Thesis advisor: Donnah Canavan / Abstract Energy is an emerging concept in social psychology. Baumeister et. al., likening energy to a muscle, have defined exertion of self control as an energy depleting behavior. Energy depletion is measured by reduced performance on a subsequent self-control task. In contrast, Canavan's work on social energy focuses on energy generation and replenishment. Social energy is produced when two or more people are intrinsically interested in the same thing and form a satisfying relationship over this interest. Individuals high in social energy exert more effort, persist longer, and perform better. The present study was conducted in a 2x2 ANOVA design with Social Energy and Depletion as the independent variables and persistence and performance as the dependent variables. Participants worked in groups of two or three groups and were randomly assigned to conditions. In High Social Energy, they imagined managing The Beatles. In the No Social Energy, they imagined managing a cover band playing Beatle's songs. The participants then performed either a depleting or non-depleting proofreading task. Afterwards, the dependent variables were assessed in several tasks: a handgrip task and a measure of creativity and persistence. The results indicate: (1) no significant effect of depletion on the handgrip task and (2) no significant effect of social energy on any of the behavioral measures (i.e. handgrip task or creativity measure). In conclusion, the results did not support either the Depletion or Social Energy behavioral predictions. In the questionnaire data differences between Social Energy and No Social Energy showed significantly higher energy states, social energy, intrinsic motivation, flow, and most important more effort and hard work. The study does improve upon former Social Energy studies in terms of its conceptualization because it successfully manipulated No Social Energy and presented a more sophisticated conceptualization of energy. The manipulations of Social Energy and Depletion interfered with each other making it impossible to test the hypotheses. Paper to be presented at the annual Psychology Honors Conference, Psychology Department, Boston College, Chestnut Hill, Massachusetts, May 2005. / Thesis (BS) — Boston College, 2005. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Psychology. / Discipline: College Honors Program.

In their natural environments microorganisms exist predominantly in aggregates and biofilms. The ability of bacteria to form aggregates is associated with the biosynthesis of polymers such as polysaccharides. In this study the physical mechanisms underlying bacterial aggregation by extracellular polysaccharides are investigated by utilising the bacterium Sinorhizobium meliloti. S. meliloti biosynthesises an extracellular polysaccharide called succinoglycan, which is well characterised in terms of its structure and biosynthesis. A range of previously constructed succinoglycan biosynthesis mutants were screened for altered aggregation. An S. meliloti exoS mutant (a gain of function mutation that results in a constitutively active two component regulator called ExoS) overproduces succinoglycan and has enhanced aggregation compared to the parent strain, Rm1021. The aggregates settle to the bottom of the culture vessel resulting in loss of turbidity of the cultures and phase separation. Microscopic observation showed that succinoglycan did not appear to be attached to the aggregates, which formed ordered structures of laterally aligned cells. By addition of purified succinoglycan it was found that the critical concentration of polymer required to induce aggregation and phase separation of the cultures decreased with increasing cell concentration. These observations suggest that aggregation of S. meliloti cultures in the presence of succinoglycan is driven by macromolecular crowding, otherwise known as depletion attraction. Depletion attraction can drive the ordered arrangement and aggregation of colloidal particles in the presence of polymers. Aggregation of the particles increases the volume available to the polymers, maximising their entropy and the entropy of the system. Addition of succinoglycan to stationary phase Escherichia coli cultures and polystyrene colloids also resulted in aggregation consistent with depletion attraction. Furthermore alternative polymers such as the bacterial extracellular polysaccharide xanthan produced by Xanthomonas campestris can result in aggregation of bacteria by depletion attraction. Depletion attraction may therefore be a ubiquitous force driving aggregation of crowded dispersions of bacteria and polymers. The second part of the thesis focuses on how depletion driven aggregation can lead to surface-associated biofilm formation. Imaging of the sediment formed by the exoS mutant showed that the structure formed at the base of the culture vessel leads to development of an ordered structure composed of interlinked aggregates. The role of succinoglycan in surface attachment is complex and varies with culture conditions. Depletion attraction may facilitate interaction with a surface but alternative factors may then play a role in anchoring the cells to the surface. Under certain conditions the cells may produce factors which allow binding of the cells to a surface independently of succinoglycan. This study has demonstrated for the first time that an extracellular polysaccharide produced by bacteria can result in aggregation via depletion attraction which may be an under explored mechanism by which aggregation of bacteria can occur.

