Efficacy of different antifouling treatments for seawater cooling systems

In an industrial seawater cooling system, the effects of three different antifouling treatments, viz. sodium hypochlorite (NaClO), aliphatic amines (Mexel1432) and UV radiation, on the characteristics of the fouling formed were evaluated. For this study a portable pilot plant, as a side-stream monitoring system and seawater cooling system, was employed. The pilot plant simulated a power plant steam condenser, having four titanium tubes under different treatment patterns, where fouling progression could be monitored. The nature of the fouling obtained was chiefly inorganic, showing a clear dependence on the antifouling treatment employed. After 72 days the tubes under treatment showed a reduction in the heat transfer resistance (R) of around 70% for NaClO, 48% for aliphatic amines and 55% for UV, with respect to the untreated tube. The use of a logistic model was very useful for predicting the fouling progression and the maximum asymptotic value of the increment in the heat transfer resistance (DRmax). The apparent thermal conductivity (l) of the fouling layer showed a direct relationship with the percentage of organic matter in the collected fouling. The characteristics and mode of action of the different treatments used led to fouling with diverse physicochemical properties

\u3ci\u3eAquastella gen. nov.\u3c/i\u3e: A new genus of saprolegniaceous oomycete rotifer parasites related to \u3ci\u3eAphanomyces\u3c/i\u3e, with unique sporangial outgrowths

The oomycete genus Aquastella is described to accommodate two new species of parasites of rotifers observed in Brooktrout Lake, New York State, USA. Three rotifer species – Keratella taurocephala,Polyarthra vulgaris, and Ploesoma truncatum – were infected, and this is the first report of oomycete infection in these species. Aquastella attenuata was specific to K. taurocephala and Aquastella aciculariswas specific to P. vulgaris and P. truncatum. The occurrence of infections correlated with peak host population densities and rotifers were infected in the upper layers of the water column. Sequencing of 18S rRNA and phylogenetic analysis of both species placed them within the order Saprolegniales, in a clade closely related to Aphanomyces. The Aquastella species were morphologically distinct from other rotifer parasites as the developing sporangia penetrated out through the host body following its death to produce unique tapered outgrowths. Aquastella attenuata produced long, narrow, tapering, finger-like outgrowths, whilst A. acicularis produced shorter, spike-like outgrowths. We hypothesize that the outgrowths serve to deter predation and slow descent in the water column. Spore cleavage was intrasporangial with spore release through exit tubes. Aquastella attenuata produced primary zoospores, whereas A. acicularisreleased spherical primary aplanospores, more typical of other genera in the Aphanomyces clade

Finding the essential : improving conservation monitoring across scales

To account for progress towards conservation targets, monitoring systems should capture not only information on biodiversity but also knowledge on the dynamics of ecological processes and the related effects on human well-being. Protected areas represent complex social-ecological systems with strong human-nature interactions. They are able to provide relevant information about how global and local scale drivers (e.g., climate change, land use change) impact biodiversity and ecosystem services. Here we develop a framework that uses an ecosystem-focused approach to support managers in identifying essential variables in an integrated and scalable approach. We advocate that this approach can complement current essential variable developments, by allowing conservation managers to draw on system-level knowledge and theory of biodiversity and ecosystems to identify locally important variables that meet the local or sub-global needs for conservation data. This requires the development of system narratives and causal diagrams that pinpoints the social-ecological variables that represent the state and drivers of the different components, and their relationships. We describe a scalable framework that builds on system based narratives to describe all system components, the models used to represent them and the data needed. Considering the global distribution of protected areas, with an investment in standards, transparency, and on active data mobilisation strategies for essential variables, these have the potential to be the backbone of global biodiversity monitoring, benefiting countries, biodiversity observation networks and the global biodiversity community

Seasonal dynamics of zebra mussel parasite populations

International audienceThe seasonal dynamics of 8 parasite taxa in zebra mussels Dreissena polymorpha were studied in the Meuse River (NE France) over a 3 yr period. In total, 69.5% of sampled organisms were infected. Among observed parasite species, Ophryoglena spp. and to a lesser extent Rickettsiales-like organisms (RLOs) displayed seasonal dynamics, with lower prevalence during warmer months negatively correlated with gonadal development in the host, water temperature and phytoplankton concentration. Furthermore, this study highlights a positive correlation be tween the prevalence rates of Ophryoglena spp. and RLOs. No temporal variations were ob served for the ciliates Sphenophrya dreissenae and Conchophthirus acuminatus. Concerning trematode infection, no defined seasonal pattern was observed. Thus, for more reliability in future biomonitoring studies involving zebra mussels, it will be important to include the influence of parasites and their temporal dynamics

Anisotropic liquid crystalline epoxy thermoset

The processing of an anisotropic liquid crystalline thermoset formed by p-bis(2,3-epoxypropoxy)-α-methylstilbene (DOMS) and 1-methyl-2,4-diaminobenzene (DAT) with uniformly oriented mesomorphic molecules, and consequently strongly birefringent, is described. The unidirectional alignment of the molecules was achieved during the curing process by external factors such as surface-liquid crystal interactions and/or an applied electric field. The control over the molecular orientation enabled us to produce well oriented highly anisotropic and birefringent epoxy thin films. In this paper, we discuss the formation process and the properties of the anisotropic epoxy network

Highly uniform oriented liquid crystalline thermosets

Curing of mesogenic epoxy monomer p-Bis(2,3-epoxypropoxy)-α-methylstilbene (DOMS) with aromatic amines is discussed. The crossing density is controlled using a mixture of bi- and tetra-functional hardener. The unidirectional alignment of the molecules was achieved during the curing process by external factors such as surface-liquid crystal interactions