946 research outputs found

    Examination of specimens for mycobacteria in clinical laboratories in 21 countries: a 10-year review of the UK National Quality Assessment Scheme for Mycobacteria Culture

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    ABSTRACTResults from clinical diagnostic microbiology laboratories taking part in the UK National Quality Assessment Service (UK NEQAS) scheme for Mycobacteria Culture between 1993 and 2003 were evaluated and assessed to determine whether the perceived increase in the use of rapid methods is improving time-to-positive reporting of results. Four simulated sputum specimens containing mycobacteria in mixed cultures with normal commensal organisms were distributed three times a year. Participating laboratories were required to report on the presence of ‘mycobacteria’ and on the time required to obtain a positive result. The overall level of performance with the mycobacteria culture external quality assessment specimens remained consistently high, with an average success rate of 94% over 10 years. The mean time-to-positive decreased from 24 to 17 days during the previous 8 years. A survey questionnaire, circulated in 2002, addressed the use of continuous automated mycobacterial liquid culture (CAMLiC) and molecular methods. The increase in the use of rapid culture methods for the detection of Mycobacterium tuberculosis has resulted in an overall reduction in time-to-positive data reported by participants, and has provided an indication of participants’ ability to meet the 21-day target recommended by the CDC for the detection and identification of M. tuberculosis

    A five year outbreak of methicillin-susceptible Staphylococcus aureus phage type 53,85 in a regional neonatal unit

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    We identified a 5-year outbreak of a methicillin-susceptible Staphylococcus aureus (MSSA) strain, affecting 202 babies on a neonatal unit, by routine weekly phage typing all S. aureus isolates. Multiple staged control measures including strict emphasis on hand hygiene, environmental and staff surveillance sampling, and application of topical hexachlorophane powder failed to end the outbreak. S. aureus PT 53,85 (SA5385) was found on opened packs of Stomahesive®, used as a neonatal skin protectant. Only following the implementation of aseptic handling of Stomahesive®, and the use of topical mupirocin for staff nasal carriers of SA5385, and for babies colonized or infected with S. aureus, did the isolation rate of SA5385 decline. DNA fingerprinting indicated that [gt-or-equal, slanted]95% of SA5385 isolates were clonal. In vitro death rates of SA5385 on Stomahesive® with human serum were significantly lower than on Stomahesive® alone (P = 0·04), and on cotton sheet with serum (P = 0·04), highlighting the potential of this material as a survival niche. Phage typing remains a valuable, inexpensive and simple method for monitoring nosocomial MSSA infection

    Beyond the individual in the evolution of language

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    This thesis concerns the evolution of language. A proliferation of theoretical models have been presented in recent years purporting to offer evolutionary accounts for various aspects of modern languages. These models rely heavily on abstract mechanistic models of the production and reception of language by modern humans, drawn from various approaches in linguistics which aim at such models. A very basic and ubiquitous assumption is that expressions have meaning in virtue of being associated with internal representations, and that therefore the evolution of language can be modelled on the basis of individuals trying to produce external manifestations of these internal “meanings”. I examine the role of this assumption in language evolution theorising, and review evidence from neuroscience and first language acquisition relevant to the validity of this assumption. The chaotic nature of the relationship between “meaning” and the brain undermines the supposition that the evolution of language was driven by spontaneous association between internal structures and external forms. I then turn to the philosophical basis of language evolution theorising, adopting a Wittgensteinian perspective on the cognitive interpretation of linguistic theories. I argue that the theoretical apparatus of such approaches is embedded in language games whose complicated rules relate to linguistic behaviour (and idealisations of that behaviour) but not to neural organisation. The reinterpretation of such descriptions of language as descriptions of the internal structures of language users is rejected as a grammatical confusion: if the rules for constructing linguistic theory descriptions do not mention neural structures, then theoretical descriptions of the linguistic abilities of an individual say nothing non-trivial about their internal brain structure. I do not deny that it would, in principle, be possible to reduce linguistic theories (reinterpreted as mechanistic descriptions) to neural structures, but claim that this possibility is guaranteed only by leaving the practice of re-describing physical brain descriptions entirely unconstrained. Thus the idea that we can reasonably infer the behaviour of humans and prehumans in more primitive communicative environments by manipulation of the models of linguistic theories is unfounded: we have no idea how such a manipulation would translate into statements about neural organisation, and so no idea how plausible such statements about earlier neural organisation (and the resultant behaviours) are. As such, cognitive interpretations of linguistic theories provide no better ground for statements about behaviour during earlier stages in the evolution of language than guessing. Rejecting internal-mechanism based accounts as unfounded leaves the evolution of language unexplained. In the latter parts of this thesis, I offer a more neutral approach which is sensitive to the limited possibilities available for making predictions about human (and pre-human) behaviour at earlier stages in the evolution of language. Rather than focusing on the individual and imputed internal language machinery, the account considers the communicative affordances available to individuals. The shifts in what individuals can learn to do in interaction with others, that result in turn from the learning of interactive practices by others, form the basis of this account. General trends in the development of communicative affordances are used to account for generalisations over attested semantic change, and to suggest how certain aspects of modern language use developed without simply assuming that it is “natural” for humans to (spontaneously) behave in these ways. The model is used in an account of the evolution and common structure of colour terms across different languages

