Radiation-induced changes in the export of photoassimilated carbon /|nBarry Jess Shelp. -- 260 0 St. Catharines, [Ont. : s. n.],

Low levels of ionizing radiation induce two translocation responses in soybean: a reduction in photoassimilate export from leaves and a change in the distribution pattern of exported photoassimilate within the plant. In this investigation these responses have been further studied specifically to ascertain the site of radiation damage and to better understand the physiological responses observed. Experimentally the primary data was obtained from studies in which a mature trifoliate leaf of a young soybean plant (Glycine ~ L. cultivar Harosoy '63) is isolated in a closed transparent chamber and allowed to photoassimilate 14C02 for 15 minutes. This is followed by an additional 45 ~_il'1;ute period before the plant is sectl.o ne d an d 14 C-ra dl' oactl.v.l ty d eterml. ne d'l n a 11 parts. Such 14c data provides one with the magnitude and distribution pattern of translocation. Further analyses were conducted to determine the relative levels of the major photosynthetic products using the techniques of paper chromatography and autoradiography. Since differences between control and irradiated P 1 ants were not 0 b serve d l' n t h e par tl't"lo nlng 0 f 14 C between the 80% ethanol-soluble and -insoluble fractions 14 or in the relative amounts of C-products of photosynthesis, the reduction in export in irradiated plants is not likely due to reduced availability of translocatable materials. Data presented in this thesis shows that photoassimilate export was not affected by gamma radiation until a threshold dose between 2.0 and 3.0 krads was reached. It was also observed that radiation-induced damage to the export process was capable of recovery in a period of 1 to 2 hours provided high light intensity was supplied. In contrast, the distribution pattern was shown to be extremely radiosensitive with a low threshold dose between .25 and .49 krads. Although this process was also capable of recovery,lt" occurred much earlier and was followed by a secondary effect which lasted at least for the duration of the experiments. The data presented in this thesis is interpreted to suggest that the sites of radiation action for the two translocation responses are different. In regards to photoassimilate export, the site of action of ionizing radiation is the leaf, quite possibly the process of photophosphorylation which may provide energy directly for phloem loading and for membrane integrity of the phloem tissue* In regards to the pattern of distribution of exported photoassimilate, the site is likely the apical sink, possibly the result of changes of levels of endogenous hormones. By the selection of radiation exposure dose and time post-irradiation, it is possible to affect independently these two processes suggesting that each may be regulated independent of the other and involves a distinct site.

The nature of bullying among secondary school students /

The purpose of this research was to determine the prevalence and effect of bullying in a secondary school. Six hundred and fifty-nine student volunteers completed a survey which included a quantitative component of 40 questions and 3 questions which required a written response. The results suggest that approximately 1 student in 10 was involved in a bullying situation either as a bully or a victim. As age increased, physical bullying decreased whereas psychological remained high in the senior years of high school. Boys were involved more in bullying than girls, especially in the junior years. The effects of bullying could be devastating to the point of school avoidance or early school leaving. The results also indicate that much of the bullying was not being reported. The implication for the education system is that more needs to be done to prevent bullying, to encourage the reporting of bullying, and to deal with the aftermath of a bullying situation.

Transition into the teaching profession: induction and mentoring issues surrounding secondary music teachers /

The purpose of this study was to investigate the issues surrounding the transition into the teaching profession by specifically focusing on teacher induction and mentoring issues while explicitly addressing matters of concern by secondary music teachers in a large suburban school board in southern Ontario. Participants included beginning teachers with fewer than 5 years of teaching, mid career teachers with between 6 and 15 years of instruction, and experienced teachers with more than 16 years of practice. The ' processes of mentoring and inducting new teachers within the board were examined, along with their relationships between proteges, mentors, and administrators. Further, internal and external programs specifically designed and implemented for newer music teachers were scrutinized and discussed. An analysis of key documents and literature on the subject was performed, and data were collected through 16 personal interviews. The findings suggest that although the necessity of mentoring and induction processes has begun to be recognized, there exists a fundamental relationship between mentoring and induction and the effect of the professional attachments to mentoring; the institutional and administrative supports that are enabled; and essential processes and practices between mentors and proteges. Together these three arms combine to support successfiil induction and mentoring initiatives that will help ease the transition into teaching.

