7,629 research outputs found

    Permian trace fossils attributed to tetrapods (Tierberg Formation, Karoo Basin, South Africa)

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    The discovery of a paving slab with a number of prints suggestive of footprints of tetrapods led to a reinvestigation of a trace fossil, known from three localities, of which only two photographs had been published, each with only four prints. The slab was traced to a previously unrecorded site, De Puts, near Calvinia, located in the Tierberg Formation of the Ecca Group of the Karoo Supergroup. The prints from all the sites are referred to Broomichnium permianum Kuhn 1958, of which Quadrispinichna parvia of Anderson 1974 is a synonym.Palaeo-Anthropology Scientific Trust; French Embassy in South Africa; Co-operation and Cultural Servic

    Biperiodic superlattices and the transparent state

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    Coquelin et al. studied biperiodic semiconductor superlattices, which consist of alternating cell types, one with wide wells and the other narrow wells, separated by equal strength barriers. If the wells were identical, it would be a simply periodic system of N=2nN = 2n half-cells. When asymmetry is introduced, an allowed band splits at the Bragg point into two disjoint allowed bands. The Bragg resonance turns into a transparent state located close to the band edge of the lower(upper) band when the first(second) well is the wider. Analysis of this system gives insight into how band splitting occurs. Further we consider semi-periodic systems having N=2n+1N= 2n+1 half-cells. Surprisingly these have very different transmission properties, with an envelope of maximum transmission probability that crosses the envelope of minima at the transparent point.Comment: 12 pages, 10 figures Version 2: improved figures using colour, and some small improvements in the text, in response to referee comments Version 3: incorporates changes which arose in proofs stag

    Palaeozoic insects of southern Africa: a review

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    Although a substantial number of Triassic insect fossils have been discovered in southern Africa, relatively few insect fossils are known from the Permian deposits of this region. Fossil insects from the Permian period elsewhere, including the extensive entomological fauna from Eastern Europe (including Russia), Brazil and Australia is well-documented. The Irati Formation in the Parana Basin of Brazil, the temporal and lithological correlate of the Permian Whitehill Formation of South Africa, has yielded fossil insects belonging to Homoptera, N europtera, Coleoptera and Mecoptera. Fossil insects from the Whitehill Formation are usually poorly preserved and only seven specimens are mentioned in the literature. An overview is given of the more recent discoveries of Permian fossil insects in South Africa. This includes the discovery of the oldest beetle in Africa, the oldest longhorned grasshopper in the Southern Hemisphere and a survey of the Permian insects from the Beaufort Group of Natal. Reasons for the paucity of Permian insects are briefly discussed.Palaeo-Anthropology Scientific Trust; French Embassy in South Africa; Co-operation and Cultural Servic

    Are (pre)adolescents differentially susceptible to experimentally manipulated peer acceptance and rejection? A vignette-based experiment

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    The differential susceptibility model proposes that some children are more susceptible to both positive and negative peer relationships than others. However, experimental evidence supporting such a proposition is relatively scarce. The current experiment aimed to help address this gap, investigating whether Chinese (pre)adolescents who have higher levels of general sensitivity to the environment (i.e., higher levels of sensory processing sensitivity [SPS]) would be more strongly affected by peer acceptance and rejection. (Pre)adolescents aged 8.75–15.17 (N = 1,207, Mage = 11.19 years, 59.7% boys) randomly received four hypothetical vignettes describing either peer acceptance or peer rejection. Before and after this manipulation, they reported on their positive and negative mood. We assessed (pre)adolescents’ SPS using (pre)adolescent self-reports, as well as caregiver reports for a subset of (pre)adolescents (n = 480). Results supported differential susceptibility to peer rejection and acceptance for self-reported SPS, but not caregiver-reported SPS. (Pre)adolescents with higher levels of self-reported SPS not only had stronger increases in positive mood upon peer acceptance (susceptible “for better”; ÎČ = .09, p = .001) but also stronger increases in negative mood upon peer rejection (susceptible “for worse”; ÎČ = .09, p = .023). These findings illustrate the short-term dynamics that may underlie differences in children’s long-term susceptibility to acceptance or rejection by peers

    The social cognition of medical knowledge, with special reference to childhood epilepsy

