An overview of land application of pig effluent-P using soil P chemistry and mass balance calculations.

Attention is directed at land application of piggery effluent (containing urine, faeces, water, and wasted feed) as a potential source of water resource contamination with phosphorus (P). This paper summarises P-related properties of soil from 0-0.05 m depth at 11 piggery effluent application sites, in order to explore the impact that effluent application has had on the potential for run-off transport of P. The sites investigated were situated on Alfisol, Mollisol, Vertisol, and Spodosol soils in areas that received effluent for 1.5-30 years (estimated effluent-P applications of 100-310000 kg P/ha in total). Total (PT), bicarbonate extractable (PB), and soluble P forms were determined for the soil (0-0.05 m) at paired effluent and no-effluent sites, as well as texture, oxalate-extractable Fe and Al, organic carbon, and pH. All forms of soil P at 0-0.05 m depth increased with effluent application (PB at effluent sites was 1.7-15 times that at no-effluent sites) at 10 of the 11 sites. Increases in PB were strongly related to net P applications (regression analysis of log values for 7 sites with complete data sets: 82.6 % of variance accounted for, p <0.01). Effluent irrigation tended to increase the proportion of soil PT in dilute CaCl2-extractable forms (PTC: effluent average 2.0 %; no-effluent average 0.6%). The proportion of PTC in non-molybdate reactive forms (centrifuged supernatant) decreased (no-effluent average, 46.4 %; effluent average, 13.7 %). Anaerobic lagoon effluent did not reliably acidify soil, since no consistent relationship was observed for pH with effluent application. Soil organic carbon was increased in most of the effluent areas relative to the no-effluent areas. The four effluent areas where organic carbon was reduced had undergone intensive cultivation and cropping. Current effluent management at many of the piggeries failed to maximise the potential for waste P recapture. Ten of the case-study effluent application areas have received effluent-P in excess of crop uptake. While this may not represent a significant risk of leaching where sorption retains P, it has increased the risk of transport of P by run-off. Where such sites are close to surface water, run-off P loads should be managed.

Reactivity of Cationic Terminal Borylene Complexes: Novel Mechanisms for Insertion and Metathesis Chemistry Involving Strongly Lewis Acidic Ligand Systems

The reactions of terminal borylene complexes of the type [CpFe(CO)(2)(BNR2)](+) (R = `Pr, Cy) with heteroallenes have been investigated by quantum-chemical methods, in an attempt to explain the experimentally observed product distributions. Reaction with dicyclohexylcarbodiimide (CyNCNCy) gives a bis-insertion product, in which 1 equiv of carbodiimide is assimilated into each of the Fe=B and B=N double bonds to form a spirocyclic boronium system. In contrast, isocyanates (R'NCO, R' = Ph, 2,6-wXy1, CY; XYl = C6H3Me2) react to give isonitrile complexes of the type [CpFe(CO)(2)(CNR')]+, via a net oxygen abstraction (or formal metathesis) process. Both carbodiimide and socyanate substrates are shown to prefer initial attack at the Fe=B bond rather than the B=N bond of the borylene complex. Further mechanistic studies reveal that the carbodiimide reaction ultimately leads to the bis-insertion compounds [CpFe(CO)(2)C(NCy)(2)B(NCY)(2)CNR2](+), rather than to the isonitrile system [CpFe(CO)(2)(CNCy)](+), on the basis of both thermodynamic (product stability) and kinetic considerations (barrier heights). The mechanism of the initial carbodiimide insertion process is unusual in that it involves coordination of the substrate at the (borylene) ligand followed by migration of the metal fragment, rather than a more conventional process: i.e., coordination of the unsaturated substrate at the metal followed by ligand migration. In the case of isocyanate substrates, metathesis products are competitive with those from the insertion pathway. Direct, single-step metathesis reactivity to give products containing a coordinated isonitrile ligand (i.e. [CpFe(CO)(2)(CNR')](+)) is facile if initial coordination of the isocyanate at boron occurs via the oxygen donor (which is kinetically favored); insertion chemistry is feasible when the isocyanate attacks initially via the nitrogen atom. However, even in the latter case, further reaction of the monoinsertion product so formed with excess isocyanate offers a number of facile (low energetic barrier) routes which also generate ['CpFe(CO)(2)(CNR')](+), rather than the bis-insertion product [CpFe(CO)(2)C(NR')(O)B(NR')(O)CNR2](+) (i.e., the direct analogue of the observed products in the carbodiimide reaction).

