title: Selective knowledge transfer from K-nearest neighbour tasks

contributor:
Su, Yuan (author)
(Silver, Daniel L.) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: The thesis explores how a learning system can utilize previously learned  knowledge to develop a more accurate hypothesis in the context of the k nearest  neighbour (kNN) learning algorithm. Several previous methods of knowledge transfer for  kNN have proposed measures based on structural similarity at the task level. A theory of  selective knowledge transfer is presented using a measure of relatedness based on  functional similarity at the classification level.  The new method of knowledge transfer relies on the generation of virtual  instances for the primary task from training instances of the secondary task. Each virtual  instance is non-deterministic in that the probability of its class value is conditioned upon  the class value of the secondary task. Virtual-instance-based Non-Deterministic kNN  (VND-kNN) is introduced as an implementation of the theory.  A prototype system based on the theory is tested against a synthetic domain and a  letter recognition domain. Experiments show that knowledge transfer from secondary  tasks based on the conditional probability distributions can improve the generalization  accuracy of the primary task if the secondary tasks are related to the primary  task. Furthermore, experiments show that the method is able to mitigate negative transfer  of knowledge when the secondary tasks are unrelated to the primary task.

abstract: Computer Science


title: Sex in the dark: A review of the literature and ideas concerning concealed ovulation in the human female

type: Text Dissertation/Thesis

contributor:
Clarke, Ashley Anne Elizabeth (author)
(Snyder, Marlene) (Thesis advisor)
Acadia University (Degree grantor)

rights: The author grants permission to the University Librarian at Acadia University to reproduce, loan or distribute copies of my thesis in microform, paper or electronic formats on a non-profit basis. The author retains the copyright of the thesis.

subject: LE3 .A278 2006

abstract: Most mammalian females engage in sexual activity during distinct periods of receptivity  termed estrus, which coincides with the period of fertility. Sexual activity in human  females, however, is characterized by the absence of specific times of receptivity or  proceptivity, and by the lack of advertised fertility (via either behavioural or physical  cues), which is dubbed “concealed ovulation”. Although strikingly rare, concealed  ovulation is not confined to human females, yet there has been little investigation of its  occurrence in other organisms. An examination of the literature has revealed several  prominent theories hypothesizing the adaptive value of this phenomenon in humans: a  strategy to obtain parental care, prevention of infanticide by reducing male-male  competition, female avoidance of copulation during estrus to evade pain and death  associated with child-birth, increasing cuckoldry of males after established monogamy,  female acquisition of meat from successful male hunters, psychological self-deception,  preference for prolonged paternal investment over mate quality, increased paternal care,  and the result of structural and functional changes related to bipedalism. Interest in  concealed ovulation has generated a wealth of research about such diverse topics as  primate mating systems, human pheromones, women’s perceptions of their time of  fertility, menstrual synchrony, and coital frequencies. To date, consensus regarding the  evolutionary origins of concealed ovulation as well as its role in human sexual adaptation  continues to be contested. Avenues for future research include obtaining more extensive  data on primate reproductive cycles and behaviour, providing a more complete  phylogenetic understanding of concealed ovulation, and a meta-analysis of literature  ix  suggesting possible cues indicating maximum fertility in humans, which would facilitate  examination of the validity of the research available.

abstract: Biology


title: Wage discrimination in the National Hockey League

contributor:
Lebo, Alastair J. (author)
(VanBlarcom, Brian) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: This study examines wage determination and discrimination in the National  Hockey League (NHL) during the 2002-2003 and 2003-2004 seasons. The existence of  discrimination in the NHL is based on a bilateral monopoly framework with differences  in bargaining power between North American and European players.  Using ordinary least squares regressions, player skill data and nationality are used  to explain salary levels. The initial results were designed to determine if wage  differentials exist between Canadian, American and European players regardless of their  playing location.  Additional player attributes and playing location variables were added to further  investigate possible wage discrimination. After correcting for differences in skill sets, it  was found that European forwards are paid more on average than Canadian forwards.  When adding United States versus Canadian franchise location variables, the analysis  indicated that European forwards playing in Canada or the United States earn more than  Canadian forwards playing in Canada. It was also found that European defensemen  playing in the United States earn more than Canadian defensemen playing in Canada.  This study detected no wage differential between European and Canadian defensemen  playing in Canada.

abstract: Economics


title: The fate of Escherichia coli in Bay of Fundy sediment

contributor:
MacDougall, Kristin J. (author)
(Bell, Colin) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: The study of the survival of Escherichia coli in marine water and sediment is  important as E.coli is commonly used as an indicator of fecal contamination which can  pose a major public health threat. If E.coli is able to persist or even grow in an aquatic  system then it would not be an accurate measure of fecal pollution. In this study a  microcosm system was used to investigate the survival of E.coli in marine sediment and  water over a two week period. The effects of several different variables on E.coli survival  in this system were tested over 11 trials. These variables included using four different  strains of E.coli, three different salinity levels, and two different water cycling designs. A  general successional pattern of E.coli in the microcosm system was determined to consist  of E.coli disappearing from the water at high tide much faster than it did from the  sediment. By comparing the four different strains of E.coli it was determined that the  aquatic E.coli fared better in the marine environment than the animal isolate. When  observing the effects of salinity on E.coli it was determined that E.coli fared better at a  salinity of 5ppt. Deep sediment samples were taken which confirmed that E.coli was able  to penetrate the sediment at a depth of at least 6cm. Two water cycling patterns were  compared to find that the observed amount of E.coli only rose above the predicted E.coli  level in trial 2 which used marine E.coli. It was determined that E.coli levels rose above  the predicted level throughout the trials where the systems water was drained and  replaced on a 12h tidal cycle. This result indicated that E.coli is able to persist and  possibly grow in a marine microcosm system suggesting that it may not be an accurate  measure of fecal pollution in a marine environment.

abstract: Biology


title: Leave no trace knowledge and adherence to minimal impact practices: A case study of current and potential users of the Cape Split trail

contributor:
Rive, Kate (author)
(Bissix, Glyn) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: This study analyzes the effectiveness of education as a form of indirect  management to address the ecological degradation that results from human presence in  the wilderness. As human use of the wilderness continues to escalate, the need for an  effective management approach to decrease impact becomes increasingly apparent. The  use of an educational approach to accommodate this need is appealing, as research  indicates that most actions that damage the wilderness result from a limited amount of  minimal impact knowledge. The organization Leave No Trace is at the forefront of  promoting and distributing minimal impact education materials to wilderness users in  North America, as a means of encouraging more knowledgeable and environmentally  sensitive recreation behavior.  This study identifies respondentsâ€™ present level of Leave No Trace Knowledge,  their ethic for the environment and their corresponding self-reported behavior when  recreating in the outdoors. A sample of both current and potential users of the Cape Split  Trail served to identify the various minimal impact knowledge levels of selected user,  community and educational groups. The results indicated a difference in how these  groups responded to various questions on Leave No Trace knowledge, however, many  similar response patterns indicated the need for additional emphasis on certain Leave No  Trace principles. The conclusions and recommendations derived from this study serve to  direct future educational efforts to better protect environmentally fragile areas such as  Cape Split.

abstract: Kinesiology


title: Forging a head: A tail of new frontiers

contributor:
Topping, Kaila A. (author)
(Gibson, Glenys) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: The marine polychaete Pygospio elegans has the capability to regenerate a new  head in just 8 days with amazing consistency and faithfulness to the original body plan.  Previous studies, based on histological observations describing morphogenesis at various  stages of anterior regeneration, have suggested that mesodermally derived structures have  an interesting mode of regeneration. The present study attempted to study the cell origin,  migration and fate of the regenerating tissue, with emphasis on mesodermally derived  cells. I microinjected specimens with the fluorescent vital dye DiI to track cells during  formation of the blastema (i.e., regenerating tissue), then induced fission between the  abdomen and the thorax. Specimens at 3 and 6 days of regeneration were observed using  confocal laser scanning microscopy. I also observed cell proliferation using BrdU, which  labels actively dividing cells. Only specimens injected into the first abdominal segment  showed any fluorescence in the blastema, suggesting that only the adjacent segment  contributed cells to the regenerating regions. However, not all regions of the adjacent  segment contributed to the blastema. The fluorescence within the blastema was always  localized to certain areas or organs within the blastema. Within mesodermal structures,  there appear to be different modes of regeneration. For example, the blood vessels appear  to regenerate by growing into the blastema from the original blood vessels, whereas the  muscles seem to differentiate from the small mesenchyme-like cells which fill the  blastema before organogenesis begins. BrdU labeling was not successful in penetrating  into the mesoderm, but revealed a lot of epidermal cell proliferation, which was not  previously thought to occur. These results suggest that mesodermal tissues regenerate  from different source populations.

abstract: Biology


title: AIDS activism in Sub-Saharan Africa: A hybrid approach

contributor:
MacLean, Lauren Alin Kathryn (author)
(Grieve, Malcolm) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: The African continent is facing its worst health crisis yet â€“ HIV/AIDS. So much work is being done to minimize its impact that it is difficult to determine what is effective. This thesis examines the various contributors to AIDS activism in Sub-Saharan Africa to develop a model for effective and appropriate AIDS activism. By examining theoretical concepts of activism and development, a foundation of power analysis within the context of the bottom-up framework for development is established. An understanding of resources and interactions between levels of AIDS activism forms the  basis of the argument in support of grassroots initiatives. Through case study analysis of AIDS activist initiatives and a regional comparison, the proposal for a hybrid AIDS activist system is put forth. Leveraging the strengths of grassroots activism, intermediary organizations and international institutions, the hybrid AIDS activist system becomes the  global strategy to address the HIV/AIDS pandemic. A product of the integration of the various levels of AIDS activism is the organization which, within itself, utilizes multiple approaches of AIDS activism. Equally important in the hybrid system is the  acknowledgment of the work of the individual activist, who has successfully utilized their skills and experience to benefit the AIDS activist cause. In the end, only the collaboration  of all levels of AIDS activism will produce a global effort which successfully addresses AIDS in Africa.

