Use of PAM in Australian irrigated agriculture

In many countries using polyacrylamides PAM as a soil conditioner has increased in recent years, particularly since the introduction of new generation, more cost effective products. Using these products on-farm has become more economically feasible because of their low application rates. They also have important environment, soil conservation and irrigation efficiency benefits. This article summarises the important findings from a series of experiments conducted over a five year period

Investigation of dominant hydrological processes in a tropical catchment in a monsoonal climate via the downward approach

This study explores the dominant processes that may be responsible for the observed streamflow response in Seventeen Mile Creek, a tropical catchment located in a monsoonal climate in Northern Territory, Australia. The hydrology of this vast region of Australia is poorly understood due to the low level of information and gauging that are available. Any insights that can be gained from the few well gauged catchments that do exist can be valuable for predictions and water resource assessments in other poorly gauged or ungauged catchments in the region. To this end, the available rainfall and runoff data from Seventeen Mile Creek catchment are analyzed through the systematic and progressive development and testing of rainfall-runoff models of increasing complexity, by following the "downward" or "top-down" approach. This procedure resulted in a multiple bucket model (4 buckets in parallel). Modelling results suggest that the catchment's soils and the landscape in general have a high storage capacity, generating a significant fraction of delayed runoff, whereas saturation excess overland flow occurs only after heavy rainfall events. The sensitivity analyses carried out with the model with regard to soil depth and temporal rainfall variability revealed that total runoff from the catchment is more sensitive to rainfall variations than to soil depth variations, whereas the partitioning into individual components of runoff appears to be more influenced by soil depth variations. The catchment exhibits considerable inter-annual variability in runoff volumes and the greatest determinant of this variability turns out to be the seasonality of the climate, the timing of the wet season, and temporal patterns of the rainfall. The water balance is also affected by the underlying geology, nature of the soils and the landforms, and the type, density and dynamics of vegetation, although information pertaining to these is lacking

Water Balance of Flooded Rice in the Tropics

Department of Agriculture and Food, WA staff member authored Water Balance of Flooded Rice in the Tropics in the publication Irrigation and Drainage - Sustainable Strategies and Systems’, edited by Muhammad Salik Javaid, published by INTECH, May 2015 Chapter Summary: Excess groundwater recharge rates under irrigated agriculture may lead to problems such as rising watertable, waterlogging and salinity. In irrigated areas, growers may need to manage this water and hence, understanding what leakage is attributed to what crops will become more important. In this study, evaporation, transpiration, and deep percolation losses were estimated for ponded rice culture, using a set of three lysimeters and lockup bay tests. The average deep percolation losses were estimated to be less than 0.97 mm/day or approximately 1 ML/ha for the crop cycle. At this rate, deep percolation under ponded rice culture in Cununurra clay soils is within accepted leakage rates and the rates should not unduly affect growers or environmental managers in terms of rising groundwater levels, waterlogging and salinity.https://researchlibrary.agric.wa.gov.au/books/1000/thumbnail.jp

Exploring the factors that determine the success of global venture capital investing in the emerging markets of South East Asia using a grounded theory and case studies approach

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Agronomic Options for Profitable Rice-based Farming System in Northern Australia

Minimum air temperatures less than 15°C had biggest impact on varietal performance. Cold damage during the months of June and July warrants selection of varieties with cold tolerance for this environment, especially for the aerobic rice system. Ponded water has 4-8°C advantage over the air temperature, thus providing some protection against such cold damage. This has resulted in higher yields under flooded system. Planting dates, varying from late-February to late-May, were found to play a crucial role for plants to escape the low temperature damage at critical growth stages. Among the varieties tested, selected tropical varieties yielded higher than the temperate varieties. Yunlu 29 has been identified as the best variety adapted for aerobic rice system in the Ord. NTR 426 was found to outperform all other tested varieties under the flooded system in this environment. Greater focus must be paid on quality of harvested grain. A complete analysis of data generated in trials conducted from 2009 to 2015 at all sites in WA and NT could help to identify environmental differences between sites and therefore target specific/broad adaptation of varieties with good yield stability. Future work in northern Australia should consider screening a greater range of fragrant and aromatic rice. Traditionally, fragrant rice varieties attain greater levels of aromatic components in tropical regions. These are high value varieties and represent opportunities for import substitution in Australian markets. There is an opportunity for Australia to tap further into the international rice market by producing these speciality rices in the tropical environments of northern Australia. These are some of the factors that need to be considered to establish a viable rice industry in the ORIA and NT regions. Rice crop modelling could add significant value and extend the experimental work and field trials, particularly in helping to quantify long-term risks in rice production due to low/high temperatures, climate change, and so on. Once they have been tested and validated, cropping systems models (for example, Agricultural Production Systems Simulator [APSIM]) can give valuable insights into climatic risks over a much longer period (50-100 years) than experiments/field-trials.https://researchlibrary.agric.wa.gov.au/books/1011/thumbnail.jp

