168 research outputs found

    Efficient Simulation Of Complex Fenestration Systems In Heat Balance Room Models

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    The solar, longwave, and convective interactions between a window, its shading attachments and its surroundings constitute a complicated coupled heat balance problem that can entail significant computational intensity to simulate in detail. A novel approach represents the fenestration system using several indices of merit – most notably the U-factor and a cross-coupling coefficient. CPU time is reduced without forfeiting features such as the ability to distinguish between air and mean radiant temperatures. The required indices of merit are obtained using thermal network theory and can safely be re-evaluated much less frequently than each time-step, or they can be revised as needed in response to changes in sun angle or shade geometry (e.g., blind slat adjustment). This method has been used to integrate the ASHWAT fenestration model with the California Simulation Engine, a detailed residential model. ASHWAT supports many combinations of glazing and shading layers separated by arbitrary fill gases or by gaps open to outdoor or indoor air. This implementation demonstrates a method that offers generality and detail while providing the input simplicity and computational speed required for practicality.American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) || Natural Science and Engineering Research Council (NSERC) || California Energy Commission (CEC) || Pacific Gas & Electric Company || Southern California Edison || Sempra Utilitie

    Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

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    Several model plants are known to respond to bacterial quorum sensing molecules with altered root growth and gene expression patterns and induced resistance to plant pathogens. These compounds may represent novel elicitors that could be applied as seed primers to enhance cereal crop resistance to pathogens and abiotic stress and to improve yields. We investigated whether the acyl-homoserine lactone N-hexanoyl-L-homoserine lactone (C6-HSL) impacted winter wheat (Triticum aestivum L.) seed germination, plant development and productivity, using two Ukrainian varieties, Volodarka and Yatran 60, in both in vitro experiments and field trials. In vitro germination experiments indicated that C6-HSL seed priming had a small but significant positive impact on germination levels (1.2x increase, p < 0.0001), coleoptile and radicle development (1.4x increase, p < 0.0001). Field trials over two growing seasons (2015-16 and 2016-17) also demonstrated significant improvements in biomass at the tillering stage (1.4x increase, p < 0.0001), and crop structure and productivity at maturity including grain yield (1.4 – 1.5x increase, p < 0.0007) and quality (1.3x increase in good grain, p < 0.0001). In some cases variety effects were observed (p ≤ 0.05) suggesting that the effect of C6-HSL seed priming might depend on plant genetics, and some benefits of priming were also evident in F1 plants grown from seeds collected the previous season (p ≤ 0.05). These field-scale findings suggest that bacterial acyl-homoserine lactones such as C6-HSL could be used to improve cereal crop growth and yield and reduce reliance on fungicides and fertilisers to combat pathogens and stress

    Some properties of the k-dimensional Lyness' map

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    This paper is devoted to study some properties of the k-dimensional Lyness' map. Our main result presentes a rational vector field that gives a Lie symmetry for F. This vector field is used, for k less or equal to 5 to give information about the nature of the invariant sets under F. When k is odd, we also present a new (as far as we know) first integral for F^2 which allows to deduce in a very simple way several properties of the dynamical system generated by F. In particular for this case we prove that, except on a given codimension one algebraic set, none of the positive initial conditions can be a periodic point of odd period.Comment: 22 pages; 3 figure

    Создание облачной виртуальной образовательной среды электронного обучения

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    E-learning creates and continues to actively develop new type of learning due to the organization of the educational process, typical for the third stage of development of the educational institutions of mankind. Creating cloud-based virtual educational enviroment is an example of creating a model for understanding the problems of analysis and design of e-learning.Электронное обучение (e-learning) создает и продолжает активно развивать новый тип обучения благодаря организации образовательного процесса, типичного для третьего этапа развития учебных заведений человечества. Создание облачной виртуальной образовательной среды является примером создания модели для понимания проблемы анализа и проектирования электронного обучения

    Evidence for Shared Cognitive Processing of Pitch in Music and Language

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    Language and music epitomize the complex representational and computational capacities of the human mind. Strikingly similar in their structural and expressive features, a longstanding question is whether the perceptual and cognitive mechanisms underlying these abilities are shared or distinct – either from each other or from other mental processes. One prominent feature shared between language and music is signal encoding using pitch, conveying pragmatics and semantics in language and melody in music. We investigated how pitch processing is shared between language and music by measuring consistency in individual differences in pitch perception across language, music, and three control conditions intended to assess basic sensory and domain-general cognitive processes. Individuals’ pitch perception abilities in language and music were most strongly related, even after accounting for performance in all control conditions. These results provide behavioral evidence, based on patterns of individual differences, that is consistent with the hypothesis that cognitive mechanisms for pitch processing may be shared between language and music.National Science Foundation (U.S.). Graduate Research Fellowship ProgramEunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.) (Grant 5K99HD057522

