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Sample records for acquisition mechanisms nutrient

  1. Mechanisms of Nutrient Acquisition by Rock Eating Microbes Revealed by Proteomics

    Bryce, C. C.; Martin, S.; LeBihan, T.; Cockell, C.

    2013-12-01

    In nutrient poor terrestrial environments such as fresh lava flows, bioessential elements contained within surrounding rocks can be an important source of nutrients for the microbial community. The role of microbes in the alteration of rock surfaces, driven by this nutrient requirement, is widely accepted and is known to play an important role in CO2 drawdown as well as influencing nutrient flux to the biosphere. There is, however, limited knowledge of the biological processes which facilitate the uptake of bioessential elements from rocks. Using a technique known as 'shotgun' proteomics we have investigated the cellular processes involved in the uptake of iron, calcium and magnesium from fresh basalt in the heavy metal resistant bacterium Cupriavidus metallidurans CH34. Quantitative proteomics allows us to obtain a detailed snapshot of the protein complement of cells. By comparing cultures grown under normal growth conditions to cultures grown with basalt as an alternative iron, calcium or magnesium source, we can highlight proteins which are differentially expressed and therefore important for life in a rocky environment. We observe that the use of rock-bound nutrients induces a complex metabolic response in C.metallidurans which is distinct from the effects observed in the presence of rocks in normal growth medium. This is evidenced, for example, by the upregulation of a number of proteins involved in alternative energy-producing processes such as chemolithotrophy, sulphur oxidation and hydrogen oxidation compared to control cultures. This work has implications for the understanding of how microbes forge a life for themselves from the Earth's crust and highlights the importance of the field of proteomics for the study of life in terrestrial environments.

  2. Comparison of nutrient acquisition in exotic plant species and congeneric natives

    Meisner, A.; Boer, de W.; Verhoeven, K.J.F.; Boschker, H.T.S.; Putten, van der W.H.

    2011-01-01

    1. The ability of exotic plant species to establish and expand in new areas may be enhanced by a relatively high ability to acquire soil nutrients. To test this hypothesis, we predicted that the capacity for nutrient acquisition would be higher in seedlings of exotic species than in seedlings of nat

  3. Comparison of nutrient acquisition in exotic plant species and congeneric natives

    Meisner, A.; De Boer, W.; Verhoeven, K.J.F.; Boschker, H.T.S.; Van der Putten, W.H.

    2011-01-01

    1.The ability of exotic plant species to establish and expand in new areas may be enhanced by a relatively high ability to acquire soil nutrients. To test this hypothesis, we predicted that the capacity for nutrient acquisition would be higher in seedlings of exotic species than in seedlings of nati

  4. Is nitrogen transfer among plants enhanced by contrasting nutrient-acquisition strategies?

    Teste, François P; Veneklaas, Erik J; Dixon, Kingsley W; Lambers, Hans

    2015-01-01

    Nitrogen (N) transfer among plants has been found where at least one plant can fix N2 . In nutrient-poor soils, where plants with contrasting nutrient-acquisition strategies (without N2 fixation) co-occur, it is unclear if N transfer exists and what promotes it. A novel multi-species microcosm pot experiment was conducted to quantify N transfer between arbuscular mycorrhizal (AM), ectomycorrhizal (EM), dual AM/EM, and non-mycorrhizal cluster-rooted plants in nutrient-poor soils with mycorrhizal mesh barriers. We foliar-fed plants with a K(15) NO3 solution to quantify one-way N transfer from 'donor' to 'receiver' plants. We also quantified mycorrhizal colonization and root intermingling. Transfer of N between plants with contrasting nutrient-acquisition strategies occurred at both low and high soil nutrient levels with or without root intermingling. The magnitude of N transfer was relatively high (representing 4% of donor plant N) given the lack of N2 fixation. Receiver plants forming ectomycorrhizas or cluster roots were more enriched compared with AM-only plants. We demonstrate N transfer between plants of contrasting nutrient-acquisition strategies, and a preferential enrichment of cluster-rooted and EM plants compared with AM plants. Nutrient exchanges among plants are potentially important in promoting plant coexistence in nutrient-poor soils. PMID:24811370

  5. Use of fluorescent nanoparticles to investigate nutrient acquisition by developing Eimeria maxima macrogametocytes

    Frölich, Sonja; Wallach, Michael

    2016-01-01

    The enteric disease coccidiosis, caused by the unicellular parasite Eimeria, is a major and reoccurring problem for the poultry industry. While the molecular machinery driving host cell invasion and oocyst wall formation has been well documented in Eimeria, relatively little is known about the host cell modifications which lead to acquisition of nutrients and parasite growth. In order to understand the mechanism(s) by which nutrients are acquired by developing intracellular gametocytes and oocysts, we have performed uptake experiments using polystyrene nanoparticles (NPs) of 40 nm and 100 nm in size, as model NPs typical of organic macromolecules. Cytochalasin D and nocodazole were used to inhibit, respectively, the polymerization of the actin and microtubules. The results indicated that NPs entered the parasite at all stages of macrogametocyte development and early oocyst maturation via an active energy dependent process. Interestingly, the smaller NPs were found throughout the parasite cytoplasm, while the larger NPs were mainly localised to the lumen of large type 1 wall forming body organelles. NP uptake was reduced after microfilament disruption and treatment with nocodazole. These observations suggest that E. maxima parasites utilize at least 2 or more uptake pathways to internalize exogenous material during the sexual stages of development. PMID:27352801

  6. Ectopic expression of amaranth seed storage albumin modulates photoassimilate transport and nutrient acquisition in sweetpotato.

    Shekhar, Shubhendu; Agrawal, Lalit; Mishra, Divya; Buragohain, Alak Kumar; Unnikrishnan, Mullath; Mohan, Chokkappan; Chakraborty, Subhra; Chakraborty, Niranjan

    2016-01-01

    Storage proteins in plants, because of high nutrient value, have been a subject of intensive investigation. These proteins are synthesized de novo in the cytoplasm and transported to the storage organelles where they serve as reservoir of energy and supplement of nitrogen during rapid growth and development. Sweetpotato is the seventh most important food crop worldwide, and has a significant contribution to the source of nutrition, albeit with low protein content. To determine the behaviour of seed storage proteins in non-native system, a seed albumin, AmA1, was overexpressed in sweetpotato with an additional aim of improving nutritional quality of tuber proteins. Introduction of AmA1 imparted an increase in protein and amino acid contents as well as the phytophenols. The proteometabolomics analysis revealed a rebalancing of the proteome, with no significant effects on the global metabolome profile of the transgenic tubers. Additionally, the slower degradation of starch and cellulose in transgenic tubers, led to increased post-harvest durability. Present study provides a new insight into the role of a seed storage protein in the modulation of photoassimilate movement and nutrient acquisition. PMID:27147459

  7. The Wayside Mechanic: An Analysis of Skill Acquisition in Ghana.

    McLaughlin, Stephen Douglas

    This study describes and analyzes the nature of skill acquisition process in one indigenous, informal training system--the apprenticeship of the wayside mechanics workshops in Koforidua, Ghana. Chapter 2 places apprenticeships training in the wider context of artisanship and training. It traces the history of the West African craft shop and its…

  8. Differences in root distribution, nutrient acquisition and nutrient utilization by tropical forage species grown in degraded hillside soil conditions¹

    Arnulfo Gómez-Carabalí

    2010-04-01

    Full Text Available Low nutrient availability, especially phosphorus (P and nitrogen (N supply is the major limitation to forage production in acid infertile soils of the tropics. A field study was conducted at the farm ‘La Esperanza’ located in Mondomo, Department of Cauca, in the coffee growing zone of Colombia. The main objective was to determine differences in root distribution, nutrient (N, P, K, Ca, Mg and S acquisition and nutrient utilization of one C4 forage grass (Brachiaria dictyoneura and two C3 forage legumes (Arachis pintoi and Centrosema macrocarpum grown under two fertilization levels, cultivated either in monoculture or in association and harvested at four different ages.There were no significant differences in root biomass among the grass and legumes and their combinations. The native vegetation had the lowest root biomass; while the introduced grass (B. dictyoneura had the highest root length density among all materials at all depths and ages and the native vegetation had the highest specific root length. As expected, nutrient uptake increased with age and with high fertilization in all species. Centrosema macrocarpun had the highest N and Ca uptake among all plant materials tested. Uptake of P, K and Mg was greater in the grass B. dictyoneura than in the other plant species and combination planting at all ages. On the other hand, the grass had the lowest Ca uptake. The grass and its mixture with the legumes A. pintoi and C. macrocarpun had the highest S uptake. A highly significant (p<0.001correlation was found between root length density (depths 0-10 and 10-20 cm and N and P uptake. Nutrient use efficiency (g of forage produced for g of nutrient uptake increased with age until 38 weeks. At 55 weeks a sharp decline was observed in nutrient use efficiency. N, Ca and P use efficiency values were higher with the grass than with the two legumes tested. K use efficiency was similar among the three species. For Mg and S the grass had the highest

  9. An intelligent data acquisition system for fluid mechanics research

    Cantwell, E. R.; Zilliac, G.; Fukunishi, Y.

    1989-01-01

    This paper describes a novel data acquisition system for use with wind-tunnel probe-based measurements, which incorporates a degree of specific fluid dynamics knowledge into a simple expert system-like control program. The concept was developed with a rudimentary expert system coupled to a probe positioning mechanism operating in a small-scale research wind tunnel. The software consisted of two basic elements, a general-purpose data acquisition system and the rulebased control element to take and analyze data and supplying decisions as to where to measure, how many data points to take, and when to stop. The system was validated in an experiment involving a vortical flow field, showing that it was possible to increase the resolution of the experiment or, alternatively, reduce the total number of data points required, to achieve parity with the results of most conventional data acquisition approaches.

  10. Changes in growth characters and nutrient acquisition of guava (psidium guajava l.) in response to coal ash

    Coal ash management would remain a great concern all over the world. Several studies proposed that there is an ample scope for safe utilization of coal ash as a soil ameliorant that may improve physical, chemical and biological properties of the soil and is a source of readily available plant micro and macro nutrient. With this concept a pot culture experiment was carried out in the eastern ghat high land zone of Odisha, India under open condition in the nursery. Different levels of coal ash and soil mixture were used in different combinations to check their effect on the physio-morphological and biochemical parameters of guava. The study on the effect of varying levels of coal ash on guava revealed that the combination of 50:50 and 25:75 coal ash and soil mixture increased the seed germination, seedling characteristics, biomass, vegetative growth and chlorophyll content of the seedlings. The increase in growth traits was attributed to increase in nutrient acquisition of plants grown under above combinations. On contrary 100% coal ash in the growing medium reduced seed germination, seedling vigour, growth and biomass per plant. The leaf nutrient status of N, P, K, Ca, Mg, S and the micro nutrients Zn, Mn, B, Mo, Fe and Cu were found to be higher in the treatments having higher proportion of coal ash in the growing medium than other treatments and the lowest was recorded in control ( no coal ash). The findings suggest that application of coal ash in certain proportion is beneficial in terms of growth parameters and nutrient acquisition in guava. (author)

  11. Plant nutrient acquisition strategies in tundra species: at which soil depth do species take up their nitrogen?

    Limpens, Juul; Heijmans, Monique; Nauta, Ake; van Huissteden, Corine; van Rijssel, Sophie

    2016-04-01

    The Arctic is warming at unprecedented rates. Increased thawing of permafrost releases nutrients locked up in the previously frozen soils layers, which may initiate shifts in vegetation composition. The direction in which the vegetation shifts will co-determine whether Arctic warming is mitigated or accelerated, making understanding successional trajectories urgent. One of the key factors influencing the competitive relationships between plant species is their access to nutrients, in particularly nitrogen (N). We assessed the depth at which plant species took up N by performing a 15N tracer study, injecting 15(NH4)2SO4 at three depths (5, 15, 20 cm) into the soil in arctic tundra in north-eastern Siberia in July. In addition we explored plant nutrient acquisition strategy by analyzing natural abundances of 15N in leaves. We found that vascular plants took up 15N at all injection depths, irrespective of species, but also that species showed a clear preference for specific soil layers that coincided with their functional group (graminoids, dwarf shrubs, cryptogams). Graminoids took up most 15N at 20 cm depth nearest to the thaw front, with grasses showing a more pronounced preference than sedges. Dwarf shrubs took up most 15N at 5 cm depth, with deciduous shrubs displaying more preference than evergreens. Cryptogams did not take up any of the supplied 15N . The natural 15N abundances confirmed the pattern of nutrient acquisition from deeper soil layers in graminoids and from shallow soil layers in both deciduous and evergreen dwarf shrubs. Our results prove that graminoids and shrubs differ in their N uptake strategies, with graminoids profiting from nutrients released at the thaw front, whereas shrubs forage in the upper soil layers. The above implies that graminoids, grasses in particular, will have a competitive advantage over shrubs as the thaw front proceeds and/or superficial soil layers dry out. Our results suggest that the vertical distribution of nutrients

  12. Nutrient acquisition across a dietary shift: fruit feeding butterflies crave amino acids, nectivores seek salt.

    Ravenscraft, Alison; Boggs, Carol L

    2016-05-01

    Evolutionary dietary shifts have major ecological consequences. One likely consequence is a change in nutrient limitation-some nutrients become more abundant in the diet, others become more scarce. Individuals' behavior should change accordingly to match this new limitation regime: they should seek out nutrients that are deficient in the new diet. We investigated the relationship between diet and responses to nutrients using adult Costa Rican butterflies with contrasting feeding habits, testing the hypothesis that animals will respond more positively to nutrients that are scarcer in their diets. Via literature searches and our own data, we showed that nitrogen and sodium are both at lower concentration in nectar than in fruit. We therefore assessed butterflies' acceptance of sodium and four nitrogenous compounds that ranged in complexity from inorganic nitrogen (ammonium chloride) to protein (albumin). We captured wild butterflies, offered them aqueous solutions of each substance, and recorded whether they accepted (drank) or rejected each substance. Support for our hypothesis was mixed. Across the sexes, frugivores were four times more likely to accept amino acids (hydrolyzed casein) than nectivores, in opposition to expectation. In males, nectivores accepted sodium almost three times more frequently than frugivores, supporting expectations. Together, these results suggest that in butterflies, becoming frugivorous is associated with an increased receptivity to amino acids and decreased receptivity to sodium. Nectivory and frugivory are widespread feeding strategies in organisms as diverse as insects, birds, and bats; our results suggest that these feeding strategies may put different pressures on how animals fulfill their nutritional requirements. PMID:26267402

  13. Nutrient tasting and signaling mechanisms in the gut V. Mechanisms of immunologic sensation of intestinal contents.

    Shanahan, F

    2012-02-03

    Immune perception of intestinal contents reflects a functional dualism with systemic hyporesponsiveness to dietary antigens and resident microflora (oral tolerance) and active immune responses to mucosal pathogens. This facilitates optimal absorption of dietary nutrients while conserving immunologic resources for episodic pathogenic challenge. Discrimination between dangerous and harmless antigens within the enteric lumen requires continual sampling of the microenvironment by multiple potential pathways, innate and adaptive recognition mechanisms, bidirectional lymphoepithelial signaling, and rigorous control of effector responses. Errors in these processes disrupt mucosal homeostasis and are associated with food hypersensitivity and mucosal inflammation. Mechanisms of mucosal immune perception and handling of dietary proteins and other antigens have several practical and theoretical implications including vaccine design, therapy of systemic autoimmunity, and alteration of enteric flora with probiotics.

  14. Ecosystem adaptation to scarce nutrient resources: Do forest ecosystems shift from acquisition to recycling of phosphorus?

    Lang, F.; Kaupenjohann, M.

