488 research outputs found
Microfungi in Drinking Water: The Role of the Frog Litoria caerulea
Microfungi were recovered from all parts of a municipal water distribution system in sub-tropical Australia even though virtually no colony-forming units were recovered from the treated water as it left the treatment plant. A study was then undertaken to determine the potential sources of the microfungal population in the distribution system. Observation of frogs (Litoria caerulea) using the internal infrastructure of a reservoir as diurnal sleeping places, together with observation of visible microfungal growth on their faecal pellets, led to an investigation of the possible involvement of this animal. Old faecal pellets were collected and sporulating fungal colonies growing on their surfaces were identified. Fresh faecal pellets were collected and analysed for microfungal content, and skin swabs were analysed for yeasts. It was found that the faeces and skin of L. caerulea carried large numbers of yeasts as well as spores of various filamentous fungal genera. While there are many possible sources of microfungal contamination of municipal drinking water supplies, this study has revealed that the Australian green tree frog L. caerulea is one of the important sources of filamentous microfungi and yeasts in water storage reservoirs in sub-tropical Australia where the animal is endemic
Making sense of business analytics : the case of two start-ups
Business analytics have enabled businesses to leverage unstructured and dispersed data in order to improve their operations and position themselves better within a highly turbulent environment. While much discussion has been focused on how businesses can move from data to insights to decision making, much less is known around how businesses actually interpret the insights provided by business analytics tools. This extended abstract proposes the use of sense-making as the theoretical lens for interpreting these insights, combined with contextual information. We will be using two case studies to further explore the applicability of our proposition
Generative mechanisms for innovation in information infrastructures
This paper investigates how innovation of ICT based services takes place within existing infrastructures, including the whole network of technology, vendors and customers. Our research question is, how can an information infrastructure provide generative mechanisms for innovation of ICT based services? Building on a critical realist approach, our empirical evidence was a case study within an international airline, aiming to diversify its services. From our analysis we propose that there are two self-reinforcement mechanisms in information infrastructures. First, we identified the innovation reinforcement mechanism, resulting in new services. Second, there is the service reinforcement mechanism, resulting in more users and profits. The practical implication of our framework is to show that although ICT-based innovation cannot be planned and managed in detail, the innovation mechanism may help organisations to facilitate the innovation process in a structured way
Three Potential Sources of Microfungi in a Treated Municipal Water Supply System in Sub-Tropical Australia
Some microfungi are known to be opportunistic human pathogens, and there is a body of scientific opinion that one of their routes of infection may be water aerosols. Others have been implicated as causative agents of odours and off-tastes in drinking water. This study was undertaken to investigate three potential sources of microfungi in a treated, oligotrophic municipal water supply system in sub-tropical Australia. Formation of the microfungal component of developing biofilm on hard surfaces in water storage reservoirs was also assessed. Inside and outside air samples were collected from two reservoirs using two types of Burkard air samplers. Biofilm and soft sediment samples were collected from the inner surfaces of asbestos cement water pipes and from pipe dead ends respectively. These were analysed for microfungal growth and sporulation using Calcofluor White stain and epifluorescent microscopy. Artificial coupons of glass, PVC and concrete were immersed in two reservoirs to assess microfungal biofilm formation. This was analysed periodically using Calcofluor White stain and epifluorescent microscopy, cultures of coupon swabs and scanning electron microscopy. Fungal spores were recovered from all air samples. The number of colonies and the genera were similar for both inside and outside air. Microfungal filaments and sporulating structures were recovered from most of the pipe inner surface biofilm and dead end sediment samples, but were sparser in the biofilm than in the sediment samples. No recognisable, vegetative filamentous fungi were found in the slowly developing biofilm on coupons. This study indicates that airborne spores are an important potential source of microfungi found in water storage reservoirs. It has also demonstrated conclusively that filamentous microfungi grow and sporulate on water pipe inner surfaces and in soft sediments within the water distribution system
Molecular mechanism of decision-making in glycosaminoglycan biosynthesis
Two major glycosaminoglycan types, heparan sulfate (HS) and chondroitin sulfate (CS), control many aspects of development and physiology in a type-specific manner. HS and CS are attached to core proteins via a common linker tetrasaccharide, but differ in their polymer backbones. How core proteins are specifically modified with HS or CS has been an enduring mystery. By reconstituting glycosaminoglycan biosynthesis in vitro, we establish that the CS-initiating N-acetylgalactosaminyltransferase CSGALNACT2 modifies all glycopeptide substrates equally, whereas the HS-initiating N-acetylglucosaminyltransferase EXTL3 is selective. Structure-function analysis reveals that acidic residues in the glycopeptide substrate and a basic exosite in EXTL3 are critical for specifying HS biosynthesis. Linker phosphorylation by the xylose kinase FAM20B accelerates linker synthesis and initiation of both HS and CS, but has no effect on the subsequent polymerisation of the backbone. Our results demonstrate that modification with CS occurs by default and must be overridden by EXTL3 to produce HS
