Cultured amniotic fluid cells for prenatal diagnosis of lysosomal storage disorders: A methodological study

The influence of culture conditions on the ultrastructure and enzyme activities of amniotic fluid cells are reported. Morphological changes were determined as a function of the number of lysosomal-like inclusion bodies per cell, and these results correlated to the activity of Thiexosaminidase, a-mannosidase, β-glucuronidase, arylsulphatase C and 5′ nucleotidase. The parameters examined were pH of the culture media, type of media, increasing cell passage and day of harvest. Our results indicate that enzyme activities are less sensitive to changes in culture conditions as compared to ultrastructural changes. We therefore recommend that in order to obtain reliable ultrastructural results for the diagnosis of storage disorders, cultures should be grown in MEM as the culture medium, the pH of the medium carefully monitored to remain below pH 7·4, examining the cultures no later than the eighth cell passage and no later than the 10th day after subculture.     

Uncertainties of internal dose assessment for animals and plants due to non-homogeneously distributed radionuclides

The dose conversion coefficients (DCCs) for the assessment of internal absorbed dose rate in reference animals and plants have been generally calculated assuming a homogeneous distribution of radionuclides within the body. Realistic scenarios of internal exposure must account for some radionuclides which tend to concentrate in specific organs or tissues. To study the effect of such inhomogeneous distributions, internal DCCs have been calculated assuming both a central and an eccentric point source. The analysis of the results showed that uncertainties of the whole body DCC due to non-homogeneous radionuclide distribution are less than 30% for photons and electrons for all considered organisms. For electrons, the uncertainties are negligible below certain energies, dependent on the size of the organisms. Additionally, the organ doses due to the accumulation of the radionuclide in an organ are also described and organ/whole body doses ratios are estimated.     

Transport modes and pathways of the strongly sorbing pesticides glyphosate and pendimethalin through structured drained soils

Leaching of the strongly sorbing pesticides glyphosate and pendimethalin was evaluated in an 8-month field study focussing on preferential flow and particle-facilitated transport, both of which may enhance the leaching of such pesticides in structured soils. Glyphosate mainly sorbs to mineral sorption sites, while pendimethalin mainly sorbs to organic sorption sites. The two pesticides were applied in equal dosage to a structured, tile-drained soil, and the concentration of the pesticides was then measured in drainage water sampled flow-proportionally.The leaching pattern of glyphosate resembled that of pendimethalin, suggesting that the leaching potential of pesticides sorbed to either the inorganic or organic soil fractions is high in structured soils. Both glyphosate and pendimethalin leached from the root zone, with the average concentration in the drainage water being 3.5 and 2.7 μg L⁻¹, respectively. Particle-facilitated transport (particles >0.24 μm) accounted for only a small proportion of the observed leaching (13-16% for glyphosate and 16-31% for pendimethalin). Drain-connected macropores located above or in the vicinity of the drains facilitated very rapid transport of pesticide to the drains. That the concentration of glyphosate and pendimethalin in the drainage water remained high (>0.1 μg L⁻¹) for up to 7 d after a precipitation event indicates that macropores between the drains connected to underlying fractures were able to transport strongly sorbing pesticides in the dissolved phase. Lateral transport of dissolved pesticide via such discontinuities implies that strongly sorbing pesticides such as glyphosate and pendimethalin could potentially be present in high concentrations (>0.1 μg L⁻¹) in both water originating from the drainage system and the shallow groundwater located at the depth of the drainage system.     

Long-term recovery narratives following major disasters in Southeast Asia

Regional Environmental Change - Most studies of major disasters focus on the impacts of the event and the short-term responses. Some evaluate the underlying causes of vulnerability, but few...     

Effects of chronic exposure to radiofrequency electromagnetic fields on energy balance in developing rats

The effects of radiofrequency electromagnetic fields (RF-EMF) on the control of body energy balance in developing organisms have not been studied, despite the involvement of energy status in vital physiological functions. We examined the effects of chronic RF-EMF exposure (900 MHz, 1 V?m^?1) on the main functions involved in body energy homeostasis (feeding behaviour, sleep and thermoregulatory processes). Thirteen juvenile male Wistar rats were exposed to continuous RF-EMF for 5 weeks at 24 °C of air temperature (T _a) and compared with 11 non-exposed animals. Hence, at the beginning of the 6th week of exposure, the functions were recorded at T _a of 24 °C and then at 31 °C. We showed that the frequency of rapid eye movement sleep episodes was greater in the RF-EMF-exposed group, independently of T _a (+42.1 % at 24 °C and +31.6 % at 31 °C). The other effects of RF-EMF exposure on several sleep parameters were dependent on T _a. At 31 °C, RF-EMF-exposed animals had a significantly lower subcutaneous tail temperature (?1.21 °C) than controls at all sleep stages; this suggested peripheral vasoconstriction, which was confirmed in an experiment with the vasodilatator prazosin. Exposure to RF-EMF also increased daytime food intake (+0.22 g?h^?1). Most of the observed effects of RF-EMF exposure were dependent on T _a. Exposure to RF-EMF appears to modify the functioning of vasomotor tone by acting peripherally through α-adrenoceptors. The elicited vasoconstriction may restrict body cooling, whereas energy intake increases. Our results show that RF-EMF exposure can induce energy-saving processes without strongly disturbing the overall sleep pattern.     

