Prenatal diagnosis of congenital cytomegalovirus infection in 189 pregnancies with known outcome

An Erratum has been published for this article in Prenatal Diagnosis 21(7) 2001, 605. Prenatal diagnosis (PD) of fetal cytomegalovirus (CMV) infection was performed in 242 pregnancies, with known outcome in 189 cases. In 141/189 pregnancies, PD was carried out on account of suspicious maternal CMV serology up to gestational week (WG) 23, and in 48 cases on account of abnormal ultrasonic findings detected between WG 18 and 39. Chorionic villus samples (n=6), amniotic fluid (AF, n=176) and/or fetal blood specimens (n=80) were investigated for detection of virus by cell culture, shell vial assay, PCR and/or CMV-specific IgM antibodies. Of 189 fetuses correctly evaluated by CMV detection either in fetal tissue following therapeutic abortion/stillbirth (n=24) or in urine of neonates within the first 2 weeks of life (n=33), 57 were congenitally infected. In women with proven or suspected primary infection, the intrauterine transmission rates were 20.6% (7/34) and 24.4% (10/41), respectively. Of the congenitally infected live-born infants, 57.6% (19/33) had symptoms of varying degree. The overall sensitivity of PD in the serologic and ultrasound risk groups was 89.5% (51/57). A sensitivity of 100% was achieved by combining detection of CMV-DNA and CMV-specific IgM in fetal blood or by combined testing of AF and fetal blood for CMV-DNA or IgM antibodies. There was no instance of intrauterine death following the invasive procedure. The predictive value of PD for fetal infection was 95.7% (132/138) for negative results and 100% (51/51) for positive results. Correct results for congenital CMV infection by testing AF samples can be expected with samples obtained after WG 21 and after a time interval of at least 6 weeks between first diagnosis of maternal infection and PD. In case of negative findings in AF or fetal blood and the absence of ultrasound abnormalities at WG 22–23, fetal infection and neonatal disease could be excluded with high confidence. Positive findings for CMV infection in AF and/or fetal blood in combination with CMV suspicious ultrasound abnormalities predicted a high risk of cytomegalic inclusion disease (CID). Furthermore, detection of specific IgM antibodies in fetal blood was significantly correlated with severe outcome for the fetus or the newborn (p=0.0224). However, normal ultrasound of infected fetuses at WG 22–23 can neither completely exclude an abnormal ultrasound at a later WG and the birth of a severely damaged child nor the birth of neonates which are afflicted by single manifestations at birth or later and of the kind which are not detectable by currently available ultrasonographic techniques. Copyright © 2001 John Wiley & Sons, Ltd.     

A field intercomparison and fundamental characterization of various dust samplers with a reference sampler

The European Economic Community Council Directive 80/779/EEC describes air quality limit values and guide values for sulfur dioxide and suspended particulates. However, article 10, paragraph 1 does not define well enough the reference method required, amongst others, for the gravimetric measurement of suspended particulates. It is explicity stated in article 10, paragraph 5 of the directive, that "the commission shall, in selected locations in the member states and in cooperation with the latter, carry out studies on the sampling...of suspended particulates. These studies shall be designed in particular to promote the harmonization of methods of sampling and analysis of these pollutants." Therefore, in a joint research program the Umweltbundesamt (grant #104 02263), the commission of European Communities (grant #84-B-6642-11-017-11-N) and the U.S. EPA (grant #2-432U-3580) funded the development of a reference dust sampler by the Fraunhofer-Institute of Toxicology and Aerosol Research (FhlTA, in Hannover, Federal Republic of Germany) in order: to study the particle size distribution of ambient air aerosol at a number of selected sites; to compare the results obtained with the reference dust sampler with those of particle samplers operated in Europe and the United States; to verify the applicability of wind tunnel results to sampling behaviour in the free atmosphere.     

