No description available.

The utility of hypervariable DNA polymorphisms as a general population genetics method was studied in three fish species by the use of multilocus DNA fingerprinting. Laboratory lines and field caught specimens from Belize and Florida of the clonal species <i>Rivulus marmoratus</i> were examined to determine the relative contributions of mutation and migration to genetic variation in the species. Specimens of <i>Poecilia latipinna</i>, the sailfin molly, from Florida and Georgia were used to explore the properties of hypervariable markers in the context of an outbred and abundant species that exhibits typical levels of genetic variability at nuclear loci. The results were compared to those of a previous allozyme survey of the same populations. Samples of <i>Morone saxatilis</i> from the Chesapeake Bay system were used to investigate the utility of hypervariable markers in the description of genetic variation of an outbred species depauperate in other measures of genetic variation. The results of this study indicate that variation observed among among <i>R. marmoratus</i> clones characterized by hypervariable loci may be the result of natural selection; based on the analyses of mutation rates and population structure. Results from the work with <i>P.latipinna</i> showed that hypervariable loci could have general utility as a method for studying population structure. This utility was demonstrated in the examination of Chesapeake Bay populations of <i>M. saxatilis</i>. Large degrees of interindividual variation at hypervariable loci permitted the characterization of population structure within Chesapeake Bay populations of this species. / Ph. D.

Aufgrund ihrer vielfältigen Anpassungen in Ökologie und Verhalten stellen die Carnivora eine geeignete Gruppe dar, um die Muster innerhalb der sozialen Evolution der Säugetiere zu studieren. Insbesondere Arten mit unterschiedlicher sozialer Organisation der beiden Geschlechter bieten die Möglichkeit, geschlechtsspezifische Kosten und Vorteile zu untersuchen, um die Determinanten und Mechanismen von Sozialität aufzuzeigen. Die Mangusten (Herpestidae) sind eine Gruppe kleiner Raubtiere, in der Studien zu einer kleinen Anzahl von hochsozialen Arten mit kooperativer Jungenaufzucht entscheidend zum Verständnis des Gruppenlebens und der Verteilung des Fortpflanzungserfolgs unter Gruppenmitgliedern bei Säugern beigetragen haben. Im Gegensatz dazu ist über die Sozialsysteme ihrer nächsten Verwandten, der Eupleridae (Madagassische Raubtiere) viel weniger bekannt. Diese Gruppe bietet jedoch ein großes Potenzial zur Untersuchung der Geschwindigkeit und Mechanismen der sozialen Evolution der Raubtiere in vergleichender Perspektive, weil sie sich für mehr als 20 Millionen Jahre isoliert auf Madagaskar entwickelt hat. In dieser Dissertation lege ich die soziale Organisation, Lebenslaufstrategie und genetischen Eigenschaften des madagassischen Schmalstreifenmungos (Mungotictis decemlineata) im Kirindy-Wald/CNFEREF, einem tropischen saisonalen Trockenwald im Westen Madagaskars, dar. Als Grundlage für zwischenartliche Vergleiche bewerte ich des weiteren in einer umfassenden Betrachtung den Wissensstand über die Sozialsysteme und Lebenslaufstrategien der Herpestiden und Eupleriden und setze diese in Beziehung zu den Vorhersagen sozio-ökologischer Theorie. Während meiner Feldstudien in den Jahren 2011 bis 2014 fing ich 63 Schmalstreifenmungos in Lebendfallen, vermaß und markierte diese und nahm Gewebeproben für genetische Untersuchungen. Von insgesamt 40 Individuen (20 Männchen, 20 Weibchen), die ich mit Radiosendern versehen hatte, sowie von den mit ihnen assoziierten Artgenossen sammelte ich durch systematische Radiotelemetrie und Zensus räumliche, demografische und Verhaltensdaten. Zur Charakterisierung der sozialen Organisation von M. decemlineata analysierte ich die Zusammensetzung sozialer Einheiten im Hinblick auf Geschlecht und Alter der Individuen und ihre Streifgebietsgröße und –verteilung. Außerdem analysierte ich das Geschlechterverhältnis, Mortalität und Reproduktionsmerkmale der Population. Des weiteren analysierte ich mitochondriale DNA und