16,827 research outputs found

    The Research Space: using the career paths of scholars to predict the evolution of the research output of individuals, institutions, and nations

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    In recent years scholars have built maps of science by connecting the academic fields that cite each other, are cited together, or that cite a similar literature. But since scholars cannot always publish in the fields they cite, or that cite them, these science maps are only rough proxies for the potential of a scholar, organization, or country, to enter a new academic field. Here we use a large dataset of scholarly publications disambiguated at the individual level to create a map of science-or research space-where links connect pairs of fields based on the probability that an individual has published in both of them. We find that the research space is a significantly more accurate predictor of the fields that individuals and organizations will enter in the future than citation based science maps. At the country level, however, the research space and citations based science maps are equally accurate. These findings show that data on career trajectories-the set of fields that individuals have previously published in-provide more accurate predictors of future research output for more focalized units-such as individuals or organizations-than citation based science maps

    Definition of a near real time microbiological monitor for space vehicles

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    Efforts to identify the ideal candidate to serve as the biological monitor on the space station Freedom are discussed. The literature review, the evaluation scheme, descriptions of candidate monitors, experimental studies, test beds, and culture techniques are discussed. Particular attention is given to descriptions of five candidate monitors or monitoring techniques: laser light scattering, primary fluorescence, secondary fluorescence, the volatile product detector, and the surface acoustic wave detector

    Digital Image Analysis of Actinomycetes Colonies as a Potential Aid for Rapid Taxonomic Identification

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    High frequency isolation of actinomycetes poses a challenge for the taxonomists hence simple and rapid identification methods are required. Our work to catalogue biodiversity of actinomycetes of Goa yielded several distinct morphotypes. After their tentative identification, the feasibility to distinguish these using digital image analyses (DIA) was explored. Digital images of wild colony morphotypes were processed using public domain SCION image analysis software. DIA revealed some intricate digital characters. A combination of these with standard morphological and microscopic characters could be potentially useful for preparing a digital identification key of the actinomycetes strains with potential application in rapid taxonomic identification

    Recent progress in the identification and determination of freshwater phytoplankton in the natural environment

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    The biomass of the phytoplankton and its composition is one of the most important factors in water quality control. Determination of the phytoplankton assemblage is usually done by microscopic analysis (UtermΓΆhl's method). Quantitative estimations of the biovolume, by cell counting and cell size measurements, are time-consuming and normally are not done in routine water quality control. Several alternatives have been tried: computer-based image analysis, spectral fluorescence signatures, flow cytometry and pigment fingerprinting aided by high performance liquid chromatography (HPLC). The latter method is based on the fact that each major algal group of taxa contains a specific carotenoid which can be used for identification and relative quantification of the taxa in the total assemblage. This article gives a brief comparative introduction to the different techniques available and presents some recent results obtained by HPLC-based pigment fingerprinting, applied to three lakes of different trophic status. The results show that this technique yields reliable results from different lake types and is a powerful tool for studying the distribution pattern of the phytoplankton community in relation to water depth. However, some restrictions should be taken into account for the interpretation of routine data

    Microbiological influences on fracture surfaces of intact mudstone and the implications for geological disposal of radioactive waste

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    The significance of the potential impacts of microbial activity on the transport properties of host rocks for geological repositories is an area of active research. Most recent work has focused on granitic environments. This paper describes pilot studies investigating changes in transport properties that are produced by microbial activity in sedimentary rock environments in northern Japan. For the first time, these short experiments (39 days maximum) have shown that the denitrifying bacteria, Pseudomonas denitrificans, can survive and thrive when injected into flow-through column experiments containing fractured diatomaceous mudstone and synthetic groundwater under pressurized conditions. Although there were few significant changes in the fluid chemistry, changes in the permeability of the biotic column, which can be explained by the observed biofilm formation, were quantitatively monitored. These same methodologies could also be adapted to obtain information from cores originating from a variety of geological environments including oil reservoirs, aquifers and toxic waste disposal sites to provide an understanding of the impact of microbial activity on the transport of a range of solutes, such as groundwater contaminants and gases (e.g. injected carbon dioxide)

    Intracellular proteome expression during 4-n-nonylphenol biodegradation by the filamentous fungus Metarhizium robertsii

