Ecological and evolutionary effects of dispersal on freshwater zooplankton

A recent focus on contemporary evolution and the connections between communities has sought to more closely integrate the fields of ecology and evolutionary biology. Studies of coevolutionary dynamics, life history evolution, and rapid local adaptation demonstrate that ecological circumstances can dictate evolutionary trajectories. Thus, variation in species identity, trait distributions, and genetic composition may be maintained among ecologically divergent habitats. New theories and hypotheses (e.g., metacommunity theory and the Monopolization hypothesis) have been developed to understand better the processes occurring in spatially structured environments and how the movement of individuals among habitats contributes to ecology and evolution at broader scales. As few empirical studies of these theories exist, this work seeks to further test these concepts. Spatial and temporal dispersal are the mechanisms that connect habitats to one another. Both processes allow organisms to leave conditions that are suboptimal or unfavorable, and enable colonization and invasion, species range expansion, and gene flow among populations. Freshwater zooplankton are aquatic crustaceans that typically develop resting stages as part of their life cycle. Their dormant propagules allow organisms to disperse both temporally and among habitats. Additionally, because a number of species are cyclically parthenogenetic, they make excellent model organisms for studying evolutionary questions in a controlled environment. Here, I use freshwater zooplankton communities as model systems to explore the mechanisms and consequences of dispersal and to test these nascent theories on the influence of spatial structure in natural systems. In Chapter one, I use field experiments and mathematical models to determine the range of adult zooplankton dispersal over land and what vectors are moving zooplankton. Chapter two focuses on prolonged dormancy of one aquatic zooplankter, Daphnia pulex. Using statistical models with field and mesocosm experiments, I show that variation in Daphnia dormant egg hatching is substantial among populations in nature, and some of that variation can be attributed to genetic differences among the populations. Chapters three and four explore the consequences of dispersal at multiple levels of biological organization. Chapter three seeks to understand the population level consequences of dispersal over evolutionary time on current patterns of population genetic differentiation. Nearby populations of D. pulex often exhibit high population genetic differentiation characteristic of very low dispersal. I explore two alternative hypotheses that seek to explain this pattern. Finally, chapter four is a case study of how dispersal has influenced patterns of variation at the community, trait and genetic levels of biodiversity in a lake metacommunity.

Moral standards of the Scotch-Irish ...

Thesis (A.M.)--University of Chicago (Dept. of Philosophy) 1913.

MEDIA IN THE ERA OF GLOBALIZATION IN LATIN AMERICA

Terms like Internet, cyberspace, virtual reality, in short, globalization, have been frequently words for all of us, in recent years. This refers to the phenomenon that has shaken the people of this world. Are rapidly changing due to technological advances and complex levels reaching relations between countries, corporations, partnerships and people.The attempt to understand the phenomenon of globalization is compounded when we try to understand the term, coined by Marshall McLuhan.McLuhan was born in Edmonton, Alberta, Canada and studied at the Universities of Manitoba and Cambridge, the latter of which he received his degree of Doctor of Philosophy specializing in English Literature. He taught at the universities of Wisconsin and St. Louis and University of the Assumption and Saint Michael's College, University of Toronto, where he was director of the Center for Culture and Technology.Marshall McLuhan and B. R. Powers, wrote the play, The Village Global1. The universe has become a village is the future predicted for them in the 60's. Today reality has overtaken the theory. However, this phenomenon is presented in this work, so whimsical style reminiscent of Jules Verne, but does not clarify the content of the term. While we believe that in the past there were attempts; globalize these attempts were very different from what we understand by globalization. 

