Achieving Brownfields Clean Up at a Radium-Contaminated Site

One of the U.S. Army Corps of Engineer's (USACE) primary goals in the management of removal actions is to safely implement work activities and cost effectively clean up sites contaminated with residual radioactive materials. The US ACE has successfully pursued a removal action under the Brownfields Initiative at the Cuneo Press Site in Chicago, Illinois. The residual radioactive contamination at the site exceeded background radiation levels for the Chicago area. Residual quantities of Radium-226 (Ra-226) were detected during preremoval characterization surveys performed at the site. The aggressive removal action performed at the site demanded immediate and accurate radiological screening and exposure data. Radiological screening consisted of field monitoring using portable instruments and gamma spectroscopy analysis for Ra-226. The screening data provided verification of compliance to the off-site disposal facility waste acceptance criteria and the site clean up criteria. The screening data, along with the application of guidance presented in NUREG-1575, “Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)”, demonstrated that the removal action meet clean up criteria established by the Illinois Nuclear Regulatory Commission and the USACE.     

Feasibility of Phytoextraction to Clean Up Low-Level Uranium-Contaminated Soil

The potential to phytoextract uranium (U) from a sandy soil contaminated at low levels was tested in the greenhouse. Two soils were tested: a control soil (317 Bq ²³⁸U kg^-1) and the same soil washed with bicarbonate (69 Bq ²³⁸U kg^-1). Ryegrass (Lolium perenne cv. Melvina), Indian mustard (Brassica juncea cv. Vitasso), and Redroot Pigweed (Amarathus retroflexus) were used as test plants.

The annual removal of the soil activity with the biomass was less than 0.1%. The addition of citric acid (25 mmol kg^-1) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15000 kg ha^-1 and 10000 kg ha^-1, respectively, up to 3.5% and 4.6% of the soil activity could annually be removed with the biomass.

With a desired activity reduction level of 1.5 and 5 for the bicarbonate washed and control soil, respectively, it would take 10 to 50 years to attain the release limit.

A linear relationship between the plant ²³⁸U concentration and the ²³⁸U concentration in the soil solution of the control, bicarbonate-washed, or citric acid-treated soil points to the importance of the soil solution activity concentration in determining U uptake and hence to the importance of solubilising agents to increase plant uptake.

However, citric acid addition resulted in a decreased dry weight production (all plants tested) and crop regrowth (in case of ryegrass).     

Beyond Picturing Culture: A Critique of a Critique

Picturing Culture: Explorations of Film and Anthropology. Jay Ruby. Chicago: University of Chicago Press, 2000. 339 pp.     

Artificially Induced Symbiosis Between Marine Flagellates and Vertebrate Tissues in Culture*

SYNOPSIS. Algal symbiotes isolated from marine invertebrate hosts, and grown axenically in culture, have been successfully combined in artificial associations with chick fibroblasts and grunt (Haemulon sp.) fin explants. Growth (measured by cell numbers and chlorophyll a) is stimulated in both symbiotes and host cells. Studies of nitrogen uptake and exchange suggest that these artificial associations are similar to other, natural symbioses involving invertebrate hosts, e.g. the hermatypic corals.     

Meeting report: Symbiosis in Barcelona

The European Congress on Biotechnology brought together the top European and International scientists, biotechnologists, innovators and key biotech policy and decision makers in an unprecedented international meeting. The Congress was established in 1978 by and remains the main activity of the European Federation of Biotechnology (EFB). Taking place in Barcelona, September 16–19, 2007, the ECB 13 attracted over 1500 leading scientists and other senior participants, over 500 posters and more than a hundred exhibitors, from over 50 countries across Europe and beyond. From over a 150 presentations in 5 and more parallel sessions, only a small fraction can be highlighted in the scope of this short meeting report.     

