Optimal Stopping with Dynamic Variational Preferences

We consider optimal stopping problems in uncertain environments for an agent assessing utility by virtue of dynamic variational preferences or, equivalently, assessing risk by dynamic convex risk measures. The solution is achieved by generalizing the approach in terms of multiple priors introducing the concept of variational supermartingales and an accompanying theory. To illustrate results, we consider prominent examples: dynamic entropic risk measures and a dynamic version of generalized average value at risk.optimal Stopping, Uncertainty, Dynamic Variational Preferences, Dynamic Convex Risk Measures, Dynamic Penalty, Time-Consistency, Entropic Risk, Average Value at Risk

Merging of Opinions under Uncertainty

We consider long-run behavior of agents assessing risk in terms of dynamic convex risk measures or, equivalently, utility in terms of dynamic variational preferences in an uncertain setting. By virtue of a robust representation, we show that all uncertainty is revealed in the limit and agents behave as expected utility maximizer under the true underlying distribution regardless of their initial risk anticipation. In particular, risk assessments of distinct agents converge. This result is a generalization of the fundamental Blackwell-Dubins Theorem, cp. [Blackwell & Dubins, 62], to convex risk. We furthermore show the result to hold in a non -time-consistent environment.Dynamic Convex Risk Measures, Multiple Priors, Uncertainty, Robust Representation, Time-Consistency, Blackwell-Dubins.

Merging of Opinions under Uncertainty

We consider long-run behavior of agents assessing risk in terms of dynamic convex risk measures or, equivalently, utility in terms of dynamic variational preferences in an uncertain setting. By virtue of a robust representation, we show that all uncertainty is revealed in the limit and agents behave as expected utility maximizer under the true underlying distribution regardless of their initial risk anticipation. In particular, risk assessments of distinct agents converge. This result is a generalization of the fundamental Blackwell-Dubins Theorem, cp. [Blackwell & Dubins, 62], to convex risk. We furthermore show the result to hold in a non-time-consistent environment.Dynamic Convex Risk Measures, Multiple Priors, Uncertainty, Robust Representation, Time-Consistency, Blackwell-Dubins

