Ecologically based management of rodents in the real world: applied to a mixed agroecosystem in Vietnam.

Rodents cause significant damage to lowland irrigated rice crops in the Red River Delta of Vietnam. A four-year study was conducted in 1999-2002 to examine the effectiveness of applying rodent control practices using the principles of ecologically based pest management. Four 100-150 ha study sites adjacent to villages were selected and farmers on two treated sites were asked to follow a set of rodent management practices, while farmers on the untreated sites were asked not to change their typical practices. Farmers on the treated sites were encouraged to use trap-barrier systems (TBS's; 0.065-ha early planted crop surrounded by a plastic fence with multiple capture traps; one TBS for every 10-15 ha), to work together over large areas by destroying burrows in refuge habitats soon after planting (before the rats reestablish in the fields and before the onset of breeding), synchronizing planting and harvesting of the their rice crops, cleaning up weeds and piles of straw, and keeping bund (embankment) size small (<30 cm) to prevent burrowing. A 75% reduction in the use of rodenticides and plastic barrier fences (without traps or an early crop) was achieved on treated sites. The abundance of rodents was low after implementation of the management practices across all sites. There was no evidence for an effect of treatment on the abundance of rodents captured each month using live-capture traps, and no difference in damage between treatments or in yields obtained from the rice crops. Therefore, ecologically based rodent management was equally effective as typical practices for rodent management. Farmers on the treated sites spent considerably less money applying rodent control practices, which was reflected in the comparative increase in the partial benefit:cost of applying ecologically based rodent management from 3:1 on treated sites and untreated sites prior to the implementation of treatments to 17:1 on treated sites in the final year of the project.     

Source apportionment of airborne fine particulate matter in an underground mine

The chemical mass balance source apportionment technique was applied to an underground gold mine to assess the contribution of diesel exhaust, rock dust, oil mists, and cigarette smoke to airborne fine (<2.5 microm) particulate matter (PM). Apportionments were conducted in two locations in the mine, one near the mining operations and one near the exit of the mine where the ventilated mine air was exhausted. Results showed that diesel exhaust contributed 78-98% of the fine particulate mass and greater than 90% of the fine particle carbon, with rock dust making up the remainder. Oil mists and cigarette smoke contributions were below detection limits for this study. The diesel exhaust fraction of the total fine PM was higher than the recently implemented mine air quality standards based on total carbon at both sample locations in the mine.     

First world-wide interlaboratory study on polybrominated diphenylethers (PBDEs)

The first world-wide interlaboratory study on PBDEs, organised between November 1999 and April 2000, involved five biological samples, two sediments and two standard solutions. These materials were sent to 26 participants in nine different countries. Results were returned from 18 laboratories. The results reported for BDE 47 were acceptable with a range of relative standard deviations (Rsd) of 17-40%. Results for the BDEs 99 (Rsd 25-77%), BDE 100 (Rsd 19-48%), 153 (Rsd 30-48%) and 154 (Rsd 25-43%) showed that a further improvement of these analyses is needed. The BDE 209 analysis is not under the control of the participating laboratories. The data reported for the biota samples were very variable and for the two sediments Rsd values of 48% and 78% were obtained. It is recommended that analysts pay more attention to the special requirements for the BDE 209 analysis such as avoiding exposure to intensive light and exposure for too long times to too high temperatures.     

Simple nomenclature for chlorinated camphenes and dihydrocamphenes from which structural information can be directly deduced

The systematic nomenclature for chlorinated camphenes and dihydrocamphenes is rather complicated and confusing. Therefore, a simple structure-related nomenclature is proposed for these compounds, which is based on the same logic as was recently used for the chlorinated bornanes, bomenes and bornadienes. Although final IUPAC rules for the systematic nomenclature for camphenes and dihydrocamphenes have not yet been presented, the present nomenclature can be used for retrieving the correct conformation without the help of extensive tables or computer programmes, and vice versa. When the final IUPAC rules will be presented, the present nomenclature can easily be adjusted, if necessary     

Long-term effects of submergence and wetland vegetation on metals in a 90-year old abandoned Pb-Zn mine tailings pond

A Pb-Zn tailings pond, abandoned for approximately 90 years, has been naturally colonized by Glyceria fluitans and is an excellent example of long-term metal retention in tailings ponds under various water cover and vegetation conditions. Shallow/intermittently flooded areas (dry zone) were unvegetated and low in organic matter (OM) content. Permanently flooded areas were either unvegetated with low OM, contained dead vegetation and high OM, or living plants and high OM. It was expected that either water cover or high OM would result in enhanced reducing conditions and lower metal mobility, but live plants would increase metal mobility due to root radial oxygen loss. The flooded low OM tailings showed higher As and Fe mobility compared with dry low OM tailings. In the permanently flooded areas without live vegetation, the high OM content decreased Zn mobility and caused extremely high concentrations of acid-volatile sulfides (AVS). In areas with high OM, living plants significantly increased Zn mobility and decreased concentrations of AVS, indicating root induced sediment oxidation or decreased sulfate-reduction. This is the first study reporting the ability of wetland plants to affect the metal mobility and AVS in long-term (decades), unmanaged tailings ponds.     