    2011-12-01

    Friederike Lang(1, Nicole Wellbrock(2, Martin Kaupenjohann(1 (1) Department of Soil Science, TU Berlin, 10587 Berlin, Germany; (2) vTI Eberswalde Agricultural food production is essential to our existence, yet we are using up the Earths stocks of phosphorus (P) for the fertilizer production (Cordell, 2009). Forest ecosystems that developed on marginal soil have developed highly efficient strategies for the uptake, usage and recycling of P, which might inspire solutions for the problem of P scarcity in agriculture. However, these efficient forest strategies are hardly investigated yet. Current literature concepts on the adaptation to low soil-P supply are mainly refined to individual organisms (e.g. the concept of uptake efficiency, Sattelmacher et al., 1994, and utilisation efficiency of plants, Compton and Cole, 1998). At the ecosystem level, however, low mineral-P supply requires an evolution of the system towards closed biogeochemical cycling (the concept of cycling efficiency). At the ecosystem level nutrient efficiency becomes rather a matter of transfer and distribution of resources among species, generations and soil components than of the capability of single organisms to acquire P sources. We plead for introducing the term ecosystem nutrition to cover this topic. Our general hypothesis is that P depletion of soils drives the development of forest ecosystems from geochemical P acquiring systems (mobilisation of P from the mineral phase) to biogeochemical P recycling systems (recycling of P from soil organic matter). We conclude that fundamental knowledge in the area of ecosystem nutrition is essential for forestry to mitigate the consequences of increasing N deposition, climate change and intensification of forest usage, which most likely interfere with essential nutrition strategies of forest ecosystems. Transfer of the knowledge on nutrition strategies and resource management of near-natural ecosystems to/in agricultural systems may finally contribute to

  15. Biochars Derived from Gasified Feedstocks Increase the Growth and Improve Nutrient Acquisition of Triticum aestivum (L. Grown in Agricultural Alfisols

    Kristin M. Trippe

    2015-08-01

    Full Text Available Biochars are produced by low-oxygen gasification or pyrolysis of organic waste products, and can be co-produced with energy, achieving waste diversion and delivering a soil amendment that can improve agricultural yields. Although many studies have reported the agronomic benefits of biochars produced from pyrolysis, few have interrogated the ability of gasified biochars to improve crop productivity. An earlier study described the ability of a biochar that was derived from gasified Kentucky bluegrass (KB seed screenings to impact the chemistry of acidic agricultural soils. However, that study did not measure the effects of the biochar amendment on plant growth or on nutrient acquisition. To quantify these effects we conducted a greenhouse study that evaluated wheat grown in agricultural soils amended with either the KB-based biochar or a biochar derived from a blend of woody mixed-waste. Our studies indicated that biochar amended soils promoted the growth of wheat in these agricultural alfisols. Our elemental analysis indicated that an attenuation of metal toxicity was likely responsible for the increased plant growth. The results of our study are placed in the context of our previous studies that characterized KB-sourced biochar and its effects on soil chemistry.

  16. Effects and Mechanisms of P and K Nutrients on Yield and Protein Content of Fodder Rice

    TANG Xiang-ru; YU Tie-qiao

    2002-01-01

    Effects and mechanisms of P and K nutrients on yield and protein content of Weiyou 56, a fodder hybrid rice combination, were studied through pot experiment and biochemical analysis. The results showed that the increase of P and K nutrients enhanced the activities of PEP carboxylase (PEPC), glutamine synthase (GS) and sucrose phosphate synthase (SPS) in leaves, sucrose synthase (SS), ADP glucose pyrophosphorylase (ADPGP) and GS in grains, and the chlorophyll content in leaves, soluble sugar and starch content in grains,protein N and total N content in leaves and grains. Howerer, they decreased soluble sugar content in leaves and led to an increase of protein content in brown rice, biomass, grain yield and harvest index. Excessive P nutrients slightly reduced SPS and ADPG activity in leaves and grains respectively.

  17. Rhizosphere in space and time – challenges for designing the most relevant root traits for efficient nutrient acquisition

    Hinsinger, Philippe

    2013-01-01

    [début du texte]The rhizosphere, i.e. the soil volume that is influenced by the activities of living roots, has been largelydocumented for its pivotal role in plant nutrition, and thus ecological significance in terrestrial ecosystems (e.g.Hinsinger et al., 2009). The number of studies on the fate of nutrients in the rhizosphere, especiallyphosphorus amongst major nutrients, iron and zinc amongst micronutrients, has considerably increased overthe past decades, as revealed by the published lit...

  18. MDAS2: A Data Acquisition System for the Soil Mechanic Laboratory

    The Soil Mechanic Laboratory in CIEMAT is working to characterize a bentonite which may be use in the storage of radioactive waste. The bentonite is studied with several tests, frequently used in soil mechanics. This document describes the data acquisition system used in one of these experiments

  19. Multiple symbiont acquisition strategies as an adaptive mechanism in the coral Stylophora pistillata.

    Kristen A Byler

    Full Text Available In obligate symbioses, the host's survival relies on the successful acquisition and maintenance of symbionts. Symbionts can either be transferred from parent to offspring via direct inheritance (vertical transmission or acquired anew each generation from the environment (horizontal transmission. With vertical symbiont transmission, progeny benefit by not having to search for their obligate symbionts, and, with symbiont inheritance, a mechanism exists for perpetuating advantageous symbionts. But, if the progeny encounter an environment that differs from that of their parent, they may be disadvantaged if the inherited symbionts prove suboptimal. Conversely, while in horizontal symbiont acquisition host survival hinges on an unpredictable symbiont source, an individual host may acquire genetically diverse symbionts well suited to any given environment. In horizontal acquisition, however, a potentially advantageous symbiont will not be transmitted to subsequent generations. Adaptation in obligate symbioses may require mechanisms for both novel symbiont acquisition and symbiont inheritance. Using denaturing-gradient gel electrophoresis and real-time PCR, we identified the dinoflagellate symbionts (genus Symbiodinium hosted by the Red Sea coral Stylophora pistillata throughout its ontogenesis and over depth. We present evidence that S. pistillata juvenile colonies may utilize both vertical and horizontal symbiont acquisition strategies. By releasing progeny with maternally derived symbionts, that are also capable of subsequent horizontal symbiont acquisition, coral colonies may acquire physiologically advantageous novel symbionts that are then perpetuated via vertical transmission to subsequent generations. With symbiont inheritance, natural selection can act upon the symbiotic variability, providing a mechanism for coral adaptation.

  20. Carbon Acquisition by Cyanobacteria: Mechanisms, Comparative Genomics, and Evolution

    Kaplan, Aaron; Hagemann, Martin; Bauwe, Hermann; Kahlon, Shira; Ogawa, Teruo

    2008-01-01

    In this chapter we mainly focus on the mechanisms of inorganic carbon uptake, photorespiration, and the regulation between the metabolic fluxes involved in photoautotrophic, photomixotrophic and heterotrophic growth. We identify the genes involved, their regulation and phylogeny. Living in an environment where the CO₂ concentration is considerably lower than required to saturate their carboxylating enzyme, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), cyanobacteria acquired the CO₂ concentrating mechanism (CCM) that enables them to accumulate CO₂ at the carboxylation site. All the cyanobacteria examined to date are able to fix CO₂ into carbohydrates. However, in addition to variance in the range of physical growth conditions, cyanobacteria also vary substantially in their ability to consume organic carbon from their surroundings. Many strains are obligate photoautotrophs where the sole carbon source is CO₂, while others are able to perform photomixotrophic or even heterotrophic growth using a wide variety of organic substances (c.f. Rippka et al., 1979; Stal and Moezelaar, 1997b). Cyanobacteria constitute a unique case where the anabolic and catabolic carbohydrate metabolisms function in the same cellular compartment. In addition, the photosynthetic and respiratory electron transport pathways share components in the thylakoid membranes. Despite its importance to our understanding of cyanobacterial metabolism, little is known about the mechanisms involved in the shifts between photoautotrophic, heterotrophic and photomixotrophic modes of growth, and their regulation; between the different pathways of carbohydrate breakdown- glycolysis, fermentation, the oxidative pentose phosphate, the Krebs cycle and the photorespiratory pathways. In this chapter we shall briefly focus on recent advances in our understanding of the CCM and carbon metabolism in cyanobacteria.

  1. Carbon acquisition by Cyanobacteria: Mechanisms, Comparative Genomics and Evolution

    Kaplan, Aaron; Hagemann, Martin; Bauwe, Hermann; Kahlon, Shira; Ogawa, Teruo

    2008-01-01

    In this chapter we mainly focus on the mechanisms of inorganic carbon uptake, photorespiration, and the regulation between the metabolic fluxes involved in photoautotrophic, photomixotrophic and heterotrophic growth. We identify the genes involved, their regulation and phylogeny. Living in an environment where the CO₂ concentration is considerably lower than required to saturate their carboxylating enzyme, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), cyanobacteria acquired the CO₂ concentrating mechanism (CCM) that enables them to accumulate CO₂ at the carboxylation site. All the cyanobacteria examined to date are able to fix CO₂ into carbohydrates. However, in addition to variance in the range of physical growth conditions, cyanobacteria also vary substantially in their ability to consume organic carbon from their surroundings. Many strains are obligate photoautotrophs where the sole carbon source is CO₂, while others are able to perform photomixotrophic or even heterotrophic growth using a wide variety of organic substances (c.f. Rippka et al., 1979; Stal and Moezelaar, 1997b). Cyanobacteria constitute a unique case where the anabolic and catabolic carbohydrate metabolisms function in the same cellular compartment. In addition, the photosynthetic and respiratory electron transport pathways share components in the thylakoid membranes. Despite its importance to our understanding of cyanobacterial metabolism, little is known about the mechanisms involved in the shifts between photoautotrophic, heterotrophic and photomixotrophic modes of growth, and their regulation; between the different pathways of carbohydrate breakdown- glycolysis, fermentation, the oxidative pentose phosphate, the Krebs cycle and the photorespiratory pathways. In this chapter we shall briefly focus on recent advances in our understanding of the CCM and carbon metabolism in cyanobacteria.

  2. α8β1 integrin regulates nutrient absorption through an Mfge8-PTEN dependent mechanism

    Khalifeh-Soltani, Amin; Ha, Arnold; Podolsky, Michael J; McCarthy, Donald A; McKleroy, William; Azary, Saeedeh; Sakuma, Stephen; Tharp, Kevin M; Wu, Nanyan; Yokosaki, Yasuyuki; Hart, Daniel; Stahl, Andreas; Atabai, Kamran

    2016-01-01

    Coordinated gastrointestinal smooth muscle contraction is critical for proper nutrient absorption and is altered in a number of medical disorders. In this work, we demonstrate a critical role for the RGD-binding integrin α8β1 in promoting nutrient absorption through regulation of gastrointestinal motility. Smooth muscle-specific deletion and antibody blockade of α8 in mice result in enhanced gastric antral smooth muscle contraction, more rapid gastric emptying, and more rapid transit of food through the small intestine leading to malabsorption of dietary fats and carbohydrates as well as protection from weight gain in a diet-induced model of obesity. Mechanistically, ligation of α8β1 by the milk protein Mfge8 reduces antral smooth muscle contractile force by preventing RhoA activation through a PTEN-dependent mechanism. Collectively, our results identify a role for α8β1 in regulating gastrointestinal motility and identify α8 as a potential target for disorders characterized by hypo- or hyper-motility. DOI: http://dx.doi.org/10.7554/eLife.13063.001 PMID:27092791

  3. Preparation and nutrient release mechanism of a polymer as slow-release compound fertilizer

    A new kind of polymer as slow-release fertilizer containing nitrogen, phosphorus and potassium (PSRNPK) was synthesized and the structure of the fertilizer was characterized by the FTIR spectrum. The N, P and K contents of the fertilizer are 21.4 wt%, 10.0 wt% (shown by P/sub 2/O/sub 5/), and 6.5 wt% (shown by K/sub 2/O), respectively. Because the nutrient release of polymer as slow-release fertilizer depended on the speed of degradation, this study evaluated the release patterns of N, P, and K from PSRNPK at pH values of 4.0, 5.6, 7.0, 8.4, and 10.0. Additionally, the effect of temperature on the nutrients release behaviors was investigated. The results showed that the PSRNPK possessed an excellent slow release property, and the releases of N, P are pH dependent. N was released rapidly in both acid and base systems, respectively, while the release of P was suppressed by acid, and the K release speed was not influenced by the pH. Hydrolysis reaction mechanism was proposed based on the controlled experiments. (author)

  4. Net root growth and nutrient acquisition in response to predicted climate change in two contrasting heathland species

    Arndal, M.F.; Merrild, M.P.; Michelsen, A.;

    2013-01-01

    colonization, and fine root N and P uptake by root assay of Deschampsia flexuosa and Calluna vulgaris.Net root growth increased under elevated CO2, warming and drought, with additive effects among the factors. Arbuscular mycorrhizal colonization increased in response to elevated CO2, while ericoid mycorrhizal...... colonization was unchanged. The uptake of N and P was not increased proportionally with root growth after 5 years of treatment.While aboveground biomass was unchanged, the root growth was increased under elevated CO2. The results suggest that plant production may be limited by N (but not P) when exposed...... to elevated CO2. The species-specific response to the treatments suggests different sensitivity to global change factors, which could result in changed plant competitive interactions and belowground nutrient pool sizes in response to future climate change....

  5. Mechanisms underlying nutrient-induced segmentation in isolated guinea pig small intestine.

    Gwynne, R M; Bornstein, J C

    2007-04-01

    Mechanisms underlying nutrient-induced segmentation within the gut are not well understood. We have shown that decanoic acid and some amino acids induce neurally dependent segmentation in guinea pig small intestine in vitro. This study examined the neural mechanisms underlying segmentation in the circular muscle and whether the timing of segmentation contractions also depends on slow waves. Decanoic acid (1 mM) was infused into the lumen of guinea pig duodenum and jejunum. Video imaging was used to monitor intestinal diameter as a function of both longitudinal position and time. Circular muscle electrical activity was recorded by using suction electrodes. Recordings from sites of segmenting contractions showed they are always associated with excitatory junction potentials leading to action potentials. Recordings from sites oral and anal to segmenting contractions revealed inhibitory junction potentials that were time locked to those contractions. Slow waves were never observed underlying segmenting contractions. In paralyzed preparations, intracellular recording revealed that slow-wave frequency was highly consistent at 19.5 (SD 1.4) cycles per minute (c/min) in duodenum and 16.6 (SD 1.1) c/min in jejunum. By contrast, the frequencies of segmenting contractions varied widely (duodenum: 3.6-28.8 c/min, median 10.8 c/min; jejunum: 3.0-27.0 c/min, median 7.8 c/min) and sometimes exceeded slow-wave frequencies for that region. Thus nutrient-induced segmentation contractions in guinea pig small intestine do not depend on slow-wave activity. Rather they result from a neural circuit producing rhythmic localized activity in excitatory motor neurons, while simultaneously activating surrounding inhibitory motor neurons. PMID:17218474

  6. Standard guide for evaluating data acquisition systems used in cyclic fatigue and fracture mechanics testing

    American Society for Testing and Materials. Philadelphia

    1998-01-01

    1.1 This guide covers how to understand and minimize the errors associated with data acquisition in fatigue and fracture mechanics testing equipment. This guide is not intended to be used instead of certified traceable calibration or verification of data acquisition systems when such certification is required. It does not cover static load verification, for which the user is referred to the current revision of Practices E 4, or static extensometer verification, for which the user is referred to the current revision of Practice E 83. The user is also referred to Practice E 467. 1.2 The output of the fatigue and fracture mechanics data acquisition systems described in this guide is essentially a stream of digital data. Such digital data may be considered to be divided into two types- Basic Data, which are a sequence of digital samples of an equivalent analog waveform representing the output of transducers connected to the specimen under test, and Derived Data, which are digital values obtained from the Basic D...

  7. Phytotoxic Mechanism of Nanoparticles: Destruction of Chloroplasts and Vascular Bundles and Alteration of Nutrient Absorption.

