4 resultados para rupture

em Brock University, Canada


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Boron trihalide and mixed boron trihalide adducts of trimethylamine have been prepared, and characterized by proton and fluorine N.M.R. spectroscopy. The acceptor power of the boron trihalides was seen to increase in the order BF3 < BC13 < BBr3 < BI3, corroborating previous evidence. The mixed boron trihalides had intermediate Lewis acidities. Solution reactions between adducts and free boron trihalides rapidly led to the formation of mixed adducts when the free boron trihalide is a stronger Lewis acid than that in the adduct. A slower reaction is observed when the free BX3 is a weaker Lewis aoid than that complexed. The mechanism of halogen exchange leading to the mixed (CH3)3NBX3 adducts was investigated. 10B labelling experiments precluded B-N bond rupture as a possible mechanism in solution; results are discussed in terms of halogen-bridged intermediates. Pre-ionization may be important for some systems. At higher temperatures, during gas phase reactions,B-N coordinate bond rupture may be the initial step of reaction. Two mixed adduots, namely (CH3)3NBClBr2 and (CH3)3NBHOIBr were prepared and characterized by Mass Spectrometry

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This thesis applies x-ray diffraction to measure he membrane structure of lipopolysaccharides and to develop a better model of a LPS bacterial melilbrane that can be used for biophysical research on antibiotics that attack cell membranes. \iVe ha'e Inodified the Physics department x-ray machine for use 3.'3 a thin film diffractometer, and have lesigned a new temperature and relative humidity controlled sample cell.\Ve tested the sample eel: by measuring the one-dimensional electron density profiles of bilayers of pope with 0%, 1%, 1G :VcJ, and 100% by weight lipo-polysaccharide from Pse'udo'lTwna aeTuginosa. Background VVe now know that traditional p,ntibiotics ,I,re losing their effectiveness against ever-evolving bacteria. This is because traditional antibiotic: work against specific targets within the bacterial cell, and with genetic mutations over time, themtibiotic no longer works. One possible solution are antimicrobial peptides. These are short proteins that are part of the immune systems of many animals, and some of them attack bacteria directly at the membrane of the cell, causing the bacterium to rupture and die. Since the membranes of most bacteria share common structural features, and these featuret, are unlikely to evolve very much, these peptides should effectively kill many types of bacteria wi Lhout much evolved resistance. But why do these peptides kill bacterial cel: '3 , but not the cells of the host animal? For gramnegative bacteria, the most likely reason is that t Ileir outer membrane is made of lipopolysaccharides (LPS), which is very different from an animal :;ell membrane. Up to now, what we knovv about how these peptides work was likely done with r !10spholipid models of animal cell membranes, and not with the more complex lipopolysa,echaricies, If we want to make better pepticies, ones that we can use to fight all types of infection, we need a more accurate molecular picture of how they \vork. This will hopefully be one step forward to the ( esign of better treatments for bacterial infections.

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Entering Youth work Through Love's Many Pathways is a text that wanders and digresses to places where, through poetic inquiry and a Spinozist and Sufi framework, the concepts of immanence, love and becoming can be explored. This thesis is framed as a walk through which the researcher / youth worker along with the reader, traverses through five pathways that she considers necessary in cultivating a meaningful relationship with the youth: opening, strength, listening, trust and unconditional compassion. By means of engaging the “self”, this thesis approaches youth work as a field that is relational and socially interconnected. In this sense, this poetic inquiry seeks to rupture predictable patterns of behaviour. One of the ways I do this is through found poetry. Through this specific form of poetic inquiry, I bring together various voices, an assemblage – Rumi, Rilke, Whitman, Lalla, Mirabai and Song of Songs – in order to find my voice and by extension, to help the youth find their voice through a human connection that goes beyond colour, race, gender etc. In other words, my aim is to actualize the experiences of becoming youth worker while being in a field of immanence where similarities are understood and differences respected. My hope is that this project may offer an example of understanding, celebration, and engagement of our mutual differences, while still being able to relate to one another through the many pathways of love.

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This thesis is written through the front-line perspective of a child/youth worker who has experienced ‘rupture’ in her personal understanding of the Child Youth Care (CYC) practice. Using a collection of personal journal entries written about her individual experiences of CYC education, mentorship/training, front-line residential practice and frequently used interventions, this thesis takes the reader (and the writer) on a discovery of prominent discourses that exist within the residential CYC profession. Focusing on the use of physical restraints on children by residential Child/Youth Workers, this research project utilizes Deconstructive Discourse Analysis and Liberation Psychologies to illustrate a critical examination of power-knowledge and scientific/medical discourses in CYC practice. By focusing on Foucault’s concepts of disciplinary power, binary division and theory of panopticism, the writer seeks to explore a personal reflection and comprehension of how power is used to assert control over children/youth through mental health treatment and physical interventions.