334 research outputs found
Givenness and the Licensing of Object-First Order in German: The Effect of Referential Form
This paper presents two experiments investigating how the referential form of the object NP affects the acceptability of German main clauses starting with either the subject or direct object. The main clause was always preceded by a context sentence introducing a human referent to which the object NP of the following sentence referred. Results show higher acceptability for SO order when the object is a personal pronoun, higher acceptability for OS order when the object is a d-pronoun, and equal acceptability for SO and OS order when the object is a demonstrative NP. We discuss the results in the context of current theories of how word order variation depends on properties of the preceding context
Efficient coupling to an optical resonator by exploiting time-reversal symmetry
The interaction of a cavity with an external field is symmetric under time
reversal. Thus, coupling to a resonator is most efficient when the incident
light is the time reversed version of a free cavity decay, i.e. when it has a
rising exponential shape matching the cavity lifetime. For light entering the
cavity from only one side, the maximally achievable coupling efficiency is
limited by the choice of the cavity mirrors' reflectivities. Such an
empty-cavity experiment serves also as a model system for single-photon
single-atom absorption dynamics. We present experiments coupling exponentially
rising pulses to a cavity system which allows for high coupling efficiencies.
The influence of the time constant of the rising exponential is investigated as
well as the effect of a finite pulse duration. We demonstrate coupling 94% of
the incident TEM00 mode into the resonator.Comment: 7 pages, 5 figure
Global renewable energies: a dynamic study of implementation time, greenhouse gas emissions and financial needs
The current worldwide energy consumption is largely dominated by non-renewable energies such as coal, oil and gas. For well-known reasons, this concept should be changed to a more sustainable one based on renewables. As learned from history, a transition from one energy system to another has always taken about 100years. A dynamic material flow model is developed to simulate some key elements for the implementation of renewable energy systems on a large scale. These key elements are the required industrial capacity, the energy and financial requirements and the impact on greenhouse gas mitigation. Results are presented for wind, photovoltaic, hydro, solar thermal, geothermal and biomass electrical energy systems. The comparison of two different implementation strategies, moderate ≈60years and fast ≈30years, shows that the implementation time is the only limitation, resulting in large production overcapacities. The energy and financial needs are not as critical. The implementation of renewables on a large scale would considerably reduce CO2 emissions by 2tons per person per year for a world population of 7billion peopl
Experimentelle Untersuchungen zur photodynamischen Therapie mit 5-Aminolävulinsäure im CAM-Modell
Im Rahmen der Arbeit wurde durch experimentelle Grundlagenuntersuchungen das tierversuchsnahe Modell der Chorioallantoismembran des bebrüteten Hühnereis (CAM-Modell) im Hinblick auf seine Eignung für in-vivo-Studien zur photodynamischen Therapie mit 5-Aminolävulinsäure evaluiert.
Ein für die Quantifizierung wellenlängenabhängiger Effekte und variabler Bestrahlungsparameter geeigneter Versuchsrahmen wurde etabliert.
Die Ergebnisse der fluoreszenzkinetischen Untersuchungen zeigen, dass das CAM-Modell zur Echtzeitbeobachtung der Dynamik der Umsetzung von 5-Aminolävulinsäure in photosensibilisierende Porphyrine sowie zur selektiven Erfassung der Anreicherung der Photoprodukte und deren quantitative Auswertung geeignet ist.
Die durch photodynamische Therapie an der CAM induzierten makroskopisch und mikroskopisch verifizierbaren Schäden wurden beschrieben und miteinander verglichen. Die vier unterschiedlichen Grade makroskopisch festgestellter Gefäßveränderungen unter photodynamischer Therapie wurden in einem Bewertungsscore subsumiert, welcher eine semiquantitative Auswertung der Schäden ermöglicht.
Die Wertigkeit dieses makroskopischen Bewertungsscores für die Beurteilung des Ausmaßes der an der CAM induzierten Schäden wurde durch Korrelation mit den histologischen Veränderungen untermauert.
Die Auswertung der durch photodynamischer Therapie induzierten Schäden in ihrem zeitlichen Verlauf ergab ein für weitere experimentele Beobachtungen relevantes Zeitfenster von 48 Stunden: Sämtliche Schäden entwickelten sich innerhalb dieses Zeitraumes.
Ein Vergleich der Bestrahlung mit Weißlicht und Laserlicht (Farbstofflaser: 633nm) ergab bei gleicher Bestrahlungsstärke stärkere phototoxische Schäden durch Bestrahlung mit Laserlicht
The Effect of Clause Type on Long Extraction in German
Long extraction is the movement of a phrase over a clausal boundary. Although long extraction into embedded clauses used to be acceptable in previous stages of German, it is considered to be unacceptable in Modern German. In this paper, we first review experimental evidence from our ongoing investigation of long extraction in Modern German. We then present a new experiment which compares the acceptability of the four major types of long extraction: long topicalization, long extraction into comparative clauses, embedded wh-questions and relative clauses. In accordance with the prior literature, the results indicate that long extraction is of marginal acceptability in Modern German. Long extraction into comparative clauses was found to be most acceptable, followed by embedded wh-questions. Long extraction into relative clauses and long topicalization received the lowest acceptability ratings. Overall, the results show that long extraction into embedded clauses is no less acceptable than long extraction into main clauses. The experimental findings are corroborated by observations from a corpus study
Personal Pronouns and D-Pronouns in German: Connecting Comprehension to Production
We review recent experiments and corpus data from our ongoing investigation of p(ersonal) and d(emonstrative) pronouns. Contrary to a widespread belief, d-pronouns did not always refer to non-topical antecedents in case of referential ambiguity. More generally, the data that we review show that a complex interplay of factors governs the processing of p-pronouns and d-pronouns. During language comprehension, syntactic function, position, and topichood of the antecedent are all taken into account when interpreting a p- or d-pronoun. Similarly, the choice between p- and d-pronoun during language production is heavily influenced by these three factors. We propose an interpretation and a production rule for d-pronouns, both based on prominence features. For interpretation, the proposed rule simply counts prominence features and assigns the d-pronoun the antecedent that is least prominent. For production, we propose a similar rule for choosing between a p- and d-pronoun for referring to a given antecedent. In contrast to interpretation, the rule for choosing a pronominal form makes use of weighted prominence features and relates prominence to production frequency in an exponential way
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