Use of electronic portal imaging devices for electron treatment verification

This study aims to help broaden the use of electronic portal imaging devices (EPIDs) for pre-treatment patient positioning verification, from photon-beam radiotherapy to photon- and electron-beam radiotherapy, by proposing and testing a method for acquiring clinicallyuseful EPID images of patient anatomy using electron beams, with a view to enabling and encouraging further research in this area. EPID images used in this study were acquired using all available beams from a linac configured to deliver electron beams with nominal energies of 6, 9, 12, 16 and 20 MeV, as well as photon beams with nominal energies of 6 and 10 MV. A widely-available heterogeneous, approximately-humanoid, thorax phantom was used, to provide an indication of the contrast and noise produced when imaging different types of tissue with comparatively realistic thicknesses. The acquired images were automatically calibrated, corrected for the effects of variations in the sensitivity of individual photodiodes, using a flood field image. For electron beam imaging, flood field EPID calibration images were acquired with and without the placement of blocks of water-equivalent plastic (with thicknesses approximately equal to the practical range of electrons in the plastic) placed upstream of the EPID, to filter out the primary electron beam, leaving only the bremsstrahlung photon signal. While the electron beam images acquired using a standard (unfiltered) flood field calibration were observed to be noisy and difficult to interpret, the electron beam images acquired using the filtered flood field calibration showed tissues and bony anatomy with levels of contrast and noise that were similar to the contrast and noise levels seen in the clinically acceptable photon beam EPID images. The best electron beam imaging results (highest contrast, signal-to-noise and contrast-to-noise ratios) were achieved when the images were acquired using the higher energy electron beams (16 and 20 MeV) when the EPID was calibrated using an intermediate (12 MeV) electron beam energy. These results demonstrate the feasibility of acquiring clinically-useful EPID images of patient anatomy using electron beams and suggest important avenues for future investigation, thus enabling and encouraging further research in this area. There is manifest potential for the EPID imaging method proposed in this work to lead to the clinical use of electron beam imaging for geometric verification of electron treatments in the future.

Understanding how axial loads on the spine influence segmental biomechanics for idiopathic scoliosis patients: A magnetic resonance imaging study

Background Segmental biomechanics of the scoliotic spine are important since the overall spinal deformity is comprised of the cumulative coronal and axial rotations of individual joints. This study investigates the coronal plane segmental biomechanics for adolescent idiopathic scoliosis patients in response to physiologically relevant axial compression. Methods Individual spinal joint compliance in the coronal plane was measured for a series of 15 idiopathic scoliosis patients using axially loaded magnetic resonance imaging. Each patient was first imaged in the supine position with no axial load, and then again following application of an axial compressive load. Coronal plane disc wedge angles in the unloaded and loaded configurations were measured. Joint moments exerted by the axial compressive load were used to derive estimates of individual joint compliance. Findings The mean standing major Cobb angle for this patient series was 46°. Mean intra-observer measurement error for endplate inclination was 1.6°. Following loading, initially highly wedged discs demonstrated a smaller change in wedge angle, than less wedged discs for certain spinal levels (+ 2,+1,− 2 relative to the apex, (p < 0.05)). Highly wedged discs were observed near the apex of the curve, which corresponded to lower joint compliance in the apical region. Interpretation While individual patients exhibit substantial variability in disc wedge angles and joint compliance, overall there is a pattern of increased disc wedging near the curve apex, and reduced joint compliance in this region. Approaches such as this can provide valuable biomechanical data on in vivo spinal biomechanics of the scoliotic spine, for analysis of deformity progression and surgical planning.

J.W.Lindt’s Colonial man and Aborigine image from the GRAFTON ALBUM : “On chemistry and optics all does not depend, art must with these in triple union blend”

J.W.Lindt’s Colonial man and Aborigine image from the GRAFTON ALBUM: “On chemistry and optics all does not depend, art must with these in triple union blend” (text from J.W. Lindt’s photographic backing card) In this paper, I follow an argument that Lindt held a position in his particular colonial environment where he was simultaneously both an insider and an outsider and that such a position may be considered prerequisite in stimulating exchange. A study of the transition of J.W. Lindt in Grafton, N.S.W. in the 1860s from a traveller to a migrant and subsequently to a professional photographer, as well as Lindt’s photographic career, which evolved through strategic action and technical approaches to photography, bears witness to his cultural relativity. One untitled photograph from this period of work constructs a unique commentary of Australian colonial life that illustrates a non-hegemonic position, particularly as it was included in one of the first albums of photographs of Aborigines that Lindt gifted to an illustrious person (in this case the Mayor of Grafton). As in his other studio constructions, props and backdrops were arranged and sitters were positioned with care, but this photograph is the only one in the album that includes a non-Aborigine in a relationship to an Aborigine. An analysis of the props, technical details of the album and the image suggests a reconciliatory aspect that thwarts the predominant attitudes towards Aborigines in the area at that time.

