to Various Air Pollutants

A discussion of the methods used to determine the most economic design of chimney for a new thermal power station or large industrial plant is presented, with the objective that ground level concentration of pollutants will be kept at a minimum. Attention is paid to the geography and climatology of the site, with special reference to the frequency and height of inversions and the prevailing wind direction and speed.

A method is illustrated in using a large thermal power station as an example. The maximum sulfur dioxide concentrations at ground level are computed for several chimney heights and gas exit velocities. The values of these sulfur dioxide concentrations, the capital cost of the chimney, the pumping costs, and the gas pressures within the chimney are considered in selecting a suitable chimney height and a gas exit velocity which will meet most economically the stated objective.

The paper deals primarily with chimneys for industrial or power boiler plant of maximum continuous rating greater than 450 million Btu/hr (about 450,000 lbs of steam/hr), or to chimneys serving furnaces burning fuel at a maximum rate greater than 50,000 lbs/hr of coal, or 80,000 lbs/hr of oil. For chimneys serving plant with smaller heat inputs, chimney selection by reference to Clean Air Act 1956, Memorandum on Chimney Heights is suggested.     

New York State’s Classifications- Ambient Air Quality Objectives System

The air pollution potential of any area is directly related to its population and economic development. In New York State, this pollution potential ranges from that existing in the sparsely inhabited recreational zones to that prevailing in the densely populated and/or heavily industrialized areas. No one set of air quality standards or objectives can be developed which can reasonably be applied on a statewide basis. A classifications-air quality objectives system has been adopted by the State Air Pollution Control Board for application in New York State. In accordance with this system, specific areas can be classified in one of 16 categories. Air quality objectives, in keeping with each classification, are designed to protect health and to promote the maximum comfort and enjoyment and use of property consistent with the needs of the area concerned. The system was developed by the staff with the assistance of a council of technical advisors. Units of measurement related to the most important effect of specific contaminants are utilized. Methods of sampling and analysis are specified. The details of the classifications-objectives system, the place of the system in the state’s air resource management plan, the manner in which each segment of the state after study will be classified, and how attainment will be evaluated are described.     

Nationwide Air Pollution Control Training Efforts: Status Quo vs. Needs

This paper briefly reviews the historical development of air pollution training activities in the U. S. It describes the various types of training programs currently available, such as short courses, specialized programs, and university training at the graduate level. The level of financial support and the number of individuals enrolled in these programs are discussed. The paper concludes with an outline of future needs in terms of changes in existing training programs, extension into new areas, and the critical problem of recruitment of qualified candidates for training.