Maternal Responses and Adaptive Changes to Environmental Stress via Chronic Nanomaterial Exposure: Differences in Inter and Transgenerational Interclonal Broods of Daphnia magna

There is increasing recognition that environmental nano-biological interactions in model species, and the resulting effects on progeny, are of paramount importance for nanomaterial (NM) risk assessment. In this work, Daphnia magna F0 mothers were exposed to a range of silver and titanium dioxide NMs. The key biological life history traits (survival, growth and reproduction) of the F1 intergenerations, at the first (F1B1), third (F1B3) and fifth (F1B5) broods, were investigated. Furthermore, the F1 germlines of each of the three broods were investigated over 3 more generations (up to 25 days each) in continuous or removed-from NM exposure, to identify how the length of maternal exposure affects the resulting clonal broods. Our results show how daphnids respond to NM-induced stress, and how the maternal effects show trade-offs between growth, reproduction and survivorship. The F1B1 (and following germline) had the shortest F0 maternal exposure times to the NMs, and thus were the most sensitive showing reduced size and reproductive output. The F1B3 generation had a sub-chronic maternal exposure, whereas the F1B5 generation suffered chronic maternal exposure where (in most cases) the most compensatory adaptive effects were displayed in response to the prolonged NM exposure, including enhanced neonate output and reduced gene expression. Transgenerational responses of multiple germlines showed a direct link with maternal exposure time to ‘sub-lethal’ effect concentrations of NMs (identified from standard OECDs acute toxicity tests which chronically presented as lethal) including increased survival and production of males in the F1B3 and G1B5 germlines. This information may help to fine-tune environmental risk assessments of NMs and prediction of their impacts on environmental ecology.     

A survey of dynamic parameter setting methods for nature-inspired swarm intelligence algorithms

Neural Computing and Applications - Parameter settings for nature-inspired optimization algorithms are essential for their effective performance. Evolutionary algorithms and swarm intelligence...     

Modulators of Macrophage Polarization Influence Healing of the Infarcted Myocardium

To diminish heart failure development after acute myocardial infarction (AMI), several preclinical studies have focused on influencing the inflammatory processes in the healing response post-AMI. The initial purpose of this healing response is to clear cell debris of the injured cardiac tissue and to eventually resolve inflammation and support scar tissue formation. This is a well-balanced reaction. However, excess inflammation can lead to infarct expansion, adverse ventricular remodeling and thereby propagate heart failure development. Different macrophage subtypes are centrally involved in both the promotion and resolution phase of inflammation. Modulation of macrophage subset polarization has been described to greatly affect the quality and outcome of healing after AMI. Therefore, it is of great interest to reveal the process of macrophage polarization to support the development of therapeutic targets. The current review summarizes (pre)clinical studies that demonstrate essential molecules involved in macrophage polarization that can be modulated and influence cardiac healing after AMI.     

Integrated understanding of urban land, groundwater, baseflow and surface-water quality--the City of Birmingham, UK

Integrated understanding of urban land, groundwater (shallow and deep), baseflow and surface-water quality relationships is required for effective urban water-quality management. Chemical quality data from across these media have been collected for the Birmingham (UK) aquifer--River Tame conurbation to assess chemical transport from contaminated land to groundwater to baseflow to surface water. Although metals concentrations were high in soils, low leachability and attenuation caused concentrations in groundwaters and baseflow discharging to surface water to be generally low with only sporadic elevated concentrations attributed to localised point sources. Hydrocarbon VOCs (volatile organic compounds) were similarly absent or at low concentration attributable to their ready natural attenuation. Chlorinated VOCs, however, were widely encountered in groundwater, discharging as baseflow to surface water and impacting surface-water quality. This is attributed to their DNAPL (dense nonaqueous-phase liquid) properties and relative recalcitrance although there was some evidence of biodegradation, albeit insufficient to protect surface water and groundwater abstraction receptors. Some inorganic trends were evident across the various media; nitrate was the most significant quality concern. Generic conclusions are drawn on urban water-quality management and the need for risk-based management strategies to optimise use of urban, sporadically contaminated groundwater in conjunction with surface water highlighted.     

