2,798 research outputs found
Language and mediality : on the medial status of "everyday language"
The medium of (oral) language is mostly disregarded (or overlooked) in contemporary media theories. This "ignoring of language" in media studies is often accompanied by an inadequate transport model of communication, and it converges with an "ignoring of mediality" in mentalistic theories of language. In the present article it will be argued that this misleading opposition of language and media can only be overcome if one already regards oral language, not just written language, as a medium of the human mind. In my argumentation I fall back on Wittgenstein’s conception of language games to try to show how Wittgenstein’s ideas can help us to clear up the problem of the mediality of language and also to show to what extent the mentalistic conception of Chomskyan provenance cannot be adequate to the phenomenon of language
Modelling International Bond Markets with Affine Term Structure Models
This paper investigates the performance of international affine term structure models (ATSMs) that are driven by a mutual set of global state variables. We discuss which mixture of Gaussian and square root processes is best suited for modelling international bond markets. We derive necessary conditions for the correlation and volatility structure of mixture models to accommodate various empirical stylized facts such as the forward premium puzzle and differently shaped yield curves. Using UK-US data we estimate international ATSMs taking into account the joint transition density of yields and exchange rates without assuming normality. We find strong empirical evidence for negatively correlated global factors in international bond markets. Further, the empirical results do not support the existence of local factors in the UK-US setting, suggesting that diversification benefits from holding currency- hedged bond portfolios in these markets are likely to be small. Altogether, we find that mixture models greatly enhance the performance of ATSMs.International affine term structure models, Estimation, Exchange rate, Model Selection
The impact of profit taxation on capitalized investment with options to delay and divest
In entrepreneurial decisions making uncertain future profits often are a main characteristics of real investment opportunities. If investors can react to uncertainty the degree of irreversibility and timing flexibility inherent in the available project should be integrated into the decision calculus. In this paper we investigate the interdependencies of effects from profit taxation and real options. We model an investment decision including an option to invest and an option to abandon. We show that increasing the tax rate can lead to paradoxical tax effects, i.e. may foster an investor's willingness to invest into a capitalized investment. Instead, if we abstract from the possibility to abandon the investment object such paradoxical effect cannot be identified. Determining the after-tax value of the option to enter the investment project with and without an abandonment option we receive a critical cash flow cutoff level. We find that the value of the option to abandon depends on the tax rate and the amount of periodical cash flows. The option value can be increasing or decreasing in the tax rate. We find scenarios with paradoxical tax effects and show that the observed paradoxical effects are due to the presence of the real abandonment option itself. This finding contributes to the stream of literature that explains potential sources of paradoxical tax effects. The generated decision rules are helpful for investors facing risky investment opportunities and for discussing the economic impact of tax reforms. Furthermore, we highlight the overwhelming importance of integrating taxes in typically applied valuation approaches. --investment decisions,real options,tax effects,timing flexibility,,uncertainty
Semiclassical theory of the interaction correction to the conductance of antidot arrays
Electron-electron interactions are responsible for a correction to the
conductance of a diffusive metal, the "Altshuler-Aronov correction" . Here we study the counterpart of this correction for a ballistic
conductor, in which the electron motion is governed by chaotic classical
dynamics. In the ballistic conductance, the Ehrenfest time enters as
an additional time scale that determines the magnitude of quantum interference
effects. The Ehrenfest time effectively poses a short-time threshold for the
trajectories contributing to the interaction correction. As a consequence,
becomes exponentially suppressed if the Ehrenfest time is
larger than the dwell time or the inverse temperature. We discuss the explicit
dependence on Ehrenfest time in quasi-one and two-dimensional antidot arrays.
For strong interactions, the sign of may change as a function
of temperature for temperatures in the vicinity of .Comment: 20 pages, 10 figures, published versio
[On the normativity of language rules : is speaking a "rule-governed" activity?]
Ausgangspunkt: Die Kritik am "Zwei-Welten-Modell": Die grundlegende linguistische Unterscheidung zwischen "Sprache" und "Sprechen" ist im Rahmen der neueren Debatten um Sprachmedialität wieder verstärkt thematisiert und kritisiert worden. Lässt sich dieses schulbildende, in der Linguistik geradezu eherne Begriffspaar überhaupt noch sinnvollerweise aufrechterhalten? Oder muss es mindestens umdefiniert, vielleicht sogar gänzlich verworfen werden? Hat sich insbesondere die auf Chomsky zurückgehende Unterscheidung von Sprachkompetenz und -performanz nicht von selbst ad absurdum geführt, nachdem der linguistische Kognitivismus chomskyscher Provenienz Sprache als lebendiges Phänomen, als Medium menschlicher Kommunikation, vollständig aus dem Blick verloren hat? Führt nicht schon die scheinbar harmlose linguistische Differenzierung zwischen einer Sprachregel und ihrer Anwendung zu einer irreführenden und unangemessenen Verdinglichung von Sprache? ...In her book Sprache, Sprechakt, Kommunikation  S. Krämer argues that most linguistic theories of the twentieth century can be put into two categories: proponents and opponents of a language conception she calls the "Zwei-Welten-Modell". Krämer herself rejects this model, which has – as she points out – two main characteristics:
1) "Language" and "speech" constitute a dualistic schema. In this sense there is "a language behind speech".
