Hendrick Ladich to Peter Van Brugh Livingston, April 5, 1746

Hendrick wrote in Dutch to Peter, address: New York. The verso says May 8, 1746, H. Ladich & Cap. Kip answered.https://digitalcommons.kean.edu/lhc_1740s/1002/thumbnail.jp

Auditory evoked potential audiometry in fish

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Reviews in Fish Biology and Fisheries 23 (2013): 317-364, doi:10.1007/s11160-012-9297-z.A recent survey lists more than 100 papers utilizing the auditory evoked potential (AEP) recording technique for studying hearing in fishes. More than 95 % of these AEP-studies were published after Kenyon et al. introduced a non-invasive electrophysiological approach in 1998 allowing rapid evaluation of hearing and repeated testing of animals. First, our review compares AEP hearing thresholds to behaviorally gained thresholds. Second, baseline hearing abilities are described and compared in 111 fish species out of 51 families. Following this, studies investigating the functional significance of various accessory hearing structures (Weberian ossicles, swim bladder, otic bladders) by eliminating these morphological structures in various ways are dealt with. Furthermore, studies on the ontogenetic development of hearing are summarized. The AEP-technique was frequently used to study the effects of high sound/noise levels on hearing in particular by measuring the temporary threshold shifts after exposure to various noise types (white noise, pure tones and anthropogenic noises). In addition, the hearing thresholds were determined in the presence of noise (white, ambient, ship noise) in several studies, a phenomenon termed masking. Various ecological (e.g., temperature, cave dwelling), genetic (e.g., albinism), methodical (e.g., ototoxic drugs, threshold criteria, speaker choice) and behavioral (e.g., dominance, reproductive status) factors potentially influencing hearing were investigated. Finally, the technique was successfully utilized to study acoustic communication by comparing hearing curves with sound spectra either under quiet conditions or in the presence of noise, by analyzing the temporal resolution ability of the auditory system and the detection of temporal, spectral and amplitude characteristics of conspecific vocalizations.Support from the Austrian Science Fund (FWF grant 22319 to F.L.)

Effects of Temperature on Sound Production and Auditory Abilities in the Striped Raphael Catfish Platydoras armatulus (Family Doradidae)

Background: Sound production and hearing sensitivity of ectothermic animals are affected by the ambient temperature. This is the first study investigating the influence of temperature on both sound production and on hearing abilities in a fish species, namely the neotropical Striped Raphael catfish Platydoras armatulus. Methodology/Principal Findings: Doradid catfishes produce stridulation sounds by rubbing the pectoral spines in the shoulder girdle and drumming sounds by an elastic spring mechanism which vibrates the swimbladder. Eight fish were acclimated for at least three weeks to 22 degrees, then to 30 degrees and again to 22 degrees C. Sounds were recorded in distress situations when fish were hand-held. The stridulation sounds became shorter at the higher temperature, whereas pulse number, maximum pulse period and sound pressure level did not change with temperature. The dominant frequency increased when the temperature was raised to 30 degrees C and the minimum pulse period became longer when the temperature decreased again. The fundamental frequency of drumming sounds increased at the higher temperature. Using the auditory evoked potential (AEP) recording technique, the hearing thresholds were tested at six different frequencies from 0.1 to 4 kHz. The temporal resolution was determined by analyzing the minimum resolvable click period (0.3-5 ms). The hearing sensitivity was higher at the higher temperature and differences were more pronounced at higher frequencies. In general, latencies of AEPs in response to single clicks became shorter at the higher temperature, whereas temporal resolution in response to double-clicks did not change

Erzwungene Komplizenschaft: Bruchstücke zu einer literarischen Ethnographie des Internats bei Tobias Wolff und Kazuo Ishiguro

'Im Anschluss an eine Debatte der neueren Gewaltsoziologie, welche die Erforschung auch jener gewaltförmiger Sozialbeziehungen anmahnt, die ohne den Einsatz physischer Gewalt auskommen, nimmt der Text Internate aus einer machtkritischen Perspektive in den Blick. Am Beispiel zweier Romane sowie instrumentiert durch Pierre Bourdieus Konzept symbolischer Gewalt sucht der Beitrag einen Einblick in Abhängigkeitsverhältnisse zu verschaffen, in die Internate die ihnen Anvertrauten mitunter verstricken. Auf diese Weise soll es nicht nur gelingen, für die weichen Mechanismen des Ausschlusses zu sensibilisieren, die bei der Erforschung der Reproduktion sozialer Ungleichheit häufig vernachlässigt werden, sondern auch ein Sensorium für die pädagogischen Spielarten symbolischer Gewaltverhältnisse auszubilden und einen Zugang zu deren Erleben zu verschaffen.' (Autorenreferat)'Taking up an ongoing discussion, in the field of the sociology of violence, which stresses the need for research on such forms of social coercion as are effected without physical violence, boarding schools are approached in a perspective of a criticism of power. Focusing on two novels and relying on Pierre Bourdieu's concept of symbolic violence, the paper aims to shed light on the relations of dependency students of boarding schools may get entrapped in. This may not only enhance current sensitivity for the soft mechanisms of exclusion which research in social inequality tends to neglect, but may also alert researchers to the pedagogical varieties of symbolic violence and provide an approach to how these are lived.' (author's abstract)

A unique swim bladder-inner ear connection in a teleost fish revealed by a combined high-resolution microtomographic and three-dimensional histological study

Background: In most modern bony fishes (teleosts) hearing improvement is often correlated with a close morphological relationship between the swim bladder or other gas-filled cavities and the saccule or more rarely with the utricle. A connection of an accessory hearing structure to the third end organ, the lagena, has not yet been reported. A recent study in the Asian cichlid Etroplus maculatus provided the first evidence that a swim bladder may come close to the lagena. Our study was designed to uncover the swim bladder-inner ear relationship in this species. We used a new approach by applying a combination of two high-resolution techniques, namely microtomographic (microCT) imaging and histological serial semithin sectioning, providing the basis for subsequent three-dimensional reconstructions. Prior to the morphological study, we additionally measured auditory evoked potentials at four frequencies (0.5, 1, 2, 3 kHz) to test the hearing abilities of the fish. Results: E. maculatus revealed a complex swim bladder-inner ear connection in which a bipartite swim bladder extension contacts the upper as well as the lower parts of each inner ear, a condition not observed in any other teleost species studied so far. The gas-filled part of the extension is connected to the lagena via a thin bony lamella and is firmly attached to this bony lamella with connective material. The second part of the extension, a pad-like structure, approaches the posterior and horizontal semicircular canals and a recessus located posterior to the utricle. Conclusions: Our study is the first detailed report of a link between the swim bladder and the lagena in a teleost species. We suggest that the lagena has an auditory function in this species because the most intimate contact exists between the swim bladder and this end organ. The specialized attachment of the saccule to the cranial bone and the close proximity of the swim bladder extension to the recessus located posterior to the utricle indicate that the saccule and the utricle also receive parallel inputs from the swim bladder extension. We further showed that a combination of non-destructive microCT imaging with histological analyses on the same specimen provides a powerful tool to decipher and interpret fine structures and to compensate for methodological artifacts

Abstieg vom Feldherrenhügel: Zum Ort kritischer Theoriebildung

Abstieg vom Feldherrenhügel: Zum Ort kritischer Theoriebildun