Effects of invertebrate predators and a pesticide on temporary pond microcosms used for aquatic toxicity testing

The effects of increased trophic complexity, through the addition of predatory notonectids (Anisops deanei), on temporary pond microcosms used for aquatic toxicity testing were studied. Replicate microcosms were established using sediment from a dried temporary pond, and treated with one of four concentrations of the organochlorine pesticide endosulfan (0, 1, 10 or 50 microg/L), in the presence or absence of six A. deanei. The tanks were sampled regularly for nine weeks following the addition of the predators and the entire contents of each tank counted after 12 weeks. Analysis using non-metric multidimensional scaling (MDS) and non-parametric MANOVA showed that both Anisops and endosulfan at concentrations >10 microg/L significantly altered community structure. However, an interaction between the effects of Anisops and the effects of endosulfan was not detected. The addition of Anisops did not increase the variability of response and thus did not reduce the sensitivity of the test method.     

Collaborative networks and new ways of knowing

To move beyond legal and regulatory gridlock around water issues in the California Bay-Delta, a new inter-agency initiative, commonly known as CALFED, was created in 1994. CALFED has been an ongoing experiment in policy innovation. Part of the change in management practice has involved constructing new arenas that engage multiple perspectives and transform regulatory impasse into provisional steps forward. We examine the construction of so-called boundary objects, which are forums and policy instruments that cross group boundaries and foster integrative deliberation. We compare the design and action of two boundary objects created by CALFED, namely the Environmental Water Account (EWA) and the Water Use Efficiency (WUE) program. We find that the presence of the boundary object, in itself, does little to explain the success of each policy experiment. Rather, the answer lies in the types of network interactions that result, along with the way meaning is coproduced. In fact, rather than create new patterns of interrelationship (e.g., between fish habitat advocates and pump station operators), the boundary object might further embed institutionalized routines. To more deeply understand what makes the new institution an integrative one, we introduce the concept of Ways of Knowing which explains how new knowledge emerges from the network of new relationships.     

The toxicological paradigms of aluminum and the etiology of Alzheimer's disease in the nematode Caenorhabditis elegans

This study examined behavioral and enzymatic changes of C. elegans from its exposure to aluminum, and the resulting relationship with Alzheimer's disease. After chronic and acute exposure to aluminum, the results indicated that it alters the cholinergic status and behavior parameters of the nematode, suggesting a relationship between exposure to aluminum and the etiology of AD.     

Factors affecting conviction rates of intoxicated driver patients in two large trauma centers

Objective: Outcomes from previous studies report the driving under the influence (DUI) conviction rates for trauma patients in several cities within Canada and the United States over the last 2 decades. This study reports charge, conviction, and prosecution rates for trauma patients at 2 level I trauma centers servicing a large metropolitan city.

Methods: A retrospective review of the trauma databases was completed to identify patients meeting inclusion criteria. Four hundred sixty patients were identified and their records were compared with the district attorney's records for DUI charges and convictions.

Results: The conviction rate for this study was 8.7%, demonstrating continued low rates of conviction despite growing interest and public awareness of drinking and driving.

Conclusions: We discuss legal considerations that providers should consider when treating patients who have been drinking and driving.     

An Exploratory Study of Meanings of Risk Control for Long Term and Acute Effect Occupational Health and Safety Risks in Small Business Construction Firms

A qualitative study of employers' and employees' meanings of occupational health and safety (OHS) risk control was conducted among a sample of small businesses engaged in the Australian construction industry. Two OHS risks relevant to the construction industry were selected for study. One risk (falls from height) represented an immediate consequence, whereas the other (occupational skin disease) represented a long-term health effect. Meanings of the sources and control for these risks were explored during in-depth interviews. Participants perceived the immediate effect, falls from height OHS risk, as being more important in their workplaces than the delayed effect, skin disease OHS risk. The risk of falls from height was perceived to be controllable but requiring a great deal of effort to prevent, whereas there was a fatalistic resignation to the risk of occupational skin disease. Meanings of risk control for both occupational skin disease and falls from height focused on individual rather than technological risk controls. Organizational barriers to the adoption of technological OHS risk controls in the construction industry were identified.     