The effect of elevated muscle fluid volume on indices of muscle damage following an acute bout of eccentric exercise

The primary purpose of the current investigation was to develop an elevated muscle fluid level using a human in-vivo model. The secondary purpose was to determine if an increased muscle fluid content could alter the acute muscle damage response following a bout of eccentric exercise. Eight healthy, recreationally active males participated in a cross-over design involving two randomly assigned trials. A hydration trial (HYD) consisting of a two hour infusion of a hypotonic (0.45%) saline at a rate of 20mL/minVl .73m"^ and a control trial (CON), separated by four weeks. Following the infusion (HYD) or rest period (CON), participants completed a single leg isokinetic eccentric exercise protocol of the quadriceps, consisting of 10 sets of 10 repetitions with a one minute rest between each set. Muscle biopsies were collected prior to the exercise, immediately following and at three hours post exercise. Muscle analysis included determination of wet-dry ratios and quantification of muscle damage using toluidine blue staining and light microscopy. Blood samples were collected prior to, immediately post, three and 24 hours post exercise to determine changes in creatine kinase (CK), lactate dehydrogenase (LD), interleukin-6 (IL-6) and Creactive protein (CRP) levels. Results demonstrated an increased muscle fluid volume in the HYD condition following the infusion when compared to the CON condition. Isometric peak torque was significantly reduced following the exercise in both the HYD and CON conditions. There were no significant differences in the number of areas of muscle damage at any of the time points in either condition, with no differences between conditions. CK levels were significantly greater 24hour post exercise compared to pre, immediately and three hours post similarly in both conditions. LD in the HYD condition followed a similar trend as CK with 24 hour levels higher than pre, immediately post and three hours post and LD levels were significantly greater 24 hours post compared to pre levels in the CON condition, with no differences between conditions. A significant main effect for time was observed for CRP (p<0.05) for time, such that CRP levels increased consistently at each subsequent time point. However, CRP and IL-6 levels were not different at any of the measured time points when comparing the two conditions. Although the current investigation was able to successfully increase muscle fluid volume and an increased CK, LD and CRP were observed, no muscle damage was observed following the eccentric exercise protocol in the CON or HYD conditions. Therefore, the hypotonic infusion used in the HYD condition proved to be a viable method to acutely increase muscle fluid content in in-vivo human skeletal muscle.

Teachers' perceptions of effects of terminal examinations on teaching and learning at the secondary school level in Zimbabwe

This study was particularly aimed at the examinations and the effect they have on schooling at the secondary school level in Zimbabwe. The views and opinions of teachers on the use of terminal examinations for certification and the influence they are seen to have on teachers' approach to the curriculum were examined. The literature has shown that there is widespread criticism of the justice and effects of terminal examinations. It is argued that they lead to an over-emphasis of that which is measured, knowledge and intellectual ability, at the expense of that kind of education progress which is almost impossible to measure in an end-of-the-course assessment. Three hundred and six secondary school teachers responded to a survey which asked for teachers' perceptions of examinations and the curriculum. The findings of this study indicated that teaching is structured towards examinations. Although teachers are trying to teach and develop reasoning skills and other activities, the pressure of examinations and the importance of doing well in them force teachers to restrict themselves to examination requirements.

The effect of age on the structure and compostition of the cell walls of Choanephora cucurbitarum

The effect of age on the structure and composition of isolated and purified cell walls from cultures of Choanephora cucurbitarum was investigated by microchemical analyses, visible and infrared spectrophotometry, x-ray diffractometry and electron microscopy. Qualitative evaluation revealed the presence of lipids, proteins, neutral sugars, strong alkali soluble sugars, chitin, chitosan and uronic acids in the cell walls of both the 1 and 7 day old cultures. As the mycelium aged, there was a slight but statistically significant increase in the protein content, and a pronounced rise in the chitin and neutral sugar constituents of the cell walls. Conversely, the decrease in the chitosan content during this period had the net effect of altering the chitin: chitosan ratio from near unity in the younger cultures, to a 2:1 ratio in the 7 day old cell wall samples. Glutaraldehyde-osmium fixed thin sections of the 1 day old vegetative hyphae of £. curbitarum revealed the presence of a monolayered cell wall, which upon aging became bilayered. Replicas of acid hydrolysed cell walls demonstrated that both the 1 and 7 day old samples possessed an outer layer which was composed of finely granular amorphous material and randomly distributed microfibrils. The deposition of an inner secondary layer composed of parallel oriented microfibrils in the older hypha was correlated with an increase in the chitin content in the cell wall. The significance of these results with respect to the intimate relationship between composition and structure is discussed.

