Nitrogen flows from several species and varieties of legume

Trial 83C24: N flows from several species and varieties of legume. Trial 83C27: The effect of seeding rate, planting and variety on the residual value of lupins. Trial 84C25: Small rotation trial for 1985. Trial 84C34: Nitrogen response on large rotation plots at ECRS. These trials were carried out in collaboration with: Mr R. Delane, and with assistance from: Mr. T. White, Ms. A. Bishop

Research : co-operation is the new style

Co-operative Research Centres, or CRCs as they are known, are a new trend in agricultural research. Instead of organisations such as Departments of Agriculture or universities pursuing their own individual research projects, sometimes in competition or covering similar fields, the idea is to combine talents and expertise. CRCs were a Federal Government initiative launched in 1990, and the Centre for Legumes in Mediterranean Agriculture was the first involving agriculture in Western Australia

Early sowing of ceral crops in low rainfall areas

One of the objectives of the Department of Agriculture\u27s crop research in the low rainfall, northern wheatbelt is to develop crop varieties and management practices that will make best use of stored water on both sandplain and fine textured soils. Sowing a crop early will improve its water use efficiency and yiel in low rainfall areas

The nitrogen response of wheat crops following lupins

One of the many benefitsof growing narrow-leaved lupins in a crop rotation (Rowland et al 1988) in the increased yield of the following cereal crop as a result of the improved nitrogen level of the soil. This article reports the results from 41 wheat/lupin rotation trials involving a range of nitrogen rates throughout the Western Australian agricultural area between 1978 and 1987. These trials allowed scientists to assess the interaction of nitrogen fertilization with previous cropping history and to estimate some of the contribution of the nitrogen and other effects of lupins within the crop rotations. The results provide some guidelines to help farmers make decisions agout what rates of nitrogen fertiliser to use in a crop rotation with lupins

A consideration of modelling techniques that can be used to evaluate manufacturing strategies

Practising engineers frequently seek to understand what the effects of various manufacturing strategies will be on the performance of their production facilities. In this situation a computer model can help to provide insight and form predictions about future manufacturing system performance. Various types of modelling methods exist and each provide models that have distinct characteristics. This paper presents a review of popular modelling techniques and, based on the results of a structured experimental study, summarises their capabilities to support the evaluation of manufacturing strategies

Attaching NorA efflux pump inhibitors to methylene blue enhances antimicrobial photodynamic inactivation of Escherichia coli and Acinetobacter baumannii in vitro and in vivo

Resistance of bacteria to antibiotics is a public health concern worldwide due to the increasing failure of standard antibiotic therapies. Antimicrobial photodynamic inactivation (aPDI) is a promising non-antibiotic alternative for treating localized bacterial infections that uses non-toxic photosensitizers and harmless visible light to produce reactive oxygen species and kill microbes. Phenothiazinium photosensitizers like methylene blue (MB) and toluidine blue O are hydrophobic cations that are naturally expelled from bacterial cells by multidrug efflux pumps, which reduces their effectiveness. We recently reported the discovery of a NorA efflux pump inhibitor-methylene blue (EPI-MB) hybrid compound INF55-(Ac)en-MB that shows enhanced photodynamic inactivation of the Gram-positive bacterium methicillin-resistant Staphylococcus aureus (MRSA) relative to MB, both in vitro and in vivo. Here, we report the surprising observation that INF55-(Ac)en-MB and two related hybrids bearing the NorA efflux pump inhibitors INF55 and INF271 also show enhanced aPDI activity in vitro (relative to MB) against the Gram-negative bacteria Escherichia coli and Acinetobacter baumannii, despite neither species expressing the NorA pump. Two of the hybrids showed superior effects to MB in murine aPDI infection models. The findings motivate wider exploration of aPDI with EPI-MB hybrids against Gram-negative pathogens and more detailed studies into the molecular mechanisms underpinning their activity

Gram-Negative Bacterial Infection in Thigh Abscess Can Migrate to Distant Burn Depending on Burn Depth

Sepsis remains the major cause of death in patients with major burn injuries. In the present investigation we evaluated the interaction between burn injuries of varying severity and preexisting distant infection. We used Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis) that were genetically engineered to be bioluminescent, which allowed for noninvasive, sequential optical imaging of the extent and severity of the infection. The bioluminescent bacteria migrated from subcutaneous abscesses in the leg to distant burn wounds on the back depending on the severity of the burn injury, and this migration led to increased mortality of the mice. Treatment with ciprofloxacin, injected either in the leg with the bacterial infection or into the burn eschar, prevented this colonization of the wound and decreased mortality. The present data suggest that burn wounds can readily become colonized by infections distant from the wound itself

Sonodynamic inactivation of Gram-positive and Gram-negativebacteria using a Rose Bengal–antimicrobial peptide conjugate

Combating antimicrobial resistance is one of the most serious public health challenges facing society today. The development of new antibiotics or alternative techniques that can help combat antimicrobial resistance is being prioritised by many governments and stakeholders across the globe. Antimicrobial photodynamic therapy is one such technique that has received considerable attention but is limited by the inability of light to penetrate through human tissue, reducing its effectiveness when used to treat deep-seated infections. The related technique sonodynamic therapy (SDT) has the potential to overcome this limitation given the ability of low-intensity ultrasound to penetrate human tissue. In this study, a Rose Bengal–antimicrobial peptide conjugate was prepared for use in antimicrobial SDT (ASDT). When Staphylococcus aureus and Pseudomonas aeruginosa planktonic cultures were treated with the conjugate and subsequently exposed to ultrasound, 5 log and 7 log reductions, respectively, in bacterial numbers were observed. The conjugate also displayed improved uptake by bacterial cells compared with a mammalian cell line (P ≤ 0.01), whilst pre-treatment of a P. aeruginosa biofilm with ultrasound resulted in a 2.6-fold improvement in sensitiser diffusion (P ≤ 0.01). A preliminary in vivo experiment involving ASDT treatment of P. aeruginosa-infected wounds in mice demonstrated that ultrasound irradiation of conjugate-treated wounds affects a substantial reduction in bacterial burden. Combined, the results obtained from this study highlight ASDT as a targeted broad-spectrum novel modality with potential for the treatment of deep-seated bacterial infections

Healing of perforating rat corneal incisions closed with photodynamic laser-activated tissue glue

Background and Objectives Laser-activated photodynamic biologic tissue glues may be useful for closing incisions in ophthalmology. We report on the use of two such preparations to close perforating corneal incisions in living rats. Study Design/Materials and Methods A previously described preparation containing a covalent albumin-chlorin e6 (ce6) conjugate (bovine serum albumin (BSA)–ce6), and a novel mixture of albumin and Janus Green (BSA/JG), both activated with a 665-nm diode laser were used to glue mouse skin ex vivo. The optimized glues were then used to seal incisions in rat corneas and results were compared to control incisions. Rats were sacrificed at day 1, 7, and 14 and eyes tested for leaking pressure and examined histopathologically. Results One day after treatment eyes closed with BSA–ce6 had a leaking pressure (in mmHg) of 357 compared to 193 for control incisions (P<0.01); closure with BSA/JG gave a leaking pressure of 430 (P<0.05 compared to BSA–ce6, and P<0.001 compared to control). Histological examination showed eyes sealed with BSA/JG have less inflammation present than untreated eyes at 7 days. Conclusions These data demonstrate that photodynamic laser activated tissue glues can be used to effectively seal corneal incisions in living animals without thermal damage or undue inflammation