Single stage treatment of saline wastewater with marine bacterial-microalgae consortia in a fixed-bed photobioreactor.

Currently, the treatment of aquaculture-origin effluents is mainly performed through land-based recirculating aquaculture systems (RAS). In this study, we evaluate and introduce a novel immobilized/packed bed bioreactor which uses a synthetic textile as the support medium. A marine microbial consortium was developed on the textile by its inoculation with the microalgae Picochlorum sp. The bioreactor was tested with variable loadings of C and N and showed outstanding performance approaching removal rates up to 95% within a few hours (4-5h) of operation. Pyrosequencing analysis revealed a novel microbial consortium consisting mainly of chitrinomycetes, Pseudomonas sp. and the absence of ß-proteobacteria, which is the Class encompassing autotrophic nitrifiers. Quantitative polymerase chain reaction further confirmed these findings suggesting heterotrophic nitrification and aerobic denitrification as the principal mechanisms of N-removal from the bioreactor. Overall our findings reveal the potential of the AdvanTex System for the treatment of marine aquaculture effluents-COD reduction and N-removal, in a single stage.

Asymptomatic Carotid Surgery Trial-2 (ACST-2): rationale for a randomised clinical trial comparing carotid endarterectomy with carotid artery stenting in patients with asymptomatic carotid artery stenosis.

OBJECTIVES: To compare carotid endarterectomy with carotid artery stenting in the prevention of stroke in patients with asymptomatic carotid stenosis. DESIGN: A large, simple, pragmatic international trial of at least 5000 patients with asymptomatic carotid stenosis in whom intervention is thought to be needed but where there is substantial uncertainty about the appropriate choice of treatment. The trial is designed to fit in easily with normal clinical practice. MATERIALS & METHODS: A short (approximately 2 min) telephone call is made to randomise patients to either carotid endarterectomy (CEA) or stenting (CAS). Follow-up by the collaborator will be at one month after the procedure (simple 1-page form) and by the ACST office for 5-years post-procedure. Data will be analysed on an intention-to-treat basis; main outcomes will be 30-day myocardial infarction, stroke and death, and 5-year stroke rates. In addition, appropriate subgroup analyses will be undertaken, and health economic evaluation will consider procedural and stroke-related healthcare costs and quality of life. CONCLUSION: Collaborators who routinely undertake CEA and CAS are encouraged to participate in ACST-2. This trial, now funded and open for randomisation, will provide important evidence comparing the immediate and long-term safety and efficacy of carotid endarterectomy and stenting in patients with asymptomatic carotid stenosis.

Performance of an innovative FWS constructed wetland in Crete, Greece.

Pompia is an ancient name of a small community in Messara valley, which is the main agricultural area, in central Crete. The constructed wetland in Pompia is a free water surface (FWS) system, for treating the wastewater of the local community of 1,200 p.e. That wastewater treatment plant (WWTP) is a pilot plant but it is simple, safe, innovative, and environmentally friendly. The WWTP was funded by the Region of Crete. The Eastern Crete Development Organization was responsible for the design, supervision, management, and initial operation. The project was completed in August 1999, and has been under operation since then. The effluent is considered to be equivalent to tertiary treated municipal wastewater, and it will be used to irrigate olive orchards. The general sense for a visitor is that the FWS system operates like a natural marsh and a habitat of birds and wild animals. In addition, very high removal rates for BOD5, COD, TSS, TKN, TP, TC, and FC have been obtained.

Varicose veins: loss of release of vascular endothelial growth factor and reduced plasma nitric oxide.

OBJECTIVES: To examine the release of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in primary varicose veins (VVs) and normal vein controls following experimentally-induced venous stasis. DESIGN, MATERIALS AND METHODS: Patients with primary VVs (n=21) and control subjects (n=11) were rested supine for 15 min. Blood was collected from both an arm and foot vein. A below-knee cuff was applied and inflated to 90-95 mmHg for 10 min (to prompt venous stasis). Further blood samples were collected from the foot vein. Levels of plasma VEGF and NO were analysed. RESULTS: In control subjects, application of the cuff increased levels of plasma VEGF in the foot (p<0.025). In contrast, in patients with VVs, there was little or no change in these levels of plasma VEGF. Cuff application had little effect on levels of plasma NO in either controls, or those with VVs. When compared to controls however, the levels of plasma NO in all samples with VVs (arm, or foot before, or after, cuff application) were reduced (all, p<0.05). CONCLUSIONS: Loss of VEGF release with experimentally-induced venous stasis, and reduced levels of plasma NO may suggest a mechanism important in the development of primary VVs.