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This article first outlines different ways of how psycholinguists have dealt with linguistic diversity and illustrates these approaches with three familiar cases from research on language processing, language acquisition, and language disorders. The second part focuses on the role of morphology and morphological variability across languages for psycholinguistic research. The specific phenomena to be examined are to do with stem-formation morphology and inflectional classes; they illustrate how experimental research that is informed by linguistic typology can lead to new insights.
The present study approaches the Spanish postposed constructions creo Ø and creo yo ‘[p], [I] think’ from a cognitive-constructionist perspective. It is argued that both constructions are to be distinguished from one another because creo Ø has a subjective function, while in creo yo, it is the intersubjective dimension that is particularly prominent. The present investigation takes both a qualitative and a quantitative perspective. With regard to the latter, the problem of quantitative representativity is addressed. The discussion posed the question of how empirical research can feed back into theory, more precisely, into the framework of Cognitive Construction Grammar. The data to be analyzed here are retrieved from the corpora Corpus de Referencia del Español Actual and Corpus del Español.
Complex networks are ubiquitous in nature and society. They appear in vastly different domains, for instance as social networks, biological interactions or communication networks. Yet in spite of their different origins, these networks share many structural characteristics. For instance, their degree distribution typically follows a power law. This means that the fraction of vertices of degree k is proportional to k^(−β) for some constant β; making these networks highly inhomogeneous. Furthermore, they also typically have high clustering, meaning that links between two nodes are more likely to appear if they have a neighbor in common.
To mathematically study the behavior of such networks, they are often modeled as random graphs. Many of the popular models like inhomogeneous random graphs or Preferential Attachment excel at producing a power law degree distribution. Clustering, on the other hand, is in these models either not present or artificially enforced.
Hyperbolic random graphs bridge this gap by assuming an underlying geometry to the graph: Each vertex is assigned coordinates in the hyperbolic plane, and two vertices are connected if they are nearby. Clustering then emerges as a natural consequence: Two nodes joined by an edge are close by and therefore have many neighbors in common. On the other hand, the exponential expansion of space in the hyperbolic plane naturally produces a power law degree sequence. Due to the hyperbolic geometry, however, rigorous mathematical treatment of this model can quickly become mathematically challenging.
In this thesis, we improve upon the understanding of hyperbolic random graphs by studying its structural and algorithmical properties. Our main contribution is threefold. First, we analyze the emergence of cliques in this model. We find that whenever the power law exponent β is 2 < β < 3, there exists a clique of polynomial size in n. On the other hand, for β >= 3, the size of the largest clique is logarithmic; which severely contrasts previous models with a constant size clique in this case. We also provide efficient algorithms for finding cliques if the hyperbolic node coordinates are known. Second, we analyze the diameter, i. e., the longest shortest path in the graph. We find
that it is of order O(polylog(n)) if 2 < β < 3 and O(logn) if β > 3. To complement
these findings, we also show that the diameter is of order at least Ω(logn). Third, we provide an algorithm for embedding a real-world graph into the hyperbolic plane using only its graph structure. To ensure good quality of the embedding, we perform extensive computational experiments on generated hyperbolic random graphs. Further, as a proof of concept, we embed the Amazon product recommendation network and observe that products from the same category are mapped close together.
During the last decade, high intensity interval training (HIIT) has been used as an alternative to endurance (END) exercise, since it requires less time to produce similar physiological adaptations. Previous literature has focused on HIIT changes in aerobic metabolism and cardiorespiratory fitness, however, there are currently no studies focusing on its neuromuscular adaptations.
Therefore, this thesis aimed to compare the neuromuscular adaptations of both HIIT and END after a two-week training intervention, by using a novel technology called high-density surface electromyography (HDEMG) motor unit decomposition. This project consisted in two experiments, where healthy young men were recruited (aged between 18 to 35 years). In experiment one, the reliability of HDEMG motor unit variables (mean discharge rate, peak-to-peak amplitude, conduction velocity and discharge rate variability) was tested (Study 1), a new method to track the same motor units longitudinally was proposed (Study 2), and the level of low (<5Hz) and high (>5Hz) frequency motor unit coherence between vastus medialis (VM) and lateralis (VL) knee extensor muscles was measured (Study 4). In experiment two, a two-week HIIT and END intervention was conducted where cardiorespiratory fitness parameters (e.g. peak oxygen uptake) and motor unit variables from the VM and VL muscles were assessed pre and post intervention (Study 3).
The results showed that HDEMG is reliable to monitor changes in motor unit activity and also allows the tracking of the same motor units across different testing sessions. As expected, both HIIT and END improved cardiorespiratory fitness parameters similarly. However, the neuromuscular adaptations of both types of training differed after the intervention, with HIIT showing a significant increase in knee extensor muscle strength that was accompanied by increased VM and VL motor unit discharge rates and HDEMG amplitude at the highest force levels [(50 and 70% of the maximum voluntary contraction force (MVC)], while END training induced a marked increase in time to task failure at lower force levels (30% MVC), without any influence on HDEMG amplitude and discharge rates. Additionally, the results showed that VM and VL muscles share most of their synaptic input since they present a large amount of low and high frequency motor unit coherence, which can explain the findings of the training intervention where both muscles showed similar changes in HDEMG amplitude and discharge rates.
Taken together, the findings of the current thesis show that despite similar improvements in cardiopulmonary fitness, HIIT and END induced opposite adjustments in motor unit behavior. These results suggest that HIIT and END show specific neuromuscular adaptations, possibly related to their differences in exercise load intensity and training volume.
This work reports about new high-resolution imaging and spectroscopic observations of solar type III radio bursts at low radio frequencies in the range from 30 to 80 MHz. Solar type III radio bursts are understood as result of the beam-plasma interaction of electron beams in the corona. The Sun provides a unique opportunity to study these plasma processes of an active star. Its activity appears in eruptive events like flares, coronal mass ejections and radio bursts which are all accompanied by enhanced radio emission. Therefore solar radio emission carries important information about plasma processes associated with the Sun’s activity. Moreover, the Sun’s atmosphere is a unique plasma laboratory with plasma processes under conditions not found in terrestrial laboratories. Because of the Sun’s proximity to Earth, it can be studied in greater detail than any other star but new knowledge about the Sun can be transfer to them. This “solar stellar connection” is important for the understanding of processes on other stars.