A liquid biopsy for head and neck cancers

Head and neck cancer patients often present with advanced metastatic disease resulting in a poor 5-year survival. Therefore, there is a need for non-invasive diagnostic tools that could complement conventional imaging to inform clinicians of patient outcomes and treatment responses. A liquid biopsy addresses this unmet clinical need; a simple peripheral blood draw could provide information about the disseminated disease in terms of circulating tumor cells and circulating tumor DNA. Moreover, detectable tumor DNA in the saliva of head and neck cancer patients could signify the early signs of the disease and present an opportunity for clinical intervention. This review provides an overview of the current literature with regard to the feasibility of such a test in the head and neck cancer field and highlights the need for such a test.

The effect of habitat and environmental history on otolith chemistry of barramundi Lates calcarifer in estuarine populations of a regulated tropical river

We examine the microchemistry of otoliths of cohorts of a fished shed population of the large catadromous fish, barramundi Lates calcarifer from the estuary of a large tropical river. Barramundi from the estuary of the large, heavily regulated Fitzroy River, north eastern Australia were analysed by making transects of 87Sr/86Sr isotope and trace metal/Ca ratios from the core to the outer edge. Firstly, we examined the Sr/Ca, Ba/Ca, Mg/Ca and Mn/Ca and 87Sr/86Sr isotope ratios in otoliths of barramundi tagged in either freshwater or estuarine habitats that were caught by the commercial fishery in the estuary. We used 87Sr/86Sr isotope ratios to identify periods of freshwater residency and assess whether trace metal/Ca ratios varied between habitats. Only Sr/Ca consistently varied between known periods of estuarine or freshwater residency. The relationships between trace metal/Ca and river flow, salinity, temperature were examined in fish tagged and recaptured in the estuary. We found weak and inconsistent patterns in relationships between these variables in the majority of fish. These results suggest that both individual movement history within the estuary and the scale of environmental monitoring were reducing our ability to detect any patterns. Finally, we examined fish in the estuary from two dominant age cohorts (4 and 7 yr old) before and after a large flood in 2003 to ascertain if the flood had enabled fish from freshwater habitats to migrate to the estuary. There was no difference in the proportion of fish in the estuary that had accessed freshwater after the flood. Instead, we found that larger individuals with each age cohort were more likely to have spent a period in freshwater. This highlights the need to maintain freshwater flows in rivers. About half the fish examined had accessed freshwater habitats before capture. Of these, all had spent at least their first two months in marine salinity waters before entering freshwater and some did not enter freshwater until four years of age. This contrasts with the results of several previous studies in other parts of the range that found that access to freshwater swamps by larval barramundi was important for enhanced population productivity and recruitment.

Odour sampling 1: Physical chemistry considerations

The selection of an odour sampling device may influence the composition of the resulting odour sample. Limited comparison of emission rates derived from turbulent and essentially quiescent sampling devices confirms that the emission rates derived from these devices are quite different. There is therefore compelling evidence that current odour sampling practice should have greater regard for fundamental physical and chemical principles, the nature of the odour source and the conditions created by the sampling device. Such consideration may identify the most appropriate situations under which the use of these devices may or may not be correct.

Comparison of Culture and a Novel 5' Taq Nuclease Assay for Direct Detection of Campylobacter fetus subsp. venerealis in Clinical Specimens from Cattle

A Campylobacter fetus subsp. venerealis-specific 5' Taq nuclease PCR assay using a 3' minor groove binder-DNA probe (TaqMan MGB) was developed based on a subspecies-specific fragment of unknown identity (S. Hum, K. Quinn, J. Brunner, and S. L. On, Aust. Vet. J. 75:827-831, 1997). The assay specifically detected four C. fetus subsp. venerealis strains with no observed cross-reaction with C. fetus subsp. fetus-related Campylobacter species or other bovine venereal microflora. The 5' Taq nuclease assay detected approximately one single cell compared to 100 and 10 cells in the conventional PCR assay and 2,500 and 25,000 cells from selective culture from inoculated smegma and mucus, respectively. The respective detection limits following the enrichments from smegma and mucus were 5,000 and 50 cells/inoculum for the conventional PCR compared to 500 and 50 cells/inoculum for the 5' Taq nuclease assay. Field sampling confirmed the sensitivity and the specificity of the 5' Taq nuclease assay by detecting an additional 40 bulls that were not detected by culture. Urine-inoculated samples demonstrated comparable detection of C. fetus subsp. venerealis by both culture and the 5' Taq nuclease assay; however, urine was found to be less effective than smegma for bull sampling. Three infected bulls were tested repetitively to compare sampling tools, and the bull rasper proved to be the most suitable, as evidenced by the improved ease of specimen collection and the consistent detection of higher levels of C. fetus subsp. venerealis. The 5' Taq nuclease assay demonstrates a statistically significant association with culture (2 = 29.8; P < 0.001) and significant improvements for the detection of C. fetus subsp. venerealis-infected animals from crude clinical extracts following prolonged transport.

