To see if the vasopressinergic system, implicated in maternal behavior, changes during parenthood in different directions in males and females, I examined the pattern of vasopressin immunoreactivity in prairie voles in which both mother and father care for young and meadow voles in which only the mother cares for young. For both species, I compared the densities of vasopressin immunoreactive (AVP-ir) fibers in males and females that were either sexually naive or in parental state. In both species, AVP-ir fiber densities in the lateral septum (LS), and the lateral habenular nucleus (LHN) were higher in males than in females regardless of their parental state. AVP-ir fiber density in the LS and the LHN was reduced in parental prairie-vole males, while no differences were found in females. The AVP-ir in the LS of parental meadow-vole males and females did not show changes, while the fiber density in their LHN was increased. To see if AVP immunoreactivity in male prairie voles changes before or after the birth of pups, I compared AVP-ir fiber density among males and females that were either housed separately or housed together until after mating (3-P), during early gestation (13-P) or late gestation (21-P), or after the birth of pups (26-P). Under all these conditions, AVP-ir fibers in the LS and the LHN were much denser in males than in females. In males, the lowest density of AVP-ir in the LS and the LHN was found in 3-P males. An intermediate density was found in 13-P and 26-P males. An equally high density was found in sexually naive (0-M) and in 21-P males. In females, no changes in AVP immunoreactivity were found. The decrease in AVP-ir fibers of 3-P males occurred only in presence of a female. Changes in AVP immunoreactivity of male prairie voles could be related either to sexual activity which takes place after the first 3 days of cohabitation and again around pups' birth, behavioral changes associated with pair bonding, or induction of paternal behavior.

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No description available.

The Longnose Lancetfish, Alepisaurus ferox, is a pelagic marine fish that has a heterodont dentition, including large fangs on both the upper and lower jaws. Their diet is well documented and includes salps, hyperiid amphipods, pelagic polychaete worms, mesopelagic fishes, and cephalopods. However, the function of the heterodont dentition, the structure of the teeth, and replacement mode is largely unknown. We studied a series of A. ferox to describe their dentition and tooth replacement. All teeth are replaced extraosseously. Palatine and dentary fangs develop horizontally in the oral epithelium on the lingual surface of dentigerous bones. Developing fangs rotate into place and attach to the bone through a pedicel that forms at the base of each tooth on the lingual side of the dentigerous bone. We compare extraosseous horizontal tooth replacement and rotation of large fangs in A. ferox to examples of other teleosts rotation of fangs. Atlantic Cutlassfish, Trichiurus lepturus, have large, barbed premaxillary and dentary fangs and sharp, dagger-shaped teeth in their oral jaws. We used dry skeletons, histology, SEM, and micro-CT scanning to study T. lepturus to describe its dentition and tooth replacement. We identified and described three modes of intraosseous tooth replacement in T. lepturus depending on the location of the tooth in the jaw. Such distinct modes of tooth replacement in a teleostean species are unknown. We compared modes of replacement in T. lepturus to 20 species of scombroids to explore the phylogenetic distribution of these three replacement modes. Our study highlights the complexity and variability of intraosseous tooth replacement and that developmentally different tooth replacement processes can yield remarkably similar dentitions. We review literature on the comparative anatomy of Ocean Sunfishes (Molidae) and presents new findings based on our studies. We document similarities and differences among the three living genera, Ranzania, Masturus, and Mola using an organ system approach to examine: general body form and external anatomy; skeleton; integument; brain and sense organs; digestive organs; heart and circulation; respiratory system; excretory system; and endocrine organs. Molids have many anatomical specializations such as the formation of the clavus from dorsal- and anal-fin elements, enlarged gills with unusual skeletal supports, a heart with thick walls and more valves than other teleosts, ontogenetic loss of the swimbladder, enlarged kidneys and a well-developed urinary bladder, reduced otoliths, and a spinal cord contained completely within the braincase. Tagging studies on locomotion and diving behavior demonstrate that molids move efficiently over horizontal and vertical distances in the water column, and this new information helps to interpret the many unusual features of molid anatomy.

