Fetal marfan syndrome: Prenatal ultrasound diagnosis with pathological confirmation of skeletal and aortic lesions

Sonography was performed during the second trimester in two pregnancies at risk for the Marfan syndrome. In one, the limbs were significantly longer than expected (p < 0·0025) and a diagnosis of the Marfan syndrome was established. Pathological examination of the fetus after pregnancy interruption showed typical foci of cystic medial necrosis in the ascending aorta.     

Isolated choroid plexus cysts—the need for routine offer of karyotyping

The management of isolated fetal choroid plexus cysts remains controversial. We have prospectively studied 15 565 pregnancies at two large obstetric units for the presence of choroid plexus cysts. In all cases where cysts were present at 19 weeks' gestation or greater, and were multiple, bilateral or solitary and greater than 5 mm maximum diameter, women were offered amniocentesis or placental biopsy, irrespective of the presence or absence of other abnormalities. Choroid plexus cysts were present in 152 (0·98 per cent) of cases. Four cases (2·6 per cent) of autosomal trisomy (three of trisomy 18, one of trisomy 21) were detected on prenatal karyotyping. In all cases, choroid plexus cysts were the only detectable prenatal anomaly. This study and a review of other large studies do not support the view that isolated choroid plexus cysts are a benign variant, the risk of trisomy being 1 in 82. Until further evidence is available, we recommend that cases of isolated fetal choroid plexus cysts at 19 weeks' gestation or greater should be offered prenatal karyotyping.     

The need for flexibility in freshwater treaty regimes

Shrinking freshwater supplies pose particular threats in international drainage basins, which serve some 40% of the global population and account for around 60% of the world's river flows. The use and management of these basins are increasingly governed by treaties between the riparian states. While the rules of international law, properly understood, are sufficiently flexible to permit adaptation to changing conditions such as development, population growth and climate change, treaties are essentially rigid instruments that are modifiable only under certain limited conditions. Countries should take this fact into account in designing the regimes to govern their shared freshwater resources, including joint management institutions.     

REEXAMINING BEST MANAGEMENT PRACTICES FOR IMPROVING WATER QUALITY IN URBAN WATERSHEDS1

ABSTRACT: Municipalities will be implementing structural best management practices at increasing rates in their effort to comply with Phase II of the National Pollutant Discharge Elimination System (NPDES). However, there is evidence that structural best management practices (BMPs) by themselves may be insufficient to attain desired water quality standards. This paper reports on an analysis of the median removal efficiencies of structural BMPs and compares them to removal efficiencies estimated as being necessary to attain water quality standards in the Rouge River in Detroit, Michigan. Eight water quality parameters are reviewed using data collected from 1994 to 1999 in the Rouge River. Currently, five of the eight parameters in the Rouge River including bacteria, biochemical oxygen demand, and total suspended solids (TSS) exceed the required water quality standards. The reported analysis of structural BMP efficiencies reveals that structural BMPs appear capable of reducing only some of the pollutants of concern to acceptable levels.     

Dynamics of P, Al, and Fe during High Discharge Episodic Acidification at the Bear Brook Watershed in Maine, U.S.A.

Phosphorus (P), aluminum (Al), and iron (Fe) stream chemistry were assessed for high discharge snowmelt events at the Bear Brook Watershed, Maine (BBWM) during December 2001 and February 2002 and compared with results from a January 1995 study of the same streams. The West Bear catchment has been subjected to artificial acidification since 1989. The East Bear catchment is the untreated reference. Total (acid soluble) Al, Fe, and P were positively correlated with discharge during the 2001–2002 events. However, dissolved P concentrations remained low (≤0.1 μmol L^-1) during high discharge events as pH decreased in both streams.For example, in 2001, total P concentration increased to 1.7 μmol L^-1 during the rising limb of the hydrograph in West Bear, approximately five times the value in East Bear. During the same event, in West Bear and East Bear dissolved Al concentrations increased to 21 and 6.3 μmol L^-1, respectively, while total Al concentrations increased to 166 and 30 μmol L^-1, respectively. Dissolved Fe concentrations remained ≤0.9 μmol L^-1 in both streams during all study events. However, total Fe concentrations in 2001 increased to 239 and 4.1 μmol L^-1 for West Bear and East Bear, respectively. Total Al and Fe declined parallel to total P after peaking during all study periods. Nearly all of the base cations were in dissolved form during the three events, indicating that total Al in West and East Bear Brooks is not associated with primary minerals such as feldspars. We conclude that particulate Al, Fe, and P are chemically linked during transport at high discharge in these episodically and chronically acidified streams.     

Sustainable development and the community: Lessons from the KASHA project,botswana

Summary This paper focuses on the characteristics of sustainable development as manifested in localized contexts and situations. It examines the KASHA project in Botswana, and suggests an important conceptual link between the community and sustainable development. To convey the message that there is hope and that "Sustainable Development" is possible, the paper suggests the need to document, share, describe and talk about successful programmes like KASHA.Dr Stephen Ameyaw is currently Assistant Professor of Planning in the Faculty of Environmental Design, University of Calgary. His research interests are focused on women and development, community development, regional planning, policy and institutional development. He has conducted research in Canada, Ghana and Botswana.     

