Experiments in the control of bacterial wilt of tomatoes in south-eastern Queensland

Under the conditions of the experiment, treatment of the soil with sulphur to produce a pH value of 4, followed by the addition of lime to restore the pH value to 5, failed to give efficient control of bacterial wilt in tomatoes. Varietal trials on infested soil showed that Break O' Day, which is widely grown locally, was very susceptible to the disease. Strains of another Australian variety, Sensation, and several varieties from the United States of America, showed promise of possessing some degree of resistance

Investigations on the phytotoxicity of Bordeaux mixture to tomatoes

Bordeaux mixture (4-4-40) was shown in a series of experiments to have a higher toxicity for the tomato plant than Bordeaux 4-2-40 and various "inert" copper compounds. Experimental results indicated that the lime content of Bordeaux mixture is an important factor in phytotoxicity to tomatoes. The evidence obtained suggests that Bordeaux mixture adversely affects transpiration, photosynthesis and translocation, and through the general physiological upset impairs flower setting. A new method of estimating phytotoxicity was devised and is described in detail

Radionuclide and heavy metal sorption on to functionalised magnetic nanoparticles for environmental remediation

The presence of radionuclides and heavy metal ions in aqueous waste streams from industrial processes, especially in the nuclear waste industry, are a major concern. Many other processes are inherent producers of hazardous aqueous waste streams that require treatment for further disposal. These wastes quite often contain many contaminants, from harmful to very toxic. Contact with the environment, through groundwater or rivers, with such contaminants needs to be avoided. The ability to selectively sequester and remove contaminants from aqueous wastes with high loading capacities is of paramount importance to achieve full removal of the contaminants produced in many industries. The recent development of phosphate functionalised superparamagnetic magnetite ((PO)x-Fe3O4) nanoparticles have been shown to have ultra-high loading capacities and a high degree of selectivity towards uranium (U(VI)). The ability to manipulate these NPs with an external magnetic field gives these nanomaterials an advantage over many other conventional technologies in the field. These low-cost, non-toxic, and easily prepared magnetic NPs are highly biocompatible and have already been widely applied in the biotechnology and biomedical industries. The addition of specific functionalities allows for the fine tuning of the selectivity towards certain elements, therefore allowing full control over the selective removal of a wide range of contaminants. This study addresses the optimisation of the NPs manufacturing process that allows for the use of these NPs in a wider range of environments. Many of these waste streams are extreme environments, where they can be highly acidic or highly basic conditions. Therefore the feasibility of coating the Fe3O4 with silica (SiO2) was addressed, to provide an acid resistant layer and substrate for further functionalisation. Both the silica coating, and the applied surface functionality, were found to be stable against dissolution or chemical changes under acidic conditions from pH 1-4. Once acid resistance was established, the ability to extract a wide range of contaminant ions was also investigated. Sorption experiments with a wide range of contaminant ions were conducted to determine the selectivity and loading capacities of both (PO)x-Fe3O4 and (PO)x-SiO2@Fe3O4 NPs, at acidic (pH 3), neutral (pH 7), and basic (pH 11) conditions. Providing a basis for the manufacture of a state-of-the-art, novel extraction tool for both heavy metals and radionuclides. Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy - Energy Dispersive X-Ray (STEM-EDX) were used to achieve full characterisation of the NP complexes and supernatants to determine the successful extraction and presence of the contaminant metal ions used in this study. Determining the uptake kinetics, loading capacities for Cs(I), K(I), Na(I), Ca(II), Cd(II), Co(II), Cu(II), Mg(II), Mn(II), Mo(II), Ni(II), Pb(II), Sr(II), Al(III), Ce(III), Cr(III), Eu(III), Fe(III) and La(III) on to (PO)x-Fe3O4 and (PO)x-SiO2@Fe3O4 NPs. Implications of the use of these NPs in the extraction of radionuclides and heavy metals have been discussed in each case along with the potential for developing a broad-spectrum adsorbent. In conclusion, this PhD has shown the potential of these novel as-synthesised phosphate functionalised NP complexes to be utilised for heavy metal and radionuclide extraction, of a range of contaminants, from aqueous solutions, in acidic, neutral, and basic conditions. The production of these cost-effective and selective nanomaterials which exhibit rapid kinetics has the potential to be an important asset to the water treatment industry. Overall, these NP-complexes have been effective in fully removing a wide range of heavy metal contaminants and, therefore, have shown great promise to become a broad-spectrum adsorbent tool, which ultimately will aid in the clean-up of many new and legacy waste environments.Open Acces