Magnetic and Acoustic Investigations of Turbulent Spherical Couette Flow

Title of dissertation: MAGNETIC AND ACOUSTIC INVESTIGATIONS OF TURBULENT SPHERICAL COUETTE FLOW Matthew M. Adams, Doctor of Philosophy, 2016 Dissertation directed by: Professor Daniel Lathrop Department of Physics This dissertation describes experiments in spherical Couette devices, using both gas and liquid sodium. The experimental geometry is motivated by the Earth's outer core, the seat of the geodynamo, and consists of an outer spherical shell and an inner sphere, both of which can be rotated independently to drive a shear flow in the fluid lying between them. In the case of experiments with liquid sodium, we apply DC axial magnetic fields, with a dominant dipole or quadrupole component, to the system. We measure the magnetic field induced by the flow of liquid sodium using an external array of Hall effect magnetic field probes, as well as two probes inserted into the fluid volume. This gives information about possible velocity patterns present, and we extend previous work categorizing flow states, noting further information that can be extracted from the induced field measurements. The limitations due to a lack of direct velocity measurements prompted us to work on developing the technique of using acoustic modes to measure zonal flows. Using gas as the working fluid in our 60~cm diameter spherical Couette experiment, we identified acoustic modes of the container, and obtained excellent agreement with theoretical predictions. For the case of uniform rotation of the system, we compared the acoustic mode frequency splittings with theoretical predictions for solid body flow, and obtained excellent agreement. This gave us confidence in extending this work to the case of differential rotation, with a turbulent flow state. Using the measured splittings for this case, our colleagues performed an inversion to infer the pattern of zonal velocities within the flow, the first such inversion in a rotating laboratory experiment. This technique holds promise for use in liquid sodium experiments, for which zonal flow measurements have historically been challenging.

Diversity in Catalytic Reactions of Propargylic Diazoesters

Abstract Title of Document: Diversity in Catalytic Reactions of Propargylic Diazoesters Huang Qiu, Doctor of Philosophy, 2016 Directed By: Professor Michael P. Doyle, Department of Chemistry and Biochemistry Propargylic aryldiazoesters, which possess multiple reactive functional groups in a single molecule, were expected to undergo divergent reaction pathways as a function of catalysts. A variety of transition metal complexes including rhodium(II), palladium(II), silver(I), mercury(II), copper(I and II), and cationic gold (I) complexes have been examined to be effective in the catalytic domino reactions of propargylic aryldiazoesters. An unexpected Lewis acid catalyzed pathway was also discovered by using FeCl3 as the catalyst. Under the catalysis of selected gold catalysts, propargylic aryldiazoesters exist in equilibrium with 1-aryl-1,2-dien-1-yl diazoacetate allenes that are rapidly formed at room temperature through 1,3-acyloxy migration. The newly formed allenes further undergo a metal-free rearrangement in which the terminal nitrogen of the diazo functional group adds to the central carbon of the allene initiating a sequence of bond forming reactions resulting in the production of 1,5-dihydro-4H-pyrazol-4-ones in good yields. These 1,5-dihydro-4H-pyrazol-4-ones undergo intramolecular 1,3-acyl migration to form an equilibrium mixture or quantitatively transfer the acyl group to an external nucleophile with formation of 4-hydroxypyrazoles. In the presence of a pyridine-N-oxide, both E- and Z-1,3-dienyl aryldiazoacetates are formed in high combined yields by Au(I)-catalyzed rearrangement of propargyl arylyldiazoacetates at short reaction times. Under thermal reactions the E-isomers form the products from intramolecular [4+2]-cycloaddition with H‡298 = 15.6 kcal/mol and S‡298= -27.3 cal/ (mol•degree). The Z-isomer is inert to [4+2]-cycloaddition under these conditions. The Hammett relationships from aryl-substituted diazo esters ( = +0.89) and aryl-substituted dienes ( = -1.65) are consistent with the dipolar nature of this transformation. An unexpected reaction for the synthesis of seven-membered conjugated 1,4-diketones from propargylic diazoesters with unsaturated imines was disclosed. To undergo this process vinyl gold carbene intermediates generated by 1,2-acyloxy migration of propargylic aryldiazoesters undergo a formal [4+3]-cycloaddition, and the resulting aryldiazoesters tethered dihydroazepines undergo an intricate metal-free process to form observed seven-membered conjugated 1,4-diketones with moderate to high yields.