PHYSICO-CHEMICAL AND PHYTO-CHEMICAL STUDY OF RHIZOME of Cyperus rotundus LINN

Cyperus rotundus L., (Family Cyperaceae), also known as purple nutsedge or nutgrass, is a common perennial plant. This is a multipurpose plant, widely used in traditional medicine around the world to treat various diseases such as indigestion, constipation, dysentery, abdominal distention, neurogenic gastralgia, chest pains, irregular menstruation, painful menstruation, skin diseases, furuncle infections, leprosy, sprains and bruises, and fever. It has the property of therapeutic actions such as analgesic, alternative, astringent, antispasmodic, antibacterial, carminative, contraceptive, demulcent, emmenagogue, emollient, febrifuge, immunostimulant, laxative, tonic, vermifuge. Pharmacognostical investigations are the first and foremost step to determine the identity and to assess the quality of plant species. The aim of the study was to evaluate the parameter to determine the quality of the rhizome of Cyperus rotundus L. These studies comprise to investigate macroscopy, microscopy, physicochemical parameters, preliminary phytochemical screening and fluorescence characteristics. The findings may provide useful information with regard to its identification and standardization in future

Investigating the regulation of DNA non-homologous end-joining through Ku70/80 interacting factors

DNA double-strand breaks are the most deleterious type of DNA damage that cells experience, which makes the study of double-strand break repair extremely important. Unrepaired or aberrantly repaired DNA can result in changes to core genes with critical function and thus lead to multiple diseases. Two main repair pathways for double-strand breaks exist: homologous recombination (HR) and non-homologous end-joining (NHEJ). Whilst the regulation of HR has been heavily investigated, the regulation of NHEJ remains to be fully explored. The aim of this thesis is to investigate the regulation of DNA NHEJ through interacting factors of the core NHEJ protein heterodimer, Ku70/80 (Ku). This thesis consists of three main research projects. The first, explores the potential role of the CUL4 substrate adaptor, WDR76, in the removal of Ku from sites of DNA damage. Data presented here highlight a role of WDR76 in the DNA damage response (DDR), and through effects on Ku removal kinetics, suggest a role for WDR76 in the regulating NHEJ. The second research project investigates a potential cyclin-dependent kinase phosphorylation site on the protein paralog of XRCC4 and XLF (PAXX). As PAXX is a Ku interactor with a role in NHEJ, the effect of PAXX phosphorylation is investigated as a potential NHEJ regulatory system. Lastly, I investigate the role of the RecQ helicase WRN, whose precise roles in the DDR are unclear. As an interactor of both HR and NHEJ proteins, WRN may affect the regulation of both pathways. WRN knockout cells were generated and a CRISPR-Cas9 screen performed to identify suppressors of WRN sensitivity to DNA damage. The targets identified offer insights into WRN function.BBSRC Horizon Discovery Steve Jackson Laborator

Theoretical investigation of process controls upon flood frequency: role of thresholds

International audienceTraditional statistical approaches to flood frequency inherently assume homogeneity and stationarity in the flood generation process. This study illustrates the impact of heterogeneity associated with threshold non-linearities in the storage-discharge relationship associated with the rainfall-runoff process upon flood frequency behaviour. For a simplified, non-threshold (i.e. homogeneous) scenario, flood frequency can be characterised in terms of rainfall frequency, the characteristic response time of the catchment, and storm intermittency, modified by the relative strength of evaporation. The flood frequency curve is then a consistent transformation of the rainfall frequency curve, and could be readily described by traditional statistical methods. The introduction of storage thresholds, namely a field capacity storage and a catchment storage capacity, however, results in different flood frequency "regions" associated with distinctly different rainfall-runoff response behaviour and different process controls. The return period associated with the transition between these regions is directly related to the frequency of threshold exceedence. Where threshold exceedence is relatively rare, statistical extrapolation of flood frequency on the basis of short historical flood records risks ignoring this heterogeneity, and therefore significantly underestimating the magnitude of extreme flood peaks

Antibacterial properties of some marine algae of Sri Lanka

The authors report on the antibacterial activity of 11 algae, green, brown and red. Prepared extracts were tested, and varying degrees of activity were exhibited. Most activity was shown by Ulva fasciata, Sargassum cervicone and Halimeda macroloba

Component-based Attention for Large-scale Trademark Retrieval

The demand for large-scale trademark retrieval (TR) systems has significantly increased to combat the rise in international trademark infringement. Unfortunately, the ranking accuracy of current approaches using either hand-crafted or pre-trained deep convolution neural network (DCNN) features is inadequate for large-scale deployments. We show in this paper that the ranking accuracy of TR systems can be significantly improved by incorporating hard and soft attention mechanisms, which direct attention to critical information such as figurative elements and reduce attention given to distracting and uninformative elements such as text and background. Our proposed approach achieves state-of-the-art results on a challenging large-scale trademark dataset.Comment: Fix typos related to authors' informatio