    Development of magnetostrictive active members for control of space structures

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    The goal of this Phase 2 Small Business Innovative Research (SBIR) project was to determine the technical feasibility of developing magnetostrictive active members for use as truss elements in space structures. Active members control elastic vibrations of truss-based space structures and integrate the functions of truss structure element, actively controlled actuator, and sensor. The active members must control structural motion to the sub-micron level and, for many proposed space applications, work at cryogenic temperatures. Under this program both room temperature and cryogenic temperature magnetostrictive active members were designed, fabricated, and tested. The results of these performance tests indicated that room temperature magnetostrictive actuators feature higher strain, stiffness, and force capability with lower amplifier requirements than similarly sized piezoelectric or electrostrictive active members, at the cost of higher mass. Two different cryogenic temperature magnetostrictive materials were tested at liquid nitrogen temperatures, both with larger strain capability than the room temperature magnetostrictive materials. The cryogenic active member development included the design and fabrication of a cryostat that allows operation of the cryogenic active member in a space structure testbed

    An Eye-Opening Approach to Developing and Communicating Integrated Environmental Assessments

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    Communication among managers, the public, and scientists is the key to successful ecosystem management; however, the varied perspectives and interests of these groups can make such communication difficult. One way to achieve effective communication is to develop a common knowledge base by combining syntheses of key scientific results with information-rich visual elements. Within a management landscape, integrated environmental assessments provide a useful framework for evaluating resources and directing management efforts. The integrated assessment process involves (1) initial investigation, (2) development of a conceptual framework, (3) data navigation, (4) environmental report cards, and (5) science communication. Each step requires the synthesis and visualization of information on the status and trends connected with multiple natural resources. We provide a case study, using examples from selected National Park Service sites in the mid-Atlantic region of the United States. Visual elements (conceptual diagrams, maps, graphs, tables, and photographs) were used to facilitate comparative assessments and to provide a more visual, or eye-opening , approach to effective environmental decision making

    Unequal relationships in high and low power distance societies: a comparative study of tutor - student role relations in Britain and China

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    This study investigated people's conceptions of an unequal role relationship in two different types of society: a high power distance society and a low power distance society. The study focuses on the role relationship of tutor and student. British and Chinese tutors and postgraduate students completed a questionnaire that probed their conceptions of degrees of power differential and social distance/closeness in this role relationship. ANOVA results yielded a significant nationality effect for both aspects. Chinese respondents judged the relationship to be closer and to have a greater power differential than did British respondents. Written comments on the questionnaire and interviews with 9 Chinese academics who had experienced both British and Chinese academic environments supported the statistical findings and indicated that there are fundamental ideological differences associated with the differing conceptions. The results are discussed in relation to Western and Asian concepts of leadership and differing perspectives on the compatibility/incompatibility of power and distance/closeness

    Effects of gastroprotectant drugs for the prevention and treatment of peptic ulcer disease and its complications: a meta-analysis of randomised trials