the consumer model in jurisdiction and science

Titelblatt, Inhaltsverzeichnis, Lebenslauf 1\. Einleitung 2\. Der Verbraucher im Recht 3.1 Qualitätswahrnehmung Teil 1 3.2 Qualitätswahrnehmung Teil 2 3.3 Qualitätswahrnehmung Teil 3 3.4 Qualitätswahrnehmung Teil 4 4\. Diskussion 5\. Zusammenfassung / Summary 6\. LiteraturDas vom Europäischen Gerichtshof (EuGH) in seinen Entscheidungen entwickelte Verbraucherleitbild des ?durchschnittlich informierter, aufmerksamer und verständiger Durchschnittsverbrauchers? wird in der vorliegenden Arbeit anhand von Befunden aus der Konsumentenforschung kritisch überprüft. Insbesondere wird der Frage nachgegangen, ob die Qualitätswahrnehmung bei Lebensmittelkäufen in der vom EuGH zugrunde gelegten Form real existiert oder lediglich eine Idealvorstellung darstellt. Zu diesem Zweck wird zunächst das Verbraucherleitbild des EuGH im Hinblick auf die Qualitätswahrnehmung bei Lebensmitteln analysiert und vom Leitbild des flüchtigen deutschen Durchschnittsverbrauchers abgegrenzt. Dem besseren Verständnis dient ein grober Überblick der rechtlichen Grundlagen, sowohl in Deutschland als auch in der EU. Die Besprechung von Forschungsergebnissen zur Qualitätswahrnehmung bei Lebensmitteln beschäftigt sich im ersten Teil mit grundlegenden Erkenntnissen zum Wahrnehmungs- und Informationsverhalten der Konsumenten. Dabei wird deutlich, dass es sich bei der Produktwahrnehmung des Verbrauchers um einen subjektiven und selektiven Vorgang handelt, den eine Vielzahl von Faktoren beeinflusst. Der Aufnahme und Verarbeitung aller angebotenen Informationen stehen sowohl die begrenzten Kapazitäten der Verbraucher als auch deren Entlastungsstreben entgegen. Die Betrachtung der speziellen Qualitätswahrnehmungsabläufe bei Lebensmitteln im zweiten Teil beginnt mit einer Abhandlung zum vielschichtigen und kontrovers diskutierten Begriff der Lebensmittelqualität. Das als objektiv angesehene, auf physiko-chemischen und sensorischen Analysen beruhende Verständnis der Lebensmittelqualität unterscheidet sich von der subjektiv wahrgenommenen Lebensmittelqualität, wie sie dem Verbraucher als Basis zur Präferenzbildung dient. Obwohl die Qualität eines Lebensmittels, bedingt durch die Vielzahl der einwirkenden Faktoren und die individuell unterschiedliche Meinungsbildung, von jedem Menschen anders gesehen wird, folgt der eigentliche Wahrnehmungsvorgang bestimmten Regeln und lässt sich theoretisch darstellen. Da nicht alle den Käufer interessierenden Produkteigenschaften zum Zeitpunkt des Kaufs zugänglich sind, bedient sich der Verbraucher sogenannter Qualitätsindikatoren. Durch den indirekten Charakter der Merkmalserfassung treten nachweislich Fehler auf, weshalb die Verbraucher die Beschaffenheit von Lebensmitteln vor einem Kauf nicht immer korrekt ermitteln. Hieraus kann sich eine falsche Produkterwartung ableiten, die unter Umständen zu einer veränderten Wahrnehmung des tatsächlichen Produkterlebnisses führt. Wenn solche Fehlperzeptionen bei nicht verifizierbaren Eigenschaften (sogenannten Glaubenseigenschaften) auftreten, lassen sie sich durch Produkterfahrungen, auch auf längere Sicht, nicht korrigieren. Begünstigt wird die Fehlbeurteilung von Lebensmitteln durch die Fülle und Unübersichtlichkeit des derzeitigen Informationsangebotes, welches die Kapazitäten der Verbraucher nur unzureichend berücksichtigt, sowie durch das Wissen der Anbieter um die Möglichkeiten, wie sie Wahrnehmungsverschiebungen herbeiführen. Obwohl eine steigende Qualitätsorientierung der Verbraucher besteht, wirken sich in der Regel auch qualitätsunabhängige Faktoren auf den Lebensmittelkauf aus. Neben bestimmten Gewohnheiten und sozialen Komponenten verhindern vor allem Kostenfaktoren, dass die präferierte Qualität erworben wird. Letzere umfassen neben finanziellen Auslagen auch Aufwendungen anderer Art, zum Beispiel zusätzlicher Zeitaufwand und Wege. Trotz erheblicher Informationsmengen und dem Empfinden einer tendenziell abnehmenden Qualität des Gesamtangebotes sehen sich die Verbraucher in den meisten Fällen als relativ kompetente Marktpartner und halten sich demnach für fähig, erfolgreiche Entscheidungen zu fällen. Verunsichernd wirken vermeintliche und reale Gesundheitsrisiken, denen die meisten Konsumenten aber mit einer zuversichtlichen Beurteilung ihrer persönlichen Risiken (?optimistic bias?) begegnen. Die kritische Überprüfung des Verbraucherleitbildes des EuGH ergibt, dass dem Käufer zwar durchaus ein verstärktes Interesse an Qualität und Qualitätsinformationen unterstellt werden darf, die vom EuGH vorausgesetzte Verständigkeit und Informiertheit unter den derzeitigen Bedingungen aber weit hinter der juristischen Fiktion zurückbleibt.The consumer model of an average consumer, who is reasonably well informed and reasonably observant and circumspect, which the European Court of Justice (EuGH) has developed in its decisions, is critically reviewed with the aid of results from consumer research. Of special interest is the question, whether the quality perception process of foodstuffs, as seen by the EuGH, represents reality or merely an ideal concept. First of all, the European Court?s consumer model is analyzed with respect to the quality perception of foodstuffs and differentiated from the consumer model of the careless German average consumer. For a better understanding a brief overview of the legal basis in Germany as well as in the European Community (EC) is given. The first section of the discussion from results of consumer research concerning the quality perception process of foods comprises basic findings about the way consumers acquire and process information. It becomes clear that product perception is a subjective and selective process, which is influenced by a large number of variables. The complete acquisition and processing of all the information offered is prevented by the limited capacities of consumers and their tendency to strive for relief. The second part, which deals with the specific quality perception process of foodstuffs, starts out with a discussion of the multifaceted and highly controversial concept of food quality. The objective understanding of food quality, which is based on physical, chemical and sensory analysis must be differentiated from the subjective perception of food quality as it serves the consumer in his/her purchasing preferences. Even though each individual due to the numerous factors influencing the quality perception and the individual way of attitude development sees the quality of foods differently, the actual process follows certain rules and can be theoretically described. As not all product characteristics of interest can be observed at the point of purchase, the consumer makes use of (so called) quality cues. Due to this indirect way of information gathering consumers make mistakes, and do not always deduce the true nature of a food product. This can result in false product expectations, which under certain circumstances may lead to an deluded product experience. If such misconceptions occur in connection with product characteristics, which cannot be verified (credence dimensions), correction of these misconceptions with the aid of product experience will be impossible even in the long run. False judgements are promoted by the abundance and complexity of the current information, which does not sufficiently take into acount the limited capabilities of buyers, and by the suppliers? knowledge of the possibility of intentionally shifting consumers? perception. Even though consumers show a growing quality consciousness, quality independent factors influence the food shopping behavior as well. Besides certain habits and social conditioning, the costs of food prevent people form getting their preferred quality. The cost factor comprises financial expenses as well as time and convenience expenditures. Despite considerable information and a feeling of diminishing quality of the food supply, consumers believe themselves to be quite competent and capable of making effective purchasing decisions. Concerns are caused by true and supposed health risks, which most consumers will however face with an optimistic bias regarding their personal risks. The critical review of the European Court?s consumer model reveals that the buyers do show a growing interest in food quality and accurate quality information, but that the consumer?s in their reasoning and knowledge do not, under current conditions, meet the expectations of the EuGH, that is the consumers remain significantly behind the judicial model