Stable isotopes provide new insights into vestimentiferan physiological ecology at Gulf of Mexico cold seeps

On the otherwise low-biomass seafloor of the Gulf of Mexico (GoM) continental slope, natural oil and gas seeps are oases of local primary production that support lush animal communities. Hundreds of seep communities have been documented on the continental slope, and nutrition derived from seeps could be an important link in the overall GoM food web. Here, we present a uniquely large and cohesive data set of δ(13)C, δ(15)N, and δ(34)S compositions of the vestimentiferan tubeworms Escarpia laminata and Lamellibrachia sp. 1, which dominate biomass at GoM seeps and provide habitat for hundreds of other species. Our sampling design encompassed an entire region of the GoM lower slope, allowing us for the first time to assess spatial variability in isotope compositions and to robustly address long-standing hypotheses about how vestimentiferans acquire and cycle nutrients over their long lifespan (200+?years). Tissue δ(13)C values provided strong evidence that larger adult vestimentiferans use their buried roots to take up dissolved inorganic carbon from sediment pore water, while very small individuals use their plume to take up carbon dioxide from the seawater. δ(34)S values were extremely variable among individuals of the same species within one location (<1?m(2) area), indicating high variability in the inorganic sulfur pools on a very small spatial scale. This finding supports the hypothesis that vestimentiferans use their roots to cycle sulfate and sulfide between their symbionts and free-living consortia of sulfate-reducing archaea in the sediment. Finally, consistent differences in δ(15)N between two cooccurring vestimentiferan species provided the first strong evidence for partitioning of inorganic resources, which has significant implications for the ecology and evolution of this taxonomic group.     

Book reviews

Toward Sustainable Communities: resources for citizens and their governments. Mark Roseland with Maureen Cureton & Heather Wornell, 1998, Gabriola Island, New Society Publishers, ISBN 0 86571 374 X, $18.95

First Mover Advantage by Eco-efficiency: local incentives for environment and employment.. C. Erdmunger & S. Schreckenberger, 1998, Freiburg, ICLEI, DM30

Agendas for Sustainability: environment and development into the twenty-first century. Mary Macdonald, 1998, London, Routledge, ISBN 0 415 15491X, £55.00 (hbk)

Women, Population and Global Crisis: a political-economic analysis. Asoka Bandarage, 1997, London, Zed Books, ISBN 1 85649 428 4, £15.95 (pbk)

Spirit of the Environment: religion, value, and environmental concern. David Cooper & Joy Palmer (Eds), 1998, London, Routledge, ISBN 0 4151 4202 4, £12.99 (pbk)

Environmental Transition in Nordic and Baltic Countries. Hans Aage (Ed.), 1998, (New Horizons in Environmental Economics). Cheltenham, UK and Northampton, MA, USA, Edward Elgar, ISBN 1 85898 629 X

Sustainability Indicators: measuring the immeasurable. Simon Bell & Stephen Morse, 1999, London, Earthscan Publications, 175 pp. ISBN 1 85383 498 X, LE14.95 (pbk)

The Economics of Road Transport Regulation. Erik Verhoef, Cheltenham, Edward Elgar 1996, 265 pp. ISBN 1 85898 364 9, £55.00

The Water Crisis. Julie Stauffer, London, Earthscan, 1998, ISBN 185383 436X, £12.95 (pbk)     

Why Economics Matters for Endangered Species Protection

Abstract: We offer three reasons why economics matters more to species protection than many people think and what this implies for the ongoing debate over the reauthorization of the Endangered Species Act of 1973. Economics matters because (1) human behavior generally, and economic parameters in particular, help determine the degree of risk to a species; (2) in a world of scarce resources, the opportunity cost of species protection—the costs of reduced resources for other worthwhile causes—must be taken into account in decision making; and (3) economic incentives are critical in shaping human behavior, and consequently the recovery of species. Endangered species protection that explicitly addresses these basic principles can avoid wasting valuable resources that yield no gain in species protection.     

Predator diversity and ecosystem functioning: density modifies the effect of resource partitioning

The link between biodiversity and ecosystem functioning is now well established, but the challenge remains to develop a mechanistic understanding of observed effects. Predator-prey interactions provide an opportunity to examine the role of resource partitioning, thought to be a principal mediator of biodiversity-function relationships. To date, interactions between multiple predators and their prey have typically been investigated in simplified agricultural systems with limited scope for resource partitioning. Thus there remains a dearth of studies examining the functional consequences of predator richness in diverse food webs. Here, we manipulated a species-rich intertidal food web, crossing predator diversity with total predator density, to simultaneously examine the independent and interactive effects of diversity and density on the efficiency of secondary resource capture. The effect of predator diversity was only detectable at high predator densities where competitive interactions between individual predators were magnified; the rate of resource capture within the species mixture more than doubled that of the best-performing single species. Direct observation of species-specific resource use in monoculture, as quantified by patterns of prey consumption, provided clear evidence that species occupied distinct functional niches, suggesting a mechanistic explanation of the observed diversity effect.