Life history of the nematode Theristus anoxybioticus from sublittoral muddy sediment at methane seepages in the northern Kattegat,Denmark

Field and laboratory studies from 1989 to 1994 of the nematode Theristus (Penzancia) anoxybioticus Jensen, 1995 inhabiting muddy sediment at methane seepages in the northern Kattegat, Denmark, have revealed a series of biological features of adults and juveniles not observed before in free-living marine nematodes. Reproductive adults were present in April and May only and inhabited the uppermost cm of sediment, while juveniles inhabited deep anoxic and sulphidic sediment layers during the remaining months of the year. This points to a downwards migration of newly hatched juveniles and an upwards migration during adulthood. Gut content analyses showed that adults feed mainly on benthic diatoms by swallowing whole cells while juveniles probably feed on bacteria; this differentiation in food clearly relates to the main bulk of potential food items in their respective microhabitats. The generation time is estimated to be one year, with a juvenile life span of about nine months, which is four to eight times longer than that found in related aerobic species of similar body size. Adults survived in oxic water but 50% died within 15 h in hypoxic water (5 to 6% atm sat), and all died within 12 h in anoxic water. Juveniles on the other hand died within 0.5 h in oxic water but survived anoxic water for at least 15 d. These results suggest that juveniles of T. anoxybioticus are adapted to an anaerobic life style.     

Methyl jasmonate improves radical generation in macrophyte phytoremediation

Phytoremediation is the use of plants to decontaminate and improve waters and soils. Pleustonic macrophytes are plant models for research in waters. In a phytoremediation study, the elicitation of Pistia stratiotes with methyl jasmonate or salicylic acid suggests that oxytetracycline modification rate coefficients could be increased more than threefold. Here we present the elicitation of Pistia stratiotes apical primary root tips. We detected reactive oxygen species generation by X-band electron paramagnetic resonance spectroscopy, using the spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). Elicitation using 0.8 mM methyl jasmonate during 1 h increased the relative spin-trapped radical concentration by +12 %. Further, results indicate acute plant toxicity above 0.24 mM salicylic acid.     

Aerobic and anaerobic transformations of sulfide in a sewer system--field study and model simulations.

The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation in the force main was significant. However, during 14 minutes of transport in the gravity sewer, the sulfide concentration decreased 30%, on average. An application of a conceptual sewer process model for simulating the formation and fate of sulfide was demonstrated. Overall, the model predicted that approximately 90% of the decrease of the sulfide concentration in the gravity sewer was the result of sulfide oxidation and that only a small fraction entered the sewer atmosphere, causing odor and corrosion. Even so, the model predicted concrete corrosion rates of up to 1.2 mm/y in the gravity sewer section.     

Evaluation and ranking of restoration strategies for radioactively contaminated sites.

An international project, whose aim was the development of a transparent and robust method for evaluating and ranking restoration strategies for radioactively contaminated sites (RESTRAT), was carried out under the Fourth Framework of the Nuclear Fission Safety Programme of the EU. The evaluation and ranking procedure used was based on the principles of justification and optimisation for radiation protection. A multi-attribute utility analysis was applied to allow for the inclusion of radiological health effects, economic costs and social factors. Values of these attributes were converted into utility values by applying linear utility functions and weighting factors, derived from scaling constants and expert judgement. The uncertainties and variabilities associated with these utility functions and weighting factors were dealt with by a probabilistic approach which utilised a Latin Hypercube Sampling technique. Potentially relevant restoration techniques were identified and their characteristics determined through a literature review. The methodology developed by this project has been illustrated by application to representative examples of different categories of contaminated sites; a waste disposal site, a uranium tailing site and a contaminated freshwater river.     

BSE in the UK: Why the Risk Communication Strategy Failed

The 2000 BSE Inquiry report points out that the most serious failure of the UK Government was one of risk communication. This paper argues that the government's failure to communicate the risks BSE posed to humans to a large degree can be traced back to a lack of transparency in the first risk assessment by the Southwood Working Party. This lack of transparency ensured that the working party's risk characterization and recommendations were ambiguous and thus hard to interpret. It also meant that uncertainties were not addressed in a satisfactory way. In the recommendations, the attitude to uncertainty was implicit rather than explicit.The risk communication based on the report amplified these flaws. Most importantly, it did not address the uncertainty at all. Apparently, the reason for this was fear of overreaction by the public. However, the result was counter-productive, because the risk communication did not then appear trustworthy. Later risk assessments and risk communication omitted to correct these flaws. Indeed, the fact that, following receipt of new information, advisory experts and policy makers had changed their views of the risk to humans was never clearly communicated to the public. There seemed to be little faith in the public's ability to reach a balanced judgment regarding the uncertainties.In the concluding section of the paper, this analysis is compared with the food standards agency's (FSA's) approach to BSE. The intervention of this agency was seen as one of the more important efforts to restore consumer confidence in British beef. And the agency certainly appears to be committed to openness and to addressing scientific uncertainty. However, using the risk of BSE in sheep as a case study, the paper shows that transparency – i.e., the clear presentation of factual and normative claims and assumptions underlying advice, and openness about the reasoning based on these claims and assumptions – is less than fully achieved in the FSA's work.     