    Nhan, Le Van; Ma, Chuanxin; Rui, Yukui; Liu, Shutong; Li, Xuguang; Xing, Baoshan; Liu, Liming

    2015-01-01

    This study focused on determining the phytotoxic mechanism of CeO2 nanoparticles (NPs): destroying chloroplasts and vascular bundles and altering absorption of nutrients on conventional and Bt-transgenic cottons. Experiments were designed with three concentrations of CeO2 NPs including: 0, 100 and 500 mg·L(-1), and each treatment was three replications. Results indicate that absorbed CeO2 nanoparticles significantly reduced the Zn, Mg, Fe, and P levels in xylem sap compared with the control group and decreased indole-3-acetic acid (IAA) and abscisic acid (ABA) concentrations in the roots of conventional cotton. Transmission electron microscopy (TEM) images revealed that CeO2 NPs were absorbed into the roots and subsequently transported to the stems and leaves of both conventional and Bt-transgenic cotton plants via xylem sap. In addition, the majority of aggregated CeO2 NPs were attached to the external surface of chloroplasts, which were swollen and ruptured, especially in Bt-transgenic cotton. The vascular bundles were destroyed by CeO2 nanoparticles, and more damage was observed in transgenic cotton than conventional cotton. PMID:26108166

  8. EXTERNAL CORPORATE GOVERNANCE MECHANISMS: MERGERS AND ACQUISITIONS ON THE BRAZILIAN MARKET

    Mario Augusto Parente Monteiro

    2014-08-01

    Full Text Available The research aims to answer the following question: What is the effectiveness of mergers and acquisitions in the Brazilian market as external corporate governance mechanism? The main objective of the study is to verify if mergers and acquisitions operations in Brazilian market may act as an external mechanism of corporate governance, replacing managers and, as a consequence of changes in management, improving financial performance. The study is exploratory, qualitative in its approach, supported by documentary research on secondary data concerning an intentional sample of Brazilian companies aiming to identify the effect of M&A operations on the corporate governance structure of the acquired firm and on its financial results. Data obtained on the website of the Brazilian Securities and Exchange Commission (CVM, related to Brazilian M&A operations in the period 2005-2010, were analyzed. Although M&A operations in Brazil were found to have disciplinary nature in our sample of firms in the studied period, our results are inconclusive regarding the effectiveness of these transactions and external governance mechanisms.

  9. Epigenetic mechanisms of nutrient-induced modulation of gene expression and cellular functions

    Utilizing next-generation sequencing technology in combination with chromatin immunoprecipitation (ChIP) technology, our study provides systematic and novel insights into the relationships between nutrition and epigenetics. One paradigmatic example of nutrient-epigenetic-phenotype relationship is th...

  10. [Research advances on controlled-release mechanisms of nutrients in coated fertilizers].

    Zhang, Haijun; Wu, Zhijie; Liang, Wenju; Xie, Hongtu

    2003-12-01

    Using encapsulation techniques to coat easily soluble fertilizers is an important way to improve fertilizer use efficiency while reduce environmental hazards. Based on a wide range of literature collection on coated fertilizer research, the theories, processes, and characters of nutrient controlled-release from coated fertilizer were discussed, and the factors affecting nutrient controlled-release and the mathematical simulations on it were reviewed. The main tendencies related to this research in China were also put forward. PMID:15031946

  11. Plant senescence: A mechanism for nutrient release in temperate agricultural wetlands

    The beneficial uptake of nutrients by wetland plants is countered to some extent by nutrient release back into the aquatic environment due to vegetative die-back. This current study examined whether Leersia oryzoides, a common wetland plant, exhibits luxury uptake of nutrients from simulated farm runoff. The study also tested whether with subsequent decomposition, these nutrients are released back into the water column. When exposed to elevated (>2 mg/L N and P) runoff, L. oryzoides assimilated significantly higher concentrations of nitrogen (p < 0.001) and phosphorus (p < 0.001) in above-ground biomass as compared to non-enriched treatments (<0.05 mg/L N and P). Subsequently, senescence of enriched above-ground biomass yielded significantly higher concentrations of phosphorus (2.19 ± 0.84 mg P/L). Using L. oryzoides as our model, this study demonstrates nitrogen and phosphorus sequestration during the growing season and release of phosphorus in the winter. - Release of sequestered nutrients during plant senescence

  12. Agronomic evaluation of a fertiliser with D-CODER technology, a new mechanism for the slow release of nutrients

    Arrobas, Margarida; Rodrigues, M. A.

    2013-01-01

    D-CODER is a fertilizer with a new slow-release mechanism consisting of an organomineral matrix that releases the nutrients only in the presence of growing plants. Pot and field experiments were carried out to study the release pattern of N from D-CODER. The experiments included grown and bare soil plots. The fertilizer treatments were DCODER, ammonium nitrate (ANpreplant), and the control. A fourth treatment was added to the cultivated plots, consisting of splitting the ammoni...

  13. Responses of soil nutrient to driving mechanism in Taihu Lake basin in last 20 years

    2001-01-01

    The objectives of this study is to understand the changing law of soil nutrient quality in Taihu Lake basin, Yangtze Delta in last 20 years, and reveal the relationship between soil nutrient changes and human driving forces in regional level over long period of time. Experiment on long-term collecting samples was conducted to study changes of soil organic matter, total N, available N, available P and available K in Dongting town, Wuxi city during the last 20 years. The paper analyses the co-relationship of the fluctuation of soil nutrient and state policy, cultivating practice, agricultural input, and per hectare agricultural net income. The results showed that at first the content of soil organic matter increased, then decreased, and increased again. The content of total N and available N steadily increased. The content of available K and available P steadily decreased. The authors found that the influence of state policy and cultivating practice on soil nutrient quality index (SNQI) is obvious, agricultural input and SNQI are positively correlated, and per hectare agricultural net income and SNQI are negatively correlated.

  14. Proximal gastric response to small intestinal nutrients is abnormal in mechanically ventilated critically iii patients

    Nam Q Nguyen; Robert J Fraser; Marianne Chapman; Laura K Bryant; Richard H Holloway; Rosalie Vozzo; Christine Feinle-Bisset

    2006-01-01

    AIM: To determine the response of the proximal stomach to small intestinal nutrients in critically iii patients.METHODS: Proximal gastric motility was measured in 13 critically iii patients (49.3 ± 4.7 years) and 12 healthy volunteers (27.7 ± 2.9 years) using a barostat technique.Recordings were performed at baseline, during a 60-min intra-duodenal infusion of Ensure(R) (2 kcal/min), and for 2 h following the infusion. Minimum distending pressure (MDP), intra-bag volume and fundic wave activity were determined.RESULTS: The MDP was higher in patients (11.7 ± 1.1 vs 7.8 ± 0.7 mmHg; P < 0.01). Baseline intrabag volumes were similar in the 2 groups. In healthy subjects, a 'bimodal' proximal gastric volume response was observed. In patients, the initial increase in proximal gastric volume was small and delayed, but eventually reached a maximal volume similar to that of healthy subjects. In healthy subjects, the proximal gastric volume rapidly returned to baseline level after nutrient infusion (median 18 min). In contrast, the recovery of volume to baseline was delayed in critically ill patients (median 106 min). In 6 patients, the volume had not returned to baseline level 2 hours after nutrient infusion.In patients, fundic volume waves were less frequent (P < 0.05) and had lower amplitude (P < 0.001), compared to healthy subjects.CONCLUSION: In critical illness, proximal gastric motor responses to small intestinal nutrient stimulation are abnormal.

  15. Seasonal and interannual variability of physical and biological dynamics at the shelfbreak front of the Middle Atlantic Bight: nutrient supply mechanisms

    R. He

    2011-10-01

    Full Text Available A high-resolution, 3-dimensional coupled biophysical model is used to simulate ocean circulation and ecosystem variations at the shelfbreak front of the Middle Atlantic Bight (MAB. Favorable comparisons between satellite observations and model hindcast solutions from January 2004 to November 2007 indicate the model has intrinsic skills in resolving fundamental physical and biological dynamics at the MAB shelfbreak. Seasonal and interannual variability of ocean physical and biological states and their driving mechanisms are further analyzed. The domain-wide upper water column nutrient content is found to peak in late winter-early spring. Phytoplankton spring bloom starts 1–2 months later, followed by zooplankton bloom in early summer. Our analysis shows the variability of shelfbreak nutrient supply is controlled by local mixing that deepens the mixed layer and injects deep ocean nutrients into the upper water column and alongshore nutrient transport by the shelfbreak jet and associated currents. Nutrient vertical advection associated with the shelfbreak bottom boundary layer convergence is another significant contributor. Spring mean nutrient budget diagnostics along the Nantucket transect are compared between nutrient rich 2004 and nutrient poor 2007. Physical advection and diffusion play the major role in determining strong interannual variations in shelfbreak nutrient content. The biological (source minus sink term is very similar between these two years.

  16. On the Acquisition of Some Basic Word Spelling Mechanisms in a Deep (French) and a Shallow (Spanish) System

    Carrillo, Maria Soledad; Alegria, Jesus; Marin, Javier

    2013-01-01

    An experiment was carried out to compare the time course of the acquisition of two basic spelling mechanisms in Spanish, a shallow system, and French, a deep system. The first was lexical. It relies on the orthographic lexicon, a hypothetical structure containing the orthographic representations of words accessible for word spelling. To evaluate…

  17. Perinatal acquisition of drug-resistant HIV-1 infection: mechanisms and long-term outcome

    Dollfus Catherine

    2009-09-01

    Full Text Available Abstract Background Primary-HIV-1-infection in newborns that occurs under antiretroviral prophylaxis that is a high risk of drug-resistance acquisition. We examine the frequency and the mechanisms of resistance acquisition at the time of infection in newborns. Patients and Methods We studied HIV-1-infected infants born between 01 January 1997 and 31 December 2004 and enrolled in the ANRS-EPF cohort. HIV-1-RNA and HIV-1-DNA samples obtained perinatally from the newborn and mother were subjected to population-based and clonal analyses of drug resistance. If positive, serial samples were obtained from the child for resistance testing. Results Ninety-two HIV-1-infected infants were born during the study period. Samples were obtained from 32 mother-child pairs and from another 28 newborns. Drug resistance was detected in 12 newborns (20%: drug resistance to nucleoside reverse transcriptase inhibitors was seen in 10 cases, non-nucleoside reverse transcriptase inhibitors in two cases, and protease inhibitors in one case. For 9 children, the detection of the same resistance mutations in mothers' samples (6 among 10 available and in newborn lymphocytes (6/8 suggests that the newborn was initially infected by a drug-resistant strain. Resistance variants were either transmitted from mother-to-child or selected during subsequent temporal exposure under suboptimal perinatal prophylaxis. Follow-up studies of the infants showed that the resistance pattern remained stable over time, regardless of antiretroviral therapy, suggesting the early cellular archiving of resistant viruses. The absence of resistance in the mother of the other three children (3/10 and neonatal lymphocytes (2/8 suggests that the newborns were infected by a wild-type strain without long-term persistence of resistance when suboptimal prophylaxis was stopped. Conclusion This study confirms the importance of early resistance genotyping of HIV-1-infected newborns. In most cases (75%, drug

  18. Defining planktonic protist functional groups on mechanisms for energy and nutrient acquisition; incorporation of diverse mixotrophic strategies

    Mitra, Aditee; Flynn, Kevin J; Tillmann, Urban; Raven, John A; Caron, David; Stoecker, Diane K; Hansen, Per Juel; Hallegraeff, Gustaff; Sanders, Robert W; Wilken, Susanne; Mcmanus, George; Johnson, Matthew; Pitta, Paraskevi; Våge, Selina; Berge, Terje; Calbet, Albert; Thingstad, Frede; Jeong, Hae Jin; Burkholder, JoAnn; Glibert, Patricia M; Granéli, Edna; Lundgren, Veronica

    2016-01-01

    Arranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic “phytoplankton” and phagotrophic “mi...

  19. Epigenetic mechanisms at work: Exploiting nutrient-specific modulation of genetic networks

    “Epigenetics” was used to describe actions of genes with their environment that bring the phenotype into being”. The modern version of epigenetics includes the molecular mechanisms that influence the phenotypic outcome of a gene or genome, in absence of changes to the underlying DNA sequence. A hos...

  20. The dilemmas of the gourmet fly: The molecular and neuronal mechanism of feeding and nutrient decision making in Drosophila

    Pavel M Itskov

    2013-02-01

    Full Text Available To survive and successfully reproduce animals need to maintain a balanced intake of nutrients and energy. The nervous system of insects has evolved multiple mechanisms to regulate feeding behaviour. When animals are faced with the choice to feed, several decisions must be made: whether or not to eat, how much to eat, what to eat and when to eat. Using Drosophila melanogaster substantial progress has been achieved in understanding the neuronal and molecular mechanisms controlling feeding decisions. These feeding decisions are implemented in the nervous system on multiple levels, from alterations in the sensitivity of peripheral sensory organs to the modulation of memory systems. This review discusses methodologies developed in order to study insect feeding, the effects of neuropeptides and neuromodulators on feeding behaviour, behavioural evidence supporting the existence of internal energy sensors, neuronal and molecular mechanisms controlling protein intake and finally the regulation of feeding by circadian rhythms and sleep. From the discussed data a conceptual framework starts to emerge which aims to explain the molecular and neuronal processes maintaining the stability of the internal milieu.

  1. Pea–barley intercropping for efficient symbiotic N2-fixation, soil N acquisition and use of other nutrients in European organic cropping systems

    Hauggaard-Nielsen, Henrik; Gooding, M.; Ambus, Per; Corre-Hellou, Guenaelle; Dahlmann, C.; Dibet, A.; Fragstein, P. von; Pristeri, A.; Monti, M.; Jensen, Erik Steen

    2009-01-01

    Complementarity in acquisition of nitrogen (N) from soil and N2-fixation within pea and barley intercrops was studied in organic field experiments across Western Europe (Denmark, United Kingdom, France, Germany and Italy). Spring pea and barley were sown either as sole crops, at the recommended...... plant density (P100 and B100, respectively) or in replacement (P50B50) or additive (P100B50) intercropping designs, in each of three cropping seasons (2003–2005). Irrespective of site and intercrop design, Land Equivalent Ratios (LER) between 1.4 at flowering and 1.3 at maturity showed that total N...... recovery was greater in the pea–barley intercrops than in the sole crops suggesting a high degree of complementarity over a wide range of growing conditions. Complementarity was partly attributed to greater soil mineral N acquisition by barley, forcing pea to rely more on N2-fixation. At all sites the...

  2. Pea-barley intercropping for efficient symbiotic N-2-fixation, soil N acquisition and use of other nutrients in European organic cropping systems

    Hauggaard-Nielsen, Henrik; Gooding, M.; Ambus, Per;

    2009-01-01

    recovery was greater in the pea-barley intercrops than in the sole Crops Suggesting a high degree of complementarity over a wide range of growing conditions. Complementarity was partly attributed to greater soil mineral N acquisition by barley, forcing pea to rely more on N-2-fixation. At all sites the...... highly resilient. It is concluded that pea-barley intercropping is a relevant cropping strategy to adopt when trying to optimize N-2-fixation inputs to the cropping system....

  3. Transcriptome analysis of intraspecific competition in Arabidopsis thaliana reveals organ-specific signatures related to nutrient acquisition and general stress response pathways

    Masclaux Frédéric G

    2012-11-01

    Full Text Available Abstract Background Plants are sessile and therefore have to perceive and adjust to changes in their environment. The presence of neighbours leads to a competitive situation where resources and space will be limited. Complex adaptive responses to such situation are poorly understood at the molecular level. Results Using microarrays, we analysed whole-genome expression changes in Arabidopsis thaliana plants subjected to intraspecific competition. The leaf and root transcriptome was strongly altered by competition. Differentially expressed genes were enriched in genes involved in nutrient deficiency (mainly N, P, K, perception of light quality, and responses to abiotic and biotic stresses. Interestingly, performance of the generalist insect Spodoptera littoralis on densely grown plants was significantly reduced, suggesting that plants under competition display enhanced resistance to herbivory. Conclusions This study provides a comprehensive list of genes whose expression is affected by intraspecific competition in Arabidopsis. The outcome is a unique response that involves genes related to light, nutrient deficiency, abiotic stress, and defence responses.

  4. Calcification generates protons for nutrient and bicarbonate uptake

    McConnaughey, T. A.; Whelan, J. F.

    1997-03-01

    The biosphere's great carbonate deposits, from caliche soils to deep-sea carbonate oozes, precipitate largely as by-products of autotrophic nutrient acquisition physiologies. Protons constitute the critical link: Calcification generates protons, which plants and photosynthetic symbioses use to assimilate bicarbonate and nutrients. A calcium ATPase-based "trans" mechanism underlies most biological calcification. This permits high calcium carbonate supersaturations and rapid carbonate precipitation. The competitive advantages of calcification become especially apparent in light and nutrient-deficient alkaline environments. Calcareous plants often dominate the lower euphotic zone in both the benthos and the plankton. Geographically and seasonally, massive calcification concentrates in nutrient-deficient environments including alkaline soils, coral reefs, cyanobacterial mats and coccolithophorid blooms. Structural and defensive uses for calcareous skeletons are sometimes overrated.