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    4-n-nonylphenol (4-n-NP) is an endocrine disrupting compound (EDC); pollutants that cause serious disturbances in the environment. This study shows the degradation pathway and initial proteome analysis in cultures of a fungus that actively degrades 4-n-NP, Metarhizium robertsii. The research revealed the presence of 14 4-n-NP metabolites formed as a result of the oxidation of the alkyl chain and benzene ring, which leads to the complete decomposition of the compound. Based on the trend and quantitative analysis of the formation of 4-n-NP derivatives, the best conditions for proteome analysis were established. The data collected allowed the formulation of an explanation of the microorganism's strategy towards the removal of 4-n-NP. The main groups of proteins engaged in the removal of the xenobiotic are: oxidation-reduction systems related to nitroreductase-like proteins, ROS defense systems (peroxiredoxin and superoxide dismutase), the TCA cycle and energy-related systems. Principal components analysis was applied to unidentified proteins, resulting in the formulation of three subgroups and initial classification of these proteins

    Real deal or no deal? A comparative analysis of raw milk cheese regulation in Australia and France

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    Australia’s regulatory framework has resulted in the standardisation of cheese production based on pasteurisation. Up until early 2015, regulations effectively prohibited raw milk cheese-making in Australia and thus stifled artisanal on-farm production. Although the introduction of Food Standards Australia New Zealand Standard 4.2.4 has allowed the production of certain hard, low-moisture raw milk cheeses, the new standard is rigid and does not encourage new entrants into the emerging raw milk cheese consumer market. This article compares the Australian system with the French raw milk cheese regulation and production system, and argues that its approach in encouraging and supporting small farmhouse artisanal traditional raw milk cheese is beneficial to both producer and consumer, and has not resulted in any significant health risks. The Australian approach amounts to a missed opportunity to encourage the emergence of a value-added industry with local and export potential, and is at odds with important movements in food policy, such as recognition of the value of localism and terroir

    Examining c-di-GMP and possible quorum sensing regulation in Pseudomonas fluorescens SBW25:links between intra and inter-cellular regulation benefits community cooperative activities such as biofilm formation