Chlorination of model drinking water biofilm: implications for growth and organic carbon removal

The influence of chlorine on biofilm in low organic carbon environments typical of drinking water or industrial process water was examined by comparing biomass and kinetic parameters for biofilm growth in a chlorinated reactor to those in a non-chlorinated control. Mixed-population heterotrophic biofilms were developed in rotating annular reactors under low concentration, carbon-limited conditions (< 2 mg/L as carbon) using three substrate groups (amino acids, carbohydrates and humic substances). Reactors were operated in parallel under identical conditions with the exception that chlorine was added to one reactor at a dose sufficient to maintain a free chlorine residual of 0.09-0.15 mg/L in the effluent. The presence of free chlorine resulted in development of less biofilm biomass compared to the control for all substrates investigated. However, specific growth and organic carbon removal rates were on the average five times greater for chlorinated biofilm compared to the control. Observed yield values were less for chlorinated biofilm. Although chlorinated biofilm's specific organic carbon removal rate was high, the low observed yield indicated organic carbon was being utilized for purposes other than creating new cell biomass. The impacts of free chlorine on mixed-population biofilms in low-nutrient environments were different depending upon the available substrate. Biofilms grown using amino acids exhibited the least difference between control and chlorinated kinetic parameters; biofilm grown using carbohydrates had the greatest differences. These findings are particularly relevant to the fundamental kinetic parameters used in models of biofilm growth in piping systems that distribute chlorinated, low-carbon-concentration water.     

Effect of spatial variability on arma modelling of ground motion

The Autoregressive-Moving Average (ARMA) process is an efficient method for describing ground motion through a small number of parameters. By relating these parameters to physical variables, it is possible to reasonably predict the ground motion of a site where no strong motion data has been recorded. In this paper, the effects of spatial variability on modelling strong ground motion with ARMA processes are investigated. The cross-correlation between variance stabilized series is analyzed for sites located in Mexico City. Also, the correlation and distribution of modelling parameters in the Smart-1 dense array is investigated.     

Detoxification of seawater used for gas scrubbing in the steel industry

Cyanide ion present in seawater after scrubbing blast furnace and coke ovens gases can be removed by sedimentation of hexacyanoferrate complexes followed by oxidation of residual cyanide with Caro's acid. Zinc ion is removed at the same time by adsorption on the hexacyanoferrate/hydrous ferric oxide precipitate.Sulphide is precipitated as ferrous sulphide, then oxidised by atmospheric oxygen. At 25°C and using an Fe/CN ratio of 1·00, initial concentrations of 50 mg l⁻¹ of CN⁻ and 10 mg l⁻¹ of Zn²⁺ in seawater are reduced to 5–7 mg l⁻¹ and 0·1 mg l⁻¹. Subsequent treatment with H₂SO₅/CN = 1·2 reduces the [CN⁻] to 0·1 mg l⁻¹.Treatment of a combined blast furnace/coke ovens effluent ([CN⁻] = 24 mgl⁻¹, [Zn²⁺] = 4·0 mgl⁻¹) with Fe/CN = 1·5 reduced [CN⁻] to 0·2 mg l⁻¹ and [Zn²⁺] to <0·1 mgl⁻¹. Subsequent treatment with H₂SO₅/CN = 2·0 reduced [CN⁻] to 0·2 mg l⁻¹. The process operates best in the pH range 7–9 and so is not affected by the buffer characteristics of seawater.     

LEARNING TO FORGET: Architectural Recreation,Spatial Visualization and Imaging the Unseen

Children learn through play, through re-creating situations and events. While playing, children forget themselves, time is suspended, and mind, body and emotions work together simultaneously in the child's re-creations. This is a four-dimensional type of space, similar to the intuitive inner space that opens up during the spatial visualization of architectural recreation. The following discusses an architectural pedagogy that teaches students how to forget: how to leave behind the inherent symbolic and logic structures of the rational mind that would have them name things, so that they may develop the abilities of the metaphoric mind to visualize spatially and image the unseen.