As mitocôndrias são organelas semiautonômicas, portadoras do próprio DNA, o mtDNA e responsáveis pela produção de energia celular na forma de ATP, através do processo de fosforilação oxidativa. Atualmente, diferentes tipos de doenças, como distrofias musculares e diversos tipos de câncer, estão associadas à alteração nas moléculas de mtDNA. Na década de 70 um modelo a partir do cultivo celular com brometo de etídio (EtBr) foi desenvolvido com o objetivo de se criar uma linhagem celular depletada de cópias de mtDNA. Desde então os mais variados estudos foram realizados e diversos tipos celulares foram submetidos à depleção do mtDNA. Este projeto teve como objetivos criar um modelo de cultivo celular somático na espécie bovina com depleção de cópias de mtDNA para investigar a resposta da célula a esta condição; avaliar como as células depletadas se comportam na ausência de EtBr, além da utilização destas células no processo de reprogramação celular por indução gênica na tentativa de avaliar o efeito do numero de cópias de mtDNA na indução na espécie bovina. Para tanto foram desenvolvidos três experimentos; Experimento 1- Depleção de mtDNA a partir da utilização do brometo de etídeo; Experimento 2 Repleção do mtDNA; e Experimento 3 Utilização de células bovinas depletadas no sistema de reprogramação nuclear. Todos os experimentos foram avaliados quanto a quantidade de cópias de mtDNA e expressão gênica para os genes Bax, Bcl2 e Tfam. Ademais, os experimentos 1 e 2 foram avaliados quanto a viabilidade celular e apenas o experimento 1 foi avaliado quanto ao crescimento e morfologia celular. O experimento 1 foi avaliado durante o cultivo celular nos períodos D0, D4, D7, D10 e D13, com os grupos experimentais controle (EtBr-C) e tratado com 100 ng/mL de brometo de etídio (EtBr-T), quanto a núero de cópias do mtDNA, o grupo EtBr-T diferiu do grupo EtBr-C (P=0,0459), apresentando menor número de cópias de mtDNA; menor taxa crescimento celular (P<0,05), porém sem alteração na morfologia celular, e na expressão dos genes descritos acima. No experimento da repleção, não houve diferença no número de cópias de mtDNA, entre os grupos EtBr-T e EtBr-R, indicativo de que as células atingiram o estado rho 0 ou que necessitam de mais tempo para ativar a replicação do mtDNA; quanto a viabilidade celular, houve diferença entres os grupos, quanto a expressão gênica, com aumento do Bax e do Bcl-2 para o grupo EtBr-T; O grupo EtBr-R apresentou queda do Bcl-2; para o Tfam houve aumento para o grupo EtBr-T e uma queda para o grupo EtBr-R. Quanto ao experimento 3, não foi possível observar sinais de pluripotência, porém foi detectada uma queda na quantidade de mtDNA dos dois grupos tratados por EtBr (EtBr com e sem Stemcca) e o grupo controle com Stemcca. Para analise de expressão gênica, não houve diferenças entre os grupos em relação ao Tfam. Quanto ao Bax, os grupos controle com Stemcca, controle sem Stemcca e EtBr sem Stemcca não diferiram, e o ultimo também não apresentou diferença quando comparado ao grupo EtBr com Stemcca. Para o Bcl-2, os grupos controle sem Stemcca e EtBr com Stemcca não apresentaram diferenças entre si; o grupo controle sem Stemcca não apresentou diferença quando comparado aos grupos controle com Stemcca e EtBr sem Stemcca. Concluindo, este trabalho no nosso conhecimento, descreve pela primeira vez a produção de células bovinas Rho 0 e discute sobre a relação da função mitocondrial e o processo de reprogramação celular. / Mitochondria are semi autonomic organelles which present their own DNA (mtDNA); are in charge of cell energy production as ATP through oxidative phosphorylation. Currently, different types of diseases like muscular distrofy; different types of cancer are associated to alterations of mtDNA molecules. In the 70\'s a model based on cell culture with ethidium bromide (EtBr) was developed in order to create a cell line depleted of mtDNA. Since then, a variety of studies were realized; diverse cell types were submited to mtDNA depletion. This project had as objective creating a model of somatic cell culture in bovine species with depletion of mtDNA copies, in order to investigate cell response to this condition; to analyze depleted cell behavior in the absence of EtBr, besides using this depleteded cell in a reprogramming cell process by genic induction in order evaluate the effect of the number of mtDNA copies during induction in bovine species. Therefore three experiments were developed: Experiment-1 Depletion of mtDNA using ethidium bromide. Experiment-2 repletion of mtDNA; Experiment-3 usage