Mikrosatelliten der 63 beprobten sowie 33 weiterer Individuen aus einer vorherigen Studie zwischen 2000 und 2010. Die Mikrosatelliten-Analyse basierte auf 13 Loci der Fossa (Cryptoprocta ferox), die in vorläufigen Tests erfolgreich amplifizierten. Um die lokale genetische Struktur und Abwanderungsmuster aufzudecken, analysierte ich die Haplotypendiversität von Männchen und Weibchen. Basierend auf der Mikrosatellitenanalyse untersuchte ich Verwandtschaft innerhalb der Geschlechter und sozialer Einheiten sowie Elternschaften und Geschwisterverhältnisse. Männchen und Weibchen lebten in kleinen gleichgeschlechtlichen sozialen Einheiten. Insgesamt beobachtete ich neun weibliche Einheiten und 13 Assoziationen von Männchen in 497 h, sammelte 10,411 Verhaltensscans und 1,879 Triangulationspunkte. Weibliche Einheiten basierten auf Matrilinien. Ihre Mitglieder waren enger verwandt als unter Zufallsbedingungen erwartet und umfassten durchschnittlich zwei adulte Weibchen, ein Juveniles und ein Junges. Weibliche Einheiten behaupteten eigene Territorien. Ihre Streifgebietsgröße (90% Kernel, arithmetisches Mittel: 30.4 ha) stand nicht in Zusammenhang mit der Zahl ihrer Mitglieder, war aber größer während der kargen Trockenzeit als zur Regenzeit. Männchen bildeten Assoziationen von bis zu vier Individuen, die sich während der Paarungszeit auflösten und in ihrer Zusammensetzung zwischen Jahren variierten. In der großen Mehrheit waren assoziierte Männchen nicht näher miteinander verwandt als durch Zufall erwartet. Die Streifgebiete der einzelnen Männchen (90% Kernel, arithmetisches Mittel: 63.9 ha) überlappten stark mit solchen von mit ihnen assoziierten und nicht-assoziierten Männchen und mit denen von bis zu 4 weiblichen Einheiten. Es wanderten mehr Männchen als Weibchen ab, bestätigt durch höhere Haplotypendiversität bei Männchen als bei Weibchen. Die Lebenslaufstrategien waren überwiegend langsam, wobei Männchen in jüngerem Alter abwanderten als Weibchen. Die Mortalitätsraten unterschieden sich nicht signifikant zwischen den Geschlechtern. Beobachtungen lassen jedoch darauf schließen, dass besonders allein umherstreifende Männchen anfällig gegen Prädation waren. Der Fortpflanzungserfolg der Weibchen, gemessen an der Zahl der lebend erschienenen Jungen zeigte keine signifikante Ungleichverteilung, aber Post-partum-Mortalität beschränkte die erfolgreiche Fortpflanzung auf dominante Tiere. Die Verteilung der Vaterschaften, das Geschlechterverhältnis der Adulten zugunsten der Männchen und das Paarungsverhalten deuteten auf gemäßigte Promiskuität hin, wobei einige Männchen Junge in verschiedenen weiblichen Einheiten innerhalb derselben Paarungssaison zeugten. Schlussfolgernd lässt sich sagen, dass die Muster der Verteilung von Männchen und Weibchen in M. decemlineata wichtigen Vorhersagen sozio-ökologischer Theorie folgten. Vorteile bei der Vermeidung von Fressfeinden bestimmten die Vergesellschaftung von Individuen in beiden Geschlechtern. Verwandtschaft war hingegen keine bestimmende Determinante der Sozialität unter Männchen. Die sexuelle Segregation in M. decemlineata schien stark mit Fortpflanzungsstrategien zusammenzuhängen, die sich im Umherstreifen der Männchen, daraus resultierender Aktivitätsunterschiede und in sexueller Belästigung der Weibchen durch die Männchen und darauf folgender Aggression der Weibchen ausdrückten. Bei Weibchen resultierte gelegentliche Abwanderung wahrscheinlich aus der Kosten-Nutzen-Abwägung zwischen philopatrischem Gruppenleben und der Möglichkeit der eigenen Fortpflanzung in unbesetzten Territorien. In vergleichender Perspektive zeigt die Sozialität von M. decemlineata ein höheres Niveau als es für mehrere Arten der Klade der ‚solitären Herpestiden‘ beschrieben wurde. Allgemeine Muster des Paarungssystems deuten jedoch auf einen vergleichsweise ursprünglichen Zustand innerhalb der Säugetierevolution hin. Die Merkmale der Sozialstruktur und des Paarungssystems bieten Ansatzpunkte für weitere Forschung und Vergleiche mit den Herpestiden, z. B. im Hinblick auf die Intensität und Mechanismen weiblicher Konkurrenz und Determinanten des Fortpflanzungserfolgs sowie einer möglichen Rolle der Partnerwahl.

