Land application of lime amended biosolids.

Increased nutrient levels in inland waterways have led to algal blooms and eutrophication in many agricultural regions. To ensure fertiliser inputs are managed more effectively, the source of contamination needs to be tracked and identified. Point sources could include inorganic fertilisers, livestock excreta, or more recently biosolids. The presence of faecal indicator microorganisms has been widely used to identify the presence of faeces, however, these methods cannot distinguish between human and animals samples. This study investigated PCR amplification as a molecular method to distinguish biosolids from livestock faeces of biosolids, cattle, sheep, poultry and kangaroo. This was achieved using published priming sequences and restriction site profiling of amplified DNA across the 16S rRNA gene of anaerobic gastrointestinal bacteria Bacteroides spp and Bifidobacteria spp. Preliminary investigation showed that of the three Bacteroides spp primer pairs investigated, two were useful for cow faecal material; though at lower annealing temperatures were also applicable to biosolids and sheep faecal material. The third primer pair was specific only for biosolids. All three primer pairs were unable to PCR-amplify Bacteroides spp sequences in faecal material of kangaroo. Of the three Bifidobacteria spp primer pairs, one was useful for sheep faecal material; though at lower annealing temperature was also applicable to biosolids and cow and kangaroo faecal material. The Bifidobacterium angulatum specific primer pair enabled the PCR detection of anaerobes only in biosolids and faecal material of kangaroo. The third, a Bifidobacterium catenulatum specific primer pair was suitable for faecal material of cow and at lower annealing temperatures was also applicable to the sample from sheep. Varying degrees of success were observed in faecal material from other animals. Generally, biosolids tested positive for Bacteroides and Bfidobacteria with all primers except for those specific for B. angulatum. For some primer sets, PCR amplification alone could not differentiate biosolids from other faecal samples. The serial dilution of water contaminated by a range of livestock excreta and biosolids is being examined further to enable the sensitivity of this method to be applied in the field.Soil acidification is an increasing problem throughout many agricultural regions in Australia typically on lighter-textured soils that have a low buffering capacity to changes in soil pH and/or that may be naturally acidic. Crops and pastures grown on acidic soils are subject to problems such as aluminium toxicity (particularly in the subsoil), nodulation failure in legumes and a reduced availability of some nutrients. Lime and dolomite are products that are commonly applied to neutralise soil acidity and improve plant productivity with application rates often determined by their neutralising value and particle size of the product, and the pH buffering capacity (lime requirement) of the soil. To investigate the effect of lime amended biosolids (LAB) as a product for neutralising soil acidity and for improving crop growth, four rates of LAB (0, 5, 10 and 15 t DS/ha) and four equivalent rates of lime product (0, 2.3, 4.6 and 6.7 t/ha) were applied to an acidic red/brown sandy loam in the central wheatbelt of Western Australia. In addition, one rate of dewatered biosolids cake (DBC) at 7 t DS/ha was included to enable comparison to be made to this product. The experiment was conducted over three years and sown to wheat (Triticum aestivum), canola (Brassica napus) and then wheat in 2005, 2006 and 2007, respectively. Plants were sampled at 8 weeks and at harvest to determine the effect of LAB, lime and DBC on crop growth, nutrient uptake and grain yield. Samples of surface soil (0-10 cm) were collected and analysed at harvest for pH and major nutrients. Soil pH increased significantly with increasing rates of LAB or lime at the end of the first year, with similar values recorded between equivalent values of lime product. There was no significant change in soil pH following the addition of the DBC treatment. No further changes in soil pH had occurred by the end of the second year. The growth of both wheat and canola in the first two years was affected to a greater extent by nutrients (typically nitrogen) in the LAB than by the reduction in soil acidity. Measurements on wheat yield in the third year of the experiment and changes in soil pH in the surface (0-10 cm) and subsoil (10-20 cm) will provide further information as to the long term effects of LAB in agriculture and allow recommendations to be made regarding best practise land application rates

A recurrent neural network with ever changing synapses

A recurrent neural network with noisy input is studied analytically, on the basis of a Discrete Time Master Equation. The latter is derived from a biologically realizable learning rule for the weights of the connections. In a numerical study it is found that the fixed points of the dynamics of the net are time dependent, implying that the representation in the brain of a fixed piece of information (e.g., a word to be recognized) is not fixed in time.Comment: 17 pages, LaTeX, 4 figure

The XY Spin-Glass with Slow Dynamic Couplings

We investigate an XY spin-glass model in which both spins and couplings evolve in time: the spins change rapidly according to Glauber-type rules, whereas the couplings evolve slowly with a dynamics involving spin correlations and Gaussian disorder. For large times the model can be solved using replica theory. In contrast to the XY-model with static disordered couplings, solving the present model requires two levels of replicas, one for the spins and one for the couplings. Relevant order parameters are defined and a phase diagram is obtained upon making the replica-symmetric Ansatz. The system exhibits two different spin-glass phases, with distinct de Almeida-Thouless lines, marking continuous replica-symmetry breaking: one describing freezing of the spins only, and one describing freezing of both spins and couplings.Comment: 7 pages, Latex, 3 eps figure

