BACKGROUND:To evaluate the feasibility of image-guided radiotherapy based on helical Tomotherapy to spare the contralateral parotid gland in head and neck cancer patients with unilateral or no neck node metastases.METHODS:A retrospective review of 52 patients undergoing radiotherapy for head and neck cancers with image guidance based on daily megavoltage CT imaging with helical tomotherapy was performed.RESULTS:Mean contralateral parotid dose and the volume of the contralateral parotid receiving 40Gy or more were compared between radiotherapy plans with significant constraint (SC) of less than 20Gy on parotid dose (23 patients) and the conventional constraint (CC) of 26Gy (29 patients). All patients had PTV coverage of at least 95% to the contralateral elective neck nodes. Mean contralateral parotid dose was, respectively, 14.1Gy and 24.7Gy for the SC and CC plans (p<0.0001). The volume of contralateral parotid receiving 40Gy or more was respectively 5.3% and 18.2% (p<0.0001)CONCLUSION:Tomotherapy for head and neck cancer minimized radiotherapy dose to the contralateral parotid gland in patients undergoing elective node irradiation without sacrificing target coverage.

Abscisic acid (ABA) has been well defined as an important stress hormone in plants. The signaling pathway of ABA involves a family of pyrabactin resistant-like-1 PYR/PYL/RCAR receptors (PYL receptors) that bind ABA and form a complex with a protein phosphatase 2C (PP2C) family member resulting in downstream signaling events. The ABA receptor family has been well characterized in the model dicot Arabidopsis thaliana and more recently this characterization has branched out into cereals Oryza sativa (rice) and Hordeum vulgare (barley), as well as the monocot model plant Brachypodium distachyon and Fragaria vesca (strawberry). The analysis of these characterized ABA receptors and the use of online databases has allowed the identification of multiple putative ABA receptors in Triticum aestivum (wheat). ABA has been historically called a positive effector. Overexpression of proteins in the ABA signalling pathway or exogenous application of ABA is known to cause an increase in drought, cold, and salt tolerance. More recently ABA has been linked to increased fungal susceptibility in several plants. The role ABA plays in the biotic stress response is still largely unexplored. The focus of this project was to identify and characterize a putative wheat ABA receptor through bioinformatics and an in vitro enzyme activity assay, and use virus induced gene silencing (VIGS) to test what role this receptor plays in fugal susceptibility. A total of 13 putative ABA receptors were located, nine of which are unique between the wheat subgenomes. One receptor TaPYL5.1 was recombinantly expressed, purified, and confirmed as an ABA receptor through a phosphatase based enzyme activity assay. A receptor with high sequence identity to TaPYL5.1, TaPYL5.2A, was targeted for plant trials because the TaPYL5.1 plasmid sequence was codon optimized. A VIGS approach was used to knock down TaPYL5.2A in planta. The TaPYL5.2A knockdown plants were found to have an increased resistance to Fusarium Head Blight progression in the early stages of the disease. In conclusion, wheat ABA receptors were successfully identified and an important correlation between decreased receptor levels and increased early Fusarium Head Blight resistance was found. This correlation however was not easily reproducible due to the severity of coupling VIGS with Fusarium Head Blight, and should be followed up with additional studies looking at the broader family of wheat ABA receptors.

published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

Fusarium head blight (FHB) caused by Fusarium graminearum is a fungal disease of wheat that can result in severe yield losses and contaminate grain with deoxynivalenol (DON). Wheat cultivars with different levels of FHB resistance were combined with fungicides application to control FHB. Results showed that foliar fungicide Prosaro™ combined with moderately resistant cultivars greatly reduced the risk of FHB. Integrating fungicide application with moderately resistant cultivars can be an effective strategy in controlling FHB. Quantitative trait loci (QTL) for resistance to FHB related traits were analyzed using a double haploid population. Four QTL associated with FHB resistance was detected on chromosomes 2B, 2D, 4D and 7A. The QTL on chromosome 2B and 4D were found to reduce multiple FHB-related traits and were more frequently detected than QTL on chromosome 2D and 7A. QTL on chromosome 2B and 4D could be valuable for improving FHB resistance in wheat. / October 2015

