Demonstration of spontaneously dividing male fetal cells in maternal blood by negative magnetic cell sorting and fish

We investigated a case of massive feto-maternal bleeding by using negative magnetic cell sorting (MACS) and fluorescent in situ hybridization (FISH). A 37-year-old pregnant woman had an uncomplicated amniocentesis for advanced maternal age at 16 weeks' gestation. The fetal karyotype was 46, XY. At 19 weeks' gestation, she had a minor car accident and slight vaginal bleeding. A subsequent Kleihauer-Betke test showed a 140 ml feto-maternal haemorrhage. Serial sonographic examinations indicated a normal fetus and placenta. We performed FISH analysis on maternal peripheral blood at 25 weeks. Anti-CD45 and MACS were used to deplete maternal leucocytes, enriching the proportion of fetal nucleated erythrocytes present. The isolated cells were analysed by using dual-colour FISH with X and Y specific probes. Approximately 65 800 nucleated cells were obtained after MACS depletion. A total of 234 cells were analysed by FISH. The results revealed that 70 of the nucleated cells (30 per cent) were male with one X and one Y signal. Among these cells, six male metaphases were observed in spontaneously dividing cells.     

Diet induced differences in carbon isotope fractionation between sirenians and terrestrial ungulates

Carbon isotope differences (Δ¹³C) between bioapatite and diet, collagen and diet, and bioapatite and collagen were calculated for four species of sirenians, Dugong dugon (Müller), Trichechus manatus (Linnaeus), Trichechus inunguis (Natterer), and the extinct Hydrodamalis gigas (Zimmerman). Bone and tooth samples were taken from archived materials collected from populations during the mid eighteenth century (H. gigas), between 1978 and 1984 (T. manatus, T. inunguis), and between 1997 and 1999 (D. dugon). Mean Δ¹³C values were compared with those for terrestrial ungulates, carnivores, and six species of carnivorous marine mammals (cetaceans = 1; pinnipeds = 4; mustelids = 1). Significant differences in mean δ¹³C values among species for all tissue types were detected that separated species or populations foraging on freshwater plants or attached marine macroalgae (δ¹³C values < −6‰; Δ¹³C_{bioapatite–diet} ∼14‰) from those feeding on marine seagrasses (δ¹³C values > −4‰; Δ¹³C_{bioapatite–diet} ∼11‰). Likewise, Δ¹³C_{bioapatite–collagen} values for freshwater and algal-foraging species (∼7‰) were greater than those for seagrass-foraging species (∼5‰). Variation in Δ¹³C values calculated between tissues and between tissues and diet among species may relate to the nutritional composition of a species’ diet and the extent and type of microbial fermentation that occurs during digestion of different types of plants. These results highlight the complications that can arise when making dietary interpretations without having first determined species-specific Δ¹³C_{tissue–diet} values. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Compensatory wayfinding behavior in topographic disorientation from brain injury

Recent studies of topographic disorientation from brain injury have focused on describing impairments, detailing neuroanatomical correlates of topographic disorientation, and classifying types of topographic disorientation. Normative models of environmental cognition have been applied in some studies of topographic disorientation, but more work is needed in this area. Few studies have produced data on everyday functioning with topographic disorientation. This paper presents data on compensatory wayfinding behavior in familiar environments, collected through case studies of three individuals with topographic disorientation from brain injury. Structured tests were used to evaluate visuo-spatial impairment, and normative models of wayfinding guided semi-structured and open-ended questioning about wayfinding inside and outside the home. All three-study informants were able to wayfind successfully within the home, though they varied in their ability to travel independently outside the home. Landmarks and scanning were important for orienting for all three subjects. The two subjects who were most able to travel independently also used sequencing of landmarks, directional heading and body position as elements of their wayfinding strategies. The information presented in this paper may prove useful to rehabilitation specialists who are treating brain-injured patients by providing new ideas about methods of compensation, and may contribute to emerging theory regarding impairments of orientation, and normative models of wayfinding.     