Perivascular nerves: Changes in ageing and disease

This thesis presents a study of the changes in perivascular catecholamine(CA)- and peptide-containing nerves of peripheral and central blood vessels during ageing, after sympathectomy, in diabetes and atherosclerosis and after acrylamide poisoning. Histochemical changes in innervation on blood vessels during ageing was studied in rats and rabbits and assessed qualitatively and quantitatively using image analysis. The density of CA-containing and neuropeptide Y-immunoreactive (NPY-IR) nerve fibres did not change in either species over the ages studied. In rabbits, fine, varicose, calcitonin gene-related peptide (CGRP)-IR nerve fibres decreased with age while vasoactive intestinal polypeptide (VIP)- and substance P (SP)-IR nerve fibres showed increased with age. In rats, the density of VIP-IR nerve fibres could not be seen to change however, CGRP- and SP-IR nerve fibres increased steadily with age. Quantitative measurements revealed that both CGRP- and SP-IR nerve fibres increase similarly until 12 months of age then SP-IR nerve fibres begin to decrease while CGRP-IR nerve fibres continue to increase in number. Vascular innervation patterns were also studied in two other species. The sheep middle cerebral artery was shown to have dense plexuses of VIP-IR, CGRP-IR and CA-containing nerves. CA-containing, NPY-, CGRP-, VIP- and SP-IR perivascular nerves were revealed in the guinea pig spiral modialor artery of the inner ear; CGRP- and SP-IR were colocalized. Sympathectomy by chronic treatment of young and mature rats with guanethidine led to large increases in CGRP-IR nerves in blood vessels while CA and NPY-IR nerves were virtually abolished. SP-IR nerves were unchanged. VIP-IR nerves were unchanged when young rats were treated with guanethidine, but showed in increase when adults were treated. Sympathectomy by treatment of neonatal rats with antibodies to nerve growth factor (NGF) produced decreases in CGRP- and SP-IR nerves as well as CA-containing and NPY-IR nerves, but VIP-IR nerve fibres were unchanged. Since by 8 weeks of age NPY-IR but not CA-containing nerves were found to reinnervate the mesenteric artery, the likelihood that NPY-containing non-sympathetic nerves are involved is proposed. The neuropathies caused by diabetes and acrylamide poisoning in rats and by atherosclerosis in rabbits have been studied. In both diabetes and acrylamide poisoning CA-containing, NPY-, CGRP- and SP-IR nerves were decreased and the nerves often showed structural damage. However, VIP-IR nerves increased slightly in diabetic vessels, but decreased after acrylamide poisoning. Atherosclerotic vessels showed little change in perivascular innervation patterns except for a slight decrease in SP- and CGRP-IR nerve densities

Is This State Really a Closed Society?

Editorial expressing agreement with James Silver\u27s description of Mississippi as a \u27closed society\u27; Source: Aberdeen Examiner (Miss.); Unknown datehttps://egrove.olemiss.edu/jws_clip/1034/thumbnail.jp

Current conservation policies in the UK and Ireland overlook endangered insects and are taxonomically biased towards Lepidoptera

Funding statement This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Acknowledgements We would like to acknowledge Dr Jeff Ollerton and the two anonymous reviewers for their helpful comments on the original version of this manuscript.Peer reviewedPublisher PD

Economic evaluation of laparoscopic surgery for colorectal cancer

Objectives: To assess the cost-effectiveness of laparoscopic surgery compared with open surgery for the treatment of colorectal cancer. Methods: A Markov model was developed to model cost-effectiveness over 25 years. Data on the clinical effectiveness of laparoscopic and open surgery for colorectal cancer were obtained from a systematic review of the literature. Data on costs came from a systematic review of economic evaluations and from published sources. The outcomes of the model were presented as the incremental cost per life year gained and using cost-effectiveness acceptability curves (CEACs) to illustrate the likelihood that a treatment was cost-effective at various threshold values for society’s willingness to pay for an additional life year. Results: Laparoscopic surgery was on average £300 more costly and slightly less effective than open surgery and had a 30% chance of being cost-effective if society is willing to pay £30,000 for a life year. One interpretation of the available data suggests equal survival and disease-free survival. Making this assumption, laparoscopic surgery had a greater chance of being considered cost-effective. Presenting the results as incremental cost per quality adjusted life year (QALY) made no difference to the results, as utility data were poor. Evidence suggests short-term benefits following laparoscopic repair. This benefit would have to be at least 0.01 of a QALY for laparoscopic surgery to be considered cost-effective. Conclusions: Laparoscopic surgery is likely to be associated with short-term quality of life benefits, similar long-term outcomes and an additional £300 per patient. A judgement is required as to whether the short-term benefits are worth this extra cost.Peer reviewedAuthor versio