The feasibility of using constructed wetlands systems for urban wastewater

Constructed treatment wetlands are used globally to treat stormwater and a variety of wastewater for the effective removal of nutrients and pollutants. This technology is a proven method for water treatment and is gaining greater momentum in its application in Australia. The technology allows for reductions in construction and ongoing capital costs such as energy consumption as is seen in traditional wastewater treatment works. In addition, this technology can reduce the need for chemical dosing treatment of waste water management systems. Treatment wetlands are a passive system capable of treating primary, secondary and tertiary effluent, however, predominantly they have been employed to treat wastewater beyond the secondary level, often referred to as effluent polishing (Kadlec and Knight, 1996). Treatment wetlands are more commonly applied to the treatment of stormwater runoff however are also effective for treating human wastewater, industrial, mining and agricultural effluent. The reuse and reclamation of treated waste water is gaining momentum especially in countries where water is or is becoming more of a scarce and expensive resource but will also provide a benefit in terms of environmental sustainability with respect to the health of our waterways and our water resources in general. Investigation into the feasibility of a passive treatment system was undertaken for a large urban population to determine if civil costs, operational costs and EPA load based license fees have the potential to be reduced. Specifically the comparison of the efficacy of two types of constructed wetland systems was undertaken. A traditional constructed wetland and a floating treatment wetland were compared, as part of the treatment process for municipal wastewater to meet discharge limits and to determine which type of wetland has greater viability with regard to its actual footprint, land availability and also treatment efficiency. The Constructed Wetlands Manual (DLWC, 1998) as well as sizing methodology put forward by Kadlec and Knight (1996) and Reed et al. (1995) were utilised to determine wetland surface area. Floating treatment wetlands appear to be the most feasible option in terms of land footprint and enabling the retrofitting of existing structures, however in terms of treatment efficiency and installation costs have resulted, in this study, not to be a feasible option or alternative to the current wastewater treatment systems for Bathurst Regional Council without further trials and being undertaken both in terms of refining the treatment efficiency and also investigations in how to reduce the capital costs of installing a floating treatment wetland

Immune Priming: Mothering Males Modulate Immunity

SummaryThe transfer of immunity from mother to offspring is widespread in animals. The father’s contribution to this is usually negligible. However, in a sex-role reversed pipefish where fathers do the mothering, fathers make an important immune priming contribution, too

Maximum entropy models for antibody diversity

Recognition of pathogens relies on families of proteins showing great diversity. Here we construct maximum entropy models of the sequence repertoire, building on recent experiments that provide a nearly exhaustive sampling of the IgM sequences in zebrafish. These models are based solely on pairwise correlations between residue positions, but correctly capture the higher order statistical properties of the repertoire. Exploiting the interpretation of these models as statistical physics problems, we make several predictions for the collective properties of the sequence ensemble: the distribution of sequences obeys Zipf's law, the repertoire decomposes into several clusters, and there is a massive restriction of diversity due to the correlations. These predictions are completely inconsistent with models in which amino acid substitutions are made independently at each site, and are in good agreement with the data. Our results suggest that antibody diversity is not limited by the sequences encoded in the genome, and may reflect rapid adaptation to antigenic challenges. This approach should be applicable to the study of the global properties of other protein families

Infection of zebrafish embryos with intracellular bacterial pathogens

Zebrafish (Danio rerio) embryos are increasingly used as a model for studying the function of the vertebrate innate immune system in host-pathogen interactions (1). The major cell types of the innate immune system, macrophages and neutrophils, develop during the first days of embryogenesis prior to the maturation of lymphocytes that are required for adaptive immune responses. The ease of obtaining large numbers of embryos, their accessibility due to external development, the optical transparency of embryonic and larval stages, a wide range of genetic tools, extensive mutant resources and collections of transgenic reporter lines, all add to the versatility of the zebrafish model. Salmonella enterica serovar Typhimurium (S. typhimurium) and Mycobacterium marinum can reside intracellularly in macrophages and are frequently used to study host-pathogen interactions in zebrafish embryos. The infection processes of these two bacterial pathogens are interesting to compare because S. typhimurium infection is acute and lethal within one day, whereas M. marinum infection is chronic and can be imaged up to the larval stage (2, 3). The site of micro-injection of bacteria into the embryo (Figure 1) determines whether the infection will rapidly become systemic or will initially remain localized. A rapid systemic infection can be established by micro-injecting bacteria directly into the blood circulation via the caudal vein at the posterior blood island or via the Duct of Cuvier, a wide circulation channel on the yolk sac connecting the heart to the trunk vasculature. At 1 dpf, when embryos at this stage have phagocytically active macrophages but neutrophils have not yet matured, injecting into the blood island is preferred. For injections at 2-3 dpf, when embryos also have developed functional (myeloperoxidase-producing) neutrophils, the Duct of Cuvier is preferred as the injection site. To study directed migration of myeloid cells towards local infections, bacteria can be injected into the tail muscle, otic vesicle, or hindbrain ventricle (4-6). In addition, the notochord, a structure that appears to be normally inaccessible to myeloid cells, is highly susceptible to local infection (7). A useful alternative for high-throughput applications is the injection of bacteria into the yolk of embryos within the first hours after fertilization (8). Combining fluorescent bacteria and transgenic zebrafish lines with fluorescent macrophages or neutrophils creates ideal circumstances for multi-color imaging of host-pathogen interactions. This video article will describe detailed protocols for intravenous and local infection of zebrafish embryos with S. typhimurium or M. marinum bacteria and for subsequent fluorescence imaging of the interaction with cells of the innate immune system