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    Bacterial success in colonizing complex environments requires individual response to micro-scale conditions as well as community-level cooperation to produce large-scale structures such as biofilms. Connecting individual and community responses could be achieved by linking the intracellular sensory and regulatory systems mediated by bis-(3β€²-5β€²)-cyclic dimeric guanosine monophosphate (c-di-GMP) and other compounds of individuals with intercellular quorum sensing (QS) regulation controlling populations. There is growing evidence to suggest that biofilm formation by many pseudomonads is regulated by both intra and intercellular systems, though in the case of the model Pseudomonas fluorescens SBW25 Wrinkly Spreader in which mutations increasing c-di-GMP levels result in the production of a robust cellulose-based air-liquid interface biofilm, no evidence for the involvement of QS regulation has been reported. However, our recent review of the P. fluorescens SBW25 genome has identified a potential QS regulatory pathway and other QS–associated genes linked to c-di-GMP homeostasis, and QS signal molecules have also been identified in culture supernatants. These findings suggest a possible link between c-di-GMP and QS regulation in P. fluorescens SBW25 which might allow a more sophisticated and responsive control of cellulose production and biofilm formation when colonising the soil and plant-associated environments P. fluorescens SBW25 normally inhabits.Анализ Ρ†-Π΄ΠΈ-Π“ΠœΠ€ ΠΈ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΠ³ΠΎ чувства ΠΊΠ²ΠΎΡ€ΡƒΠΌΠ° Ρƒ Pseudomonas fluorescens SBW 25: связь ΠΌΠ΅ΠΆΠ΄Ρƒ Π²Π½ΡƒΡ‚Ρ€ΠΈ ΠΈ ΠΌΠ΅ΠΆΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½ΠΎΠΉ рСгуляциСй способствуСт ΠΊΠΎΠΎΠΏΠ΅Ρ€Π°Ρ‚ΠΈΠ²Π½ΠΎΠΌΡƒ повСдСнию Π² сообщСствС ΠΈ Ρ„ΠΎΡ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½ΠΈΡŽ Π±ΠΈΠΎΠΏΠ»Ρ‘Π½ΠΊΠΈΠ£ΡΠΏΠ΅ΡˆΠ½ΠΎΡΡ‚ΡŒ Π±Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ°Π»ΡŒΠ½ΠΎΠΉ ΠΊΠΎΠ»ΠΎΠ½ΠΈΠ·Π°Ρ†ΠΈΠΈ слоТных экониш Ρ‚Ρ€Π΅Π±ΡƒΠ΅Ρ‚ ΠΈΠ½Π΄ΠΈΠ²ΠΈΠ΄ΡƒΠ°Π»ΡŒΠ½ΠΎΠ³ΠΎ ΠΎΡ‚Π²Π΅Ρ‚Π° Π½Π° измСнСния условий Π½Π° ΠΌΠΈΠΊΡ€ΠΎΡƒΡ€ΠΎΠ²Π½Π΅ Ρ€Π°Π²Π½ΠΎ ΠΊΠ°ΠΊ ΠΈ ΠΊΠΎΠΎΠΏΠ΅Ρ€Π°Ρ†ΠΈΠΈ Π½Π° ΡƒΡ€ΠΎΠ²Π½Π΅ сообщСства для ΠΏΡ€ΠΎΠ΄ΡƒΠΊΡ†ΠΈΠΈ Ρ‚Π°ΠΊΠΈΡ… ΠΊΡ€ΡƒΠΏΠ½ΠΎ ΠΌΠ°ΡΡˆΡ‚Π°Π±Π½Ρ‹Ρ… структур ΠΊΠ°ΠΊ Π±ΠΈΠΎΠΏΠ»Ρ‘Π½ΠΊΠΈ. ΠšΠΎΠΎΡ€Π΄ΠΈΠ½Π°Ρ†ΠΈΡ ΠΈΠ½Π΄ΠΈΠ²ΠΈΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… ΠΎΡ‚Π²Π΅Ρ‚ ΠΎΠ² ΠΈ ΠΎΡ‚Π²Π΅Ρ‚ΠΎΠ² сообщСства ΠΌΠΎΠΆΠ΅Ρ‚ Π±Ρ‹Ρ‚ΡŒ достигнута ΠΏΡƒΡ‚Π΅ΠΌ связывания Π²Π½ΡƒΡ‚Ρ€ΠΈΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½Ρ‹Ρ… сСнсорных ΠΈ рСгуляторных систСм, опосрСдуСмых бис-(3',5')-цикличСским Π΄ΠΈΠΌΠ΅Ρ€Π½Ρ‹ΠΌ гуанозинмонофосфатом (Ρ†-Π΄ΠΈ-Π“ΠœΠ€) ΠΈ Π΄Ρ€ΡƒΠ³ΠΈΠΌΠΈ соСдинСниями ΠΈΠ½Π΄ΠΈΠ²ΠΈΠ΄ΡƒΡƒΠΌΠΎΠ² с ΠΌΠ΅ΠΆΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½ΠΎΠΉ рСгуляциСй - чувством ΠΊΠ²ΠΎΡ€ΡƒΠΌΠ° (ЧК), ΠΊΠΎΠ½Ρ‚Ρ€ΠΎΠ»ΠΈΡ€ΡƒΡŽΡ‰Π΅ΠΌ популяци ю. НакапливаСтся всё большС Π΄ΠΎΠΊΠ°Π·Π°Ρ‚Π΅Π»ΡŒΡΡ‚Π² Ρ‚ΠΎΠ³ΠΎ, Ρ‡Ρ‚ΠΎ Ρ„ΠΎΡ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½ΠΈΠ΅ Π±ΠΈΠΎΠΏΠ»Π΅Π½ΠΊΠΈ ΠΌΠ½ΠΎΠ³ΠΈΠΌΠΈ псСвдомонадами рСгулируСтся ΠΊΠ°ΠΊ Π²Π½ΡƒΡ‚Ρ€ΠΈ ΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½Ρ‹ΠΌΠΈ, Ρ‚Π°ΠΊ ΠΈ ΠΌΠ΅ΠΆ ΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½Ρ‹ΠΌΠΈ рСгуляторными систСмами, хотя Π² случаС модСльной Pseudomonas fluorescens SBW25 Wrinkly Spreader, Ρƒ ΠΊΠΎΡ‚ΠΎΡ€ΠΎΠΉ ΠΌΡƒΡ‚Π°Ρ†ΠΈΠΈ, ΠΏΠΎΠ²Ρ‹ΡˆΠ°ΡŽΡ‰ ΠΈΠ΅ ΡƒΡ€ΠΎΠ²Π½ΠΈ Ρ†-Π΄ΠΈ-Π“ΠœΠ€, приводят ΠΊ созданию ΠΏΡ€ΠΎΡ‡Π½ΠΎΠΉ Ρ†Π΅Π»Π»ΡŽΠ»ΠΎΠ·Π½ΠΎΠΉ Π±ΠΈΠΎΠΏΠ»Ρ‘Π½ΠΊΠΈ Π½Π° Π³Ρ€Π°Π½ΠΈΡ†Π΅ Ρ€Π°Π·Π΄Π΅Π»Π° Ρ„Π°Π· Π²ΠΎΠ·Π΄ΡƒΡ…-ΠΆΠΈΠ΄ΠΊΠΎΡΡ‚ΡŒ, Π½Π΅ Π±Ρ‹Π»ΠΎ ΠΎΠ±Π½Π°Ρ€ΡƒΠΆΠ΅Π½ΠΎ Π½ΠΈ ΠΊΠ° ΠΊΠΎΠ³ΠΎ ΡΠ²ΠΈΠ΄Π΅Ρ‚Π΅Π»ΡŒΡΡ‚Π²Π° вовлСчСния ΠΊΠ²ΠΎΡ€ΡƒΠΌ-зависимой рСгуляции. Однако наш Π½Π΅Π΄Π°Π²Π½ΠΈΠΉ ΠΎΠ±Π·ΠΎΡ€ Π³Π΅Π½ΠΎΠΌΠ° P. fluorescens SBW25 выявил ΠΏΠΎΡ‚Π΅Π½Ρ†ΠΈΠ°Π»ΡŒΠ½Ρ‹ΠΉ ЧК-зависимый рСгуляторный ΠΏΡƒ Ρ‚ΡŒ ΠΈ Π΄Ρ€ΡƒΠ³ΠΈΠ΅ ЧК-зависимыС Π³Π΅Π½Ρ‹, связанныС с гомСостазом Ρ†-Π΄ΠΈ-Π“ΠœΠ€, Π° ΠΌΠΎΠ»Π΅ΠΊΡƒΠ»Ρ‹ ЧК-сигналинга Π±Ρ‹Π»ΠΈ ΠΈΠ΄Π΅Π½Ρ‚ΠΈΡ„ΠΈΡ†ΠΈΡ€ΠΎΠ²Π°Π½Ρ‹ Π² ΠΊΡƒΠ»ΡŒΡ‚ΡƒΡ€Π΅. Π­Ρ‚ΠΈ Π΄Π°Π½Π½Ρ‹Π΅ ΡΠ²ΠΈΠ΄Π΅Ρ‚Π΅Π»ΡŒΡΡ‚Π²ΡƒΡŽΡ‚ ΠΎ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΠΉ связи ΠΌΠ΅ΠΆΠ΄Ρƒ Ρ†-Π΄ΠΈ-Π“ΠœΠ€-рСгуляциСй ΠΈ ЧК Ρƒ P. fluorescens SBW25, Ρ‡Ρ‚ΠΎ позволяСт Π±ΠΎΠ»Π΅Π΅ слоТный ΠΈ Π³ΠΈΠ±ΠΊΠΈΠΉ ΠΊΠΎΠ½Ρ‚Ρ€ΠΎΠ»ΡŒ Π½Π°Π΄ ΠΏΡ€ΠΎΠ΄ΡƒΠΊΡ†ΠΈΠ΅ΠΉ Ρ†Π΅Π»Π»ΡŽΠ»ΠΎΠ·Ρ‹ ΠΈ ΠΎΠ±Ρ€Π°Π·ΠΎΠ²Π°Π½ΠΈ Π΅ΠΌ Π±ΠΈΠΎΠΏΠ»Π΅Π½ΠΊΠΈ ΠΏΡ€ΠΈ ΠΊΠΎΠ»ΠΎΠ½ΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΏΠΎΡ‡Π² ΠΈ экониш, aссоциированных с растСниям ΠΈ, - СстСствСнными срСдами обитания P. fluorescens SBW25