Leveraging foodways for health and justice

ABSTRACT

The global industrial food system is increasingly recognised as a source of poor health that deepens social and economic inequity. Health advocates, policy makers, and food activists strive to improve nutrition and food access across racial and ethnic divides; however, given established approaches, they may miss fundamental pathways for improving health and justice comprehensively. While food access and nutrition are often identified as primary concerns for marginalised communities and the reason for food insecurity and food-related illness, critical food justice scholars use a more expansive lens to suggest a democratised food system is needed, and that solutions based solely in access to healthy food can undermine more systemic approaches. Our research extends this analysis, highlighting the importance of endemic food culture (foodways) as a tool for retaining identity, building community, and maintaining health among refugee populations in one community in Salt Lake City, Utah. Further, this work suggests that community engagement and expertise is essential in leveraging foodways such that marginalised communities can effectively resist cheap, unhealthy, and placeless calories.     

Vivianite precipitation and phosphate sorption following iron reduction in anoxic soils

Phosphorus retention in lowland soils depends on redox conditions. The aim of this study was to evaluate how the Fe(III) reduction degree affects phosphate adsorption and precipitation. Two similarly P-saturated, ferric Fe-rich lowland soils, a sandy and a peat soil, were incubated under anaerobic conditions. M?ssbauer spectroscopy demonstrated that Fe(III) in the sandy soil was present as goethite and phyllosilicates, whereas Fe(III) in the peat soil was mainly present as polynuclear, Fe-humic complexes. Following anoxic incubation, extensive formation of Fe(II) in the solids occurred. After 100 d, the Fe(II) production reached its maximum and 34% of the citrate-bicarbonate-dithionite extractable Fe (Fe(CBD)) was reduced to Fe(II) in the sandy soil. The peat soil showed a much faster reduction of Fe(III) and the maximum reduction of 89% of Fe(CBD) was reached after 200 d. Neoformation of a metavivianite/vivianite phase under anoxic conditions was identified by X-ray diffraction in the peat. The sandy soil exhibited small changes in the point of zero net sorption (EPC?) and P(i) desorption with increasing Fe(III) reduction, whereas in the peat soil P desorption increased from 80 to 3100 μmol kg?1 and EPC? increased from 1.7 to 83 μM, after 322 d of anoxic incubation. The fast Fe(III) reduction made the peat soils particularly vulnerable to changes in redox conditions. However, the precipitation of vivianite/metavivianite minerals may control soluble P(i) concentrations to between 2 and 3 μM in the long term if the soil is not disturbed.     

Antimicrobial activities of extracts from tropical Atlantic marine plants against marine pathogens and saprophytes

Studies investigating disease resistance in marine plants have indicated that secondary metabolites may have important defensive functions against harmful marine microorganisms. The goal of this study was to systematically screen extracts from marine plants for antimicrobial effects against marine pathogens and saprophytes. Lipophilic and hydrophilic extracts from species of 49 marine algae and 3 seagrasses collected in the tropical Atlantic were screened for antimicrobial activity against five ecologically relevant marine microorganisms from three separate kingdoms. These assay microbes consisted of the pathogenic fungus Lindra thalassiae, the saprophytic fungus Dendryphiella salina, the saprophytic stramenopiles, Halophytophthora spinosa and Schizochytrium aggregatum, and the pathogenic bacterium Pseudoaltermonas bacteriolytica. Overall, 90% of all species surveyed yielded extracts that were active against one or more, and 77% yielded extracts that were active against two or more assay microorganisms. Broad-spectrum activity against three or four assay microorganisms was observed in the extracts from 48 and 27% of all species, respectively. The green algae Halimeda copiosa and Penicillus capitatus (Chlorophyta) were the only species to yield extracts active against all assay microorganisms. Among all assay microorganisms, both fungi were the most resistant to the extracts tested, with less than 21% of all extracts inhibiting the growth of either L. thalassiae or D. salina. In contrast, over half of all lipophylic extracts were active against the stramenopiles H. spinosa and S. aggregatum, and the bacterium P. bacteriolytica. Growth sensitivity to hydrophilic extracts varied considerably between individual assay microorganisms. While 48% of all hydrophilic extracts were active against H. spinosa, 27% were active against P. bacteriolytica, and only 14% were active against S. aggregatum. Overall, more lipophilic extracts inhibited microbial growth than hydrophilic extracts. The variability observed in the antimicrobial effects of individual extracts against each assay microorganism reflects the importance of choosing appropriate test microbes in assays from which ecologically relevant information is sought. Results from this survey demonstrate that antimicrobial activities are prevalent among extracts from marine algae and seagrasses, suggesting that antimicrobial chemical defenses are widespread among marine plants.     

Stabilization of APC residues from waste incineration with ferrous sulfate on a semi-industrial scale

A stabilization method for air pollution control (APC) residues from municipal solid waste incineration (MSWI) involving mixing of the residue with water and FeSO4 has been demonstrated on a semi-industrial scale on three types of APC residues: a semidry (SD) APC residue, a fly ash (FA), and an FA mixed with sludge (FAS) from a wet flue gas cleaning system. The process was performed in batches of 165-175 kg residue. It generates a wastewater that is highly saline but has a low content of heavy metals such as Cd, Cr, and Pb. The stabilized and raw residues have been subject to a range of leaching tests: the batch leaching test, the pH-static leaching test, the availability test, and the column test. These tests showed that the stabilized residues have remarkably improved leaching properties, especially with respect to Pb but also with respect to Cd, Cu, and Zn. The release of Pb was reduced by a factor of 250-36,000.