Objectives: The purpose of the study was to compare a geometric morphometric approach for grouping different skeletal malocclusions to a traditional cephalometric approach for a subject population undergoing orthognathic surgery for treatment of malocclusion. Methods: Traditional cephalometric measurements were used to diagnose the skeletal malocclusion each subject in both the sagittal (SNA, SNB, ANB, Facial Angle) and vertical dimensions (SN-MP, FMA, Downs Y-Axis, Facial Axis, P-A Face Height). These were compared to skeletal diagnoses given by the treating surgeon. Lastly, geometric morphometrics was used to identify shape variance within the population, cluster homogeneous subsets, and identify variance between the clusters. Results: Traditional cephalometric analysis identified 21 Class II open, 18 Class II normal, 5 Class II deep, 3 Class I open, 4 Class I normal, 2 Class I deep, 2 Class III open, 4 Class III normal, 3 Class III deep. The surgeon identified 17 Class II open, 20 Class II normal, 13 Class II deep, 1 Class I open, 0 Class I normal, 0 Class I deep, 4 Class III open, 3 Class III normal, 4 Class III deep. Geometric morphometrics identified 6 clusters showing greatest variance through 1) vertical divergence, 2) sagittal positioning of the jaws, and 3) ramus height. Conclusion: Cephalometric analysis and a geometric morphometrics approaches to classification of malocclusion grouped subjects into distinct populations. However, the groupings did not agree between the two approaches. / Oral Biology

<p> Measurements were taken on 1511 flutes from various localities in Eastern North America. Over 85% of the flutes recorded are from the Cloridorme Formation (Ordovician) of North-Eastern Quebec. Flutes occur in a variety of shapes, on A, B and C beds of the Bouma sequence, but no one shape is confined to any one bed type. However, A beds do tend to have a larger proportion of wide flutes on their soles than B or C beds. Whilst flutes on B and C beds are often found associated with brushes, grooves and signs of organic activity, those on A beds are rarely found associated with any other sole marks. </p> <p> Several parameters of width, length and depth have been measured, but the maximum length of the flute was shown to be an inconsistently measurable parameter. by means of an operator error experiment. The maximum -depth of the flute is found to be independent both of the bed type on which it occurs and also the maximum grain size of that bed. No relationship is found between the total bed thickness and the maximum grain size of the bed. </p> <p> As flutes become broader, the point of maximum depth is found to migrate downstream so that wider flutes have their point of maximum depth quite far back from the nose. </p> <p> Factor analysis shows that two factors control the overall morphology of the flutes: firstly the shape of the nose portion, in planview termed the 'nose angle': and secondly, the ratio of the maximum depth and the distance of this point from the nose. </p> <p> Calculations based on previous experimental work, but using field measurements, suggest that velocities in the order of 7 metres/sec and 4 metres/sec are required for the continuance of flutes on B and C beds respectively. </p> / Thesis / Master of Science (MSc)