    Characterization of CMR5c and CMR12a, novel fluorescent Pseudomonas strains from the cocoyam rhizosphere with biocontrol activity

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    Aim: To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol of cocoyam root rot caused by Pythium myriotylum. Material and Results: Forty pseudomonads were isolated from the rhizosphere of healthy white and red cocoyam plants appearing in natural, heavily infested fields in Cameroon. In vitro tests demonstrated that Py. myriotylum antagonists could be retrieved from the red cocoyam rhizosphere. Except for one isolate, all antagonistic isolates produced phenazines. Results from whole-cell protein profiling showed that the antagonistic isolates are different from other isolated pseudomonads, while BOX-PCR revealed high genomic similarity among them. 16S rDNA sequencing of two representative strains within this group of antagonists confirmed their relatively low similarity with validly described Pseudomonas species. These antagonists are thus provisionally labelled as unidentified Pseudomonas strains. Among the antagonists, Pseudomonas CMR5c and CMR12a were selected because of their combined production of phenazines and biosurfactants. For strain CMR5c also, production of pyrrolnitrin and pyoluteorin was demonstrated. Both CMR5c and CMR12a showed excellent in vivo biocontrol activity against Py. myriotylum to a similar level as Ps. aeruginosa PNA1. Conclusion: Pseudomonas CMR5c and CMR12a were identified as novel and promising biocontrol agents of Py. myriotylum on cocoyam, producing an arsenal of antagonistic metabolites. Significance and Impact of the Study: Present study reports the identification of two newly isolated fluorescent Pseudomonas strains that can replace the opportunistic human pathogen Ps. aeruginosa PNA1 in the biocontrol of cocoyam root rot and could be taken into account for the suppression of many plant pathogens
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