The novel radio interferometer LOFAR provides imaging and spectroscopic capabilities to study these processes at low frequencies. Here it was used for solar observations.
LOFAR, the characteristics of its solar data and the processing and analysis of the latter with the Solar Imaging Pipeline and Solar Data Center are described. The Solar Imaging Pipeline is the central software that allows using LOFAR for solar observations. So its development was necessary for the analysis of solar LOFAR data and realized here. Moreover a new density model with heat conduction and Alfvén waves was developed that provides the distance of radio bursts to the Sun from dynamic radio spectra.
Its application to the dynamic spectrum of a type III burst observed on March 16, 2016 by LOFAR shows a nonuniform radial propagation velocity of the radio emission. The analysis of an imaging observation of type III bursts on June 23, 2012 resolves a burst as bright, compact region localized in the corona propagating in radial direction along magnetic field lines with an average velocity of 0.23c. A nonuniform propagation velocity is revealed. A new beam model is presented that explains the nonuniform motion of the radio source as a propagation effect of an electron ensemble with a spread velocity distribution and rules out a monoenergetic electron distribution. The coronal electron number density is derived in the region from 1.5 to 2.5 R☉ and fitted with the newly developed density model. It determines the plasma density for the interplanetary space between Sun and Earth. The values correspond to a 1.25- and 5-fold Newkirk model for harmonic and fundamental emission, respectively. In comparison to data from other radio instruments the LOFAR data shows a high sensitivity and resolution in space, time and frequency.
The new results from LOFAR’s high resolution imaging spectroscopy are consistent with current theories of solar type III radio bursts and demonstrate its capability to track fast moving radio sources in the corona. LOFAR solar data is found to be a valuable source for solar radio physics and opens a new window for studying plasma processes associated with highly energetic electrons in the solar corona.
Proteins are natural polypeptides produced by cells; they can be found in both animals and plants, and possess a variety of functions. One of these functions is to provide structural support to the surrounding cells and tissues. For example, collagen (which is found in skin, cartilage, tendons and bones) and keratin (which is found in hair and nails) are structural proteins. When a tissue is damaged, however, the supporting matrix formed by structural proteins cannot always spontaneously regenerate. Tailor-made synthetic polypeptides can be used to help heal and restore tissue formation.
Synthetic polypeptides are typically synthesized by the so-called ring opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCA). Such synthetic polypeptides are generally non-sequence-controlled and thus less complex than proteins. As such, synthetic polypeptides are rarely as efficient as proteins in their ability to self-assemble and form hierarchical or structural supramolecular assemblies in water, and thus, often require rational designing. In this doctoral work, two types of amino acids, γ-benzyl-L/D-glutamate (BLG / BDG) and allylglycine (AG), were selected to synthesize a series of (co)polypeptides of different compositions and molar masses.
A new and versatile synthetic route to prepare polypeptides was developed, and its mechanism and kinetics were investigated. The polypeptide properties were thoroughly studied and new materials were developed from them. In particular, these polypeptides were able to aggregate (or self-assemble) in solution into microscopic fibres, very similar to those formed by collagen. By doing so, they formed robust physical networks and organogels which could be processed into high water-content, pH-responsive hydrogels. Particles with highly regular and chiral spiral morphologies were also obtained by emulsifying these polypeptides. Such polypeptides and the materials derived from them are, therefore, promising candidates for biomedical applications.
Extreme hydro-meteorological events, such as severe droughts or heavy rainstorms, constitute primary manifestations of climate variability and exert a critical impact on the natural environment and human society. This is particularly true for high-mountain areas, such as the eastern flank of the southern Central Andes of NW Argentina, a region impacted by deep convection processes that form the basis of extreme events, often resulting in floods, a variety of mass movements, and hillslope processes. This region is characterized by pronounced E-W gradients in topography, precipitation, and vegetation cover, spanning low to medium-elevation, humid and densely vegetated areas to high-elevation, arid and sparsely vegetated environments. This strong E-W gradient is mirrored by differences in the efficiency of surface processes, which mobilize and transport large amounts of sediment through the fluvial system, from the steep hillslopes to the intermontane basins and further to the foreland. In a highly sensitive high-mountain environment like this, even small changes in the spatiotemporal distribution, magnitude and rates of extreme events may strongly impact environmental conditions, anthropogenic activity, and the well-being of mountain communities and beyond. However, although the NW Argentine Andes comprise the catchments for the La Plata river that traverses one of the most populated and economically relevant areas of South America, there are only few detailed investigations of climate variability and extreme hydro-meteorological events.
In this thesis, I focus on deciphering the spatiotemporal variability of rainfall and river discharge, with particular emphasis on extreme hydro-meteorological events in the subtropical southern Central Andes of NW Argentina during the past seven decades. I employ various methods to assess and quantify statistically significant trend patterns of rainfall and river discharge, integrating high-quality daily time series from gauging stations (40 rainfall and 8 river discharge stations) with gridded datasets (CPC-uni and TRMM 3B42 V7), for the period between 1940 and 2015. Evidence for a general intensification of the hydrological cycle at intermediate elevations (~ 0.5 – 3 km asl) at the eastern flank of the southern Central Andes is found both from rainfall and river-discharge time-series analysis during the period from 1940 to 2015. This intensification is associated with the increase of the annual total amount of rainfall and the mean annual discharge. However, most pronounced trends are found at high percentiles, i.e. extreme hydro-meteorological events, particularly during the wet season from December to February.An important outcome of my studies is the recognition of a rapid increase in the amount of river discharge during the period between 1971 and 1977, most likely linked to the 1976-77 global climate shift, which is associated with the North Pacific Ocean sea surface temperature variability. Interestingly, after this rapid increase, both rainfall and river discharge decreased at low and intermediate elevations along the eastern flank of the Andes. In contrast, during the same time interval, at high elevations, extensive areas on the arid Puna de Atacama plateau have recorded increasing annual rainfall totals. This has been associated with more intense extreme hydro-meteorological events from 1979 to 2014. This part of the study reveals that low-, intermediate, and high-elevation sectors in the Andes of NW Argentina respond differently to changing climate conditions.
