Aspects of seed transfer within a direct drilling coulter (opener) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Agricultural Mechanisation at Massey University

A number of laboratory and field experiments were conducted in order to identify and quantify seed and seedling spacing variations produced by an experimental direct drill. Seed contact with both stationary and moving components of the coulter assembly was considered to contribute to the increased variability of seed spacing that resulted from the positioning of a chisel direct drilling coulter beneath a "Nodet Gougis" seed selection mechanism. Alternatives for transferring the seeds from the seed selection mechanism to the soil were considered. The simplest of these alternatives, a seed-transfer tube, was tested in a number of different shapes and positions. It was found that the seeder required modifications to its release characteristics in order to satisfactorily incorperate the tube transfer system. A number of deflector plates were fitted to the seeder to control seed release trajectory. A 40 degree seed deflector plate was found to produce a seed path that was most compatible with a straight vertical seed-transfer tube. A video recording technique was used to assess the effects of seeder modifications on seed release trajectory. The modified seeder and the tube transfer system were combined with the chisel direct drilling coulter, and seed spacing performance was retested. Seed spacing variability was found to be considerably less than with the original experimental drill in the laboratory, although field performance was not improved to the same extent. It was considered that this effect may have been attributable to the effects of soil flow with the direct drilling coulter and the manner with which the seed was released into the soil, which differed with the tube system compared with the unmodified coulter tested initially

Multiple differences in calling songs and other traits between solitary and gregarious Mormon crickets from allopatric mtDNA clades

The Linnaean Society, The British Ecological Society, The Russell Trust (St. Andrews), The Orthopterists' Society and an NSERC (Canada) grant to DTG. Gordon S. Brown provided assistance with digital imaging and morphological measurements.Background: In acoustic species, traits such as male calling song are likely to diverge quickly between allopatric populations due to sexual selection, and divergence in parameters such as carrier frequency, chirp structure, and other important song characters can influence sexual isolation. Here we make use of two forms of Mormon crickets to examine differences in a broad suite of traits that have the potential to influence speciation via sexual isolation. Mormon crickets in "gregarious" populations aggregate into dense migratory bands, and females are the sexually competitive Fsex ( sex- role reversal). There is also a non-outbreak "solitary" form. These two forms are largely but not perfectly correlated with a significant mtDNA subdivision within the species that is thought to have arisen in allopatry. Combined information about multiple, independently evolving traits, such as morphology and structural and behavioural differences in calling song, provides greater resolution of the overall differences between these allopatric populations, and allows us to assess their stage of divergence. We test two predictions, first that the forms differ in song and second that gregarious males are more reluctant to sing than solitary males due to sex role reversal. We also tested for a difference in the relationship between the size of the forewing resonator, the mirror, and carrier frequency, as most models of sound production in crickets indicate that mirror size should predict carrier frequency. Results: Multivariate analyses showed that solitary and gregarious individuals from different populations representing the two mtDNA clades had almost non-overlapping distributions based on multiple song and morphological measurements. Carrier frequency differed between the two, and gregarious males were more reluctant to sing overall. Mirror size predicted carrier frequency; however, the relationship between mirror size and surface area varied between solitary and gregarious forms, suggesting that factors above and beyond mirror size contribute to carrier frequency. Conclusion: The two clades of Mormon crickets differ in a broad suite of independent traits that probably justify subspecies status ( the two can successfully mate so may not be reproductively isolated). However, our results emphasize the importance of carefully distinguishing the ultimate causation of differences between traits used to delineate species or subspecies boundaries.Publisher PDFPeer reviewe

William Ritchie to Mr. Meredith (5 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1994/thumbnail.jp

The Fate of Chlorpropham With Particular Reference to Its Use as a Potato Sprout Suppressant

