Development of a regeneration protocol for high frequency somatic embbryogenesis from explants of grapevines (Vitis spp.)

An efficient regeneration protocol was developed for leaf explants derived from in vitro plantlets of grapevine cv. Seyval blanc. High frequency somatic embryo induction could be obtained on a modified NN69 medium with 20 µM NOA in combination with the synthetic cytokinin TDZ (4 µM). The application of 2.5 mM phenylalanine promoted embryo induction dramatically by reducing the induction period, and by increasing the regeneration rate. Embryos could be induced on almost 80 % of the plated leaf discs, and the regeneration capacity could be maintained for at least two years. Explants of Vitis thunbergii and the interspecific hybrid Chancellor could now be regenerated by the application of the regeneration system elaborated for Seyval blanc

Investigations on asymptotic safety of metric, tetrad and Einstein-Cartan gravity

Among the different approaches for a construction of a fundamental quantum theory of gravity the Asymptotic Safety scenario conjectures that quantum gravity can be defined within the framework of conventional quantum field theory, but only non-perturbatively. In this case its high energy behavior is controlled by a non-Gaussian fixed point of the renormalization group flow, such that its infinite cutoff limit can be taken in a well defined way. A theory of this kind is referred to as non-perturbatively renormalizable. In the last decade a considerable amount of evidence has been collected that in four dimensional metric gravity such a fixed point, suitable for the Asymptotic Safety construction, indeed exists. This thesis extends the Asymptotic Safety program of quantum gravity by three independent studies that differ in the fundamental field variables the investigated quantum theory is based on, but all exhibit a gauge group of equivalent semi-direct product structure. It allows for the first time for a direct comparison of three asymptotically safe theories of gravity constructed from different field variables. The first study investigates metric gravity coupled to SU(N) Yang-Mills theory. In particular the gravitational effects to the running of the gauge coupling are analyzed and its implications for QED and the Standard Model are discussed. The second analysis amounts to the first investigation on an asymptotically safe theory of gravity in a pure tetrad formulation. Its renormalization group flow is compared to the corresponding approximation of the metric theory and the influence of its enlarged gauge group on the UV behavior of the theory is analyzed. The third study explores Asymptotic Safety of gravity in the Einstein-Cartan setting. Here, besides the tetrad, the spin connection is considered a second fundamental field. The larger number of independent field components and the enlarged gauge group render any RG analysis of this system much more difficult than the analog metric analysis. In order to reduce the complexity of this task a novel functional renormalization group equation is proposed, that allows for an evaluation of the flow in a purely algebraic manner. As a first example of its suitability it is applied to a three dimensional truncation of the form of the Holst action, with the Newton constant, the cosmological constant and the Immirzi parameter as its running couplings. A detailed comparison of the resulting renormalization group flow to a previous study of the same system demonstrates the reliability of the new equation and suggests its use for future studies of extended truncations in this framework.Unter den verschiedenen Zugängen zur Konstruktion einer fundamentalen Quantentheorie der Gravitation beruht das Prinzip der Asymptotischen Sicherheit auf der Annahme, dass die Quantengravitation im Rahmen einer üblichen Quantenfeldtheorie formuliert werden kann, die allerdings nicht-perturbativ konstruiert werden muss. In diesem Fall wird das Hochenergieverhalten der Theorie durch einen nicht-Gaußchen Fixpunkt des Renormierungsgruppenflusses kontrolliert, so dass der Limes eines unendlichen Cutoffs wohldefiniert ist. Eine solche Theorie wird als nicht-perturbativ renormierbar bezeichnet. Im letzten Jahrzehnt wurden zahlreiche Hinweise gefunden, dass in vierdimensionaler, metrischer Gravitation ein solcher, für die Konstruktion einer asymptotisch sicheren Theorie geeigneter Fixpunkt in der Tat existiert. Die vorliegende Arbeit erweitert das Programm der Asymptotischen Sicherheit um drei voneinander unabhängige Studien, die sich im Feldgehalt der untersuchten Quantentheorien unterscheiden, aber in der durch ein semi-direktes Produkt gegebenen Struktur der zugrundeliegenden Eichgruppe gleichen. Die Arbeit erlaubt damit zum ersten Mal den direkten Vergleich von drei asymptotisch sicheren Theorien der Gravitation, die auf unterschiedlichen fundamentalen Feldern beruhen. Die erste Studie untersucht dabei das gekoppelte System von metrischer Gravitation und SU(N) Yang-Mills Theorie. Insbesondere wird dabei der Einfluss der Gravitation auf das Laufen der Yang-Mills Kopplungskonstante analysiert und dessen Folgen für QED und das Standardmodell diskutiert. In der zweiten Untersuchung wird zum ersten Mal eine asymptotisch sichere Theorie der Gravitation betrachtet, die allein durch das Vielbein beschrieben wird. Ihr Renormierungsgruppenfluss wird mit der entsprechenden Approximation der metrischen Theorie verglichen und der Einfluss der vergrößerten Eichgruppe analysiert. Die dritte Studie untersucht die Asymptotische Sicherheit der Gravitation im Einstein-Cartan Zugang. Dabei dient der Spinzusammenhang neben dem Vielbein als zweite fundamentale Feldvariable. Aufgrund der höheren Anzahl unabhängiger Feldkomponenten und der größeren Eichgruppe ist jede Renormierungsgruppenanalyse dieses Systems ungleich schwieriger als die analoge Rechnung im metrischen Zugang. Um die technische Komplexität der Aufgabe zu verringern wird in dieser Arbeit eine neuartige funktionale Renormierungsgruppengleichung eingeführt, die die Auswertung des Flusses auf ein rein algebraisches Problem reduziert. Um ein erstes Beispiel ihrer Eignung zu geben, wird die neue Gleichung auf eine dreidimensionale Trunkierung von Form der Holst Wirkung angewendet, die die Newton-Konstante, die kosmologische Konstante und den Immirzi-Parameter als laufende Kopplungen enthält. In einem detaillierten Vergleich mit einer früheren Studie desselben Systems wird dabei die Zuverlässigkeit der neuen Gleichung demonstriert, die sie für künftige Untersuchungen von allgemeineren Trunkierungen qualifiziert.262 S