<p>The principle objective of this investigation was to develop an understanding of the physiological response and ecological aspects of winter torpor of small carnivores, specifically striped skunks (<i>Mephitis mephitis</i>) in the northern environment. An experiment was undertaken to investigate the physiological response of skunks to solitary and communal over-winter strategies. Solitary skunks were able to undergo daily torpor to conserve energy to survive the winter, whereas communal skunks were able to use social huddling to reduce energy expenditure and rarely entered torpor. Due to seasonal changes in life requirements, den selection criteria change throughout the year. I examined the landscape metrics and habitat characteristics surrounding dens to evaluate the hierarchical selection and use of dens during winter (i.e., for torpor) and summer (i.e., for parturition). Den structures commonly used for winter dens were buildings, whereas den structures used for maternity dens were rockpiles and underground burrows. Habitat surrounding den sites influenced den use; animals chose den sites closer to roads, water sources, habitat edges, and crop fields. Seasonal movements of skunks from winter dens to the following summer home ranges were examined with respect to winter grouping (i.e., solitary or communal) and winter den structure (i.e., underground burrow or building) to investigate factors that influence spatial distribution of skunks. Male and female skunks moved similar distances (~1.5 km) from winter dens to the center of home ranges established in summer, irrespective of winter grouping status and winter den structure use. Due to limited movement in spring, skunks from communal winter dens had higher spatial overlap of summer home ranges than did skunks from solitary dens, producing spatial aggregation of skunk activities surrounding winter communal den sites. Consequently, winter communal dens represent localized hotspots in the landscape. The effects of extrinsic variables (i.e., environment and diseases) and intrinsic characteristics (i.e., age, gender, and body condition) on cumulative winter survival rate were examined. Winter survival rates were driven mostly by winter condition (i.e., low ambient temperature and snow depth), rabies, and body condition. These results suggest that winter severity probably poses a limit on the northern distribution of the species.</p>

<p>The principle objective of this investigation was to develop an understanding of the physiological response and ecological aspects of winter torpor of small carnivores, specifically striped skunks (<i>Mephitis mephitis</i>) in the northern environment. An experiment was undertaken to investigate the physiological response of skunks to solitary and communal over-winter strategies. Solitary skunks were able to undergo daily torpor to conserve energy to survive the winter, whereas communal skunks were able to use social huddling to reduce energy expenditure and rarely entered torpor. Due to seasonal changes in life requirements, den selection criteria change throughout the year. I examined the landscape metrics and habitat characteristics surrounding dens to evaluate the hierarchical selection and use of dens during winter (i.e., for torpor) and summer (i.e., for parturition). Den structures commonly used for winter dens were buildings, whereas den structures used for maternity dens were rockpiles and underground burrows. Habitat surrounding den sites influenced den use; animals chose den sites closer to roads, water sources, habitat edges, and crop fields. Seasonal movements of skunks from winter dens to the following summer home ranges were examined with respect to winter grouping (i.e., solitary or communal) and winter den structure (i.e., underground burrow or building) to investigate factors that influence spatial distribution of skunks. Male and female skunks moved similar distances (~1.5 km) from winter dens to the center of home ranges established in summer, irrespective of winter grouping status and winter den structure use. Due to limited movement in spring, skunks from communal winter dens had higher spatial overlap of summer home ranges than did skunks from solitary dens, producing spatial aggregation of skunk activities surrounding winter communal den sites. Consequently, winter communal dens represent localized hotspots in the landscape. The effects of extrinsic variables (i.e., environment and diseases) and intrinsic characteristics (i.e., age, gender, and body condition) on cumulative winter survival rate were examined. Winter survival rates were driven mostly by winter condition (i.e., low ambient temperature and snow depth), rabies, and body condition. These results suggest that winter severity probably poses a limit on the northern distribution of the species.</p>

No description available.

