1,231 research outputs found

    A computer‐aided continuous assessment system

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    A high‐quality assessment system should have the following attributes: rapid feedback to the students, appropriate and detailed feedback, and an effective grading system which provides an accurate overall grade as well as information which identifies the student's weak areas. As stafflstudent ratios worsen, providing such a system will become more difficult and consequently computer assistance in this task is becoming more attractive. This paper describes a Computer‐Aided Assessment (CAA) system based on a modified version of the multiple‐choice questionnaire. The CAA has been designed to be used in continuous assessment, with features that discourage plagiarism and provide appropriate feedback Over a hundred students were tested using this CAA and the results were compared with a more traditional assessment system. In addition, questionnaires were used to assess the student's reaction to the CAA. The results were highly satisfactory, and a more advanced version of the original software is under consideration

    GABA-B receptor function in healthy volunteers, a pharmacokinetic and pharmacodynamic study of two doses of baclofen compared to placebo

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    AIMS AND HYPOTHESIS To assess the subjective and objective effects of baclofen on brain function in healthy volunteers. BACKGROUND Recent evidence suggests baclofen, a γ-aminobutyric acid type B (GABA-B) receptor agonist, reduces alcohol consumption and craving and promotes abstinence in alcoholics. However, characterisation of the GABA-B receptor system in clinical addiction is limited, and it is unclear why some patients require, or tolerate, higher doses to treat alcoholism. This study assesses the effects of baclofen on brain function in healthy volunteers to inform future studies investigating the sensitivity of GABA-B receptors in alcohol addiction. METHODS Eight healthy male volunteers completed a double blind randomised 3-way cross over study, receiving oral placebo (vitamin C 100mg), 10mg and 60mg baclofen. Subjective and objective measurements were taken at baseline (before medication) and at +30mins, 1, 2, 3, 4 and 6 hours after dosing. Objective measures included blood plasma samples, heart rate and blood pressure. Subjective measures included; the Subjective High Assessment Questionnaire (SHAS), visual analogue scales for sleepy, relaxed, tense and alert and a motor coordination task (zig-zag task). Pharmacokinetic data was obtained using liquid chromatography mass-spectrometry (LC-MS) to measure plasma baclofen concentrations. RESULTS 60mg Baclofen showed changes in subjective measures peaking at 2 hours post dosing compared with placebo, including a significant increase (p<0.05) in total SHAS scores with individual items, including feeling ‘drunk or intoxicated’, effects of alcohol and ‘muddled or confused’ particular affected.. Systolic blood pressure was significantly increased (p<0.05) at the 2 hours post 60mg dose. For both 10mg and 60mg baclofen, peak plasma concentration was achieved 60 minutes post dose. Pharmacokinetic data will be presented. There were no significant changes in these measures between 10mg Baclofen and placebo. CONCLUSIONS The objective and subjective measures used in this study are able to differentiate between placebo and 60mg baclofen. These findings will inform further research investigating the sensitivity of GABA-B receptors in alcohol addiction

    Use of sequence-based typing and multiplex PCR to identify clonal lineages of outbreak strains of Acinetobacter baumannii

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    ABSTRACTRepresentatives (n = 31) of outbreak strains of Acinetobacter baumannii from five countries fell into three clear groups, designated Groups 1–3, based on their ompA (outer-membrane protein A), csuE (part of a pilus assembly system required for biofilm formation) and blaOXA-51-like (the intrinsic carbapenemase gene in A. baumannii) gene sequences. With the exception of the closely related alleles within the Group 1 clonal complex, alleles at each locus were highly distinct from each other, with a minimum of 14 nucleotide differences between any two alleles. Isolates within a group shared the same combination of alleles at the three loci, providing compelling evidence that the outbreak strains investigated belonged to three clonal lineages. These corresponded to the previously identified European clones I–III. Sequence differences among the alleles were used to design multiplex PCRs to rapidly assign isolates belonging to particular genotypes to sequence groups. In the UK, genotypes belonging to the Group 1 clonal complex have been particularly successful, accounting for the vast majority of isolates referred from hospitals experiencing problems with Acinetobacter

