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Fat subtraction protocol for wide-angle x-ray scatter analysis of breast biopsies
No full textBreast cancer detection often involves the use of mammography to locate sus-
picious lesions followed by extraction of some tissue within the lesion via a biopsy
procedure. The gold standard method for determining whether the extracted tis-
sue is malignant or benign is an histological analysis. However, complimentary x
ray methods such as x-ray
uorescence (XRF), small-angle x-ray scatter (SAXS) and
wide-angle x-ray scatter (WAXS) have been investigated by various groups. The focus
of this dissertation was to develop a WAXS fat subtraction protocol for the WAXS
analysis of breast tissue biopsies. The WAXS signals of breast tissue could become
an additional source of diagnostic information.
Healthy breast tissue is composed of fat and broglandular ( brous) tissue. Com-
parisons of the WAXS signals of broglandular and cancerous tissue are di cult be-
cause biopsies of either type usually contain some fat tissue. The ability to look at
WAXS signals independent of the fat contribution could be informative. The goal
of this work was to validate a WAXS fat subtraction protocol using an animal tis-
sue sample consisting of a mixture of fat and brous tissue. The di erential linear
scattering coe cient d s=d
of a region of interest (ROI) within the sample was
measured via energy dispersive x-ray di raction measurements using a custom built
CdTe di ractometer. The mean fractional volume of fat ( fat) within the ROI was
estimated using a digital x ray imaging system. The transfer of the sample from the
iii
WAXS system to the digital system required accurate knowledge of the ROI. The use
of fat in a WAXS fat subtraction model then allowed the d s=d
of brous tissue to
be estimated. The signals obtained via the subtraction protocol agreed well with the
signals obtained using pure tissue samples.
The scattering coe cient d s=d
is a function of the momentum transfer argu-
ment x = 1= sin( =2), a variable that combines the dependence of scatter on photon
and scatter angle . Accessing a larger x space could provide more information
about the nature of breast tissue. Modi cations to the custom built di ractometer
were implemented in order to access a larger x space. Speci cally, the capability to
measure signals at smaller and the use of higher kV beams were the outcomes. Pre-
liminary results obtained with water, polymethyl methacrylate, and polycarbonate
samples were promising, yet suggested that better collimation is required between
the sample and the detector in order to reduce scatter contamination from objects
located downstream from the sample
Is it contagious? An eye-movement and EMG study of smile authenticity judgment
No full textA smile is commonly used to mask negative emotions, yet those emotions are often
leaked through microexpressions. These microexpressions act as brief displays of the
individual’s true emotion. Studies have indicated that participants often have difficulty judging
the emotional expressions as truly happy or not truly happy, even when the leaked emotion is
displayed for extended periods of time. The current study used a smile authenticity judgment
task and sought to understand why individuals have difficulty with these non-authentic smiles
(i.e. masking smiles; angry brow, angry mouth, disgust, fear, sad brow, and sad mouth). Various
judgment strategies were evaluated, such as explicit knowledge, attentional limitations (eyemovement
measures), emotional contagion (scale; ECS), and facial mimicry (electromyography;
EMG). Accuracy results were observed to be a function of emotional expressions, where
participants are more accurate with masking smiles containing fear and less accurate with
masking smiles containing anger in the brows. In addition, judgment strategies appear to be a
function of emotion. For instance, emotional contagion and facial mimicry were respectively
significant predictors of fear and angry mouth masking smile judgment accuracy. Alternatively,
attentional limitations were a significant predictor of angry brow masking smile judgment
accuracy. In sum, smile authenticity judgment of masking smiles and their respective strategies
appear to be as a function emotion
Promotion d’un poids santé parmi les hommes francophones du Grand Sudbury : une étude de cas de la participation au programme PairForm © et des effets à courtterme sur les connaissances et comportements de santé
No full textEn plus de souffrir davantage de surpoids, les hommes canadiens participent moins aux
interventions de gestion de poids que les femmes. La présente thèse poursuit un double
objectif : 1) déterminer les effets à court-terme de l’intervention éducationnelle
PairForm © sur l’acquisition des connaissances et changement de comportements en lien