The effect of gregarine parasite infections, age, and diet on calling song structure and mating behaviour in the Texas field cricket, Gryllus integer

In the past ten years, many researchers have focussed their attention on parasites regarding the role they may play in causing variations in male secondary sexual traits and subsequent effects on female choice. Male age has also been suggested to be an important factor in female choice if old age reflects superior genes. This study investigated the effects that gregarine gut parasites, age, and diet have on the calling and mating behaviour of the male Texas field cricket, Gryllus integer. Male calling songs were recorded in the laboratory using a Digital Signal Processing Network. The song parameters measured were: pulse rate, pulse width, burst duration, pulses per burst, interburst interval, and percent missing pulses. The effects of parasite load and age on the various calling song parameters was investigated in crickets that were fed two different diets varying in nutritional quality. None of the calling song parameters were affected by either parasite load or age in either diet grou p. Courtship behaviour was ob served and recorded using an Eventlog recorder on an IBM computer in the laboratory. Females mated equally with paras(tized and unparasitized males and with old and young males The total duration and proportion of time spent performing each of 9 courtship displays were recorded for males on each diet. Only one display was affected by parasite load. Highly parasitized males fed the nutritionally inferior diet juddered for a proportionately shorter time than males with low parasite loads. Also, older males performed juddering and shaking antennae proportionally longer and juddering and raising wings for longer durations than younger males. Males that successfully mated were observed for performance of 8 post-copulatory guarding behaviour displays. None of the guarding behaviours were affected by parasite load. However, one display was affected by age, with older males performing guard turning for shorter durations than younger males. Results are discuss,ed in terms of the influence of parasites and age on female choice.

The effect of schooling on student self-concept /|nRonald S. Cowley. -- 260 St. Catharines [Ont. : s. n.],

The following research paper was a study into change in student academic and general self-concept with increase in grade level and age# The majority of literature found by this researcher dealt with self-concept and its relationship to achievement and interactions with others, Review, then, was in these two areas-particularily within the academic setting, but outside of it as well. It wrs hypothesized that there would be a decrease in both academic and general student self-concept with increase in grade level and age. Self-Appraisal inventories, measuring general and academic selfconcept, and Inferential Self-Reports, measuring only academic selfconcept, were the instruments used* Subjects were students, Trade 1 to 13, and ranging in age from 5 to 21„ Although al] Self-Appraisal inventories and all Self-1?eports were very similar, they differed according to three Grade levels: Primary (Grades 1 to 3)> Intermediate (Grades L to 8), and Secondary (Grades 9 to 13) • Students in the Primary division received only their respective Self-Appraisal inventory, while others v/ere administered both inventories designed for their grade level. Scores on the inventories were computed to percents and then mean percents were arrived at for epch grade, each of the three grade levels, each age, and each of three age intervals. In all of these instances Spearman1 s rank order coefficients (!lpff) were calculated and significance, at the *05 level, was determined by referring to a table of critical values for one-tailed tests* Similarily fftff scores were computed, but only for individual grades and ages, and significance was determined at the *0b level* In only one instance, the General Dimension for individual grades, was significance of overall decrease found* Consequently the hypotheses put forth did not gain support* The fltff scores, however, revealed some isolated significant changes for the Academic Dimension, which were generally decreases in mean percents from the last grade of one level to the first grade of the next* For age mean percents, significant changes generally took place at early (5 or 6) and late (20 or 21) ages* A number of reasons for the results were presented and were generally based upon the studentfs encounters, or lack of encounters, with achievement or success* No definite conclusions, relevant to the hypotheses stated^ could be made, although a number of isolated ones were drawn on the basis of significant fltff scores* As well, mention was made of the possible trends or tendencies that were revealed by the results, but that could not, or were not, proven significant by "t's11 or "p's"* Teaching methods stressing improvement in academic, as well as socially related, situations, were recommended and a model teaching approach was presented in Appendix B#

Understanding the portfolio in the secondary school classroom

Four secondary school teachers were involved in this case study. Individual interviews, group reflective sessions, and participant portfolios were transcribed verbatim and analyzed. The use of the portfolio in the secondary school classroom was then discussed in relation to emergent themes. These themes included teacher attitude, portfolio structure, portfolio purpose, challenges, effect, and professional development. Teachers were able to individualize the portfolio structure to meet both program and students' needs. The portfolio structure enabled both teachers and students to assume control over the learning process. The portfolio informed teachers about their teaching. This, in tum, challenged them to reflect on their teaching practices and enabled them to redesign curriculum implementation. A collaborative professional development structure fostered a learning environment that enabled teachers to experience success, despite the challenges that they inevitably encountered. These findings were related to contemporary literature. Finally, implications for theory and practice related to portfolio use in the secondary school classroom and professional development for secondary school teachers were considered.