2) Language precedes speech, competence precedes performance – logically and genealogically.
I agree with Krämer's rejection of this model, but the conclusions she draws are too far-reaching in my opinion. Rejecting the "Zwei-Welten-Modell", she takes too strong a stand for performance, so that her own argumentation becomes one-sided and is not able to grasp the structural and the normative aspect of language sufficiently. For instance, she appeals to Wittgenstein in this context to claim that language rules are not normative at all, not even in the sense of felicity conditions in speech act theories (Krämer 2001: 130). My paper can be understood as a critical reply to this radical anti-normativism formulated by Krämer. Such an anti-normativism is neither plausible, nor is it Wittgenstein's view. As an alternative to this I try to develop a view that takes into account the normative aspect of rule-following without getting caught up in the misleading "Zwei-Welten-Modell". Here I focus on the concept of implicit rules. Is it totally wrong to say that speaking is a "rule-governed" activity? If not, what does "rule-governed" mean in this context? Krämer's criticism of the "Zwei-Welten-Modell" is right; but the speech act theory is too fruitful to be thrown overboard without further ado
Von free-floatendem Kapital, Hardlinern und Instructions : linguistische Anmerkungen zur populären Anglizismenkritik
Die Themen Sprachrichtigkeit und Sprachidentität haben in Deutschland seit einiger Zeit Hochkonjunktur. Der 'Sprachpfleger' Bastian Sick, in der massenmedialen Berichterstattung stereotyp als gleichermaßen "kompetent" wie "lustig" und "gar nicht oberlehrerhaft" angepriesen, verkauft seine Kolumnensammlungen millionenfach und füllt bei seinen Lesungen mühelos ganze Konzertsäle. Der Verein Deutsche Sprache, Speerspitze der Anglizismenkritik im deutschsprachigen Raum, hat nach eigenen Angaben mittlerweile fast 30.000 Mitglieder. Betrachtet man diese Protagonisten des öffentlichen Sprachdiskurses aus linguistischer Perspektive, so stellt man fest, dass sich die von ihnen propagierte Sprachauffassung in der Regel an einer alten Metapher orientiert – der biologistischen Metapher von Sprache als einem Organismus: Ein Organismus kann geboren werden und sterben; er kann krank werden und verfallen, er ist – um es mit einem Ausdruck von Jürgen Spitzmüller zu sagen – eine klar "abgrenzbare Einheit". Ein Sprachsystem erscheint somit als ein abgeschlossenes organisches Gebilde, welches es zu erhalten gilt und das durch schädliche Einflüsse von außen in seiner Identität gefährdet ist
Die Unhintergehbarkeit der 'normalen Sprache' : ein Beitrag zum Medienbegriff
Nicht zuletzt durch die Entwicklung und Verbreitung der sogenannten Neuen Medien ist das Thema 'Medialität' im gesamten Bereich der Geistes- und Kulturwissenschaften virulent geworden. Im Rahmen der aktuellen Diskurse um den Begriff des Mediums ist zu beobachten, daß dieser Ausdruck häufig unterschiedslos auf so verschiedene Referenzobjekte wie Internet, Fernsehen, Printmedien, Computer, Schrift, Bilder, Schallwellen u. v. a. bezogen wird. Das Medium orale Sprache gerät dabei sonderbarerweise häufig aus dem Blickfeld. - Warum ist dies so
Gibt es nichtmediale Kommunikation?