Hierarchical Self-Programming in Recurrent Neural Networks

We study self-programming in recurrent neural networks where both neurons (the `processors') and synaptic interactions (`the programme') evolve in time simultaneously, according to specific coupled stochastic equations. The interactions are divided into a hierarchy of $L$ groups with adiabatically separated and monotonically increasing time-scales, representing sub-routines of the system programme of decreasing volatility. We solve this model in equilibrium, assuming ergodicity at every level, and find as our replica-symmetric solution a formalism with a structure similar but not identical to Parisi's $L$-step replica symmetry breaking scheme. Apart from differences in details of the equations (due to the fact that here interactions, rather than spins, are grouped into clusters with different time-scales), in the present model the block sizes $m_i$ of the emerging ultrametric solution are not restricted to the interval $[0,1]$, but are independent control parameters, defined in terms of the noise strengths of the various levels in the hierarchy, which can take any value in [0,\infty\ket. This is shown to lead to extremely rich phase diagrams, with an abundance of first-order transitions especially when the level of stochasticity in the interaction dynamics is chosen to be low.Comment: 53 pages, 19 figures. Submitted to J. Phys.

Stochastic learning in a neural network with adapting synapses

We consider a neural network with adapting synapses whose dynamics can be analitically computed. The model is made of $N$ neurons and each of them is connected to $K$ input neurons chosen at random in the network. The synapses are $n$-states variables which evolve in time according to Stochastic Learning rules; a parallel stochastic dynamics is assumed for neurons. Since the network maintains the same dynamics whether it is engaged in computation or in learning new memories, a very low probability of synaptic transitions is assumed. In the limit $N\to\infty$ with $K$ large and finite, the correlations of neurons and synapses can be neglected and the dynamics can be analitically calculated by flow equations for the macroscopic parameters of the system.Comment: 25 pages, LaTeX fil

Benefits of using biosolid nutrients in Australian agriculture - a national perspective.

Increased nutrient levels in inland waterways have led to algal blooms and eutrophication in many agricultural regions. To ensure fertiliser inputs are managed more effectively, the source of contamination needs to be tracked and identified. Point sources could include inorganic fertilisers, livestock excreta, or more recently biosolids. The presence of faecal indicator microorganisms has been widely used to identify the presence of faeces, however, these methods cannot distinguish between human and animals samples. This study investigated PCR amplification as a molecular method to distinguish biosolids from livestock faeces of biosolids, cattle, sheep, poultry and kangaroo. This was achieved using published priming sequences and restriction site profiling of amplified DNA across the 16S rRNA gene of anaerobic gastrointestinal bacteria Bacteroides spp and Bifidobacteria spp. Preliminary investigation showed that of the three Bacteroides spp primer pairs investigated, two were useful for cow faecal material; though at lower annealing temperatures were also applicable to biosolids and sheep faecal material. The third primer pair was specific only for biosolids. All three primer pairs were unable to PCR-amplify Bacteroides spp sequences in faecal material of kangaroo. Of the three Bifidobacteria spp primer pairs, one was useful for sheep faecal material; though at lower annealing temperature was also applicable to biosolids and cow and kangaroo faecal material. The Bifidobacterium angulatum specific primer pair enabled the PCR detection of anaerobes only in biosolids and faecal material of kangaroo. The third, a Bifidobacterium catenulatum specific primer pair was suitable for faecal material of cow and at lower annealing temperatures was also applicable to the sample from sheep. Varying degrees of success were observed in faecal material from other animals. Generally, biosolids tested positive for Bacteroides and Bfidobacteria with all primers except for those specific for B. angulatum. For some primer sets, PCR amplification alone could not differentiate biosolids from other faecal samples. The serial dilution of water contaminated by a range of livestock excreta and biosolids is being examined further to enable the sensitivity of this method to be applied in the field.Soil acidification is an increasing problem throughout many agricultural regions in Australia typically on lighter-textured soils that have a low buffering capacity to changes in soil pH and/or that may be naturally acidic. Crops and pastures grown on acidic soils are subject to problems such as aluminium toxicity (particularly in the subsoil), nodulation failure in legumes and a reduced availability of some nutrients. Lime and dolomite are products that are commonly applied to neutralise soil acidity and improve plant productivity with application rates often determined by their neutralising value and particle size of the product, and the pH buffering capacity (lime requirement) of the soil. To investigate the effect of lime amended biosolids (LAB) as a product for neutralising soil acidity and for improving crop growth, four rates of LAB (0, 5, 10 and 15 t DS/ha) and four equivalent rates of lime product (0, 2.3, 4.6 and 6.7 t/ha) were applied to an acidic red/brown sandy loam in the central wheatbelt of Western Australia. In addition, one rate of dewatered biosolids cake (DBC) at 7 t DS/ha was included to enable comparison to be made to this product. The experiment was conducted over three years and sown to wheat (Triticum aestivum), canola (Brassica napus) and then wheat in 2005, 2006 and 2007, respectively. Plants were sampled at 8 weeks and at harvest to determine the effect of LAB, lime and DBC on crop growth, nutrient uptake and grain yield. Samples of surface soil (0-10 cm) were collected and analysed at harvest for pH and major nutrients. Soil pH increased significantly with increasing rates of LAB or lime at the end of the first year, with similar values recorded between equivalent values of lime product. There was no significant change in soil pH following the addition of the DBC treatment. No further changes in soil pH had occurred by the end of the second year. The growth of both wheat and canola in the first two years was affected to a greater extent by nutrients (typically nitrogen) in the LAB than by the reduction in soil acidity. Measurements on wheat yield in the third year of the experiment and changes in soil pH in the surface (0-10 cm) and subsoil (10-20 cm) will provide further information as to the long term effects of LAB in agriculture and allow recommendations to be made regarding best practise land application rates

