558 research outputs found
Genetic Studies of Sulfadiazine-resistant and Methionine-requiring \u3cem\u3eNeisseria\u3c/em\u3e Isolated From Clinical Material
Deoxyribonucleate (DNA) preparations were extracted from Neisseria meningitidis (four isolates from spinal fluid and blood) and N. gonorrhoeae strains, all of which were resistant to sulfadiazine upon primary isolation. These DNA preparations, together with others from in vitro mutants of N. meningitidis and N. perflava, were examined in transformation tests by using as recipient a drug-susceptible strain of N. meningitidis (Ne 15 Sul-s Met+) which was able to grow in a methionine-free defined medium. The sulfadiazine resistance typical of each donor was introduced into the uniform constitution of this recipient. Production of p-aminobenzoic acid was not significantly altered thereby. Transformants elicited by DNA from the N. meningitidis clinical isolates were resistant to at least 200 ÎŒg of sulfadiazine/ml, and did not show a requirement for methionine (Sul-r Met+). DNA from six strains of N. gonorrhoeae, which were isolated during the period of therapeutic use of sulfonamides, conveyed lower degrees of resistance and, invariably, a concurrent methionine requirement (Sul-r/Metâ). The requirement of these transformants, and that of in vitro mutants selected on sulfadiazine-agar, was satisfied by methionine, but not by vitamin B12, homocysteine, cystathionine, homoserine, or cysteine. Sul-r Met+ and Sul-r/Metâ loci could coexist in the same genome, but were segregated during transformation. On the other hand, the dual Sul-r/Metâ properties were not separated by recombination, but were eliminated together. DNA from various Sul-r/Metâ clones tested against recipients having nonidentical Sul-r/Metâ mutant sites yielded Sul-s Met+ transformants. The met locus involved is genetically complex, and will be a valuable tool for studies of genetic fine structure of members of Neisseria, and of genetic homology between species
OA16.01. Patients, physicians, and CAM providers regard communication as central for integrating conventional and CAM therapies for chronic pain
Metapopulation viability of an endangered shorebird depends on dispersal and human-created habitats: piping plovers (Charadrius melodus) and prairie rivers
Compressed gas domestic aerosol valve design using high viscous product
Most of the current universal consumer aerosol products using high
viscous product such as cooking oil, antiperspirants, hair removal cream
are primarily used LPG (Liquefied Petroleum Gas) propellant which is
unfriendly environmental. The advantages of the new innovative
technology described in this paper are:
i. No butane or other liquefied hydrocarbon gas is used as a propellant
and it replaced with Compressed air, nitrogen or other safe gas
propellant.
ii. Customer acceptable spray quality and consistency during can lifetime
iii. Conventional cans and filling technology
There is only a feasible energy source which is inert gas (i.e.
compressed air) to replace VOCs (Volatile Organic Compounds) and
greenhouse gases, which must be avoided, to improve atomisation by
generating gas bubbles and turbulence inside the atomiser insert and the
actuator. This research concentrates on using âbubbly flowâ in the valve
stem, with injection of compressed gas into the passing flow, thus also
generating turbulence.