Timing and economic value of mergers and acquisitions

Doctor of Philosophy in the Faculty of Business Administration

Making the Men of Tomorrow: American Science Fiction and the Politics of Masculinity, 1965 – 1974

Suggesting that the political diversity of American science fiction during the 1960s and early 1970s constitutes a response to the dominance of social liberalism throughout the 1940s and 1950s, I argue in Making the Men of Tomorrow that the development of new hegemonic masculinities in science fiction is a consequence of political speculation. Focusing on four representative and influential texts from the 1960s and early 1970s, Philip K. Dick’s The Three Stigmata of Palmer Eldritch and Ubik, Robert A. Heinlein’s The Moon Is a Harsh Mistress, and Ursula K. Le Guin’s The Dispossessed, this thesis explores the relationship between different conceptions of hegemonic masculinity and three separate but related political ideologies: the social ethic, market libertarianism, and socialist libertarianism. In the first two chapters in which I discuss Dick’s novels, I argue that Dick interrogates organizational masculinity as part of a larger project that suggests the inevitable infeasibility of both the social ethic and its predecessor, social liberalism. In the next chapter, I shift my attention to Heinlein’s The Moon Is a Harsh Mistress as a way of showing how, unlike Dick, other authors of the 1960s and early 1970s sought to move beyond social liberalism by imagining how new political ideologies, in this case market libertarianism, might change the way men see themselves. Having demonstrated how the libertarian potential of Heinlein’s novel is ultimately undermined by its insistent and uncompromising biological determinism, I then discuss how Le Guin’s The Dispossessed uses the socialist libertarianism of the moon Anarres to suggest a more egalitarian form of masculinity, one that makes possible, to some extent at least, a future in which men might embrace not only the mutual aid of socialism, but also the primacy of individual rights that is at the heart of all forms of libertarianism and liberalism.

What's so funny? An evaluation of the relations among humour use, mirth, and depressive symptomatology

Humour production and showing mirth (i.e., smiling and laughing) confer prosocial advantages. However, there is a paucity of literature evaluating how humour manifests in psychopathology. Humour and mirth may be especially relevant in depression, wherein profound impairments are evident in emotional and social functioning. Chapters 2 and 3 present correlational and predictive relations of depressive, social anxiety, and social anhedonia symptoms with humour styles, and consider the role of motivational systems and expressivity of positive affect as they relate to humour. As expected, symptoms and avoidance-based motivation were positively related to maladaptive humour styles and negatively related to adaptive humour styles. Interestingly, the pattern of relations shifted when considered among individuals in a depressive episode; acutely depressed individuals generally shy away from any humour style rather than gravitating toward specific styles. In a mediation model, the inverse relation between depressive symptoms and affiliative humour was fully mediated by approach-based motivation and expressivity of positive emotions. Chapters 4 and 5 examined subjective and observed mirth responses (facial affect and laughter) demonstrated by depressed and healthy comparison groups. Relative to non-depressed individuals, depressed persons reported less enjoyment, lower ratings of funniness, and fewer instances and shorter durations of positive facial affect and laughter when viewing humourous videos. There was no significant change in retrospective ratings of enjoyment and funniness at a one-week follow-up. The pattern of responsivity by depressed persons shifted when they viewed humourous videos while hearing others laughing. Both groups demonstrated more mirth when hearing others laugh; there were no differences between groups on mirthful behaviours. The one exception was that the total duration of laugher produced by depressed individuals was shorter than that produced by individuals in the healthy comparison group. This research project demonstrates that facets of depressive symptomatology are differentially associated with humour use and depressed individuals show blunted emotional responsivity to humourous stimuli. However, the pattern of reduced affective responsivity is context specific in that it fluctuates in response to hearing others’ laughter. These findings have important implications for the conceptualization of depression and the subsequent avenues for the treatment of individuals with depression.

TOWARD A POLITICAL CONCEPTION OF MINORITY RIGHTS: RECONCILING SOVEREIGNTY, HUMAN RIGHTS AND MINORITY CLAIMS

The question that I will explore in this research dissertation is whether one can defend the rights of homeland minorities as a progressive extension of the existing norms of human rights. This question calls for several deeper inquiries about the nature, the function and the underlying justifications for both human rights and minority rights. In particular, this research project will examine the following issues: on what normative grounds the available norms of human rights and minority rights are justified; if there is any methodic way to use the normative logic of human rights to support substantial forms of minority claims, such as the right to self-determination; whether human rights can take the form of group rights; and finally, whether there is any non-sectarian basis for justifying the minority norms, which can be acceptable from both liberal and non-liberal perspectives. This research project has some implications for both theories of minority rights and human rights. On the one hand, the research employs the topic of minority rights to shed light on deficiencies of the existing political theories of human rights. On the other hand, it uses the political theory to shed light on how existing theories of minority rights could be improved and amended. The inquiry will ultimately clarify how to judge the merit of the claim that minority rights are or should be a part of human rights norms.

