760 research outputs found

    Deriving accurate peculiar velocities (even at high redshift)

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    The way that peculiar velocities are often inferred from measurements of distances and redshifts makes an approximation, v_p = cz-H_0 D, that gives significant errors even at relatively low redshifts (overestimates peculiar velocity by ~ 100 km/s at z~0.04). Here we demonstrate where the approximation breaks down, the systematic offset it introduces, and how the exact calculation should be implemented.Comment: 6 pages, 4 figures, accepted by MNRAS; revision adds footnote 3, a couple of references, and some minor tweaks to tex

    On the road to Enlighten-ment: establishing an institutional repository service for the University of Glasgow

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    Purpose ā€“ The purpose of this paper is to chart the development and growth of open access and institutional repositories at the University of Glasgow, Scotland from initial work in 2001 to the University's recently launched service, Enlighten. The University of Glasgow is a signatory to the Scottish Open Access Declaration and recently released a statement on Open Access.<p></p> Design/methodology/approach ā€“ The study will focus on the key lessons learned through a twin track approach of advocacy and service development during the DAEDALUS Project (2002-2005) and the transition of that work to a University service called Enlighten. This service includes a repository for published and peer-reviewed papers which has now had over 2 million hits and over 270,000 PDF downloads since it was established in February 2004.<p></p> Findings ā€“ The paper reveals the lessons learned by the Library and the project team. It also identifies the range of issues which must be addressed in the successful implementation of a repository and its transition to a production service. These include the development of content policies, copyright clearance and the cultural change necessary to populate a repository service. These challenges have and continue to be addressed by the repository team at the University of Glasgow.<p></p> Originality/value ā€“ This paper provides details of the lessons learned in the practical experience of setting up an institutional repository and ensuring its transition to a full and supported University service. It will be of particular interest to institutions implementing a repository or running a pilot service.<p></p&gt

    Mechanisms Involved in Lysis of Luteal Tissue in the Mare

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    This thesis set out to investigate the role of Prostaglandin F-2alpha (PGF-2alpha) in luteolysis in the mare and to determine any alterations in PGF-2alpha production between normal cycling mares and mares in prolonged dioestrus

    5.1. Response: Living a Semi-digital Kinda Life

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    The following observations draw on my personal experience as an archaeologist working in the Eastern Mediterranean who has dabbled in the digital world. In considering the papers in this volume, I reflect on what it means to ā€œlive a digital lifeā€ in field archaeology. I argue we are living a ā€œsemi-digital kinda lifeā€ (Ć  la Third Eye Blind, the US rock band formed in the early 1990s) where many of us are part paper and part digital, which I contend is not a bad state of affairs. In assessing our half in/half out digital archaeology, I speculate that new technologies have the tendency to create, or reinforce, divisions between genders, developed and less-developed nations, and practice and theory. These thought-provoking chapters illustrate the very bright future for digital archaeological fieldwork and data collection, but there is still work to be done ā€“ to improve, expand, and include missing elements into digital archaeology.https://dc.uwm.edu/arthist_mobilizingthepast/1019/thumbnail.jp

    A study of hydrolases and their release from trichomonads

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    The acid hydrolase N-acetyl-Beta-D-glucosaminadase (NAGase) la a high activity lysosomal enzyme in trichomonads. Tritririchomonas foetus (strains F2, KV1 and CA84-2), Trichomonas vaginalis and Trichomonas augusta all contained and released NAGase. Analysis of NAGase using electrophoretic techniques demonstrated in all the Tritririchomonas foetus strains the same four major forms, named NAGase 1-4, whose mobility suggested apparent M,s of 54 000, 89 000, 100 000 and 158 000 respectively. Trichomonas vaginalis and Trichomonas augusta, however, each contained a single form of this enzyme of apparant M,s 138 000 and 107 000 respectively. In all cases the intracellular and extracellular forms of NAGase appeared to be identical. Growth of Tritririchomonas foetus, F2, in the presence of the glycosylation inhibitor, tunicamycin, resulted in an extra NAGase band with higher mobility assumed to be a non-glycosylated but active enzyme form. NAGase 3 mobility was simultaneously diminished. Extra NAGase forms wars also observed after incubating this parasite In serum free media containing the two proteinase inhibitors, leupeptin and Z-Phe-Phe-CHN2, indicating that proteolytic processing may be involved in the production of NAGase forms. NAGase 1, the enzyme with an apparent M, of 54 000, was purified from Tritririchomonas foetus, F2. Preparative Isoelectric focusing was used to separate the four NAGase forms and as the first step in its purification. Total denuturation of NAGase 1 before electrophoresis produced a decrease in mobility from an apparent M, of 54 000 to a doublet of apparent M,s of 68 000 and 70 000. This transformation was found to be complete within 2 min at 50Ā°C but was dependent at this temperature on the presence of both SDS and Beta-mercaptoethanol. This transformation also occured without sample buffer at 100Ā°C and may relate to the breaking of disulphide bridges. Treatment of NAGase 1 with endoglycosidase reduced its apparent M, by 2000, indicating the enzyme to be an N-linked glycoprotein. Trichomonas vaginalis and Tritririchomonas foetus were also found to contain and release acid phosphatase. SDS-PAQE analysis of this hydrolase found one form with an apparent M, of 126 000 In Tritririchomonas foetus, strains F2 and KV1, Trichomonas augusta also had one form of apparent M, 135 000 while Trichomonas vaginalis contained and released two forms with apparent M,s of 155 000 and 160 000. Despite several immunisation attempts purified NAGase 1 was found to be non-antigenic in rabbits and so It was not possible to analyse the release processes In the detail originally proposed. However, although the results have not allowed details of the release mechanisms and physiology, they have confirmed release and provided more Information on the properties of the hydrolases, especially NAGase