    The effect of sevoflurane induction on the myocardial performance index in healthy individuals

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    Background: The myocardial performance (Tei) index is a simple, reproducible and easily performed measure of cardiac performance. Its ease of use and proven clinical application make this an attractive measure perioperatively. For appropriate use of this index under sevoflurane anaesthesia, drug effects on normal values need to be defined.Methods: A total of 38 ASA 1 patients were consecutively included in this study. Induction was by sevoflurane inhalation. Steady state was defined as 3–5 min spontaneous tidal ventilation with an end-tidal sevoflurane concentration of at least 2.3%. Baseline and steady-state measurements included haemodynamics and four-chamber transthoracic echocardiographic image acquisition. Offline analysis focused on tissue Doppler studies of the lateral mitral annulus. Discrete variables before and after induction were compared.Results: Changes in simple haemodynamic variables were as expected (Systolic blood pressure: mean [95% CI] –11.62 [–15.96 to –7.27]; diastolic blood pressure: mean [95% CI] –6.46 [–11.65 to –1.28]; heart rate: mean [95% CI] 2.66 [–1.72 to 7.05]). Isovolumic contraction time decreased from baseline (mean [95% CI] –3.37 [–5.11 to –1.64]). Isovolumic relaxation time also decreased (mean [95% CI] –7.44 [–10.23 to –4.66]). Ejection time decreased (mean [95% CI] –4.41 [–11.62 to 2.80]). This saw a consistent decrease in the Tei index with a p-value of &lt; 0.0001 (mean [95% CI] –0.035 [–0.050 to –0.021]).Conclusion: Sevoflurane at 1-MAC minimally decreases the Tei index. This implies that, overall, myocardial mechanics/ performance in healthy individuals is not negatively affected by sevoflurane anaesthesia. Reference values for this index appear to be applicable for patients under sevoflurane anaesthesia.Keywords: Anaesthetics volatile, sevoflurane, heart, myocardial function, Tei index, tissue Doppler echocardiograph

    Phonon-like hydrogen-bond modes in protic ionic liquids

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    Gigahertz- to terahertz-frequency infrared and Raman spectra contain a wealth of information concerning the structure, intermolecular forces, and dynamics of ionic liquids. However, these spectra generally have a large number of contributions ranging from slow diffusional modes to underdamped librations and intramolecular vibrational modes. This makes it difficult to isolate effects such as the role of Coulombic and hydrogen-bonding interactions. We have applied far-infrared and ultrafast optical Kerr effect spectroscopies on carefully selected ions with a greater or lesser degree of symmetry in order to isolate spectral signals of interest. This has allowed us to demonstrate the presence of longitudinal and transverse optical phonon modes and a great similarity of alkylammonium-based protic ionic liquids to liquid water. The data show that such phonon modes will be present in all ionic liquids, requiring a reinterpretation of their spectra

    Terahertz underdamped vibrational motion governs protein-ligand binding in solution

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    Low-frequency collective vibrational modes in proteins have been proposed as being responsible for efficiently directing biochemical reactions and biological energy transport. However, evidence of the existence of delocalized vibrational modes is scarce and proof of their involvement in biological function absent. Here we apply extremely sensitive femtosecond optical Kerr-effect spectroscopy to study the depolarized Raman spectra of lysozyme and its complex with the inhibitor triacetylchitotriose in solution. Underdamped delocalized vibrational modes in the terahertz frequency domain are identified and shown to blue-shift and strengthen upon inhibitor binding. This demonstrates that the ligand-binding coordinate in proteins is underdamped and not simply solvent-controlled as previously assumed. The presence of such underdamped delocalized modes in proteins may have significant implications for the understanding of the efficiency of ligand binding and protein–molecule interactions, and has wider implications for biochemical reactivity and biological function

    Cervical intra-epithelial neoplasia in HIV-positive women after excision of the transformation zone – does the grade change?