Possible forcing mechanisms of the pronounced hydro-meteorological variability observed in the study area are also investigated. For the period between 1940 and 2015, I analyzed modes of oscillation of river discharge from small to medium drainage basins (102 to 104 km2), located on the eastern flank of the orogen. First, I decomposed the relevant monthly time series using the Hilbert-Huang Transform, which is particularly appropriate for non-stationary time series that result from non-linear natural processes. I observed that in the study region discharge variability can be described by five quasi-periodic oscillatory modes on timescales varying from 1 to ~20 years. Secondly, I tested the link between river-discharge variations and large-scale climate modes of variability, using different climate indices, such as the BEST ENSO (Bivariate El Niño-Southern Oscillation Time-series) index. This analysis reveals that, although most of the variance on the annual timescale is associated with the South American Monsoon System, a relatively large part of river-discharge variability is linked to Pacific Ocean variability (PDO phases) at multi-decadal timescales (~20 years). To a lesser degree, river discharge variability is also linked to the Tropical South Atlantic (TSA) sea surface temperature anomaly at multi-annual timescales (~2-5 years).
Taken together, these findings exemplify the high degree of sensitivity of high-mountain environments with respect to climatic variability and change. This is particularly true for the topographic transitions between the humid, low-moderate elevations and the semi-arid to arid highlands of the southern Central Andes. Even subtle changes in the hydro-meteorological regime of these areas of the mountain belt react with major impacts on erosional hillslope processes and generate mass movements that fundamentally impact the transport capacity of mountain streams. Despite more severe storms in these areas, the fluvial system is characterized by pronounced variability of the stream power on different timescales, leading to cycles of sediment aggradation, the loss of agriculturally used land and severe impacts on infrastructure.
Solar-like stars maintain their magnetic fields thanks to a dynamo mechanism. The Babcock-Leighton dynamo is one possible dynamo that has the particularity to require magnetic flux tubes. Magnetic flux tubes are assumed to form at the bottom of the convective zone and rise buoyantly to the surface. A delayed dynamo model has been suggested, where the delay accounts for the rise time of the magnetic flux tubes; a time, that has been ignored by former studies.
The present thesis aims to study the applicability of the flux tube/Babcock-Leighton dynamo to other stars. To do so, we attempt to constrain the rise time of magnetic flux tubes thanks to the first fully compressible MHD simulations of rising magnetic flux tubes in stratified rotating spherical shells.
Such simulations are limited to an unrealistic parameter space, therefore, a scaling relation is required to scale the results to realistic physical regimes. We extended earlier works on 2D scaling relations and derived a general scaling law valid for both 2D and 3D. We then carried out two large series of numerical experiments and verified that the scaling law we have derived indeed applies to the fully non-linear case. It allowed us to extract a constraint for the rise time of magnetic flux tubes that is valid for any solar-like star. We finally introduced this constraint to a delayed dynamo model.
By carrying out simulations of a mean-field, delayed, flux tube/Babcock-Leighton dynamo, we were able to identify a new dynamo regime resulting from the delay. This regime requires delays about an entire cycle and exhibits subequipartition magnetic activity. Revealing this new regime shows that even for long delays the flux tube/Babcock-Leighton dynamo can still deliver non-decaying solutions and remains a good candidate for a wide range of solar-like stars.
Diese Arbeit befasst sich mit der Herstellung und Charakterisierung von thermoresponsiven Filmen auf Goldelektroden durch Fixierung eines bereits synthetisierten thermoresponsiven Polymers. Als Basis für die Entwicklung der responsiven Grenzfläche dienten drei unterschiedliche Copolymere (Polymere I, II und III) aus der Gruppe der thermisch schaltbaren Poly(oligo(ethylenglykol)methacrylate).
Die turbidimetrischen Messungen der Copolymere in Lösungen haben gezeigt, dass der Trübungspunkt vom pH-Wert, der Gegenwart von Salzen sowie von der Ionenstärke der Lösung abhängig ist. Nach der Charakterisierung der Polymere in Lösung wurden Experimente der kovalenten Kopplung der Polymere I bis III an die Oberfläche der Gold-Elektroden durchgeführt. Während bei Polymeren I und II die Ankopplung auf einer Amidverbrückung basierte, wurde bei Polymer III als alternative Methode zur Immobilisierung eine photoinduzierte Anbindung unter gleichzeitiger Vernetzung gewählt. Der Nachweis der erfolgreichen Ankopplung erfolgte bei allen Polymeren elektrochemisch mittels Cyclovoltammetrie und Impedanzspektroskopie in K3/4[Fe(CN)6]-Lösungen. Wie die Ellipsometrie-Messungen zeigten, waren die erhaltenen Polymer-Filme unterschiedlich dick. Die Ankopplung über Amidverbrückung lieferte dünne Filme (10 – 15 nm), während der photovernetzte Film deutlich dicker war (70-80 nm) und die darunter liegende Oberfläche relativ gut isolierte.
Elektrochemische Temperaturexperimente an Polymer-modifizierten Oberflächen in Lösungen in Gegenwart von K3/4[Fe(CN)6] zeigten, dass auch die immobilisierten Polymere I bis III responsives Temperaturverhalten zeigen. Bei Elektroden mit den immobilisierten Polymeren I und II ist der Temperaturverlauf der Parameterwerte diskontinuierlich – ab einem kritischen Punkt (37 °C für Polymer I und 45 °C für Polymer II) wird zunächst langsame Zunahme der Peakströme wird deutlich schneller. Das Temperaturverhalten von Polymer III ist dagegen bis 50 °C kontinuierlich, der Peakstrom sinkt hier durchgehend.