    Evaluation of dental therapists undertaking dental examinations in a school setting in Scotland

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    Objective: To measure agreement between dental therapists and the Scottish gold-standard dentist undertaking National Dental Inspection Programme (NDIP) examinations. Methods: A study of interexaminer agreement between 19 dental therapists and the national gold-standard dentist was carried out. Pre-calibration training used the caries diagnostic criteria and examination techniques agreed by the British Association for the Study of Community Dentistry (BASCD). Twenty-three 5-year-old children (Primary 1) and 17 11-year-old children (Primary 7) children were examined. Agreement was assessed using kappa statistics on d 3 mft and D 3 MFT for P1 and P7 children, sensitivity and speciļ¬city values, and kappa statistics on d 3 t/D 3 T and ft/FT. Calibration data on P1 and P7 children from 2009ā€“2012 involving dentists as examiners were used for comparison. Economic evaluation was undertaken using a cost minimization analysis approach. Results: The mean kappa score was 0.84 (SD 0.07) ranging from 0.69 to 0.94. All dental therapists scored good or very good agreement with the gold-standard dentist. This compares with historic NDIP calibration data with dentists, against the same gold-standard dentist, where the mean kappa value was 0.68 (SD 0.22) with a range of 0.35-1.00. The mean sensitivity score was 0.98 (SD 0.04) (range 0.88-1.0) and mean speciļ¬city score was 0.90 (SD 0.06) (range 0.78-0.96). Health economic analysis estimated that salary costs would be 33.6% lower if dental therapists were substituted for dentists in the year 2013, with an estimated saving of approximately Ā£103 646 per annum on the national budget. Conclusion: We conclude that dental therapists show a high level of interexaminer agreement, and with the appropriate annual training and calibration, they could undertake dental examinations as part of the NDIP programme

    The use and effectiveness of the eLib subject gateways: a preliminary investigation

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    Internet subject gateways were set up under the Electronic Libraries Programme (eLib) in order to address some of the problems of searching the Internet which have been identified by information professionals, i.e. locating relevant, good quality information. This preliminary study examines the extent to which academics in two universities use three eLib subject gateways (EEVL, OMNI and SOSIG). The results are generally encouraging for the eLib programme, but it is necessary for the gateways to be more effectively promoted. The study also found that academics do not have the same misgivings about the general search engines as the information professionals and seem to use them more readily than the gateways

    A Study to Determine the Impact of Team Teaching on Pupil Achievement in a Fourth Grade Classroom

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    This study is undertaken in order to determine whether fourth grade children, taught in a school horizontally organized for team teaching, will achieve as well as, or better than, fourth grade children taught in a school horizontally organized on a self-contained classroom basis

    Manipulation of the host cell response to infection with Toxoplasma gondii

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    The principal aim of the work presented in this thesis was to investigate the host-pathogen interaction in Toxoplasma gondii infected cells and to elucidate which proteins and pathways were involved in the host response to infection. Toxoplasma gondii is of clinical importance for both human and veterinary disease. There are currently no drugs available to treat the chronic stage of disease. The transcriptional response of host cells to Toxoplasma infection has previously been investigated using microarrays. Proteins are the functional molecules in the cell and the protein expression response is likely to differ from the transcriptional response due to gene expression control and post translational modifications. The advantage of a global proteomic expression profiling study of Toxoplasma gondii infected cells is that, in principle, all possible host responses could be identified without pre-supposing a specific mechanism. Advanced proteomic methods were developed and used to investigate the host protein response to infection with Toxoplasma gondii. A conventional gel-to-gel approach was used in concert with difference gel electrophoresis (DIGE) to investigate the protein expression in infected cells. This part of the work concluded that the patterns of protein expression in infected cells showed clear differences from that of the non-infected cell. This resulted in the unambiguous identification of one hundred and fifty seven host proteins which changed in expression during infection with Toxoplasma gondii. Many proteins not previously implicated in response to infection were identified. The results from the proteomic studies were compared with the transcriptional study in order to determine the gene to protein correlation in Toxoplasma gondii infected cells. A weakly positive correlation between gene and protein expression was determined. To investigate whether the host response is uniquely tailored to an individual pathogen or whether cells have a common response to infection, the protein response to a second intracellular parasite, Leishmania major, was investigated. Far fewer changes were seen in the L.major infected cell proteome, proving that the host response to infection is unique to the pathogen. Phosphorylation is one the most common post translational modifications therefore the host cell phosphoproteome was investigated alongside the steady state proteome of infected cells using three techniques and proteins specifically phosphorylated due to the presence of the parasite were identified. Functional analysis of the modulated proteins revealed extensive modulation of many pathways and functions within the infected host cell including glycolytic, mitotic and structural proteins. Over one third of all the modulated proteins identified were mitochondrial. Overall the findings detailed in this thesis indicate that the host cell has a highly specific response to Toxoplasma gondii infection and that many host cell functions are modulated due to the presence of the parasite and reveal the intimate molecular relationship between host and parasite
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