  5. Short-term effect of soil disturbance by mechanical weeding on plant available nutrients in an organic vs conventional rotations experiment

    Owen, D.; Leblanc, S.; Fillmore, S A E

    2006-01-01

    The question whether soil disturbance from mechanical weeding in organic systems affects nutrient release from organic matter in compost-amended soil was examined in a long-term organic-versus-conventional rotational cropping system experiment over three years. The experimental design included continuous snap beans, and a fully phased snap beans/fall rye crop rotation sequence. Treatments were combinations of yearly applied fertiliser (synthetic fertiliser, 1× compost, 3× compost) and weed co...

  6. Evolution of photorespiration from cyanobacteria to land plants, considering protein phylogenies and acquisition of carbon concentrating mechanisms.

    Hagemann, Martin; Kern, Ramona; Maurino, Veronica G; Hanson, David T; Weber, Andreas P M; Sage, Rowan F; Bauwe, Hermann

    2016-05-01

    Photorespiration and oxygenic photosynthesis are intimately linked processes. It has been shown that under the present day atmospheric conditions cyanobacteria and all eukaryotic phototrophs need functional photorespiration to grow autotrophically. The question arises as to when this essential partnership evolved, i.e. can we assume a coevolution of both processes from the beginning or did photorespiration evolve later to compensate for the generation of 2-phosphoglycolate (2PG) due to Rubisco's oxygenase reaction? This question is mainly discussed here using phylogenetic analysis of proteins involved in the 2PG metabolism and the acquisition of different carbon concentrating mechanisms (CCMs). The phylogenies revealed that the enzymes involved in the photorespiration of vascular plants have diverse origins, with some proteins acquired from cyanobacteria as ancestors of the chloroplasts and others from heterotrophic bacteria as ancestors of mitochondria in the plant cell. Only phosphoglycolate phosphatase was found to originate from Archaea. Notably glaucophyte algae, the earliest branching lineage of Archaeplastida, contain more photorespiratory enzymes of cyanobacterial origin than other algal lineages or land plants indicating a larger initial contribution of cyanobacterial-derived proteins to eukaryotic photorespiration. The acquisition of CCMs is discussed as a proxy for assessing the timing of periods when photorespiratory activity may have been enhanced. The existence of CCMs also had marked influence on the structure and function of photorespiration. Here, we discuss evidence for an early and continuous coevolution of photorespiration, CCMs and photosynthesis starting from cyanobacteria via algae, to land plants. PMID:26931168

  7. The Acquisition of Past Tense in English/Norwegian Bilingual Children Single versus Dual Mechanisms

    Maja Jensvoll

    2004-01-01

    Full Text Available In a study of three Norwegian/English bilingual siblings, their strategies for acquiring past tense of verbs in both languages were examined. Elicitation tests were performed in both languages and the children’s performance and error patterns were examined. These results were then compared to data from monolingual English and Norwegian speaking children. The results are discussed within the framework of the Single Mechanism Account Hypothesis, a Connectionist approach, and the Dual Mechanism Account Hypothesis, a Generative Approach. The current study suggests support for the Dual Mechanism Approach Hypothesis. It seems that the children in the current study did in fact create rules for past tense which they could apply by default.

  8. 基于LabVIEW的力学应变采集软件设计%design of mechanical strain acquisition

    吴忠锴; 马铁华; 梁志剑

    2012-01-01

    Text programming language are characterized by complex and long time of developing, combined with the needs of the mechanics of materials strain data acquisition, The data acquisition and control software was designed using LabVIEW2010o The USB communication interface between hardware and PC was realized by taking DLL. using queue and thread technology adjust the speed of data transmission , ensure that the data is not lost, aviod the program to paralyze because of long data acquisition , improve the reliability of program, it follow the modular design idea to facilitate future improvement and maintenance ,Experiments show that the system can complete real-time strain acquisition, processing, display, storage and data readback.The software have advantages of simple interface, short development cycle, stable performance and easy maintenance, achieve good result in teaching practice%针对文本编程语言复杂,开发周期长的特点,结合材料力学应变数据采集实验的需要,存LabVIEW2010平台下设计了数据采集控制软件。调用动态链接库DLL实现下位机与上位机USB通信,利用队列技术、多线程技术调节了数据传递速度、保证数据不丢失,避免由于长时间数据采集造成的程序瘫痪,提高了程序可靠性,遵循模块化的设计思想,方便以后改进和维护,实验表明可以完成对应变信号实时采集、处理显示、存储及数据回放的功能。软件接口简单、开发周期短、性能稳定、易于维护,用于教学实践中,取得较好效果。

  9. MDAS2: A Data Acquisition System for the Soil Mechanic Laboratory; Sistema MDAS2 para Toma de Datos en el Laboratorio de Mecanica de Suelos

    Alberdi, J.; Barcala, J. M. [Ciemat. Madrid (Spain)

    2000-07-01

    The soil Mechanic Laboratory in CIEMAT is working to characterize a bentonite which may be use in the storage of radioactive waste. The bentonite is studied with several tests, frequently used in soil mechanics. This document describes the data acquisition system used in one of these experiments.

  10. Factors influencing the technology upgrading and catch-up of Chinese wind turbine manufacturers: Technology acquisition mechanisms and government policies

    This paper uses firm level data for the Chinese wind turbine manufacturing industry from 1998 to 2009 to quantify the effects of technology acquisition mechanisms – purchasing production licenses from foreign manufacturers, joint design with foreign design firms, joint-ventures and domestic R and D – on wind turbine manufacturers' technology levels (as measured by turbine size, in megawatts). It also examines the impacts of government policies on manufacturer technology levels. Technology upgrading (measured by increase of turbine size) and catch-up (measured by decrease in the distance to the world technology frontier in terms of turbine size) are used to measure advances in technology level. Results from econometric modeling studies indicate that firms' technology acquisition mechanisms and degree of business diversification are statistically significant factors in influencing technology upgrading. Similar results were found for the catch-up variable (i.e., distance to the world technology frontier). The influence of government policies is significant for technology upgrading but not catch-up. These and other modeling results are shown to have implications for both policymakers and wind turbine manufacturers. - Highlights: ► Technology acquired through joint design has the highest level. ► Technology acquired through purchasing production license has the lowest level. ► Technology acquired through domestic R and D has the level in between. ► A firm with related other businesses tends to have a higher level of technology. ► The influence of policies is significant for technology upgrade but not catch-up

  11. The integrity of lexical acquisition mechanisms in autism spectrum disorders: A research review.

    Arunachalam, Sudha; Luyster, Rhiannon J

    2016-08-01

    Research on autism spectrum disorders (ASD) has rapidly expanded in recent years, yielding important developments in both theory and practice. While we have gained important insights into how children with ASD differ from typically developing (TD) children in terms of phenotypic features, less has been learned about if and how development in ASD differs from typical development in terms of underlying mechanisms of change. This article aims to provide a review of processes subserving lexical development in ASD, with the goal of identifying contributing factors to the heterogeneity of language outcomes in ASD. The focus is on available evidence of the integrity or disruption of these mechanisms in ASD, as well as their significance for vocabulary development; topics include early speech perception and preference, speech segmentation, word learning, and category formation. Significant gaps in the literature are identified and future directions are suggested. Autism Res 2016, 9: 810-828. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. PMID:26688218

  12. The molecular mechanism of Zinc acquisition by the neisserial outer-membrane transporter ZnuD

    Calmettes, Charles; Ing, Christopher; Buckwalter, Carolyn M.; El Bakkouri, Majida; Chieh-Lin Lai, Christine; Pogoutse, Anastassia; Gray-Owen, Scott D.; Pomès, Régis; Moraes, Trevor F.

    2015-08-01

    Invading bacteria from the Neisseriaceae, Acinetobacteriaceae, Bordetellaceae and Moraxellaceae families express the conserved outer-membrane zinc transporter zinc-uptake component D (ZnuD) to overcome nutritional restriction imposed by the host organism during infection. Here we demonstrate that ZnuD is required for efficient systemic infections by the causative agent of bacterial meningitis, Neisseria meningitidis, in a mouse model. We also combine X-ray crystallography and molecular dynamics simulations to gain insight into the mechanism of zinc recognition and transport across the bacterial outer-membrane by ZnuD. Because ZnuD is also considered a promising vaccine candidate against N. meningitidis, we use several ZnuD structural intermediates to map potential antigenic epitopes, and propose a mechanism by which ZnuD can maintain high sequence conservation yet avoid immune recognition by altering the conformation of surface-exposed loops.

  13. NPKS uptake, sensing, and signaling and miRNAs in plant nutrient stress.

    Nath, Manoj; Tuteja, Narendra

    2016-05-01

    Sessile nature of higher plants consequently makes it highly adaptable for nutrient absorption and acquisition from soil. Plants require 17 essential elements for their growth and development which include 14 minerals (macronutrients: N, P, K, Mg, Ca, S; micronutrients: Cl, Fe, B, Mn, Zn, Cu, Ni, Mo) and 3 non-mineral (C, H, O) elements. The roots of higher plants must acquire these macronutrients and micronutrients from rhizosphere and further allocate to other plant parts for completing their life cycle. Plants evolved an intricate series of signaling and sensing cascades to maintain nutrient homeostasis and to cope with nutrient stress/availability. The specific receptors for nutrients in root, root system architecture, and internal signaling pathways help to develop plasticity in response to the nutrient starvation. Nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) are essential for various metabolic processes, and their deficiency negatively effects the plant growth and yield. Genes coding for transporters and receptors for nutrients as well as some small non-coding RNAs have been implicated in nutrient uptake and signaling. This review summarizes the N, P, K, and S uptake, sensing and signaling events in nutrient stress condition especially in model plant Arabidopsis thaliana and involvement of microRNAs in nutrient deficiency. This article also provides a framework of uptake, sensing, signaling and to highlight the microRNA as an emerging major players in nutrient stress condition. Nutrient-plant-miRNA cross talk may help plant to cope up nutrient stress, and understanding their precise mechanism(s) will be necessary to develop high yielding smart crop with low nutrient input. PMID:26085375

  14. Mechanical Alteration And Contamination Issues In Automated Subsurface Sample Acquisition And Handling

    Glass, B. J.; Cannon, H.; Bonaccorsi, R.; Zacny, K.

    2006-12-01

    The Drilling Automation for Mars Exploration (DAME) project's purpose is to develop and field-test drilling automation and robotics technologies for projected use in missions in the 2011-15 period. DAME includes control of the drilling hardware, and state estimation of both the hardware and the lithography being drilled and the state of the hole. A sister drill was constructed for the Mars Analog Río Tinto Experiment (MARTE) project and demonstrated automated core handling and string changeout in 2005 drilling tests at Rio Tinto, Spain. DAME focused instead on the problem of drill control while actively drilling while not getting stuck. Together, the DAME and MARTE projects demonstrate a fully automated robotic drilling capability, including hands-off drilling, adjustment to different strata and downhole conditions, recovery from drilling faults (binding, choking, etc.), drill string changeouts, core acquisition and removal, and sample handling and conveyance to in-situ instruments. The 2006 top-level goal of DAME drilling in-situ tests was to verify and demonstrate a capability for hands-off automated drilling, at an Arctic Mars-analog site. There were three sets of 2006 test goals, all of which were exceeded during the July 2006 field season. The first was to demonstrate the recognition, while drilling, of at least three of the six known major fault modes for the DAME planetary-prototype drill, and to employ the correct recovery or safing procedure in response. The second set of 2006 goals was to operate for three or more hours autonomously, hands-off. And the third 2006 goal was to exceed 3m depth into the frozen breccia and permafrost with the DAME drill (it had not gone further than 2.2m previously). Five of six faults were detected and corrected, there were 43 hours of hands-off drilling (including a 4 hour sequence with no human presence nearby), and 3.2m was the total depth. And ground truth drilling used small commercial drilling equipment in parallel in

  15. Contribution of water hyacinth (Eichhornia crassipes (Mart.) Solms) grown under different nutrient conditions to Fe-removal mechanisms in constructed wetlands.

    Jayaweera, Mahesh W; Kasturiarachchi, Jagath C; Kularatne, Ranil K A; Wijeyekoon, Suren L J

    2008-05-01

    Severe contamination of water resources including groundwater with iron (Fe) due to various anthropogenic activities has been a major environmental problem in industrial areas of Sri Lanka. Hence, the use of the obnoxious weed, water hyacinth (Eichhornia crassipes (Mart.) Solms) in constructed wetlands (floating aquatic macrophyte-based plant treatment systems) to phytoremediate Fe-rich wastewaters seems to be an appealing option. Although several studies have documented that hyacinths are good metal-accumulating plants none of these studies have documented the ability of this plant grown under different nutrient conditions to remove heavy metals from wastewaters. This paper, therefore, reports the phytoremediation efficiencies of water hyacinth grown under different nutrient conditions for Fe-rich wastewaters in batch-type constructed wetlands. This study was conducted for 15 weeks after 1-week acclimatization by culturing young water hyacinth plants (average height of 20+/-2cm) in 590L capacity fiberglass tanks under different nutrient concentrations of 1-fold [28 and 7.7mg/L of total nitrogen (TN) and total phosphorous (TP), respectively], 2-fold, 1/2-fold, 1/4-fold and 1/8-fold with synthetic wastewaters containing 9.27Femg/L. Another set-up of hyacinths containing only Fe as a heavy metal but without any nutrients (i.e., 0-fold) was also studied. A mass balance was carried out to investigate the phytoremediation efficiencies and to determine the different mechanisms governing Fe removal from the wastewaters. Fe removal was largely due to phytoremediation mainly through the process of rhizofiltration and chemical precipitation of Fe2O3 and FeOH3 followed by flocculation and sedimentation. However, chemical precipitation was more significant especially during the first 3 weeks of the study. Plants grown in the 0-fold set-up showed the highest phytoremediation efficiency of 47% during optimum growth at the 6th week with a highest accumulation of 6707Femg/kg dry

  16. Mechanisms of manganese removal from wastewaters in constructed wetlands comprising water hyacinth (Eichhornia crassipes (Mart.) Solms) grown under different nutrient conditions.

    Kularatne, Ranil K A; Kasturiarachchi, Jagath C; Manatunge, Jagath M A; Wijeyekoon, Suren L J

    2009-02-01

    This article discusses key mechanisms involved in removing 1 mg/L Mn from synthetic wastewaters in constructed wetlands comprising water hyacinth (Eichhornia crassipes (Mart.) Solms) grown under different nutrient levels of 1-fold (28 mg/L and 7.7 mg/L of total nitrogen and total phosphorus, respectively), 2-fold, 1/4-fold, and 1/8-fold. A mass balance was carried out to evaluate the key removal mechanisms. Phytoremediation mainly due to phytoextraction substantially contributed to manganese removal. However, chemical precipitation was absent, suggesting that manganese has a higher solubility in the given average pH (6.2 to 7.1) conditions in constructed wetlands. Bacterial mediated immobilization mechanisms also did not contribute to manganese removal. Sediments constituted a minor sink to manganese, implying that manganese has a poor adsorption potential. Constructed wetlands comprising water hyacinth are effective at removing manganese from wastewaters despite the fact that the plants are grown under higher or lower nutrient conditions. PMID:19323287

  17. Acquisition of teleological descriptions

    Franke, David W.

    1992-03-01

    Teleology descriptions capture the purpose of an entity, mechanism, or activity with which they are associated. These descriptions can be used in explanation, diagnosis, and design reuse. We describe a technique for acquiring teleological descriptions expressed in the teleology language TeD. Acquisition occurs during design by observing design modifications and design verification. We demonstrate the acquisition technique in an electronic circuit design.

  18. MICROBIAL ENZYME ACTIVITY FOR CHARACTERIZING NUTRIENT LOADING TO GREAT LAKES COASTAL WETLANDS

    Energy and material flows in aquatic ecosystems are mediated by microbial carbon and nutrient cycling. Extracellular enzymes produced by the microbial community aid in the degradation of organic matter and the resultant acquisition of limiting nutrients. Organic carbon sequestrat...