Site-Specific Functionalization of Hyperbranched Polymers Using ``Click'' Chemistry

Different strategies for functionalization of the core region and periphery of core-shell type hyperbranched polymers (HBP) using the ``click'' reaction have been explored. For achieving periphera functionalization, an AB(2) + A-R-1 + A-R-2 type copolymerization approach was used, where A-R-1 is heptaethylene glycol monomethyl ether (HPEG-M) and A-R-2 is tetraethylene glycol monopropargyl ether (TEG-P). A very small mole fraction of the propargyl containing monomer, TEG-P, was used to ensure that the water-solubility of the hyperbranched polymer is minimally affected. Similarly, to incorporate propargyl groups in the core region, a new propargyl group bearing B-2-typ monomer was designed and utilized in an AB(2) + A(2) + B-2 + A-R-1 type copolymerization, such that the total mole fraction of B-2 + A(2) is small and their mole-ratio is 1: 1. Further, using a combination of both the above approaches, namely AB(2) + A(2) + B-2 + A-R-1 + A-R-2, hyperbranched structures that incorporate propargyl groups both at theperiphery and within the core were synthesized. Since the AB(2) monomer carries a hexamethylene spacer (C-6) and the periphery is PEGylated all the derivatized polymers form core-shell type structures in aqueous solutions. Attempts were made to ascertain and probe the location of the propargyl groups in these HBP's, by ``clicking'' azidomethylpyrene, onto them. However, the fluorescence spectra of aqueous solutions of the pyrene derivatized polymers were unable to discriminate between the various locations, possibly because the relatively hydrophobic pyrene units insert themselves into the core region to minimize exposure to water.

Packed bed bioreactor for the isolation and expansion of placental-derived Mesenchymal Stromal Cells

Large numbers of Mesenchymal stem/stromal cells (MSCs) are required for clinical relevant doses to treat a number of diseases. To economically manufacture these MSCs, an automated bioreactor system will be required. Herein we describe the development of a scalable closed-system, packed bed bioreactor suitable for large-scale MSCs expansion. The packed bed was formed from fused polystyrene pellets that were air plasma treated to endow them with a surface chemistry similar to traditional tissue culture plastic. The packed bed was encased within a gas permeable shell to decouple the medium nutrient supply and gas exchange. This enabled a significant reduction in medium flow rates, thus reducing shear and even facilitating single pass medium exchange. The system was optimised in a small-scale bioreactor format (160 cm2) with murine-derived green fluorescent protein-expressing MSCs, and then scaled-up to a 2800 cm2 format. We demonstrated that placental derived MSCs could be isolated directly within the bioreactor and subsequently expanded. Our results demonstrate that the closed system large-scale packed bed bioreactor is an effective and scalable tool for large-scale isolation and expansion of MSCs.

An imagery-based road map to tackle maladaptive motivation in clinical disorders

There is now a widespread recognition of the importance of mental imagery in a range of clinical disorders (1). This provides the potential for a transdiagnostic route to integrate some aspects of these disorders and their treatment within a common framework. This opinion piece argues that we need to understand why imagery is such a central and recurring feature, if we are to progress theories of the origin and maintenance of disorders. This will aid us in identifying therapeutic techniques that are not simply targeting imagery as a symptom, but as a manifestation of an underlying problem. As papers in this issue highlight, imagery is a central feature across many clinical disorders, but has been ascribed varying roles. For example, the involuntary occurrence of traumatic memories is a diagnostic criterion for PTSD (2), and it has been suggested that multisensory imagery of traumatic events normally serves a functional role in allowing the individual to reappraise the situation (3), but that this re-appraisal is disabled by extreme affective responses. In contrast to the disabling flashbacks associated with PTSD, depressed adults who experience suicidal ideation often report “flash forward” imagery related to suicidal acts (4), motivating them to self-harm. Socially anxious individuals who engage in visual imagery about giving a talk in public become more anxious and make more negative predictions about future performance than others who engage in more abstract, semantic processing of the past event (5). People with Obsessive Compulsive Disorder (OCD) frequently report imagery of past adverse events, and imagery seems to be associated with severity (6). The content of intrusive imagery has been related to psychotic symptoms (7), including visual images of the catastrophic fears associated with paranoia and persecution. Imagery has been argued (8) to play a role in the maintenance of psychosis through negative appraisals of imagined voices, misattribution of sensations to external sources, by the induction of negative mood states that trigger voices, and through maintenance of negative schemas. In addiction and substance dependence, Elaborated Intrusion (EI) Theory (9, 10) emphasizes the causal role that imagery plays in substance use, through its role in motivating an individual to pursue goals directed toward achieving the pleasurable outcomes associated with substance use...