abstract: Politics


title: Transplantation of porous tubes following spinal cord transection improves hindlimb function in the rat.

contributor:
Reynolds, Luke F. (author)
(Murphy, René) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: Spinal cord injuries are very serious medical problems that require acute and  chronic treatment. The primary effects of a spinal cord injury are the loss of motor and  sensory function. The varying degrees of spinal cord injury are due to the amount of  cellular damage and the level of the injury. The amount of spared tissue, scar tissue, and  neuronal growth all affect the recovery process and secondary effects.  Skeletal muscle experiences a number of effects following a spinal cord injury  such as atrophy, and changes in metabolic properties. The different changes in the  skeletal muscles have profound effects on the recovery and quality of life of spinal cord  injured individuals. Briefly, the muscle fibres experience a shift to a faster more fatigable  fibre type. The muscle enzymatic characteristics become less oxidative and more  glycolytic due to the alterations in mitochondrial number and function. The effects of the  spinal cord injury on skeletal muscle are probably due to a decrease in mechanical load  and neuromuscular activity.  Several interventions are being studied to reverse the effects of spinal cord injury  on skeletal muscle. In the present study, a porous tube transplant was placed in the spinal  cord at the site of injury for 28 days following a complete spinal cord transection in a rat  model of spinal cord injury. Daily measurements of body weight were performed.  Locomotor function was assessed weekly. Following 4 weeks of intervention, relative  muscle weight and oxidative enzyme activity was studied in hindlimb skeletal muscles.  The relevant findings of this study are that porous tubes can increase locomotor  function, and decrease the amount of cellular damage following a complete spinal cord  transection. Also, cytochrome C oxidase activity in the plantaris can be maintained with the use of a porous tube following a spinal cord transection. The application of porous  tubes in the spinal cord injury population would be using it as a rehabilitation tool; for  increasing locomotor function, and decreasing the negative effects experienced by the  affected muscles.

abstract: Kinesiology


title: A biomechanical analysis of caregivers diverse folding and unfolding techniques using lightweight wheelchairs: an ergonomic evaluation

contributor:
Lebert, Danielle (author)
(Seaman, Roxanne) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2005

abstract: The purpose of this investigation was to gather both qualitative and quantitative data regarding the methods currently used by caregivers to fold and unfold a lightweight  manual wheelchair for children. Seven caregivers were recruited from Acadia  University's Sensory Motor Instructional Leadership Experience (SMILE) program to  participate in this study. Participants were asked to demonstrate their usual folding and  unfolding methods using a standard lightweight manual wheelchair, cross-brace design. As outcome measures, a questionnaire, a visual analogue scales of perceived exertion and back strain, and Ovako Working Posture Analysis System (OWAS) back scores were used.  The study found that the methods used by caregivers while folding / unfolding a wheelchair were associated with awkward, non-neutral trunk postures in extreme positions or at extreme angles. As such, all participants were scored with an OWAS score of 2 of higher. These results underscore the need to ensure that proper methods are used to reduce the likelihood for low back injuries and/or strain. The fact that primary caregivers used improper biomechanics to fold / unfold a manual wheelchair up to two-three times a day warrants concern. The results of this study suggest the need for formal education on recommended methods appropriate for the caregiver's personal biomechanics and anthropometries.

abstract: Kinesiology


title: Enzyme-assisted kinetic resolution of novel 2-naphthol mannich bases

contributor:
MacLean, Erin Dickson (author)
(Jha, Amitabh) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2007

abstract: Estradiol (the most active estrogen) is a steroid hormone found in the body. It plays a role  in bone maturation, the regulation of the lipid profile in blood, the development of sexual  characteristics, and the growth of breast cancer cells. Selective estrogen receptor  modulators (SERMs) are synthetic molecules designed to stimulate or inhibit the effects  of estrogen. Tamoxifen and raloxifene are currently available SERMs used for the  treatment of breast cancer and osteoporosis respectively. The structure of potential  designed SERMs mimics the estrogen backbone and placement of hydroxyl groups.  Induction of a chiral center serves to increase the specificity of the molecule, and the  addition of an amino side-chain effectively emulates the structure of clinically used  SERMs.  The purpose of this research is to design a method for the synthesis of novel potential  SERMs. To achieve this, enantioselective synthesis of structurally simpler analogs of  designed potential SERMs was investigated. The Mannich reaction was used to  synthesize 2-naphthol Mannich bases using 2-naphthol, 4-piperidinol, and 10 different  aromatic aldehydes. These 10 chiral Mannich bases were then resolved using an enzyme-assisted  chemo, regio, and enantioselective acetylation process in an organic solvent. The  optical enrichment was achieved as evidenced by measurement of the optical rotation of  the mono-acetylated product and unreacted dihydroxy compound.

abstract: Chemistry


title: Queer consequences: Homosexuality and its penalties in the Canadian military, 1939-1945

contributor:
Osborne, Zachary J. (author)
(Henderson, Stephen) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2007

abstract: In the early years of the Second World War, the Canadian military began to  enforce discriminatory anti-homosexual policies that had harmful short and long-term  effects on the lives of gay personnel. This thesis will address this problem as well as the  secondary issue that the military rooted out competent personnel not because they were  unqualified for combat or hindered military efficiency, but because of homophobia and  the moral self-righteousness of policing investigators, senior officers, and medical  professionals.  From de-classified military documents in RG 24 of the Library and Archives of  Canada, case studies of homosexual servicemen and their court martial proceedings will  be presented to reveal the harsh legal actions taken against gay recruits. These will  demonstrate discriminatory and unfair sentencing against men who were discovered as  homosexual.  Men who were found guilty of homosexuality were sentenced to various  punishments, ranging in severity from detention and hard labour periods to a  dishonourable military discharge, but all having powerful psychological, emotional, and  financial consequences able to push some men to commit suicide. Ultimately, this thesis  attempts to contribute to new military history, gender studies, and the growing focus on  gays and lesbians in mainstream histories.

abstract: History & Classics


title: The role of relaxin in the reduction of cellular injury in response to ischemia: A study using two rat brain slice preparations

contributor:
Rappaport, Rebecca (author)
(Wilson, Brian) (Thesis advisor)
(Smith, Todd) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2007

abstract: Relaxin is a hormone with widespread and varied effects in animals. For  example, relaxin has been shown to reduce the cellular damage associated with  ischemia and reperfusion in the heart, intestine, pancreas, and brain. This study  was performed to investigate the effects of relaxin on damage to the brain  sustained during ischemia and reperfusion. Two studies were performed: an acute  study using freshly harvested slices of adult rat brain and a study using  organotypic cultures of newborn rat brain. Damage, the amount of dead tissue,  was assessed in the acute system using triphenyltetrazolium chloride staining, and  assessed in the organotypic system using propidium iodide staining. Paraffinembedded  organotypic slices were also immunostained for heat shock proteins 27  (Hsp27) and 70 (Hsp70) to determine if relaxin had a direct effect on cellular  stress responses in glial cells and neurons. In both the acute and organotypic  models, relaxin treatment slowed the progression of ischemic damage. Hsp70  immunostaining was initially reduced immediately following ischemia with  respect to the slices not exposed to relaxin, whereas Hsp27 immunostaining was  minimal. Hsp70 immunostaining increased at the 3 hour post-ischemia time point  and Hsp27 immunostaining decreased. These results suggest a cellular role for  relaxin in reducing the cellular stress associated with ischemia.

abstract: Biology


title: The politics of motherhood: The construction of maternal identity in Arundhati Roy's  The god of small things

contributor:
Chamberlin, Heather D. (author)
(Eustace, John) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2007

abstract: Using Judith Butler and Seyla Benhabib's theories on social constructivism and  identity constitution, this thesis argues that Arundhati Roy’s novel The God of Small  Things provides literary evidence for the possibility of individual agency and, indeed,  self-determination in a socially constructed world. Specifically, it argues that the use of  individual narrative, as a means of identity constitution, provides the opportunity for  agency in the socially constructed role of motherhood. Each chapter discusses the  experiences of individual female characters as a means of negotiating the relationship  between the socially constructed role of motherhood and the individual experiences of  mothering. This thesis concludes that one can find agency in the process of actively  negotiating one's individual narrative.

abstract: English & Theatre Studies


title: A naked beginning: Lack of larval structures in benthic young of the poecilogonous polychaete Streblospio benedicti Webster

contributor:
Coxhead, Megan (author)
(Gibson, Glenys) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: Streblospio benedicti is a spionid polychaete that exhibits poecilogonous development. Two morphs of young are produced: some females produce planktonic, feeding larvae (i.e., planktotrophy) while others produce non-feeding, benthic young (i.e., lecithotrophy). My objectives are to analyze lecithotrophic larval development by using bright field and scanning electron microscopy, and to compare this data to literature descriptions of planktotrophic young. General trends that were observed in lecithotrophic young were an overall accelerated development of the adult form through rapid segmentation, the lack of expression of some larval traits (including the absence of swimming chaetae), delayed differentiation of structures that are non-functional in lecithotrophic morphs (for example, a delay in gut tube formation), and variation within key life-history traits all relative to the planktotrophic morph. Variation in life history traits occur both within and between developmental morphs, and include age and developmental stage at release from the brood sac, and growth rates (as segmentation) within the brood sac. This suggests these traits may be additionally available for natural selection within a developmental morph.