A Quasi-Exclusive Measurement of Carbon-12 (Carbon-12, 3alpha)x at 2.1 Gev/Nucleon.

The cross section, (sigma)((\u2712)C + T (---\u3e) 3(alpha) + X) or (sigma)(3(alpha)), and excitation energy spectrum, d(sigma)(3(alpha))/dE(\u27*), for (\u2712)C have been measured for 2.1 GeV/nucleon (\u2712)C using a 0.9(g/cm(\u272)) target of (\u2712)C. The d(sigma)(3(alpha))/dE(\u27*) spectrum was found to include excitation energies in excess of 50 MeV. The dissociation of (\u2712)C into three (3) alpha particles at these excitation energies is evidence for clustering in the (\u2712)C nucleus

On Dynamic Coherent and Convex Risk Measures : Risk Optimal Behavior and Information Gains

We consider tangible economic problems for agents assessing risk by virtue of dynamic coherent and convex risk measures or, equivalently, utility in terms of dynamic multiple priors and dynamic variational preferences in an uncertain environment. Solutions to the Best-Choice problem for a risky number of applicants are well-known. In Chapter 2, we set up a model with an ambiguous number of applicants when the agent assess utility with multiple prior preferences. We achieve a solution by virtue of multiple prior Snell envelopes for a model based on so called assessments. The main result enhances us with conditions for the ambiguous problem to possess finitely many stopping islands. In Chapter 3 we consider general optimal stopping problems for an agent assessing utility by virtue of dynamic variational preferences. Introducing variational supermartingales and an accompanying theory, we obtain optimal solutions for the stopping problem and a minimax result. To illustrate, we consider prominent examples: dynamic entropic risk measures and a dynamic version of generalized average value at risk. In Chapter 4, we tackle the problem how anticipation of risk in an uncertain environment changes when information is gathered in course of time. A constructive approach by virtue of the minimal penalty function for dynamic convex risk measures reveals time-consistency problems. Taking the robust representation of dynamic convex risk measures as given, we show that all uncertainty is revealed in the limit, i.e. agents behave as expected utility maximizers given the true underlying distribution. This result is a generalization of the fundamental Blackwell-Dubins theorem showing coherent as well as convex risk measures to merge in the long run

Visual wulst influences on flash evoked responses in the ectostriatum of the zebra finch

Engelage J, Bischof H-J. Visual wulst influences on flash evoked responses in the ectostriatum of the zebra finch. Brain Research. 1994;652(1):17-27.Anatomical data suggest that visual information from the thalamofugal pathway contributes to visual processing in the tectofugal pathway. We addressed the question of the functionality of anatomically described connections to the visual system of a laterally eyed bird, the zebra finch. The study shows the contribution of visual wulst efferents to visual processing in the ectostriatum by recordings of visually evoked slow field potentials. Suppression of visual wulst activity resulted in a selective reduction of distinct potential components in contralaterally evoked slow field potentials. A clear reduction was observed in the maximum amplitude of short latency components in the negative wave. Long latency components of the negative wave and the entire positive wave of the contralaterally flash evoked potentials were almost abolished. Ipsilateral visual evoked potentials (VEPs) were not significantly affected. Cooling and spreading depression of the optic tectum resulted in a uniform amplitude reduction of the negative wave. The positive wave was almost abolished. Ipsilateral VEPs disappeared completely during suppression of optic tectum activity. The results showed that the visual wulst has a significant, most likely facilitatory, influence on the processing of contralateral visual information in the ectostriatum. Ipsilateral stimulus processing was partly independent from visual wulst activity. A model for thalamo- and tectofugal connectivity in the ectostriatum is suggested

