Differentiation of biosolids from animal faecal material using the 16s ribosomal RNA genetic markers of gastrointestinal anaerobic bacteria

Recombinant DNA techniques were evaluated for their usefulness in distinguishing biosolids from faecal material of cow, kangaroo and sheep. It involved PCR amplification 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. Of the three Bacteroides spp primer pairs, 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 not able 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 in 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. For some primer sets, PCR amplification alone could not differentiate biosolids from other faecal samples. However, this could be resolved by digesting amplified DNA with the appropriate restriction enzymes. Overall, our evaluations show that recombinant DNA techniques have the potential to distinguish biosolids from other sources of faecal material, including that from kangaroo

Biosolids: Black gold in Western Australia

Of the three major wastewater treatment plants in the capital city of Perth, Western Australia, two produce dewatered biosolids cake (DBC) and the third produces lime-amended biosolids (LAB). The total production of both DBC and LAB in the 2004/2005-year was approximately 20,000 tonnes dry solids (t DS) and is increasing at a growth rate of 4% yr-1. The demand for Perth's biosolids as a low-grade fertiliser has outweighed supply and has achieved an average of 94% beneficial use for the past four years. The use of biosolids in Western Australia is strictly regulated by the 'Western Australian Guidelines for Direct Land Application of Biosolids and Biosolids Products 2002' (DEP et al. 2002). The three major users of biosolids in Western Australia include agriculture, forestry and composting accounting for 74%, 5% and 17% of the total biosolids production, respectively. Within the agricultural sector, the application of DBC commenced in 1996, mostly to wheat and canola crops in a dryland farming system. Local farmers have often referred to the biosolids as 'black gold' due to improvement in their crop yield and income following application. In forestry, biosolids research was commenced in 1998 on a 17 year-old pine plantation on the Swan Coastal Plain. Tree growth has improved significantly following the application of biosolids compared with inorganic fertiliser application, with no detrimental impact on groundwater quality. The composting of biosolids with other materials for domestic use and bagging has been practiced for more than 17 years.This paper summarises the evolution and current use of biosolids in Western Australia and highlights the main research programs instigated by the Water Corporation to ensure that Perth's biosolids are used beneficially and safely in the environment. Research has concentrated mostly on plant and tree nutrient uptake, particularly nitrogen and phosphorus, heavy metals, composting of biosolids, flies and pathogens. Much of the research data has been collected within the Australian National Biosolids Research Project (NBRP)

Small bowel malignant melanoma presenting as a perforated jejunal diverticulum: a case report and literature review.

Although usually harmless and asymptomatic, jejuno-ileal diverticulae are associated with various non-specific gastrointestinal symptoms, and rarely cause surgical emergencies. This case report describes the presentation and management of a patient with an acute abdomen, whose jejunal diverticulum was perforated. Unexpectedly, histopathological assessment demonstrated malignant melanoma lining the diverticulum. Whether this was primary or metastatic is discussed, together with a synopsis of the literature on small bowel diverticulae

Taste changes after bariatric surgery: a systematic review

BACKGROUND: Alterations in taste perception and preferences may contribute to dietary changes and subsequent weight loss following bariatric surgery. METHODS: A systematic search was performed to identify all articles investigating gustation, olfaction, and sensory perception in both animal and human studies following bariatric procedures. RESULTS: Two hundred fifty-five articles were identified after database searches, bibliography inclusions and deduplication. Sixty-one articles were included. These articles provide evidence supporting changes in taste perception and hedonic taste following bariatric procedures. Taste sensitivity to sweet and fatty stimuli appears to increase post-operatively. Additionally, patients also have a reduced hedonic response to these stimuli. CONCLUSIONS: Available evidence suggests that there is a change in taste perception following bariatric procedures, which may contribute to long-term maintenance of weight loss following surgery

Monitoring of waterways for evidence of faecal contamination from biosolids using DNA techniques.

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

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

Land application of sewage sludge (biosolids) in Australia: risks to the environment and food crops

Australia is a large exporter of agricultural products, with producers responsible for a range of quality assurance programs to ensure that food crops are free from various contaminants of detriment to human health. Large volumes of treated sewage sludge (biosolids), although low by world standards, are increasingly being recycled to land, primarily to replace plant nutrients and to improve soil properties; they are used in agriculture, forestry, and composted. The Australian National Biosolids Research Program (NBRP) has linked researchers to a collective goal to investigate nutrients and benchmark safe concentrations of metals nationally using a common methodology, with various other research programs conducted in a number of states specific to regional problems and priorities. The use of biosolids in Australia is strictly regulated by state guidelines, some of which are under review following recent research outcomes. Communication and research between the water industry, regulators and researchers specific to the regulation of biosolids is further enhanced by the Australian and New Zealand Biosolids Partnership (ANZBP).This paper summarises the major issues and constraints related to biosolids use in Australia using specific case examples from Western Australia, a member of the Australian NBRP, and highlights several research projects conducted over the last decade to ensure that biosolids are used beneficially and safely in the environment. Attention is given to research relating to plant nutrient uptake, particularly nitrogen and phosphorus (including that of reduced phosphorus uptake in alum sludge-amended soil); the risk of heavy metal uptake by plants, specifically cadmium, copper and zinc; the risk of pathogen contamination in soil and grain products; change to soil pH (particularly following lime-amended biosolids); and the monitoring of faecal contamination by biosolids in waterbodies using DNA techniques. Examples of products that are currently produced in Western Australia from sewage sludge include mesophilic anaerobically digested and dewatered biosolids cake, lime-amended biosolids, alum sludge and compost

Cortical activity reduction with stimulus repetition: A whole-head MEG analysis

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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

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.