abstract: Biology


title: A thermodynamic investigation of the kinetics of the reaction of bromine atoms with ethers

contributor:
Wheeler, Michael J (author)
(Roscoe, John M.) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: A reaction chamber for studying atmospheric photochemistry was used to obtain the rate constants for the reaction of diethyl ether with atomic bromine as a function of temperature. Analysis was performed with gas  chromatography and rate constants were calculated from these results using the relative rate method. 2,2,4- Trimethylpentane was used as the reference reactant.  The Arrhenius parameters were evaluated from the temperature dependence of the rate constant for this reaction. It was found that the reaction of diethyl ether with atomic bromine had a pre-exponential factor of 1.96 (Â± 0.21) Ã— 10-10 cm3 molecule-1 s-1 and an activation energy of 19.8 (Â± 2.6) kJ mol-1. The reaction mechanism was determined to be hydrogen abstraction. A thermodynamic analysis of the Arrhenius parameters was performed and comparisons were made between reactions of ethers with atomic bromine  and atomic oxygen. A mechanistic approach was used to explain the differences in reactivity between diethyl ether and dimethyl ether. It was found that the enthalpy of activation for the reactions of diethyl ether and dimethyl ether with atomic bromine agreed within experimental error; however, the entropy of activation of the reaction with diethyl ether was 40 J K-1 mol-1 larger than that for the reaction with dimethyl ether. Comparison of the corresponding reactions of atomic oxygen also showed that there is a larger value of the entropy of activation for the  reaction with diethyl ether than for the reaction with dimethyl ether. This difference was interpreted to indicate a looser transition state for the diethyl ether reactions than for  those of dimethyl ether. The more substantial difference in entropy of activation of the six bromine reactions was attributed to the decreased ability of bromine atoms to polarize the C-H bond as compared to atomic oxygen. This decreased polarization of the C-H bond led to a looser transition state and, in turn, a larger value of the entropy of activation. A comparison was made between the rate constant for the reaction of diethyl ether with atomic bromine and that for the bromine atom catalysed destruction of ozone. It was found that in order for the two reactions to compete, the atmospheric concentration of diethyl ether would have to be approximately 18 times larger than the concentration of ozone.

abstract: Chemistry


title: The expression and evolution of relaxin in Danio rerio

contributor:
Glen, Peter N.C. (author)
(Wilson, Brian) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: In recent years, relaxin research in mammalian systems has shown that  there are multiple functional forms of relaxin with distinct physiological roles.  However, evidence of relaxin’s presence in teleost fish has been limited to  comparative genomics. These studies have shown that there are multiple  relaxin-like gene sequences in teleosts with uncharacterized expression and  function. To explore the expression of relaxin in teleosts, zebrafish (Danio rerio)  were used as a model species because of the recent publication of its assembled  genome. Searching of the NCBI and Ensembl databases yielded five relaxin-like  sequences in the zebrafish genome. These were used to develop novel, nondegenerate  primers for use in PCR. Zebrafish were raised at Acadia University  to maturity and DNA was extracted for gene amplification through PCR.  Attempts to isolate relaxin from genomic DNA were unsuccessful. RNA was then  extracted from tissue specific regions (brain, liver/intestine, ovary), and used to  generate cDNA. These analyses generated PCR products of the expected 300  bp size for three of the five relaxin sequences, however sequencing showed that  product was zebrafish rRNA. The five relaxin sequences identified in the  zebrafish genome were compared to the sequences in humans, mice, and  Takifugu rubripes using a Minimum Evolution tree, which showed that there are  multiple forms of relaxin in zebrafish. This suggests that the broad teleost  “Relaxin-3” nomenclature needs to be subdivided. Though expression of relaxin  in zebrafish was not definitively shown, bioinformatic evidence suggests it is  present in multiple forms.

abstract: Biology


title: Proactive regulation: The registration of hedge fund advisers

contributor:
Frazier Jr., Paul (author)
(VanBlarcom, Brian) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: The mandatory registration of certain hedge fund advisers by the United States Securities  and Exchange Commission was established to improve investor protection within the  financial services sector. This new rule was met with objection from both industry  professionals and trade associations. Critics on supporting and opposing sides put forth  valid concerns related to its implementation. With significant emphasis on secondary  research, this thesis conducts a closer study of regulatory intentions, administrative  implementations, and industry ramifications in determining whether registration of hedge  fund advisers is an appropriate step for the industry. A study of this issue involves a  review of the fundamentals of investor protection and an analysis of the costs, benefits,  and alternatives of registration. The study suggests that the mandatory registration of  hedge fund advisers is an appropriate action for strengthening investor protection.

abstract: Business


title: In pursuit of novel antibacterial fluoroquinolones

contributor:
Heath, Raie Lene (author)
(Jha, Amitabh) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: Fluoroquinolones are a class of synthetic antibacterial agents used to fight against  the ever growing and evolving amount of bacterial infections currently affecting  people worldwide. Among other substituents, these compounds bear a  carboxylate group at position 3 and an N-heterocyclic ring at position 7 of the  quinolone ring. As part of a larger research initiative in our lab, fluoroquinolones  were designed where a phosphonate group replaced a carboxylate group and new  heterocyclic rings (4-aminopiperazinyl and 4-amino-3,5-dimethylpiperidinyl)  were introduced. For the present investigation, efforts were made to synthesize  these heterocyclic rings. 4-Tert-butoxycarbonylamino-1-benzylpiperazine and 4-  nitro-3,5-dimethylpyridine were synthesized as precursors to 4-tertbutoxycarbonylaminopiperazine  and 4-amino-3,5-dimethylpiperidine  respectively. The final reaction steps could not be completed owing to time  constraints. After successful synthesis of these heterocyclic ring systems,  synthesis of fluoroquinolone-3-phosphonates will be undertaken. Eventually the  two will be attached to yield the target compounds. It is hoped that the final  products will not only show enhanced potency to known fluoroquinolones, but  will also be effective against resistant strains of bacteria.

abstract: Chemistry


title: Implementing formal languages in Maple

contributor:
McCarlie, Ryan M. (author)
(Domarat, Michael) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: The implementation of formal languages in Maple has proved itself worthwhile, increasing  our knowledge of the subjects at hand and helping users gain intuition about  regular languages using hands-on experience. Regular expression validation is a very  important subject in the area of formal language theory. Research in this area is minimal  and few textbooks define how regular expressions are allowed to be structured .  In Maple, we implement the definition from Lee and Shallit [14] to create a regular  expression validator that can be used by researchers in this field. We also develop a  Maple procedure for transforming a regular expression into a finite automaton, using  an algorithm from Aho et al. [2]. Lastly, we extend the finite automaton manipulation  package aut.m developed by Martoi [17] to implement the operations of shuffle and  shuffle on trajectories.

abstract: Computer Science


title: Field emission from vertically aligned carbon nanotubes

contributor: (Mohajerzadeh, Shamsodin) (Thesis advisor)

subject: LE3 .A278 2006

abstract: Carbon nanotubes (CNTs) have a diverse range of applications as a result of their  high surface area, high strength, and very unique electronic properties and this thesis  studied the electrical characteristics of a triode electron emission device. In particular, the  mechanism by which electrons are emitted from the tip of the CNT was investigated. A  finite element analysis package, FlexPDE3 Â©, was used for electrostatic modeling of the  particular triode geometry. From these simulations, it was determined that the magnitude  of the electric field at the nanotube tip had a linear dependence on the voltage applied to  the anode and gate electrodes. These results, coupled with Fowler-Nordheim theory,  predicted theoretical results that corresponded very well with experimental results  obtained by Mohajerazedah et al.1 Saturation in the emission current was also observed  and possible explanations were noted. The diffraction of the electron beam was modeled  using Fresnal diffraction theory and some numerical results applying to the particular  triode geometry were obtained. Finally, a plausible mechanism for controlling beam  diffraction was considered.

abstract: Physics


title: Development and application of electrochemical methods to study adsorption of imidazole on gold (111)

contributor:
Birnie-Lefcovitch, Simon (author)
(Zamlynny, Vlad) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: A procedure for the generation of a gold (111) single crystal electrode to be used  in polarization modulation infrared reflection absorption spectroscopy (PM IR RAS) and  electrochemical impedance spectroscopy (EIS) studies of thin organic films deposited on  metals was developed. This method involved the production of the initial single crystal  by induction furnace, and the final orientation of the (111) crystallographic plane using  X-ray diffraction (XRD) Laue back scattering photography. The desired surface was then  polished using sandpaper, diamond lapping film, and finally a polycrystalline 1 Î¼m  diamond suspension followed by 0.05 Î¼m colloidal alumina.  The orientation of this single crystal was confirmed by cyclic volatammetric (CV)  measurements. The single crystal electrode was then used to validate an EIS setup. This  was done by performing EIS measurements on both the bare gold electrode and the  electrode covered with imidazole film adsorbed onto the surface and comparing the  results to CV results published in the literature.  These tests have concluded that a gold (111) single crystal electrode was  successfully produced, oriented and polished. The tests conducted on the EIS setup  indicate that the equipment is working reliably, providing results similar to those reported  in the literature.

abstract: Chemistry


title: Synthesis and characterization of gold nanoparticles

contributor:
Murphy, Stefan Matthew (author)
(Williams, Peter) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: Using the process of laser ablation, spherical gold nanoparticles suspended in a liquid,  whose size can be varied between 2 and 10 nanometers in diameter, and whose dispersion  can be limited, were synthesized and characterized for use in single molecule  conductivity measurements.  Particle size control was demonstrated using varying laser fluence and solutions  of -cyclodextrin. The control methods worked as expected but failed to exlude  populations of large particles, prompting the trial of centrifigation as a method of  removing these particles. The centrifuging process was effective in one instance, but  could not be repeated in a subsequent trial.  Transmission electron microscopy (TEM) was an effective, but time consuming  method of particle characterization. Dynamic light scattering (DLS) was attempted  as an alternate characterization method. DLS analysis producing number-weighted  size distributions matches TEM data the closest, however this analysis is not possible  for the highly polydisperse samples produced. Only intensity-weighted distributions  can be produced, from which no conclusions about DLS correlation to TEM were  drawn.