Primary site and initial products of ammonium assimilation in the symbiotic sea anemone Anemonia viridis

Invertebrates containing endosymbiotic dinoflagellate algae (zooxanthellae) retain excretory nitrogen, and many are able to take up ammonium from the surrounding seawater. However, the site of assimilation and role of nitrogen recycling between symbiont and host remains unclear. In the present study, ammonium uptake by the symbiotic sea anemone Anemonia viridis (Forskål) was examined by following the pathway of assimilation using ¹⁵N-enriched ammonium. Since zooxanthellae became enriched with ¹⁵N from ammonium at up to 17 times the rate of the host, they appear to be the primary site of assimilation. In the light, the rate of zooxanthellae enrichment at 20?M was twice that at 10?M, whereas the rate of host enrichment was not significantly affected by ammonium concentration. When anemones were incubated with [¹⁵N]ammonium in the dark, after 12?h without light the rate of enrichment was lowered in both zooxanthellae and host. However, while the enrichment of the host was significantly reduced when the light level was lowered from 300 to 150?μmol photons m^?2?s^?1, zooxanthellae enrichment was unchanged. Low molecular weight material from the zooxanthellae became enriched at 20 times the rate of that from the host, and enrichment was detected in the amino acids glutamate, glutamine, aspartate, alanine, glycine, phenylalanine, threonine, valine, tyrosine, and leucine from zooxanthellae. In the zooxanthellae, amino acids accounted for 65% of the total enrichment of low molecular weight material. Of the amino acids detected in zooxanthellae, over 90% of the enrichment was accounted for by glutamate, glutamine and aspartate. The enrichment of the amide group of glutamine was greater than that of the amine group of glutamate or glutamine, consistent with the glutamine synthetase/glutamine 2-oxoglutarate amidotransferase cycle as the mechanism of ammonium assimilation. To examine the flux of ¹⁵N from zooxanthellae to host, anemones were pulse-labelled with [¹⁵N]ammonium and then transferred to an unlabelled chase. Over a 2?h period there was no evidence for a flux of nitrogen from zooxanthellae to host. However, during the chase period, the enrichment of low molecular weight material declined and that of high molecular weight material increased in both zooxanthellae and host, indicating that protein was synthesized using ¹⁵N from ammonium in both components of the symbiosis. Again by using a pulse-chase system, it was found that glutamate was metabolised most rapidly by zooxanthellae, followed by (in order of decreasing rate of turnover) aspartate, alanine, glycine and valine (no data are available for glutamine). Unlike these amino acids, nitrogen was transferred to the essential amino acids phenylalanine and threonine, increasing their enrichment during the chase period. While recycled nitrogen is clearly important to this symbiosis, the mechanism by which it is cycled remains to be resolved.     

The victims of unsustainability: a challenge to sustainable development goals

Environmental unsustainability is due to both structural features and historically specific characteristics of industrial capitalism resulting in specific patterns of production and consumption, as well as population growth. Sustainability literature criticises the established corporate and political power hegemonies, interested in maintaining economic growth, as well as inability or unwillingness of citizen-consumers to counteract these hegemonic tendencies. Yet, official policies are still targeted at social and economic ‘development’ as a panacea for unsustainability challenges. Instead, renewed accent on social and economic objectives are outlined by a set of sustainable development goals (SDG) that include objectives of fighting poverty, promoting better health, reducing mortality, and stimulating equitable economic growth. What is less commonly critiqued is the underlying morality of unsustainability and ethical questions concerned with the ‘victims of unsustainability’ outside of socioeconomic discourse. The achievement of SDG goals, as will be further elaborated on in this article, is unlikely to lead to greater social equality and economic prosperity, but to a greater spread of unsustainable production and consumption, continuous economic as well as population growth that has caused environmental problems in the first place and further objectification of environment and its elements. This article argues that an invocation of ethical duty toward environment and its elements is required in order to move beyond the current status quo. Such ethical approach to unsustainability can effectively address the shortcomings of the mainstream sustainability discourse that is mainly anthropocentric and therefore fails to identify the correct locus of unsustainability.