of depleted bovine cells in reprogramming nuclear system. Cell experiments were analyzed according to the quantity of mtDNA copies; genic expression for Bax, BCl2; Tfam genes. Also, experiments 1; 2 were analyzed on cell viability; only experiment 1 was analyzed regarding cell morphology; growth. Experiment-1 was analyzed during cell culture on periods D0, D4, D7, D10, D13, with control experimental groups (EtBr-C),; treated with 100 ng/mL ethidium bromide (EtBr-T); relating to mtDNA quantification the EtBr-T group differed from EtBr-C (P=0,0459) presenting a smaller number of mtDNA copies; smaller growth rate (P<0,05); although there was no differences on cell morphology as there was also no difference related to genic expression of the previous stated genes. Repletion experiment showed no differences about the number of mtDNA copies between EtBr-T; EtBr-R groups, indicating this cells reached Rho0 state or that they need more time to activate mtDNA replication; about cell viability, there were no differences among the groups; relating to genic expression there was an increase of Bax; BCl-2 for EtBt-T group; EtBr-R group showed decrease of BCl-2; for Tfam there was an increase for EtBr-T group; a decrease for EtBr-R. Relating to Experiment-3 it was impossible to notice signs of pluripotency, but we could see a decrease in the amount of mtDNA in both groups treated with EtBr (EtBr with; without STEMCCA) as in control group with STEMCCA. Genic expression analysis didn\'t show differences related to Tfam. Regarding to BAX, both control groups (with; without STEMCCA); EtBr without STEMCCA didn\'t differ from each other,; the last one also didn\'t show any difference when compared to EtBt with STEMCCA group. For BCl-2, control group without STEMCCA; EtBr with STEMCCA didn\'t show differences among each other; control group without SEMCCA didn\'t show differences when compared to control group with STEMCCA; EtBr without STEMCCA. Concluding, this work, regarding our knowledge, describes for the first time, production of bovine Rho0 cells; debates about the relationship among mitochondrial function; the process of cell reprogramation.

A large body of research has demonstrated that the experience of romantic jealousy is often associated with a variety of negative outcomes. However, evolutionary psychologists have provided evidence that jealousy is an adaptive emotion that can aid with mate retention. Together these lines of research suggest that jealousy may at times work to protect and enhance one’s relationship, whereas in other cases it could lead to harmful consequences. Considering the varying outcomes of jealousy, it is critical that research explore more specifically how this complex state operates and how it affects individuals’ functioning. In the present research I conducted 2 separate studies in order to examine how jealousy is related to self-control. In Study 1 I used an online survey to examine how individuals’ trait self-control was related to their levels of chronic jealousy. Results showed that trait self-control was negatively associated with cognitive and behavioral jealousy but was not associated with emotional jealousy. Additionally, all 3 components of jealousy explained variance in self-control above and beyond the effects of self-esteem and rejection sensitivity. In Study 2 I used hypothetical scenarios in order to experimentally examine how imagined infidelity would impact individuals’ state self-control. Furthermore, based on research demonstrating sex differences in distress based on different types of infidelity, I examined how imagined sexual and emotional infidelity would differentially impact males’ and females’ state self-control. Using a 3 x 2 between-subjects design, participants from a primarily young adult sample were randomly assigned to 1 of 3 conditions: emotional infidelity, sexual infidelity, and a control. Afterward, state self-control was assessed through a behavioral task. Results showed no differences in state self-control based on condition and no difference between males and females based on type of infidelity. There was a main effect for sex, such that males generally showed higher self-control than females across all 3 conditions. Although the results demonstrate that chronic jealousy and trait self-control are associated constructs, the findings from Study 2 suggest that the experience of jealousy not does impact state self-control. Methodological concerns are addressed and future avenues are presented for researching how jealousy and self-control may be related.