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Walking pigeons display a characteristic behaviour: head-bobbing. Head-bobbing consists of two phases, the hold phase during which the head is kept stable in space, and the thrust phase during which the head is quickly moved forward. But why do pigeons and so many other birds head-bob? Two theories have been developed to answer this question. First, head-bobbing may have a visual function, namely object detection during the hold phase and depth perception during the thrust phase. Second, head-bobbing may have the biomechanical function of increasing the stability. The present study aimed to gain further insight into why pigeons head-bob. A gait cycle analysis of walking pigeons revealed that the hold phase starts at a specific point in the gait cycle and is not dependent on the walking speed. The point in the gait cycle at which the hold phase starts indicates a potential increase in stability during the single stance phase, as it leads to a longer period of time during which the center of mass is above the base of support. The end of the hold phase, however, is dependent on the walking speed, specifically the step length for a given walking speed. I found that the thrust phase duration is constant for all walking speeds and the distance the head travels during that time is equal to the step length. With increasing walking speed the head moves faster during the thrust phase and the hold phase duration is decreased leading to a higher head-bobbing frequency. With fast enough walking speed the hold phase is eventually eliminated, marking the transition point from walking with head-bobbing to fast walking without head-bobbing. The exact velocity of this transition point was predicted for each individual and was dependent on the maximal step length of each pigeon. All head-bobbing parameters could be described with the step-frequency, the thrust phase duration, and the maximal step length, indicating that head-bobbing behavior is individual for every pigeon and depends on its body size. / Thesis (Master, Biology) -- Queen's University, 2013-07-22 23:11:41.557

When people interact with each other, they not only listen to what the other says, they react to facial expressions, gaze direction, and head movement. Human-computer interaction would be enhanced in a friendly and non-intrusive way if computers could understand and respond to users’ body language in the same way. This thesis aims to investigate new methods for human computer interaction by combining information from the body language of the head to recognize the emotional and cognitive states. We concentrated on the integration of facial expression, eye gaze and head movement using soft computing techniques. The whole procedure is done in two-stage. The first stage focuses on the extraction of explicit information from the modalities of facial expression, head movement, and eye gaze. In the second stage, all these information are fused by soft computing techniques to infer the implicit emotional states. In this thesis, the frequency of head movement (high frequency movement or low frequency movement) is taken into consideration as well as head nods and head shakes. A very high frequency head movement may show much more arousal and active property than the low frequency head movement which differs on the emotion dimensional space. The head movement frequency is acquired by analyzing the tracking results of the coordinates from the detected nostril points. Eye gaze also plays an important role in emotion detection. An eye gaze detector was proposed to analyze whether the subject's gaze direction was direct or averted. We proposed a geometrical relationship of human organs between nostrils and two pupils to achieve this task. Four parameters are defined according to the changes in angles and the changes in the proportion of length of the four feature points to distinguish avert gaze from direct gaze. The sum of these parameters is considered as an evaluation parameter that can be analyzed to quantify gaze level. The multimodal fusion is done by hybridizing the decision level fusion and the soft computing techniques for classification. This could avoid the disadvantages of the decision level fusion technique, while retaining its advantages of adaptation and flexibility. We introduced fuzzification strategies which can successfully quantify the extracted parameters of each modality into a fuzzified value between 0 and 1. These fuzzified values are the inputs for the fuzzy inference systems which map the fuzzy values into emotional states.

Fusarium head blight (FHB) continues to threaten the economic sustainability of wheat and barley production in Canada and worldwide. The overall goal of this thesis is to expand our current knowledge of the FHB pathogen, Fusarium graminearum and its trichothecene chemotype diversity. Continuous monitoring of trichothecene chemotypes may well inform on the potential risk and the type of Fusarium populations present in a given region. Fusarium populations in Winnipeg and Carman, Manitoba were examined using chemotype as a marker in the field. Rapid expansion of the 3-acetyldeoxynivalenol (3-ADON) chemotype was observed in Winnipeg and Carman. 3-ADON chemotype is consistently found at high frequencies over the previously common 15-acetyldeoxynivalenol (15-ADON) chemotype, suggesting that the shift in pathogen populations is continuing. This study provides the first evidence on the presence of nivalenol (NIV) producing F. cerealis strains in winter wheat in Manitoba, Canada. Therefore, discovery of NIV producing F. cerealis in wheat poses a serious concern for the wheat industry in Canada. Phylogenetic, chemotypic, phenotypic, and pathogenic abilities of 150 strains of F. graminearum species complex (FGSC) from eight countries were investigated. Type and amount of trichothecenes produced by a strain are key factors in determining the level of aggressiveness of that strain regardless of its species origin. The sequence variations of TRI8 gene in different species in the FGSC were examined as Fusarium species may produce different types of trichothecenes depending on differences in the core trichothecene (TRI) cluster genes. The TRI8 haplotypes did group according to chemotype rather than by species, indicating that 3-ADON, 15-ADON and NIV chemotypes have a single evolutionary origin. Comparison of TRI gene expression demonstrated that accumulation of TRI transcripts was higher in 3-ADON producing strains compared to 15-ADON and NIV strains. The presence of masked mycotoxins deoxynivalenol-3-glucoside (D3G) in food and feed is an increasing concern. Canadian spring wheat cultivars inoculated with different chemotypes produce D3G upon Fusarium infection and moderately resistant/intermediate cultivars showed higher D3G/DON ratio compared to susceptible cultivars. / October 2016