abstract: Physics


title: Development and application of spectroscopic techniques for the characterization of barrier films

contributor:
Read, Stuart T. (author)
(Zamlynny, Vlad) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: An experimental polarization modulation infrared reflection absorption  spectroscopy setup was developed and built for studying the characteristics of  benzotriazole and other corrosion inhibitors at metal surfaces as a function of electrode  potential and pH. A thin film of imidazole was detected at a Au (111) single crystal  electrode surface using this setup, demonstrating its capability for application for  quantitative analysis.  The isotropic optical constants for benzotriazole, imidazole and benzimidazole  were determined for several spectral regions of interest. These regions were chosen based  on the presence of strongly absorbing bands which could be related to transition dipoles  and consequently to the molecular geometry of these soluble surfactants. The absorption  bands measured agree well with literature spectra and band assignments.

abstract: Chemistry


title: Implementing efficient copwin strategies on copwin graphs

contributor:
Shan, Shidong (author)
(Diamond, Jim) (Thesis advisor)
(Clarke, Nancy) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: The game of cops and robber is a pursuit game played on a reflexive graph. This  game has gained a lot of research interest recently due to its applications such as  searching for intruders on the Internet. This thesis summarizes the characterization  of copwin graphs and investigates different approaches for the copwin strategies.  The objective of this thesis is to develop some efficient copwin strategies on copwin  graphs. In addition, we have implemented and compared three different copwin  strategies, including optimal graph searching techniques, graph retraction mapping,  and a combination of both graph searching and retracting techniques.  vi

abstract: Computer Science


title: Investigation of the potential role of relaxin-3 in steroidogenesis in the ovarian follicles of Fundulus heteroclitus

contributor:
Burnett, Dave A. (author)
(Wilson, Brian) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: Recent immunohistochemical evidence suggests that relaxin-3 (RLX3) and one  of its receptors (GPCR135) are expressed in the ovary of the killifish, Fundulus  heteroclitus. However, nothing is known about the role of RLX3 in teleost fish.  The purpose of this study was to investigate the potential effect of RLX3 on 17-  estradiol synthesis in killifish ovarian follicles. Follicles were extracted from the  ovaries of thirteen female killifish and separated into three developmental stages:  vitellogenic, early-maturing and late-maturing. These follicles were then  incubated for 24 hours in medium-199 under five culturing conditions: a treatment  with no hormones (negative control), a human chorionic gonadotropin treatment  (positive control), and three treatments of human RLX3 at 1x10-9 M, 1x10-8 M,  and 1x10-7 M. The concentration of 17-estradiol in the culture supernatant was  then measured with an enzyme immunoassay using a polyclonal estradiol  antiserum. Although 17-estradiol concentrations were elevated in early-maturing  follicles treated with RLX3, this effect was found to be non-significant upon  statistical examination (P>0.05). The observed elevation in 17-estradiol  concentrations in early maturing follicles parallels the immunohistochemical  staining for RLX3 and GPCR135 observed mainly in follicles of mid to late  developmental stages.

abstract: Biology


title: Stratigraphy, depositional setting, and volcanism of the Letete Formation, Southwestern New Brunswick

contributor:
Lowe, David G. (author)
(Van Wagoner, Nancy) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: This thesis interprets the geology and lithogeochemistry of part of the Silurian  Letete Formation in southwestern, New Brunswick, based on detailed mapping of a 910-  m thick section, petrographic analysis of 52 thin sections, and major and REE  geochemistry of 11 samples.  The mapped Letete section generally represents a shoaling upward sequence. The  section is subdivided into three parts. The lowest contains an upward shoaling sequence  of subaqueously emplaced mafic pillow flows, pillow breccias, and sheet flows, overlain  by subaerially emplaced sheet flows that are interbedded with Surtseyan-style  phreatomagmatic tuffs. The middle section contains black and grey siltstones interbedded  with felsic volcaniclastic rocks indicating pulses of volcanism separated by periods of  relative quiescence. The shallowest water depths occur at the upper 50 m of the section  represented by a mafic tuff interpreted to be the result of a shallow water Surtseyan-style  eruption. The upper section contains black siltstones interbedded with increasing volumes  of felsic volcaniclastic rocks and overlain by massive grey siltstones that are interpreted  to record a shoaling upwards deltaic sequence with increasing felsic volcanism. At the  top of this section a 360-m thick section of massive and bedded felsic tuff is interpreted  to represent steady plinian and waning pulses of subplinian volcanism.  Processes of fractionation and crustal contamination account for the decreasing  Mg#, increasing ratio of LILE/MORB, and decreasing HFSE/MORB upward in the  section. The rocks are bimodal, and the mafic rocks have a within-plate geochemical  affinity consistent with the interpretation that volcanism occurred during extension  continental rift. This rift may have been the back-arc to the Kingston arc.

abstract: Earth & Environmental Sciences


title: Screen-based media use, physical activity level and body mass index of children and youth in Nova Scotia

contributor:
McNally, Danielle L. (author)
(Murphy, René) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2006

abstract: There is an increasing trend towards overweight and obesity in children and youth  in North America. This trend has typically been associated with poor nutritional  practices and reduced physical activity. Certain leisure time activities such as the number  of hours of television viewing, playing video games and internet/computer use have also  been implicated. Objective: The goal of this project was to assess the relationships  between objectively measured physical activity, BMI, and screen-based media use.  Participants: We studied a large, random sample of male and female grade 3, 7 and 11  (n=1643) students in the province of Nova Scotia. Design/Setting: A child/youth  questionnaire was administered to gather information on media use of participants.  Height and weight were recorded for each participant and an accelerometer was worn for  7 consecutive days. Results: Physical activity to achieve health benefits (defined as 60  minutes or more of moderate to vigorous physical activity 5 or more days per week) in  this population decreased significantly between grades 3 and 7 and females were  particularly at risk. The use of media increased with age but did not always relate  significantly to physical activity levels or BMI in this population. Conclusion: Leisure  time pursuits including television viewing and screen-based media use in general, do not  seem to have the direct relationships with physical inactivity and increasing BMI that  have previously been reported.

abstract: Kinesiology


title: A moth's memory: The effects of Octpamine on memory acquisition and retention in Heliothis Virescens Fabricius (Lepidoptera: Noctuidae)

contributor:
Chiddenton, Kathleen L. (author)
(Hillier, Kirk) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: Octopamine (OA) is an important chemical in invertebrates acting similarly to epinephrine and norepinephrine in vertebrates. OA has an important behavioural role in motivation, sensory sensitivity, as well as in reinforcement of learned behaviours. The purpose of this study was to determine the effects of OA on learning and memory as well as to test the importance of physiological state in relation to recall through a learning assay, the proboscis extension reflex ( PER). Comparisons of learning ability with and without OA injections were made in Heliothis virescens. Moths were trained in 8 conditioning trials and their memory was tested both 45 minutes and 24 hours post- training. During conditioning and recall, moths were placed in front of an air flow and when odour was released, their antennae were stimulated with a drop of sugar water and they were fed briefly. During memory recall trials, sugar water stimulus was not used. Those that performed PER towards odour without antennal stimulation were considered to have learned the association between the odour and the sugar water reward. It was found that OA had a significant impact on PER percentage in moths both during training trials as well as during initial recall at 45 minutes. During 24 hour recall, the memory significantly decreased, however moths injected with a second dose of OA showed increased memory. This provides evidence for the importance of state- dependent learning in memory recall and is a critical first step in understanding further the effects of OA in other areas such as weight loss, alcohol tolerance, and hypertension.

abstract: Biology


title: To explore women's career progression experiences and decisions in light of the persistence of a wage gap in academic ranks

contributor:
Lewis, Leslie (author)
(Grant, James) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: The purpose of this study was to investigate the effects of a gender wage gap on the career motivations and perceptions of women in academia. I became interested in this topic because previous research has largely overlooked the emotional effects of a gender wage gap and associated discrimination on women in academia. As a result, this study focuses on the discovery of changes in career motivations, job satisfaction and affection a woman has for herself, her career and her employing institution as a result of gender inequality in academia.  Interviews were used to meet the objectives of the study because of their unique ability to capture the lived experiences of the respondent ( Prasad, 2005). The interviews were analyzed using Prasad‘ s ( 2005) women‘ s voice perspective which uses women‘ s experiences to paint a vivid picture of how particular events have shaped their responses, motivations and perspectives. McCracken‘ s ( 1988) long interview approach was used to create an interview where the women could share their unique experiences and opinions of gender inequality in academia. The interviews were analyzed using the constant comparative method ( Strauss & Glasser, 1967) where each transcript is compared to the transcripts of other respondents to recognize likenesses and differences between responses.  The women‘ s interview responses showed differences in the way women and men experience the academic environment. The women were also aware that this difference was caused by gender discrimination. The women felt that gender based discrimination ix  by male colleagues and by their institution via reward structures was not intentional, was done without malice and was very subtle in nature. The women felt that their institutions were insensitive to their values when it came to balancing work with family responsibilities and meeting the needs of their students and department at the expense of working on their scholarship. The women actively organized informal networks and formal committees to advance women‘ s interests on campus and create support for women experiencing difficulty in all faculties. Overall, the women demonstrated guilt in reference to working outside the home, self- doubt of their work in relation to their male colleagues, and frustration that their commitment to service was not recognized by their institution as a meaningful contribution.

abstract: Business


title: Is it who I am or who I'm with that counts?: The associations between runner and group identity on adjustment to running group disbandment

contributor:
Glassford, Ainsley M. (author)
(Shields, Chris) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: Identity ( ID) theory views ID’s as the roles individuals hold ( e. g. wife, runner)  and ID- related expectations impact behaviour and social- cognitions ( an exerciser engages  in exercise). Social ID theory is concerned with IDs relating to group membership and  how such group- identification impacts behaviours and cognitions. While research has  shown that those with stronger role IDs felt more able to self- regulate in the face of a  behavioural challenge the impact of role IDs on other social- cognitions and the impact of  group- based IDs in dealing with such a challenge have not been examined. Therefore  there is a need for a study examining whether relational perceptions act as determinants  of identity formation and whether perceptions of ability to deal with behavioural  challenges are a function of personal identities and group- based identities.

