27,092 research outputs found

    Development of inorganic non-flammable spacecraft potting, encapsulating, and conformal coating compounds Final report

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    Development of inorganic nonflammable potting, encapsulating, and coating compounds for spacecraf

    Organic Farming Development and Agricultural Institutions in Europe: A Study of Six Countries

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    Cooperation between general agricultural institutions and the organisation of the organic farming sector are key factors for the development of organic farming. This study analyses the relationships of organic farming organisations with other farmers' organisations, agencies of agricultural policy and food market firms in six European countries. On this basis it identifies a path for successful development of organic farming which is adaptable to the special conditions of all European countries. This book presents the most systematic and in-depth comparison of the dynamics of organic farming development to date, providing concrete suggestions for a line of action for everyone with an interest in developing organic farming

    A study to explore the use of orbital remote sensing to determine native arid plant distribution

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    The author has identified the following significant results. It is possible to determine, from ERTS imagery, native arid plant distribution. Using techniques of multispectral masking and extensive fieldwork, three native vegetation communities were defined and mapped in the Avra Valley study area. A map was made of the Yuma area with the aid of ground truth correlations between areas of desert pavement visible on ERTS images and unique vegetation types. With the exception of the Yuma soil-vegetation correlation phenomena, only very gross differentiations of desert vegetation communities can be made from ERTS data. Vegetation communities with obvious vegetation density differences such as saguaro-paloverde, creosote bush, and riparian vegetation can be separated on the Avra Valley imagery while more similar communities such as creosote bush and saltbush could not be differentiated. It is suggested that large differences in vegetation density are needed before the signatures of two different vegetation types can be differentiated on ERTS imagery. This is due to the relatively insignificant contribution of vegetation to the total radiometric signature of a given desert scene. Where more detailed information concerning the vegetation of arid regions is required, large scale imagery is appropriate

    Virtual acoustics displays

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    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events

    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

    Elevating crop disease resistance with cloned genes

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    Essentially all plant species exhibit heritable genetic variation for resistance to a variety of plant diseases caused by fungi, bacteria, oomycetes or viruses. Disease losses in crop monocultures are already significant, and would be greater but for applications of disease-controlling agrichemicals. For sustainable intensification of crop production, we argue that disease control should as far as possible be achieved using genetics rather than using costly recurrent chemical sprays. The latter imply CO2 emissions from diesel fuel and potential soil compaction from tractor journeys. Great progress has been made in the past 25 years in our understanding of the molecular basis of plant disease resistance mechanisms, and of how pathogens circumvent them. These insights can inform more sophisticated approaches to elevating disease resistance in crops that help us tip the evolutionary balance in favour of the crop and away from the pathogen. We illustrate this theme with an account of a genetically modified (GM) blight-resistant potato trial in Norwich, using the Rpi-vnt1.1 gene isolated from a wild relative of potato, Solanum venturii, and introduced by GM methods into the potato variety Desiree

    Resonant forcing of select degrees of freedom of multidimensional chaotic map dynamics

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    We study resonances of multidimensional chaotic map dynamics. We use the calculus of variations to determine the additive forcing function that induces the largest response, that is, the greatest deviation from the unperturbed dynamics. We include the additional constraint that only select degrees of freedom be forced, corresponding to a very general class of problems in which not all of the degrees of freedom in an experimental system are accessible to forcing. We find that certain Lagrange multipliers take on a fundamental physical role as the efficiency of the forcing function and the effective forcing experienced by the degrees of freedom which are not forced directly. Furthermore, we find that the product of the displacement of nearby trajectories and the effective total forcing function is a conserved quantity. We demonstrate the efficacy of this methodology with several examples.Comment: 11 pages, 3 figure

    The Y-Band at 1.035 um: Photometric Calibration and the Dwarf Stellar/Sub-Stellar Color Sequence

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    We define and characterize a photometric bandpass (called "Y") that is centered at 1.035 um, in between the traditionally classified ``optical'' and ``infrared'' spectral regimes. We present Y magnitudes and Y-H and Y-K colors for a sample consisting mostly of photometric and spectral standards, spanning the spectral type range sdO to T5V. Deep molecular absorption features in the near-infrared spectra of extremely cool objects are such that the Y-H and Y-K colors grow rapidly with advancing spectral type especially from late M through mid L, substantially more rapidly than J-H or H-K which span a smaller total dynamic range. Consistent with other near-infrared colors, however, Y-H and Y-K colors turn blueward in the L6-L8 temperature range with later T-type objects having colors similar to those of warmer M and L stars. Use of the Y-band filter is nonetheless promising for easy identification of low-mass stars and brown dwarfs, especially at young ages. The slope of the interstellar reddening vector within this filter is A_Y = 0.38 x A_V. Reddening moves stars nearly along the YHK dwarf color sequence making it more difficult to distinguish unambiguously very low mass candidate brown dwarf objects from higher mass stars seen, e.g. through the galactic plane or towards star-forming regions. Other diagrams involving the Y-band may be somewhat more discriminating.Comment: accepted at PAS
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