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    Background: Gastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs. Background: Gastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs. Methods: We searched MEDLINE and Embase from Jan 1, 1950, to Dec 31, 2015, to identify unconfounded, randomised trials of a gastroprotectant drug (defined as a PPI, prostaglandin analogue, or H2RA) versus control, or versus another gastroprotectant. Two independent researchers reviewed the search results and extracted the prespecified outcomes and key characteristics for each trial. We did meta-analyses of the effects of gastroprotectant drugs on ulcer development, bleeding, and mortality overall, according to the class of gastroprotectant, and according to the individual drug within a gastroprotectant class. Findings: We identified comparisons of gastroprotectant versus control in 849 trials (142 485 participants): 580 prevention trials (110 626 participants), 233 healing trials (24 033 participants), and 36 trials for the treatment of acute upper gastrointestinal bleeding (7826 participants). Comparisons of one gastroprotectant drug versus another were available in 345 trials (64 905 participants), comprising 160 prevention trials (32 959 participants), 167 healing trials (28 306 participants), and 18 trials for treatment of acute upper gastrointestinal bleeding (3640 participants). The median number of patients in each trial was 78 (IQR 44·0–210·5) and the median duration was 1·4 months (0·9–2·8). In prevention trials, gastroprotectant drugs reduced development of endoscopic ulcers (odds ratio [OR] 0·27, 95% CI 0·25–0·29; p<0·0001), symptomatic ulcers (0·25, 0·22–0·29; p<0·0001), and upper gastrointestinal bleeding (0·40, 0·32–0·50; p<0·0001), but did not significantly reduce mortality (0·85, 0·69–1·04; p=0·11). Larger proportional reductions in upper gastrointestinal bleeding were observed for PPIs than for other gastroprotectant drugs (PPIs 0·21, 99% CI 0·12–0·36; prostaglandin analogues 0·63, 0·35–1·12; H2RAs 0·49, 0·30–0·80; phet=0·0005). Gastroprotectant drugs were effective in preventing bleeding irrespective of the use of non-steroidal anti-inflammatory drugs (phet=0·56). In healing trials, gastroprotectants increased endoscopic ulcer healing (3·49, 95% CI 3·28–3·72; p<0·0001), with PPIs more effective (5·22, 99% CI 4·00–6·80) than prostaglandin analogues (2·27, 1·91–2·70) and H2RAs (3·80, 3·44–4·20; phet<0·0001). In trials among patients with acute bleeding, gastroprotectants reduced further bleeding (OR 0·68, 95% CI 0·60–0·78; p<0·0001), blood transfusion (0·75, 0·65–0·88; p=0·0003), further endoscopic intervention (0·56, 0·45–0·70; p<0·0001), and surgery (0·72, 0·61–0·84; p<0·0001), but did not significantly reduce mortality (OR 0·90, 0·72–1·11; p=0·31). PPIs had larger protective effects than did H2RAs for further bleeding (phet=0·0107) and blood transfusion (phet=0·0130). Interpretation: Gastroprotectants, in particular PPIs, reduce the risk of peptic ulcer disease and its complications and promote healing of peptic ulcers in a wide range of clinical circumstances. However, this meta-analysis might have overestimated the benefits owing to small study bias

    Screening of antimicrobial activity of diarylamines in the 2,3,5-trimethylbenzo[b]thiophene series : a structure-activity evaluation study

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    Gram positive (Bacillus cereus, Bacillus subtilis), Gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and Candida albicans as a representative of fungi were used for screening the in vitro antimicrobial activity of diarylamines in the 2,3,5-trimethyl benzo[b]thiophene series bearing different substituents, synthesised by us using the palladium-catalyzed C-N coupling methodology. The minimal inhibitory concentration (MIC) and structure-activity relationships (SARs) were evaluated.Fundação Calouste Gulbenkian. Fundação para a Ciência e Tecnologia

    The UK market for energy service contracts in 2014–2015

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    This paper provides an overview of the UK market for energy service contracts in 2014 and highlights the growing role of intermediaries. Using information from secondary literature and interviews, it identifies the businesses offering energy service contracts, the sectors and organisations that are purchasing those contracts, the types of contract that are available, the areas of market growth and the reasons for that growth. The paper finds that the UK market is relatively large, highly diverse, concentrated in particular sectors and types of site and overwhelmingly focused upon established technologies with high rates of return. A major driver is the emergence of procurement frameworks for energy service contracts in the public sector. These act as intermediaries between clients and contractors, thereby lowering transaction costs and facilitating learning. The market is struggling to become established in commercial offices, largely as a result of split incentives, and is unlikely to develop further in this sector without different business models, tenancy arrangements and policy initiatives. Overall, the paper concludes that energy service contracts can play an important role in the transition to a low-carbon economy, especially when supported by intermediaries, but their potential is still limited by high transaction costs
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