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Acquisition of academic literacy is often a difficult process for students, and in South Africa this is compounded by the fact that education for most secondary school pupils takes place in a second language at under-resourced schools. This article describes the scaffolding of an academic literacy course designed for South African students from such schools, who enter science study through alternative access routes. An approach to selecting and rewriting texts as well as scaffolding methods for reading and writing are described and illustrated with examples. Since our entrants have had limited prior exposure to text and academic writing, an academic literacy course is needed in which texts are level-appropriate, and reading instruction is scaffolded. Writing instruction, in which students are supported by means of extensive tutor response to drafts, focuses on pedagogically important genres in science, particularly the laboratory report and essay.

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Introduction Immunosenescence, a decline in immune system function, has been linked to several age-related diseases and geriatric syndromes, including cardiovascular diseases and frailty. Very old adults (aged ≥85 years) live with multiple long-term conditions (MLTC) or multimorbidity—a complex phenomenon of poor health defined by either counts (≥2 diseases), indices, or patterns. However, little is known about the relationship between immunosenescence and MLTC in this age group. We utilised baseline data from the Newcastle 85+ Study to investigate the association between previously defined immunosenescence profilesa and MLTC. Method We used data from 703 participants who had multimorbidity and complete data for 16 chronic diseases and geriatric syndromes (i.e. analytic sample). MLTC counts were derived from the number of conditions and categorised into

Many adult traits in Drosophila melanogaster show phenotypic plasticity, and the effects of diet on traits such as lifespan and reproduction are well explored. Although plasticity in response to food is still present in older flies, it is unknown how sustained environmental variation affects life-history traits. Here, we explore how such life-long fluctuations of food supply affect weight and survival in groups of flies and affect weight, survival and reproduction in individual flies. In both experiments, we kept adults on constant high or low food and compared these to flies that experienced fluctuations of food either once or twice a week. For these 'yoyo' groups, the initial food level and the duration of the dietary variation differed during adulthood, creating four 'yoyo' fly groups. In groups of flies, survival and weight were affected by adult food. However, for individuals, survival and reproduction, but not weight, were affected by adult food, indicating that single and group housing of female flies affects life-history trajectories. Remarkably, both the manner and extent to which life-history traits varied in relation to food depended on whether flies initially experienced high or low food after eclosion. We therefore conclude that the expression of life-history traits in adult life is affected not only by adult plasticity, but also by early adult life experiences. This is an important but often overlooked factor in studies of life-history evolution and may explain variation in life-history experiments. [ABSTRACT FROM AUTHOR]

Presents a report on `The Medical Research Council/ Research into Ageing Workshop' held on 6 October 1993. Brief accounts of works of several scientists, presented in the conference.

Recent studies in mice have highlighted the importance of polymorphic genetic loci such as the major histocompatibility complex (MHC) or minor lymphocyte-stimulating antigen (Mls) in determining the nature of the peripheral T-cell receptor (TcR) population.' 'As our knowledge of the equivalent process in humans is incomplete, we have utilized a modification of the polymerase chain reaction (PCR)4 6 to determine the overall genetic contribution to the normal human TcR variable Vβ gene repertoire. These data demonstrate that the normal human T-cell population contains members of all the major TcR Vβ families and that thee is considerable variation in the relative amounts of specific TcR Vβ transcripts between individuals. We have established that the normal peripheral TcR Vβ repertoire is more concordant in identical twins than in unrelated individuals. The relative importance of genetic factors in determining the peripheral TcR repertoire is emphasized by these results and suggests that, in humans, the genetic control of immune responsiveness is mediated in part by the peripheral TcR repertoire. [ABSTRACT FROM AUTHOR]

A total of 233 primary alloreactive T-cell clones have been tested for the production of interleukin-2 (IL-2), interleukin-3 (IL-3), immune (gamma) interferon (IFN) and granulocyte-macrophage colony-stimulating factor (CSF-2), S-cell growth factor I and II (SCGFI, BCGFII), and eosinophil differentiation factor (EDF). EDF was assayed by means of the eosinophil differentiation assay (EDA). Two principal correlations were observed: IL-3 was shown to be the major lymphokine detected in the bone marrow proliferation assay (BMPA) used to detect CSF-2, and there was a high correlation between the EDA and SCGFII. Subsequent work has suggested that this latter correlation is because a single factor is responsible for both activities. Apart from these two exceptions, and low level correlations probably due to the fact that different assays detect more than one lymphokine, there was no evidence for co-ordinate expression of lymphokines. There was a large variation in amounts of individual lymphokines produced. More clones produced multiple lymphokines than would be expects from independent control. Taken together, this pattern of regulation is consistent with the hypothesis that antigen stimulation of T cells results in the activation of all the lymphokine genes, but the amount of each produced is determined by secondary controlling mechanisms. [ABSTRACT FROM AUTHOR]

A collaborative study involving nine independent assays by eight laboratories has recalibrated the anti-D concentration of the International Reference Preparation of Anti-D Immunoglobulin (68/417) in terms of the International Standard for Anti-Rho (anti-D) Incomplete Blood Typing Serum (64/16). This study was carried out when it was found that 68/419 had been calibrated not against 64/16, as originally intended, but inadvertently against another preparation. Based on the results, a revised rounded off value of 300 IU anti-D per ampoule of 68/419 was assigned by the Expert Committee on Biological Standardisation of WHO at its 30th meeting. Many of the known variables in anti-D quantitation using the AutoAnalyzer were considered in the preparation of the protocol for this study. The remarkably close agreement of the results indicated that the format can be used as an acceptable model for interlaboratory studies in the future. [ABSTRACT FROM PUBLISHER]

This paper announces the availability of the first international standard for anti-double-stranded DNA (anti-dsDNA). The material, coded Wo/80, was obtained after recalcification of plasma taken from a patient with systemic lupus erythematosus. Vials were filled with 500 microliters serum and freeze dried. The serum contains no other autoantibodies in measurable quantities. The vials should be stored at -20 degrees C. The standard should be used for establishing national, regional, or local standards. In eight laboratories satisfactory results with the immunofluorescence technique on Crithidia luciliae were obtained; the titres varied between 1/20 and 1/640 (mean 1/160). In seven laboratories the Farr assay, with the so called 'Amersham kit', was performed. At a dilution of 1:40 a mean binding percentage of about 50% was observed. After reconstitution with 500 microliters of distilled water, the vial contains 100 IU/500 microliters or 200 IU/ml. The standard can be obtained from the custodian of WHO: Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, PO Box 9190 1006 AD Amsterdam, The Netherlands. [ABSTRACT FROM PUBLISHER]