Effect in supralethally irradiated rats of granulocyte colony- stimulating factor and lisofylline on hematopoietic reconstitution by syngeneic bone marrow or whole organ passenger leukocytes

We have previously shown the existence of migratory hematopoietic stem cells in adult solid organs. This study demonstrates that granulocyte colony- stimulating factor (G-CSF) and lisofylline, a phosphatidic acid inhibitor that suppresses hematopoiesis-inhibiting cytokines, can enhance the engraftment of organ-based hematopoietic stem cells. When syngeneic heart grafts or liver nonparenchymal cells were transplanted into lethally irradiated (9.5 Gy) Lewis rats, complete hematopoietic reconstitution and animal survival were significantly improved by treating the recipient with G- CSF or, to a lesser extent, with lisofylline. Pretreatment of hepatic nonparenchymal cell donors with G-CSF, but not lisofylline, also resulted in striking improvement of recipient survival which was associated with an augmented subpopulation of donor stem cells. The results suggest that these drugs can be used to enhance the chimerism that we postulate to be the basis of organ allograft acceptance

Hydrogen Peroxide in Inflammation: Messenger, Guide, and Assassin

Starting as a model for developmental genetics, embryology, and organogenesis, the zebrafish has become increasingly popular as a model organism for numerous areas of biology and biomedicine over the last decades. Within haematology, this includes studies on blood cell development and function and the intricate regulatory mechanisms within vertebrate immunity. Here, we review recent studies on the immediate mechanisms mounting an inflammatory response by in vivo analyses using the zebrafish. These recently revealed novel roles of the reactive oxygen species hydrogen peroxide that have changed our view on the initiation of a granulocytic inflammatory response

Hydrogen Peroxide in Inflammation : Messenger, Guide, and Assassin

Starting as a model for developmental genetics, embryology, and organogenesis, the zebrafish has become increasingly popular as a model organism for numerous areas of biology and biomedicine over the last decades.Within haematology, this includes studies on blood cell development and function and the intricate regulatory mechanisms within vertebrate immunity. Here, we review recent studies on the immediate mechanisms mounting an inflammatory response by in vivo analyses using the zebrafish. These recently revealed novel roles of the reactive oxygen species hydrogen peroxide that have changed our view on the initiation of a granulocytic inflammatory response

Myeloid Growth Factors Promote Resistance to Mycobacterial Infection by Curtailing Granuloma Necrosis through Macrophage Replenishment.

The mycobacterial ESX-1 virulence locus accelerates macrophage recruitment to the forming tuberculous granuloma. Newly recruited macrophages phagocytose previously infected apoptotic macrophages to become new bacterial growth niches. Granuloma macrophages can then necrose, releasing mycobacteria into the extracellular milieu, which potentiates their growth even further. Using zebrafish with genetic or pharmacologically induced macrophage deficiencies, we find that global macrophage deficits increase susceptibility to mycobacterial infection by accelerating granuloma necrosis. This is because reduction in the macrophage supply below a critical threshold decreases granuloma macrophage replenishment to the point where apoptotic infected macrophages, failing to get engulfed, necrose. Reducing macrophage demand by removing bacterial ESX-1 offsets the susceptibility of macrophage deficits. Conversely, increasing macrophage supply in wild-type fish by overexpressing myeloid growth factors induces resistance by curtailing necrosis. These findings may explain the susceptibility of humans with mononuclear cytopenias to mycobacterial infections and highlight the therapeutic potential of myeloid growth factors in tuberculosis.This work was funded by grants from the National Institutes of Health (T32-AI055396, A.J.P.; A154503 and A136396, L.R.) and the National Health and Medical Research Council (637394, 1044754, and 1069284, G.J.L.), a post-doctoral fellowship from the Taiwan National Science Council (NSC97-2917-I-564-109, C-T.Y.), and an Australian Postgraduate Award and Walter and Eliza Hall Institute of Medical Research Edith Moffatt Scholarship (F.E.). The Australian Regenerative Medicine Institute is supported by funds from the State Government of Victoria and the Australian Federal Government. L.R. is a recipient of the NIH Director’s Pioneer Award and a Wellcome Trust Principal Research Fellowship.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.chom.2015.06.00

Bcl3 prevents acute inflammatory lung injury in mice by restraining emergency granulopoiesis

Granulocytes are pivotal regulators of tissue injury. However, the transcriptional mechanisms that regulate granulopoiesis under inflammatory conditions are poorly understood. Here we show that the transcriptional coregulator B cell leukemia/lymphoma 3 (Bcl3) limits granulopoiesis under emergency (i.e., inflammatory) conditions, but not homeostatic conditions. Treatment of mouse myeloid progenitors with G-CSF — serum concentrations of which rise under inflammatory conditions — rapidly increased Bcl3 transcript accumulation in a STAT3-dependent manner. Bcl3-deficient myeloid progenitors demonstrated an enhanced capacity to proliferate and differentiate into granulocytes following G-CSF stimulation, whereas the accumulation of Bcl3 protein attenuated granulopoiesis in an NF-κB p50–dependent manner. In a clinically relevant model of transplant-mediated lung ischemia reperfusion injury, expression of Bcl3 in recipients inhibited emergency granulopoiesis and limited acute graft damage. These data demonstrate a critical role for Bcl3 in regulating emergency granulopoiesis and suggest that targeting the differentiation of myeloid progenitors may be a therapeutic strategy for preventing inflammatory lung injury