Hydrothermal synthesis of V0.13Mo0.87O2.935 nanowires with strong blue photoluminescence

Hexagonal V0.13Mo0.87O2.935 nanowires were hydrothermally synthesized at 220 °C for the first time. X-ray diffraction and field-emission scanning electron microscopy were utilized to characterize the phase and morphology of the nanowires, respectively. Transmission electron microscopy and selected area electron diffraction indicate that the nanowires are single crystalline, growing along the [001] direction. Interestingly, the nanowires easily become amorphous under the electron irradiation. The comparative hydrothermal experiments show that the molar ratio between the starting reagents of Mo and NH4VO3 plays a vital role in the anisotropic growth of nanowires. The photoluminescence measurement demonstrates that these nanowires exhibit two strong emission peaks at 420 and 438 nm, which are probably related to the intrinsic oxygen vacancies.

Profiling of secondary metabolites in blue lupin inoculated with Phytophthora cinnamomi following phosphite treatment

In order to discover phytochemicals that are potentially bioactive against Phytophthora cinnamomi, (a soil-borne plant pathogen) a metabolite profiling protocol for investigation of metabolic changes in Lupinus angustifolius L. plant roots in response to pathogen challenge has been established. Analysis of the metabolic profiles from healthy and P. cinnamomi-inoculated root tissue with high resolution mass spectrometry and nuclear magnetic resonance spectroscopy confirmed that although susceptible, L. angustifolius upregulated a defence associated genistein and 2′-hydroxygenistein-based isoflavonoid and a soyasapogenol saponin at 12h post inoculation which increased in concentration at 72h post inoculation. In contrast to the typical susceptible interaction, the application of a phosphorous-based treatment to L. angustifolius foliage 48h before P. cinnamomi challenge negated the ability of the pathogen to colonise the root tissue and cause disease. Importantly, although the root profiles of water-treated and phosphite-treated plants post pathogen inoculation contained the same secondary metabolites, concentration variations were observed. Accumulation of secondary metabolites within the P. cinnamomi-inoculated plants confirms that pathogen ingress of the root interstitially occurs in phosphite-treated plants, confirming a direct mode of action against the pathogen upon breaching the root cells.

Fine-scale foraging habitat and behavioural responses of pygmy blue whales

This study characterised, for the first time, periodically abundant and variable pygmy blue whale prey across the southern Australian shelf. Prey was closely tied to weather and ocean features. Foraging habitat and whale interactions described here will aid rapid assessments of profitable whale areas and forecasting effects of ongoing habitat change.

Red-green-blue electrogenerated chemiluminescence utilizing a digital camera as detector

Exploiting the distinct excitation and emission properties of concomitant electrochemiluminophores in conjunction with the inherent color selectivity of a conventional digital camera, we create a new strategy for multiplexed electrogenerated chemiluminescence detection, suitable for the development of low-cost, portable clinical diagnostic devices. Red, green and blue emitters can be efficiently resolved over the three-dimensional space of ECL intensity versus applied potential and emission wavelength. As the relative contribution ratio of each emitter to the photographic RGB channels is constant, the RGB ECL intensity versus applied-potential curves could be effectively isolated to a single emitter at each potential.

No detectable impact of small-scale disturbances on ‘blue carbon’ within seagrass beds

Seagrass meadows are among the most efficient and long-term carbon sinks on earth, but disturbances could threaten this capacity, so understanding the impacts of disturbance on carbon stored within seagrass meadows—‘blue carbon’—is of prime importance. To date, there have been no published studies on the impacts of seagrass loss on ‘blue carbon’ stocks. We experimentally created several kinds of small-scale disturbances, representative of common grazer and boating impacts, within seagrass (Zostera nigracaulis) meadows in Port Phillip Bay (Australia) and measured the impacts on sediment organic carbon stocks (‘Corg’, and other geochemical variables—%N, δ13C, δ15N). Disturbance had no detectable effect on Corg levels within seagrass sediments, even for high-intensity disturbance treatments, which remained bare (i.e. no seagrass recovery) for 2 years after the disturbance. These findings challenge the widely held assumption that disturbance and concomitant loss of seagrass habitat cause release of carbon, at least for small-scale disturbances. We suggest that larger (e.g. meadow scale) disturbances may be required to trigger losses of ‘blue carbon’ from seagrass meadows.

An improved TIGER2 implementation for NAMD suitable for the Blue Gene architecture

Here we present an improved implementation of the TIGER2 Replica Exchange Molecular Dynamics (REMD) method, using the replica exchange Application Programming Interface (API) found in contemporary versions of the NAMD Molecular Dynamics Package. The implementation takes the form of a TCL script which is used in conjunction with the standard configuration file. This implementation is validated against a previous TIGER2 implementation, as well as data reported for the original TIGER2 simulations. Our implementation is compatible with a range of architectures; crucially it enables the use of this wrapper with the BlueGene/Q architecture, in addition to the x86 architecture. Program summary: Program title: TIGER2-NAMD. Catalogue identifier: AEWC_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEWC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland. Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 34151. No. of bytes in distributed program, including test data, etc.: 424217. Distribution format: tar.gz. Programming language: Tcl 8.5. Computer: x86 Clusters, BlueGene/Q, Workstations. Operating system: Linux, IBM Compute Node Kernel. Has the code been vectorised or parallelised?: Yes. MPI Parallelism. Classification: 3. External routines: NAMD 2.9 (http://www.ks.uiuc.edu/Research/namd/). Nature of problem: Replica Exchange Molecular Dynamics. Solution method: Each replica runs through multiple cycles of heating and cooling with exchanges between them being attempted. Running time: Typically 30 mins, up to an hour.

Loss of 'blue carbon' from coastal salt marshes following habitat disturbance

Increased recognition of the global importance of salt marshes as 'blue carbon' (C) sinks has led to concern that salt marshes could release large amounts of stored C into the atmosphere (as CO2) if they continue undergoing disturbance, thereby accelerating climate change. Empirical evidence of C release following salt marsh habitat loss due to disturbance is rare, yet such information is essential for inclusion of salt marshes in greenhouse gas emission reduction and offset schemes. Here we investigated the stability of salt marsh (Spartinaalterniflora) sediment C levels following seagrass (Thallasiatestudinum) wrack accumulation; a form of disturbance common throughout the world that removes large areas of plant biomass in salt marshes. At our study site (St Joseph Bay, Florida, USA), we recorded 296 patches (7.5 ± 2.3 m(2) mean area ± SE) of vegetation loss (aged 3-12 months) in a salt marsh meadow the size of a soccer field (7 275 m(2)). Within these disturbed patches, levels of organic C in the subsurface zone (1-5 cm depth) were ~30% lower than the surrounding undisturbed meadow. Subsequent analyses showed that the decline in subsurface C levels in disturbed patches was due to loss of below-ground plant (salt marsh) biomass, which otherwise forms the main component of the long-term 'refractory' C stock. We conclude that disturbance to salt marsh habitat due to wrack accumulation can cause significant release of below-ground C; which could shift salt marshes from C sinks to C sources, depending on the intensity and scale of disturbance. This mechanism of C release is likely to increase in the future due to sea level rise; which could increase wrack production due to increasing storminess, and will facilitate delivery of wrack into salt marsh zones due to higher and more frequent inundation.