Osteoporosis affects the human skeleton through the direct effects of the disease on the function and structure of bone. Individuals who are affected by osteoporosis may be subject to serious fractures and it is estimated that annually approximately 1.5 million fractures can be attributed to this disease [1]. The disease is categorized as the direct side effect of increased bone porosity and bone loss and is directly linked to estrogen deprivation [2]. Animal models are often used to make initial conclusions about the effects of the disease or pharmacological treatments. In this study, sheep were chosen as a representative animal model due to their similar metabolic characteristics to that of a human. Like most animals, the ovine does not undergo a natural menopause and an ovariectomy was necessary to replicate the condition. The study objective was to quantify compact bone density present in ovine at three months post ovariectomy. The study included 112 ovine separated into different treatment groups. The treatment groups were separated into 4 groups of 28 based on season of surgery: autumn, winter, spring, and summer. Each seasonal group was further divided into 2 groups of 14; the first group underwent an ovariectomy; and the second group underwent a sham surgery, in which the ovaries were visualized and handled but left in the abdomen. One group was sacrificed 3 months post operatively and the other group was sacrificed at 12 months post operatively. This study specifically looks at ewe sacrificed at 3 months. The radius from each sheep was cut into the anatomical sectors: cranial, caudal, craniolateral, craniomedial, caudomedial, and caudolateral. Each anatomical sector was turned into a microradiograph for analysis. Densitometry was performed to determine the density of each specimen using the estimated thickness of aluminum (ETA) as the key. Statistical analysis assessed the resulting data to understand the effects of treatment, season of sacrifice, season of surgery, and anatomical sector by comparing both mean ETA and standard deviation ETA to understand changes in bone density. The results revealed significant differences between the ovariectomy and sham groups as well as variation within season of surgery and season of sacrifice in both groups. Anatomical sector showed no significant variation. The differences in the thickness of aluminum seen in the sheep that underwent a sham operation can be attributed to the presence of estrogen. The sheep that underwent an ovariectomy showed differences in the estimated thickness of aluminum that can be attributed to other seasonal characteristics including the influence of Vitamin D. The results and conclusions within this study can be used to influence bone material characteristics and bone loss test protocols in future osteoporosis and estrogen depletion studies.

The purpose of this thesis was to compare the tensiometer and climatic methods of scheduling irrigation of potatoes under field conditions. Tensiometers were placed in a 160 acre field to maintain the crop within the optimum moisture range and schedule irrigations. An automatic solid set system was used to apply water to the potato crop. Instrumentation was used to determine daily input for the climatological method. Daily evapotranspiration (Et) was computed and Et (tensiometer) was comPared with Et (climatic). The results showed total variation of the climatic method from the tensiometer method of .62 inches or less than 5 per cent. The study indicated that the climatological method would have under irrigated the potato crop by . 62 inches during the 48 day study. Variations are also shown for each irrigation interval. Results indicated that a combination of both methods would allow the most feasible approach to scheduling irrigation of potatoes.