Aphanomyces invadans is the pathogen that causes epizootic ulcerative syndrome (EUS), an economically devastating fish disease in southern Asia. The present thesis considered possible improvements to current methods of monitoring EUS, and examined the mechanisms of the host immune response to A. invadans in order to establish whether they could be enhanced to reduce the impact of EUS on aquaculture. Monoclonal antibody (MAb) technology was considered as a possible improvement to the histopathological methods currently used in diagnosis of EUS. Five MAbs were raised to day-old A. invadans germlings. Four gave weak reactions to A. invadans and cross-reacted with other Aphanomyces spp, though they may be useful for future studies on A. invadans. The other, designated MAb 3gJC9, only cross-reacted with the crayfish plague pathogen, A. astaci, and was used for the development of an immunohistochemistry protocol that may be of use in diagnosis. Immunohistochemistry with MAb 3gJC9, which recognised an extracellular product (ECP) of A. invadans, was specific to A. invadans in fish tissue, although it also recognised A. astaci in plague-infected crayfish. It also recognised the mycelium in fish infected with ulcerative mycosis, indicating that ulcerative mycosis is synonymous with EUS. Preliminary observations indicated that both ECPs and what appeared to be a hitherto unreported early stage of the mycelium are important in the pathology of EUS. Studies in vitro on the macrophages of EUS-susceptible giant gourami Osphronemus gouramy and silver barb Barbodes gonionotus, and EUS-resistant Nile tilapia Oreochromis niloticus, found that their macrophages were able to inhibit the growth of A. invadans. The macrophages of striped snakehead Channa striata did not inhibit A. invadans, which may account for their high EUS-susceptibility, especially as A. invadans strongly inhibited the respiratory burst of snakehead macrophages. Studies on humoral immune responses revealed that complement inhibited A. invadans in the case of snakeheads, gourami and barbs but not tilapia or swamp eels Monopterus albus. The humoral responses of the latter were very different to the four other species, and not elucidated. Low levels of anti A. invadans antibodies were found in tilapia and gourami from an EUS-endemic region, and high levels in snakehead. Snakehead antibodies appeared to be able to inhibit A. invadans even when complement was removed, but lower levels were produced at the low temperatures typically associated with EUS. A range of potential immunostimulants were screened for the ability to enhance resistance to EUS. The two successful products were administered as feed supplements to snakeheads and barbs that were subsequently injected intramuscularly with A. invadans. One, the algal extract Ergosan, showed some beneficial effects on snakeheads although the challenge was inconclusive. The other, the vitamin supplement Salar-bec, accelerated the cellular immune response and reduced mortality in snakeheads and barbs, and enhanced antibody production in snakeheads. The antibody response of snakeheads was further studied by comparing the anti- A. invadans antibody level, inhibitory activity of sera in vitro and protective capacity of sera from EUS-naïve snakeheads to that of snakeheads recently exposed to EUS and those subject to long term EUS-exposure. Sera of populations recently exposed to EUS showed an increased level of antibodies, but little improvement in inhibitory or protective activity. Sera from snakeheads that had endured long term exposure showed a wide range of antibody levels, but marked increases in inhibitory and protective activity. Antibodies cross-reacted with non-pathogenic Aphanomyces spp. in all cases.

