A bioeconomic model for determining the optimal response to a new weed incursion in Australian cropping systems

Invasions by non-indigenous plant species pose serious economic threats to Australian agricultural industries. When an invasion is discovered a decision has to be made as to whether to attempt to eradicate it, contain it or do nothing. These decisions should be based on long term benefits and costs. This paper describes a bioeconomic simulation framework with a mathematical model representing weed spread linked to a dynamic programming model to provide a means of determining the economically optimal weed management strategies over time. The modelling framework is used to evaluate case study invasive weed control problems in the Australian grains industry.weeds, incursion, bioeconomic model, Crop Production/Industries, Research Methods/ Statistical Methods,

Radial consolidation equation with variable load, material and drain efficiency parameters

Numerous complex analytical solutions are available for analysis of consolidation problems involving radial drainage, yet the most common solution used for determining the rate of consolidation is the equal strain solution presented by Hansbo (1981). Maintaining the simplicity of Hansbo’s (1981) solution this paper presents radial consolidation equations that capture the versatility of the more complex methods. Material and geometry properties vary piecewise-constant with time while loading/unloading varies piecewise-linear with time. A new drain efficiency parameter is introduced to model the detrimental effects of drain clogging and kinking. Drain clogging/kinking is simulated by specifying the excess pore pressure in the drain, normally set to zero, as a fraction of the average excess pore pressure in the soil. The new equations are easily implemented in a spreadsheet or computer program providing a simple yet versatile tool for analysis of consolidation problems dominated by radial drainage. Computer code for implementing the new approach in a Microsoft Excel is provided

Presumed choroidal metastasis from soft tissue myoepithelial carcinoma

Purpose: To report a case of presumed choroidal metastasis from soft tissue myoepithelial carcinoma and highlight challenges in its diagnosis. Observations: A 52-year-old man was referred with a two-week history of photopsia in his left eye. His background medical history included known soft tissue myoepithelial carcinoma metastatic to his bone, lung, liver and chest wall. A large, raised, yellow choroidal lesion was identified nasal to and abutting the optic disc. This lesion demonstrated growth 1 month after presentation. The patient died with widespread metastatic disease 5 months after initial presentation. Conclusion and importance: Soft tissue myoepithelial carcinoma can rarely metastasise to the choroid and present as a rapidly-growing, yellow, echodense tumour with serous retinal detachment. MRI brain can assist in tumour evaluation and monitoring progression, while immunoperoxidase stains and molecular testing can assist with diagnosis. The condition has an aggressive natural history and poor prognosi

Coherent Excitonic Coupling in an Asymmetric Double InGaAs Quantum Well Arises from Many-Body Effects

We study an asymmetric double InGaAs quantum well using optical two-dimensional coherent spectroscopy. The collection of zero-quantum, one-quantum, and two-quantum two-dimensional spectra provides a unique and comprehensive picture of the double well coherent optical response. Coherent and incoherent contributions to the coupling between the two quantum well excitons are clearly separated. An excellent agreement with density matrix calculations reveals that coherent interwell coupling originates from many-body interactions

Deubiquitylating enzymes and disease

Deubiquitylating enzymes (DUBs) can hydrolyze a peptide, amide, ester or thiolester bond at the C-terminus of UBIQ (ubiquitin), including the post-translationally formed branched peptide bonds in mono- or multi-ubiquitylated conjugates. DUBs thus have the potential to regulate any UBIQ-mediated cellular process, the two best characterized being proteolysis and protein trafficking. Mammals contain some 80–90 DUBs in five different subfamilies, only a handful of which have been characterized with respect to the proteins that they interact with and deubiquitylate. Several other DUBs have been implicated in various disease processes in which they are changed by mutation, have altered expression levels, and/or form part of regulatory complexes. Specific examples of DUB involvement in various diseases are presented. While no specific drugs targeting DUBs have yet been described, sufficient functional and structural information has accumulated in some cases to allow their rapid development