Weiterhin wurde mit den auf Polymeren II und III basierten Elektroden deren Anwendung als responsive Matrix für Bioerkennungsreaktionen untersucht. Es wurde die Ankopplung von kleinen Biorezeptoren, TAG-Peptiden, an Polymer II- und Polymer III-modifizierten Elektroden durchgeführt. Das hydrophile FLAG-TAG-Peptid verändert das Temperaturverhalten des Polymer II-Films unwesentlich, da es die Hydrophilie des Netzwerkes nicht beeinflusst. Weiterhin wurde der Effekt der Ankopplung der ANTI-FLAG-TAG-Antikörper an FLAG-TAG-modifizierte Polymer II-Filme untersucht. Es konnte gezeigt werden, dass die Antikörper spezifisch an FLAG-TAG-modifiziertes Polymer II binden. Es wurde keine unspezifische Anbindung von ANTI-FLAG-TAG an Polymer II beobachtet. Die Temperaturexperimente haben gezeigt, dass die thermische Restrukturierung des Polymer II-FLAG-TAG-Filmes auch nach der Antikörper-Ankopplung noch stattfindet. Der Einfluss der ANTI-FLAG-TAG-Ankopplung ist gering, da der Unterschied in der Hydrophilie zwischen Polymer II und FLAG-TAG bzw. ANTI-FLAG-TAG zu gering ist.
Für die Untersuchungen mit Polymer III-Elektroden wurde neben dem hydrophilen FLAG-TAG-Peptid das deutlich hydrophobere HA-TAG-Peptid ausgewählt. Wie im Falle der Polymer II Elektrode beeinflusst das gekoppelte FLAG-TAG-Peptid das Temperaturverhalten des Polymer III-Netzwerkes nur geringfügig. Die gemessenen Stromwerte sind geringer als bei der Polymer III-Elektrode. Das Temperaturverhalten der FLAG-TAG-Elektrode ähnelt dem der reinen Polymer III-Elektrode – die Stromwerte sinken kontinuierlich bis die Temperatur von ca. 40 °C erreicht ist, bei der ein Plateau beobachtet wird. Offensichtlich verändert FLAG-TAG auch in diesem Fall nicht wesentlich die Hydrophilie des Polymer III-Netzwerkes. Das an Polymer III-Elektroden gekoppelte hydrophobe HA-TAG-Peptid beeinflusst dagegen im starken Maße den Quellzustand des Netzwerkes. Die Ströme für die HA-TAG-Elektroden sind deutlich geringer als die für die FLAG-TAG-Polymer III-Elektroden, was auf geringeren Wassergehalt und dickeren Film zurückzuführen ist. Bereits ab 30 °C erfolgt der Anstieg von Stromwerten, der bei Polymer III- bzw. bei Polymer III-FLAG-TAG-Elektroden nicht beobachtet werden kann. Das gekoppelte hydrophobe HA-TAG-Peptid verdrängt Wasser aus dem Polymer III-Netzwerk, was in der Stauchung des Films bereits bei Raumtemperatur resultiert. Dies führt dazu, dass der Film im Laufe des Temperaturanstieges kaum noch komprimiert. Die Stromwerte steigen in diesem Fall entsprechend des Anstiegs der temperaturabhängigen Diffusion des Redoxpaares. Diese Untersuchungen zeigen, dass das HA-TAG-Peptid als Ankermolekül deutlich besser für eine potentielle Verwendung der Polymer III-Filme für sensorische Zwecke geeignet ist, da es sich deutlich in der Hydrophilie von Polymer III unterscheidet.
Numerous reports of relatively rapid climate changes over the past century make a clear case of the impact of aerosols and clouds, identified as sources of largest uncertainty in climate projections. Earth’s radiation balance is altered by aerosols depending on their size, morphology and chemical composition. Competing effects in the atmosphere can be further studied by investigating the evolution of aerosol microphysical properties, which are the focus of the present work.
The aerosol size distribution, the refractive index, and the single scattering albedo are commonly used such properties linked to aerosol type, and radiative forcing. Highly advanced lidars (light detection and ranging) have reduced aerosol monitoring and optical profiling into a routine process. Lidar data have been widely used to retrieve the size distribution through the inversion of the so-called Lorenz-Mie model (LMM). This model offers a reasonable treatment for spherically approximated particles, it no longer provides, though, a viable description for other naturally occurring arbitrarily shaped particles, such as dust particles. On the other hand, non-spherical geometries as simple as spheroids reproduce certain optical properties with enhanced accuracy. Motivated by this, we adapt the LMM to accommodate the spheroid-particle approximation introducing the notion of a two-dimensional (2D) shape-size distribution.
Inverting only a few optical data points to retrieve the shape-size distribution is classified as a non-linear ill-posed problem. A brief mathematical analysis is presented which reveals the inherent tendency towards highly oscillatory solutions, explores the available options for a generalized solution through regularization methods and quantifies the ill-posedness. The latter will improve our understanding on the main cause fomenting instability in the produced solution spaces. The new approach facilitates the exploitation of additional lidar data points from depolarization measurements, associated with particle non-sphericity. However, the generalization of LMM vastly increases the complexity of the problem. The underlying theory for the calculation of the involved optical cross sections (T-matrix theory) is computationally so costly, that would limit a retrieval analysis to an unpractical point. Moreover the discretization of the model equation by a 2D collocation method, proposed in this work, involves double integrations which are further time consuming. We overcome these difficulties by using precalculated databases and a sophisticated retrieval software (SphInX: Spheroidal Inversion eXperiments) especially developed for our purposes, capable of performing multiple-dataset inversions and producing a wide range of microphysical retrieval outputs.
Hybrid regularization in conjunction with minimization processes is used as a basis for our algorithms. Synthetic data retrievals are performed simulating various atmospheric scenarios in order to test the efficiency of different regularization methods. The gap in contemporary literature in providing full sets of uncertainties in a wide variety of numerical instances is of major concern here. For this, the most appropriate methods are identified through a thorough analysis on an overall-behavior basis regarding accuracy and stability. The general trend of the initial size distributions is captured in our numerical experiments and the reconstruction quality depends on data error level. Moreover, the need for more or less depolarization points is explored for the first time from the point of view of the microphysical retrieval. Finally, our approach is tested in various measurement cases giving further insight for future algorithm improvements.
