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In the isolated rat liver perfused in situ stimulation of the nerve bundles around the portal vein and the hepatic artery caused an increase of urate formation that was inhibited by the α1-blocker prazosine and the xanthine oxidase inhibitor allopurinol. Moreover, nerve stimulation increased glucose and lactate output and decreased perfusion flow. Infusion of noradrenaline had similar effects. Compared to nerve stimulation infusion of glucagon led to a less pronounced increase of urate formation and a twice as large increase in glucose output but a decrease in lactate release without affecting the flow rate. Insulin had no effect on any of the parameters studied.
Content: 1 Introduction 2 Theoretical background - Expertise and Reserve Capacity - Testing-the-Limits and Research on Expertise - Cognitive Processes and Knowledge - Age Comparisons of Peak Performance - Advantages of Constructed Versus Naturally Acquired Expertise - Hypotheses Related to Aging and Expertise: Toward Magnification and Identification of Age Differences and Aging-Sensitive Components 3 Theory-guided synthesis of memory expertise - Theoretical Framework - Procedure - Subjects - Results 4 Adaptivity testing of expert memory - Increasing Task Difficulty Within an Extant System - Selective Componential Interference - Toward the Study of Compensatory Processes 5 Conclusions
This article outlines a research strategy for investigating, in a laboratory setting, the acquisition and the "limits" of a cognitive skill. Expert digit memory is used as an illustration. Two participants with initial average digit- and word-span memory were trained to memorize and reproduce strings of 80 to 90 digits presented at 10- to 1-sec rates. The instruction and training program, based on a theory of skilled memory, focused on three components: (a) acquisition of a mnemonic system (i.e., recoding digits into historical dates or concrete nouns), (b) use of a long-term memory retrieval structure (i.e., instruction in the Method of Loci), and (c) improvement in processing speed. After 86 experimental sessions, one participant recalled 90 random digits presented at a 1-sec rate. The digits were, however, constrained to be compatible with the participant's historical knowledge. The second participant recalled 80 random digits presented at a 5-sec rate after 70 sessions. Speed of encoding and retrieval processing was the only component that required extensive practice for skilled digit-memory acquisition.
Wenn man fragt, unter welchen gesellschaftlichen Bedingungen Eheleute und Geliebte sich heute zurechtfinden müssen, kann man an drei auffälligen Entwicklungen nicht vorbeisehen: erstens an der zunehmenden Integration der Mittelschicht-Frauen in den Arbeitsmarkt, zweitens an der Randposition der Männer in der modernen Familie und drittens an der Zunahme der Scheidungszahlen. Es handelt sich um drei Bedingungen, mit denen Ehen und andere Liebesbeziehungen heute konfrontiert sind. Ich überlege in meinem Aufsatz, was sie insbesondere für die Rolle der Geliebten bedeuten.
Los niños tienen secretos: secretos para sí solos o secretos que comparten con otros; lenguajes secretos, escrituras secretas y signos distintivos secretos. Nosotros recordamos una fase de nuestra época escolar en que la mayor parte de las noticias entre amigos eran tratadas como algo secreto, que no debía ser comunicado a personas extrañas - era la edad entre los 11 y los 13 años, cuando se formaron en el aulas aquellas agrupaciones que luego se mantuvieron casi inalterables hasta el bachillerato: ¿ los secretos y el secreto como elementos de la «socialización consciente»? Ya en las clases escolares, escribe G. SlMMEL, se hace perceptible cómo los círculos de amigos, por el simple hecho formal de constituir un grupo particular, se conciben como una élite frente a lo no organizado y cuya superioridad los otros también reconocen por la envidia y recelo que suscitan (1958. 296). Por eso también era irrelevante el contenido del respectivo «secreto», no bien aparecía uno: sólo cuchicheaban entre ellos y hacían como que tuvieran que conversar algo, a fin de fortalecer el sentido de compañerismo y para delimitarse frente a los demás, que entonces mostraban curiosidad y recién de esa manera habían de ser rechazados.