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    This paper arose out of an engagement in medical communication courses at a Gulf university. It deploys a theoretical framework derived from a (critical) sociocognitive approach to discourse analysis in order to investigate three aspects of medical discourse relating to childhood epilepsy: the cognitive processes that are entailed in relating different types of medical knowledge to their communicative context; the types of medical knowledge that are constituted in the three different text types analysed; and the relationship between these different types of medical knowledge and the discursive features of each text type. The paper argues that there is a cognitive dimension to the human experience of understanding and talking about one specialized from of medical knowledge. It recommends that texts be studied in medical communication courses not just in terms of their discrete formal features but also critically, in terms of the knowledge which they produce, transmit and reproduce

    Rhetoric in the language of real estate marketing

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    “Des. Res.”, “rarely available”, “viewing essential” – these are all part of the peculiar parlance of housing advertisements which contain a heady mix of euphemism, hyperbole and superlative. Of interest is whether the selling agent’s penchant for rhetoric is spatially uniform or whether there are variations across the urban system. We are also interested in how the use of superlatives varies over the market cycle and over the selling season. For example, are estate agents more inclined to use hyperbole when the market is buoyant or when it is flat, and does it matter whether a house is marketed in the summer or winter? This paper attempts to answer these questions by applying textual analysis to a unique dataset of 49,926 records of real estate transactions in the Strathclyde conurbation over the period 1999 to 2006. The analysis opens up a new avenue of research into the use of real estate rhetoric and its interaction with agency behaviour and market dynamics

    Somatostatin does not attenuate intestinal injury in dextran sodium sulphate-induced subacute colitis.

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    FRom several in vitro and in vivo studies involvement of somatostatin (SMS) in intestinal inflammation emerge. Acute colitis induced in rats is attenuated by the long-acting SMS analogue octreotide. We studied the potential beneficial effect of SMS on non-acute experimental colitis. BALB/c mice received either saline, SMS-14 (36 or 120 microg daily) or octreotide (3 microg daily) subcutaneously delivered by implant osmotic pumps. A non-acute colitis was induced by administration of dextran sodium sulphate (DSS) 10% in drinking water during 7 days. DSS evoked a mild, superficial pancolitis, most characterized by mucosal ulceration and submucosal influx of neutrophils. Neither SMS-14 nor octreotide reduced mucosal inflammatory score or macroscopical disease activity, although reduction of intestinal levels of interleukin-1beta (IL-1beta), IL-6 and IL-10 during DSS was augmented both by SMS and octreotide. A slight increase of neutrophil influx was seen during SMS administration in animals not exposed to DSS. In conclusion, SMS or its long-acting analogue did not reduce intestinal inflammation in non-acute DSS-induced colitis. According to the cytokine profile observed, SMS-14 and octreotide further diminished the reduction of intestinal macrophage and Th2 lymphocyte activity

    Clinical recommendations for pain, sedation, withdrawal and delirium assessment in critically ill infants and children: an ESPNIC position statement for healthcare professionals

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    Background: This position statement provides clinical recommendations for the assessment of pain, level of sedation, iatrogenic withdrawal syndrome and delirium in critically ill infants and children. Admission to a neonatal or paediatric intensive care unit (NICU, PICU) exposes a child to a series of painful and stressful events. Accurate assessment of the presence of pain and non-pain related distress (adequacy of sedation, iatrogenic withdrawal syndrome, and delirium) is essential to good clinical management and to monitoring the effectiveness of interventions to relieve or prevent pain and distress in the individual patient. Methods: A multidisciplinary group of experts was recruited from the members of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC). The group formulated clinical questions regarding assessment of pain and non-pain related distress in critically ill and non-verbal children, and searched the PubMed/Medline, Cinahl, and Embase databases for studies describing the psychometric properties of assessment instruments. Further, level of evidence of selected studies was assigned and recommendations were formulated, and grade or recommendations were added based on the level of evidence. Results: An ESPNIC Position Statement was drafted which provides clinical recommendations on assessment of pain (n=5), distress and/or level of sedation (n=4), iatrogenic withdrawal syndrome (n=3), and delirium (n=3). These recommendations were based on the available evidence and consensus amongst the experts and other members of the ESPNIC society. Conclusions: This multidisciplinary ESPNIC Position Statement guides professionals in the assessment and re-assessment of the effectiveness of treatment interventions for pain, distress, inadequate sedation, withdrawal syndrome and delirium
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