  19. Design and operation of the data acquisition and reduction system used in the applied mechanics division for mechanical tests and the post accident heat removal experiments

    This paper describes the design and use of a powerful data acquisition system based on a multi-user minicomputer. The system acquires data simultaneously from a number of different types of instruments and front-end microcomputers, performs some signal processing and generates alarm levels to the experimental plant, while running one or more programs (remote consoles) to provide presentations of the collected data in graphical form, or to support assignments of alarm values. A data base has been created and general programs for data manipulation, plotting and mathematical analysis have been written and documented. This work continues to provide more specialized computation for new applications. Essentially no knowledge of computers is required for data acquisition, file management and initiation of programs. This paper is divided into four parts: laboratory environment; system configuration; software potential; and basic criteria for reliable use of the system

  20. Nutrient-dependent/pheromone-controlled adaptive evolution: a model

    James Vaughn Kohl

    2013-06-01

    Full Text Available Background: The prenatal migration of gonadotropin-releasing hormone (GnRH neurosecretory neurons allows nutrients and human pheromones to alter GnRH pulsatility, which modulates the concurrent maturation of the neuroendocrine, reproductive, and central nervous systems, thus influencing the development of ingestive behavior, reproductive sexual behavior, and other behaviors. Methods: This model details how chemical ecology drives adaptive evolution via: (1 ecological niche construction, (2 social niche construction, (3 neurogenic niche construction, and (4 socio-cognitive niche construction. This model exemplifies the epigenetic effects of olfactory/pheromonal conditioning, which alters genetically predisposed, nutrient-dependent, hormone-driven mammalian behavior and choices for pheromones that control reproduction via their effects on luteinizing hormone (LH and systems biology. Results: Nutrients are metabolized to pheromones that condition behavior in the same way that food odors condition behavior associated with food preferences. The epigenetic effects of olfactory/pheromonal input calibrate and standardize molecular mechanisms for genetically predisposed receptor-mediated changes in intracellular signaling and stochastic gene expression in GnRH neurosecretory neurons of brain tissue. For example, glucose and pheromones alter the hypothalamic secretion of GnRH and LH. A form of GnRH associated with sexual orientation in yeasts links control of the feedback loops and developmental processes required for nutrient acquisition, movement, reproduction, and the diversification of species from microbes to man. Conclusion: An environmental drive evolved from that of nutrient ingestion in unicellular organisms to that of pheromone-controlled socialization in insects. In mammals, food odors and pheromones cause changes in hormones such as LH, which has developmental affects on pheromone-controlled sexual behavior in nutrient-dependent reproductively

  1. Linking Heterotrophic Metabolism and Nutrient Uptake in Headwater Streams

    Gray, Travis Michael

    2007-01-01

    Autotrophs and heterotrophs differ in their demand, acquisition and use of materials, but fundamentally nutrient demand is inherently linked to metabolism based on the stoichiometry of biochemical reactions. The differences between these two groups of organisms confound straightforward regression approaches to quantifying the relationship between nutrient demand and metabolism at an ecosystem level. We address how nutrient demand in headwater streams changes with shifts in organic matter su...

  2. Octopamine connects nutrient cues to lipid metabolism upon nutrient deprivation

    Tao, Jun; Ma, Yi-Cheng; Yang, Zhong-Shan; Zou, Cheng-Gang; Zhang, Ke-Qin

    2016-01-01

    Starvation is probably the most common stressful situation in nature. In vertebrates, elevation of the biogenic amine norepinephrine levels is common during starvation. However, the precise role of norepinephrine in nutrient deprivation remains largely unknown. We report that in the free-living nematode Caenorhabditis elegans, up-regulation of the biosynthesis of octopamine, the invertebrate counterpart of norepinephrine, serves as a mechanism to adapt to starvation. During nutrient deprivation, the nuclear receptor DAF-12, known to sense nutritional cues, up-regulates the expression of tbh-1 that encodes tyramine β-hydroxylase, a key enzyme for octopamine biosynthesis, in the RIC neurons. Octopamine induces the expression of the lipase gene lips-6 via its receptor SER-3 in the intestine. LIPS-6, in turn, elicits lipid mobilization. Our findings reveal that octopamine acts as an endocrine regulator linking nutrient cues to lipolysis to maintain energy homeostasis, and suggest that such a mechanism may be evolutionally conserved in diverse organisms. PMID:27386520

  3. Investigation of the mechanism of iron acquisition by the marine bacterium Alteromonas luteoviolaceus: Characterization of siderophore production

    Iron availability in the ocean ranges from one to four orders of magnitude below typical growth requirements of bacteria. The discrepancy between Fe availability and requirements raises questions about the mechanisms that marine bacteria use to sequester Fe3+. Surprisingly little is known about the siderophores produced by marine bacteria. Growth conditions of an open-ocean bacterial isolate, Alteromonas luteoviolaceus, were investigated to determine the conditions which enhance siderophore production. Methods to isolate and purify the siderophores were determined. The siderophores produced by A. luteoviolaceus were partially characterized by mass spectral analysis, amino acid analysis, qualitative analytical tests, chemical degradation, and nuclear magnetic resonance. A new set of outer membrane proteins was also produced when the bacterium was grown under Fe-limited conditions

  4. Knowledge Transfers following Acquisition

    Gammelgaard, Jens

    2001-01-01

    study of 54 Danish acquisitions taking place abroad from 1994 to 1998 demonstrated that when there was a high level of trust between the acquiring firm and the target firm before the take-over, then medium and strong tie-binding knowledge transfer mechanisms, such as project groups and job rotation...

  5. An integrated AMLAB-based system for acquisition, processing and analysis of evoked EMG and mechanical responses of upper limb muscles.

    Jaberzadeh, S; Nazeran, H; Scutter, S; Warden-Flood, A

    2003-06-01

    An integrated multi-channel AMLAB-based data acquisition, processing and analysis system has been developed to simultaneously display, quantify and correlate electromyographic (EMG) activity, resistive torque, range of motion, and pain responses evoked by passive elbow extension in humans. The system was designed around the AMLAB analog modules and software objects called ICAMs. Each channel consisted of a time and frequency domain block, a torque and angle measurement block, an experiment number counter block and a data storage and retrieval block. The captured data in each channel was used to display and quantify: raw EMG, rectified EMG, smoothed rectified EMG, root-mean-squared EMG, fast Fourier transformed (FFT) EMG, and normalized power spectrum density (NPSD) of EMG. Torque and angle signals representing elbow extension measured by a KIN-COM dynamometer during neural tension testing, as well as signals from an electronic pain threshold marker were interfaced to AMLAB and presented in one integrated display. Although this system has been designed to specifically study the patterns and nature of evoked motor responses during clinical investigation of carpal tunnel syndrome (CTS) patients, it could equally well be modified to allow acquisition, processing and analysis of EMG signals in other studies and applications. In this paper, we present for the first time the steps involved in the design, implementation and testing of an integrated AMLAB-based system to study and analyse the mechanically evoked electromyographic, torque and ROM signals and correlate various levels of pain to these signals. We also present samples of resistive torque ROM, and raw and processed EMG recordings during passive elbow extension. PMID:12956188

  6. Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: why variations in bilingual experiences matter.

    Yow, W Quin; Li, Xiaoqian

    2015-01-01

    Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English-Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number-letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number-letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting. PMID:25767451

  7. Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: Why variations in bilingual experiences matter.

    W. Quin eYow

    2015-02-01

    Full Text Available Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-year-old English-Mandarin bilinguals performed four computerized executive function tasks (Stroop, Eriksen flanker, number-letter switching and n-back task that measure the executive function components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages on the Stroop and number-letter task (mixing cost only, indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related executive functions such as inhibiting prepotent responses and global

  8. The role of arbuscular mycorrhizas in reducing soil nutrient loss.

    Cavagnaro, Timothy R; Bender, S Franz; Asghari, Hamid R; Heijden, Marcel G A van der

    2015-05-01

    Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular mycorrhizas (AM), associations of plant roots with fungi that acquire soil nutrients. There is emerging evidence that AM have the ability to reduce nutrient loss from soils by enlarging the nutrient interception zone and preventing nutrient loss after rain-induced leaching events. Until recently, this important ecosystem service of AM had been largely overlooked. Here we review the role of AM in reducing nutrient loss and conclude that this role cannot be ignored if we are to increase global food production in an environmentally sustainable manner. PMID:25840500

  9. A new electrical and mechanically detonatable shear wave source for near surface (0-30 m) seismic acquisition

    Crane, J. M.; Lorenzo, J. M.; Harris, J. B.

    2013-04-01

    We present a new, impulsive, horizontal shear source capable of performing long shot profiles in a time-efficient and repeatable manner. The new shear source is ground-coupled by eight 1/2″ (1.27 cm) × 2″ (5.08 cm) steel spikes. Blank shotshells (12-gauge) used as energy sources can be either mechanically or electrically detonated. Electrical fuses have a start time repeatability of hammer blows. To ensure complete safety, the shotshell holder is surrounded by a protective 6″ (15.24 cm)-thick barrel, a push-and-twist-locked breach, and a safety pin. We conducted field tests at the 17th Street Canal levee breach site in New Orleans, Louisiana (30.017° N 90.121° W) and at an instrumented test borehole at Millsaps College in Jackson, Mississippi (32.325° N 93.182° W) to compare our new source and a traditional hammer impact source. The new shear source produces a broader-band of frequencies (30-100 Hz cf. 30-60 Hz). Signal generated by the new shear source has signal-to-noise ratios equivalent to ~ 3 stacked hammer blows to the hammer impact source. Ideal source signals must be broadband in frequency, have a high SNR, be consistent, and have precise start times; all traits of the new shear source.

  10. Mergers & Acquisitions

    Fomcenco, Alex

    This dissertation is a legal dogmatic thesis, the goal of which is to describe and analyze the current state of law in Europe in regard to some relevant selected elements related to mergers and acquisitions, and the adviser’s counsel in this regard. Having regard to the topic of the dissertation...

  11. Enhancing nutrient management through use of isotope techniques

    Enhanced nutrient cycling basically involves close interaction between inorganic and organic sources of nutrients. Contrasting scenarios of nutrient cycling are found under intensive cropping production systems in most industrialized countries and traditional production systems predominant in many developing countries, where there is a net mining of soil nutrients due to crop harvest removal and erosion. Therefore, to enhance nutrient management in marginal tropical soils it is necessary to maximize the efficiency of nutrient uptake from various inorganic and organic sources with minimal environmental impact. It is postulated that one of the main approaches will be the identification and/or selection of plant genotypes for enhanced nutrient acquisition, in particular at low levels of soil available nutrients. In this context, use of various isotope techniques in examining root activity/distribution pattern and plant nutrient uptake is examined. On the other hand, the need for developing integrated plant nutrition systems is stressed. Past and present uses of the isotopic method by direct and indirect approaches in nutrient uptake from both inorganic and organic sources are reviewed. Special reference is made to the results of FAO/IAEA Co-ordinated Research Programmes. Potential uses of isotopic tracers in nutrient cycling studies and for enhancing nutrient uptake efficiency in integrated plant nutrition systems are indicated. (author). 59 refs, 3 figs, 8 tabs

  12. New insights into carbon acquisition and exchanges within the coral-dinoflagellate symbiosis under NH4+ and NO3- supply.

    Ezzat, Leïla; Maguer, Jean-François; Grover, Renaud; Ferrier-Pagès, Christine

    2015-08-01

    Anthropogenic nutrient enrichment affects the biogeochemical cycles and nutrient stoichiometry of coastal ecosystems and is often associated with coral reef decline. However, the mechanisms by which dissolved inorganic nutrients, and especially nitrogen forms (ammonium versus nitrate) can disturb the association between corals and their symbiotic algae are subject to controversial debate. Here, we investigated the coral response to varying N : P ratios, with nitrate or ammonium as a nitrogen source. We showed significant differences in the carbon acquisition by the symbionts and its allocation within the symbiosis according to nutrient abundance, type and stoichiometry. In particular, under low phosphate concentration (0.05 µM), a 3 µM nitrate enrichment induced a significant decrease in carbon fixation rate and low values of carbon translocation, compared with control conditions (N : P = 0.5 : 0.05), while these processes were significantly enhanced when nitrate was replaced by ammonium. A combined enrichment in ammonium and phosphorus (N : P = 3 : 1) induced a shift in nutrient allocation to the symbionts, at the detriment of the host. Altogether, these results shed light into the effect of nutrient enrichment on reef corals. More broadly, they improve our understanding of the consequences of nutrient loading on reef ecosystems, which is urgently required to refine risk management strategies. PMID:26203006

  13. Choosing Nutrient Dense Foods

    Full Text Available ... are high in nutrients and low in calories. Eating this way is especially important as you age. ... nutrients and not empty calories. Narrator: This means eating foods that contain vitamins, minerals, complex carbohydrates, lean ...

  14. Choosing Nutrient Dense Foods

    Full Text Available ... variety of nutrients from a variety of food groups. A balanced approach is best. Narrator: Dietary guidelines ... your daily calorie level. Each of the food groups contains a variety of beneficial nutrients. For example, ...

  15. Choosing Nutrient Dense Foods

    Full Text Available ... Bales, Ph.D., R.D.: So what nutrient density does is allow you to choose between closely ... enough calories for the day, either way, nutrient density is a very important concept.

  16. Choosing Nutrient Dense Foods

    Full Text Available ... beneficial nutrients. For example, fruits and vegetables not only offer important vitamins and minerals, but also provide ... ingredient of a nutrient-dense diet. They not only provide vitamins and minerals but also fiber. Dr. ...

  17. Improving crop nutrient efficiency through root architecture modifications.

    Li, Xinxin; Zeng, Rensen; Liao, Hong

    2016-03-01

    Improving crop nutrient efficiency becomes an essential consideration for environmentally friendly and sustainable agriculture. Plant growth and development is dependent on 17 essential nutrient elements, among them, nitrogen (N) and phosphorus (P) are the two most important mineral nutrients. Hence it is not surprising that low N and/or low P availability in soils severely constrains crop growth and productivity, and thereby have become high priority targets for improving nutrient efficiency in crops. Root exploration largely determines the ability of plants to acquire mineral nutrients from soils. Therefore, root architecture, the 3-dimensional configuration of the plant's root system in the soil, is of great importance for improving crop nutrient efficiency. Furthermore, the symbiotic associations between host plants and arbuscular mycorrhiza fungi/rhizobial bacteria, are additional important strategies to enhance nutrient acquisition. In this review, we summarize the recent advances in the current understanding of crop species control of root architecture alterations in response to nutrient availability and root/microbe symbioses, through gene or QTL regulation, which results in enhanced nutrient acquisition. PMID:26460087

  18. The design and validation of a magnetic resonance imaging-compatible device for obtaining mechanical properties of plantar soft tissue via gated acquisition.