Mechanism for cross-linking polychloroprene with ethylene thiourea and zinc oxide
An investigation into the mechanism by which ethylene thiourea (ETU) cross-links polychloroprene (CR) in combination with zinc oxide (ZnO) was undertaken. This was achieved through an examination of the mechanisms of crosslinking CR with ETU and ZnO separately and in unison. Spectroscopic and physical characterization techniques were employed to probe the cross-linking mechanisms of CRusing other standard rubber accelerators and model compounds with analogous structures and functionalities to ETU. These investigations have resulted in the proposal of a new mechanism by which ETU and ZnO can synergistically cross-link CR, in addition to providing new evidence to support concomitant mechanisms already published for cross-linking CR
Visualising high-dimensional Pareto relationships in two-dimensional scatterplots
Copyright © 2013 Springer-Verlag Berlin Heidelberg. The final publication is availablevia the DOI in this recordBook title: Evolutionary Multi-Criterion Optimization7th International Conference on Evolutionary Multi-Criterion Optimization (EMO 2013), Sheffield, UK, March 19-22, 2013The codebase for this paper is available at https://github.com/fieldsend/emo_2013_vizIn this paper two novel methods for projecting high dimensional data into two dimensions for visualisation are introduced, which aim to limit the loss of dominance and Pareto shell relationships between solutions to multi-objective optimisation problems. It has already been shown that, in general, it is impossible to completely preserve the dominance relationship when mapping from a higher to a lower dimension – however, approaches that attempt this projection with minimal loss of dominance information are useful for a number of reasons. (1) They may represent the data to the user of a multi-objective optimisation problem in an intuitive fashion, (2) they may help provide insights into the relationships between solutions which are not immediately apparent through other visualisation methods, and (3) they may offer a useful visual medium for interactive optimisation. We are concerned here with examining (1) and (2), and developing relatively rapid methods to achieve visualisations, rather than generating an entirely new search/optimisation problem which has to be solved to achieve the visualisation– which may prove infeasible in an interactive environment for real time use. Results are presented on randomly generated data, and the search population of an optimiser as it progresses. Structural insights into the evolution of a set-based optimiser that can be derived from this visualisation are also discussed
Spin Torque Generated by Valley Hall Effect in WSe2
Monolayer transition metal dichalcogenides are promising materials for
spintronics due to their robust spin-valley locked valence states, enabling
efficient charge-to-spin conversion via valley Hall effect with non-equilibrium
spins possessing long spin diffusion lengths of hundreds of nanometers. In this
work, we show that the injection of a pure valley current, induced by valley
Hall effect in a WSe2 monolayer, imparts a spin torque on the magnetization of
an overlaid Fe or CoFe in a tunneling structure. The torque efficiency is found
to be comparable to that in conventional perpendicular magnetic tunnel
junctions and can be further optimized with valley Hall angle in WSe2. The
valley nature of the spin torque gives rise to out-of-plane damping-like
torques in a current-in-plane configuration, vanishing charge transport
perpendicular-to-the-plane as well as torque efficiency tunable through gating
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Disparities in selective referral for cancer surgeries: implications for the current healthcare delivery system
Objectives: Among considerable efforts to improve quality of surgical care, expedited measures such as a selective referral to high-volume institutions have been advocated. Our objective was to examine whether racial, insurance and/or socioeconomic disparities exist in the use of high-volume hospitals for complex surgical oncological procedures within the USA. Design, setting and participants Patients undergoing colectomy, cystectomy, oesophagectomy, gastrectomy, hysterectomy, lung resection, pancreatectomy or prostatectomy were identified retrospectively, using the Nationwide Inpatient Sample, between years 1999 and 2009. This resulted in a weighted estimate of 2 508 916 patients. Primary outcome measures Distribution of patients according to race, insurance and income characteristics was examined according to low-volume and high-volume hospitals (highest 20% of patients according to the procedure-specific mean annual volume). Generalised linear regression models for prediction of access to high-volume hospitals were performed. Results: Insurance providers and county income levels varied differently according to patients’ race. Most Caucasians resided in wealthier counties, regardless of insurance types (private/Medicare), while most African Americans resided in less wealthy counties (≤45 000) were more likely to receive surgery at high-volume hospitals, even after adjustment for all other patient-specific characteristics. Depending on the procedure, some disparities were more prominent, but the overall trend suggests a collinear effect for race, insurance type and county income levels. Conclusions: Prevailing disparities exist according to several patient and sociodemographic characteristics for utilisation of high-volume hospitals. Efforts should be made to directly reduce such disparities and ensure equal healthcare delivery
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