Ziel des vorliegenden Aufsatzes ist es, zu einer neuerlichen Diskussion der Begriffe 'Medium' und 'Kommunikation' in der Linguistik beizutragen. Dabei versuche ich insbesondere, den philosophisch-kulturwissenschaftlichen Diskurs, in welchem die Themen 'Medialität' und 'Perfonnanz' seit längerer Zeit intensiv diskutiert werden, zu dem in der Angewandten Linguistik geläufigen Modell der Kommunikationsformen in Beziehung zu setzen und Möglichkeiten einer Verbindung dieser beiden Diskurse zumindest anzudeuten. Der Aufsatz gliedert sich in vier Abschnitte: Zunächst werden einige geläufige Mediendefinitionen vorgestellt. Im zweiten Kapitel stelle ich dann die Frage 'Ist Kommunikation ein Transportvorgang?', um auf dieser Grundlage im dritten Kapitel eine alternative Medienkonzeption vorzustellen. Im letzten Kapitel wird dieser Medienbegriff dann sowohl vom Begriff des Zeichensystems, als auch von dem der Kommunikationsform abgegrenzt
pkaPS: prediction of protein kinase A phosphorylation sites with the simplified kinase-substrate binding model
BACKGROUND: Protein kinase A (cAMP-dependent kinase, PKA) is a serine/threonine kinase, for which ca. 150 substrate proteins are known. Based on a refinement of the recognition motif using the available experimental data, we wished to apply the simplified substrate protein binding model for accurate prediction of PKA phosphorylation sites, an approach that was previously successful for the prediction of lipid posttranslational modifications and of the PTS1 peroxisomal translocation signal. RESULTS: Approximately 20 sequence positions flanking the phosphorylated residue on both sides have been found to be restricted in their sequence variability (region -18...+23 with the site at position 0). The conserved physical pattern can be rationalized in terms of a qualitative binding model with the catalytic cleft of the protein kinase A. Positions -6...+4 surrounding the phosphorylation site are influenced by direct interaction with the kinase in a varying degree. This sequence stretch is embedded in an intrinsically disordered region composed preferentially of hydrophilic residues with flexible backbone and small side chain. This knowledge has been incorporated into a simplified analytical model of productive binding of substrate proteins with PKA. CONCLUSION: The scoring function of the pkaPS predictor can confidently discriminate PKA phosphorylation sites from serines/threonines with non-permissive sequence environments (sensitivity of ~96% at a specificity of ~94%). The tool "pkaPS" has been applied on the whole human proteome. Among new predicted PKA targets, there are entirely uncharacterized protein groups as well as apparently well-known families such as those of the ribosomal proteins L21e, L22 and L6. AVAILABILITY: The supplementary data as well as the prediction tool as WWW server are available at . REVIEWERS: Erik van Nimwegen (Biozentrum, University of Basel, Switzerland), Sandor Pongor (International Centre for Genetic Engineering and Biotechnology, Trieste, Italy), Igor Zhulin (University of Tennessee, Oak Ridge National Laboratory, USA)
Portfolio construction in university teacher education : Design, implementation, and evaluation of a portfolio-based instructional system for deep learning
Portfolio construction has come to be an integral element of teacher education programs around the world. The conceptualizations and the concretizations of portfolio-based learning environments – in theory as well as in practice – show considerable diversity. Studies reporting substantive original research on the effectiveness of portfolio as an approach for learning and instruction in teacher education continue to be scarce; their research focuses and, thus, their contents are rather mixed. Yet, there is also an element of similarity: The evidence available on the effects of portfolio construction – as identified and reviewed for this dissertation – is predominantly positive. Thus, it seems warranted to continue implementing portfolio in teacher education practice and to further research its effects.
The aim of this dissertation is to contribute to the theory and practice of teacher education in higher education settings by investigating portfolio as an educational tool, and by evaluating one particular portfolio-based learning environment designed for and implemented in initial teacher education. To this end, after an initial clarification of key concepts, essential theories, and fundamental terminology, available empirical studies were systematically researched, identified, analyzed, and collated on an international scale. Then, on the basis of various theoretical approaches, portfolio concepts, and relevant empirical research findings, a concrete portfolio-based learning environment was designed, implemented, and evaluated in the context of university teacher education for vocational schools.
The review of original research considered to be of adequate explanatory power confirms a major criticism repeatedly noted in the literature, i.e., that there still seems to exist a limited body only of substantive research of portfolio as an educational instrument for the design of learning environments. This means that both the current evidence on portfolio and the common practice of portfolio construction are in need of additional substantiation. The findings of the study conducted suggest that the portfolio-based learning environment designed for university teacher education has the potential to support both students’ learning and their reflection.
This dissertation contributes to the theory and practice of teacher education – both in general and for vo-cational schools in particular – by means of a comprehensive, critical synthesis of available portfolio literature and findings of original research and by the investigation of one concrete portfolio-based learning environment in one clearly specified context of university teacher education. In addition, this dissertation provides a contribution to teacher educators’ everyday practice, proposing the principles and details of the design of a portfolio-based learning environment successfully implemented to support students’ reflective learning in university teacher education
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