Detection of trisomy 21 by quantitative fluorescent–polymerase chain reaction in uncultured amniocytes

Prenatal diagnosis of fetal trisomy 21 is usually performed by cytogenetic analysis. This requires lengthy laboratory procedures, high costs and is unsuitable for large-scale screening of pregnant women. Today, trisomy 21 can be rapidly diagnosed within 24 h by molecular analysis of uncultured fetal cells using the semi-quantification of fluorescent PCR products from short tandem repeat (STR) polymorphic markers. The aim of our study was to test a chromosome quantification method on the basis of the analysis of fluorescent PCR products derived from non-polymorphic target genes. Co-amplification of a portion of DSCR1 (Down syndrome Critical Region 1) and the reference gene, CFTR (cystic fibrosis transmembrane regulator) enabled molecular detection of trisomy 21. Our method was successfully tested on a total of 154 amniotic fluids in a blind prospective study. Calculation of the DSCR1/CFTR ratio allowed us to distinguish between 152 normal amniotic fluids (mean ratio 0.99) and 2 amniotic fluids presenting a trisomy 21 status (DSCR1/CFTR ratio of 1.53 and 1.61, respectively). The results obtained by conventional cytogenetic analysis and our quantitative PCR method were concordant in every case. Our gene-based fluorescent PCR approach represents an alternative molecular method for rapid and reliable detection of trisomy 21, which can be helpful in the prenatal diagnosis of women at high risk of fetal trisomy 21. Copyright © 2003 John Wiley & Sons, Ltd.     

Ice Shelf Microbial Ecosystems in the High Arctic and Implications for Life on Snowball Earth

 The Ward Hunt Ice Shelf (83°N, 74°W) is the largest remaining section of thick (>10 m) landfast sea ice along the northern coastline of Ellesmere Island, Canada. Extensive meltwater lakes and streams occur on the surface of the ice and are colonized by photosynthetic microbial mat communities. This High Arctic cryo-ecosystem is similar in several of its physical, biological and geochemical features to the McMurdo Ice Shelf in Antarctica. The ice-mats in both polar regions are dominated by filamentous cyanobacteria but also contain diatoms, chlorophytes, flagellates, ciliates, nematodes, tardigrades and rotifers. The luxuriant Ward Hunt consortia also contain high concentrations (10⁷–10⁸ cm^–2) of viruses and heterotrophic bacteria. During periods of extensive ice cover, such as glaciations during the Proterozoic, cryotolerant mats of the type now found in these polar ice shelf ecosystems would have provided refugia for the survival, growth and evolution of a variety of organisms, including multicellular eukaryotes. Received: 30 August 1999 / Accepted in revised form: 15 December 1999     

Isolation and characterization of naphthenic acids from Athabasca oil sands tailings pond water

A laboratory bench procedure was developed to efficiently extract naphthenic acids from bulk volumes of Athabasca oil sands tailings pond water (TPW) for use in mammalian oral toxicity testing. This solvent-based procedure involved low solvent losses and a good extraction yield with low levels of impurities. Importantly, labour-intensive centrifugation of source water to remove solids was avoided, allowing processing of much larger volumes of water compared with previous protocols. Naphthenic acids, present at an estimated concentration of 81 mg/l, were procured from 515.5 l of TPW at an overall extraction efficiency of approximately 85%. By using distillation to recover and recycle solvent, a high solvent:water ratio was maintained while actual solvent consumption was limited to 70 ml per liter of water processed. Electrospray ionization mass spectrometry suggested a highly heterogeneous naphthenic acid mixture that exhibited nearly identical proportions of monocyclic, polycyclic, and acyclic acids with molecular weights primarily between 220 and 360. Biphenyls, naphthalenes, and phenanthrene/anthracene were the most prominent impurities detected, but their levels were low (< or = 13 microg/l) even in a concentrated solution of the naphthenic acids (8549 mg/l). Naphthenic acids stored at 4 degrees C at this concentration were stable, exhibiting no significant change in concentration over a 10-month period. This bulk isolation procedure should be useful to others needing to process large volumes of tailings or other source water for the purpose of procuring moderate amounts of naphthenic acids.     

Fossil evidence for the early ant evolution

Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.     

Local policies for reducing the ecological impact of households: the case study of a suburban area in France

Since Rio, governments have increased measures to promote sustainable household consumption, but this has induced limited changes in consumers’ daily practices. This article argues that one of the reasons behind the poor efficiency of these policies is the low level of consideration granted to local decision-making. The article discusses the results of a study which aims at better ascertaining the practices and representations of local government leaders in promoting sustainable development in households. We shall analyse the motivations, obstacles, interaction of players, communication and action plans associated with promoting sustainable development, in which individual will and effort are the keywords. The results obtained show how important it is to introduce better management systems for information and resource exchange between the different institutions involved. The study was carried out in a suburban area of south-west France counting 71 small towns and villages, characteristic of the spatial dynamics triggered by the global phenomenon of urbanisation.     