The optical density of human macular pigment was measured for 50 observers ranging in age from 10 to 90 years. The psychophysical method required adjusting the radiance of a 1°, monochromatic light (400–550 nm) to minimize flicker (15 Hz) when presented in counterphase with a 460 nm standard. This test stimulus was presented superimposed on a broad-band, short-wave background. Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5° temporally. This difference spectrum, measured for 12 observers, matched Wyszecki and Stiles's standard density spectrum for macular pigment. To study variation in macular pigment density for a larger group of observers, measurements were made at only selected spectral points (460, 500 and 550 nm). The mean optical density at 460 nm for the complete sample of 50 subjects was 0.39. Substantial individual differences in density were found (ca. 0.10–0.80), but this variation was not systematically related to age.
The inhibitory effect of sinefungin on juvenile hormone biosynthesis and development in locusts
(1987)
The antibiotic fungal metabolite sinefungin is a potent inhibitor of S-adenosylmethionine-acceptor methyltransferases. Its effect on insect metabolism and especially on corpora allata farnesoic acid methyltransferase, which catalyzes the penultimate step of juvenile hormone biosynthesis, was investigated in Locusta migratoria. Injection of sinefungin results in a delay of imaginal molt and in suppression of ovary development. Isolated corpora allata are unable to synthesize juvenile hormone III in the presence of more than 1.0 mM sinefungin. In a cell-free system containing the S-adenosylmethionine-dependent farnesoic acid methyltransferase from corpora allata sinefungin is a competitive inhibitor of the synthesis of methylfarnesoate with Ki of 1 μM.
Sequences from natural conversations, which are in ethnomethodological conversational analysis analyzed as "other-initiated self-repair", are here described as sequences in which participants manifest and treat local problems of understanding. This approach, which takes participants' perspectives into account, shows that these sequences have a detailed internal structure: - Participants use different types of problem manifestation to signal different types of problems of understanding; syntactic and prosodic cues are used as type-differentiating devices in problem manifestation; for different types of problems different assumptions with respect to the degree of reciprocity can be reconstructed as underlying problem manifestation and problem treatment. - There is a relation of conditional relevance holding between specific types of problem manifestation and specific types of problem treatment. - Problem types are ordered in relation to each other in terms of preference structures. Thus, an analysis which takes participants' perspectives into account and which looks more closely at linguistic signalling cues allows to differentiate between various types of internal structures within so-called repair sequences.
Auszug: Die Geschichte der Prophetie im Judentum oder in Israel ist so alt und vielgestaltig wie die israelitisch-jüdische Kultur selbst.Eine Geschichte der jüdischen Prophetie ist zugleich eine Geschichte der jüdischen Theologie, jede Zeit hatte ihre eigenen Vorstellungen vom Wesen und Auftrag der Propheten. Konstant geblieben ist jedoch das Bedürfnis der Menschen nach Männern (und Frauen), die einen direkten und unvermittelten Kontakt zur Gottheit haben, um ihren Zeitgenossen mit Autorität den Willen Gottes mitteilen zu können. Alleine so ist es verständlich, warum den dezidierten Äußerungen vieler talmudischer Gelehrter vom Ende der Prophetie kein dauerhafter Erfolg beschieden war - trotz des kanonischen Ansehens des Talmud bei den späteren Generationen.Denn "die Zerstörung des ersten Tempels ist nach Auffassung vieler Rabbinen der Zeitpunkt, an dem der heilige Geist sich von Israel entfernte. [...]
Motivational conditions have been thus far largely neglected by contemporary theoretical approaches in knowledge psychology. The present article attempts to demonstrate the necessity for the greater integration of both. Suggestions are made regarding the choice and conceptualization of relevant motivational factors. Two possible groups of factors can be distinguished: (1) motivational factors of personality, and (2) motivational effects of action. Available theoretical approaches (e.g., the "levels of processing" approach) and examples are used to clarify the potential effects of these factors on the acquisition and representation of knowledge. Finally, a review is made of empirical studies allowing confirmatory allegations about the posited relationships between motivational factors and processes related to knowledge. This review reveals substantial research deficits on this topic.