Preconception and preimplantation diagnosis for cystic fibrosis

Preimplantation diagnosis provides couples at high genetic risk the possibility of avoiding genetic disease without the need for prenatal diagnosis and selective abortion of the affected pregnancy. Following extensive background work on the reliability of genetic diagnosis in a single cell, we offered on a research basis preimplantation diagnosis to five couples at risk for offspring with the delta-F508 mutation (the major mutation causing cystic fibrosis). There was no detrimental effect from polar body removal on either fertilization or preimplantation development. Genetic analysis, undertaken in 22 polar bodies and 15 corresponding blastomeres, identified 21 embryos of which ten were transferred.     

Prenatal ultrasonic diagnosis of radial-ray aplasia and renal anomalies (acro-renal syndrome)

Prenatal ultrasonic diagnosis of a rare case of radial ray aplasia and crossed renal ectopy is described in an affected sibling of a family where the father and his son suffer from this rare syndrome. The prenatal diagnosis enabled early pregnancy termination.     

Prospective intervention trial of a screening protocol to identify fetal trisomy 18 using maternal serum alpha-fetoprotein,unconjugated oestriol,and human chorionic gonadotropin

Two prenatal centres in New England, routinely using a screening protocol for fetal Down syndrome that included maternal serum alpha-fetoprotein (AFP), unconjugated oestriol (uE3), and human chorionic gonadotropin (hCG) measurements in combination with maternal age, adopted a separate screening protocol for trisomy 18. That protocol identified a pregnancy as being at high risk when AFP, uE3, and hCG measurements all fell at or below specified cut-offs (0.75, 0.60, and 0.55 multiples of the median, respectively), regardless of maternal age. Among the first 19 491 women screened, 98 (0.5 per cent) were found to have values which placed them in the high-risk category. Four of these women were subsequently found not to be pregnant. In two others, samples from non-pregnant individuals were found to have been incorrectly submitted for analysis in place of the samples from the pregnant women. All of the remaining 92 women were counselled and offered amniocentesis and fetal karyotyping. Eighty-eight (96 per cent) accepted. Karyotypes or birth outcomes were available on all 92 pregnancies. Six cases of trisomy 18 and one case of Turner syndrome were identified by karyotype. One case of trisomy 18 was identified for every 14 unaffected pregnancies offered amniocentesis. In the present prospective study, an estimated 85 per cent of the cases of trisomy 18 were identified. However, given the small number ofcases (six), the 95 per cent confidence interval for the detection rate is broad (40–95 per cent).     

Better regulation by new governance hybrids? Governance models and the reform of European chemicals policy

The EU is presently in a transition phase from environmental policy-making by law towards other governance approaches based upon networking, voluntary commitments, benchmarking and other forms of “soft law”. Those new governance approaches often claim to lead to “better regulation”, while adopting a more consensus-oriented and participatory style, taking economic aspects more seriously into account, allowing for more flexibility and autonomy for the private sector and Member States alike, mobilising a broader knowledge base or adopting more integrated and holistic approaches than previous sectoralised and compartmentalised policies.While the limitations of traditional regulatory approaches are widely accepted and cited, it is far from evident, that “new modes of governance” have greater capacity to solve problems than the old ones. There is an argument, that “better regulation” might by synonymous to a withdrawal and weakening of the regulatory state and hence effectively of the aspirations and objectives of environmental policies.An interesting case for an approach, combining the strengths of the old and the new approaches is the ongoing reform of chemicals policies. While some observers claim, that the proposed directive, “REACH” might belong to the outdated category of overcomplex and bureaucratic regulation, a closer look shows that there are many new forms of governance in REACH. This mixture or old and new may open a more realistic and promising perspective on the reform of European policy-making.In our paper we assess the effects and the interplay of the combination of different modes of governance using the example of REACH. We are particularly concerned with the question in how far the representation of interests may change when new modes of governance are introduced.