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The oldest representative of a modern deep-sea ophiacanthid brittle-star clade from Jurassic shallow-water coral reef sediments
No full textOphiurites crinitus is a fossil brittle−star species which passed largely unnoticed since its original description. In this paper, we redescribe the type material of O. crinitus with the aim to put it into the context of modern ophiuroid systematics, and propose the new genus name Ophiosternle to replace the invalid Ophiurites. The re−assessed species is shown to be a member of the extant deep−sea family Ophiacanthidae, articulated fossils of which are extremely rare. It presents greatest affinities with members of the Ophioplinthaca–Ophiocamax–Ophiomitra clade, of which it most probably represents the oldest known fossil species. The depositional environment of the strata, which yielded the described specimens is interpreted as shallow, storm−influenced marine setting in the immediate vicinity of coral reefs. This contrasts with the distribution pattern of extant species of the Ophioplinthaca–Ophiocamax–Ophiomitra clade, which almost exclusively occur at depths exceeding the shelf break
When sleep is perceived as wakefulness: an experimental study on state perception during physiological sleep
No full textWhile electrophysiologically measured sleep and perception of sleep generally concur, various studies have shown this is not always the case. The objective of the present study was to assess the perception of actual state during sleep by the technique of planned awakenings and interviewing subjects on the preawakening state. Sixty-eight (43 females, 25 males) young (mean age: 24.1, SD 5.1 years) normal sleeping subjects were deliberately awakened out of consolidated sleep, either stage 2 (S2), or REM sleep, during the first night in a non-clinical sleep laboratory. While the preawakening state was experienced as sleep in 48 cases (70.6%), it was experienced as wakefulness in 20 cases (29.4%). The percentage of awake judgements was somewhat, but not significantly, higher for awakenings out of S2 (38.2%), to REM sleep (20.6%). The proportion of mismatches between electrophysiologically defined sleep and state judgements was time-dependent with more awake judgements for REM sleep in the second half of the sleep period (41.7%) than in the first one (17.4%). Those subjects who made an awake judgement more frequently had a feeling of being aware of the situation and their surroundings than those who made a sleep judgement (80% versus 33%). Awareness during sleep may be a cognitive style, which favours mismatches between state perception and electrophysiologically defined sleep. Sleep periods with concordant or discordant state judgements did not differ in electrophysiologically defined sleep onset latency, sleep efficiency, or sleep state distribution
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Monsoon-driven changes in aeolian and fluvial sediment input to the central Red Sea recorded throughout the last 200,000 years
No full textClimatic and associated hydrological changes controlled the transport processes and composition of the sediments in the central Red Sea during the last ca. 200 kyr. Three different source areas for mineral dust are identified. The dominant source is located in the eastern Sahara (Sudan and southernmost Egypt). We identify its imprint on Red Sea sediments by high smectite and Ti contents, high 87Sr/86Sr and low εNd. The availability of deflatable sediments was controlled by the intensity of tropical rainfall and vegetation cover over northern Africa linked to the African monsoon. Intense dust input to the Red Sea occurred during arid phases, low input during humid phases. A second, less significant source indicated by palygorskite input is probably located on the eastern Arabian Peninsula and/or Mesopotamia, while the presence of kaolinite suggests an additional minor dust source in northern Egypt. Our grain size data reflect episodes of fluvial sediment discharge to the central Red Sea and document the variable strength in response to all of the precession-paced insolation maxima during our study interval including both those that were strong enough to trigger sapropel formation in the eastern Mediterranean Sea and those that were not. The African Humid Period most strongly expressed in our Red Sea record was the one during the Eemian last interglacial at ca. 125 ka, followed by those at 198 ka, 108 ka, 84 ka and 6 ka
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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