    Williams, Evan D; Stebbins, Michael J; Cavanagh, Peter R; Haynor, David R; Chu, Baocheng; Fassbind, Michael J; Isvilanonda, Vara; Ledoux, William R

    2015-10-01

    Changes in the mechanical properties of the plantar soft tissue in people with diabetes may contribute to the formation of plantar ulcers. Such ulcers have been shown to be in the causal pathway for lower extremity amputation. The hydraulic plantar soft tissue reducer (HyPSTER) was designed to measure in vivo, rate-dependent plantar soft tissue compressive force and three-dimensional deformations to help understand, predict, and prevent ulcer formation. These patient-specific values can then be used in an inverse finite element analysis to determine tissue moduli, and subsequently used in a foot model to show regions of high stress under a wide variety of loading conditions. The HyPSTER uses an actuator to drive a magnetic resonance imaging-compatible hydraulic loading platform. Pressure and actuator position were synchronized with gated magnetic resonance imaging acquisition. Achievable loading rates were slower than those found in normal walking because of a water-hammer effect (pressure wave ringing) in the hydraulic system when the actuator direction was changed rapidly. The subsequent verification tests were, therefore, performed at 0.2 Hz. The unloaded displacement accuracy of the system was within 0.31%. Compliance, presumably in the system's plastic components, caused a displacement loss of 5.7 mm during a 20-mm actuator test at 1354 N. This was accounted for with a target to actual calibration curve. The positional accuracy of the HyPSTER during loaded displacement verification tests from 3 to 9 mm against a silicone backstop was 95.9% with a precision of 98.7%. The HyPSTER generated minimal artifact in the magnetic resonance imaging scanner. Careful analysis of the synchronization of the HyPSTER and the magnetic resonance imaging scanner was performed. With some limitations, the HyPSTER provided key functionality in measuring dynamic, patient-specific plantar soft tissue mechanical properties. PMID:26405098

  19. Integration of root phenes for soil resource acquisition

    Larry Matthew York

    2013-09-01

    Full Text Available Suboptimal availability of water and nutrients is a primary limitation to plant growth in terrestrial ecosystems. The acquisition of soil resources by plant roots is therefore an important component of plant fitness and agricultural productivity. Plant root systems comprise a set of phenes, or traits, that interact. Phenes are the units of the plant phenotype, and phene states represent the variation in form and function a particular phene may take. Root phenes can be classified as affecting resource acquisition or utilization, influencing acquisition through exploration or exploitation, and in being metabolically influential or neutral. These classifications determine how one phene will interact with another phene, whether through foraging mechanisms or metabolic economics. Phenes that influence one another through foraging mechanisms are likely to operate within a phene module, a group of interacting phenes, that may be co-selected. Examples of root phene interactions discussed are: 1 root hair length × root hair density, 2 lateral branching × root cortical aerenchyma, 3 adventitious root number × adventitious root respiration and basal root growth angle, 4 nodal root number × root cortical aerenchyma, and 5 basal root growth angle × root hair length and density. Progress in the study of phenes and phene interactions will be facilitated by employing simulation modeling and near-isophenic lines that allow the study of specific phenes and phene combinations within a common phenotypic background. Developing a robust understanding of the phenome at the organismal level will require new lines of inquiry into how phenotypic integration influences plant function in diverse environments. A better understanding of how root phenes interact to affect soil resource acquisition will be an important tool in the breeding of crops with superior stress tolerance and reduced dependence on intensive use of inputs.

  20. 2015 NAIP Acquisition Map

    Farm Service Agency, Department of Agriculture — Planned States for 2015 NAIP acquisition and acquisition status layer (updated daily). Updates to the acquisition seasons may be made during the season to...

  1. 2016 NAIP Acquisition Map

    Farm Service Agency, Department of Agriculture — Planned States for 2016 NAIP acquisition and acquisition status layer (updated daily). Updates to the acquisition seasons may be made during the season to...

  2. Nutrient acquisition and secondary metabolites in plant pathogenic fungi

    Droce, Aida

    Fusarium graminearum is a necrotrophic plant pathogen that leads to severe infections of cereals contaminating them with mycotoxins harmful to human and animal. Blumeria graminis f. sp. hordei is an obligate biotroph that causes powdery mildew infections of barley. In this thesis, lifecycles and ...

  3. Improving Acquisition Outcomes with Contextual Ambidexterity

    Meglio, Olimpia; King, David R.; Risberg, Annette

    The results of research on mergers and acquisitions often point to a need to improve acquisition outcomes and lessen the organizational turmoil that can often follow integration efforts. We assert that viewing acquisition integration through the lens of contextual ambidexterity may improve...... acquisition outcomes in two ways: by providing an integrated solution to the economic and social tensions in acquisitions, and by enabling managers to effectively confront the competing needs of task and human integration. We also posit that by building on contextual ambidexterity, we can extend the...... possibilities for both research and practice regarding task and human integration in acquisitions. We also emphasize the role of an integration manager and integration mechanisms in enabling contextual ambidexterity for successful acquisition integration. Finally, we identify implications for research and...

  4. Choosing Nutrient Dense Foods

    Full Text Available ... consume, it’s important to think about the nutrient value of the foods you eat. Dr. Connie W. ... foods, the one that is the best nutritional value for you. So for 100 calories that you ...

  5. Choosing Nutrient Dense Foods

    Full Text Available ... you eat. Are they primarily nutrient-dense, like these, [ photos of melon, red bell pepper, oatmeal ] or are they mostly calorie dense, like these? [ photos of butter crackers, bacon, coffee cake ] Some ...

  6. Choosing Nutrient Dense Foods

    Full Text Available ... of butter crackers, bacon, coffee cake ] Some older adults answer the question this way: Richard: In the ... is okay. Narrator: Richard and Gloria are older adults who choose to eat nutrient-dense foods, foods ...

  7. Choosing Nutrient Dense Foods

    Full Text Available ... like processed meats and go for lean, freshly cooked meats. Narrator: Consider varying your sources of protein ... to think about the nutrient value of the foods you eat. Dr. Connie W. Bales, Ph.D., ...

  8. Choosing Nutrient Dense Foods

    Full Text Available ... eat. Are they primarily nutrient-dense, like these, [ photos of melon, red bell pepper, oatmeal ] or are they mostly calorie dense, like these? [ photos of butter crackers, bacon, coffee cake ] Some older ...

  9. Choosing Nutrient Dense Foods

    Full Text Available ... coffee cake ] Some older adults answer the question this way: Richard: In the summertime, like now, fruit ... high in nutrients and low in calories. Eating this way is especially important as you age. Dr. ...

  10. Choosing Nutrient Dense Foods

    Full Text Available ... eat lots of them every day, usually in dishes that Richard prepares. Richard: When we are eating ... 100 calories that you obtain from a fruit dish, you might have only a few nutrients and ...

  11. Choosing Nutrient Dense Foods

    Full Text Available ... put some cheese in it. And with my diet, an ounce of cheese is okay. Narrator: Richard ... of all ages, older adults should consume a diet that includes a variety of nutrients from a ...

  12. Nutrient Driven Topology Optimization

    Satha, Ganarupan

    2010-01-01

    The aim of this thesis is to investigate how a biological structure changes its shape and boundary under different cases of load if flow of nutrients is included, since nutrient flow has not been taken into account in previous studies. In order to simulate such a scenario we construct a model by using topology optimization (the SIMP model) and a balance law which is suitable for biological structures. Moreover, the model is derived by using an analogy with the dissipation inequality and Colem...

  13. Interplay of nutrients and microbial metabolites in intestinal immune homeostasis: distinct and common mechanisms of immune regulation in the small bowel and colon.

    Perrigoue, Jacqueline; Das, Anuk; Mora, J Rodrigo

    2014-01-01

    The intestinal mucosa is the largest body surface exposed to the environment. While there are common features when comparing immune responses along the intestinal mucosa, the small bowel and colon exhibit striking differences in their mechanisms driving immune regulation. The vitamin A (VA) metabolite all-trans retinoic acid (RA) signaling via RA nuclear receptors plays a key role in immune homeostasis in the small bowel, and recent work indicates that RA is required for establishing immune tolerance to dietary antigens in the upper intestinal tract by inducing α4β7(+)CCR9(+) gut-tropic TREG. In contrast, microbiota-specific TREG in the colon do not appear to require RA, but can be regulated by short-chain fatty acids (SCFA), microbial metabolites that signal through the G protein-coupled receptor GPR43. Moreover, TREG do not need CCR9 to home to the colon, but utilize another G protein-coupled receptor, GPR15, which is upregulated by SCFA. Thus, the mechanisms governing intestinal tolerance to dietary antigens in the upper digestive tract differ from those controlling tolerance to the microbiota in the colon, with RA and SCFA playing key complementary roles in their respective compartments. In addition to VA and SCFA, recent studies have highlighted the roles of other dietary and microbial metabolites that influence immune cell homeostasis across the small and large bowel including dietary ligands for aryl hydrocarbon receptor and microbiota-modified bile acids. Understanding the complex and dynamic interplay between dietary metabolites and commensal microbiota within the intestinal microenvironment could therefore inform novel strategies for the treatment of food allergies and inflammatory bowel diseases. PMID:25227295

  14. Data acquisition

    From the inception of the International Cooperative Group on Cyclic Crack Growth (ICCGR), it was recognised that its main objective was ultimately to provide a reliable and consistent data base on environmental cracking rates in pressure vessel steels, together with suitable analysis, as a basis for improvements or modification as required of ASME Section XI Appendix A. Therefore, a forum was provided for presentation of new experimental results from corrosion fatigue and stress corrosion crack growth experiments in Task Group I. This enabled early opportunity to peer review, a chance to see how individual laboratory results fitted into the developing international picture, opportunity to redirect national programmes more precisely on to areas of greatest uncertainty and to provide the raw material for the Mechanisms and Applications task groups to work with. Over the last 10 years, there has been a gradual shift of emphasis. In the early years, much effort was devoted to the development of acceptable testing practices such as monitoring techniques for remotely sensing crack extension in specimens contained in autoclaves and for checking the environmental conditions experienced by the test specimens. Latterly, experimental work has been clearly focused on the principal parameters affecting environmental cracking rates, notably steel sulphur content and morphology. The main achievements in these areas are reviewed below, highlighting the main points from earlier reviews and developments since. (author)

  15. Relevance of nutrient media composition for hydrogen production in Chlamydomonas.

    Gonzalez-Ballester, David; Jurado-Oller, Jose Luis; Fernandez, Emilio

    2015-09-01

    Microalgae are capable of biological H2 photoproduction from water, solar energy, and a variety of organic substrates. Acclimation responses to different nutrient regimes finely control photosynthetic activity and can influence H2 production. Hence, nutrient stresses are an interesting scenario to study H2 production in photosynthetic organisms. In this review, we mainly focus on the H2-production mechanisms in Chlamydomonas reinhardtii and the physiological relevance of the nutrient media composition when producing H2. PMID:25952745

  16. Developing a nutrient recovery process for recovering nutrients in anaerobic digestate in low income countries

    Rose, Christopher

    2015-01-01

    It is estimated that 2.7 billion people worldwide are served by on-site sanitation facilities that require faecal sludge management. Anaerobic digestion is a treatment mechanism that can provide faecal sludge management, methane production and an effluent digestate rich in nutrients. However, there is a paucity of information regarding the composition of the input faecal sludge which hinders the advancement of anaerobic digestion treatment and downstream nutrient recovery to...

  17. Glutamate prevents intestinal atrophy via luminal nutrient sensing in a mouse model of total parenteral nutrition

    Xiao, Weidong; Feng, Yongjia; Holst, Jens Juul;

    2014-01-01

    Small intestine luminal nutrient sensing may be crucial for modulating physiological functions. However, its mechanism of action is incompletely understood. We used a model of enteral nutrient deprivation, or total parenteral nutrition (TPN), resulting in intestinal mucosal atrophy and decreased...

  18. Language Acquisition without an Acquisition Device

    O'Grady, William

    2012-01-01

    Most explanatory work on first and second language learning assumes the primacy of the acquisition phenomenon itself, and a good deal of work has been devoted to the search for an "acquisition device" that is specific to humans, and perhaps even to language. I will consider the possibility that this strategy is misguided and that language…

  19. Choosing Nutrient Dense Foods

    Full Text Available ... variety of beneficial nutrients. For example, fruits and vegetables not only offer important vitamins and minerals, but also provide phytochemicals, natural compounds like beta carotene and lycopene that may promote good health. Dr. Connie W. Bales, Ph.D., R.D.: ...

  20. Choosing Nutrient Dense Foods

    Full Text Available Narrator: Think about the foods you eat. Are they primarily nutrient-dense, like these, [ photos of melon, red bell pepper, oatmeal ] or are ... crackers, bacon, coffee cake ] Some older adults answer the question this way: Richard: In the summertime, like ...

  1. Choosing Nutrient Dense Foods

    Full Text Available Narrator: Think about the foods you eat. Are they primarily nutrient-dense, like these, [ photos of melon, red bell pepper, oatmeal ] or are they mostly ... the summertime, like now, fruit is my favorite food. So I eat probably more fruit than anything ...

  2. Calo trigger acquisition system

    Franchini, Matteo

    2016-01-01

    Calo trigger acquisition system - Evolution of the acquisition system from a multiple boards system (upper, orange cables) to a single board one (below, light blue cables) where all the channels are collected in a single board.

  3. 油茶苗期生物量积累及营养分配规律研究%Mechanism of biomass accumulation and nutrient distribution in Camellia oleifera at seedling growth stage

    唐健; 李娜; 欧阳洁英; 曹继钊; 覃其云

    2011-01-01

    [Objective]The present experiment was conducted to study the mechanism of biomass accumulation and distribution of nutrients in Camellia oleifera at seedling growth stage. [ Method ]The growth indicators and biomass and nutrient contents of leaf, stem and root of 150 Camellia oleifera plants were determined at seedling growth stage. [Result]The results showed higher biomass in aboveground plant parts, amongst which leaves had the highest biomass accumulation. The seedlings were grouped into various grades according to their length, amongst these groups, the seedlings with height ranging from 14.00-15.90 cm were highest in number (38.67%) and their biomass occupied the highest percentage (34.19%). The root, stem, and leaves of plant were found to accumulate highest N content, followed by K and Ca contents, Cu and B were the lowest. The N and Mn contents showed highest accumulation in leaves, while P, K, Cu, Zn, Fe and B contents accumulated more in the roots. The variance analysis results indicated significant differences in N, K, Mg, Cu, Mn and B contents in root, stem and leaves. [Conclusion]The leaf of Camellia oleifera had the highest biomass at seedling stage and the plant biomass increased significantly with the growth of seedlings. Significantly different uptake and accumulation of different nutrient elements in root, stem and leaves will help in understanding the growth and development of Camellia oleifera in relation to particular element, and provide the reference on fertilization at seedling stage.%了解油茶苗期不同器官生物量积累及营养元素分布情况.对150株油茶苗期各种生长性状指标、生物量及营养元素含量进行测定.油茶苗期各单株生物量均以地上部分占绝对优势,其中叶片生物量积累最高;不同苗高分级苗木株数及其生物量近似于正态分布,其中14.00~15.90 cm苗高分级株数和生物量百分比最高,分别为38.67%和34.19%.在油茶根、茎、叶中均以N

  4. 城市偏向视角下的征地价格扭曲:机理、测度与特征%Distortion of Land Acquisition Price from the Perspective of Urban Bias: Mechanism, Measurement, and Features

    谭术魁; 王斯亮

    2015-01-01

    The purpose of this paper is to clarify the mechanism of distortion of land acquisition price, then to measure distortion degrees of the nation, three regions, and 18 provincial-level administrative regions from 2005 to 2011, and at last to analyze characteristics and its influence factors. Methods include statistical models, comparative analysis, and econometric analysis. Research results show that: 1)the distortion of land acquisition price is a policy tool which is formed in the institution soil of urban-rural land flow controlled, and is to serve the endogenous development logic of urban bias; 2)the distortion of land acquisition price showed a fluctuated upward trend, rose from 80.94% in 2005 to 88.00% in 2011, the main reason for increase was that the conversion market value of agricultural land grew faster than the land acquisition price; 3)there were also obvious regional differences in the distortion of land acquisition price, that is the Eastern Region was high-level and high growth, the Central Region was relative high level but low growth, no regularity inthe Western Region, but the differences was first expanded till 2008 then narrowed; 4)the degree of distortion increases with the development of economy and land lease market, while adjusting the compensation standard for accelerating land acquisition market reform, and increasing land acquisition amount through new urban construction land planning, both are helpful to mitigate distortion. The research concludes that existing methods to improve the land acquisition compensation standards for mitigating the distortion of land acquisition price was somehow useless, the fundamental policy is to get rid of the development concept of urban bias, to promote market-oriented reform of rural land and the form of a unified urban and rural construction land market, at the same time to explore how to construct the dynamic adjustment mechanism for land acquisition compensation linked with state-owned construction

  5. Plant nutrient transporter regulation in arbuscular mycorrhizas

    Burleigh, Stephen; Bechmann, I.E.

    2002-01-01

    This review discusses the role arbuscular mycorrhizal fungi play in the regulation of plant nutrient transporter genes. Many plant nutrient transporter genes appear to be transcriptionally regulated by a feed-back mechanism that reduces their expression when the plant reaches an optimal level of...... nutrition. Their down-regulation in mycorrhizal roots, therefore, would be predicted as a result of symbiotic function. A variety of studies on Pi- Zn- and ammonium- or nitrate-transporter genes from two plant species indirectly support this model. For example, one study showed that the expression of the...... high-affinity Pi-transporter MtPT2 within mycorrhizal roots of Medicago truncatula was inversely correlated with the concentration of P within the shoots, which suggested that P supply from the fungus influenced this gene's expression. However, there is some evidence that these plant nutrient...

  6. Insects, infestations and nutrient fluxes

    Michalzik, B.