avec l’activité physique, l’alimentation, la consommation d’alcool, le tabagisme et la
gestion du stress, et 2) examiner la perspective des participants à une intervention
d'éducation par les pairs. Une étude de cas avec une méthodologie mixte a permis une
évaluation approfondie du programme. Le taux de rétention de 100 % pour ce programme
pilote suggère qu’une intervention éducationnelle sensible aux hommes livrée par les
pairs favorise la participation des hommes en surpoids même si certaines absences
hebdomadaires étaient observées au cours de l’intervention. De plus, cette intervention a
permis aux participants de surmonter plusieurs obstacles envers une santé saine que pose la masculinité hégémonique. Mais, plus de recherches sont nécessaires afin d’encourager
les hommes à gérer leur poids
Design, construction and testing of a Tesla Turbine
No full textThis thesis presents the design, construction and testing of a boundary layer turbine, also known
as a Tesla Turbine. A turbine, with discs of 92mm in diameter, central exhaust, plenum
chamber, and swappable nozzles was constructed. The setup included instrumentation and a
simple torque sensor with which to sense the relatively low torques given the low testing
pressures. After construction, the setup was tested with various angles of nozzles ranging from
2.5° to 45° from tangential. The testing resulted in an estimated maximum efficiency of 8.5%,
while running the rig at 3 bar, which is comparable to the literature. Unexpectedly, this
maximum was achieved with a nozzle pointed at 45° from tangential, which may have been
caused by the disc pack variant used in the tests
Cyberbullying: interpersonal competence, aggression, and school identification.
Get PDFWith the development of and increased access to information and communication technologies a
new form of peer to peer aggression, cyberbullying, is on the rise. Research has only started to
skim the surface of this new form of bullying but, research has shown that there are numerous
negative outcomes associated with cyberbullying involvement whether it is as a cyberbully, a
cybervictim, both, or a witness. The current study investigated differences in aggression style,
interpersonal competence and school identification based on cyberbullying involvement as a
cyberbully, cybervictim, both or witness. As well the current study looked at how gender, age,
and grade related to cyberbullying involvement, and the impact of computer time, supervision,
and access to technology and location of home computers. One hundred twenty four students in
grades six through ten completed questionnaire packages, and there were significant differences
found in aggression style; cyberbully-victims had higher reactive aggression than cybervictims,
and interpersonal competence, specifically on asserting and conflict resolution subscales with
cyberbully-victims having lower competence scores than cybervictims. Significant results were
also found for access to technology. A correlational analysis was conducted to examine the
relationships between interpersonal competence, aggression, and school identification; numerous
significant results were found. As well an exploratory discriminant analysis was conducted to
determine if cyberbullying involvement could be predicted based on interpersonal competence,
aggression style, and school identification. Implications as they apply to research and
prevention are discussed
Correlates of rape myth acceptance, pornography use, and personality traits in undergraduate students
Get PDFThe purpose of this investigation was to examine the relationship between personality and pornography use in predicting rape myth acceptance. Rape myth acceptance was measured using The Illinois Rape Myth Acceptance Scale (1999); pornography use was measured the Pornography Use Measure (2014) as well as a direct question asking participants if they watch pornography (yes/no); personality was measured using Cattell’s 16PF, 5th Edition. A total of 67 participants (40 females, 27 males) were used in the analysis. Overall, rape myth acceptance was found higher in males than females overall, but was lower in males who knew a victim of sexual assault, particularly on the rape-myth subset “rape is a trivial event”. The global personality factors for Independence and Extraversion correlated negatively with rape myth acceptance in males; the global factor for Self Control correlated positively with rape myth acceptance for males. The global personality factor for Tough-Mindedness correlated positively in both males and females. No significant findings were found for pornography use
Polycyclopentene crystal-decorated carbon nanotubes by convenient large-scale in situ polymerization and their lotus leaf-like superhydrophobic films.
