Modelling the potential of integrated vegetation bands (IVB) to retain stormwater runoff on steep hillslopes of Southeast Queensland, Australia

Rainfall intensity is predicted to increase under a changing climate, leading to increased risks of hillslope erosion, downstream sedimentation and flooding. For many catchments used for grazing and agricultural land uses, it will become increasingly important to maintain ecohydrological functioning despite climatic extremes. One means to achieve this is through strategic reforestation using locally endemic species, in spatial configurations that effectively intercept, retain or and redistribute overland flows. This paper adopts a modelling approach for investigating the potential of one such design termed “integrated vegetation bands” (IVB), to increase the retention of runoff across steep hillslopes, particularly in the sub-tropics where rainstorms are becoming increasingly intense. A spatially distributed simulation model (MIKE-SHE) was applied to a steep, grazed catchment (Maronghi Creek catchment, Southeast Queensland, Australia) to compare stormwater runoff characteristics between: (1) the existing pasture land cover; and (2) a series of hypothetical IVB added across this pasture land. The IVB were approximately 20 m wide, and configured at 5% gradient towards ridgelines. Results for estimates of overland flow depth and infiltration (spatial), and accumulative water balance (temporal), confirm that the area of hillslope retaining > 10 mm/day more runoff increased by 22% under IVB compared to the pasture land use. Excluding the IVB themselves, the area of hillslope where runoff retention increased was 11%. During the most intense rainfall, IVB held up to 25% greater water depth and had 10% greater infiltration at the hillslope scale. At the sub-catchment scale, discharge decreased by 7% and infiltration increased by 23%. The findings for sub-tropical landscapes presented here are consistent with studies conducted in temperate regions. Based on the results of this preliminary modelling work, the IVB concept has been established as a paired-catchment field trial in a high rainfall catchment in Southeast Queensland, Australia

Blending Landsat and MODIS Data to Generate Multispectral Indices: A Comparison of “Index-then-Blend” and “Blend-then-Index” Approaches

The objective of this paper was to evaluate the accuracy of two advanced blending algorithms, Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) and Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) to downscale Moderate Resolution Imaging Spectroradiometer (MODIS) indices to the spatial resolution of Landsat. We tested two approaches: (i) "Index-then-Blend" (IB); and (ii) "Blend-then-Index" (BI) when simulating nine indices, which are widely used for vegetation studies, environmental moisture assessment and standing water identification. Landsat-like indices, generated using both IB and BI, were simulated on 45 dates in total from three sites. The outputs were then compared with indices calculated from observed Landsat data and pixel-to-pixel accuracy of each simulation was assessed by calculating the: (i) bias; (ii) R; and (iii) Root Mean Square Deviation (RMSD). The IB approach produced higher accuracies than the BI approach for both blending algorithms for all nine indices at all three sites. We also found that the relative performance of the STARFM and ESTARFM algorithms depended on the spatial and temporal variances of the Landsat-MODIS input indices. Our study suggests that the IB approach should be implemented for blending of environmental indices, as it was: (i) less computationally expensive due to blending single indices rather than multiple bands; (ii) more accurate due to less error propagation; and (iii) less sensitive to the choice of algorithm

Nano-scale superhydrophobicity: suppression of protein adsorption and promotion of flow-induced detachment

Wall adsorption is a common problem in microfluidic devices, particularly when proteins are used. Here we show how superhydrophobic surfaces can be used to reduce protein adsorption and to promote desorption. Hydrophobic surfaces, both smooth and having high surface roughness of varying length scales (to generate superhydrophobicity), were incubated in protein solution. The samples were then exposed to flow shear in a device designed to simulate a microfluidic environment. Results show that a similar amount of protein adsorbed onto smooth and nanometer-scale rough surfaces, although a greater amount was found to adsorb onto superhydrophobic surfaces with micrometer scale roughness. Exposure to flow shear removed a considerably larger proportion of adsorbed protein from the superhydrophobic surfaces than from the smooth ones, with almost all of the protein being removed from some nanoscale surfaces. This type of surface may therefore be useful in environments, such as microfluidics, where protein sticking is a problem and fluid flow is present. Possible mechanisms that explain the behaviour are discussed, including decreased contact between protein and surface and greater shear stress due to interfacial slip between the superhydrophobic surface and the liquid

A human coronavirus responsible for the common cold massively kills dendritic cells but not monocytes

Copyright @ 2012, American Society for Microbiology.Human coronaviruses are associated with upper respiratory tract infections that occasionally spread to the lungs and other organs. Although airway epithelial cells represent an important target for infection, the respiratory epithelium is also composed of an elaborate network of dendritic cells (DCs) that are essential sentinels of the immune system, sensing pathogens and presenting foreign antigens to T lymphocytes. In this report, we show that in vitro infection by human coronavirus 229E (HCoV-229E) induces massive cytopathic effects in DCs, including the formation of large syncytia and cell death within only few hours. In contrast, monocytes are much more resistant to infection and cytopathic effects despite similar expression levels of CD13, the membrane receptor for HCoV-229E. While the differentiation of monocytes into DCs in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 requires 5 days, only 24 h are sufficient for these cytokines to sensitize monocytes to cell death and cytopathic effects when infected by HCoV-229E. Cell death induced by HCoV-229E is independent of TRAIL, FasL, tumor necrosis factor alpha, and caspase activity, indicating that viral replication is directly responsible for the observed cytopathic effects. The consequence of DC death at the early stage of HCoV-229E infection may have an impact on the early control of viral dissemination and on the establishment of long-lasting immune memory, since people can be reinfected multiple times by HCoV-229E