Biotic habitat complexity controls species diversity and nutrient effects on net biomass production

Canopy-forming plants and algae commonly contribute to spatial variation in habitat complexity for associated organisms and thereby create a biotic patchiness of communities. In this study, we tested for interaction effects between biotic habitat complexity and resource availability on net biomass production and species diversity of understory macroalgae by factorial field manipulations of light, nutrients, and algal canopy cover in a subtidal rocky-shore community. Presence of algal canopy cover and/or artificial shadings limited net biomass production and facilitated species diversity. Artificial shadings reduced light to levels similar to those under canopy cover, and net biomass production was significantly and positively correlated to light availability. Considering the comparable and dependent experimental effects from shadings and canopy cover, the results strongly suggest that canopy cover controlled net biomass production and species diversity by limiting light and thereby limiting resource availability for community production. Canopy cover also controlled experimental nutrient effects by preventing a significant increase in net biomass production from nutrient enrichment recorded in ambient light (no shading). Changes in species diversity were mediated by changes in species dominance patterns and species evenness, where canopy cover and shadings facilitated slow-growing crust-forming species and suppressed spatial dominance by Fucus vesiculosus, which was the main contributor to net production of algal biomass. The demonstrated impacts of biotic habitat complexity on biomass production and local diversity contribute significantly to understanding the importance of functionally important species and biodiversity for ecosystem processes. In particular, this study demonstrates how loss of a dominant species and decreased habitat complexity change the response of the remaining assembly to resource loading. This is of potential significance for marine conservation since resource loading often promotes low habitat complexity and canopy species are among the first groups lost in degraded aquatic systems.     

Statistical characteristics of selected elements in vegetables from Kosovo

Zinc, copper, iron, chromium and cobalt are essential elements for human health, showing toxicity only in high concentrations, while lead and cadmium are extremely toxic even as traces. Therefore, it is important to monitor the contents of toxic metals in vegetables. Large number of vegetables is grown and used in nutrition, in Kosovo. The concentrations of selected elements in vegetables (radish, onion, garlic and spinach) from Kosovo were determined using ICP-OES method. Oral intake of metals and health risk index were calculated. Statistical analysis indicated numerous positive correlations between concentrations of selected elements in vegetables. As a result of principal component analysis, 15 new variables were obtained which were characterized by eigenvalues. The sequence of health quotients for the heavy metals followed the decreasing order Zn?=?Mn?>?Pb?>?Cu?>?Ni?>?Fe?>?Cd?>?Co?>?Cr. The health quotients for all investigated heavy metals were below 1 (one), which is considered safe. The vegetables from Kosovo are mainly safe for use in everyday diet.     

Learning from local knowledge: modeling the pastoral-nomadic range management of the Himba, Namibia.

It is widely accepted that successful grazing management strategies in semiarid ecosystems need to be adapted to the highly temporal and spatially heterogeneous forage production. Nevertheless, a full understanding of the key factors and processes for sustainable adaptive management has yet to be reached. The investigation of existing, successful range management systems by simulation models may help to derive general understanding and basic principles. The semi-nomadic Himba in northern Namibia applied a sophisticated management system until the mid-1990s which combined season-dependent pasture use (resulting in rainy-season pastures and dry-season pastures), preservation of reserves for drought and sanctions for rule breaking. A stochastic ecological simulation model has been developed here which represents the main aspects of this management system. With this model we analyze (1) which components of the traditional Himba strategy are essential for sustainability and (2) what happens to the state of the rangeland system under socioeconomic changes. This study shows that temporally and spatially heterogeneous pasture use yields higher productivity and quality of a pasture area than the pressure of homogeneous permanent grazing. Two aspects are of importance: (1) intra-annual heterogeneous use (resting of the dry-season pastures during the rainy season) and (2) interannual heterogeneous use (spatial extension of grazing in years of drought). This management system leads to an effective build-up and use of a buffer in the system: the reserve biomass (the non-photosynthetic reserve organs of the plants), an indicator for grazing and management history. Analyzing purchase as one form of socioeconomic change, we demonstrate that easier market access to purchase livestock may lead to a decline in vegetation quality. However, cattle production increases as long as rest periods on parts of the pasture during the rainy season are granted. Methodologically, we emphasize that simulation models offer an excellent framework for analyzing and depicting basic principles in sustainable range management derived from local knowledge. They provide the opportunity of testing whether these basic principles are also valid under different ecological and socioeconomic settings.     

Elevated alpha-fetoprotein and human chorionic gonadotropin as a marker for placental trisomy 16 in the second trimester?