abstract: Kinesiology


title: From the ground up

contributor:
Boucher, Tyler P. (author)
(Campbell, Wanda) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: This collection of poems draws on my personal experiences as a  farmhand to provide a fresh voice to the agrarian and pastoral tradition, as  influenced by the works of poets like Wendell Berry, Gary Snyder, Henry  David Thoreau, Harry Thurston, and William Wordsworth. It melds ideas  about humans’ relationship with the earth into a unique poetic interpretation  that echoes heightened cultural awareness about environmentalism and local,  small- scale farming. I have made use of a variety of styles, including the  iconograph, the list poem, and the haiku, as well as others. In addition to  experimenting with styles, I have taken a dual media approach to creative  writing by incorporating a series of ten photographs, which complement the  poems by providing a visual representation of farming and my experiences  working with the earth.

abstract: English & Theatre Studies


title: Muscle activity patterns of the upper limb and trunk during accelerated and constant maximum velocity sledge hockey propulsion

contributor:
Chisholm, Lisa (author)
(Landry, Scott) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: The aim of this study was to use surface electromyography ( EMG) to describe  the muscle activity patterns of selected trunk and upper extremity muscles during  accelerated and constant velocity sledge hockey propulsion. 15 healthy and active  male athletes performed forward sledge hockey propulsion while surface EMG was  used to measure muscle activity patterns of the latissimus dorsi ( LAT), teres major  ( TMA), posterior deltoid ( PDT), anterior deltoid ( ADT), triceps brachii ( TRI), biceps  brachii ( BIC) and pectoralis major ( PMA). EMG data was MVC ( maximum voluntary  contraction) normalized and then RMS ( root mean square) magnitudes were  compared between an accelerated and constant velocity stride for both the ground  contact and swing phases using a one‐ way repeated measures ANOVA. Muscle  activity levels were greater for the constant maximum velocity stride than the  accelerated stride. LAT demonstrated the greatest difference in magnitude between  the 2 strides ( p < 0.001). Comparisons between strides for all other muscles in  ground contact and swing showed significant differences ( p < 0.05), except for BIC  during swing that only approached significance ( p = 0.061). Muscle activity levels  were greater for the constant maximum velocity stride than the acceleration stride.  LAT, TMA and TRI, produced the highest activity levels during the first portion of  ground contact for both strides to move the arm and elbow into extension as the  pick of the stick was brought down to the ice and pulled back to generate forward  propulsion. PDT, ADT, BIC and PMA, produced the highest activity levels during the  first half of swing for both strides, to initiate shoulder flexion and return the  shoulder to the starting position in preparation for ground contact.

abstract: Kinesiology


title: Capital Health Nova Scotia surveillance of community associated methicillin resistant Staphylococcus aurues

contributor:
Hughes, Curtis Q. (author)
(Bell, Colin) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: Staphylococcus aureus is a Gram positive spherical pathogen which is responsible for a  wide variety of infections, including nosocomial infections, skin and soft tissue  infections, and necrotizing pneumonia. The advent of penicillin type drugs in the 1940’ s  brought about a novel method of S. aureus infection treatment, however, by 1961 S.  aureus isolates were confirmed to be resistant to this form of antibiotic. Termed  Methicillin Resistant Staphylococcus aureus ( MRSA), this new superbug quickly  established itself as a highly drug resistant opportunistic pathogen with a tendency to  prey on the sick and immune compromised. Originally believed to be a hospital-associated  pathogen, a more aggressive and virulent strain of this superbug was isolated  from the community in 1981. Since the discovery of this community associated MRSA  ( CA- MRSA), CA- MRSA strains have been popping up all over the world in an  increasing and alarming fashion. The purpose of this study was to determine the rate of  CA- MRSA among all MRSA isolates collected within the Capital Health Nova Scotia  region in order to survey the rapid growth of this highly virulent pathogen. Four hundred  and eighty six isolates of MRSA were collected from January 2008 – September 2008  and were tested for the Panton Valentine Leukocidin ( PVL), a common CA- MRSA  indicator, using the Polymerase Chain Reaction. The isolates that tested positive for PVL  were then typed using Pulsed Field Gel Electrophoresis ( PFGE) to determine their  specific strain. This data collection provides important information to the further  understanding of the epidemiological patterns of CA- MRSA. The results of these tests  showed that 12.14% of all MRSA isolates in the Capital Health Nova Scotia region are  CA- MRSA. These findings show an increase in the percentage of CA- MRSA in this  ix  region. Furthermore, these findings highlight that the extremely high rate of CA- MRSA  ( 21%) previously found in Cape Breton, Nova Scotia ( District 8) is not consistent with  the Capital Health region. Future research is important to determine the reason for the  high rate in Cape Breton, as well as to continue monitoring the quickly growing virulent  pathogen.

abstract: Biology


title: A federal failure: The health and well-being of indigenous women in Canada

contributor:
Crew, Mallory M. N. (author)
(Alexander, Cynthia) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: In traditional indigenous societies, women were considered to be ― health guardians‖; in the contemporary Canadian state, they are dually discriminated against on the basis of both race and gender, and consistently marginalized and oppressed. The disproportionately poor health and well- being of indigenous women in Canada is indicative of the federal government‘ s disinterest in the plight of indigenous peoples. The lingering legacy of colonialism continues to dominate federal policy and funding mechanisms, as manifested in the cognitive nearsightedness continually displayed by the federal government, mostly recently in the form of the federal 2010 budget. Health is a central starting point of equality, with significant implications for a broad span of positive change, from education to employment. The health of indigenous women is central to the health of indigenous communities. Further, the treatment of women is inherently connected to the treatment of the indigenous population. Without eliminating the foundations of sexism upon which Western society so comfortably rests, indigenous women will continue to suffer the pervasive effects of dual discrimination, and indigenous communities will continue to be divided and disadvantaged. Given the aging of the general Canadian population, and the rapidly increasing indigenous population, Canada has an important opportunity to finally acknowledge and build upon the strength and resilience of indigenous women. The federal failure to do so is a reflection of its continued colonial mindset.

abstract: Politics


title: An examination of the Canadian mortgage broker industry

contributor:
Williams, Andrew T. (author)
(VanBlarcom, Brian) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: This thesis seeks to answer the question “ why are mortgage brokers relatively under used in Canada and what could be gained from increasing their usage?” Through examination of the current market, mortgage brokers were found to be impeded by a combination of the following factors: broker inexperience, a history of fraud, the major bank’s dominance of advertising and consumer opinion, and the established status quo bias amongst Canadians. A third degree price discrimination model was subsequently used to estimate the consumer cost of these impediments. The consumer surplus cost was calculated to be $ 41.2 million in 2009. Individually, consumers can benefit from the use of mortgage brokers but the mortgage industry as a whole benefits from the decrease in dead weight loss, calculated to be $ 15.89 million. It is the existence of these savings that will likely encourage growth in this industry in the future.

abstract: Economics


title: A survey of the antennal sensilla of Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae)

contributor:
MacKay, Colin A. (author)
(Hillier, Kirk) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: The brown spruce longhorn beetle ( BSLB), Tetropium fuscum ( Fabr.), is an  invasive species introduced to Canada from Europe. The first specimens were collected  from Point Pleasant Park in Halifax, Nova Scotia in 1990, but were originally  misidentified as a native species. It was not until nine years later, in 1999, that the beetle  was confirmed and correctly identified in the park. In its native habitat, the BSLB usually  infests dead and dying trees, whereas in its new environment in Nova Scotia it has begun  infesting apparently healthy trees, primarily red spruce. A multi- agency governmental  task force was set up to combat the spread of the BSLB in Halifax. Research to date has  focused on the development of pheromone- based monitoring and mating disruption,  though an increased understanding of this species’ sensory physiology and morphology is  required. The purpose of this survey was to gather information about the distribution of  three different types of antennal sensilla and investigate whether there was sexual  dimorphism in terms of those distributions. Sensilla are hair- like sensory organs that  project from the cuticle on many different parts of an insect’s body. Three types were  examined: mechanoreceptors, olfactory receptors, and contact chemoreceptors. Antennae  were examined using a scanning electron microscope and micrographs were taken from  different angles to ensure a 360- degree view. The images were then examined using  image- processing software. Results did not indicate any significant sexual dimorphism in  terms of distribution of any of the three sensillar types examined, although a significant  correlation was found between the size of an antennal segment and the density of sensilla  present. This was purely a morphologically based survey, although preliminary  transmission electron microscopy has been performed for future study.

abstract: Biology


title: Watching that diet & getting on those genes: Epigenetic modifications and developmental plasticity in the spionid polychaete Polydora cornuta

contributor:
Hart, Corban R. B. (author)
(Gibson, Glenys) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: Many organisms exhibit developmental plasticity, whereby the environment  affects development and generates alternate phenotypes in young. The developmental  mechanisms that lead to this plasticity are largely unknown. My hypothesis is that  epigenetic modifications (e.g., histone methylation) lead to changes in gene transcription  during embryonic development that result in alternate phenotypes, and that these  modifications are altered by environmental factors such as diet. The spionid polychaete  Polydora cornuta is an excellent model for this investigation: these worms produce two  distinct larval morphs within a single egg capsule. Adelphophagic young are large, quick  to develop, and eat non-developing nurse eggs within the capsule, whereas planktotrophic  young are small, slow to develop, and eat plankton only after hatching. My objective was  to use immunofluorescence to screen for several epigenetic modifications throughout  development in the two larval morphs. Furthermore, I tested for changes in epigenetic  modifications in young whose mothers were fed diets rich in methyl donors (e.g.,  folate/vitamin B12). Major results included: (1) variation in onset and distribution of some  epigenetic modifications (e.g., H3K14 acetylation) among different tissues throughout  development, suggesting a link with cell differentiation; (2) earlier onset of one  modification (H3K9 monomethylation) in planktotrophic larvae; and (3)  hypermonomethylation (e.g., of H3K9) in young produced by females fed enhanced diets.  These results indicate that changes in the onset and distribution of specific epigenetic  modifications at certain ontogenetic stages may lead to developmental plasticity, and that  these modifications may indeed be influenced by maternal diet.