This thesis examines the fate of chlorpropham when applied to stored potatoes to suppress sprouting. Throughout this project the work concentrated on the use of chlorpropham in potato processors' stores and in particular crisp manufacturers' stores since these are operated in a consistent manner and the largest proportion of the sprout suppressant formulation of chlorpropham is used in these stores. The fate of chlorpropham was investigated in two distinct areas. The portion of the applied chlorpropham that ends up in the crisps as a residue is the first area, while investigation of the possible biotransformation products of chlorpropham produced by three potato pathogens is the second. A sensitive analytical method for the determination of chlorpropham residues in crisps was developed using acetonitrile as extracting solvent followed by an oil reducing step which was essentially a counter-current separation of chlorpropham and co-extracted oil with final quantification by gas chromatography (GC) or high performance liquid chromatography (HPLC). Recovery from crisp samples spiked with chlorpropham was 93.2%+/-6.37 and the minimum detectable amount was 0.035 mug/g when the GC was used. When the HPLC was the instrument used to quantify the residues then a minimum of 0.02 mug/g could be detected and quantified. A chlorpropham residue of 0.45 mug/g was detected in crisps produced from slices originally containing a 0.18 mug/g residue. Chlorpropham contamination of untreated material resulted after frying in friers which had been previously processing chlorpropham treated material. The existing literature concerning the transformation of chlorpropham is reviewed in Chapter 2, with particular reference to potatoes and potato storage situations although little information was available on the fate of chlorpropham that is applied to this staple food. Radiolabelled chlorpropham that had been synthesised by Isabel Boyd in this department was purified using an alumina clean-up column and made ready for use in the biotransformation studies. Erwinia carotovora var. atroseptica (bacterial soft rot), Polyscytalum pustulans (skin spot) and Phoma exigua var. foveata (gangrene) were grown on standard growth media apart from the fact that labelled chlorpropham had been incorporated into the media. The E. carotovora var. atroseptica, a facultative anaerobe, was cultured under both aerobic and anaerobic conditions. Complete recovery of the medium incorporated radiolabel as unaltered chlorpropham was observed. In the P. pustulans study complete recovery of the radiolabel was not achieved. Unaltered chlorpropham contained all of the label that was extracted, but since only incomplete recovery of the applied radiolabel was achieved then it is invalid to state that no metabolites were produced. In the metabolism study of the P. exigua var. foveata, more complete recoveries of the radiolabel from the cultures were accomplished and a water soluble metabolite was detected. Characterisation of this metabolite was not possible but some solvent partitioning characteristics were identified as were its chromatographic behaviour on HPLC

Functional Nanocomposite Surfaces for Antibacterial, Oil–Water Separation, and Optical Applications

Surface functionalisation can be used to modify the interaction between liquids and solid surfaces which is of importance in many applications such as self-cleaning, anti-fouling, and anti-fogging. The use of nanocomposite materials also provides a way of improving particular properties of the film even when small amounts of nano-material is used. The use of nanocomposite coatings to tailor the wettability, as well as to incorporate additional properties into surface coatings has been studied in this thesis for antibacterial, oil–water separation, and optical applications. Chapter 1 provides an introduction to nanocomposite coatings including a brief review of how they are prepared and for what applications they are used. Chapter 2 provides information on how surface wettability is measured as well as summarising the other experimental techniques used throughout this thesis. Chapter 3 describes the application of polymer–nanoparticle–fluorosurfactant complex nanocomposite coatings for antibacterial oil–water separation applications. Porous substrates coated with these polymer–nanoparticle–fluorosurfactant complex nanocomposite coatings are found to readily separate oil–water mixtures under both static and continuous flow as well as displaying antibacterial surface properties against Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). A key advantage of this approach for coating substrates is its single-step simplicity. Potential applications include provision of safe drinking water, environmental pollution clean-up, and anti-fogging. Chapter 4 utilises a single-step, low temperature, solventless atomised spray plasma deposition technique for the preparation of antibacterial polymer–metallosurfactant nanocomposite coatings which are highly active against both Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). Chapter 5 extends the use of the atomised spray plasma deposition technique into optical applications with the preparation of high refractive index hybrid polymer and polymer–inorganic nanocomposite coatings. Refractive indices as high as 1.936 at 635 nm wavelength have been obtained for 4-bromostyrene / toluene + TiO2 layers using very low titania loadings (8% w/v). Thin films with any desired refractive index up to 1.936 can be easily deposited by varying the precursor mixture composition

