355 research outputs found

    An economic model for evaluating strategies on the south coast of W.A. which reduce wind erosion : documentation

    Get PDF
    The sandplain region on the south coast has predominately sandy soils which are subject to erosive winds when ground cover is likely to be scarce. This can often result in production losses of crop and pasture. There is concern that wind erosion will lead to the depletion of the soil resource in the long term. The model is multi-period linear programming with a planning horizon of 10 years. Effects of wind erosion on production can be imposed on the model for the first five years after the erosion event

    The effect on farm profit of conserving stubble to prevent wind erosion

    Get PDF
    Over-grazing of stubbles is a major cause of winf erosion on WesternAustralian farms. Stubble contributes to the \u27roughness\u27 of the paddock; as the roughness is reduced, the risk of winf erosion is increased. The risk of lupinosis in sheep has previously reduced the likelihood of lupin stubble being over grazed, but the development of Gungurru, a phomopsis-resistent variety of lupin, has increased the potential for over-grazing and hence the probability of wind erosion. This article describes the economic benefit (or cost) of conserving stubble at the conservation standards

    Derivation of supply curves for catchment water effluents meeting specific salinity concentration targets in 2050: linking farm and catchment level models or “Footprints on future salt / water planes”

    Get PDF
    The salt burden in a stream reflects the blend of salty and fresh flows from different soil areas in its catchment. Depending not only on long-run rainfall, water yields from a soil are also determined by land cover: lowest if the area is forested and greatest if cleared. Water yields under agro-forestry, lucerne pasture, perennial grass pasture, and annual pasture or cropping options span the range of water yields between the extremes of forested and cleared lands. This study explores quantitative approaches for connecting the hydrologic and economic consequences of farm-level decisions on land cover (productive land uses) to the costs of attaining different catchment level targets of water volumes and salt reaching downstream users; environmental, agricultural, domestic, commercial and industrial. This connection is critical for the resolution of the externality dilemma of meeting downstream demands for water volume and quality. New technology, new products and new markets will expand options for salinity abatement measures in the dryland farming areas of watershed catchments. The development of appropriate policy solutions to address demands for water volumes and quality depends on the possibility of inducing targeted land use change in those catchments or parts of catchments where decreased saline flows or increased fresh water flows can return the best value for money. This study provides such a link.salinity, targets, opportunity cost, concentration, dilution, effluent, externality, supply, demand, policy, water quality, new technology, new markets, Resource /Energy Economics and Policy,

    The Structural Determinants of Insulin-Like Peptide 3 Activity

    Get PDF
    Insulin-like peptide 3 (INSL3) is a hormone and/or paracrine factor which is a member of the relaxin peptide family. It has key roles as a fertility regulator in both males and females. The receptor for INSL3 is the leucine rich repeat (LRR) containing G-protein coupled receptor 8 (LGR8) which is now known as relaxin family peptide receptor 2 (RXFP2). Receptor activation by INSL3 involves binding to the LRRs in the large ectodomain of RXFP2 by residues within the B-chain of INSL3 as well as an interaction with the transmembrane exoloops of the receptor. Although the binding to the LRRs is well characterized the features of the peptide and receptor involved in the exoloop interaction are currently unknown. This study was designed to determine the key INSL3 determinants for RXFP2 activation. A chimeric peptide approach was first utilized to demonstrate that the A-chain is critical for receptor activation. Replacement of the INSL3 A-chain with that from the related peptides INSL5 and INSL6 resulted in complete loss of activity despite only minor changes in binding affinity. Subsequent replacement of specific A-chain residues with those from the INSL5 peptide highlighted that the N-terminus of the A-chain of INSL3 is critical for its activity. Remarkably, replacement of the entire N-terminus with four or five alanine residues resulted in peptides with near native activity suggesting that specific residues are not necessary for activity. Additionally removal of two amino acids at the C-terminus of the A-chain and mutation of Lys-8 in the B-chain also resulted in minor decreases in peptide activity. Therefore we have demonstrated that the activity of the INSL3 peptide is driven predominantly by residues 5–9 in the A-chain, with minor additional contributions from the two C-terminal A-chain residues and Lys-8 in the B-chain. Using this new knowledge, we were able to produce a truncated INSL3 peptide structure which retained native activity, despite having 14 fewer residues than the parent peptide

    An assessment of the efficacy of deep drains constructed in the wheatbelt of Western Australia Part 1 A discussion on drainage implmentation in the wheatbelt : a case study review, summary, conclusions and recommendations