abstract: Biology


title: Joseph Howe: Principle and pragmatism

contributor:
Bennett, Adam J. (author)
(Henderson, Stephen) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: This thesis examines Joseph Howe and his role in this history of Confederation both as an opponent of Confederation and his abandonment of the repeal movement to negotiate for improved financial terms with the federal government of Sir John A. Macdonald. The core argument more specifically is that from his initial involvement with the Anti- Confederates to his entrance to Macdonald‘ s cabinet Howe‘ s actions were influenced by: a desire to protect the interests of Nova Scotia, a belief in the value of the British Empire, and pragmatism.  The thesis has been organized along two chronological divisions with chapters two and three each dealing with a specific time period. Chapter two examines Howe‘ s Botheration Letters, selections of his correspondence, and his proposed organization of the Empire will be examined as they provide clear examples of Howe‘ s motivation and arguments he utilized in opposition to Confederation. The third chapter deals with Howe‘ s response to the British North America Act becoming law and how he progressed from a stance of outspoken opponent of Confederation to federal cabinet minister. From this the thesis‘ primary focus is presented, that Howe‘ s actions as both opponent and supporter of Confederation were consistent and driven by principle and vision while being tempered by pragmatism.

abstract: History & Classics


title: MCL-1 promotes neurogenesis and survival of embryonic neural precursor cells in the mammalian brain

contributor: (Vanderluit, Jacqueline) (Thesis advisor)

subject: LE3 .A278 2010

abstract: The neural precursor population, from which neural cells are derived, is tightly regulated by cell division and cell death ( apoptosis). Myeloid cell leukemia- 1 ( Mcl- 1) is an anti- apoptotic member of the Bcl- 2 family which acts at the initial stages of apoptosis. Recent work with Mcl- 1 conditional knockout mice revealed that Mcl- 1 is required for the survival of embryonic Nestin positive neural precursor cells. These cells include both neural progenitor cells and neural stem cells. In this research project, I considered whether Mcl- 1 was a survival factor specifically for mammalian embryonic neural stem cells. To address this question, both loss- of- function and gain- of- function strategies were employed. The in vitro neurosphere assay revealed that Mcl- 1 conditional knockout embryos had significantly fewer self- renewing neural precursor cells, suggesting that Mcl- 1 is a survival factor for embryonic stem cells. In utero electroporation was employed to examine Mcl- 1 gain- of- function in vivo. Enhanced Mcl- 1 protein was observed in only a few cells and was compartmentalized within the cell in brains electroporated with the Mcl- 1 plasmid. In contrast, transfection with mutant Mcl- 1 plasmid ( proteasome- resistant) enhanced Mcl- 1 protein levels in all transfected cells demonstrating that protein levels are regulated by the proteasome. 48 hours after electroporation there was a 2- fold increase in transfected cells that had exited the cell cycle and migrated to the cortical plate in mutant Mcl- 1 transfected brains compared to control. Furthermore, Mcl- 1 gain- of- function resulted in a 3- fold increase in newborn neurons in the developing cortex within 48 hours. These results show that Mcl- 1 is tightly regulated and functions to promote both survival and neurogenesis in the embryonic neural precursor population.

abstract: Biology


title: The sacred vampire: The presence of Christianity within the vampire narrative and Bram Stoker’s Dracula

contributor:
Law, Larissa A. (author)
(Saklofske, Jon) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: The current cultural obsession with the vampire phenomenon is acknowledged by many  literary critics and theorists as beginning with the publication of Bram Stoker’s Dracula  in 1897. Although Christian beliefs and practices play a prominent role within Stoker’s  narrative, most critical responses to the novel overlook its importance. The integral  relationship between Christianity and the vampire is illuminated through the interplay of  supernatural and superstitious aspects within Dracula. In addition, the protagonists’ use  of occult practices promotes an alternative method of relating to Christianity in the late  Victorian era. Stoker’s attempt to eliminate superstitious fear is confirmed not only  through close readings, but also via an argument against Christopher Herbert’s concern  about the negative effects of superstition on Christianity within the novel. In opposition  to the suggestion that Dracula erodes Christian beliefs and practices both through the  vampire and through the strategies used to defeat the vampire, Stoker’s novel instead  reconfirms the continuing necessity and evolution of Christian belief within a  scientifically sceptical and progressive Victorian culture. More importantly, the  continuing popularity and influence of Stoker’s vampire preserves this Christian  perspective beyond its Victorian context.

abstract: English & Theatre Studies


title: Informed medical decision making by example of the Gardasil® vaccination program in Canada

contributor:
Bazak, Stephanie J. (author)
(MacLeod, Peter) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: The present study was an exploratory investigation of different factors associated with  young females’ decisions to receive the HPV vaccine, Gardasil ® or not in a sample of  Acadia University students. Although no formal hypotheses were made, several  expectations based on previous literature were made and supported. Results indicated that  relative to those who were not inoculated ( N= 61), those females who received ( N= 41) the  vaccine: were more likely to have spoken with their doctor, had support from their  families, had fewer concerns about the vaccine and were more knowledgeable about the  vaccine and HPV and reported greater decision satisfaction. Those individuals who  planned to get vaccinated but had not yet ( N= 29) were found to be consistently in  between the two other groups on most factors.

abstract: Psychology


title: Sous les yeux d'un espion: échapper à la surveillance dans les pièces de Molière

contributor:
MacCormac, Katherine Anne (author)
(Worvill, Romira) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2010

abstract: Dans les pièces de Molière où on trouve une figure autoritaire comme personnage  principal, le thème de la surveillance se présente sous la forme d’un système de pouvoir  qui met certains personnages dans une position inférieure dans l’hiérarchie sociale. La  figure autoritaire exerce un contrôle suprême sur les autres, ce qui crée une tension entre  les personnages. Très souvent, la volonté de la figure autoritaire risque de détruire le  bonheur affectif des personnages marginaux et du bien- être de la famille. C’est pour cette  raison qu’on trouve dans ces pièces des personnages qui sont obligés de chercher des  moyens subversifs pour trouver leur bonheur et régler le problème de la présence de la  figure autoritaire. Très souvent, la solution se manifeste sous la forme du théâtre dans le  théâtre, une stratégie qui permet aux personnages marginaux de duper la figure autoritaire  et renverser les relations du pouvoir. C’est ce renversement du pouvoir qui est central au  thème global de la surveillance parce qu’il nous offre une critique très intéressante de la  part du dramaturge du phénomène du pouvoir absolu exercé à l’époque et il nous donne  aussi une perspective sur la condition de certains membres de la société, surtout celle des  jeunes filles et des femmes. En prenant la théorie de Georges Forestier sur le théâtre dans  le théâtre et l’idée du « Panopticon » social de Michel Foucault, cette étude vise à  analyser les divers moyens subversifs que les personnages marginaux utilisent pour se  révolter contre ce système du pouvoir et de la surveillance et de montrer que même  Molière, dans ses pièces de théâtre, utilise des moyens subversifs pour faire une critique  universelle des structures de pouvoir qui existe dans la société.  « Le monde est un théâtre sous le regard de Dieu, et la vie une comédie aux cent actes  divers dont l’homme est l’acteur et le spectateur, ignorant le rôle véritable que Dieu lui a  assigné »

abstract: Languages & Literatures


title: Fecundity of Atlantic sturgeon (Acipenser oxyrinchus) from the Saint John River, New Brunswick

contributor:
Mitchell, Sarah (author)
Acadia University (Degree grantor)
(Stokesbury, Michael) (Thesis advisor)

subject: LE3 .A278 2019

abstract: Biology

abstract: Sturgeon species are known for their relatively high fecundity; however, the fecundity of Atlantic Sturgeon Acipenser oxyrinchus Mitchill, 1815 in the Saint John River is currently unknown. Fecundity is important for understanding life history, modeling population dynamics and determining conservation status. Atlantic Sturgeon are protected in most areas and the Saint John River, New Brunswick, supports one of the two remaining fisheries for Atlantic Sturgeon in Canada, along with the St. Lawrence River. The objectives of this study were to quantify the fecundity of female Atlantic Sturgeon in the Saint John River and determine the relationships between fecundity and fish weight, length, and age. Sixty prespawning mature female Atlantic Sturgeon were sampled in the Saint John River for total length, weight, age, gonad weight, gonadosomatic index and fecundity during July 2018. Atlantic Sturgeon age ranged from 27 to 48 years, determined by counting the annulipresent in pectoral fin spine sections. Absolute fecundity ranged from 153, 630 to 1, 306, 626 eggs, with a mean fecundity of 582, 832 eggs. Absolute fecundity exhibited a significant (p< 0.05) positive relationship with body weight.


title: The rise of self-efficacy: patient-partner efficacy dynamics in a cardiac rehabilitation context

contributor:
Petersen, Meaghan (author)
Acadia University (Degree grantor)
(Holmberg, Diane) (Thesis advisor)

subject: LE3 .A278 2019

abstract: Psychology

abstract:
This thesis, completed in response to rising incidences of heart disease, is part of a larger study of factors predicting successful outcomes following participation in a cardiac rehabilitation program involving both patients and their support partners. Data were collected using self-report surveys, along with 6-minute walk test results collected by hospital staff. In this study, both self-efficacy (i.e. belief in one’s self) and relation-inferred self-efficacy (RISE; i.e. the perceptions the patient has of their partners belief in them) were examined to determine how they relate to outcomes and whether agreement between the two variables predicts better outcomes overall. Main hypotheses stemming from the previous literature include: (a) higher self-efficacy and RISE will both be related to better outcomes; (b) congruency between self-efficacy and RISE will be associated with better outcomes, particularly when the congruence is found at higher levels of self-efficacy and RISE; and (c) should there be discrepancy between the variables, higher RISE will be associated with better outcomes. The data were analyzed using polynomial regression with response surface analysis with two separate outcome variables of self-reported exercise and 6-minute walk test. Results pertaining to the 6-minute walk test were not statistically significant.
With self-reported exercise as the outcome variable, (a) correlational results were insignificant, and thus could not establish a relationship between levels of RISE and self-efficacy and outcomes; (b) a trend was evident wherein increased congruency between levels of self-efficacy and RISE was marginally associated with improved self-reported (p=.09). When there was a
discrepancy, contrary to expectations, (c) it was found that outcomes were significantly better when self-efficacy levels surpassed those of RISE(p=.05). This research contributes to the wider literature on efficacy dynamics and congruence in eliefs. Further, it has the potential to inform clinical programs in the future and opens the door to a variety of avenues for further research in various clinical and sport contexts.