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    Objective. After previously reporting the presence of disease by cytology findings after treatment for cervical intra-epithelial neoplasia (CIN) in 64.6% of HIV-infected women and in 13.0% of HIV-negative women, we aimed to determine the severity of cytological disease after treatment in HIV-infected women.Methods. We studied HIV-infected (N=571) women treated at the Colposcopy Clinic at Chris Hani Baragwanath Hospital, Gauteng, between April 2003 and December 2006. We compared the initial histology results with Pap smears .6 months later, and evaluated factors associated with reduction in the grade of disease.Results. Mean age was 36.68 (SD+7.33) years; mean parity was 2 (SD+1.46); mean CD4+ count was 242.70 cells/&#402;&#202;l (SD+187.56); 262 (45.80%) were receiving antiretroviral treatment. Persistent disease was detected on the repeat Pap smear in 199 (65.03%); of these, 223 (72.88%) were of a lesser grade than in the original histology results. Of the 152 with histologically confirmed CIN3, 67 (44.08%) had improved to a lesser grade, and 54 (44.63%) had normal cytology results. Among the latter two subject groups (n=141) who had CIN2 histologically, 91 (64.53%) had improved, 29 (20.57%) remained unchanged, and 20 (14.88%) had CIN3; 13 (4.25%) patients with CIN1 returned for follow-up; 11 (84.62%) of these had normal Pap smears and 2 (15.38%) had CIN3.Conclusion. Recurrences were of a lesser degree than initial histology results. This reduction in the grade of disease was related to CD4+ count, complete excision and parity. Antiretroviral therapy use did not improve outcome, perhaps owing to low initial CD4 counts

    Disaster, Relief and Political Change in Southern Ethiopia: Developments from within Suri Society

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    This chapter describes responses to the ecological crisis and political changes in Ethiopia in the early 1990s among the Suri, an agropastoral group in K„fa Region, southern Ethiopia. Data are derived from fieldwork carried out in the area after the change of regime in 1991. Attention is paid to environmental conditions and the Suri subsistence system, relations between the Suri and neighbouring ethnic groups, drought and famine in the area, in particular in the 1980s, and the Suri attitude towards the interventions of outside agencies, interethnic conflict in the period 1984-1993, Suri recovery and adaptation in the early 1990s, and the effects of drought, famine, and political upheaval on Suri socioeconomic organization, local political relations, and ethnic identities and interethnic relations. Bibliogr., notes, refASC – Publicaties niet-programma gebonde

    Validated method for the quantification of baclofen in human plasma using solid-phase extraction and liquid chromatography–tandem mass spectrometry

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    A highly sensitive and fully validated method was developed for the quantification of baclofen in human plasma. After adjusting the pH of the plasma samples using a phosphate buffer solution (pH 4), baclofen was purified using mixed mode (C8/cation exchange) solid-phase extraction (SPE) cartridges. Endogenous water-soluble compounds and lipids were removed from the cartridges before the samples were eluted and concentrated. The samples were analyzed using triple-quadrupole liquid chromatography–tandem mass spectrometry (LC–MS-MS) with triggered dynamic multiple reaction monitoring mode for simultaneous quantification and confirmation. The assay was linear from 25 to 1,000 ng/mL (r2 > 0.999; n = 6). Intraday (n = 6) and interday (n = 15) imprecisions (% relative standard deviation) were <5%, and the average recovery was 30%. The limit of detection of the method was 5 ng/mL, and the limit of quantification was 25 ng/mL. Plasma samples from healthy male volunteers (n = 9, median age: 22) given two single oral doses of baclofen (10 and 60 mg) on nonconsecutive days were analyzed to demonstrate method applicability
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