Who expects what from whom? : a gender based study on expectations and secondary school administration

This study is about expectations and aspirations of secondary school teachers. It is an investigation of why some teachers aspire to become administrators and why some teachers do not. My research compares expectations and existing attltudes regarding aspirations toward administration which are held by three distinct groups within the secondary school system: 1) principals/vice-principals, 2) aspiring teachers, and 3) non-aspiring teachers. This study questions why, in the late 60's, secondary school administration is still predominated by men. The conclusions and recommendations were based on interviews with thirty men and women in the Hamilton Secondary School System. In addltion, Mr. Keith Rielly, Superintendent of Operations, made valuable contributions to my work. The interviews revealed experiences and percept ions of men and women in di scourse about f amil y re lat i onshi ps, educational choices and perceived internal and external barriers which inhiblted or enhanced their decision to aspire to secondary school administration. Candidates spoke about their personal and professional Hves wlth respect to encouragement, perceived images of an administrator, netWOrking and the effect of marriage and children on their careers. Historically, women have not accepted the challenge of administration and It would appear as if this is still the case today. My research suggests that women are under-represented in secondary school administration because of internal and external barriers which discourage many women from aspiring. I conclude that many of women's internal barrlers are reinforced by external roadblocks which prevent women from aspiring to secondory school administration. Thus. many women who do not envision a future in educational administration establish priorities outside the general realm of education. I recommend that males and females recognize that women make valuable contributions to educational theory and design based on their experiences which may be "differene from mole experiences. but just as significant. Mole and female representation in secondary school administration represents a balance between attitudes and behaviours which can not be accomplished when an administrative offlce is dominated by on all ma1e or all female staff.

Cognitive set, absorption, and achievement as moderators of the perceptual closure effect in picture priming /

The present study examined individual differences in Absorption and fantasy, as well as in Achiievement and achievement striving as possible moderators of the perceptual closure effect found by Snodgrass and Feenan (1990). The study also examined whether different instructions (experiential versus instrumental) interact with the personality variables to moderate the relationship between priming and subsequent performance on a picture completion task. 1 28 participants completed two sessions, one to fill out the MPQ and NEO personality inventories and the other to complete the experimental task. The experimental task consisted of a priming phase and a test phase, with pictures presented on a computer screen for both phases. Participants were shown 30 pictures in the priming phase, and then shovm the 30 primed pictures along with 30 new pictures for the test phase. Participants were randomly assigned to receive one of the two different instruction sets for the task. Two measures of performance were calculated, most fragmented measure and threshold. Results of the present study confirm that a five-second exposure time is long enough to produce the perceptual closure effect. The analysis of the two-way interaction effects indicated a significant quadratic interaction of Absorption with priming level on threshold performance. The results were in the opposite direction of predictions. Possible explanations for the Absorption results include lack of optimal conditions, lack of intrinsic motivation and measurement problems. Primary analyses also revealed two significant between-subject effects of fantasy and achievement striving on performance collapsed across priming levels. These results suggest that fantasy has a beneficial effect on performance at test for pictures primed at all levels, whereas achievement striving seems to have an adverse effect on performance at test for pictures primed at all levels. Results of the secondary analyses with a revised threshold performance measure indicated a significant quadratic interaction of Absorption, condition and priming level. In the experiential condition, test performance, based on Absorption scores for pictures primed at level 4, showed a positive slope and performance for pictures primed at levels 1 and 7 based on Absorption showed a negative slope. The reverse effect was found in the instrumental condition. The results suggest that Absorption, in combination with experiential involvement, may affect implicit memory. A second significant result of the secondary analyses was a linear three-way interaction of Achievement, condition and priming level on performance. Results suggest that as Achievement scores increased, test performance improved for less fragmented primed pictures in the instrumental condition and test performance improved for more highly fragmented primes in the experiential condition. Results from the secondary analyses suggest that the revised threshold measure may be more sensitive to individual differences. Results of the exploratory analyses with Openness to Experience, Conscientiousness and agentic positive emotionality (PEM-A) measures indicated no significant effects of any of these personality variables. Results suggest that facets of the scales may be more useful with regard to perceptual research, and that future research should examine narrowly focused personality traits as opposed to broader constructs.