No full textIn situ Pd-catalyzed cyclopentene polymerization in the presence of multi-walled carbon nanotubes (MWCNTs) is demonstrated to effectively render, on a large scale, polycyclopentene-crystal-decorated MWCNTs. Controlling the catalyst loading and/or time in the polymerization offers a convenient tuning of the polymer content and the morphology of the decorated MWCNTs. Appealingly, films made of the decorated carbon nanotubes through simple vacuum filtration show the characteristic lotus-leaf-like superhydrophobicity with high water contact angle (>150°), low contact angle hysteresis (<10°), and low water adhesion, while being electrically conductive. This is the first demonstration of the direct fabrication of lotus-leaf-like superhydrophobic films with solution-grown polymer-crystal-decorated carbon nanotube
Bioelectrical and biophysical interactions across spatio-temporal domains: identifying the conduit for the emergence of material from the immaterial
No full textThe emergence of biophysical and bioelectrical dynamics at the level of the organism are explored in an attempt to identify the physiological correlates of the onset of senescence in plants. Furthermore, the ability of phylogenically disparate entities to demonstrate the potential to simultaneously display correlated electro-dynamic processes akin to sharing the "same space" or spatial parameters is investigated. The underlying, aforementioned electrophysiological changes associated with senescence and the potential for phylogenically disparate systems to display markedly correlated processes may share water as a common source of variance. The imperative investigations on the physical nature of water and its interactions with applied electromagnetic fields with respect to enhanced latency of the onset of deviations in pH and enhanced electro-dynamic correlations are experimentally explored. A hypothesis, supplemented by marked quantitative convergence, suggests that water is the central conduit necessary for the emergence of material from the immaterial
Endocrinological manipulations and initial maternal behaviour in the Virgin rat (Rattus norvegicus)
No full textSteroidal hormones are known to mediate maternal behaviour by influencing specific neural
structures that are responsible for initial onset and maintenance of this behaviour. Contrary to
typical extirpation and replacement strategies, this study examined hormonally intact animals to
evaluate the specific effects of hormonal enhancement in conjunction with endogenous
fluctuations on maternal behaviour. Rats were given a regimen of estrogen and progesterone
hormones via osmotic pumps and subcutaneous injections to mimic natural pregnancies.
Maternal behaviours were recorded for a twenty-four hour observation period either immediately
after parturition or after a sensitization period to foster pups. Neural tissue was removed from
the medial preoptic area after the observation period and prepared for future analysis with
electron microscopy. Behavioural results from this study revealed that initial behaviours are not
influenced in exogenously enhanced virgins compared to virgin and pregnant controls. These
results suggest the significance of neural moderation on the onset and magnitude of maternal
behaviour
Youths aging out of foster care and their experiences learning mindfulness in an arts-based group program.
Get PDFAs the field of research investigating mindfulness-based interventions (MBIs) continues to expand, studies implementing MBIs with older marginalized youth are scarce. I developed and explored the implementation of an innovative MBI with a small group of youth transitioning out of foster care due to their age. In general, these youth remain underrepresented in qualitative research processes, furthering their public “invisibility” and hampering our understanding of their long-term health and education outcomes. Since we know that many youth in care suffer a variety of long term negative consequences due to experiences of trauma, loss, and family dysfunction, and because we lack understanding regarding beneficial programs for these youth, research is necessary to support policies and programs that promote the resilience of youth in care. I was interested in better understanding these youths’ viewpoints about resilience, and their understanding of mindfulness. The lack of research exploring MBIs with youth aging out of foster care necessitated an exploratory approach. Applying qualitative inquiry and a constructivist lens, I collected data from eight participants who participated in two different groups. I interviewed the youths using open-ended questions in three semi-structured interviews prior to, immediately after, and four months following participation in a holistic 10-week arts-based mindfulness group program. A follow-up meeting was held with all of the youth one year after the groups were completed. Using an inductive form of interpretive thematic analysis, my analysis of the data yielded themes illustrating the participants’ perceptions of the challenges that they endured; the key features of resilience; their understanding of mindfulness; the benefits of learning mindfulness; and the perceived helpfulness of the group experience. These findings helped me to illustrate new insights about the benefits, challenges, and opportunities afforded by implementing MBIs with older youth in care. I found that the arts-based mindfulness group program was suitable and the youth expressed several benefits of learning mindfulness for their day-to-day lives including increased self-awareness and improved emotion regulation. The implications for service providers and other allies of marginalized youth are considered, and recommendations for future researchers are provided