The Dilemmas of Flexibilisation of Vocational Education and Training: A Case Study of the Piano Makers

Context: Dual VET systems are often praised for their labour market proximity because of economic stakeholders’ involvement. However, when labour market requirements change rapidly, a lack of flexibility is attributed to them. This occurs in times of fast socio-technological change like the current digital transformation. A repeatedly proposed measure to increase system flexibility is to reduce the number of occupations and create broader occupational profiles, for example, by combining similar occupations into so-called occupational fields. However, little is known about actually establishing occupational fields.Approach: Against this backdrop, we address the following research question: How was an occupational field created? As Switzerland attempted to merge occupations over a decade ago, we selected an information-rich and illuminative case concerning the research question: The piano makers’ occupation as one of the first occupations required to merge into an occupational field called musical instrument makers together with organ builders and wind instrument makers. Based on a qualitative case study, we reconstruct the process of occupational field construction by combining expert interviews with comprehensive document analysis and present its narrative.Findings: Based on this case study, we contribute to the understanding of VET flexibilisation by detailing occupational field creation and identifying opportunities and challenges. Here, we pay special attention to the institutional work of the affected occupational association and identify the importance of preserving its collective occupational identity. Although regulatory changes disrupted the piano makers’ occupation, the occupational association reinstitutionalised it as part of the musical instrument makers’ occupational field. Over a decade later, the piano makers reintroduced their former occupational title, which is deeply connected to their occupational identity. Conclusion: The results indicate that VET reforms that promote flexibilisation by creating occupational fields encounter serious limitations in collectively governed dual VET systems. In the Swiss system, occupational associations are core collective actors that rely on their members’ voluntary work. To maintain these economic stakeholders’ necessary commitment to VET, their collective occupational identity, symbolized by their long-standing occupational title, needs to be preserved.

