Analysis of parameters to challenge fundamental principles in viticulture

Mestrado Vinifera EuroMaster - Instituto Superior de AgronomiaThree different pruning methods were used as a model system to challenge fundamental principles in viticulture. Different viticultural and physiological parameters of field grown Chardonnay, Sauvignon blanc, Chenin blanc and Syrah have been quantified, analysed and compared; main focus was on the comparison of ratios between and amongst vegetative and reproductive parameters. Changes in grapevine morphology due to the pruning system as already described in literature could be proofed; number of buds left at winter-pruning is “correlated” with the number of shoots, leaves and bunches formed during the next year. Shoot length, internode length, leaf size and bunch mass are correlated inversely to the number of remaining winter buds. Source:sink relationship has been affected by pruning method due to changes in size and priority of the source and sink organs, which also affected carbon allocation as well as plant biomass development. Impacts on the rachis development have been found, impacting on the % share of berries on a bunch and the ratio rachis length to rachis mass. Alternative pruned vines seemed to have more sanitary problems and appeared not to be adapted for high quality grape production. Almost no parameter or ratio was stable when changing pruning system; indicating the difficulty of imposing absolute numbers and use them as a recipe for decision making in viticultur

Textverständlichkeit und kognitive Belastung beim Lernen mit Text und Hypertext

Ziel der Studie ist es, Aufschlüsse über die Auswirkungen des "Cognitive Overhead" auf den Lernerfolg in universitären Lernsituationen zu erhalten. Beim Lernen mit Hypertexten wird häufig die kognitive Mehrbelastung durch die Planung des eigenen Informationszugriffs, den so genannten "Cognitive Overhead", angeführt: Durch die im Vergleich zu einem linearen Text zusätzlich erforderliche Aufmerksamkeitszuwendung für Navigationsanforderungen soll sich die Verarbeitungskapazität für den Lernprozess verringern. Allerdings könnte ein Hypertext auch zu einem aktiveren Lese- und damit Lernverhalten ermuntern. Insbesondere bei komplexeren Inhalten, bei denen der Erwerb eines vertieften Verständnisses notwendig ist, könnte sich die Nicht-Linearität des Mediums als lernförderlich erweisen. In einem 2x2-Untersuchungsdesign wurden Textlinearität ("Hypertext" versus "linearer Bildschirmtext") und Textverständlichkeit (ein Maß der Komplexität der Lernsituation) variiert. Insgesamt 44 Personen im Alter zwischen 20 und 41 Jahren nahmen an der Studie teil. Erwartet wurde ein Wechselwirkungseffekt: bei komplexeren Aufgaben sollten Hypertexte besser geeignet sein, bei einfacheren Aufgaben hingegen lineare Texte. Die Ergebnisse konnten den erwarteten Wechselwirkungseffekt nicht bestätigen. Allerdings lernten die Probanden in der Hypertextbedingung gleich gut und in einigen Teilaufgaben signifikant besser als die mit dem linearen Text Lernenden: ein negativer Effekt des "Cognitive Overhead" konnte also nicht gefunden werden. Die Komplexität der verwendeten Lernaufgabe scheint eine zentrale Rolle beim Lernen mit Text und Hypertext zu spielen und wird in diesem Kontext diskutiert. (DIPF/Orig.)The term cognitive overhead is used to describe the additional mental effort necessary for navigation through hypertext. It is often seen as an endemic problem of learning with hypertext, as supposedly the cognitive overhead leads to less well processing of the learning material. On the other hand it could be argued that hypertext with its non-linear nature may lead to more active reading and studying. This may be particularly helpful for studying more complex knowledge areas. A 2x2 experimental study was conducted to research the impact of text format (hypertext vs. linear text) and readability (as a measure of complexity) on the learning outcome. An interaction effect was hypothesized: the linear text should be superior for studying the less complex text, while the hypertext should be superior studying the more complex text. The results do not confirm the hypothesis. However, they show no negative impact of the cognitive overhead at all. The discussion explaining the results focuses on the complexity of the used learning task. (DIPF/Orig.