Polymers of various types are added to crude oils and oil products to prevent wax deposition, break water-in-oil emulsions, reduce drag in pipelines and to stabilize asphaltenes. In mixtures where a polymer does not adsorb on colloids, two stable liquid phases can arise due to depletion flocculation. Asphaltenes in heavy oils and toluene mixtures form sterically stabilized colloidal particles. In this work, the addition of a non-adsorbing polymer (polystyrene) to C5 Maya asphaltene + toluene mixtures was investigated experimentally and theoretically. As concentrated asphaltene + toluene mixtures are opaque to visible light, phase volumes and compositions were detected using ultrasound. The sensors comprised two commercial 64 element phased-array acoustic probes. The operation of the view cell, and kinetic and equilibrium data processing procedures were validated using mixtures of methanol + alkanes. Acoustic speed and attenuation profiles were found to provide independent measures of phase separation. At equilibrium, acoustic speed profiles are uniform in each phase with a step change at the interface. Acoustic wave attenuation profiles exhibit a sharp peak/spike at liquid-liquid interfaces. Mixtures of asphaltenes + polystyrene + toluene are shown to exhibit liquid-liquid phase behavior over broad ranges of composition. This is the first report of liquid-liquid phase behavior for such mixtures. One phase is asphaltene rich and the other phase is polystyrene rich. Liquid-liquid critical points were also identified along the liquid-liquid/liquid phase boundary for mixtures with two mean molar masses of polystyrene. Compositions of co-existing phases were computed using phase volume variations along dilution lines, acoustic speed data and a mass balance model. A parameter was introduced to improve the agreement between calculated and experimental speeds of sound. The results of the model indicate that more than half of the asphaltenes, by volume, participate in the depletion flocculation process. Phase compositions were measured independently using UV-visible spectrophotometry. The nominal size of asphaltene colloidal particles participating in the phase separation mechanism was estimated by comparing calculated phase boundaries with the experimental phase diagram. The estimated size of asphaltene colloidal particles is in agreement with the expected size of asphaltenes in toluene mixtures obtained exogenously. / Chemical and Materials Engineering

A ground-based, zenith-sky, UV-visible triple grating spectrometer was installed at the Polar Environment Atmospheric Research Laboratory (PEARL) in the Canadian High Arctic during polar springtime from 2004 to 2007 as part of the Canadian Arctic ACE (Atmospheric Chemistry Experiment) Validation Campaigns. From the solar spectra, ozone, NO2, and BrO vertical column densities (VCDs) have been retrieved using the DOAS (Differential Optical Absorption Spectroscopy) technique. This spectrometer, the UT-GBS (University of Toronto Ground-Based Spectrometer), was also deployed as part of the fourth Middle Atmosphere Nitrogen TRend Assessment (MANTRA) campaign in Vanscoy, Saskatchewan in August and September 2004. A near-identical spectrometer, the PEARL-GBS, was permanently installed at PEARL in August 2006 as part of the refurbishment of the laboratory by CANDAC (Canadian Network for the Detection of Atmospheric Change). Since then, the instrument has been making continuous measurements, with the exception of during polar night. Vertical columns of ozone and NO2 can be retrieved year-round. During the 2007 sunrise campaign, differential slant column densities (DSCDs) of OClO and VCDs of BrO were also retrieved. Ozone and NO2 DSCDs and VCDs from the UT-GBS were compared to the DSCDs and VCDs from three other UV-visible, ground-based, grating spectrometers that also participated in the MANTRA and Eureka campaigns. Two methods developed by the UV-visible Working Group of the NDACC (Network for the Detection of Atmospheric Composition Change) were followed. During MANTRA, the instruments were found to partially meet the NDACC standards. The comparisons from Eureka were an improvement on the MANTRA comparisons, and also partially met the NDACC standards. In 2007, the columns from the UT-GBS and PEARL-GBS were compared, and were found to agree within the NDACC standards for both species. Ozone and NO2 VCDs from the ground-based instruments were also compared to integrated partial columns from the ACE-FTS (ACE-Fourier Transform Spectrometer) and ACE-MAESTRO (ACE-Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) on board the ACE satellite. ACE-FTS partial columns were found to agree with the ground-based total columns, while the ACE-MAESTRO partial columns were found to be smaller than expected for ozone and larger than expected for NO2.