Taxonomy and DNA Barcoding in the Genus Manfreda (Salisb.) Asparagaceae

The genus Manfreda Salisb. of Asparagaceae is a genus of potential horticultural interest and is currently subject to breeding efforts at the University of Arkansas. A lack of taxonomic clarity however undermines the classification of potential inter - and intrageneric hybrids. The study aims to assess existing species delimitation within the genus Manfreda employing morphology while investigating the potential utility of Consortium for the Barcode of Life Plant (CBOL) DNA Barcodes for identification of specific taxa and an External Transcribed Spacer (ETS) - Internal Transcribed Spacer (ITS) DNA barcode for developed hybridized taxa. Observation of 855 herbarium specimens facilitated phylogenetic and Principal Component Analysis of morphology. Phylogenetic analysis employing Maximum Parsimony and Bayesian techniques of qualitative characters failed to identify any interspecific relationships with sufficient confidence. Principal Component Analysis identified 14 species exhibiting uniformity in categorical characters. The residual seven were subjected to further review employing existing literature, biogeographical and morphological data from herbarium specimens. The study supported specific designations of 19 of 21 species studied. A proposal for Manfreda pubescens (Regel & Ortgies) Verh.-Will. ex Espejo & López-Ferr. to be relegated to a varietal rank of Manfreda maculata (Mart) Rose was concluded based on a lack of consistent derived characters as well as biogeographical and ecological continuity. Utility of the CBOL Plant DNA Barcode for identification of Manfreda species was investigated employing phylogenetic and nucleotide networking techniques. The CBOL Plant DNA Barcode failed to identify any interspecific relationships via Maximum Parsimony or Bayesian techniques. Sufficient variation however was available for differentiation of each species of Manfreda via composition of a nucleotide network map. Results allude to minimal divergence between species of Manfreda, yet sufficient derived characters for functionality of CBOL Plant DNA Barcodes. Analysis of an ETS - ITS DNA barcode for identification of intergeneric hybridized taxa of Agave L., Manfreda and Polianthes L. could not be conducted due to inefficiencies in DNA amplification techniques. The ETS gene region could not be amplified, a trial of three different amplification parameters was conducted and a lack of appropriate PCR primers was identified as the cause of no amplification. Amplification of the ITS gene region was successfully achieved; however, subsequent analysis of the electropherogram alluded to intra-individual polymorphisms within the genome. Therefore,it was concluded that the utility of the ITS region is negligible for DNA barcoding of the maag 01-07-13, mapo 01-04-07 and mapo 05-04-02 intergeneric hybrids

Cerebral involvement in head injury. A study based on the examination of two hundred cases

It is difficult to summarise the points which have been discussed in this thesis. The study of the two hundred cases dealt with has provided a large mass of material for investigation, of which only certain aspects have been analysed. My plan has been to record the facts and to discuss them throughout the text. The frequency with which the common symptoms and signs of concussion occur has been analysed, and their significance discussed. Changes in the pressure, cytology,and chemistry of the cerebro-spinal fluid have been investigated in a series of severe cases, and this has thrown light on the significance of certain symptoms and signs of the acute stage. The mechanism by which the brain is damaged in head injury has been discussed, and conclusions have been arrived at with regard to the mechanism of loss of consciousness and contre -coup injury. The pathology of the condition called "cerebral irritation" has also been considered. The conclusions arrived at in this section of the thesis are quite contrary to most current teaching. The cases in GROUP C provided material for study of the stages by which consciousness returns. I have been unable to find any record in the literature of an analysis of the clinical features of the acute stage of head injury in any large series such as is here attempted. Further special importance attaches to this work from the fact that most of the cases have not only been examined in the acute stage, but have been re- examined at an interval after discharge. The fact that, in the series, compensation cases are few in number has greatly added to the value of this part of the work. The frequency with which post-concussional disturbances occur has been investigated. It has become quite apparent that physical examination is of little value in the attempt to estimate the degree of cerebral damage, and hence the detailed analysis of the features of genuine post-concussional disturbances of a subjective nature has been of great importance. From the study of the post- concussional symptoms in a series of cases, I claim to have shown that these have well defined features which must be regarded as having an organic basis. This conclusion has been based on the clinical study alone, but is found to correspond with the opinion of some recent workers who have been investigating the pathological changes which occur in these cases. The investigation of post-mortem material forms only a small section of this work, but I have succeeded in demonstrating changes in the neuroglia . which have previously only been described in experimental work. Finally, the practical application of certain aspects of this work has been discussed in relation to diagnosis, prognosis and treatment, and the methods of examination which I have found useful have been described. The subject of this thesis suggests many lines of investigation, and the work which is here recorded must be regarded merely as a preliminary report based on the first two hundred cases seen

Correlation Analysis of Simultaneously Collected Bistatic and Monostatic Sea Clutter

In this work we analyse the correlation properties of simultaneous bistatic and monostatic polarimetric sea clutter data, collected by the NetRAD multistatic radar system. In particular, we study the temporal autocorrelation and cross-correlation functions of the texture and speckle samples, as a function of the system geometry and of the polarization of the transmitter and receiver antennas. These features can vary significantly as a function of bistatic angle and the goal of this paper is to quantify these variations and extract any trends that are observed