Grower case study on economics of an improved farming system

There has been a lot of research done by the Sugar Yield Decline Joint Venture providing insights and recommendations on how to improve the farming system to combat yield decline in cane fields. This paper explores a cane farming family's experience with implementing practices advocated by the YDJV and describes the changes they have made to their farming system. This description includes the specific practices that they were using before implementing the recommendations, the changes they have made, and the economic, environmental and social impacts that these have had on their business. The new farming system includes controlled traffic, reduced tillage, peanut rotation, flood irrigation from new on-farm storage, with GPS technology linked to land levelling, planting, harvesting and fertiliser application. One significant finding was the changed farming system showed a return on investment on the old farming system of minus 10.8% improving to plus 5.9% for the new system. Cane gross margin per hectare on the old system was ñ$148 versus$1157 on the new system. The Loeskow family cannot stress enough the need to continually investigate improved farming practices and invest in new technology and equipment. A preparedness to continually change has been the key to the Loeskow family success

Nanostructure of cellulose microfibrils in spruce wood

The structure of cellulose microfibrils in wood is not known in detail, despite the abundance of cellulose in woody biomass and its importance for biology, energy, and engineering. The structure of the microfibrils of spruce wood cellulose was investigated using a range of spectroscopic methods coupled to small-angle neutron and wide-angle X-ray scattering. The scattering data were consistent with 24-chain microfibrils and favored a “rectangular” model with both hydrophobic and hydrophilic surfaces exposed. Disorder in chain packing and hydrogen bonding was shown to increase outwards from the microfibril center. The extent of disorder blurred the distinction between the I alpha and I beta allomorphs. Chains at the surface were distinct in conformation, with high levels of conformational disorder at C-6, less intramolecular hydrogen bonding and more outward-directed hydrogen bonding. Axial disorder could be explained in terms of twisting of the microfibrils, with implications for their biosynthesis

Balancing Water Use Efficiency and Milk Production in the Sub-Tropics

Queensland dairy farmers have had to confront in the last 5 years deregulation of the milk pricing system, resulting in a 25% reduction in farm gate price for milk in the year 2000, and drought. Many storage dams are significantly below capacity and regulatory authorities have imposed restrictions on irrigation water allocations. Major changes in farm business strategies were needed to overcome the shortfall in milk income. Production systems had to change to deliver more milk more efficiently and become more profitable. A farmlet study was developed in the sub-tropical dairy region of Queensland to evaluate 5 very different farm systems identified by a group of experts as capable of tripling production whilst achieving a 10% return on assets and 600,000 L/labour unit. This paper compares the water use efficiencies and milk production of these systems

Evaluation of the water use efficiency of dairy production using crops and pastures

This study evaluated the water use efficiency (WUE) of milk and forage production from a range of temperate and tropical forages on 5 dairy farmlets and a small field plot study located at Mutdapilly Research Station in south east Queensland. The feedbase had a greater affect on the WUE of milk production than the volume of irrigation and rainfall received. For instance, the high irrigation, high quality temperate pasture based (M4) farmlet received an additional 36% volume of water when compared to the crop based feedlot (M5) farmlet, though milk production from forage was 30% less. This difference in efficiency occurred in part from the superior WUE of the irrigated maize (Zea mays) summer crop with 3.4 t DM/ML and lucerne (Medicago sativa) winter crop with 2 t DM/ML, and the increased efficiency of herbage utilisation from the conservation of crops compared with grazing of pastures. The raingrown (M1) farmlet’s WUE of milk production was relatively high, however forage production was limited and consequently milk yield was comparatively low. The range in herbage WUE associated with forage species was consistent between the farmlet and small plot studies. Farmers are challenged with striking a balance between selecting forage types that optimise WUE and those that increase diet quality

Establishment Techniques to Increase the Production of Italian Ryegrass (\u3cem\u3eLolium multiflorum\u3c/em\u3e) Over-Sown into an Irrigated Kikuyu (\u3cem\u3ePennisetum clandestinum\u3c/em\u3e) Pasture

Irrigated mixed pastures of kikuyu (Pennisetum clandestinum) over-sown with Italian ryegrass (Lolium multiflorum) in the cool-season (May-October) can produce large amounts of biomass in a sub-tropical environment (Botha et al. 2008). However, appropriate pasture management practices are required to suppress the aggressive growth of kikuyu prior to autumn, in order to facilitate establishment of ryegrass seedlings. The present study evaluated ryegrass establishment techniques on the dry matter (DM) production, botanical composition and forage quality of a mixed sward containing kikuyu