Reciprocal Model for Meeting Ecological and Human Needs in Restoration Projects

Abstract: Ecological restoration aims to reverse the losses of biodiversity and the degradation of ecosystems that have occurred through time as humans have affected landscapes. To date, however, restoration success has been limited, in spite of increasing ecological knowledge and technical skills. Technical constraints, although significant, are only part of the problem. The reasons for restoration failure, including cost constraints, limitations in land allocation, and insufficient time and labor, often involve underlying human obstacles. Unless such obstacles are overcome, ongoing commitment to restoration projects will likely remain limited. Because restoration involves diverse scientific and social interests and is often laden with conflicting priorities, we view it as a "wicked problem." We examine ways commitment to restoration could be increased by developing beneficial relationships between humans and the natural environment in the context of restoration. We propose a model that shows that the ecological needs of the restoration area have the greatest potential to be met when human contributions are greatest. In turn, humans benefit increasingly as the restored ecosystem recovers. As human needs are addressed over time, their potential contributions to the restoration area increase. The extent to which contributions meet needs is enhanced or constrained by factors ranging from available technology and funding to community support. This ongoing loop of interactions between needs and contributions provides a basis for restoration planning and implementation which potentially reduces both ecological and human roadblocks to success. The model suggests that community-based projects will be most successful when experts train the group in restoration decision making, when expertise and leadership are developed within the group, and when participants experience group cohesiveness and a sense of personal reward.     

Estimating digestion time in gelatinous predators: a methodological comparison with the scyphomedusa Aurelia aurita

In order to quantify the trophic impact of gelatinous predators, digestion time estimates are commonly applied to counts of prey in the guts. Three primary approaches are used, the Manual-feeding, Natural-feeding and Steady-state methods; these differ in methodology and their underlying assumptions. The criteria used to define the end-point of digestion, and the resolution at which digestion progress is observed, also vary across studies. To understand the impact of such differences, we estimate digestion times of the scyphomedusa Aurelia aurita fed adult females of the copepod Acartia tonsa using these various approaches. We find ~fourfold differences which can be attributed to bias towards the slowest rates of digestion by some end-point criteria, and overestimation from low observation resolution. Artificial manipulation and the degree to which swimming and feeding behaviour are natural may also influence estimates. We provide recommendations for those quantifying digestion times of Aurelia aurita medusae and gelatinous predators.     

Successful solid-phase bioremediation of petroleum-contaminated soil

Biological processes have been used to remediate petroleum hydrocarbons, pesticides, chlorinated solvents, and halogenated aromatic hydrocarbons. Biological treatment of contaminated soils may involve solid-phase, slurry-phase, or in situ treatment techniques. This article will review the general principle of solid-phase bioremediation and discuss the application of this technique for the cleanup of total petroleum hydrocarbons on two sites. These remedial programs will reduce total petroleum hydrocarbon contamination from the mean concentration of 2,660 ppm to under the 200-ppm cleanup criteria for soil and under the 15-ppm cleanup criteria for groundwater. Over 32,000 yards of soil have been treated by solid-phase treatment to date. The in situ system operation is effectively producing biodegradation in the subsurface. The project is approximately one-third complete.     

Exploring the current status of water governance and outcomes of community-based monitoring across the Oak Ridges Moraine,Southern Ontario,Canada

ABSTRACT

Community-based monitoring (CBM) activities are becoming increasingly prevalent in response to multiple factors, including reduced governmental capacity and increased public interest in environmental management. This research aims to explore how CBM has evolved in the Oak Ridges Moraine (ORM), southern Ontario, including an examination of strengths and challenges. Interviews with CBM stakeholders, provincial government staff, and conservation authority staff were combined with document analysis to explore the evolution and outcomes of ORM CBM activities. Results indicate that there is active CBM on the ORM and conservation authorities play a role in the shaping of CBM activities, although significant barriers remain to civil society participation in water governance. The case study results from the ORM were also considered in light of research emerging from the Nova Scotia experience of numerous civil society organisations involved in CBM.     