The Impact of Community Social Capital on the occurrence of Injuries in adolescents and falls in older adults: Population-based Studies Conducted in Canadian samples

The objectives of this thesis were to study specific Canadian populations in order to examine; (1) relationships between the neighbourhood-level social capital and injuries in youth, as well as (2) falls in older adults, and; (3) to address methodological issues relevant to the study of such relationships. The thesis is comprised of four manuscripts. The first addresses methodological issues surrounding the validation of neighbourhood-level variables for the study of adolescent health, and demonstrates the existence of structural confounding in the study of related etiological relationships. Informed by the latter, the second manuscript examines the association between neighbourhood-level social capital and injuries in youth, and demonstrates that lower levels of social capital are protective factors for girls but not for boys. Manuscript 3 uses an international database focused on older adults, and shows that our existing measure of social capital is valid at neighbourhood levels, but also that there is a high possibility for the existence of structural confounding among Canadian older adults. The fourth manuscript then examines the association between neighbourhood-level social capital and the occurrence of falls in older adults and determines that differences between neighbourhoods are important factors in the occurrence of falls, and that higher levels of social capital are a risk factor for falls. Taken together, results from this thesis provide a better understanding of the role of neighbourhood-level social capital on the occurrence of injuries in Canadian youth and on the occurrence of falls in older adults. Our contributions were important both methodologically and etiologically.

The SHIVir Survey: A Dynamical Catalogue of Virgo Cluster Galaxies and their Scaling Relations

By virtue of its proximity and richness, the Virgo galaxy cluster is a perfect testing ground to expand our understanding of structure formation in the Universe. Here, we present a comprehensive dynamical catalogue based on 190 Virgo cluster galaxies (VCGs) in the "Spectroscopy and H-band Imaging of the Virgo cluster" (SHIVir) survey, including kinematics and dynamical masses. Spectroscopy collected over a multi-year campaign on 4-8m telescopes was joined with optical and near-infrared imaging to create a cosmologically-representative overview of parameter distributions and scaling relations describing galaxy evolution in a rich cluster environment. The use of long-slit spectroscopy has allowed the extraction and systematic analysis of resolved kinematic profiles: Halpha rotation curves for late-type galaxies (LTGs), and velocity dispersion profiles for early-type galaxies (ETGs). The latter are shown to span a wide range of profile shapes which correlate with structural, morphological, and photometric parameters. A study of the distributions of surface brightnesses and circular velocities for ETGs and LTGs considered separately show them all to be strongly bimodal, hinting at the existence of dynamically unstable modes where the baryon and dark matter fractions may be comparable within the inner regions of galaxies. Both our Tully-Fisher relation for LTGs and Fundamental Plane analysis for ETGs exhibit the smallest scatter when a velocity metric probing the galaxy at larger radii (where the baryonic fraction becomes sub-dominant) is used: rotational velocity measured in the outer disc at the 23.5 i-mag arcsec^{-2} level, and velocity dispersion measured within an aperture of 2 effective radii, respectively. Dynamical estimates for gas-poor and gas-rich VCGs are merged into a joint analysis of the stellar-to-total mass relation (STMR), stellar TFR, and Mass-Size relation. These relations are all found to contain strong bimodalities or dichotomies between the ETG and LTG samples, alluding to a "mixed scenario'' evolutionary sequence between morphological/dynamical classes that involves both quenching and dry mergers. The unmistakable differentiation between these two galaxy classes appears robust against different classification schemes, and supports the notion that they are driven by different evolutionary histories. Future observations using integral field spectroscopy and including lower-mass galaxies should solidify this hypothesis.

