4,596 research outputs found
Newbold stair tower
No full textThis black-and-white photograph presents a top-down view of a spiral staircase. At the center hangs a chandelier. The staircase curves around the chandelier. The label accompanying the photograph reads,"Newbold Stair Tower (Meigs, An American Country House, 1925, p. 41
Steam Engine Leader at Hinkley
No full textGarrett showman's steam tractor No.33987 'Leader', registration 'BJ5597' (built 1920). 'P. W. Barlow' on canopy. Photographed at Hinkley, 1971
Corner and sloped culvert baffles improve the upstream passage of adult European eels (Anguilla anguilla)
No full textInstallation of baffles intended to improve fish passage through culverts can reduce discharge capacity and trap debris, increasing flood risk. A sloping upstream face may reduce this risk, but new designs must be tested for fish passage efficiency. The European eel (Anguilla anguilla) is a critically endangered species, yet the suitability of even common baffle types to aid upstream movement has not been tested. This study compared the water depth, velocity, turbulent kinetic energy (TKE), and upstream passage performance of adult yellow-phase eels, between three 6 m long culvert models: smooth and unmodified (control); containing corner baffles (treatment 1); and with prototype sloped baffles installed (treatment 2). Passage of individual fish was assessed during 25 one-hour trials per model. Performance was quantified as entrance efficiency, number of entries per fish, passage efficiency, and overall efficiency. Total and passage delay, and successful passage time were also evaluated. Despite some individuals being able to swim against unexpectedly high water velocities (>1.5 m s?1 for 4 m), passage performance in the control was poor, with an overall efficiency of 28%. Compared to the control, both treatments increased the mean centreline water depth by approximately 0.11 m, created heterogeneous flow conditions with low velocity resting areas, and reduced maximum velocities. As a result, entrance rate and all efficiency parameters were higher for the treatments than for the control (overall efficiency = 84%), despite longer passage delay. The TKE was slightly higher in treatment 2 than 1, but there was no difference in water depth or overall efficiency. The findings show that both corner and sloped baffles can mitigate for impeded upstream adult eel movement. The extent to which the sloping upstream face will improve debris transport should be explored further
A well-conserved Plasmodium falciparum var gene shows an unusual stage-specific transcript pattern
No full textThe var multicopy gene family encodes Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variant antigens, which, through their ability to adhere to a variety of host receptors, are thought to be important virulence factors. The predominant expression of a single cytoadherent PfEMP1 type on an infected red blood cell, and the switching between different PfEMP1 types to evade host protective antibody responses, are processes thought to be controlled at the transcriptional level. Contradictory data have been published on the timing of var gene transcription. Reverse transcription-polymerase chain reaction (RT-PCR) data suggested that transcription of the predominant var gene occurs in the later (pigmented trophozoite) stages, whereas Northern blot data indicated such transcripts only in early (ring) stages. We investigated this discrepancy by Northern blot, with probes covering a diverse var gene repertoire. We confirm that almost all var transcript types were detected only in ring stages. However, one type, the well-conserved varCSA transcript, was present constitutively in different laboratory parasites and does not appear to undergo antigenic variation. Although varCSA has been shown to encode a chondroitin sulphate A (CSA)-binding PfEMP1, we find that the presence of full-length varCSA transcripts does not correlate with the CSA-binding phenotype
Plasmodium vevax and P. falciparum: Biological interactions and the possibility of cross-species immunity.
No full textThe question of whether infection of humans with one species of malaria parasite alters the course of infection with another has been largely ignored because no such interaction was found during studies of induced malaria in patients with neurosyphilis. However, in animal model systems some degree of cross-species interaction is the rule rather than the exception. Furthermore, recent epidemiological observations in Vanuatu in the South Pacific have suggested a biological interaction between the dominant species, Plasmodium vivax, and P. falciparum. Kathryn Maitland, Tom Williams and Chris Newbold here speculate on the basis of these observations and other published findings that infection with P. vivax may result in the development of immunity sufficient to ameliorate the clinical course of subsequent infections with the potentially lethal parasite P. falciparum
Framing the Framework: Four Decades of Change in Language Teaching (and the Long March of ELF)
No full textIn this paper I reflect on changes in language use over more than four decades, which have prompted a revised (2018) version of the Common European Framework, the ‘Companion Volume’. The appearance of the Council of Europe’s ‘threshold level’ in 1976, later to take its place as B1 in the six-level CEFR, heralded a new attention to communication for language teaching professionals. The age of audio-lingualism was past, giving way to the communicative revolution, and its attention to ‘real language’, and ‘authentic materials’.
In the revised Framework this approach has shifted to reflect changes in lifestyles and technological progress in the new millennium. No longer is the focus on preparing learners to communicate with native speakers, but on plurilingualism and inclusion; the single scale of descriptors for phonology has been replaced by three scales, none of which refer to proximity to a native speaker accent; and, perhaps most significantly, there are completely new scales for online interaction. I shall take a critical look at these changes and their implications for teachers: four decades of change which have provided the backdrop to Carmel’s career at the forefront of language teaching research
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