Health and Welfare in Danish Dairy Cattle in the Transition to Organic Production: Problems, Priorities and Perspectives

During the past few years,organic dairy farming has grown dramatically inDenmark. Consequently, an increasing number ofpeople are encountering this method ofproduction for the first time. Amongst these,many veterinarians have suddenly had to dealwith organic herds in their home district, and,meeting examples of poor animal welfare, theyhave recently started to express some concerns.Against this background, a so-called``Synthesis of Knowledge' project was initiatedto examine the health and welfare of dairycattle and the use of medication in thetransition to organic production. The aim ofthe project was to investigate associatedproblems from the point of view of the dairyherd. Based on qualitative research interviewswith vets and agricultural advisors, as well asfocus group interviews with farmers who hadrecently converted from conventional to organicfarming, an expert panel attempted to identifyproblem areas and possible solutions. Theproblems related to (a) the adjustment to newand unknown practices, (b) poor management ingeneral, and (c) inappropriate legislation fororganic farming.One problem area was the rearing of dairycalves, particularly with regard to theestablishment of post partumrelationships between cow and calf, grouphousing, and the grazing of young animals. A``natural life' was identified as beingfundamental to organic animal husbandry. Interms of animal welfare, this concept can beunderstood as a way of living in which the calfis allowed to express its natural behavior andsatisfy its natural needs. Essentially, theconditions needed for good calf welfare requirethe compatibility and interplay of elementsfrom ``nature' (the natural life; includingopportunities to satisfy natural needs) and``culture' (farmer management skills; exerciseof care). These elements should be balanced toensure animal welfare in organic herds.     

Opportunities for better use of collective action theory in research and governance for invasive species management

Controlling invasive species presents a public-good dilemma. Although environmental, social, and economic benefits of control accrue to society, costs are borne by only a few individuals and organizations. For decades, policy makers have used incentives and sanctions to encourage or coerce individual actors to contribute to the public good, with limited success. Diverse, subnational efforts to collectively manage invasive plants, insects, and animals provide effective alternatives to traditional command-and-control approaches. Despite this work, there has been little systematic evaluation of collective efforts to determine whether there are consistent principles underpinning success. We reviewed 32 studies to identify the extent to which collective-action theories from related agricultural and environmental fields explain collaborative invasive species management approaches; describe and differentiate emergent invasive species collective-action efforts; and provide guidance on how to enable more collaborative approaches to invasive species management. We identified 4 types of collective action aimed at invasive species—externally led, community led, comanaged, and organizational coalitions—that provide blueprints for future invasive species management. Existing collective-action theories could explain the importance attributed to developing shared knowledge of the social-ecological system and the need for social capital. Yet, collection action on invasive species requires different types of monitoring, sanctions, and boundary definitions. We argue that future government policies can benefit from establishing flexible boundaries that encourage social learning and enable colocated individuals and organizations to identify common goals, pool resources, and coordinate efforts.     

Variation of Solar Attenuation with Height over an Urbanized Area

The information presented in this paper is directed to environmental scientists who are concerned about the quality of air over an urban area. Specifically, the purpose of this study is to show quantitatively the magnitude of solar attenuation for individual air layers in the lowest 1000 m of an urban atmosphere. This reveals dramatically the diverse variation of mass concentration with height. The information is useful in urban planning, in site selection, and in air quality control.

The data were gathered on different roof top levels and on helicopter flights using modified Volz sun photometers, psychrometers, hot-wire anemometers, and an electric thermometer. The results show that, for instance, on a "polluted" day the lowest 1000 m of air attenuate about 65% of the solar beam, whereas on a “clean” day the contribution to the total solar attenuation is still 30%. Shallow air layer increments of 45 m near the ground were found to contribute up to 21% to the total solar attenuation. Aerosols form the dominant attenuation component in polluted air layers near the ground, whereas the extinction due to air molecules becomes dominant in higher and relatively cleaner atmospheric air layers.

Significance tests show that turbidity variations with height over widely spaced locations are relatively homogeneous. This may indicate a rather uniform spread of the urban dust dome over the neighboring countryside. No significant change in the vertical turbidity structure was found between data collected in 1961–62 and 1969.

For an effective control of the ambient air quality, conclusive information on the lateral and vertical spread of pollution is necessary. Turbidimetric studies based on scattering theory can economically supply this information.