A ground-based, zenith-sky, UV-visible triple grating spectrometer was installed at the Polar Environment Atmospheric Research Laboratory (PEARL) in the Canadian High Arctic during polar springtime from 2004 to 2007 as part of the Canadian Arctic ACE (Atmospheric Chemistry Experiment) Validation Campaigns. From the solar spectra, ozone, NO2, and BrO vertical column densities (VCDs) have been retrieved using the DOAS (Differential Optical Absorption Spectroscopy) technique. This spectrometer, the UT-GBS (University of Toronto Ground-Based Spectrometer), was also deployed as part of the fourth Middle Atmosphere Nitrogen TRend Assessment (MANTRA) campaign in Vanscoy, Saskatchewan in August and September 2004. A near-identical spectrometer, the PEARL-GBS, was permanently installed at PEARL in August 2006 as part of the refurbishment of the laboratory by CANDAC (Canadian Network for the Detection of Atmospheric Change). Since then, the instrument has been making continuous measurements, with the exception of during polar night. Vertical columns of ozone and NO2 can be retrieved year-round. During the 2007 sunrise campaign, differential slant column densities (DSCDs) of OClO and VCDs of BrO were also retrieved. Ozone and NO2 DSCDs and VCDs from the UT-GBS were compared to the DSCDs and VCDs from three other UV-visible, ground-based, grating spectrometers that also participated in the MANTRA and Eureka campaigns. Two methods developed by the UV-visible Working Group of the NDACC (Network for the Detection of Atmospheric Composition Change) were followed. During MANTRA, the instruments were found to partially meet the NDACC standards. The comparisons from Eureka were an improvement on the MANTRA comparisons, and also partially met the NDACC standards. In 2007, the columns from the UT-GBS and PEARL-GBS were compared, and were found to agree within the NDACC standards for both species. Ozone and NO2 VCDs from the ground-based instruments were also compared to integrated partial columns from the ACE-FTS (ACE-Fourier Transform Spectrometer) and ACE-MAESTRO (ACE-Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) on board the ACE satellite. ACE-FTS partial columns were found to agree with the ground-based total columns, while the ACE-MAESTRO partial columns were found to be smaller than expected for ozone and larger than expected for NO2.

Current accounts of self-control are highly individualistic. When individuals succeed at exerting self-control, we assume that they possess some positive internal characteristic that explans their success. Similarly, when individuals do not succeed, we blame their failure on an internal flaw. Yet many factors may influence the likelihood that an individual will exert self-control, including not only internal characteristics of individuals but also external factors. In this dissertation, I develop a framework for understanding the multiple sources of influence on individuals' state self-control that groups these factors into three categories: social, personal, and environmental. Further, I detail the multiple mechanisms by which the factors in the Social, Personal, and Environmental Control of Self (SPECS) model may influence self-control. Specifically, I examine the potential role of regulatory accessibility as a mechanism of influence on state self-control. In Study 1, I show that individuals who think about a friend with good self-control demonstrate increased performance on a persistence task than do participants who think about a friend with bad self-control. In Study 2, I replicate this effect, showing increased inhibitory capacity among individuals who wrote about a friend with good self-control compared to a control group, and decreased inhibitory capacity among individuals who wrote about a friend with bad self-control. In Study 3, I show that regulatory exertion increases among individuals subliminally primed with the name of a friend with good self-control and that regulatory exertion decreases among indivdiuals primed with the name of a friend with bad self-control. These findings support my hypothesis that models of self-control should account for sources of influence external to the individual, as well as explore the multiple pathways by which regulatory exertion is influenced. These findings support my hypothesis that social factors influence regulatory exertion, or state self-control. Further, they provide evidence that state self-control is influenced not only by regulatory capacity, but also by other mechanisms, including regulatory accessibility. Further research following the SPECS model will investigate the combined influence of social and environmental influences on self-control and the indirect influences of personal characteristics, such as trait self-control, on regulatory exertion. / Dissertation