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Hydrous ferric oxide (here termed 'ochre') sludge, an abundant waste product produced from the treatment of acid mine drainage (AMD), was used in this study for the removal of phosphorus (in the form of phosphate ions) from contaminated waters. The phosphorus uptake capacities of both raw and pelletized AMD solids were compared using batch and column tests. Addition of a cement binder to the AMD solids during pellet production led to significantly increased P-loading of the resultant solids compared to the raw sludge. Additionally, the pellets were found to continue to remove P in tests up to 7 d in duration whereas the unbound AMD sludge appeared to approach equilibrium with phosphate solution after approximately 60 min of contact time. In line with previous studies P uptake by the AMD solids was found to be primarily via adsorption. By contrast calcium phosphate precipitation was found to be the dominant removal mechanism for the cement-bound ochre pellets with a relatively small proportion of removal attributable to the AMD solids. SEM-EDX analysis of the surface of used pellets showed a Ca:P molar ratio close to that of hydroxyapatite (HAP). Continuous column tests on these pellets showed a rapid decrease in P removal capacity by the pellets over time, attributable to the formation of a passivating HAP surface layer., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Actin has a pivotal function in hyphal morphogenesis in filamentous fungi, but it is not certain whether its function is equivalent to that of a morphogen, or if it is simply part of a mechanism that executes orders given by another regulatory entity. To address this question we selected for cytochalasin A resistance and isolated act1, the first actin mutant in Neurospora crassa. This mutant branches apically and shows an altered distribution of actin at the tip. Based on the properties of this mutant, we propose a model of tip growth and branching in which actin effects tip growth by regulating the rate of vesicle flow from proximal to distal regions of a hypha, thereby controlling the tip-high gradient of cytoplasmic calcium. The actin-controlled calcium gradient at the tip is necessary for maintenance of tip growth as well as the dominance of one polarized site at the hyphal tip. The phenotype of act1 indicates that actin controls the balance between lateral and apical branching.

There are at least 100 loci encoding products that influence tip growth and branching in Neurospora crassa. The functional relationships between 38 of these loci were examined by an analysis of gene interaction in double mutants. A complex range of interactions was revealed. These have been grouped into full and partial epistasis, costasis, novel phenotypes, and synthetic lethality and sublethality. Epistasis was used to construct the simplest "pathway" that accommodated the results; this pathway was Y-shaped. If synthetic sublethality is interpreted to reflect mutations in the same pathway, the sublethal connections are compatible with the chart of epistasis. The gene interactions discovered represent candidates for future cell and molecular studies on the interaction of gene products in the control of tip growth and branching.

Waste is never consistent. Different areas use different materials, which give rise to waste streams that can vary widely in composition. With the increasing pressure on landfill operators and local governments over the amount and type of waste going to landfill, moves have to be taken to reduce, divert and recover materials. To undertake this function it is necessary to identify the composition of the waste stream. This paper contains the results of a household waste analysis conducted in a typical unitary authority of South Wales, a traditional industrial community. The waste analysis was conducted to determine whether there was a connection between an area's socio-economic standing and the quantities of waste produced. A selection of three different household categories were chosen, as described by the UK's ACORN geodemographical system. The three areas chosen were terracedd, council and semi-detached properties and were selected as they were the most dominant and easily recognised types of dwellings found in the study area. The results of the full waste analysis have been compared against a number of previous household waste characterisation studies.

In N. crassa and N. intermedia, the kalilo plasmid triggers senescence by insertion into mitochondrial DNA. To investigate the cell death pathway induced by this plasmid, juvenile and senescent subcultures of several senescent strains were examined by light and transmission electron microscopy, and at the DNA level. There were no signs of apoptotic events, such as shrinkage of the cytoplasm away from the cell wall, apoptotic bodies, internucleosomal DNA fragmentation or condensation of the cytoplasm while retaining mitochondria and endomembrane structure. Instead, swollen mitochondria lacking cristae and containing amorphous inclusions, and disruption of nuclear and mitochondrial membranes indicated a necrotic mode of cell death.

This paper reviews the volatile nature of the price of recycled metals over the past decade and examines legislative and fiscal drivers that have affected the industry. Results from this study have shown that the UK scrap metals markets are presently seeing some of the lowest scrap prices for nearly a decade for both ferrous and non-ferrous metals, in many cases halving in value in less than a year. Scrap metals and other recycled materials prices were high in 1994-96, which have since fallen back to more traditional low levels. World recessions and the steady decline of the UK manufacturing and engineering sectors have effected prices. With tougher new Government legislation, such as the Climate Change Levy and the proposed End of Life Vehicles Directive, small and medium sized scrap merchants are finding it increasingly difficult to compete.