Pressepolitik in der NS-Zeit - Eine gruppenbiographische Analyse der RedakteurInnen der 1943 eingestellten Tageszeitung "Neuigkeits-Welt-Blatt"

Diese Diplomarbeit beschäftigt sich mit den Biographien der JournalistInnen der 1943 eingestellten Tageszeitung “Neuigkeits-Welt-Blatt” (NWB). Das NWB war in der Zeit des Austrofaschismus offizielles Regierungsblatt und gegen die Nationalsozialistische Bewegung. Mit dem Einmarsch der Nationalsozialisten änderte sich jedoch auch die Blattlinie zu Gunsten der neuen Machthaber. Die Lebensläufe der für die Zeitung tätigen JournalistInnen sollen illustrieren wie diese “Wendehalsigkeit” des Mediums von der Mehrzahl der dahinter stehenden Menschen offensichtlich ohne große Bedenken mitgetragen wurde, doch auch das Schicksal eines jüdischen Journalisten und die Auswirkungen der Nazi-Herrschaft auf sein Leben findet in diese Arbeit Eingang und ergänzt diese somit auch um die Sicht der Opfer der Nationalsozialisten. Vor dem theoretischen Hintergrund der historischen Kommunikationsforschung und der Methode der biographischen Forschung, sowie den (medien-)geschichtlichen Entwicklungen soll das Leben und Schaffen der JournalistInnen des NWB dargestellt werden. Die Interpretation der Forschungsfragen ergab, dass die Mehrzahl der JournalistInnen die Ideologie des Regimes vertraten oder sich aus Karrieregründen zumindest mit dieser arrangierten. Die Ausnahme stellt hier die Biographie des jüdischen Journalisten Adalbert Felsenburg dar, dessen Karriere und Leben durch die Nazis zerstört wurde. Aus der Untersuchung der Lebenswege nach 1945 ergab, dass die Mehrheit der unter dem NS-Regime für das NWB tätigen JournalistInnen, ebenso wie dessen Herausgeber, ihre Karriere trotz Entnazifizierungsmaßnahmen meist weiter führten. Die Arbeit wird mit der Feststellung geschlossen, dass weitere biographische Forschung gerade im Hinblick auf diese Kontinuitäten sehr wichtig wäre

Impact of the growth support on the transcellular transport of nanoparticles

Bei biopharmazeutischen Fragestellungen stellen Transportstudien mit Zellmonolayern bereits seit einigen Jahren eine wichtige Standardtechnik dar, die eine in vitro Bestimmung der Permeabilität von Arzneistoffen oder Prodrugs ermöglicht. Neben der Beurteilung der Transportcharakteristik können solche Untersuchungen auch Aufschluss über Cytoadhäsions- und Internalisationsprozesse moderner Arzneistoff-Trägersysteme, wie Mikro- oder Nanopartikel, geben. Für derartige Transportuntersuchungen werden die Zellen auf speziellen Filtermembranen angezüchtet. Um den Einflusses dieser Wachstumsunterlage auf den Transport von 200 nm fluoreszenzmarkierten Polystyrol-Nanopartikeln durch einen Caco-2 Monolayer zu untersuchen, wurden Filtereinsätze mit unterschiedlicher Porenweite (0.4 µm, 1 µm und 3 µm) eingesetzt. Darüber hinaus wurden die Zellen auch in Einsätzen kultiviert, bei denen ein Edelstahlgitter als Wachstumsoberfläche (Maschenweite 25 µm) diente. Dieses Gitter könnte eine interessante Alternative zu herkömmlichen Filtereinsätzen darstellen. Auf diesen Metallgittern konnte ebenfalls die Ausbildung eines konfluenten Caco-2 Monolayers beobachtet werden, wobei der TEER bei ~ 477 Ω cm² lag. Die Transportexperimente mit Caco-2 Monolayern bei 37°C über einen Zeitraum von 24 h ergaben, dass bei 0.4 µm und 1 µm Porenfiltern kein Partikeltransport festzustellen war. Bei den 3 µm Filtereinsätzen wurde zwar ein von der Porosität der Filter abhängiger Transport detektiert, dieser war aber mit 0.02 % (transparente Filter) bzw 0.04 % (translucente Filter) der ursprünglich eingesetzten Menge äußerst gering. Im Vergleich dazu konnte für die Edelstahlgitter eine deutlich erhöhte Transportrate durch den Caco-2 Layer bestimmt werden, wobei hier im basolateralen Kompartiment 1.2 x 1010 Partikel nachgewiesen werden konnten. Dabei muss festgehalten werden, dass ein indirekter Nachweis des Partikeltransports mittels Fluoreszenzanalyse fehleranfällig ist, da aus den Partikeln freigesetzter Fluoreszenzfarbstoff zu falsch positiven Ergebnissen führen kann. Dies konnte durch Ultrazentrifugationsexperimente bestätigt werden. Zusammenfassend lässt sich festhalten, dass die Transportraten nicht nur, wie erwünscht, durch den Zelllayer beeinflusst werden, sondern auch die Permeabilitätscharakteristik der Wachstumsunterlage eine nicht zu vernachlässigende Rolle spielt. Aufgrund ihrer höheren Porosität könnten hier Edelstahlgitter einen entscheidenden Vorteil bieten, vor allem wenn eine biopharmazeutische Bewertung moderner Arzneistoff-Trägersysteme Ziel der Untersuchungen ist.Transport studies across cell monolayers in vitro are biopharmaceutical standard techniques for determining the permeability of drugs and prodrugs. Moreover, transport systems can be used to investigate cytoadhesion, internalization and transcytosis of novel drug carriers such as nano- and microparticles. To elucidate to which extent the filter membrane used for cell cultivation effects the transport rates, permeability studies across Caco-2 monolayers cultivated on filter membranes with pore sizes of 0.4 µm, 1 µm and 3 µm were performed using 0.2 µm fluorescence labelled polystyrene nanoparticles. In addition, the cells were cultivated on stainless steel grids with a mesh width of 25 µm representing a potential alternative to conventional filter materials. The cell monolayers cultivated on these metal grids were confluent and characterized by a transepithelial electrical resistance of 477 Ω cm2. Subsequent transport studies at 37°C illustrated that within 24 h no nanoparticles reached the basolateral compartment, if the cell layers had been cultivated on filter membranes with 0.4 and 1 µm pore size. In case of membranes with 3 µm pore diameter, particle transport depended on pore density and corresponded to 0.02 % and 0.04 % of the initially added particles in case of transparent and translucent membranes, respectively. In contrast, clearly higher particle concentrations of 1.2 x 1010 were determined in the basolateral compartment when highly porous metal grids had been used as growth support for the Caco-2 layer. Interestingly, indirect detection of nanoparticles by fluorimetry was found to be prone to considerable error. As indicated by ultracentrifugation experiments, false positive results were mainly due to fluorescence marker that had been released from the nanoparticles. The presented results indicate that in addition to the cell layer, permeability characteristics of the filter membrane affect analyte transport. Since they allow to exclusively study transport across the cell layer, highly porous growth materials like the presented metal grid might prove clearly beneficial for biopharmaceutical transport studies