Möglichkeiten der Mittelstandsförderung durch Vergaberechtsgestaltung und Vergaberechtspraxis
(2016)
Die Förderungswürdigkeit und die Förderungsfähigkeit mittelständischer Unternehmen ist ein gesamteuropäisches, wirtschaftspolitisches Anliegen. Hiervon zeugen zum einen zahlreiche Regelungen im Primär-, Sekundär-, Verfassungs- und einfachgesetzlichem Recht, zum anderen auch die Bedeutung der mittelständischen Unternehmen im wirtschaftlichen, gesellschaftlichen und sozialen Gefüge. So herrscht innerhalb der Europäischen Union nicht nur der Slogan „Vorfahrt für KMU“, sondern auch die im Frühjahr 2014 verabschiedeten Vergaberichtlinien legten ein besonderes Augenmerk auf die Förderung des Zugangs der KMU zum öffentlichen Beschaffungsmarkt. Denn gemessen am Steuerungs- und Lenkungspotenzial der Auftragsvergabe, deren Einfluss auf die Innovationstätigkeit der Wirtschaft sowie deren Auswirkungen auf die Wirtschafts- und Wettbewerbstätigkeit auf der einen Seite und dem gesamtwirtschaftlichen Stellenwert der mittelständischen Unternehmen auf der anderen Seite, sind mittelständische Unternehmen trotz zahlreicher europäischer und nationaler Initiativen im Vergabeverfahren unterrepräsentiert. Neben der undurchsichtigen Regelungsstruktur des deutschen Vergaberechts, unterliegen die mittelständischen Unternehmen vom Beginn bis zum Ende des Vergabeverfahrens besonderen Schwierigkeiten. Dieser Ausgangsbefund wurde zum Anlass genommen, um die Möglichkeiten der Mittelstandsförderung durch Vergaberechtsgestaltung und Vergaberechtspraxis erneut auf den Prüfstand zu stellen.
Infants' lexical processing is modulated by featural manipulations made to words, suggesting that early lexical representations are sufficiently specified to establish a match with the corresponding label. However, the precise degree of detail in early words requires further investigation due to equivocal findings. We studied this question by assessing children’s sensitivity to the degree of featural manipulation (Chapters 2 and 3), and sensitivity to the featural makeup of homorganic and heterorganic consonant clusters (Chapter 4). Gradient sensitivity on the one hand and sensitivity to homorganicity on the other hand would suggest that lexical processing makes use of sub-phonemic information, which in turn would indicate that early words contain sub-phonemic detail. The studies presented in this thesis assess children’s sensitivity to sub-phonemic detail using minimally demanding online paradigms suitable for infants: single-picture pupillometry and intermodal preferential looking. Such paradigms have the potential to uncover lexical knowledge that may be masked otherwise due to cognitive limitations. The study reported in Chapter 2 obtained a differential response in pupil dilation to the degree of featural manipulation, a result consistent with gradient sensitivity. The study reported in Chapter 3 obtained a differential response in proportion of looking time and pupil dilation to the degree of featural manipulation, a result again consistent with gradient sensitivity. The study reported in Chapter 4 obtained a differential response to the manipulation of homorganic and heterorganic consonant clusters, a result consistent with sensitivity to homorganicity. These results suggest that infants' lexical representations are not only specific, but also detailed to the extent that they contain sub-phonemic information.
Das Widerspenstige bändigen
(2016)
Dem Handeln von Lehrkräften wird in der schulischen Praxis wie in der wissenschaftlichen Literatur ein wesentlicher Einfluss auf die Qualität von schulischem Unterricht zugesprochen. Auch wenn umfangreiche normative Vorstellungen über ein gutes Lehr-Handeln bestehen, so gibt es wenig Erkenntnis darüber, welche Gründe Lehrkräfte für ihr pädagogisches Handeln haben. Das Handeln von Lehrkräften kann nur dann adäquat erfasst werden, wenn Bildung einerseits als Weitergabe von Kultur an die nachfolgende Generation und andererseits als eine vom sich bildenden Subjekt ausgehende Selbst- und Weltverständigung verstanden wird. Damit einhergehende Anforderungen an die Lehrkraft stehen notwendigerweise in Widerspruch zueinander; dies gilt besonders für eine Gesellschaft mit großer kultureller und sozialer Heterogenität. Bei der Suche nach Zusammenhängen zwischen Persönlichkeit, pädagogischem Wissen oder Kompetenzen und einem unterrichtlichen Handeln wird häufig von einer Bedingtheit dieses Handelns ausgegangen und dieses auf kognitive Aspekte und an externen Normen orientierte Merkmale verkürzt. Ertragreicher für eine Antwort auf die Frage nach den Begründungen sind wissenschaftliche Arbeiten, die Professionalität als eine Bezugnahme auf einen besonderen strukturellen Rahmen beschreiben, der durch Widersprüche geprägt ist und Entscheidungen zu den Spannungsfeldern pädagogischer Verhältnisse erfordert. Die subjektwissenschaftliche Lerntheorie bietet eine Basis für ein Verständnis eines Lernens in institutionellen Kontexten ausgehend von den Lerninteressen der Schülerinnen und Schüler. Lehren kann darauf bezugnehmend als Unterstützung von Selbst- und Weltverständigungsprozessen durch Wertschätzung, Verstehen und Angebote alternativer Bedeutungshorizonte verstanden werden. Das Handeln von Lehrkräften ist als sinngebende Bezugnahme auf daraus resultierende sowie institutionelle Anforderungen mittels gesellschaftlicher Bedeutungsstrukturen verstehbar. Das handelnde Subjekt erschließt sich selbst und die Welt mit Hilfe von Bedeutungen. Diese können verstanden werden als der Besonderheit der Biographie, der gesellschaftlichen Position sowie der Lebenslage geschuldete Reinterpretationen gesellschaftlicher Bedeutungsstrukturen. Im empirischen Verfahren können mittels eines Übergangs von sequentiellen zu komparativen Analysen Positionierungen als thematisch spezifische und über die konkrete Handlungssituation hinausreichende Bedeutungs-Begründungs-Zusammenhänge rekonstruiert werden. Daraus werden situationsunabhängige Strukturmomente des Gegenstands Lehren an beruflichen Schulen aber auch komplexe, situationsbezogene subjektive Bedeutungs-Begründungs-Muster abgeleitet. Als wesentliche strukturelle Merkmale lassen sich die Schlüsselkategorien ‚Deutungsmacht‘ und ‚instrumentelle pädagogische Beziehung‘ aus dem empirischen Material unter Zuhilfenahme weiterer theoretischer Folien