Adventures in Symbiosis

A research adventure is described in which the symbiosis ofHydra and Chlorella is modeled with a novel computer program.The model faithfully simulates equilibrium populations of hydraand algae, and is used to discern the parameters which governthe stability of the symbiosis and its breakdown resulting fromeutrophication. The model reveals that amelioration of a nutrientlimitation causes symbiotic Chlorella to reduce fitness of hostcells, converting a stable mutualistic symbiosis into an unstableparasitic one.     

Distribution of Marine Red Yeasts in Shrimps and the Environments of Shrimp Culture

Populations of marine red yeast from shrimps and the environments of shrimp culture were investigated from various areas at Zhanjiang in China. All strains were studied for the production of biomass and carotenoids. We isolated 88 marine red yeast strains and the average populations of marine red yeast in seawater and the water from shrimp culture ponds were 70.0 and 172.4 CFU per 100 ml water, respectively. For shrimp samples, average populations of marine red yeast from gills, intestines, and stomachs were 178.0, 15.0, and 8.0 CFU per shrimp, respectively. The isolates were grouped into nine species belonging to three genera as follows: Rhodosporidium, Rhodotorula, and Sporidiobolus. R. sphaerocarpum had the highest average biomass yield (10.3 ± 0.88 g/l), followed by S. ruineniae (10.1 g/l) and Rh. mucilaginosa (9.9 ± 1.75 g/l). R. paludigenum had the highest average carotenoid yield (2.83 ± 0.589 mg/l), followed by S. pararoseus (2.72 mg/l) and R. sphaerocarpum (2.59 ± 0.454 mg/l). The results showed that marine red yeasts were normal microbial components in the environments of shrimp culture and shrimps, and carotenoids are abundant in these marine red yeast.     

加强医院廉政文化建设的探索

针对近年来社会反响突出的医院公益性发挥作用较弱,“看病难、看病贵”问题突出,医院作风建设亟待加强,医患矛盾凸显等现象,从自身建设入手,以廉政文化建设为抓手,通过“重宣传、建机制、强教育”,“创品牌、推改革、全体系”等措施,全面推进医院作风建设,收到了良好的实效,使医院建设发展与人民群众满意度同步提升,实现了社会效益与精神文明建设的双丰收。     

Symbiosis specificity in the legume: rhizobial mutualism

Legume plants are able to engage in root nodule symbiosis with nitrogen-fixing soil bacteria, collectively called rhizobia. This mutualistic association is highly specific, such that each rhizobial species/strain interacts with only a specific group of legumes, and vice versa. Symbiosis specificity can occur at multiple phases of the interaction, ranging from initial bacterial attachment and infection to late nodule development associated with nitrogen fixation. Genetic control of symbiosis specificity is complex, involving fine-tuned signal communication between the symbiotic partners. Here we review our current understanding of the mechanisms used by the host and bacteria to choose their symbiotic partners, with a special focus on the role that the host immunity plays in controlling the specificity of the legume - rhizobial symbiosis.     

Cleaner seas: reducing marine pollution

Reviews in Fish Biology and Fisheries - In the age of the Anthropocene, the ocean has typically been viewed as a sink for pollution. Pollution is varied, ranging from human-made plastics and...     

Dissecting Symbiosis: Developments in Nod Factor Signal Transduction

The interaction between legumes and rhizobial bacteria resultsin the formation of a unique organ, the nodule, on roots ofthe host plant. The nodule has evolved to harbour the bacterialsymbiont and provide conditions appropriate for the fixationof atmospheric nitrogen. Nod factor, generated by rhizobia,is sufficient to activate many of the responses involved inthe initiation of nodule development in the plant. Dissectingthe Nod factor signal transduction pathway has been greatlyaided by the adoption of genetically tractable model legumes.Recent studies have identified a number of genes involved inthis pathway and candidate proteins for the Nod factor receptor.Furthermore, a plethora of cellular responses have been linkedwith Nod factor perception. This Botanical Briefing covers recentadvances in the dissection of Nod factor signal transductionin the plant.Copyright 2001 Annals of Botany Company Review, Nod factor, rhizobia, nodulation, signal transduction