Improving the integrity and the microstructural features of electron beam welds of a creep-resistant martensitic steel by local (de-)alloying

Martensitic 9–12% chromium steels present the most preferred material group for high-temperature components in thermal power plants. Previous investigations revealed that due to the use of a creep-resistant martensitic steel strengthened with boron and nitrogen (MarBN), the minimum creep rate can significantly be decreased. Furthermore, the formation of the fine-grained heat-affected zone (FGHAZ) due to welding can be suppressed. This FGHAZ is subject to the most dominant failure mode (type IV cracking) of welded joints during creep exposure. By using electron beam welding, the total width of the heat-affected zone (HAZ) can be reduced compared to conventional arc welding processes. Preceding investigation on electron beam welding of MarBN steel showed recurring difficulties with hot cracking within the fusion zone. Various approaches were tried to produce defect-free welds without the use of any filler metal, but no satisfactory results were achieved. In this investigation, the chemical composition of the fusion zone was modified by the addition of conventional 9% chromium creep-resistant steel as a filler material. By using the filler material, the fusion zone was locally (de-)alloyed and defect-free joints of MarBN steel were produced.publishersversionpublishe

Combination of Electron Beam Surface Structuring and Plasma Electrolytic Oxidation for Advanced Surface Modification of Ti6Al4V Alloy

The objective of this work is to study for the first time the combination of electron beam (EB) surface structuring and plasma electrolytic oxidation (PEO) with the aim of providing a multiscale topography and bioactive surface to the Ti6Al4V alloy for biomedical applications. Ca and P-containing coatings were produced via 45 s PEO treatments over multi-scale EB surface topographies. The coatings morphology and composition were characterized by a means of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The effect on the previous EB topography was evaluated by means of a 3D optical profilometry and electrochemical response via potentiodynamic polarization tests. In general, the PEO process, morphology, composition and growth rate of the coatings were almost identical, irrespective of the topography treated. Minimal local differences were found in terms of morphology, and the growth rate were related to specific topographical features. Nevertheless, all the PEO-coated substrates presented essentially the same corrosion resistance. Electrochemical tests revealed a localized crevice corrosion susceptibility of all the bare EB topographies, which was successfully prevented after the PEO treatment.Depto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasTRUEMICINN/AEI/ FEDER, UEComunidad de MadridComunidad de MadridUCMChristian Doppler Forschungsgesellschaftpu