entwickeln. Da Deutungsmacht auf Akzeptanz angewiesen ist und in instrumentellen Beziehungen eine kooperative Bezugnahme auf den Lehr-Lern-Gegenstand allenfalls punktuell erfolgt, können damit asymmetrische metastabile Arrangements zwischen einer Lehrkraft und Schülerinnen und Schülern verstanden werden. Als empirische Ausprägungen weist Deutungsmacht die Varianten ‚absoluter Anspruch‘, ‚Akzeptanz der Fragilität‘ und ‚Akzeptanz der Legitimität eines Infragestellens‘ auf. Bei der zweiten Schlüsselkategorie treten die Varianten ‚strukturelle Prägung‘, ‚unspezifischer allgemein-menschlicher Charakter‘ und ‚Außenprägung‘ der instrumentellen pädagogischen Beziehung auf. Die Bedeutungs-Begründungs-Musters weisen teilweise Inkonsistenzen und Übergänge in den Positionierungen bezogen auf die dargestellten Varianten auf. Nur bei einem Teil der Muster sind Bemühungen um Wertschätzung und Verstehen der Schülerinnen und Schüler plausibel ableitbar, gleiches gilt in Hinblick auf eine Offenheit für eine Revision der Muster. Die Muster, wie etwa ‚Durchsetzend-ertragendes Nachsteuern‘, ‚Direktiv-personalisierendes Praktizieren‘ oder ‚Regulierend-flexibles Managen‘ sind zu verstehen als Bewältigungsmodi der kontingenten pädagogischen (Konflikt-)Situationen, auf die sich die Fallschilderungen beziehen. Die jeweilige Lehrkraft hat dieses Muster in dem beschriebenen Fall genutzt, was allerdings keine Aussage darüber zulässt, auf welche Muster die Lehrkraft in anderen Fällen zugreifen würde. Die Ergebnisse der vorliegenden Arbeit eignen sich als eine heuristische bzw. theoretische Folie, die Lehrkräfte beim Erschließen ihres eigenen pädagogischen Handelns - etwa in einer als Fallberatung konzipierten Fortbildung - unterstützen kann. Möglich sind Anschlüsse an andere theoretische Ansätze zum Handeln von Lehrkräften aber auch deren veränderte Einordnung. Erweitert werden die Optionen, dieses Handeln über wissenschaftliche Zugänge zu erfassen.
Eye movements serve as a window into ongoing visual-cognitive processes and can thus be used to investigate how people perceive real-world scenes. A key issue for understanding eye-movement control during scene viewing is the roles of central and peripheral vision, which process information differently and are therefore specialized for different tasks (object identification and peripheral target selection respectively). Yet, rather little is known about the contributions of central and peripheral processing to gaze control and how they are coordinated within a fixation during scene viewing. Additionally, the factors determining fixation durations have long been neglected, as scene perception research has mainly been focused on the factors determining fixation locations. The present thesis aimed at increasing the knowledge on how central and peripheral vision contribute to spatial and, in particular, to temporal aspects of eye-movement control during scene viewing. In a series of five experiments, we varied processing difficulty in the central or the peripheral visual field by attenuating selective parts of the spatial-frequency spectrum within these regions. Furthermore, we developed a computational model on how foveal and peripheral processing might be coordinated for the control of fixation duration. The thesis provides three main findings. First, the experiments indicate that increasing processing demands in central or peripheral vision do not necessarily prolong fixation durations; instead, stimulus-independent timing is adapted when processing becomes too difficult. Second, peripheral vision seems to play a prominent role in the control of fixation durations, a notion also implemented in the computational model. The model assumes that foveal and peripheral processing proceed largely in parallel and independently during fixation, but can interact to modulate fixation duration. Thus, we propose that the variation in fixation durations can in part be accounted for by the interaction between central and peripheral processing. Third, the experiments indicate that saccadic behavior largely adapts to processing demands, with a bias of avoiding spatial-frequency filtered scene regions as saccade targets. We demonstrate that the observed saccade amplitude patterns reflect corresponding modulations of visual attention. The present work highlights the individual contributions and the interplay of central and peripheral vision for gaze control during scene viewing, particularly for the control of fixation duration. Our results entail new implications for computational models and for experimental research on scene perception.
Water scarcity, adaption on climate change, and risk assessment of droughts and floods are critical topics for science and society these days. Monitoring and modeling of the hydrological cycle are a prerequisite to understand and predict the consequences for weather and agriculture. As soil water storage plays a key role for partitioning of water fluxes between the atmosphere, biosphere, and lithosphere, measurement techniques are required to estimate soil moisture states from small to large scales.
The method of cosmic-ray neutron sensing (CRNS) promises to close the gap between point-scale and remote-sensing observations, as its footprint was reported to be 30 ha. However, the methodology is rather young and requires highly interdisciplinary research to understand and interpret the response of neutrons to soil moisture. In this work, the signal of nine detectors has been systematically compared, and correction approaches have been revised to account for meteorological and geomagnetic variations. Neutron transport simulations have been consulted to precisely characterize the sensitive footprint area, which turned out to be 6--18 ha, highly local, and temporally dynamic. These results have been experimentally confirmed by the significant influence of water bodies and dry roads. Furthermore, mobile measurements on agricultural fields and across different land use types were able to accurately capture the various soil moisture states. It has been further demonstrated that the corresponding spatial and temporal neutron data can be beneficial for mesoscale hydrological modeling. Finally, first tests with a gyrocopter have proven the concept of airborne neutron sensing, where increased footprints are able to overcome local effects.