Modelling the toxicity of copper and zinc to wheat and other crops and incorporation of the results into a proposed framework to derive biosolids guidelines

The application of biosolids to land can have both beneficial and detrimental environmentaleffects. The positive effects can arise from nutrients and organic carbon in the biosolids whilethe negative effects generally arise because of the contamination associated with biosolids(e.g. Broos et al., 2006; Heemsbergen et al., 2006; McLaughlin et al., 2006) but can also arisedue to excessive ammonia (Whatmuff et al., 2006). Therefore, any regulatory guidelinesdeveloped to manage the land application of biosolids must be able to enhance the beneficialeffects and minimise the deleterious effects

Effects of biosolids application on pasture and grape vines in south-eastern Australia

Biosolids were applied to a pasture and a vineyard in south-eastern Australia. At both sites, soil Cd, Cu, and Zn concentrations linearly increased with biosolids application rates although not to the extent of exceeding soil quality guidelines. Biosolids marginally increased soil C and N concentrations at the pasture site but significantly increased P concentrations. With lower overall soil fertility at the vineyard, biosolids increased C, N, and P concentrations. At neither site did biosolids application affect soil microbial endpoints. Biosolids increased pasture production compared to the unfertilised control but had little effect on grape production or quality. Interestingly, over the 3-year trial, there was no difference in pasture production between the biosolids treated plots and plots receiving inorganic fertiliser. These results suggest that biosolids could be used as a fertiliser to stimulate pasture production and as a soil conditioner to improve vineyard soils in this regio

Anomalous f-electron Hall Effect in the Heavy-Fermion System CeTIn5_{5} (T = Co, Ir, or Rh)

The in-plane Hall coefficient $R_{H}(T)$ of CeRhIn$_{5}$, CeIrIn$_{5}$, and CeCoIn$_{5}$ and their respective non-magnetic lanthanum analogs are reported in fields to 90 kOe and at temperatures from 2 K to 325 K. $R_{H}(T)$ is negative, field-independent, and dominated by skew-scattering above $\sim$ 50 K in the Ce compounds. $R_{H}(H \to 0)$ becomes increasingly negative below 50 K and varies with temperature in a manner that is inconsistent with skew scattering. Field-dependent measurements show that the low-T anomaly is strongly suppressed when the applied field is increased to 90 kOe. Measurements on LaRhIn$_{5}$, LaIrIn$_{5}$, and LaCoIn$_{5}$ indicate that the same anomalous temperature dependence is present in the Hall coefficient of these non-magnetic analogs, albeit with a reduced amplitude and no field dependence. Hall angle ($\theta_{H}$) measurements find that the ratio $\rho_{xx}/\rho_{xy}=\cot(\theta_{H})$ varies as $T^{2}$ below 20 K for all three Ce-115 compounds. The Hall angle of the La-115 compounds follow this T-dependence as well. These data suggest that the electronic-structure contribution dominates the Hall effect in the 115 compounds, with $f$-electron and Kondo interactions acting to magnify the influence of the underlying complex band structure. This is in stark contrast to the situation in most $4f$ and $5f$ heavy-fermion compounds where the normal carrier contribution to the Hall effect provides only a small, T-independent background to $R_{H}.$Comment: 23 pages and 8 figure

No Scalar Hair Theorem for a Charged Spherical Black Hole

This paper consolidates noscalar hair theorem for a charged spherically symmetric black hole in four dimension in general relativity as well as in all scalar tensor theories, both minimally and nonminimally coupled, when the effective Newtonian constant of gravity is positive. However, there is an exception when the matter field itself is coupled to the scalar field, such as in dilaton gravity.Comment: 13 pages, Latex format, some minor corrections are made, accepted for publication in Physical Review