Differential Development of Children’s Understanding of the Cardinality of Small Numbers and Zero

Counting and the understanding of cardinality are important steps in children’s numerical development. Recent studies have indicated that language and visuospatial abilities play an important role in the development of children’s cardinal knowledge of small numbers. However, predictors for the knowledge about zero were usually not considered in these studies. Therefore, the present study investigated whether the acquisition of cardinality knowledge on small numbers and the concept of zero share cross-domain and domain-specific numerical predictors. Particular interest was paid to the question whether visuospatial abilities – in addition to language abilities – were associated with children’s understanding of small numbers and zero. Accordingly, we assessed kindergarteners aged 4 to 5 years in terms of their understanding of small numbers and zero as well as their visuospatial, general language, counting, Arabic number identification abilities, and their finger number knowledge. We observed significant zero-order correlations of vocabulary, number identification, finger knowledge, and counting abilities with children’s knowledge about zero as well as understanding of the cardinality of small numbers. Subsequent regression analyses substantiated the influences of counting abilities on knowledge about zero and the influences of both counting abilities and finger knowledge on children’s understanding of the cardinality of small numbers. No significant influences of cross-domain predictors were observed. In sum, these results indicate that domain-specific numerical precursor skills seem to be more important for children’s development of an understanding of the cardinality of small numbers as well as of the concept of zero than the more proximal cross-domain abilities such as language and visuospatial abilities

More than simple facts: : cross-linguistic differences in place-value processing in arithmetic fact retrieval

Linguistic specificities such as the inversion property of number words (e.g., in German 43 is spoken dreiundvierzig, literally three and forty) moderate Arabic number processing. So far, cross-linguistic studies have mostly focused on inversion-related effects on simple (number comparison) and calculation-based (multi-digit addition) magnitude processing of numerical information. Despite the assumption that multiplication facts are represented in verbal format, not much attention has been paid to inversion-related influences on multiplication fact retrieval. Accordingly, the current study evaluated inversion-related effects on the processing of place-value information in multiplication. In a verification paradigm, the decade consistency effect (i.e., more errors when the decade of a solution probe shares the decade digit with the correct solution) was larger for English- than German-speaking participants for table-related probes. Processing of decade digits might be prioritised in English-speaking participants because the decade-digit is named first in English number words whereas in German number words the unit-digit is named first. Our results indicate that i) the influence of specificities of a verbal number word formation on place-value processing generalise to arithmetic fact retrieval and ii) inversion of number words might even be advantageous in specific cases

The relationship between glucose and the liver-alpha cell axis – A systematic review

Until recently, glucagon was considered a mere antagonist to insulin, protecting the body from hypoglycemia. This notion changed with the discovery of the liver-alpha cell axis (LACA) as a feedback loop. The LACA describes how glucagon secretion and pancreatic alpha cell proliferation are stimulated by circulating amino acids. Glucagon in turn leads to an upregulation of amino acid metabolism and ureagenesis in the liver. Several increasingly common diseases (e.g., non-alcoholic fatty liver disease, type 2 diabetes, obesity) disrupt this feedback loop. It is important for clinicians and researchers alike to understand the liver-alpha cell axis and the metabolic sequelae of these diseases. While most of previous studies have focused on fasting concentrations of glucagon and amino acids, there is limited knowledge of their dynamics after glucose administration. The authors of this systematic review applied PRISMA guidelines and conducted PubMed searches to provide results of 8078 articles (screened and if relevant, studied in full). This systematic review aims to provide better insight into the LACA and its mediators (amino acids and glucagon), focusing on the relationship between glucose and the LACA in adult and pediatric subjects

Numbers and language : what's new in the past 25 years?

Numerous studies in psychology, cognitive neuroscience and psycholinguistics have used pictures of objects as stimulus materials. Currently, authors engaged in cross-linguistic work or wishing to run parallel studies at multiple sites where different languages are spoken must rely on rather small sets of black-and-white or colored line drawings. These sets are increasingly experienced as being too limited. Therefore, we constructed a new set of 750 colored pictures of concrete concepts. This set, MultiPic, constitutes a new valuable tool for cognitive scientists investigating language, visual perception, memory and/or attention in monolingual or multilingual populations. Importantly, the MultiPic databank has been normed in six different European languages (British English, Spanish, French, Dutch, Italian and German). All stimuli and norms are freely available at http://www.bcbl.eu/databases/multipi