    2012-04-01

    Forest ecosystems are characterized by a high temporal and spatial variability in the vertical transfer of energy and matter within the canopy and the soil compartment. The mechanisms and controlling factors behind canopy processes and system-internal transfer dynamics are imperfectly understood at the moment. Seasonal flux diversities and inhomogeneities in throughfall composition have been reported from coniferous and deciduous forests, and in most cases leaf leaching has been considered as principle driver for differences in the amount and quality of nutrients and organic compounds (Tukey and Morgan 1963). Since herbivorous insects and the processes they initiate received less attention in past times, ecologists now emphasize the need for linking biological processes occurring in different ecosystem strata to explain rates and variability of nutrient cycling (Bardgett et al. 1998, Wardle et al. 2004). Consequently, herbivore insects in the canopies of forests are increasingly identified to play an important role for the (re)cycling and availability of nutrients, or, more generally, for the functioning of ecosystems not only in outbreak situations but also at endemic (non-outbreak) density levels (Stadler et al. 2001, Hunter et al. 2003). Before, little attention was paid to insect herbivores when quantifying element and energy fluxes through ecosystems, although the numerous and different functions insects fulfill in ecosystems (e.g. as pollinators, herbivores or detritivores) were unanimously recognized (Schowalter 2000). Amongst the reasons for this restraint was the argument that the total biomass of insects tends to be relatively low compared to the biomass of trees or the pool of soil organic matter (Ohmart et al. 1983). A second argument which was put forward to justify the inferior role of insects in nutrient cycling were the supposed low defoliation losses between 5-10% of the annual leaf biomass, or net primary production, due to insect herbivory under

  7. Maternal Voluntary Exercise during Pregnancy Enhances the Spatial Learning Acquisition but not the Retention of Memory in Rat Pups via a TrkB-mediated Mechanism: The Role of Hippocampal BDNF Expression

    Maziar M Akhavan

    2013-09-01

    Full Text Available   Objective(s: The effect of maternal voluntary exercise on hippocampal BDNF level in rat offspring was studied. In addition, the possible role of hippocampal BDNF receptors in maternal exercise induced enhancement of learning in the rat pups was investigated.   Materials and Methods: Pregnant rats have been randomly assigned to sedentary control or voluntary exercise groups. Each of the exercising pregnant rats was given access to a cage that was equipped with a running wheel until the end of their pregnancy. On post natal day (PND 36, two groups consisted of 7 male rat pups in each group from sedentary or exercised mothers were sacrificed and the hippocampus was dissected for BDNF proteins level determination. Also, bilateral injection of K252a to the hippocampus was used to block the hippocampal BDNF action on PND59 in the rat pups. Results: Voluntary exercise during pregnancy significantly increased the level of BDNF protein in the hippocampus of the rat pups on PND36 compared to the control group (P=0.048. Inhibiting BDNF action abolished the exercise-induced improvement of learning acquisition in offspring in training trials (P=0.0001. No difference was observed in the platform location latency and the time spent in the target in the probe test between two groups. Conclusion : This study demonstrates that voluntary exercise during pregnancy via a TrkB-mediated mechanism enhances the spatial learning acquisition, however, not the retention of memory in the rat pups.

  8. Acclimation of Emiliania huxleyi (1516) to nutrient limitation involves precise modification of the proteome to scavenge alternative sources of N and P.

    McKew, Boyd A; Metodieva, Gergana; Raines, Christine A; Metodiev, Metodi V; Geider, Richard J

    2015-10-01

    Limitation of marine primary production by the availability of nitrogen or phosphorus is common. Emiliania huxleyi, a ubiquitous phytoplankter that plays key roles in primary production, calcium carbonate precipitation and production of dimethyl sulfide, often blooms in mid-latitude at the beginning of summer when inorganic nutrient concentrations are low. To understand physiological mechanisms that allow such blooms, we examined how the proteome of E. huxleyi (strain 1516) responds to N and P limitation. We observed modest changes in much of the proteome despite large physiological changes (e.g. cellular biomass, C, N and P) associated with nutrient limitation of growth rate. Acclimation to nutrient limitation did however involve significant increases in the abundance of transporters for ammonium and nitrate under N limitation and for phosphate under P limitation. More notable were large increases in proteins involved in the acquisition of organic forms of N and P, including urea and amino acid/polyamine transporters and numerous C-N hydrolases under N limitation and a large upregulation of alkaline phosphatase under P limitation. This highly targeted reorganization of the proteome towards scavenging organic forms of macronutrients gives unique insight into the molecular mechanisms that underpin how E. huxleyi has found its niche to bloom in surface waters depleted of inorganic nutrients. PMID:26119724

  9. Bone nutrients for vegetarians.

    Mangels, Ann Reed

    2014-07-01

    The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health. PMID:24898231

  10. National Nutrient Database for Standard Reference - Find Nutrient Value of Common Foods by Nutrient

    United States Department of Agriculture Agricultural Research Service National Nutrient Database for Standard Reference Release 28 NDL Home Food ... Food Groups: Sort by: Measure by: * required field ​ National Nutrient Database for Standard Reference Release 28 slightly revised May, ...

  11. Research of the fluorescence detection apparatus for nutrients

    Wang, Yu; Yan, Huimin; Ni, Xuxiang; Xu, Xiaoyi; Chen, Shibing

    2015-10-01

    The research of the multifunctional analyzer of Clinical Nutrition, which integrates the absorbance, luminescence, fluorescence and other optical detection methods, can overcome the functional limitations of a single technology on human nutrition analysis, and realize a rapid and accurate analysis of the nutrients. This article focuses on the design of fluorescence detection module that uses a photomultiplier tube(PMT) to detect weak fluorescence, and utilizes the single photon counting method to measure the fluorescence intensity, and then according to the relationship between the fluorescent marker and fluorescence intensity, the concentration of the analyte can be derived. Using fluorescein isothiocyanate(FITC, the most widely used fluorescein currently)to mark antibodies in the experiment, therefore, according to the maximum absorption wavelength and the maximum emission wavelength of the fluorescein isothiocyanate, to select the appropriate filters to set up the optical path. In addition, the fluorescence detection apparatus proposed in this paper uses an aspherical lens with large numerical aperture, in order to improve the capacity of signal acquisition more effectively, and the selective adoption of flexible optical fiber can realize a compact opto-mechanical structure, which is also conducive to the miniaturization of the device. The experimental results show that this apparatus has a high sensitivity, can be used for the detection and analysis of human nutrition.

  12. Technological Similarity, Post-acquisition R&D Reorganization, and Innovation Performance in Horizontal Acquisition

    Colombo, Massimo G.; Rabbiosi, Larissa

    2014-01-01

    This paper aims to disentangle the mechanisms through which technological similarity between acquiring and acquired firms influences innovation in horizontal acquisitions. We develop a theoretical model that links technological similarity to: (i) two key aspects of post-acquisition reorganization...... of acquired R&D operations – the rationalization of the R&D operations and the replacement of the R&D top manager, and (ii) two intermediate effects that are closely associated with the post-acquisition innovation performance of the combined firm – improvements in R&D productivity and disruptions in...... R&D personnel. We rely on PLS techniques to test our theoretical model using detailed information on 31 horizontal acquisitions in high- and medium-tech industries. Our results indicate that in horizontal acquisitions, technological similarity negatively affects post-acquisition innovation...

  13. Plants adapted to nutrient limitation allocate less biomass into stems in an arid-hot grassland.

    Yan, Bangguo; Ji, Zhonghua; Fan, Bo; Wang, Xuemei; He, Guangxiong; Shi, Liangtao; Liu, Gangcai

    2016-09-01

    Biomass allocation can exert a great influence on plant resource acquisition and nutrient use. However, the role of biomass allocation strategies in shaping plant community composition under nutrient limitations remains poorly addressed. We hypothesized that species-specific allocation strategies can affect plant adaptation to nutrient limitations, resulting in species turnover and changes in community-level biomass allocations across nutrient gradients. In this study, we measured species abundance and the concentrations of nitrogen and phosphorus in leaves and soil nutrients in an arid-hot grassland. We quantified species-specific allocation parameters for stems vs leaves based on allometric scaling relationships. Species-specific stem vs leaf allocation parameters were weighted with species abundances to calculate the community-weighted means driven by species turnover. We found that the community-weighted means of biomass allocation parameters were significantly related to the soil nutrient gradient as well as to leaf stoichiometry, indicating that species-specific allocation strategies can affect plant adaptation to nutrient limitations in the studied grassland. Species that allocate less to stems than leaves tend to dominate nutrient-limited environments. The results support the hypothesis that species-specific allocations affect plant adaptation to nutrient limitations. The allocation trade-off between stems and leaves has the potential to greatly affect plant distribution across nutrient gradients. PMID:27101947

  14. Rhizosphere priming: a nutrient perspective

    Feike Auke Dijkstra; Yolima eCarrillo; Elise ePendall; Morgan, Jack A.

    2013-01-01

    Rhizosphere priming is the change in decomposition of soil organic matter (SOM) caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C) dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply i...

  15. Robotization in Seismic Acquisition

    Blacquière, G.; Berkhout, A.J.

    2013-01-01

    The amount of sources and detectors in the seismic method follows "Moore’s Law of seismic data acquisition", i.e., it increases approximately by a factor of 10 every 10 years. Therefore automation is unavoidable, leading to robotization of seismic data acquisition. Recently, we introduced a new sour

  16. Firm Acquisitions Strategy

    Conf.univ.dr.ec. Adrian SIMON,

    2010-01-01

    We analyze the intents of acquiring firms and target in the firms in the case of thirty recent M$A deals involving at least one firm. The findings indicate that horizontal acquisitions help retain or gain market leadership. Market entry may be a dominant motive for MNCs acquiring domestic firms, and MNCs may offer higher premiums than domestic acquirers for the acquisition

  17. Data acquisition system

    The topic of this paper deals with a multi parametric acquisition system developed around a four input Analog to Digital Converter working in CAMAC Standard. The acquisition software is built in MS Visual C++ on a standard PC with a USB interface. It has a visual interface which permits Start/Stop of the acquisition, setting the type of acquisition (True/Live time), the time and various menus for primary data acquisition. The spectrum is dynamically visualized with a moving cursor indicating the content and position. The microcontroller PIC16C765 is used for data transfer from ADC to PC; The microcontroller and the software create an embedded system which emulates the CAMAC protocol programming, the 4 input ADC for operating modes ('zero suppression', 'addressed' and 'sequential') and handling the data transfers from ADC to its internal memory. From its memory the data is transferred into the PC by the USB interface. The work is in progress. (authors)

  18. Nutrient Cycling Study

    Peter A. Pryfogle

    2005-09-01

    The particular goal of this study is to develop measurement techniques for understanding how consortia of organisms from geothermal facilities utilize sulfur and iron for metabolic activity; and in turn, what role that activity plays in initiating or promoting the development of a biofilm on plant substrates. Sulfur cycling is of interest because sulfur is produced in the resource. Iron is found in some of the steel formulations used in plant components and is also added as chemical treatment for reducing sulfide emissions from the plants. This report describes the set-up and operation of a bioreactor for evaluating the response of colonies of geothermal organisms to changes in nutrient and environmental conditions. Data from initial experiments are presented and plans for future testing is discussed.

  19. Transport Functions Dominate the SAR11 Metaproteome at Low-Nutrient Extremes in the Sargasso Sea

    Sowell, Sarah M.; Wilhelm, Larry; Norbeck, Angela D.; Lipton, Mary S.; Nicora, Carrie D.; Barofsky, Douglas F.; carlson, Craig; Smith, Richard D.; Giovannoni, Stephen J.

    2009-01-01

    The northwestern Sargasso Sea is part of the North Atlantic subtropical oceanic gyre that is characterized as seasonally oligotrophic with pronounced stratification in the summer and autumn. Essentially a marine desert, the biological productivity of this region is reduced during stratified periods as a result of low concentrations of phosphorous and nitrogen in the euphotic zone. To better understand the mechanisms of microbial survival in this oligotrophic environment, we used capillary LC-tandem mass spectrometry to study the composition of microbial proteomes in surface samples collected in September 2005. A total of 2279 peptides that mapped to 236 SAR11 proteins, and 3208 peptides that mapped to 404 Synechococcus proteins, were detected. Mass spectra from SAR11 periplasmic binding proteins accounted for a disproportionately large fraction of the peptides detected, consistent with observations that these extremely small cells devote a large proportion of their volume to periplasm. Abundances were highest for periplasmic substrate-binding proteins for phosphate, amino acids, phosphonate, sugars, and spermidine. Although the data showed that a large fraction of microbial protein synthesis in the Sargasso Sea is devoted to inorganic and organic nutrient acquisition, the proteomes of both SAR11 and Synechococcus also indicated that these populations were actively growing. Our findings support the view that competition for multiple nutrients in oligotrophic systems is extreme but sufficient to sustain microbial community activity.

  20. Nutrient loading alters the performance of key nutrient exchange mutualisms.

    Shantz, Andrew A; Lemoine, Nathan P; Burkepile, Deron E

    2016-01-01

    Nutrient exchange mutualisms between phototrophs and heterotrophs, such as plants and mycorrhizal fungi or symbiotic algae and corals, underpin the functioning of many ecosystems. These relationships structure communities, promote biodiversity and help maintain food security. Nutrient loading may destabilise these mutualisms by altering the costs and benefits each partner incurs from interacting. Using meta-analyses, we show a near ubiquitous decoupling in mutualism performance across terrestrial and marine environments in which phototrophs benefit from enrichment at the expense of their heterotrophic partners. Importantly, heterotroph identity, their dependence on phototroph-derived C and the type of nutrient enrichment (e.g. nitrogen vs. phosphorus) mediated the responses of different mutualisms to enrichment. Nutrient-driven changes in mutualism performance may alter community organisation and ecosystem processes and increase costs of food production. Consequently, the decoupling of nutrient exchange mutualisms via alterations of the world's nitrogen and phosphorus cycles may represent an emerging threat of global change. PMID:26549314

  1. Mechanics

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  2. A Model of Chronic Nutrient Infusion in the Rat

    Fergusson, Grace; Ethier, Mélanie; Zarrouki, Bader; Fontés, Ghislaine; Poitout, Vincent

    2013-01-01

    Chronic exposure to excessive levels of nutrients is postulated to affect the function of several organs and tissues and to contribute to the development of the many complications associated with obesity and the metabolic syndrome, including type 2 diabetes. To study the mechanisms by which excessive levels of glucose and fatty acids affect the pancreatic beta-cell and the secretion of insulin, we have established a chronic nutrient infusion model in the rat. The procedure consists of cathete...

  3. Nutrient Needs of Young Athletes.

    Willenberg, Barbara; Hemmelgarn, Melinda

    1991-01-01

    Explains the nutritional requirements of children and adolescents, and the physiological roles of the major nutrients. Details the nutrient needs of young athletes, including pre- and postgame meals and fluid replacement. Discusses eating disorders and obesity. Advocates a diet rich in complex carbohydrates. (BC)

  4. Use of Select Nutrients to Foster Wellness.

    Cassel, Russell N.

    1987-01-01

    Discusses how to be healthy through one's diet. Lists 20 nutrients necessary for one's well being and explains role of each nutrient. Describes how nutrients complement one another and asserts that the right combination of nutrients can sometimes substitute for medication. Also lists 20 diagnostic categories of problems and suggests nutrients to…

  5. Nutrients, foods, and colorectal cancer prevention.

    Song, Mingyang; Garrett, Wendy S; Chan, Andrew T

    2015-05-01

    Diet has an important role in the development of colorectal cancer. In the past few decades, findings from extensive epidemiologic and experimental investigations have linked consumption of several foods and nutrients to the risk of colorectal neoplasia. Calcium, fiber, milk, and whole grains have been associated with a lower risk of colorectal cancer, and red meat and processed meat have been associated with an increased risk. There is substantial evidence for the potential chemopreventive effects of vitamin D, folate, fruits, and vegetables. Nutrients and foods also may interact, as a dietary pattern, to influence colorectal cancer risk. Diet likely influences colorectal carcinogenesis through several interacting mechanisms. These include the direct effects on immune responsiveness and inflammation, and the indirect effects of overnutrition and obesity-risk factors for colorectal cancer. Emerging evidence also implicates the gut microbiota as an important effector in the relationship between diet and cancer. Dietary modification therefore has the promise of reducing colorectal cancer incidence. PMID:25575572

  6. High speed data acquisition

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

  7. High speed data acquisition

    Cooper, P.S.