Interethnic analyses of blood pressure loci in populations of East Asian and European descent

Blood pressure (BP) is a major risk factor for cardiovascular disease and more than 200 genetic loci associated with BP are known. Here, we perform a multi-stage genome-wide association study for BP ( max N = 289,038) principally in East Asians and meta-analysis in East Asians and Europeans. We report 19 new genetic loci and ancestry-specific BP variants, conforming to a common ancestry-specific variant association model. At 10 unique loci, distinct non-rare ancestry-specific variants colocalize within the same linkage disequilibrium block despite the significantly discordant effects for the proxy shared variants between the ethnic groups. The genome-wide transethnic correlation of causal-variant effect-sizes is 0.898 and 0.851 for systolic and diastolic BP, respectively. Some of the ancestry-specific association signals are also influenced by a selective sweep. Our results provide new evidence for the role of common ancestry-specific variants and natural selection in ethnic differences in complex traits such as BP.</p

Bringing Telemedicine Initiatives into Regular Care: Theoretical Underpinning for User-Centred Design Processes

Telemedicine is said to change the way care is delivered. Nevertheless, it still faces barriers to overcome the pilot stage and reach a majority of patients in regular care. Missing consideration of user-centred design processes is one major reason for this development as individuals are a key component for the technology’s success. Therefore, we aim to provide recommendations for a user-centred design process, which is, in turn, crucial to successfully implementing telemedicine innovations. To reach this aim, we identified individual-related barriers for telemedicine with an umbrella review. Furthermore, we related the barriers to the Unified Theory of Acceptance and Use of Technology (UTAUT2) proposed by Venkatesh and colleagues. A theoretical explanation helps to generate a broader understanding of what prevents individual acceptance of telemedicine innovations. The provided recommendations are supposed to support researchers and practitioners planning future telemedicine solutions

Stomatal behaviour, photosynthesis and photorespiration of in vitro-grown grapevines: Effects of light and CO2

To improve photosynthesis and growth of grapevines cultivated in vitro (Seyval blanc and SO 4) effects of light intensity, spectral irradiance and CO2 concentration on stomatal behaviour, CO2 fixation and photorespiration were studied. Stomata were shown to respond to changes of light intensity but, unlike photosynthesis, their reactions were delayed and stomatal closure was incomplete in the dark. In contrast, alterations of the CO2 concentration in the headspace (50-2200 ppm) did not cause stomatal reactions. Photosynthesis vs, light intensity relationships indicated lower light compensation points, higher quantum yield and higher rates of light-saturated photosynthesis with ''Fluora'' lamps (maximal spectral irradiance al 460 and 680 nm) compared to ''projector'' lamps (maximal spectral irradiance at 620 nm). Photosynthesis vs. intercellular CO2 concentration relationships indicated varietal differences, the carboxylation efficiency and rates of photosynthesis at CO2 saturation being distinctly higher in the more vigorous variety SO 4 compared to Seyval blanc. Under the usual light conditions of our in vitro culture (50-60 µmol quanta · m-2 s-1, Fluora) the headspace CO2 concentration ranged from 145 to 155 ppm while at the end of a 10-hour dark period it increased to values &gt;3000 ppm. Rates of photorespiration were high (&gt;50 % of photosynthesis) due to the relative low CO2 concentrations and, presumably, due to elevated O2 concentrations in the headspace. It is concluded that the often observed low rates of photosynthesis of in vitro plantlets are mainly due to low light intensity and CO2 concentration in the headspace, the latter depending on the low rates of gas diffusion between ambient air and headspace

Establishment of embryo suspension cultures of grapevines (Vitis L.)

Somatic embryos of Seyval blanc, Dornfelder, Re- gent, Riesling, Müller-Thurgau and Rupestris du Lot originating from leaf discs or anther culture were checked with regard to their ability to be cultivated in suspensions for an induction of secondary embryo- genesis. Culture parameters like carbohydrates, phytohormones, pH, intervals of media change, the anti-oxidant dithioerythritol (DTE), and the size of embryos were tested to optimize the suspension cul- ture conditions. In liquid culture, glucose was better utilized than sucrose or maltose. The pH (5.8 - 5.0) and the embryo size mainly influenced the quality of em- bryogenic suspensions. Medium change proved to be necessary at a pH &lt;4.5 or after a culture period &gt;4 weeks. Browning of media was avoided by addition of 3 or 6 mM DTE. Homogeneous suspension cultures were maintained by fragmentation of embryos accord- ing to their developmental stage. From suspensions containing embryos of globulary- and heart-stage (0.5-2.0 mm) 50 % new somatic embryos were ob- tained whereas further developed embryos (torpedo- stage, &gt;2.0 mm) were not suitable for cultivation in suspension. Best induction of secondary embryos was obtained from Seyval blanc, Dornfelder, Müller-Thurgau and Rupestris du Lot. After transfer to a LS- medium the seedlings of Dornfelder and Müller-Thurgau regenerated to rooted in vitro plantlets