Landscape Patterns of Permafrost Disturbance and Degradation in the Canadian High Arctic

Intensification of permafrost disturbances such as active layer detachments (ALDs) and retrogressive thaw slumps (RTS) have been observed across the circumpolar Arctic. These features are indicators of unstable conditions stemming from recent climate warming and permafrost degradation. In order to understand the processes interacting to give rise to these features, a multidisciplinary approach is required; i.e., interactions between geomorphology, hydrology, vegetation and ground thermal conditions. The goal of this research is to detect and map permafrost disturbance, predict landscape controls over disturbance and determine approaches for monitoring disturbance, all with the goal of contributing to the mitigation of permafrost hazards. Permafrost disturbance inventories were created by applying semi-automatic change detection techniques to IKONOS satellite imagery collected at the Cape Bounty Arctic Watershed Observatory (CBAWO). These methods provide a means to estimate the spatial distribution of permafrost disturbances for a given area for use as an input in susceptibility modelling. Permafrost disturbance susceptibility models were then developed using generalized additive and generalized linear models (GAM, GLM) fitted to disturbed and undisturbed locations and relevant GIS-derived predictor variables (slope, potential solar radiation, elevation). These models successfully delineated areas across the landscape that were susceptible to disturbances locally and regionally when transferred to an independent validation location. Permafrost disturbance susceptibility models are a first-order assessment of landscape susceptibility and are promising for designing land management strategies for remote permafrost regions. Additionally, geomorphic patterns associated with higher susceptibility provide important knowledge about processes associated with the initiation of disturbances. Permafrost degradation was analyzed at the CBAWO using differential interferometric synthetic aperture radar (DInSAR). Active-layer dynamics were interpreted using inter-seasonal and intra-seasonal displacement measurements and highlight the importance of hydroclimatic factors on active layer change. Collectively, these research approaches contribute to permafrost monitoring and the assessment of landscape-scale vulnerability in order to develop permafrost disturbance mitigation strategies.

ROLE OF THE FRONTAL EYE FIELD, SUPERIOR COLLICULUS, AND BASAL GANGLIA IN FLEXIBLE SACCADE BEHAVIOR

A distributed network of cortical and subcortical brain regions mediates the control of voluntary behavior, but it is unclear how this complex system may flexibly shift between different behavioral events. This thesis describes the neurophysiological changes in several key nuclei across the brain during flexible behavior, using saccadic eye movements in rhesus macaque monkeys. We examined five nuclei critical for saccade initiation and modulation: the frontal eye field (FEF) in the cerebral cortex, the subthalamic nucleus (STN), caudate nucleus (CD), and substantia nigra pars reticulata (SNr) in the basal ganglia (BG), and the superior colliculus (SC) in the midbrain. The first study tested whether a ‘threshold’ theory of how neuronal activity cues saccade initiation is consistent with the flexible control of behavior. The theory suggests there is a fixed level of FEF and SC neuronal activation at which saccades are initiated. Our results provide strong evidence against a fixed saccade threshold in either structure during flexible behavior, and indicate that threshold variability might depend on the level of inhibitory signals applied to the FEF or SC. The next two studies investigated the BG network as a likely candidate to modulate a saccade initiation mechanism, based on strong inhibitory output signals from the BG to the FEF and SC. We investigated the STN and CD (BG input), and the SNr (BG oculomotor output) to examine changes across the BG network. This revealed robust task-contingent shifts in BG signaling (Chapter 3), which uniquely impacted saccade initiation according to behavioral condition (Chapters 3 and 4). The thesis concludes with a published short review of the mechanistic effects of BG deep brain stimulation (Chapter 5), and a general discussion including proof of concept saccade behavioral changes in an MPTP-induced Parkinsonian model (Chapter 6). The studies presented here demonstrate that the conditions for saccade initiation by the FEF and SC vary according to behavioral condition, while simultaneously, large-scale task dependent shifts occur in BG signaling consistent with the observed modulation of FEF and SC activity. Taken together, these describe a mechanistic framework by which the cortico-BG loop may contribute to the flexible control of behavior.

