Prenatal diagnosis of mosaicism for triploidy and trisomy 13

Mosaicism for trisomy 13 and triploidy was detected by amniocentesis performed at 18 weeks' gestation because of fetal anomalies. Pregnancy continued and a live-born male was delivered vaginally at 37 weeks. The infant had features common to both trisomy 13 and triploidy: intrauterine growth retardation (IUGR), small abnormal ears, cleft palate, and a small jaw. In addition, he had complete cutaneous syndactyly of fingers 3 and 4 and partial syndactyly of the toes, as seen in triploidy. Mixoploidy for trisomy 13 and triploidy was confirmed postnatally in blood, skin, and placenta. Examination of chromosome heteromorphisms and DNA markers suggested the presence of two maternal contributions in the triploid cell line. In addition, the extra chromosome 13 in the trisomic cell line was derived from the mother. Copyright © 2001 John Wiley & Sons, Ltd.     

The need for and meaning of positive organizational behavior

This essay draws from the emerging positive psychology movement and the author's recent articles on the need for and meaning of a positive approach to organizational behavior. Specifically, the argument is made that at this time, the OB field needs a proactive, positive approach emphasizing strengths, rather than continuing in the downward spiral of negativity trying to fix weaknesses. However, to avoid the surface positivity represented by the non‐sustainable best‐sellers, the case is made for positive organizational behavior (POB) to take advantage of the OB field's strength of being theory and research driven. Additional criteria for this version of POB are to identify unique, state‐like psychological capacities that can not only be validly measured, but also be open to development and performance management. Confidence, hope, and resiliency are offered as meeting such POB inclusion criteria. The overall intent of the essay is to generate some positive thinking and excitement for the OB field and ‘hopefully’ stimulate some new theory building, research, and effective application. Copyright © 2002 John Wiley & Sons, Ltd.     

Biological Activity in a Heavily Organohalogen-Contaminated River Sediment (8 pp)

Background, Aims and Scope Sediments of the Spittelwasser creek are highly polluted with organic compounds and heavy metals due to the discharge of untreated waste waters from the industrial region of Bitterfeld-Wolfen, Germany over the course of more than one century. However, relatively few data have been published about the chloroorganic contamination of the sediment. This paper reports on the content of different (chloro)organic compounds with special emphasis on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), and chlorobenzenes. Existing concepts for the remediation of Spittelwasser sediment include the investigation of natural attenuation processes, which largely depend on the presence of an intact microbial food web. In order to gain more insight in terms of biological activity, we analyzed the capacity of sediment microflora to degrade organic matter by measuring the activities of extracellular hydrolytic enzymes involved in the biogeochemical cycling of carbon, nitrogen, phosphorus and sulfur. Furthermore, the detection of physiologically active bacteria in the sediment, particularly of those known for their capability to reductively dehalogenate organochlorine compounds, illustrates the potential for intrinsic bioremediation processes. Methods PCDD/F and chlorobenzenes were analyzed by gas chromatography(GC)/mass spectrometry and GC/flame ionization detection, respectively. The activities of hydrolytic enzymes were determined from freshly sampled sediment layers using 4-methylumbelliferyl (MUF) or 7-amino-4-methylcoumarin-conjugated model compounds and kinetic fluorescence measurements. Physiologically active bacteria from different sediment layers were microscopically visualized by fluorescence in situ hybridization (FISH). Specific bacteria were identified by 16S rRNA gene amplification and sequencing. Results and Discussion The PCDD/F congener profile was dominated by dibenzofurans. In addition, the presence of specific tetra and pentachlorinated dibenzofurans supported the assumption that extensive magnesium production was one possible source for the high contamination. A range of other chloroorganic compounds, including several isomers of chlorobenzenes, hexachlorocyclohexane and 1,1,1-trichloro-2,2-bis (p-chloro-phenyl)ethane (DDT), was present in the sediment. Activities of extracellular hydrolytic enzymes showed a strong decrease in those sediment layers that were characterized by high contents of absorbable organic halogen (AOX), indicating disturbed organic matter decay. Interestingly, an abnormal increase of cellulolytic enzyme activities below the organochlorine-rich layers was observed, possibly caused by residual cellulose from discharges of sulfite pulping wastes. FISH revealed physiologically active bacteria in most sediment layers from the surface down to the depth of about 60 cm, including members of Desulfitobacterium (D.) and Sulfurospirillum. The presence of D. dehalogenans was confirmed by its partial 16S rRNA gene sequence. Conclusions Results of chemical sediment analyses demonstrated high loads of organochlorine compounds, particularly of PCDD/F. Several years after stopping the waste water discharge to Spittelwasser creek, this sediment remains a main source for pollution of the downstream river system by way of the ongoing mobilization of sediment during high floods. As indicated by our enzyme activity measurements, the decomposition potential for organic matter is low in organochlorine-rich sediment layers. In contrast, the comparably higher enzyme activities in less organochlorine-polluted sediment layers as well as the presence of physiologically active bacteria suggest a considerable potential for natural attenuation. Recommendations and Perspectives From our data we strongly recommend to explore the degradative capacity of sediment microorganisms and the limits for in situ activity towards specific sediment pollutants in more detail. This will give a sound basis for the integration of bioremediation approaches into general concepts to reduce the risk that permanently radiates from this highly contaminated sediment. Submission Editor: Dr. Henner Hollert (Henner.Hollert@urz.uniheidelberg.de)     

Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC–MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 – 1.277 ng/m³ in the air and <LOD – 1391.000 ng/m³ in surface waters. Based on the results, the means of Industrial Area, Dandora and Kibera were not significantly different (p≤ 0.05), but were higher (p≤ 0.05) than those of City square and Ngong’ Forest. The results revealed non-significant (p≤ 0.05) contribution of long-range transport to OCP pollution in Nairobi City. This indicated possible presence of point sources of environmental OCPs in the city. The water-air fugacity ratios indicated that volatilization and deposition played an important role in the spatial distribution of OCPs in Nairobi City. This indicated that contaminated surface waters could be major sources of human exposure to OCPs, through volatilization. The incremental lifetime cancer risks (ILCR) determined from inhalation of atmospheric OCPs were 2.3745  ×  10^?13 – 1.6845  ×  10^?11 (adult) and 5.5404  ×  10^?13 – 3.9306  ×  10^?11 (child) in the order: Dandora > Kibera > Industrial Area > City Square > Ngong’ Forest. However, these were lower than the USEPA acceptable risks, 10^?6 – 10^?4. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.     

Reducing car-based journeys to work: What potential is there and whose responsibility is it?

To date the transport solutions seeking to reduce traffic impacts have tended to focus on city/town centres. There has, however, been a substantial increase in traffic levels both in and to suburban areas and the location of large employment sites in such areas has had a significant impact. The typical policy response to traffic in these areas has been the introduction of traffic calming measures and residents' parking but such policies do not address the fundamental issue of travel generation and its consequences (including parking). Major employers should have an important role to play in the consideration of more sensible and sustainable uses of the car including the promotion of alternatives to car use. Using a case study at a large institution in Oxford this paper examines findings from a survey into staff travel behaviour in order to identify how staff currently behave. It explores the potential for transport and non-transport solutions to reduce car-based journeys to work and concludes that there is real potential to encourage a reduction in car-based travel. The paper seeks to widen the debate about who should take responsibility for achieving such a reduction. It argues that whilst travel awareness campaigns primarily push responsibility onto individuals an 'integrated package' is required with employers also assuming responsibility and thereby enabling individuals to adapt.     

Progress toward remediation of the Sydney Tar Ponds: A major Canadian PCB/PAH “superfund” site

The Muggah Creek estuary in Sydney, Nova Scotia, received liquid and solid wastes from a steel mill and its associated coke ovens for approximately 100 years. This resulted in pollution of soils and sediments with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), heavy metals, and other pollutants, including those in untreated domestic wastewaters. The Canadian federal and Nova Scotia provincial governments organized the Sydney Tar Ponds Agency (STPA) to develop a remediation approach for the Coke Ovens site soils and Sydney Tar Ponds sediments. The STPA developed a remediation approach for the Sydney Tar Ponds sediments, involving solidification/stabilization (S/S) through mixing cement and other materials into the sediments, and then capping them as a waste pile. High‐density polyethylene (HDPE) plastic sheeting vertical barriers are proposed to be used to divert groundwater and surface water from entering into the S/S‐treated sediments and to collect any water and associated pollutants released from the S/S‐treated sediments. The Coke Ovens site soils are proposed to be landfarmed to reduce some of the PAHs and other pollutants and then capped with a layer of soil. This remediation program is estimated to cost on the order of $400 million (CAN). This article presents a review of the significant potential problems with the STPA proposed remediation strategy of the Sydney Tar Ponds sediments and Coke Ovens site soils. © 2006 Wiley Periodicals, Inc.     

Superfund site remediation by landfilling—overview of landfill design,operation, closure,and postclosure issues

This article discusses the appropriateness of using landfills as part of remediating hazardous chemical and Superfund sites, with particular emphasis on providing for true long‐term public health and environmental protection from the wastes and contaminated soils that are placed in the landfills. On‐site landfilling or capping of existing wastes is typically the least expensive approach for gaining some remediation of existing hazardous chemical/Superfund sites. The issues of the deficiencies in US EPA and state landfilling approaches discussed herein are also applicable to the landfilling of municipal and industrial solid “nonhazardous” wastes. These deficiencies were presented in part as “Problems with Landfills for Superfund Site Remediation” at the US EPA National Superfund Technical Assistance Grant Workshop held in Albuquerque, New Mexico, in February 2003. They are based on the author's experience in investigating the properties of landfill liners and the characteristics of today's landfills, relative to their ability to prevent groundwater pollution and to cause other environmental impacts. Discussed are issues related to both solid and hazardous waste landfills and approaches for improving the ability of landfills to contain wastes and monitor for leachate escape from the landfill for as long as the wastes in the landfill will be a threat. © 2004 Wiley Periodicals, Inc.     

Transforming open mining pits into fish farms: Moving towards sustainability

The legacy of mining activities has typically been land ‘returned to wildlife’, or, at some sites, degraded to such an extent that it is unsuitable for any alternate use. Progress towards sustainability is made when value is added in terms of the ecological, social and economic well‐being of the community. In keeping with the principles of sustainable development, the innovative use of flooded open pits and tailings impoundments as commercial, recreational or ornamental fish farms should be considered in some locations, as it could make a significant contribution to the social equity, economic vitality and environmental integrity of mining communities. This article highlights the growing significance of aquaculture and explores the benefits and barriers to transforming flooded pits and impoundments into aquaculture operations. Among other benefits, aquaculture may provide a much‐needed source of revenue, employment and, in some cases, food to communities impacted by mine closure. Further, aquaculture in a controlled closed environment may be more acceptable to critics of fish farming who are concerned about fish escapes and viral transmissions to wild populations. Despite the potential benefits, aquaculture in flooded pits and impoundments is not without its complications — it requires a site‐specific design approach that must consider issues ranging from metals uptake by fish, to the long‐term viability of the aquatic system as fish habitat, to the overall contribution of aquaculture to sustainability.