Osmotic dependent water flow across the isolated rumen epithelium of sheep

im pdf-Format: Titelblatt, Inhaltsverzeichnis, Lebenslauf Einleitung Literatur Tabelle Material und Methoden Ergebnisse Diskussion Zusammenfassung LiteraturverzeichnisDer Pansen der Wiederkäuer bildet mit etwa 80 % den größten Teil des Vormagensystems. Trotz Speichelflusses, Futter- und Wasseraufnahme und bakterieller Fermentation im Pansen bleiben das Pansenflüssigkeits-volumen, die Elektrolytzusammensetzung und der osmotische Druck des Panseninhaltes in verhältnismäßig engen Grenzen konstant. Der osmotische Druck im Pansen von Schafen und Rindern kann jedoch zwei bis drei Stunden nach der Fütterung Extremwerte von über 400 mosmol · kg-1 erreichen. Von Schafen und Rindern ist bekannt, daß ein osmotischer Gradient im Pansen effektive Wasserbe-wegungen durch das Pansenepithel induziert. Zur näheren Charakterisierung der Wasserbe- wegungen am Pansenepithel des Schafes wurden in vitro Untersuchungen durchgeführt, die die in vivo Situation simulierten. Dabei wurde eine modifizierte Ussingkammertechnik zur direkten quantitativen Wassertransport- messung genutzt. Es wurde der (Netto)Wasser-transport in Abhängigkeit von einem trans-epithelialen osmotischen Gradienten bestimmt (mukosal 225 bis 450 mosmol·l-1, serosal immer 300 mosmol·l-1). Die Veränderungen des osmotischen Druckes erfolgte durch Mannit oder durch ein Gemisch der Kaliumsalze der flüchtigen Fettsäuren (VFA). Um einen Einfluß der Fütterung auf den Wasser- transport feststellen zu können, wurden zwei Tiergruppen untersucht. Die eine Gruppe erhielt nur Heu, die andere Gruppe zusätz-lich zum Heu 800 Gramm Kraftfutter pro Tag über drei Wochen. Folgende Resultate wurden erhalten: 1\. Der Wassertransport der Epithelien beider Fütterungsgruppen folgte linear dem osmot-ischen Gradienten. Im hypotonen Bereich wurde eine Resorption aus und im hypertonen Bereich eine Sekretion in den Pansen beobachtet. Der Wassertransport sistierte bei einem luminalen osmotischen Druck von 300 bis 311 mosmol·l-1. 2\. Bei der Verwendung von Mannit zeigten die Epithelien beider Fütterungsgruppen keinen signifikanten Unterschied in den Wassertrans- portraten. 3\. Bei der Verwendung von Kaliumsalzen der VFA wiesen die Epithelien der kraftfutter-gefütterten Schafe gegenüber den Epithelien der heugefütterten Schafe einen signifikant geringeren Wassertransport auf. Es ist sehr wahrscheinlich, daß dieser Effekt durch einen verringerten Reflexionskoeffizienten für Kalium und die VFA bedingt wird. 4\. Die Veränderungen des osmotischen Druckes der luminalen Pufferlösung verursachten Veränderungen der transepithelialen Potentialdifferenz, PDt. Mannit bedingte insbesondere im hypertonen Bereich eine Abnahme der PDt, die Kaliumsalze der VFA in allen Fällen einen Anstieg der PDt.In ruminants the rumen constitutes about 80 % of the forestomach system. In spite of flow of saliva, feed and water intake and bacterial fermentation, the volume of the rumen fluid, the concentration of the electrolytes and the osmotic pressure of the rumen content are kept within fairly close limits. However, the osmotic pressure in the rumen can reach more than 400 mosmol·kg-1 two to three hours after feeding. It is generally accepted that in sheep and cows the osmotic gradient in the rumen induces an effective flow of water through the rumen epithelium. In order to characterize the water movement through the epithelium of the rumen in sheep in vitro experiments were conducted. They simulated in vivo conditions. A modified Ussing-chamber technique was used for direct measurement of water flux. The net water flux was determined as it depended on the trans-epithelial osmotic gradient (the osmotic pressure being between 225 and 450mosmol·l-1 on the mucosal side, and 300 mosmol l-1 on the serosal side). The modification of the osmotic pressure was obtained by adding mannitol or a mixture of the potassium salts of the volatile fatty acids. In order to detect whether the feeding regime has an influence on the water flow, two groups of animals were examined. The sheep were fed with hay ad libitum (group 1) or with hay and 800 grams of concentrate (group 2). The following results were obtained: 1\. There was a linear dependency between the osmotic pressure and the water transport through the epithelia in both groups. Under hypoosmotic conditions an absorption of water from the rumen was observed. Under hyperosmotic conditions water flowed into the rumen. The water flux ceased at an osmotic pressure of 300 to 311 mosmol·l-1. 2\. The epithelia of both groups showed no significant difference in their water transport rates when mannitol was used. 3.The epithelia of the concentrate fed animals showed a significantly lower transepithelial water transport rate compared to the hay fed animals, when the potassium salts of the volatile fatty acids were used. This was probably caused by a lower reflection coefficient of potassium and the volatile fatty acids. 4\. The variation in the osmotic pressure in the ruminal fluid caused changes in the transepithelial potential difference (PDt). Especially under hypertonic conditions mannitol caused a decline of the PDt. When the potassium salts of the volatile fatty acids were used there was an increase in the PDt in all cases

Movimento social

Orientador: Ângela Massumi KatutaMonografia (especialização) - Universidade Federal do Paraná, Especialização em Educação do CampoInclui referênciasResumo: Este artigo visa trazer reflexões sobre propostas de educação aplicada no MST (Movimento dos Trabalhadores Rurais Sem Terra) e seus interesses. A Educação do Campo permite nos fazer tais questionamentos para termos uma visão mais consciente, partindo dos sujeitos frente ao movimento social, que luta por uma educação igualitária, seja ela mo campo ou cidade. A Educação do rural passa a ser questionada a partir dos anos 80, do século XX, muitos movimentos sociais passam a defender e construir elementos reflexivos sobre a educação do campo que hoje se torna foco de pesquisa para vários segmentos. Isso porque sua estrutura como formadora de políticas para os sujeitos do campo possibilita que os mesmos reconstruam sua identidade em uma perspectiva de assegurar os seus direitos como cidadãos sociais e políticos. Muitos autores apontam para a dicotomia educacional, mostrando a crescente onda de preconceitos sobre os educando do campo. A quem devemos culpar se o movimento para educação dentro do MST gera essa diferença de opinião, pois se o agente organizador é o Estado? Também não podemos esquecer que a educação é um dos pontos primordiais do MST, onde seus agentes se preocupam com uma formação adequada para a compreensão da sua realidade, mas reinvidicando uma educação diferenciada daquela da cidad