1,020 research outputs found
The nasa electronics research center and its relationship with industry
NASA electronics center and relationship with industry, universities, and institutes for increased level of space electronic
Project MOSI: rationale and pilot-study results of an initiative to help protect zoo animals from mosquito-transmitted pathogens and contribute data on mosquito spatio–temporal distribution change
Mosquito-borne pathogens pose major threats to both wildlife and human health and, largely as a result of unintentional human-aided dispersal of their vector species, their cumulative threat is on the rise. Anthropogenic climate change is expected to be an increasingly significant driver of mosquito dispersal and associated disease spread. The potential health implications of changes in the spatio-temporal distribution of mosquitoes highlight the importance of ongoing surveillance and, where necessary, vector control and other health-management measures. The World Association of Zoos and Aquariums initiative, Project MOSI, was established to help protect vulnerable wildlife species in zoological facilities from mosquito-transmitted pathogens by establishing a zoo-based network of fixed mosquito monitoring sites to assist wildlife health management and contribute data on mosquito spatio-temporal distribution changes. A pilot study for Project MOSI is described here, including project rationale and results that confirm the feasibility of conducting basic standardized year-round mosquito trapping and monitoring in a zoo environment
The development of a toxicity database using freshwater macroinvertebrates, and its application to the protection of South African water resources
There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies
Equation of state for the 2+1 dimensional Gross-Neveu model at order 1/N
We calculate the equation of state of the Gross-Neveu model in 2+1 dimensions
at order 1/N, where N is the number of fermion species. We make use of a
general formula valid for four-fermion theories, previously applied to the
model in 1+1 dimensions. We consider both the discrete and continuous symmetry
versions of the model. We show that the pion-like excitations give the dominant
contribution at low temperatures. The range of validity for such pion dominance
is analyzed. The complete analysis from low to high temperatures also shows
that in the critical region the role of composite states is relevant, even for
quite large N, and that the free-component behaviour at high T starts at about
twice the mean field critical temperature.Comment: 19 pages, RevTeX, 10 figures.p
The homotopy theory of simplicial props
The category of (colored) props is an enhancement of the category of colored
operads, and thus of the category of small categories. In this paper, the
second in a series on "higher props," we show that the category of all small
colored simplicial props admits a cofibrantly generated model category
structure. With this model structure, the forgetful functor from props to
operads is a right Quillen functor.Comment: Final version, to appear in Israel J. Mat
Surveillance of catheter-related infections : the supplementary role of the microbiology laboratory
BACKGROUND : The burden of catheter-related infections (CRIs) in developing countries is severe. In South Africa, a
standardised surveillance definition does not exist and the collection of catheter days is challenging. The aim of the
study was to provide baseline data on the prevalence of CRIs and to describe the epidemiology of CRI events
within a tertiary academic hospital.
METHODS : Surveillance was laboratory-based and conducted for a six month period. A microbiologically confirmed
CRBSI (MC-CRBSI) event was defined as the isolation of the same microorganism from the catheter and concomitant
blood cultures (BCs), within 48 h of catheter removal, which were not related to an infection at another site.
RESULTS : A total of 508 catheters, removed from 332 patients, were processed by the laboratory, of which only 50%
(253/508 removed from 143/332 patients) of the catheters were accompanied by BCs within 48 h. Sixty-five episodes of
MC-CRBSI in 57 patients were detected, involving 71 catheters and 195 microbial isolates. The institutional prevalence
rate was 3.7 episodes per 1 000 admissions and 5.8 episodes per 10 000 in-patient days. Catheter day data was collected
in only six wards of the hospital. The pooled laboratory incidence was 10.1 MC-CRBSI episodes per 1 000 catheter days,
whereas the hospital-based central line-associated bloodstream infection (CLABSI) rate was pooled at 5.7 episodes
per 1 000 catheter days. The majority of patients had an underlying gastro-intestinal condition (33%; 19/56) with a
non-tunnelled, triple-lumen central venous catheter, placed in the subclavian vein (38%; 27/71). The most
predominant pathogen was methicillin-resistant Staphylococcus epidermidis (28%; 55/195), followed by
extensively-drug resistant Acinetobacter baumannii (18%; 35/195).
CONCLUSIONS : Catheter-related infection prevention and control efforts require urgent attention, not only to keep
patients safe from preventable harm, but to prevent the spread of multidrug resistant microorganisms.RESCOM,Faculty of Health Science, UP, National Health Laboratory Service (NHLS) and
the National Research Foundation (NRF).http://www.biomedcentral.com/bmcinfectdis/hb201
`Iconoclastic', Categorical Quantum Gravity
This is a two-part, `2-in-1' paper. In Part I, the introductory talk at
`Glafka--2004: Iconoclastic Approaches to Quantum Gravity' international
theoretical physics conference is presented in paper form (without references).
In Part II, the more technical talk, originally titled ``Abstract Differential
Geometric Excursion to Classical and Quantum Gravity'', is presented in paper
form (with citations). The two parts are closely entwined, as Part I makes
general motivating remarks for Part II.Comment: 34 pages, in paper form 2 talks given at ``Glafka--2004: Iconoclastic
Approaches to Quantum Gravity'' international theoretical physics conference,
Athens, Greece (summer 2004
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