Orientation of Non-Native 2-Monosubstituted and 2,3-Disubstituted 1,4-Naphthoquinones in the A1 binding site of PSI and the effect on the rate of electron transfer : an electron paramagnetic resonance spectroscopy study

The proce-ss ofoxygenic photosynthesis is vital to life on Earth. the central event in photosynthesis is light induced electron transfer that converts light into energy for growth. Ofparticular significance is the membrane bound multisubunit protein known as Photosystem I (PSI). PSI is a reaction centre that is responsible for the transfer of electrons across the membrane to reduce NADP+ to NADPH. The recent publication ofa high resolution X-ray structure of PSI has shown new information about the structure, in particular the electron transfer cofactors, which allows us to study it in more detail. In PSI, the secondary acceptor is crucial for forward electron transfer. In this thesis, the effect of removing the native acceptor phylloquinone and replacing it with a series of structurally related quinones was investigated via transient electron paramagnetic resonance (EPR) experiments. The orientation of non native quinones in the binding site and their ability to function in the electron transfer process was determined. It was found that PSI will readily accept alkyl naphthoquinones and anthraquinone. Q band EPR experiments revealed that the non-native quinones are incorporated into the binding site with the same orientation of the headgroup as in the native system. X band EPR spectra and deuteration experiments indicate that monosubstituted naphthoquinones are bound to the Al site with their side group in the position occupied by the methyl group in native PSI (meta to the hydrogen bonded carbonyl oxygen). X band EPR experiments show that 2, 3- disubstituted methyl naphthoquinones are also incorporated into the Al site in the same orientation as phylloquinone, even with the presence of a halogen- or sulfur-containing side chain in the position normally occupied by the phytyl tail ofphylloquinone. The exception to this is 2-bromo-3-methyl --.- _. -. - -- - - 4 _._ _ _ - _ _ naphthoquinone which has a poorly resolved spectrum, making determination of the orientation difficuh. All of the non-native quinones studied act as efficient electron acceptors. However, forward electron transfer past the quinone could only be demonstrated for anthraquinone, which has a more negative midpoint potential than phylloquinone. In the case of anthraquinone, an increased rate of forward electron transfer compared to native PSI was found. From these results we can conclude that the rate ofelectron transfer from Al to Fx in native PSI lies in the normal region ofthe Marcus Curve.

The Effect of Skate Blade Radius of Contour and Radius of Hollow on Skating Performance in Male Ice Hockey Players

The primary purpose of this study was to investigate the effect of skate blade shape on skating performance. A secondary purpose was to evaluate if a change in hollow shape can create additional effects on skating performance. Thirty-seven male ice hockey players (age=18 years, SD=3.4) participated. The intervention consisted of four sharpening trials assessed using three on-ice tests. Participant feedback was also assessed using a Likert scale questionnaire. Statistical analysis included within-subject repeated measures MANOVA of trial by skating variables (p≤0.05). Results revealed Contour 1 enhanced performance compared to baseline on six variables at varsity level and five variables at midget level. Contour 1 enhanced performance compared to Contour 2 on six variables at the varsity and midget levels. Contour 1 also scored highest on the feedback questionnaire. Findings of this study indicate that contouring is a necessary practice to achieve optimal skating performance.

Defence of Agaricus bisporus against toxic secondary metabolites from Trichoderma aggressivum.

Trichoderma spp are effective competitors against other fungi because they are mycoparasitic and produce hydrolytic enzymes and secondary metabolites that inhibit the growth of their competitors. Inhibitory compounds produced by Trichoderma aggressivum, the causative agent of green mold disease, are more toxic to the hybrid off-white strains of Agaricus bisporus than the commercial brown strains, consistent with the commercial brown strain’s increased resistance to the disease. This project looked at the response of hybrid off-white and commercial brown strains of A. bisporus to the presence of T. aggressivum metabolites with regard to three A. bisporus genes: laccase 1, laccase 2, and manganese peroxidase. The addition of T. aggressivum toxic metabolites had no significant effect on MnP or lcc1 transcript abundance. Alternatively, laccase 2 appears to be involved in resistance to T. aggressivum because the presence of T. aggressivum metabolites results in higher lcc2 transcript abundance and laccase activity, especially in the commercial brown strain. The difference in laccase expression and activity between A. bisporus strains was not a result of regulatory or coding sequence differences. Alteration of laccase transcription by RNAi resulted in transformants with variable levels of laccase transcript abundance. Transformants with a low number of lcc transcripts were very sensitive to T. aggressivum toxins, while those with a high number of lcc transcripts had increased resistance. These results indicated that laccase activity, in particular that encoded by lcc2, serves as a defense response of A. bisporus to T. aggressivum toxins and contributes to green mold disease resistance in commercial brown strains.