This dissertation not only bridges the gap between scales of soil moisture measurements. It also establishes a close connection between the two worlds of observers and modelers, and further aims to combine the disciplines of particle physics, geophysics, and soil hydrology to thoroughly explore the potential and limits of the CRNS method.
This two-wave longitudinal study examined how developmental changes in students’ mastery goal orientation, academic effort, and intrinsic motivation were predicted by student-perceived support of motivational support (support for autonomy, competence, and relatedness) in secondary classrooms. The study extends previous knowledge that showed that support for motivational support in class is related to students’ intrinsic motivation as it focused on the developmental changes of a set of different motivational variables and the relations of these changes to student-perceived motivational support in class. Thus, differential classroom effects on students’ motivational development were investigated. A sample of 1088 German students was assessed in the beginning of the school year when students were in grade 8 (Mean age D 13.70, SD D 0.53, 54% girls) and again at the end of the next school year when students were in grade 9. Results of latent change models showed a tendency toward decline in mastery goal orientation and a significant decrease in academic effort from grade 8 to 9. Intrinsic motivation did not decrease significantly across time. Student-perceived support of competence in class predicted the level and change in students’ academic effort. The findings emphasized that it is beneficial to create classroom learning environments that enhance students’ perceptions of competence in class when aiming to enhance students’ academic effort in secondary school classrooms.
Subcultures creating culture
(2016)
The purpose of this work is to apply the methods of textual semiotics to subcultures, in particular to the little known glam subculture. Subcultures have been the main research field of the Birmingham Centre for Contemporary Cultural Studies, known for its interdisciplinary approach, and for its focus on the creative aspects of subculture. Hebdige, in particular, introduced many semiotic elements in his work, as the aberrant decoding after Eco and the cultural creativity via bricolage after Lévi-Strauss. His definition of subculture as symbolic resistance has been criticized by the following post-subcultural researchers for its abstractness and lack of cohesion.
Semiotics eventually have been expelled from the set of tools used in sociology for the analysis of subcultures. Nowadays, the studies on subcultures have a strong ethnographic focus. Due to terminological proliferation and a descriptive approach, it is difficult to compare them on a common basis.
Textual semiotics, through the concept of semiosphere developed by Lotman, allows to go back to the intuitions of Hebdige, organizing the semiotic elements already present in his work into a wider system of interpretation. The semiosphere offers a coherent theoretical horizon as a basis for further analysis, and a new methodological perspective focusing on the cultural. In this thesis for the first time the work of Lotman is applied to the study of a subculture.
Dietary approaches contribute to the prevention and treatment of type 2 diabetes. High protein diets were shown to exert beneficial as well as adverse effects on metabolism. However, it is unclear whether the protein origin plays a role in these effects. The LeguAN study investigated in detail the effects of two high protein diets, either from plant or animal origin, in type 2 diabetic patients. Both diets contained 30 EN% protein, 40 EN% carbohydrates, and 30 EN% fat. Fiber content, glycemic index, and composition of dietary fats were similar in both diets. In comparison to previous dietary habits, the fat content was exchanged for protein, while the carbohydrate intake was not modified. Overall, both high protein diets led to improvements of glycemic control, insulin sensitivity, liver fat, and cardiovascular risk markers without remarkable differences between the protein types.
Fasting glucose together with indices of insulin resistance were ameliorated by both interventions to varying extents but without significant differences between protein types. The decline of HbA1c was more pronounced in the plant protein group, whereby the improvement of insulin sensitivity in the animal protein group. The high protein intake had only slight influence on postprandial metabolism seen for free fatty acids and indices of insulin secretion, sensitivity and degradation. Except for GIP release, ingestion of animal and plant meals did not provoke differential metabolic and hormonal responses despite diverse circulating amino acid levels.
The animal protein diets led to a selective increase of fat-free mass and decrease of total fat mass, which was not significantly different from the plant protein diet. Moreover, the high protein diets potently decreased liver fat content by 42% on average which was linked to significantly diminished lipogenesis, free fatty acids flux and lipolysis in adipose tissue. Moderate decline of circulating liver enzymes was induced by both interventions. The liver fat reduction was associated with improved glucose homeostasis and insulin sensitivity which underlines the protective effect of the diets.
Blood lipid profile improved in all subjects and was probably related to the lower fat intake. Reductions in uric acid and markers of inflammation further argued for metabolic benefits of both high protein diets. Systolic and diastolic blood pressure declined only in the PP group pointing a possible role of arginine.
Kidney function was not altered by high protein consumption over 6 weeks. The rapid decrease of serum creatinine in the PP group was noteworthy and should be further investigated. Protein type did not seem to play a role but long-term studies are warranted to fully elucidate safety of high protein regimen.
Varying the source of dietary proteins did not affect the mTOR pathway in adipose tissue and blood cells under neither acute nor chronic settings. Enhancement of whole-body insulin sensitivity suggested also no alteration of mTOR and no impairment of insulin sensitivity in skeletal muscle.
A remarkable outcome was the extensive reduction of FGF21, critical regulator of metabolic processes, by approximately 50% independently of protein type. Whether hepatic ER-stress, ammonia flux or rather macronutrient preferences is behind this paradoxical finding remains to be investigated in detail.
Unlike initial expectations and previous reports plant protein based diet had no clear advantage over animal proteins. The pronounced beneficial effect of animal protein on insulin homeostasis despite high BCAA and methionine intake was certainly unexpected assuming more complex metabolic adaptations occurring upon prolonged consumption. In addition, the reduced fat intake may have also contributed to the overall improvements in both groups.
Taking into account the above observed study results, a short-term diet containing 30 EN% protein (either from plant or animal origin), 40 EN% carbohydrates, and 30 EN% fat with lower SFA amount leads to metabolic improvements in diabetic patients, regardless of protein source.