    Get PDF
    Australia has undertaken a strategic review of current and historical deep drainage projects. A \u27rapid appraisal\u27 methodology was utilised, based principally on existing hydrological investigations and interpretation and anecdotal evidence provided by landholders to clarify the role of drainage in managing water in dry land rural landscapes. The objectives of this discussion paper are to: 1. Review the current status of groundwater drainage practice 2. Provide an assessment of deep drains in the landscape and 3. Propose recommendations on the development of drainage policy to enable the application of best management practice in groundwater drainage.https://researchlibrary.agric.wa.gov.au/bulletins/1012/thumbnail.jp

    Moyamoya Disease in Pregnancy: Management after Intracranial Bypass Grafting

    Get PDF
    Moyamoya disease (MD) is a chronic, progressive cerebrovascular disease distinguished by bilateral stenosis or occlusion of the arteries around the circle of Willis with resulting prominent arterial collateral circulation. We describe a pregnant woman in whom this diagnosis was confirmed by cerebral angiogram and treated with bilateral superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting prior to conception. The patient was managed with strict blood pressure monitoring and low-dose aspirin antepartum, intrapartum, and postpartum. The patient presented in spontaneous labor at term and underwent a spontaneous vaginal delivery without complications

    A functional link between bone morphogenetic proteins and insulin-like peptide 3 signaling in modulating ovarian androgen production

    Get PDF
    Bone morphogenetic proteins (BMP) are firmly implicated as intra-ovarian regulators of follicle development and steroidogenesis. Here we report a microarray analysis showing that treatment of cultured bovine theca cells (TC) with BMP6 significantly (>2-fold; P<0.01) up- or down-regulated expression of 445 genes. Insulin-like peptide 3 (INSL3) was the most heavily down-regulated gene (-43-fold) with CYP17A1 and other key transcripts involved in TC steroidogenesis including LHCGR, INHA, STAR, CYP11A1 and HSD3B1 also down-regulated. BMP6 also reduced expression of NR5A1 encoding steroidogenic factor-1 known to target the promoter regions of the aforementioned genes. Real-time PCR confirmed these findings and also revealed a marked reduction in expression of INSL3 receptor (RXFP2). Secretion of INSL3 protein and androstenedione were also suppressed suggesting a functional link between BMP and INSL3 pathways in controlling androgen synthesis. RNAi-mediated knockdown of INSL3 reduced INSL3 mRNA and secreted protein level (75 and 94%, respectively) and elicited a 77% reduction in CYP17A1 mRNA level and 83% reduction in androstenedione secretion. Knockdown of RXFP2 also reduced CYP17A1 mRNA level (81%) and androstenedione secretion (88%). Conversely, treatment with exogenous (human) INSL3 increased androstenedione secretion ~2-fold. The CYP17 inhibitor abiraterone abolished androgen secretion and reduced expression of both INSL3 and RXFP2. Collectively, these findings indicate a positive autoregulatory role for INSL3 signaling in maintaining thecal androgen production, and visa versa. Moreover, BMP6-induced suppression of thecal androgen synthesis may be mediated, at least in part, by reduced INSL3-RXFP2 signaling

    Solution structure and novel insights into the determinants of the receptor specificity of human relaxin-3

    Get PDF
    Relaxin- 3 is the most recently discovered member of the relaxin family of peptide hormones. In contrast to relaxin- 1 and - 2, whose main functions are associated with pregnancy, relaxin- 3 is involved in neuropeptide signaling in the brain. Here, we report the solution structure of human relaxin- 3, the first structure of a relaxin family member to be solved by NMR methods. Overall, relaxin- 3 adopts an insulin- like fold, but the structure differs crucially from the crystal structure of human relaxin- 2 near the B- chain terminus. In particular, the B- chain C terminus folds back, allowing Trp(B27) to interact with the hydrophobic-core. This interaction partly blocks the conserved RXXXRXXI motif identified as a determinant for the interaction with the relaxin receptor LGR7 and may account for the lower affinity of relaxin- 3 relative to relaxin for this receptor. This structural feature is likely important for the activation of its endogenous receptor, GPCR135

    Earthquake forecasting in Italy, before and after Umbria-Marche seismic sequence 1997. A review of the earthquake occurrence modeling at different spatio-temporal-magnitude scales.

    Get PDF
    The main goal of this work is to review the scientific researches carried out before and after the Umbria-Marche sequence related to the earthquake forecasting/prediction in Italy. In particular, I focus the attention on models that aim addressing three main practical questions: was (is) Umbria-Marche a region with high probability of occurrence of a destructive earthquake? Was a precursory activity recorded before the mainshock(s)? What was our capability to model the spatio-temporal-magnitude evolution of that seismic sequence? The models are reviewed pointing out what we have learned after the Umbria-Marche earthquakes, in terms of physical understanding of earthquake occurrence process, and of improving our capability to forecast earthquakes and to track in real-time seismic sequences
    corecore