Genetic heterogeneity among <Emphasis Type="Italic">Eurytemora affinis</Emphasis> populations in Western Europe

Evolutionary diversification of the broadly distributed copepod sibling species complex Eurytemora affinis has been documented in the northern hemisphere. However, the fine scale geographic distribution, levels of genetic subdivision, evolutionary, and demographic histories of European populations have been less explored. To gain information on genetic subdivision and to evaluate heterogeneity among European populations, we analyzed samples from 8 locations from 58° to 45°N and 0° to 23°E, using 549 base pairs of the mitochondrial cytochrome oxidase subunit I (COI) gene. We discovered three distinct lineages of E. affinis in Western Europe, namely the East Atlantic lineage, the North Sea/English Channel (NSEC) lineage, and the Baltic lineage. These geographically separated lineages showed sequences divergence of 1.7–2.1%, dating back 1.9 million years (CI: 0.9–3.0 My) with no indication of isolation by distance. Genetic divergence in Europe was much lower than among North American lineages. Interestingly, genetic structure varied distinctively among the three lineages: the East Atlantic lineage was divided between the Gironde and the Loire populations, the NSEC lineage comprised one single population unit spanning the Seine, Scheldt and Elbe rivers and the third lineage was restricted to the Baltic Proper (Sweden). We revealed high haplotype diversity in the East Atlantic and the Baltic lineages, whereas in the NSEC lineage haplotype diversity was comparatively low. All three lineages showed signs of at least one demographic expansion event during Pleistocene glaciations that marked their genetic structure. These results provide a preliminary overview of the genetic structure of E. affinis in Europe.     

A high pressure liquid chromatographic method for the analysis of zearalenone in chicken blood

Abstract

A high pressure liquid chromatographic (HPLC) method is described to determine zearalenone in chicken blood. Samples are extracted with acetonitrile, followed by a hexane cleanup procedure and extracted further with ethyl acetate. The analysis of zearalenone is by HPLC using a reverse phase radial compression separation system, an ultraviolet absorbance detector and a mobile phase of acetonitrile‐water 60:40 (v/v). Recoveries of zearalenone in blood at levels of 50–200 ng/ml are in the range of 66.8–72.6%.     

Moral Entrepreneurship: Resource Based Ethics

This article studies the role of entrepreneurship in business ethics and promotes a resource-based ethics. The need for and usefulness of this form of ethics emerge from an analysis of contemporary business ethics that appears to be inefficacious and from a moral business practice formed out of the relationship between the veal calf industry of the VanDrie Group and the Dutch Society for the Protection of Animals (DSPA) in their development and implementation of a Welfare Hallmark for calves. Both organizations created jointly a new meat segment in the market by trust-building and partnership. The relationship shows a remodeling of capabilities of both organizations in the light of co-creation of values. The VanDrie Group established an effectuation of moral goals by being socially sensitive and resource-minded. The DSPA created openings for dialogue by being pragmatic in its ideals. Philosophically, this article sketches a resource-based ethics with Deweyan concepts as end-in-view and transactionality of means and ends. Both organizations show in their entrepreneurship the ability to create, what is called “Room for Maneuver” by exploring, socializing, individualizing, and growing. By maneuvering they set off a form of co-evolution between business and ethics. This article demonstrates what actual moral entrepreneurship can do in bringing about moral change by combining effectively social, policy, norm, and economic related values.     

Coping with insularity: the need for crop genetic improvement to strengthen adaptation to climatic change and food security in the Pacific

The capability of Pacific Island countries’ agriculture to adapt to climatic and environmental changes is analysed. After presenting key features of the region’s food cropping systems, findings of genetic diversity studies for the most important food crops are reviewed and their implications for adaptation are discussed. Biophysical and economic vulnerabilities of the food system are identified. For the major food crops, the needs for genetic improvement are detailed, and practical solutions for broadening genetic bases are suggested. The paper concludes by identifying areas for additional research on crops and agro-ecosystems adaptation aiming at increasing the flexibility of agriculture in the Pacific. In this region, plant breeding has to cope with the insularity constraints of the small island states. The new varieties need to satisfy farmers’ agronomic requirements in very diverse environments. However, because of genotype-by-environment interactions (G × E), it is difficult to identify a variety that would be accepted by most farmers on different islands. A new type of breeding programme with a pragmatic approach is therefore necessary. The geographical distribution of allelic diversity appears as a practical and cost-efficient solution.