The present work is a case study contributing to the major planning project “Suedlink”. It is structured as follows: first, in a theoretical part, mandatory theories of social acceptance (Wüstenhagen et al., 2007), steps of participation (Münnich, 2014), and the governance theory (Benz and Dose, 2011) are elaborated. Secondly, the relevant methods are discussed. Thirdly, in a qualitative analytical part, the information that were gathered from the expert interviews are analyzed with the use of the aforementioned theories. In the fourth place, an empirical quantitative analysis of data regarding the public acceptance towards Suedlink is presented.
In this case study, with the use of qualitative and quantitative methods, two questions are answered: first, which governance aspects were relevant for the priority use of underground cables for the construction of high voltage direct current transmission lines? For this question, intensive document analysis and different expert interviews were conducted. Secondly, the central question of the present work addresses the question whether local or/and individual factors affect the public acceptance towards SüdLink. Here, in particular, it is interesting to analyze if the priority use of underground cables affected the people’s acceptance towards SuedLink. In order to respond to both questions, an online survey was conducted among citizen initiatives, district administrators, and individuals in social media during March till July 2016. Thereafter, the data was analyzed with the use of descriptive quantitative methods. The data shows, that underground cables not necessarily increase public acceptance (see also Menges and Beyer, 2013). On the contrary, individual and local criteria were relevant for the survey respondents. For example criteria such as the quality of participation, distance between home and transmission lines, and the additional financial burden (taxes, higher prices for electricity) were important for the evaluation. In addition, survey respondents who participated in citizen initiatives were more critical against the priority use of underground cables and SuedLink in general. Likewise, residential homeowners rejected every form of transmission lines.
Durch die Zunahme metabolischer Stoffwechselstörungen und Erkrankungen in der Weltbevölkerung wird in der Medizin und den Lebenswissenschaften vermehrt nach Präventionsstrategien und Ansatzpunkten gesucht, die die Gesundheit fördern, Erkrankungen verhindern helfen und damit auch die Gesamtlast auf die Gesundheitssysteme erleichtern. Ein Ansatzpunkt wird dabei in der Ernährung gesehen, da insbesondere der Konsum von gesättigten Fetten die Gesundheit nachträglich zu beeinflussen scheint. Dabei wird übersehen, dass in vielen Studien Hochfettdiäten nicht ausreichend von den Einflüssen einer zum Bedarf hyperkalorischen Energiezufuhr getrennt werden, sodass die Datenlage zu dem Einfluss von (gesättigten) Fetten auf den Metabolismus bei gleichbleibender Energieaufnahme noch immer unzureichend ist.
In der NUtriGenomic Analysis in Twins-Studie wurden 46 Zwillingspaare (34 monozygot, 12 dizygot) über einen Zeitraum von sechs Wochen mittels einer kohlenhydratreichen, fettarmen Diät nach Richtlinien der Deutschen Gesellschaft für Ernährung für ihr Ernährungsverhalten standardisiert, ehe sie zu einer kohlenhydratarmen, fettreichen Diät, die insbesondere gesättigte Fette enthielt, für weitere sechs Wochen wechselten. Beide Diäten waren dem individuellen Energiebedarf der Probanden angepasst, um so sowohl akut nach einerWoche als auch längerfristig nach sechs Wochen Änderungen des Metabolismus beobachten zu können, die sich in der vermehrten Aufnahme von (gesättigten) Fetten begründeten.
Die über die detaillierte Charakterisierung der Probanden an den klinischen Untersuchungstagen generierten Datensätze wurden mit statistischen und mathematischen Methoden (z.B. lineare gemischte Modellierung) analysiert, die der Größe der Datensätze und damit ihrem Informationsvolumen angepasst waren.
Es konnte gezeigt werden, dass die metabolisch gesunden und relativ jungen Probanden, die eine gute Compliance zeigten, im Hinblick auf ihren Glukosestoffwechsel adaptieren konnten, indem die Akutantwort nach einer Woche im Nüchterninsulin und dem Index für Insulinresistenz in den weiteren fünf Wochen ausgeglichen wurde.
Der Lipidstoffwechsel in Form der klassischen Marker wie Gesamtcholesterin, LDL und HDL war dagegen stärker beeinflusst und auch nach insgesamt sechs Wochen deutlich erhöht.
Letzteres unterstützt die Beobachtung im Transkriptom des weißen, subkutanen Fettgewebes, bei der eine Aktivierung der über die Toll-like receptors und das Inflammasom vermittelten subklinischen Inflammation beobachtet werden konnte.
Die auftretenden Veränderungen in Konzentration und Komposition des Plasmalipidoms zeigte ebenfalls nur eine teilweise und auf bestimmte Spezies begrenzte Gegenregulation.
Diesbezüglich kann also geschlussfolgert werden, dass auch die isokalorische Aufnahme von (gesättigten) Fetten zu Veränderungen im Metabolismus führt, wobei die Auswirkungen in weiteren (Langzeit-)Studien und Experimenten noch genauer untersucht werden müssen. Insbesondere wäre dabei ein längerer Zeitraum unter isokalorischen Bedingungen von Interesse und die Untersuchung von Probanden mit metabolischer Vorbelastung (z.B. Insulinresistenz).
Darüber hinaus konnte in NUGAT aber ebenfalls gezeigt werden, dass die Nutrigenetik und Nutrigenomik zwei nicht zu vernachlässigende Faktoren darstellen. So zeigten unter anderem die Konzentrationen einiger Lipidspezies eine starke Erblichkeit und Abhängigkeit der Diät.
Zudem legen die Ergebnisse nahe, dass laufende wie geplante Präventionsstrategien und medizinische Behandlungen deutlich stärker den Patienten als Individuum mit einbeziehen müssen, da die Datenanalyse interindividuelle Unterschiede identifizierte und Hinweise lieferte, dass einige Probanden die nachteiligen, metabolischen Auswirkungen einer Hochfettdiät besser ausgleichen konnten als andere.