Molecular differentiation and development of species specific primers for horse cestodes species Anoplocephala perfoliata and Paranoplocephala mamillana

Deckblatt-Impressum persönlicher Dank Inhaltsverzeichnis Abkürzungsverzeichnis Einleitung Literaturübersicht Material und Methoden Ergebnisse Diskussion Zusammenfassung Summary Literaturverzeichnis Anhang Danksagung SelbständigkeitserklärungGegenstand und Ziel der vorliegenden Arbeit bestanden darin, die am häufigsten in Europa vorkommenden Bandwurmarten des Pferdes Anoplocephala perfoliata und Paranoplocephala mamillana mit Hilfe der PCR zu differenzieren und neue spezifische Primer für diese zu entwickeln. Ausgehend von Proglottiden der beiden Bandwurm-Spezies wurde mit den plathelminthenspezifischen Cytochrom-C Oxidase I Primern (COI-Primer) ein Abschnitt der mitochondrialen DNA amplifiziert. Nach Sequenzierung wurden aus den jeweiligen Amplifikaten beider Spezies diskriminierende Primer konstruiert. Für die am häufigsten vorkommenden Bandwurmarten des Pferdes konnten spezies-spezifische Primer synthetisiert werden (AP-Primer und PM-Primer). Diese erlangten in den durchgeführten Versuchen eine analytische Spezifität von 100 %. Mit einer Verdünnungsreihe wurde die analytische Sensitivität beider Primerpaare bestimmt. Sie ergab für den Anoplocephala perfoliata-Primer (AP 72L/341R) eine Nachweisgrenze von ca. 12,5 pg DNA und für den Paranoplocephala mamillana- Primer (PM 26L/346R) eine Nachweisgrenze von ca.1,65 pg DNA. Durch den Einsatz von AP- und PM-Primern war es nur einmalig möglich, Bandwurm DNA in experimentell infizierten Pferdekotproben nachzuweisen. Die hierbei aufgetretenen Probleme wurden in der vorliegenden Arbeit diskutiert. Weiterführende Untersuchungen sind geplant.Objective and intention of this thesis were the differentiation of Europes most widely spread horse cestodes species Anoplocephala perfoliata and Paranoplocephala mamillana by means of PCR and the development of new primers. Based on proglottides of both cestodes species, a sequence of the mitochondrial DNA was amplified by platyhelminthes specific cytochrome c oxidase subunit I primer (COI primer). After sequencing, discriminate primers were constructed based on the amplifications of both species. For the most frequent horse cestodes species, species specific primers could be synthesised (AP-primer and PM-primer). In the tests run in this study, these primers attained an analytic specificity of 100 %. By means of continuing dilution, the analytical sensitivity of both primer-pairs were determined. The Anoplocephala perfoliata-Primer (AP 72L/341R) showed a detection sensitivity of approximately 12,5 pg DNA and for the Paranoplocephala mamillana-Primer (PM 26L/346R) a detection sensitivity of approximately 1,65 pg DNA was determined. The use of AP-primer and PM-primer allowed to furnish proof of cestodes-DNA in faecal samples from experimental infected horses just once. The problems associated with our tests are discussed in this thesis. Further tests are intended

Non-stationary data-driven computational portfolio theory and algorithms

The aim of the dissertation is the development of a data-driven portfolio optimization framework beyond standard assumptions. Investment decisions are either based on the opinion of a human expert, who evaluates information about companies, or on statistical models. The most famous methods based on statistics are the Markowitz portfolio model and utility maximization. All statistical methods assume certain knowledge over the underlying distribution of the returns, either by imposing Gaussianity, by expecting complete knowledge of the distribution or by inferring sufficiently good estimators of parameters. Yet in practice, all methods suffer from incomplete knowledge, small sample sizes and the problem that parameters might be varying over time. A new, model-free approach to the portfolio optimization problem allowing for time-varying dynamics in the price processes is presented. The methods proposed in this work are designed to solve the problem with less a-priori assumptions than standard methods, like assumptions on the distribution of the price processes or assumptions on time-invariant statistical properties. The new approach introduces two new parameters and a method to chose these based on principles of information theory. An analysis of different approaches to incorporate additional information is performed before a straightforward approach to the out-of-sample application is introduced. The structure of the numerical problem is obtained directly from the problem of portfolio optimization, resulting in a system of objective function and constraints known from non-stationary time series analysis. The incorporation of transaction costs allows to naturally obtain regularization that is normally included for numerical reasons. The applicability and the numerical feasibility of the method are demonstrated in a low-dimensional example in-sample and in a high-dimensional example in- and out-of-sample in an environment with mixed transaction costs. The performance of both examples is measured and compared to standard methods, as the Markowitz approach and to methods based on techniques to analyse non- stationary data, like Hidden Markov Models

Near-tropical subsurface ice on Mars

Near-surface perennial water ice on Mars has been previously inferred down to latitudes of about 45{\deg} and could result from either water vapor diffusion through the regolith under current conditions or previous ice ages precipitations. In this paper we show that at latitudes as low as 25{\deg} in the southern hemisphere buried water ice in the shallow (< 1 m) subsurface is required to explain the observed surface distribution of seasonal CO2 frost on pole facing slopes. This result shows that possible remnants of the last ice age, as well as water that will be needed for the future exploration of Mars, are accessible significantly closer to the equator than previously thought, where mild conditions for both robotic and human exploration lie

Stratigraphy and evolution of the buried CO2 deposit in the Martian south polar cap