<p>Controlling the surface chemistry of 2D materials is critical for the development of next generation applications including nanoelectronics and organic photovoltaics (OPVs). Further, next generation nanoelectronics devices require very specific 2D patterns of conductors and insulators with prescribed connectivity and repeating patterns less than 10 nm. However, both top-down and bottom-up approaches currently used lack the ability to pattern materials with sub 10-nm precision over large scales. Nevertheless, a class of monolayer chemistry offers a way to solve this problem through controlled long-range ordering with superior sub-10 nm patterning resolution. Graphene is most often functionalized noncovalently, which preserves most of its intrinsic properties (<i>i.e.,</i> electronic conductivity) and allows spatial modulation of the surface. Phospholipids such as 1,2-bis(10,12-tricsadiynoyl)-<i>sn­</i>-glycero-3-phosphoethanolamine (diyne PE) form lying down lamellar phases on graphene where both the hydrophilic head and hydrophobic tail are exposed to the interface and resemble a repeating cross section of the cell membrane. Phospholipid is made up of a complex headgroup structure and strong headgroup dipole which allows for a diverse range of chemistry and docking of objects to occur at the nonpolar membrane, these principals are equally as important at the nonpolar interface of 2D materials. A key component in the development of nanoelectronics is the integration of inorganic nanocrystals such as nanowires into materials at the wafer scale. Nanocrystals can be integrated into materials through templated growth on to surface of interest as well as through assembly processes (i.e. interfacial adsorption). </p> <p>In this work, I have demonstrated that gold nanowires (AuNWs) can be templated on striped phospholipid monolayers, which have an orientable headgroup dipoles that can order and straighten flexible 2-nm diameter AuNWs with wire lengths of ~1 µm. While AuNWs in solution experience bundling effects due to depletion attraction interactions, wires adsorb to the surface in a well separated fashion with wire-wire distances (e.g. 14 or 21 nm) matching multiples of the PE template pitch. This suggests repulsive interactions between wires upon interaction with dipole arrays on the surface. Although the reaction and templating of AuNWs is completed in a nonpolar environment (cyclohexane), the ordering of wires varies based on the hydration of the PE template in the presence of excess oleylamine, which forms hemicylindrical micelles around the hydrated headgroups protecting the polar environment. Results suggest that PE template experience membrane-mimetic dipole orientation behaviors, which in turn influences the orientation and ordering of objects in a nonpolar environment.</p> <p>Another promising material for bottom-up device applications is MoS₂substrates due to their useful electronic properties. However, being able to control the surface chemistry of different materials, like MoS₂, is relatively understudied, resulting in very limited examples of MoS₂substrates used in bottom-up approaches for nanoelectronics devices. Diyne PE templates adsorb on to MoS₂­in an edge-on conformation in which the alkyl tails stack on top of each other increasing the overall stability of the monolayer. A decrease in lateral spacing results in high local concentrations of orientable headgroups dipoles along with stacked tails which could affect the interactions and adsorption of inorganic materials (i.e. AuNW) at the interface. </p> <p>Here, I show that both diyne PE/HOPG and diyne PE/MoS₂ substrates can template AuNW of various lengths with long range ordering over areas up to 100 µm². Wires on both substrates experience repulsive interactions upon contact with the headgroup dipole arrays resulting in wire-wire distances greater than the template pitch (7 nm). As the wire length is shortened the measured distance between wires become smaller eventually resulting in tight packed ribbon phases. Wires within these ribbon phases have wire-wire distances equal to the template. Ribbon phases occur on diyne PE/HOPG substrates when the wire length is ~50 nm, whereas wire below ~600 nm produce ribbon phases on diyne PE/MoS_2­substrates. </p> <p>Another important aspect to future scientific development is the catalysis of organic reactions, specifically oxygenation of