A multitude of human tissues, such as bones, tendons, or muscles, are characterized by a hierarchical and highly ordered structure. In many cases, the loss of these tissues requires reconstruction using biocompatible replacement materials. In the field of bone replacement, the pore structure of the material has a crucial influence. Anisotropic porosity would have the advantage of facilitating the ingrowth of cells and newly formed blood vessels as well as the transport of nutrients. In this thesis, scaffolds with a highly ordered and anisotropic pore structure were fabricated using unidirectional freezing. Systematic investigations were carried out on biopolymer solutions (alginate and chitosan) to gain a deeper understanding of the freeze-structuring process. The knowledge gained was then applied to the development of anisotropically structured bone substitute materials. Here, the previously existing material platform for anisotropically structured calcium phosphates was extended to low-temperature phases such as calcium deficient hydroxyapatite (CDHA) or the secondary phosphates monetite and brushite. After the implantation of a biomaterial, the inevitably triggered initial immune response plays a key role in the success of a graft, with immune cells such as neutrophils or macrophages being of particular importance. In this thesis, the influence of anisotropically structured alpha-TCP and CDHA scaffolds as well as their unstructured references on human monocytes/macrophages was investigated. Macrophages produced extracellular traps (ETs) due to mineral nanoparticles formed by the binding of phosphate and calcium ions to human platelet lysate. In particular, incubation of alpha-TCP samples in lysate containing cell culture medium resulted in pronounced particle formation and enhanced release of ETs. / Eine Vielzahl menschlicher Gewebe, wie beispielsweise Knochen, Sehnen oder Muskeln, ist durch eine hierarchische und zum Teil hochgradig geordnete Struktur gekennzeichnet. Der beispielsweise durch Unfälle oder Krankheiten bedingte Verlust dieser Gewebe erfordert in vielen Fällen eine Rekonstruktion mit biokompatiblen Ersatzmaterialien. Neben der chemischen Zusammensetzung spielt deren Architektur eine wichtige Rolle für die Geweberegeneration und schließlich den Heilungserfolg des Implantats. Auch im Bereich des Knochenersatzes hat die Porenstruktur des Materials hierauf einen zentralen Einfluss, wobei der Einsatz von Materialien mit anisotroper Porosität neben der strukturellen Nachahmung des Gewebes den Vorteil hätte, dass das Einwachsen von Zellen und neu gebildeten Blutgefäßen sowie der Nährstofftransport erleichtert würden. In der vorliegenden Doktorarbeit wurden anisotrop poröse Scaffolds mit einer hochgradig geordneten Porenstruktur mit Hilfe der Gefrierstrukturierung hergestellt. Hierfür wurde eine in früheren Arbeiten entwickelte Anlage verwendet, um einen definierten Temperaturgradienten in der Probe zur gerichteten Erstarrung zu erzeugen. Der Kern des Systems besteht aus zwei übereinander angeordneten Peltier-Elemente (PEs), zwischen denen sich die Probenlösung befindet. Durch die Variation der PE-Temperaturen kann das Eiskristallwachstum und schließlich die Porenstruktur innerhalb des Biomaterials gezielt beeinflusst und an die Anforderungen einer gewünschten Anwendung angepasst werden. Das Ziel dieser Arbeit war, ein tieferes Verständnis des Gefrierstrukturierungsprozesses zu erlangen und die gewonnenen Erkenntnisse auf die Entwicklung anisotrop poröser Knochenersatzmaterialien zu übertragen. Hierfür wurden in Kapitel 3 zunächst systematische Untersuchungen an Biopolymerlösungen (Alginat und Chitosan) durchgeführt. Dabei konnte gezeigt werden, dass neben dem äußeren Temperaturgradienten auch die Temperaturen der PEs, die Kühlrate sowie Materialeigenschaften wie das Molekulargewicht, die Konzentration und die Viskosität der Lösung die Porenstruktur beeinflussen. Die Temperatur des Gesamtsystems bestimmte sowohl die Kühlrate als auch die Porendurchmesser, so dass höhere Kühlraten zu kleineren Poren führten. Die Porenorientierung konnte hingegen durch den externen Temperaturgradienten beeinflusst werden, wobei die Poren mit steigendem Gradienten zunehmend senkrecht zur Probenoberfläche orientiert ausgerichtet waren. Bestimmte Parameterkonstellationen, wie beispielsweise eine Temperatur der unteren Kühlfläche unterhalb von 60 °C kombiniert mit einer geringen Temperatur des oberen PE sowie eine hohe Viskosität (über 5 Pas nahe 0 °C) der Vorlösung führten allerdings dazu, dass die Porenausrichtung nicht mehr kontrollierbar war. Auf Basis von Kapitel 4 konnte die bis dato für anisotrop strukturierte Calciumphosphate existierende Materialplattform auf Niedrigtemperaturphasen wie calciumarmen Hydroxylapatit (CDHA) oder die sekundären Phosphate Monetit und Bruschit erweitert werden. Hierfür wurde gesintertes oder ungesintertes -Tricalciumphosphat (-TCP) mit anisotroper Porenstruktur durch hydrothermale Behandlung oder Inkubation in Phosphorsäure in die oben genannten Phasen umgewandelt. Durch die hydrothermale Behandlung konnte sowohl bei ungesinterten als auch bei gesinterten -TCP-Proben eine Phasenumwandlung in CDHA erzielt werden. Die Inkubation in Phosphorsäure führte zu einer Umwandlung in Monetit und Bruschit. Durch die hydrothermale Behandlung für 72 h bei 175 °C erhöhte sich die Porosität der ungesinterten Proben geringfügig von 85 % auf 88 %, während bei den gesinterten Proben ein Anstieg von 75 % auf 88 % zu beobachten war. Darüber hinaus ging eine Phasenumwandlung in CDHA durch die Bildung von feinen Kristallnadeln und -plättchen mit einer Vergrößerung der spezifischen Oberfläche einher. Hinsichtlich der mechanischen Eigenschaften war besonders bemerkenswert, dass die Druckfestigkeit der ungesinterten Proben durch die Phasenumwandlung in Monetit signifikant von (0.76  0.11) auf (5.29  0.94) MPa erhöht wurde. In Kapitel 5 wurde der Einfluss von anisotrop porösen -TCP und CDHA Scaffolds sowie unstrukturierten und aus den gleichen Calciumphosphatphasen bestehenden Referenzproben auf humane Monozyten/Makrophagen untersucht. Nach der Implantation eines Biomaterials spielt die unweigerlich ausgelöste erste Immunreaktion eine Schlüsselrolle für den Erfolg eines Transplantats, wobei Immunzellen wie Neutrophile oder Makrophagen eine entscheidende Rolle spielen. Makrophagen können zur Immobilisierung und zum Abtöten von Mikroorganismen extrazelluläre Fasern (ETs) produzieren. Während in früheren Arbeiten nachgewiesen werden konnte, dass Neutrophile als Reaktion auf Biomaterialien ETs produzieren können, wurde dieser Mechanismus für Makrophagen erstmals in der vorliegenden Doktorarbeit gezeigt. Die ET-Freisetzung wurde von mineralischen Nanopartikeln ausgelöst, welche durch die Bindung von Phosphat- und Calciumionen an menschliches Thrombozytenlysat gebildet wurden. Insbesondere die Inkubation von  TCP Proben in lysathaltigem Zellkulturmedium führte zu einer ausgeprägten Partikelformierung und schließlich zu einer verstärkten Bildung von ETs. Dies ging mit einer erhöhten Freisetzung von pro-inflammatorischen Zytokinen im Vergleich zu CDHA einher. An diese Arbeit anschließende Experimente könnten beispielsweise die Wiederholung von systematischen Studien, wie sie in Kapitel 3 für Biopolymere vorgestellt wurden, mit synthetischen Polymeren wie Polyvinylalkohol (PVA) umfassen. PVA ist ein für den Einsatz als Kryoprotektor vielversprechendes Material, dessen Verwendung für die Kryokonservierung von biologischen Materialien zwingend notwendig ist. Darüber hinaus wäre die Durchführung von in vivo Experimenten erforderlich, um die starke Freisetzung von ETs durch Makrophagen als Reaktion auf strukturierte -TCP Scaffolds sowie die geringere Expression auf CDHA Scaffolds eingehender zu analysieren.