The new valve designed in this investigation using inert gases has
advantageous over conventional valve with butane propellant using high
viscous product (> 400 Cp) because, when the valving arrangement is
fully open, there are negligible energy losses as fluid passes through the
valve from the interior of the container to the actuator insert. The use of
valving arrangement thus permits all pressure drops to be controlled,
resulting in improved control of atomising efficiency and flow rate,
whereas in conventional valves a significant pressure drops occurs
through the valve which has a complex effect on the corresponding
spray
Bergman kernel and complex singularity exponent
We give a precise estimate of the Bergman kernel for the model domain defined
by where
is a holomorphic map from to ,
in terms of the complex singularity exponent of .Comment: to appear in Science in China, a special issue dedicated to Professor
Zhong Tongde's 80th birthda
Designing citizen science tools for learning: lessons learnt from the iterative development of nQuire
This paper reports on a 4-year research and development case study about the design of citizen science tools for inquiry learning. It details the process of iterative pedagogy-led design and evaluation of the nQuire toolkit, a set of web-based and mobile tools scaffolding the creation of online citizen science investigations. The design involved an expert review of inquiry learning and citizen science, combined with user experience studies involving more than 200 users. These have informed a concept that we have termed âcitizen inquiryâ, which engages members of the public alongside scientists in setting up, running, managing or contributing to citizen science projects with a main aim of learning about the scientific method through doing science by interaction with others. A design-based research (DBR) methodology was adopted for the iterative design and evaluation of citizen science tools. DBR was focused on the refinement of a central concept, âcitizen inquiryâ, by exploring how it can be instantiated in educational technologies and interventions. The empirical evaluation and iteration of technologies involved three design experiments with end users, user interviews, and insights from pedagogy and user experience experts. Evidence from the iterative development of nQuire led to the production of a set of interaction design principles that aim to guide the development of online, learning-centred, citizen science projects. Eight design guidelines are proposed: users as producers of knowledge, topics before tools, mobile affordances, scaffolds to the process of scientific inquiry, learning by doing as key message, being part of a community as key message, every visit brings a reward, and value users and their time
Mapping species distributions: A comparison of skilled naturalist and lay citizen science recording
To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UKâs national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. For the widespread common carder (Bombus pascuorum), traditional recording scheme data were patchy, both spatially and temporally, reflecting active record centre rather than species distribution. Lay citizen science records displayed more extensive geographic coverage, reflecting human population density, thus offering better opportunities to account for recording effort. For the rapidly spreading tree bumblebee (Bombus hypnorum), both recording approaches revealed similar distributions due to a dedicated mapping project which overcame the patchy nature of naturalist records. We recommend, where possible, complementing skilled naturalist recording with lay citizen science programmes to obtain a nation-wide capability, and stress the need for timely uploading of data to the national repository
Monitoring ecological change in UK woodlands and rivers: an exploration of the relational geographies of citizen science
The adoption of citizen science methodologies by environmental organisations and ecologists entrusts the task of collecting ecological data to nonâexperts operating at a local scale. This presents individuals and communities with opportunities to monitor ecological change and contribute to local environmental management. Little is known about why volunteers choose to participate in burgeoning contemporary citizen science research initiatives. The aim of this paper is thus to explore volunteer motivation for involvement in two environmental citizen science initiatives, based in the United Kingdom. It contributes to understandings of the socioâgeographical influences that act on participation in environmental citizen science. It is proposed within this paper that affective connections with local geographies provide a conceptual framework for understanding citizen science motivations. The paper discusses the main themes emerging from siteâbased, inâdepth interviews with 22 citizen science participants in various UK locations. The study revealed that early affective bonds formed with ecological spaces endured throughout life courses, while citizen science participation offered a way of remaining connected to local environments. The paper reflects on the endurance of affective environmental bonds and their manifestation within the expressed motivations for citizen science participation, which emerged as fulfilling a compulsion to observe ecological surroundings, a desire to participate in environmental research and a commitment to protecting local environments. The paper proposes that citizen science participation offers a framework to connect to and protect local and global affinity spaces, while assisting in monitoring global environmental change
Biodiversity in urban gardens: assessing the accuracy of citizen science data on garden hedgehogs
Urban gardens provide a rich habitat for species that are declining in rural areas. However, collecting data in gardens can be logistically-challenging, time-consuming and intrusive to residents. This study examines the potential of citizen scientists to record hedgehog sightings and collect habitat data within their own gardens using an online questionnaire. Focussing on a charismatic species meant that the number of responses was high (516 responses were obtained in 6 weeks, with a ~ 50:50% split between gardens
with and without hedgehog sightings). While many factors commonly thought to influence hedgehog
presence (e.g. compost heaps) were present in many hedgehog-frequented gardens, they were not discriminatory as they were also found in gardens where hedgehogs were not seen. Respondents were most likely to have seen hedgehogs in their garden if they had also seen hedgehogs elsewhere in their neighbourhood. However, primary fieldwork using hedgehog âfootprint tunnelsâ showed that hedgehogs were found to be just as prevalent in gardens in which hedgehogs had previously been reported as gardens where they had not been reported. Combining these results indicates that hedgehogs may be more common in urban and semi-urban gardens than previously believed, and that casual volunteer records of hedgehogs may be influenced more by the observer than by habitat preferences of the animal. When verified, volunteer records can provide useful information, but care is needed in interpreting these data
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