    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-(3′-5′)-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 ц-ди-ГМФ и возможного чувства кворума у Pseudomonas fluorescens SBW 25: связь между внутри и межклеточной регуляцией способствует кооперативному поведению в сообществе и формированию биоплёнкиУспешность бактериальной колонизации сложных экониш требует индивидуального ответа на изменения условий на микроуровне равно как и кооперации на уровне сообщества для продукции таких крупно масштабных структур как биоплёнки. Координация индивидуальных ответ ов и ответов сообщества может быть достигнута путем связывания внутриклеточных сенсорных и регуляторных систем, опосредуемых бис-(3',5')-циклическим димерным гуанозинмонофосфатом (ц-ди-ГМФ) и другими соединениями индивидуумов с межклеточной регуляцией - чувством кворума (ЧК), контролирующем популяци ю. Накапливается всё больше доказательств того, что формирование биопленки многими псевдомонадами регулируется как внутри клеточными, так и меж клеточными регуляторными системами, хотя в случае модельной Pseudomonas fluorescens SBW25 Wrinkly Spreader, у которой мутации, повышающ ие уровни ц-ди-ГМФ, приводят к созданию прочной целлюлозной биоплёнки на границе раздела фаз воздух-жидкость, не было обнаружено ни ка кого свидетельства вовлечения кворум-зависимой регуляции. Однако наш недавний обзор генома P. fluorescens SBW25 выявил потенциальный ЧК-зависимый регуляторный пу ть и другие ЧК-зависимые гены, связанные с гомеостазом ц-ди-ГМФ, а молекулы ЧК-сигналинга были идентифицированы в культуре. Эти данные свидетельствуют о возможной связи между ц-ди-ГМФ-регуляцией и ЧК у P. fluorescens SBW25, что позволяет более сложный и гибкий контроль над продукцией целлюлозы и образовани ем биопленки при колонизации почв и экониш, aссоциированных с растениям и, - естественными средами обитания P. fluorescens SBW25

    In situ phytoplankton distributions in the Amundsen Sea Polynya measured by autonomous gliders

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    The Amundsen Sea Polynya is characterized by large phytoplankton blooms, which makes this region disproportionately important relative to its size for the biogeochemistry of the Southern Ocean. In situ data on phytoplankton are limited, which is problematic given recent reports of sustained change in the Amundsen Sea. During two field expeditions to the Amundsen Sea during austral summer 2010-2011 and 2014, we collected physical and bio-optical data from ships and autonomous underwater gliders. Gliders documented large phytoplankton blooms associated with Antarctic Surface Waters with low salinity surface water and shallow upper mixed layers (\u3c 50 m). High biomass was not always associated with a specific water mass, suggesting the importance of upper mixed depth and light in influencing phytoplankton biomass. Spectral optical backscatter and ship pigment data suggested that the composition of phytoplankton was spatially heterogeneous, with the large blooms dominated by Phaeocystis and non-bloom waters dominated by diatoms. Phytoplankton growth rates estimated from field data (\u3c = 0.10 day(-1)) were at the lower end of the range measured during ship-based incubations, reflecting both in situ nutrient and light limitations. In the bloom waters, phytoplankton biomass was high throughout the 50-m thick upper mixed layer. Those biomass levels, along with the presence of colored dissolved organic matter and detritus, resulted in a euphotic zone that was often \u3c 10 m deep. The net result was that the majority of phytoplankton were light-limited, suggesting that mixing rates within the upper mixed layer were critical to determining the overall productivity; however, regional productivity will ultimately be controlled by water column stability and the depth of the upper mixed layer, which may be enhanced with continued ice melt in the Amundsen Sea Polynya

    Effect of polymeric biocide polyhexamethylene guanidine hydrochloride on morpho-physiological and biochemical parameters of wheat seedlings under copper stress

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    Aim. To study the effect of polymeric biocide polyhexamethylene guanidine hydrochloride (PHMG-Cl) on morphophysiological and biochemical parameters of wheat seedlings in the presence of toxic concentration of copper ions. Methods. The growth-stimulating activity of PHMG-Cl in pure state, as well as in the presence of elevated concentrations of copper ions was studied by phytotesting method using wheat seed as a test culture. Physico-chemical interaction between PHMG-Cl and CuSO4 in water solutions was studied by spectrophotometry. Results. Wheat seed treatment with water solutions of polymeric biocide PHMG-Cl in the concentration range of 0.01–0.1 % causes an increase in the length of roots and shoots by over 50 % after 7 days of incubation. The concentration of PHMG-Cl of 1 % was found to have a depressive effect on growth characteristics of the tested plants. This fact indicates that the phytotoxicity of PHMG-Cl is at least two orders of magnitude lower compared with a common pesticide copper sulfate. Thus, wheat seed soaking in 200 μM (0.003 %) water solution of copper sulfate causes reduced length of shoots and roots (by 65 and 34 %, respectively), as well as reduced weight of shoots (by 20 %) and roots (by 74 %) The analysis of green mass showed signifi cantly reduced content of carotenoids (by 26 %) and water soluble fl avonoids (by 37 %), as well as chlorophyll a/b ratio (by 18 %) that indicates decreased plant metabolic activity. However, the toxic effect of copper sulfate ions signifi cantly diminished in the presence of PHMG-Cl (0.01 %). Thus, the length of shoots and roots was found to increase by 24 and 64 %, respectively, compared to the samples treated with CuSO4. Moreover, the content of pigments and fl avonoids in the green mass of seedlings reached the level of control samples. The results of spectrophotometric studies indicate the absence of physico-chemical interaction between PHMG-Cl and copper sulfate in water solutions. Conclusions. The polymeric biocide PHMG-Cl effectively stimulates growth and development of wheat seedlings in the concentration range of its water solutions of 0.01–0.1 %. In the presence of toxic copper sulfate concentration, PHMG-Cl does not possess the growth stimulating activity. However, the polymeric biocide signifi cantly improves copper stress resistance of plants, and normalizes their morpho-physiological indicators, photosynthetic characteristics and secondary exchange
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