title: Application of the paleolimnological method in the environmental assessment of pulp mill effluent-influenced freshwater sediment in Pictou County, Nova Scotia

contributor:
Holmes, Baillie E.J. (author)
Acadia University (Degree grantor)
(Spooner, Ian) (Thesis advisor)
(Lake, Craig) (Thesis advisor)
(Walker, Tony) (Thesis advisor)

subject: LE3 .A278 2018

abstract: Earth & Environmental Sciences

abstract:
A former estuary in Pictou Co., Nova Scotia began receiving effluent in 1967 from a pulp mill. In 1972 a dam was installed, and the estuary was transformed into a freshwater pond. A  paleolimnological  approach  was  applied  to  the  bulk  geochemical  assessment  of  the sediment that has accumulated at the site. This study focused on the organic sediment that has accumulated since 1972 and identifying the sources of metals that were identified as representative  of  impact  at  the  site.  Samples  were  obtained  by  gravity  coring,  and  bulk geochemical analysis was accomplished using pXRF, carbon (C), nitrogen (N) and stable isotope analyses. Sediments were also obtained from a nearby freshwater lake and parallel analyses provided baseline reference concentrations for all bulk geochemical parameters. Data was analyzed in R and plotted using QGIS. At both the receiving pond and reference site,  metal  concentrations  generally  exceeded  Interim  Sediment  Quality  Guidelines;  a strong local geogenic and atmospheric contribution is inferred. Chromium was identified
as  a  metal  uniquely  representative  of  industrial  activity  at  the  site  and  may  be  a  good indicator  for  effectiveness  of  remediation  efforts.  Metal  concentrations  were  generally highest  at  the  top  of  the  receiving  pond  sediment  and  may  be  indicative  of  increasing effluent influence through time. Total C,  N and stable isotope data indicated dominantly
terrestrial organic input indicating that the receiving pond sediment is anomalous and may strongly influence the retention of metals. Results of this study demonstrate that geogenic and local atmospheric contribution to metal load at contaminated sites must be determined if site assessment, remediation and rehabilitation techniques are to be effective.


title: Behind closed doors: the stories and experiences of siblings of persons with mental illness

contributor:
Sparling, Rachel (author)
Acadia University (Degree grantor)
(Warner, Alan) (Thesis advisor)

subject: LE3 .A278 2019

abstract: Community Development

abstract:
When one or more sibling in a family has a mental illness, the siblings’ relationship with each other can be impacted in various ways. While there is some quantitative research that looks at the impacts the mental illness has on well siblings, there is very little that explores their stories and experiences through qualitative research.
The purpose of the study was to explore the narratives of sibling’s of persons with mental illness; start to understand the benefits and challenges that come with the well sibling experience; and to explore the ways in which well sibling’s relationships with their families are impacted by their relationship with their sibling with mental illness. The research was done through two qualitative semi-structured interviews and photo-elicitation pieces with five well siblings from Ontario and Nova Scotia between the ages of twenty and twenty-three.
The study found that the participants often had challenging relationships with their siblings and experienced fear, guilt, and anger because of their experiences. Participants also expressed changes in their family dynamics and their relationships with their parents. They showed empathy, understanding, and growth, highlighting that the well siblings are dynamic and act as important supports in their families. The finding also touched on the problems with labelling siblings as well and unwell and the need for better supports for siblings.


title: An investigation of allelic diver diversity of the major histocompatibility complex class II DRB gene in the American black bear, Ursus americanus, in Nova Scotia and New Brunswick.

contributor:
Sabean, Micaela L. (author)
Acadia University (Degree grantor)
(Stewart, Donald) (Thesis advisor)
(Coombs, Melanie) (Thesis advisor)

subject: LE3 .A278 2019

abstract: Biology

abstract:
It is extremely important to understand the genetic health of animal populations, especially large game mammals that are frequently hunted to implement appropriate management and conservation measures. The objectives of this study were to optimize polymerase chain reaction primers targeting the MHC class II DRB gene, to determine if there is allelic diversity in this gene, and to assess the population genetic health of the American black bear, Ursus americanus. The Major Histocompatibility Complex (MHC) is part of the adaptive immune system and is responsible for pathogen recognition by the peptide binding region (PBR). The allelic diversity of MHC, a non-neutral marker, more accurately assesses population health than neutral markers, such as microsatellites, which are not selected for. Primers were taken from the literature to target the MHC class II DRB and DQB genes. The URSDRB and URSDQB primer sets successfully amplified sequences with high similarity to DRB and DQB genes in other Ursus species. The PCR products of the DRB gene were cloned into plasmids and transformed into competent cells. However, the cloning of the PCR products into plasmids was not successful, although transformation of the plasmids into the JM109 competent cells was successful. In another set of experiments, the cloning and transformation of plasmids into TOP10 competent cells was also unsuccessful. It is necessary to separate the different alleles in the PCR products to obtain a nucleotide sequence. As an alternative to the methods used here, it should be possible to sequence the alleles without separation using next-generation sequencing techniques. With the allelic diversity of the MHC class II DRB gene the population genetic health can be assessed, and appropriate management
strategies can be implemented.


title: Comparing the effects of acute aerobic exercise on cognition in older adults

contributor:
Stefko, Karly N. (author)
Acadia University (Degree grantor)
(Mekary, Saïd) (Thesis advisor)

subject: LE3 .A278 2020

abstract: Kinesiology

abstract:
In a rapidly aging Canadian society, the prevalence of chronic disease has become a major health concern. With a large number of the population be over the age of 55, Canada is experiencing a surge of age-related declines in cognitive functioning including memory, attention, and processing speed, with an increase in cognitive disorders, such as Alzheimer’s. Pharmaceutical options have been explored, however, this is placing a
cost-burden on the Canadian Healthcare System. Safe and cost-effective alternatives need to be implemented to reduce this burden and improve overall quality of life.
It is well-known that regular physical activity has immense physiological and psychological benefits. Aerobic training, in particular, can improve central and peripheral aspects of cardiorespiratory fitness. It has also been found that moderate and high intensity aerobic exercise can improve cognitive functioning in older adults, specifically executive function. This is important for slowing cognitive decline, as executive function is the first aspect of cognition to deteriorate, but it is also the first to improve with exercise.
An acute bout of high intensity interval exercise (HIIE) and moderate intensity continuous training (MICE) have been found to improve cognitive function in older adults, however the appropriate intensity and duration
remains unclear, as well as the mechanisms explaining these improvements. This study is looking to investigate the differences in cognitive performance following an acute bout of HIIE and MICE, with the aim of discovering the safest and most promising dose-response relationship to slow cognitive decline.


title: Plasticity of pheromone chemistry and female olfactory sensitivity in the tobacco budworm moth Heliothis virescens

contributor:
Kelbratowski, Kassandra (author)
Acadia University (Degree grantor)
(Easy, Russell) (Thesis advisor)
(Hillier, Kirk) (Thesis advisor)

subject: LE3 .A278 2020

abstract: Biology

abstract:
Autodetection is a term used in insect pheromone communication to describes the ability of females to detect their own conspecific sex pheromone blend. The importance of autodetection to calling, spacing and other mating-related behaviour in the family Heliothinae is a recently emerging field of study, and as such the molecular mechanisms involved in the regulation of heliothine autodetection remain poorly understood. The objectives of this study were to examine the response of antennal olfactory receptors (ORs) following to pheromone exposure in female moths, and to examine if changes in antenna OR expression were related to
changes in pheromone gland OR expression or pheromone composition. Individual female Heliothis virescens moths were isolated and subjected to 18-hour exposure to either the minor component of their pheromone
blend, (Z)9-14:Ald, or to a hexane control. The pheromone blends of moths exposed to (Z)9-14: Ald had a slightly decreased ratio of (Z)11-16: Ald to (Z)9-14: Ald, from 5.31 to 3.83, as measured by relative amounts of
both compounds measured by chromatography. The expression of OR6 was found to have increased in the antenna tissue samples, and decreased in the pheromone gland tissue samples. The results suggest that in female heliothine moths, pheromone exposure may influence OR expression on the antenna as well as in other tissues, which may subsequently influence pheromone production and related behavioral outcomes in mating.


title: It's getting hot in here: does being social affect the thermal tolerance of an amphibious mangrove fish, Kryptolebias marmoratus

contributor:
Horton, Katie (author)
(Currie, Suzie) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2020

abstract:
As climate warming progresses, aquatic species are at risk if they cannot adapt to their new, warmer reality. We know tropical species are more vulnerable to climate warming than their temperate counterparts because their physiological thermal limits are perilously close to their environmental temperature. Living this close to one’s thermal limits results in a narrower thermal safety margin (TSM), which can impact species fitness. Notably, a fish’s social environment may influence how it responds to high temperature. Using an amphibious tropical fish, the mangrove rivulus, I hypothesized that sociability would negatively affect physiological and behavioural responses to increasing water temperatures. I used four distinct social situations: (1) a fish in isolation (control), (2) pairs, (3) groups of three, and (4) an isolated fish with a mirror. I measured the temperature at which fish emerged from heated water and their thermal tolerance (critical thermal maximum). I predicted that fish in social environments (i.e. mirror, pairs and threes) would emerge from water at a higher temperature, closer to their thermal limits, compared to isolated fish. My results showed that fish socially stimulated with their mirror reflection, had the highest emersion temperature compared to
all groups, but that fish in pairs, had the widest TSM. This finding suggests that paired fish may be at a thermal advantage compared to other groups. Furthermore, I discovered a correlation between higher emersion
temperature and an increase of approaches, as well as a correlation between a lower TSM and increase of approaches. Overall, my findings suggest there may be a relationship between bolder fish engaging in more social stimulation, resulting in a narrower TSM for these fish, but further examination is needed to confirm this relationship. This study gives some insight into how social stimulation can affect a rivulus’ response to ecologically relevant warming temperatures. This information is crucial for the conservation of species living close to their thermal optimum.