Cumulative impact of GM herbicide-tolerant cropping on arable plants assessed through species-based and functional taxonomies

Background, aim and scope

In a gradualist approach to the introduction of crop biotechnology, the findings of experimentation at one scale are used to predict the outcome of moving to a higher scale of deployment. Movement through scales had occurred for certain genetically modified herbicide-tolerant (GMHT) crops in the UK as far as large-scale field trials. However, the land area occupied by these trials was still <1% of the area occupied by the respective non-GM crops. Some means is needed to predict the direction and size of the effect of increasing the area of GMHT cropping on ecological variables such as the diversity among species and trophic interactions. Species-accumulation curves are examined here as a method of indicating regional-scale impacts on botanical diversity from multiple field experiments.

Materials and methods

Data were used from experiments on the effect of (GMHT) crops and non-GM, or conventional, comparators in fields sown with four crop types (beet, maize, spring and winter oilseed rape) at a total of 250 sites in the UK between 2000 and 2003. Indices of biodiversity were measured in a split-field design comparing GMHT with the farmers’ usual weed management. In the original analyses based on the means at site level, effects were detected on the mass of weeds in the three spring crops and the proportion of broadleaf and grass weeds in winter oilseed rape, but not on indices of plant species diversity. To explore the links between site means and total taxa, accumulation curves were constructed based on the number of plant species (a pool of around 250 species in total) and the number of plant functional types (24), inferred from the general life-history characteristics of a species.

Results

Species accumulation differed between GMHT and conventional treatments in direction and size, depending on the type of crop and its conventional management. Differences were mostly in the asymptote of the curve, indicative of the maximum number of species found in a treatment, rather than the steepness of the curve. In winter oilseed rape, 8% more species were accumulated in the GMHT treatment, mainly as a result of the encouragement of grass species by the herbicide when applied in the autumn. (Overall, GMHT winter oilseed rape had strong negative effects on both the food web and the potential weed burden by increasing the biomass of grasses and decreasing that of broadleaf weeds.) In maize, 33% more species—a substantial increase—were accumulated in the GMHT than in the conventional, consistent with the latter’s highly suppressive weed management using triazine herbicides. In the spring oilseed rape and beet, fewer species (around 10%) were accumulated in the GMHT than the conventional. The GMHT treatments did not remove or add any functional (life history) types, however. Differences in species accumulation between treatments appeared to be caused by loss or gain of rarer species. The generality of this effect was confirmed by simulations of species accumulation in which the species complement at each of 50 sites was drawn from a regional pool and subjected to reducing treatment at each site. Shifts in the species-accumulation parameters, comparable to those measured, occurred only when a treatment removed the rarer species at each site.

Discussion

Species accumulation provided a set of simple curve-parameters that captured the net result of numerous local effects of treatments on plant species and, in some instances, the balance between grass and broadleaf types. The direction of effect was not the same in the four crops and depended on the severity of the conventional treatment and on complex interactions between season, herbicide and crop. The accumulation curves gave an indication of potential positive or negative consequences for regional species pools of replacing a conventional practice with GMHT weed management. In this and related studies, a range of indicators, through which diversity was assessed by both species and functional type, and at both site and regional scales, gave more insight into effects of GMHT treatment than provided by any one indicator.

Conclusions

Species accumulation was shown to discriminate at the regional scale between agronomic treatments that had little effect on species number at the field scale. While a comprehensive assessment of GM cropping needs to include an examination of regional effects, as here, the costs of doing this in all instances would be prohibitive. Simulations of diversity-reducing treatments could provide a theoretical framework for predicting the likely regional effects from in-field plant dynamics.

Recommendations and perspectives

Accumulation curves potentially offer a means of linking within-site effects to regional impacts on biodiversity resulting from any change in agricultural practice. To guide empirical measurement, there is a scope to apply a methodology such as individual-based modelling at the field scale to explore the links between agronomic treatments and the relative abundance of plant types. The framework needs to be validated in practice, using species-based and functional taxonomies, the latter defined by measured rather than inferred traits.