The family Xystodesmidae (Polydesmida) includes 521 species with a center of diversity concentrated in the Appalachian Mountains. Within this family, the genus Cherokia, a monotypic taxon with the type species Cherokia georgiana, is divided into three subspecies. The last revision of this genus was made by Richard Hoffman in 1960. Here, I used morphological and molecular data sets to review the genus, and evaluate whether it is a monophyletic group. I included material from literature records and three natural history collections. Newly collected samples were obtained through a citizen science project. Morphological characters such as the shape of the paranota, body size, and coloration were evaluated. Seven gene loci were used to estimate a molecular phylogeny of the genus, and a species delimitation analysis was used to evaluate the status of the subspecies. The geographical range of Cherokia was expanded to include a newly reported state (Virginia) and ca. 160 new localities compared to the previously known range. Morphological characters such as the shape of the paranota and body size that were historically used to establish subspecies, showed a direct relation with geographical distribution and elevation (clinal variation), but not with the phylogeny. Coloration was variable and did not accord with geography or phylogeny. The phylogeny recovered a monophyletic lineage, and the species delimitation test supports a single species. The molecular and morphological evidence showed that Cherokia is a monotypic genus with the sole species Cherokia georgiana being geographically widespread and highly variable in its morphology / Master of Science in Life Sciences / Millipedes are a mega-diverse group of soil dwelling animals that feed on leaf litter. The Appalachian Mountains has a huge diversity of millipedes, in particular those in the family Xystodesmidae. Within this family, I studied the genus Cherokia, commonly known as "Georgia flat-backed millipedes". The single species in this group, Cherokia georgiana, is divided into three subspecies. The last thorough study of this genus was done by Richard Hoffman in 1960, so a modern analysis with DNA sequencing was needed to test subspecies boundaries. Here, I used hundreds of specimens from three natural history museums, and fresh specimens obtained for DNA sequencing with the help of citizen scientists. I measured the shape and size of the body and coloration patterns to determine if they were related to the geographical distribution of Cherokia. I used DNA sequencing to make an evolutionary tree of the genus. I found Cherokia individuals in Virginia for the first time and found ca. 160 new sites or locations not reported previously. The shape and size of the body was related to millipede location and elevation. Coloration was not related to geography or phylogeny, and in some localities, multiple color patterns co-existed. The genetic information from DNA sequencing indicated that all Cherokia were more closely related to each other than to any other millipede genus. In conclusion, I found that the genus Cherokia is a single species, Cherokia georgiana, that has a wide geographical distribution and a considerable diversity of body shape and color. Diversity of shape and color does not reflect subspecies boundaries but instead reflects intra-population and geographic variation.

Pollen dimorphism has been intensively studied in many species of Angiosperms but not in the Onagraceae. Some species of Oenothera have been reported to present differences in the sizes and starch contents of their pollen grains but most of the research done in the ultrastructure of pollen an microsporogenesis has been performed in species that do not present any pollen polymorphism. In both O. picensis and O. villaricae, each haploid set of chromosomes is united into a ring called a Renner complex. These Renner complexes are each transmitted intact from one generation to the next and, since Oenothera picensis and Oenothera villaricae form fully fertile hybrids when crossed in either direction, it is possible to construct several different combinations of Renner complexes and cytoplasmic backgrounds. In this work, I show the existence of pollen polymorphism in Oenothera picensis, Oenothera villaricae and their hybrids, report on the origin of the polymorphism during microsporogenesis and provide evidence that the different pollen sizes are representing two different genome. I present the hypothesis and evidence that this polymorphism is a morphological and physiological expression of the different genetic characteristics of the pollen grains. Finally, I will indicate how these differences may be related to the phenomenon of non-random fertilization associated with these species of Oenothera.