In a series of 2961 consecutive cases with second-trimester biochemical triple screening for Down's syndrome and neural tube defect (NTD), ten (0.3 per cent) showed an apparent increased risk for both conditions. Three cases had chromosomal abnormalities, namely trisomy 16 confined to the placenta. Since placental trisomy 16 as well as cases with increased alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) are associated with (intrauterine growth retardation (IUGR), oligohydramnios, and fetal demise, at least some cases with this atypical biochemical profile could be explained by this chromosomal abnormality. From our results we recommend that in cases with increased risk for both Down's syndrome and NTD, fetal karyotyping should preferably be done on a placental biopsy, especially when ultrasound in the absence of anomalies demonstrates early IUGR.     

Adaptation to environmental stress in Daphnia magna simultaneously exposed to a xenobiotic

In standardized ecotoxicological testing chemicals are investigated under optimal conditions for the test organisms despite the fact that environmental factors such as predation pressure and food availability are important parameters regulating natural populations. Food limitation and predator presence can induce shifts in life-history traits in various Daphnia species, especially trade-offs in reproductive biomass allocation. These adaptive responses are thought to ensure survival of the population in a highly variable environment. A xenobiotic dispersant (used in textile dyeing processes) also shifted the biomass allocation of Daphnia magna. To assess whether the dispersant could hinder D. magna adaptation to varying environmental conditions, we conducted experiments with food level and presence of Chaoborus larvae as environmental factors and simultaneous exposure to the dispersant. At low food level and in presence of the predator, D. magna produced fewer but larger sized neonates, regardless of dispersant exposure. The dispersant shifted biomass allocation towards more but smaller sized offspring in all experiments. However, the adaptive response to the environmental factors and the dispersant effect cancelled each other out in that they induced independently from each other opposite shifts in biomass allocation. In summary, the dispersant exposure resulted not in an inhibition of the adaptive response but in a reduction of the value of the response. Our study with this model substance demonstrates that xenobiotics can affect the adaptation of organisms to environmental stress which can result in effects likely to be overlooked in standardized testing.     

Imprecision in waggle dances of the honeybee (Apis mellifera) for nearby food sources: error or adaptation?

A curious feature of the honeybee's waggle dance is the imprecision in the direction indication for nearby food sources. One hypothesis for the function of this imprecision is that it serves to spread recruits over a certain area and thus is an adaptation to the typical spatial configuration of the bees' food sources, i.e., flowers in sizable patches. We report an experiment that tests this tuned-error hypothesis. We measured the precision of direction indication in waggle dances advertising a nest site (typically a tree cavity, hence a target that is almost a point) and compared it with that of dances advertising a food source (typically a flower patch, hence a target that covers an area). The precision of dances for a nearby nest site was significantly higher than that of dances for an equidistant feeder. This was demonstrated four times with four colonies. Our evidence therefore supports the hypothesis that the level of precision in the direction indication for nearby food sources is tuned to its optimum without being at its maximum. Received: 9 December 1998 / Received in revised form: 24 February 1999 / Accepted 12 March 1999     

A strategy for the next decade to address data deficiency in neglected biodiversity

Measuring progress toward international biodiversity targets requires robust information on the conservation status of species, which the International Union for Conservation of Nature (IUCN) Red List of Threatened Species provides. However, data and capacity are lacking for most hyperdiverse groups, such as invertebrates, plants, and fungi, particularly in megadiverse or high-endemism regions. Conservation policies and biodiversity strategies aimed at halting biodiversity loss by 2020 need to be adapted to tackle these information shortfalls after 2020. We devised an 8-point strategy to close existing data gaps by reviving explorative field research on the distribution, abundance, and ecology of species; linking taxonomic research more closely with conservation; improving global biodiversity databases by making the submission of spatially explicit data mandatory for scientific publications; developing a global spatial database on threats to biodiversity to facilitate IUCN Red List assessments; automating preassessments by integrating distribution data and spatial threat data; building capacity in taxonomy, ecology, and biodiversity monitoring in countries with high species richness or endemism; creating species monitoring programs for lesser-known taxa; and developing sufficient funding mechanisms to reduce reliance on voluntary efforts. Implementing these strategies in the post-2020 biodiversity framework will help to overcome the lack of capacity and data regarding the conservation status of biodiversity. This will require a collaborative effort among scientists, policy makers, and conservation practitioners.