First-trimester genetic diagnosis in multiple pregnancy: Principles and potential pitfalls

Both the principles of first-trimester genetic diagnosis in multiple pregnancy and the special considerations required to avoid potential diagnostic pitfalls are presented. The experience consisted of 65 cases of twins and one case of quadruplets. Dichorionic twins were recognized by sonography in 54 cases. Transabdominal aspiration was generally preferred to trans-cervical for obtaining chorionic tissue, although in two cases both approaches were used. Diagnostic error following erroneous sampling was reported in 3 out of 54 sets of dichorionic twins (5.5 per cent). When like-sex dichorionic twins cannot be differentiated by cytogenetic or DNA polymorphism studies, amniocentesis should be recommended to confirm the reliability of the result on chorionic tissue.     

Sumo wrestling in ants: major workers fight over male production in<Emphasis Type="Italic"> Acanthomyrmex ferox</Emphasis>

In the myrmicine ant Acanthomyrmex ferox, major workers have the same number of ovarioles as queens, thrice that of minor workers, making them well suited for egg-laying. In the queen's presence, infrequent aggression allows ranking of majors but they lay only unviable trophic eggs. Major workers engage each other, but not the minors, in antennal boxing and spectacular shaking contests, a novel interaction in ants. The absence of reversals allows a clear ranking of major workers. After queen removal, aggression becomes very frequent, but previous ranking is maintained. All majors start laying reproductive eggs although they show a skew in ovary development according to ranking. The dominant major, however, actively patrols the egg-pile and cannibalises eggs laid by subordinates.     

Effects of management intensity on land snails in Swiss nutrient-poor pastures

The influence of management intensity on the richness, abundance and composition of land snail species was examined in 21 calcareous, nutrient-poor cattle pastures in the northwestern Jura mountains, Switzerland. Grazing intensity was positively correlated with the extent of fertilization of the pastures. Pastures without fertilizer application and with low grazing intensity harboured more snail species and more threatened snails than pastures with annual addition of manure or pastures with manure and nitrogen fertilizer and higher grazing intensity. Fewer snail individuals, open-land species and open-land individuals were found on pastures with high than on pastures with low management intensity. To preserve the threatened snail species in dry, nutrient-poor grasslands, a network of pastures should be managed without fertilization and grazing intensity should not exceed 180 LU ha⁻¹ d (product of livestock units per hectare and grazing days).     

Bioindication of air pollution effects near a copper smelter in Brazil using mango trees and soil microbiological properties

A field study near the copper smelter of a large industrial complex examined air pollution effects on vegetation and soil parameters in Cama?ari (northeast Brazil). Close to the smelter, soil pH-value was lower and total acidity as well as organic carbon contents were higher compared with a site far from the source and two reference sites. The acidification of top soil particularly and the drastically enhanced plant-available copper concentrations were caused by atmospheric deposition. High sulphur and copper deposition significantly reduced microbial biomass and altered functional diversity of soil microorganisms (arylsulphatase and xylanase). Large accumulations of sulphur, arsenic and copper were detected in mango leaves (Mangifera indica) growing downwind from the smelter suggesting potential food chain-mediated risk.     

Geospatial indicators of emerging water stress: an application to Africa

This study demonstrates the use of globally available Earth system science data sets for water assessment in otherwise information-poor regions of the world. Geospatial analysis at 8 km resolution shows that 64% of Africans rely on water resources that are limited and highly variable. Where available, river corridor flow is critical in augmenting local runoff, reducing impacts of climate variability, and improving access to freshwater. A significant fraction of cropland resides in Africa's driest regions, with 39% of the irrigation nonsustainable. Chronic overuse and water stress is high for 25% of the population with an additional 13% experiencing drought-related stress once each generation. Paradoxically, water stress for the vast majority of Africans typically remains low, reflecting poor water infrastructure and service, and low levels of use. Modest increases in water use could reduce constraints on economic development, pollution, and challenges to human health. Developing explicit geospatial indicators that link biogeophysical, socioeconomic, and engineering perspectives constitutes an important next step in global water assessment.     

Rhizospheric mobilization and plant uptake of radiocesium from weathered micas: II. Influence of mineral alterability

Acute K depletion in the rhizosphere can lead to increased root uptake of radiocesium. Two processes can govern this increase: the very low uptake of potassium and the weathering of Cs-fixing clay minerals. Their respective importance is, however, unknown. We investigated the effects of these processes on radiocesium mobilization by roots of willow (Salix viminalis L.) from three micas: muscovite, biotite, and phlogopite. Willows were grown in a mixed quartz-mica substrate with the three respective (134)Cs-contaminated micas as sole sources of potassium and radiocesium. After 7 wk of plant growth, the micas were partially weathered. The degree of mica weathering and the prevalent potassium concentration in the solution increased in the order muscovite (5-11 microM K) < biotite (25-32 microM K) < phlogopite (25-35 microM K). The mobilization and root uptake of radiocesium were negligible with muscovite but increased in the same order. These results show that mica weathering directly and chiefly governs the mobility of radiocesium in K-depleted rhizosphere soil. The low mobility of trace Cs in the muscovite rhizosphere is linked with the dioctahedral character of this mica, and hence to its very low alterability.     

Risk perception, risk communication, and stakeholder involvement for biosolids management and research

An individual's perception of risk develops from his or her values, beliefs, and experiences. Social scientists have identified factors that affect perceptions of risk, such as whether the risk is knowable (uncertainty), voluntary (can the individual control exposure?), and equitable (how fairly is the risk distributed?). There are measurable differences in how technical experts and citizen stakeholders define and assess risk. Citizen knowledge and technical expertise are both relevant to assessing risk; thus, the 2002 National Research Council panel on biosolids recommended stakeholder involvement in biosolids risk assessments. A survey in 2002 identified some of the factors that influence an individual's perception of the risks involved in a neighbor's use of biosolids. Risk communication was developed to address the gap between experts and the public in knowledge of technical topics. Biosolids management and research may benefit from applications of current risk communication theory that emphasizes (i) two-way communications (dialogue); (ii) that the public has useful knowledge and concerns that need to be acknowledged; and (iii) that what may matter most is the credibility of the purveyor of information and the levels of trustworthiness, fairness, and respect that he or she (or the organization) demonstrates, which can require cultural change. Initial experiences in applying the dialogue and cultural change stages of risk communication theory--as well as consensus-building and joint fact-finding--to biosolids research suggest that future research outcomes can be made more useful to decision-makers and more credible to the broader public. Sharing control of the research process with diverse stakeholders can make research more focused, relevant, and widely understood.