Observations by the Shallow Radar instrument on Mars Reconnaissance Orbiter reveal several deposits of buried CO2 ice within the south polar layered deposits. Here we present mapping that demonstrates this unit is 18% larger than previously estimated, containing enough mass to double the atmospheric pressure on Mars if sublimated. We find three distinct subunits of CO2 ice, each capped by a thin (10-60 m) bounding layer (BL). Multiple lines of evidence suggest that each BL is dominated by water ice. We model the history of CO2 accumulation at the poles based on obliquity and insolation variability during the last 1 Myr assuming a total mass budget consisting of the current atmosphere and the sequestered ice. Our model predicts that CO2 ice has accumulated over large areas several times during that period, in agreement with the radar findings of multiple periods of accumulation.6 month embargo; first published: 25 April 2016This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Pattern formation in active model C with anchoring: bands, aster networks, and foams

We study the dynamics of pattern formation in a minimal model for active mixtures made of microtubules and molecular motors. We monitor the evolution of the (conserved) microtubule density and of the (non-conserved) nematic order parameter, focusing on the effects of an "anchoring" term that provides a direct coupling between the preferred microtubule direction and their density gradient. The key control parameter is the ratio between activity and elasticity. When elasticity dominates, the interplay between activity and anchoring leads to formation of banded structures that can undergo additional bending or rotational instabilities. When activity dominates, the nature of anchoring instead gives rise to a range of active cellular solids, including aster-like networks, disordered foams and spindle-like patterns. We speculate that the introduced "active model C" with anchoring is a minimal model to describe pattern formation in a biomimetic analogue of the microtubule cytoskeleton

SHARAD radar sounding of the Vastitas Borealis Formation in Amazonis Planitia

Amazonis Planitia has undergone alternating episodes of sedimentary and volcanic infilling, forming an interleaved sequence with an upper surface that is very smooth at the kilometer scale. Earlier work interprets the near-surface materials as either young, rough lava flows or ice-rich sediment layers, overlying a basement comprising the Vastitas Borealis Formation and earlier Hesperian plains. Sounding radar profiles across Amazonis Planitia from the Shallow Radar (SHARAD) instrument on the Mars Reconnaissance Orbiter reveal a subsurface dielectric interface that increases in depth toward the north along most orbital tracks. The maximum depth of detection is 100–170 m, depending upon the real dielectric permittivity of the materials, but the interface may persist at greater depth to the north if the reflected energy is attenuated below the SHARAD noise floor. The dielectric horizon likely marks the boundary between sedimentary material of the Vastitas Borealis Formation and underlying Hesperian volcanic plains. The SHARAD-detected interface follows the surface topography across at least one of the large wrinkle ridges in north central Amazonis Planitia. This conformality suggests that Vastitas Borealis sediments, at least in this region, were emplaced prior to compressional tectonic deformation. The change in radar echo strength with time delay is consistent with a loss tangent of 0.005–0.012 for the column of material between the surface and the reflector. These values are consistent with dry, moderate-density sediments or the lower end of the range of values measured for basalts. While a component of distributed ice in a higher-loss matrix cannot be ruled out, we do not find evidence for a dielectric horizon within the Vastitas Borealis Formation that might suggest an abrupt change from an upper dry layer to an ice-rich lower deposit

Science results from sixteen years of MRO SHARAD operations

In operation for &gt;16 years to date, the Mars Reconnaissance Orbiter (MRO) Shallow Radar (SHARAD) sounder has acquired data at its nominal 300–450 m along-track and 3-km cross-track resolution covering &gt;55% of the Martian surface, with nearly 100% overlap in coverage at that scale in the polar regions and in a number of smaller mid-latitude areas. While SHARAD data have opened a new window into understanding the interior structures and properties of Martian ices, volcanics, and sedimentary deposits up to a few kilometers in depth, they have also led to new revelations about the deeper interior and the behavior of the planet’s ionosphere. Here we summarize the data collected by SHARAD over this time period, the methods used in the analysis of that data, and the resulting scientific findings. The polar data are especially rich, revealing complex structures that comprise up to several dozen reflecting interfaces that extend to depths of 3 km, which inform the evolution of Martian climate in the late Amazonian period. SHARAD observations of mid-latitude lobate debris aprons and other glacier-like landforms detect strong basal reflections and low dielectric loss, confirming that they are icerich debris-covered glaciers. In other mid-latitude terrains, SHARAD data demonstrate the presence of widespread ground ices, likely at lower concentrations. SHARAD signals also probe non-icy materials, mapping out stacked lava flows, probing low-density materials thought to be ash-fall deposits, and occasionally penetrating sedimentary deposits, all of which reveal the structures and interior properties diagnostic of emplacement processes. SHARAD signals are impacted by their passage through the Martian ionosphere, revealing variations in time and space of the total electron content linked with the remanent magnetic field. Advanced techniques developed over the course of the mission, which include subband and super-resolution processing, coherent and incoherent summing, and three-dimensional (3D) radar imaging, are enabling new discoveries and extending the utility of the data. For 3D imaging, a cross-track spacing at the nominal 3-km resolution is more than sufficient to achieve good results, but finer spacing of 0.5 km or less significantly improves the spatially interpolated radar images. Recent electromagnetic modeling and a flight test show that SHARAD’s signal-to-noise ratio can be greatly improved with a large (~120◦) roll of the spacecraft to reduce interference with the spacecraft body. Both MRO and SHARAD are in remarkably fine working order, and the teams look forward to many more years in which to pursue improvements in coverage density, temporal variability in the ionosphere, and data quality that promise exciting new discoveries at Mars