organic sulfides. Sulfide oxygenation is important for applications such as medicinal chemistry, petroleum desulfurization, and nerve agent detoxification. Both reaction rates and the use of inexpensive oxidants and catalysts are important for practical applications. Hydrogen peroxide and <i>tert</i>-butyl hydroperoxide are ideal oxidants due to being cost efficient and environmentally friendly. Hydrogen peroxide can be activated through transition metal base homogeneous catalysts. Some of the most common catalysts are homo- and hetero-polyoxometalates (POMs) due their chemical robustness. Heptamolybdate [Mo₇O₂₄]^6-is a member of the isopolymolybdate family and its ammonium salt is commercially available and low in cost.²² Heteropolyoxometalates have been widely studied as a catalyst for oxygenation reactions whereas heptamolybdate has been rarely studied in oxygenation reactions. </p> <p> Here I report sulfide oxygenation activity of both heptamolybdate and its peroxo derivate [Mo₇O₂₂(O₂)₂]^6-. Sulfide oxygenation of methyl phenyl sulfide (MPS) by H₂O₂to sulfoxide and sulfone occurs rapidly with 100 % utility of H₂O₂ in the presence of [Mo₇O₂₂(O₂)₂]^6-, suggesting the peroxo adduct is an efficient catalyst. However, heptamolybdate is a faster catalyst compared to [Mo₇O₂₂(O₂)₂]^6- for MPS oxygenation and all other sulfides tested under identical conditions. Pseudo-first order <i>k</i>_cat constants from initial rate kinetics show that [Mo₇O₂₄]^6-catalyzes sulfide oxygenation faster. The significant difference in the <i>k</i>_cat suggests differences in the active catalytic species, which was characterized by both UV-Vis and electrospray ionization mass spectrometry. ESI-MS suggest that the active intermediate of [Mo₇O₂₄]^6-under catalytic reaction conditions for sulfide oxygenation by H₂O₂ is [Mo₂O₁₁]^2-. These results show that heptamolybdate is a highly efficient catalyst for H₂O₂oxygenation of organic sulfides.</p>

This study examines the significance of reading aloud for work with values in school through an analysis of Pojken i randig pyjamas (The Boy in the Striped Pyjamas). The analysis considers the themes and narrative technique of the texts. In this study, reading aloud is viewed as an opportunity for the teacher to read aloud to pupils from a work of literature. The book Pojken i randig pyjamas was selected for study because it is a book that is often chosen for reading aloud and it can lead to many discussions in the classroom. The results show that this book is suitable in many ways for reading aloud in the classroom. The study also finds that this book functions well as a basis for work with values. Although the book deals with the Holocaust, a topic that can be difficult for teachers and pupils to deal with in a good way, the study shows that this book, when the reading is followed by a discussion, can contribute to a broader understanding of both the Holocaust and the outlook on humanity.

<p>The pi-striped, <em>d</em>-wave superconducting (SC) state, which is a type of pair density wave wherein the SC order is spatially modulated, has recently been shown to generate the key ingredients for quantum oscillations consistent with experimental observations (Zelli <em>et al.</em>, 2011, 2012). This was accomplished with a phenomenological approach using non-self-consistent Bogoliubov-de Gennes (BdG) theory. The objective of this thesis is to explore two aspects of this approach: the addition of a charge density wave (CDW) order to the previous non-self-consistent calculations, and an attempt at stabilizing the pi-striped state in fully self-consistent BdG theory. It was found that the CDW order had a minimal effect on the Fermi surface characteristics of the pi-striped state, but that a sufficiently strong CDW degrades the Landau levels which are essential for the formation of quantum oscillations. The self-consistent mean-field calculations were unable to stabilize the pi-striped state under a range of modifications to the Hamiltonian. Free energy calculations with the modulated SC order treated as a parameter demonstrate that the pi-striped state is always less energetically favourable than the normal state for the scenarios which were considered. The results of this study constitute a basis for future, more comprehensive studies, using the BdG approach, of the stability of possible pi-striped SC phases.</p> / Master of Science (MSc)