abstract: Biology


title: Investigating the effect of arbuscular mycorrhizae on Crocanthemum canadense (L.) Britt. (Cistaceae) propagated in tissue culture

contributor:
Sampson, Kendra (author)
Acadia University (Degree grantor)
(Evans, Rodger) (Thesis advisor)
(Walker, Allison) (Thesis advisor)

subject: LE3 .A278 2020

abstract: Biology

abstract:
Crocanthemum canadense(L.) Britt. (Cistaceae), Rockrose, is a small perennial herb found in Eastern North America sand barrens. It is classified as critically imperiled in Nova Scotia under the Nova Scotia Endangered Species Act. Nova Scotia Rockrose populations continue to decline; recent counts estimate only 5000-5500 plants remain. To better understand Rockrose biology, we analysed symbiotic mycorrhizal associations among native Nova Scotia populations. Recent research from our group has documented the presence of arbuscular mycorrhizal fungi (AMF) within Rockrose roots of plants in their native habitat; the present study is the first to focus primarily on the benefits of this symbiotic relationship between Rockrose and AMF, and to identify the fungal partner. AMF improve water and nutrient uptake (phosphorus and nitrogen) by the plant. In return, they rely on the plant as a host and carbon source. In a greenhouse trial with varying percentages of AMF inocula, we determined how AMF would affect the growth of Rockrose plants propagated from tissue culture. The 1:25 inoculum had the most significant effect on the height of the shoots (cm) while the 1:50 inoculated plants had the largest root mass (g). Previous studies indicate that the lack of phosphorus in the experimental trial could have had a negative effect on the growth and symbiosis of C. canadense and AMF. The identity of AMF in the roots and the inoculum was determined using rDNA barcoding. A potentially novel species of AMF sister to Funneliformis mosseae was identified. This research will aid in the conservation and restoration of this critically imperiled species by further understanding
beneficial soil fungi, an understudied component of the declining sand barrens habitat.


title: “Open wide!" effects of air and hydrogen sulphide acclimation on buccal cavity tissue structure in an amphibious fish

contributor:
Wells, Kyle Richard Douglas (author)
Acadia University (Degree grantor)
(Gibson, Glenys) (Thesis advisor)
(Currie, Suzie) (Thesis advisor)

subject: LE3 .A278 2020

abstract: Biology

abstract: Phenotypic plasticity occurs in many organisms and supports the development of alternate phenotypes in different environments. Mangrove rivulus (Kryptolebias marmoratus) is a neotropical amphibious fish exposed to high concentrations of hydrogen sulphide, normally toxic, in its mangrove environment. This fish can be aerially exposed for months and is capable of cutaneous respiration, a plastic trait, supplemented by air gulping. We tested the effects of air (3d, 7d) and 3d aquatic hydrogen sulphide (H2S) exposure on the tissue structure of the buccal cavity (mouth) and skin, and specifically, on the number of mucus cells.  Results demonstrated a significant increase in the number of mucus cells in the buccal cavity epithelium in the 3 and 7-day air acclimation, as well as in the 3-day H2S group.  No significant differences in mucus cells were detected in the skin (epidermis) when the fish were exposed to 3 and 7 days of air acclimation, or to the 3-day H2S acclimation. This study suggests that tissues of the buccal cavity acclimate quickly to air and aquatic H2S and supports the hypothesis that air gulping is an important behaviour during aerial exposure.


title: Mercury and other metals in sediment, cattails, and invertebrates from Hyla Park and the surrounding wetland, in Fredericton, New Brunswick

contributor:
Bonga, Laura L. (author)
Acadia University (Degree grantor)
(O’Driscoll, Nelson) (Thesis advisor)
(Gray, Michelle) (Thesis advisor)

subject: LE3 .A278 2020

abstract: Earth & Environmental Sciences

abstract:
Mercury (Hg) is a trace element that can be distributed by both anthropogenic and natural sources into ecosystems worldwide. Hg can bioaccumulate and biomagnify in aquatic food webs leading to toxic effects in ecosystems at high concentrations. Hyla Park (Fredericton, NB) and the surrounding wetlands may have mercury and other metals entering the wetland from an adjacent metal recycling facility. This research examines the distribution and concentration of mercury (Hg) and several metals in surface sediment, macrophytes, and aquatic invertebrates. Aquatic macroinvertebrates, sediment, and cattail roots were collected from eight sites within Hyla Park and the surrounding wetland. The samples were dried, homogenized and analyzed for total mercury (THg) and other metals with thermal degradation –atomic absorbance and X-Ray
fluorescence. Twenty-two aquatic invertebrate families were identified and organized by functional feeding group. THg concentration in predatory invertebrates (n=65; mean=78.72 ng/g dw) was significantly (p<0.01)
higher than the herbivorous invertebrates (n=34; mean=28.12 ng/g dw), and THg in piercing predators (n=18; mean=134.45 ng/g dw) was significantly (p<0.01) higher than in swallowing predators (n=46; mean=57.68 ng/g dw). Within the sediment there was a positive linear correlation between percent loss on ignition and THg concentrations in the sediment, and a significant positive rise to a maximum relationship between THg and iron concentrations in the sediment. The THg in the sediment had no significant relationship to the THg in associated invertebrates within Hyla Park and the surrounding wetland.  Lead, copper, zinc, and Hg concentrations in sediment were above the Canadian sediment quality guidelines at some sample locations. The metals found to be above guidelines, and the potential for Hg bioaccumulation in aquatic invertebrates within Hyla Park and the surrounding wetland, may pose a risk to higher trophic level organisms.


title: Exploring the phenomenon of filamentation in Listeria monocytogenes

contributor:
Muntz, Laura Porter (author)
Acadia University (Degree grantor)
(Ells, Tim) (Thesis advisor)
(d'Entremont, Hélène) (Thesis advisor)

subject: LE3 .A278 2020

abstract: Biology

abstract:
Listeria monocytogenes is an opportunistic food-borne pathogen which displays tolerances to a plethora of stress factors, that allows it to persist in harsh environments. Listeria monocytogenes strain Lm568, originally isolated from a food processing environment, was exposed to cold and acid stress and subsequently developed colonies with atypical morphology relative to its wild type. Further examination of the cells from these colonies under the microscope revealed an elongated phenotype. Filamentation is a stress response that has been documented in a variety of bacteria, including L. monocytogenes when subjected to difficult conditions. However, little is known about the relevance of this state in the context of food safety. For example, do these filamented cells form septa and revert to normal cells, thereby increasing the infected dose if
ingested. If not, what is the virulence capacity of the cells in the elongated state. In this study experiments were performed to shed light on these questions. A virulence assay, microscopy, growth kinetic assays, and
other characterization tests were applied to wild type strain Lm568 (Lm568WT) and its filamemented phenotype (Lm568F) with the aim of assessing the risk Lm568F could pose as a food pathogen compared to its
wild type counterpart. Filamentation in this strain of L.monocytogenes appears to result in less virulence, despite the mutant being just as metabolically active as the original Lm568WT strain. During this study, a morphological variant, distinguishable by its short-curved rod morphology,was found to have derived from samples of Lm568F, suggesting this strain is able to revert from the filamented state under certain stress conditions. Overall, this variant named Lm568D, also appears to be less virulent than Lm568WT and may pose less of a risk to food safety than Lm568WT.


title: Identifying fungal associations of the endangered plant Crocanthemum canadense (L.) Britt. (Cistaceae) in Nova Scotia

contributor:
Byers, Philicity R.M. (author)
Acadia University (Degree grantor)
(Walker, Allison) (Thesis advisor)

subject: LE3 .A278 2019

abstract: Earth & Environmental Sciences

abstract:
Crocanthemum canadense (L.) Britt. (Cistaceae) is a small, herbaceous plant that is critically imperiled in Nova Scotia. Habitat loss and an insect pest, Mompha capella (Momphidae), are contributing to population decline. The role of fungal
associations in C. canadense populations is unknown, and thus the primary goal of this research was to identify fungal symbionts to aid in propagation and conservation strategies. Fungi were isolated from the roots, stems, and leaves of C.
canadense plants collected throughout six sites at 14 Wing Canadian Forces Base Greenwood, Nova Scotia. Arbuscular mycorrhizal fungi (AMF) were observed using root staining and microscopic techniques to determine percent root colonization. Site 3 had the highest average A MF colonization rate (53%; n = 3). Using ITS rDNA barcoding, 43 fungal species were identified from roots, 14 from leaves, 6 from upper stems, and 11 from lower stems. Six ascomycete fungi occurred in more than half of the study sites and colonized more than a third of the plants sampled. These included Pyrenophora tetrarrhenae colonizing 89% of plants which was isolated from above-ground tissues, Arcopilus aureus (56%; from all
tissue types), Pilidium concavum (50%; from roots, leaves, and lower stems), Phialocephala cf. fortinii (44%; from roots and lower stems), Apiognomonia cf. hystrix (39%; from all tissue types), and Sphaeronaemella fragariae (39%; only from leaves).
Apiognomonia cf. hystrix and P. tetrarrhenae were present in C. canadense tissue at all six sites. This research provides
the first report of the fungal relationships potentially influencing endangered Nova Scotia C. canadense populations and could be used to enhance the success of future plant propagation and conservation efforts.