PROLINE-BASED CHIRAL STATIONARY PHASES: INSIGHTS INTO THE MECHANISM OF CHIRAL SELECTIVITY

Proline (Pro) is a unique amino acid that has been examined previously as a potential chiral selector for high-performance liquid chromatography. In recent years, a new class of promising Pro based enantioselective stationary phases has been studied and the longer peptides were found to be competitive with commercial chiral stationary phases (CSPs). Here, we aim to perform a comprehensive examination of a t-butoxycarbonyl- (t-Boc-) terminated monoproline selector. This selector was grafted through an amide linkage to an aminopropyl siloxane-terminated Si (111) wafer and to a silicon atomic force microscopy tip. To ensure a flat, homogeneous overlayer of selectors suitable for force spectrometric measurements, the prepared surfaces were characterized using XPS, AFM and contact angle measurements. Chemical force spectrometry (CFS) has been used to examine the chiral discrimination in our monoproline CSP by measuring the interaction forces between two D- or L-monoproline monolayers in water and in the presence of a series of amino acids in solution to explore the degree to which binding of amino acids impacts self-selectivity. Chemical force titration (CFT) has been used to observe the influence of variations in pH on the binding interaction of proline modified chiral surfaces. Here we aim to explore the connection between side-chain hydrophobicity and differences in the nature of the binding between different ionic forms of amino acids and the t-Boc-Pro interface, and thereby to gain insight into the mechanism of chiral selectivity. The CFS results show several trends for different proline selector/amino acid combinations and indicate that the binding characteristics of amino acid to the proline surface is strongly dependent on the amino acid side chain where hydrophilic side chain amino acids exhibit a selectivity opposite to that seen for those with hydrophobic side chains. The CFT studies also provide valuable insights into interactions between the proline selector and the amino acids under a wide range of pH conditions, indicating that protonated amine groups of alanine and serine are closely involved in the binding mechanism to proline surfaces. On the other hand, the presence of the second carboxylic group in aspartic acid plays an important role while interacting with proline.

Study of the Electrochemical, Physical and Morphological Characteristics of Anode Catalysts for Perfluorosulfonic Acid (PFSA) Membrane Water Electrolysers

A number of supported and un-supported Oxygen Evolution Reaction (OER) iridium based electrocatalysts for Polymer Electrolyte Membrane Water Electrolysis (PEMWE) were synthesized using a polyol method. The electrocatalysts and the supports were characterized using a wide range of physical and electrochemical characterization methods. The effect of morphological characteristics of the OER electrocatalyst and the support on the OER activity was studied. The results of this thesis contribute to the existing research to reduce the cost of PEMWE by enhancing the utilization of precious metal for OER electrocatalysis. Iridium electrocatalysts supported on antimony tin oxide (Ir/ATO) were synthesized using the polyol method with two different heating techniques: conventional and microwave-irradiation. It was shown that the physical morphology and electrochemical properties of Ir/ATO synthesized with the two heating methods were comparable. However, the microwave irradiation method was extremely faster than the conventional heating method. Additionally, the effect of heat treatment (calcination temperature) on the morphology and OER activity of Ir/ATO synthesized electrocatalyst with the conventional polyol method. It was found that the iridium electrocatalyst synthesized with the polyol method, consisted of 1-5 nm particles, possessed an amorphous structure, and contained iridium with an average oxidation state of less than +4. Calcining the catalyst at temperatures more than 400 ºC and less than 700ºC: 1) increased the size of the iridium particles to 30 nm, 2) changed the structure of iridium particles from amorphous to crystalline, 3) increased the iridium oxidation state to +4 (IrO2), 4) reduced the electrochemically active surface area by approximately 50%, and 5) reduced the OER activity by approximately 25%; however, it had no significant effect on the physical and chemical morphology of the ATO support. Moreover, potential support metal carbides and oxides including: Tantalum Carbide (TaC), Niobium Oxide (Nb2O5), Niobium Carbide (NbC), Titanium Carbide (TiC), Tungsten Carbide (WC) and Antimony-doped Tin Oxide (ATO, Sb2O5-SnO2), were characterized, and used as support for the iridium OER electrocatalysts. TaC was found to be a promising support, and increasing its surface area by 4% improved the OER performance of the final supported catalyst by approximately 50%.