    1997-07-01

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab.

  8. FWS Approved Acquisition Boundaries

    US Fish and Wildlife Service, Department of the Interior — This data layer depicts the external boundaries of lands and waters that are approved for acquisition by the U.S. Fish and Wildlife Service (USFWS) in North...

  9. USB data acquisition solution

    Serges Lemo; Zhu June

    2007-01-01

    @@ 1 Introduction In recent years, USB has evolved from a simple, low-speed peripheral bus for mice, keyboards, and other computer accessories to the bus of choice for more demanding applications, including data acquisition (DAQ).

  10. Data acquisition at D0

    A large array of MicroVAX computers will be used for high-speed data acquisition and online filtering in the D0 experiment at Fermi National Accelerator Laboratory. We discuss new developments related to this system, in hardware and particularly in software. The new hardware includes multiported memory boards for faster and more direct input and output of event data. Most of the software development is related to the crucial role of the event filters, requiring an elaborate mechanism for control and monitoring of the FORTRAN based programs running in each of the MicroVAXes. (orig.)

  11. Recent Advances in Gut Nutrient Chemosensing

    Nguyen, C.A.; Akiba, Y.; Kaunitz, J.D.

    2016-01-01

    The field of gut nutrient chemosensing is evolving rapidly. Recent advances have uncovered the mechanism by which specific nutrient components evoke multiple metabolic responses. Deorphanization of G protein-coupled receptors (GPCRs) in the gut has helped identify previously unliganded receptors and their cognate ligands. In this review, we discuss nutrient receptors, their ligand preferences, and the evoked neurohormonal responses. Family A GPCRs includes receptor GPR93, which senses protein and proteolytic degradation products, and free fatty acid-sensing receptors. Short-chain free fatty acids are ligands for FFA2, previously GPR43, and FFA3, previously GPR41. FFA1, previously GPR40, is activated by long-chain fatty acids with GPR120 activated by medium- and long-chain fatty acids. The GPR119 agonist ethanolamide oleoylethanolamide (OEA) and bile acid GPR131 agonists have also been identified. Family C receptors ligand preferences include L-amino acids, carbohydrate, and tastants. The metabotropic glutamate receptor (mGluR), calcium-sensing receptor (CaR), and GPCR family C, group 6, subtype A receptor (GPRC6A) mediate L-amino acid-sensing. Taste receptors have a proposed role in intestinal chemosensing; sweet, bitter, and umami evoke responses in the gut via GPCRs. The mechanism of carbohydrate-sensing remains controversial: the heterodimeric taste receptor T1R2/T1R3 and sodium glucose cotransporter 1 (SGLT-1) expressed in L cells are the two leading candidates. Identification of specific nutrient receptors and their respective ligands can provide novel therapeutic targets for the treatment of diabetes, acid reflux, foregut mucosal injury, and obesity. PMID:22300073

  12. Open Source Software Acquisition

    Holck,, Jesper; Pedersen, Mogens Kühn; Larsen, Michael Holm

    2005-01-01

    Lately we have seen a growing interest from both public and private organisations to adopt Open Source Software (OSS), not only for a few, specific applications but also on a more general level throughout the organisation. As a consequence, the organisations’ decisions on adoption of OSS are becoming increasingly more important and complex. We present three perspectives organisations can employ in their decisions: seeing OSS acquisition as a business case, as COTS acquisition, and as architec...

  13. Measuring translation competence acquisition

    Orozco Jutorán, Mariana; Hurtado Albir, Amparo

    2002-01-01

    The following article describes the development of instruments for measuring the process of acquiring translation competence in written translation. Translation competence and its process of acquisition are firstly described, and then the lack of empirical research in our field is tackled. Thirdly, three measuring instruments especially developed to measure translation competence acquisition are presented: (i) to measure notions about translation, (ii) to measure students’ behaviour when face...

  14. Hindalco: The Novelis Acquisition

    S. R. Vishwanath

    2013-01-01

    The case documents a high profile cross border acquisition by an Indian company. In 2007, Hindalco, an Indian metals company, announced the acquisition of Novelis, a global leader in the production of aluminum rolled products with operations in four continents comprising 34 operating facilities in 11 countries. The key issue in the case is how to value a loss making enterprise with messy operations. Students are required to assess the strategic motives of the firms and perform a valuation ana...

  15. Mergers and Acquisitions

    Risberg, Annette

    , employee experiences and communication. Mergers and acquisitions remain one of the most common forms of growth, yet they present considerable challenges for the companies and management involved. The effects on stakeholders, including shareholders, managers and employees, must be considered as well as the...... broader implications for organizations. The book is structured clearly into sections concerned with the issues that arise before, during and after the mergers and acquisitions process including motives and planning, partner selection, integration, employee experiences and communication....

  16. Leaf mineral nutrient remobilization during leaf senescence and modulation by nutrient deficiency.

    Anne eMaillard

    2015-05-01

    Full Text Available Higher plants have to cope with fluctuating mineral resource availability. However strategies such as stimulation of root growth, increased transporter activities, and nutrient storage and remobilization have been mostly studied for only a few macronutrients. Leaves of cultivated crops (Zea mays, Brassica napus, Pisum sativum, Triticum aestivum, Hordeum vulgare and tree species (Quercus robur, Populus nigra, Alnus glutinosa grown under field conditions were harvested regularly during their life span and analysed to evaluate the net mobilization of 13 nutrients during leaf senescence. While N was remobilized in all plant species with different efficiencies ranging from 40% (maize to 90% (wheat, other macronutrients (K-P-S-Mg were mobilized in most species. Ca and Mn, usually considered as having low phloem mobility were remobilized from leaves in wheat and barley. Leaf content of Cu-Mo-Ni-B-Fe-Zn decreased in some species, as a result of remobilization. Overall, wheat, barley and oak appeared to be the most efficient at remobilization while poplar and maize were the least efficient. Further experiments were performed with rapeseed plants subjected to individual nutrient deficiencies. Compared to field conditions, remobilization from leaves was similar (N-S-Cu or increased by nutrient deficiency (K-P-Mg while nutrient deficiency had no effect on Mo-Zn-B-Ca-Mn, which seemed to be non-mobile during leaf senescence under field conditions. However, Ca and Mn were largely mobilized from roots (-97 and -86% of their initial root contents, respectively to shoots. Differences in remobilization between species and between nutrients are then discussed in relation to a range of putative mechanisms.

  17. Iron acquisition mechanisms of Flavobacterium psychrophilum

    Møller, Jeannette Dan; Ellis, A.E.; Barnes, A.C.; Dalsgaard, Inger

    2005-01-01

    Forty strains of Flavobacterium psychrophilum were tested for the production of siderophores using the universal Chrome Azurol S (CAS) assay. The majority of the strains (85%) were CAS positive (CAS+) and some (15%) were CAS negative (CAS-). The cryptic plasmid pCP1 was carried by all positive...

  18. Nutrient and Coliform Loading (NCL)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a database of available fecal coliform bacteria, fecal streptococci bacteria, and nutrient loading data. Loading for contaminants other than fecal coliform...

  19. Nutrient imbalance in Norway spruce

    Thelin, Gunnar

    2000-11-01

    The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

  20. Nutrient imbalance in Norway spruce

    The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

  1. Innovations in Defense Acquisition: Asymmetric Information and Incentive Contract Design

    Peter Coughlan; Gates, William

    2010-01-01

    Sponsored Report (for Acquisition Research Program) This report continues a research stream initiated in 2007 to apply mechanism design concepts to the DoD''s acquisition transactions. Recognizing the central importance of private information and incentives, mechanism design reflects the decisions made by individuals and institutions based on the information they possess and the incentives they face. The designer chooses the mechanism (institutional structure) that promotes the desired o...

  2. Mechanics

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  3. Post-Acquisition IT Integration

    Henningsson, Stefan; Yetton, Philip

    2013-01-01

    The extant research on post-acquisition IT integration analyzes how acquirers realize IT-based value in individual acquisitions. However, serial acquirers make 60% of acquisitions. These acquisitions are not isolated events, but are components in growth-by-acquisition programs. To explain how...... serial acquirers realize IT-based value, we develop three propositions on the sequential effects on post-acquisition IT integration in acquisition programs. Their combined explanation is that serial acquirers must have a growth-by-acquisition strategy that includes the capability to improve IT...... integration capabilities, to sustain high alignment across acquisitions and to maintain a scalable IT infrastructure with a flat or decreasing cost structure. We begin the process of validating the three propositions by investigating a longitudinal case study of a growth-by-acquisition program....

  4. Sugar Cane Nutrient Distribution Analysis

    Neutron Activation Analysis (NAA), Molecular Absorption Spectrometry (UV-Vis), and Flame Photometry techniques were applied to measure plant nutrient concentrations of Br, Ca, Cl, K, Mn, N, Na and P in sugar-cane root, stalk and leaves. These data will be used to explore the behavior of element concentration in different parts of the sugar-cane to better understand the plant nutrient distribution during its development.

  5. Acquisition of Romance languages. Introduction

    Gavarró, Anna; Lleó, Conxita

    2006-01-01

    Generative grammar addressed for the first time acquisition as a central issue in the study of grammar. This perspective has given rise over the years to a considerable body of work, mainly on first language acquisition, but also on second language acquistion, bilingual acquisition, and the acquisition by children affected by SLI. If we assume continuity, i.e. that all stages in acquisition reflect possible natural languages, we must posit a mutual dependency between grammatical theory and th...

  6. Seismic data acquisition systems

    Details of seismic data acquisition systems developed at the Bhabha Atomic Research Centre, Bombay are reported. The seismic signals acquired belong to different signal bandwidths in the band from 0.02 Hz to 250 Hz. All these acquisition systems are built around a unique technique of recording multichannel data on to a single track of an audio tape and in digital form. Techniques of how these signals in different bands of frequencies were acquired and recorded are described. Method of detecting seismic signals and its performance is also discussed. Seismic signals acquired in different set-ups are illustrated. Time indexing systems for different set-ups and multichannel waveform display systems which form essential part of the data acquisition systems are also discussed. (author). 13 refs., 6 figs., 1 tab

  7. VERITAS Data Acquisition

    Hays, E

    2007-01-01

    VERITAS employs a multi-stage data acquisition chain that extends from the VME readout of custom 500 MS/s flash ADC electronics to the construction of telescope events and ultimately the compilation of information from each telescope into array level data. These systems provide access to the programming of the channel level triggers and the FADCs. They also ensure the proper synchronization of event information across the array and provide the first level of data quality monitoring. Additionally, the data acquisition includes features to handle the readout of special trigger types and to monitor channel scaler rates. In this paper we describe the software and hardware components of the systems and the protocols used to communicate between the VME, telescope, and array levels. We also discuss the performance of the data acquisition for array operations.

  8. Modeling the Distinct Phases of Skill Acquisition

    Tenison, Caitlin; Anderson, John R.

    2016-01-01

    A focus of early mathematics education is to build fluency through practice. Several models of skill acquisition have sought to explain the increase in fluency because of practice by modeling both the learning mechanisms driving this speedup and the changes in cognitive processes involved in executing the skill (such as transitioning from…

  9. Present Status and Future Development of HL-2A Data Acquisition System

    CHENLiaoyuan; LUOCuiwen; PANLi; YANGYang; XUZhengyu; HANQian

    2002-01-01

    HL-2A data acquisition system (DAS) was developed and used in engineering tests last year. The main parts of the system include the experiment network, the data acquisition and processing mechanisms, and the graph and character display equipments.

  10. Optimizing Nutrient Uptake in Biological Transport Networks

    Ronellenfitsch, Henrik; Katifori, Eleni

    2013-03-01

    Many biological systems employ complex networks of vascular tubes to facilitate transport of solute nutrients, examples include the vascular system of plants (phloem), some fungi, and the slime-mold Physarum. It is believed that such networks are optimized through evolution for carrying out their designated task. We propose a set of hydrodynamic governing equations for solute transport in a complex network, and obtain the optimal network architecture for various classes of optimizing functionals. We finally discuss the topological properties and statistical mechanics of the resulting complex networks, and examine correspondence of the obtained networks to those found in actual biological systems.

  11. Data acquisition system enhancements

    The principal data acquisition system consists of a DEC PDP 11/60 computer with two 5 megabyte RL-01 disks, a 1600 bpi 75 ips 9 track tape drive, a Printronix P-300 printer/plotter with a Trilog Tektronix hardcopy board, a DEC VT-11 graphics display, a Tektronix 4006 terminal and a BiRa MBD-11 controlling a CAMAC crate to connect with twelve Tracor Northern TN-1213 ADCs. 15 NPL-built 75 MHz scalers are read via an IEEE-488 bus interface. New data acquisition hardware and software are described and some programming considerations are discussed

  12. LEGS data acquisition facility

    The data acquisition facility for the LEGS medium energy photonuclear beam line is composed of an auxiliary crate controller (ACC) acting as a front-end processor, loosely coupled to a time-sharing host computer based on a UNIX-like environment. The ACC services all real-time demands in the CAMAC crate: it responds to LAMs generated by data acquisition modules, to keyboard commands, and it refreshes the graphics display at frequent intervals. The host processor is needed only for printing histograms and recording event buffers on magnetic tape. The host also provides the environment for software development. The CAMAC crate is interfaced by a VERSAbus CAMAC branch driver

  13. Nutrient availability regulates cell cycle through a Pho85 CDK-dependent control of Cln3 cyclin stability

    Menoyo Molins, Alexandra

    2012-01-01

    Cell cycle control by trophic factors has a key role in regulation of cell proliferation in all organisms. Nutrients are one of these important factors needed by cells to reproduce, so very well regulated mechanisms must exist that connect nutrient availability to cell cycle. Hence the importance on studying how exactly nutrient-dependent signaling pathways work. Cln3, the most upstream G1 cyclin in Saccharomyces cerevisiae, is one well demonstrated common effector of multiple nutrient-dep...

  14. The Effects of Foreign Language Motivation in Second Language Acquisition

    WU Miao-ru

    2013-01-01

    Foreign language motivation is regarded as one source of individual differences in second language acquisition. Learn-ing motivation is a dynamic mechanism which gives rise to learning activities. Learners ’motivation is a decisive factor for the suc-cess of second language acquisition.

  15. Cycling and loss of nutrients in pastures

    Pastures are fundamentally different than croplands. When cropland is harvested, large amounts of plant nutrients are removed so relatively large rates of nutrients are often needed. In pasture, most of the nutrients harvested by livestock are returned. The proportion of nutrients returned by livest...

  16. MPS Data Acquisition System

    A description is given of the data acquisition system used with the multiparticle spectrometer facility at Brookhaven. Detailed information is provided on that part of the system which connects the detectors to the data handler; namely, the detector electronics, device controller, and device port optical isolator

  17. Acquisition IT Integration

    Henningsson, Stefan; Øhrgaard, Christian

    2015-01-01

    the acquirers appropriate the use of agency workers as part of its acquisition strategy. For the investigated acquirers, assigning roles to agency workers is contingent on balancing the needs of knowledge induction and knowledge retention, as well as experience richness and in-depth under-standing. Composition...

  18. Competencies: requirements and acquisition

    Kuenn, A.C.; Meng, C.M.; Peters, Z.; Verhagen, A.M.C.

    2013-01-01

    Higher education is given the key task to prepare the highly talented among the young to fulfil highly qualified roles in the labour market. Successful labour market performance of graduates is generally associated with the acquisition of the correct competencies. Education as an individual investme

  19. Acquisitions List No. 42.

    Planned Parenthood--World Population, New York, NY. Katherine Dexter McCormick Library.

    The "Acquisitions List" of demographic books and articles is issued every two months by the Katharine Dexter McCormick Library. Divided into two parts, the first contains a list of books most recently acquired by the Library, each one annotated and also marked with the Library call number. The second part consists of a list of annotated articles,…

  20. Acquisitions List No. 43.

    Planned Parenthood--World Population, New York, NY. Katherine Dexter McCormick Library.

    The "Acquisitions List" of demographic books and articles is issued every two months by the Katharine Dexter McCormick Library. Divided into two parts, the first contains a list of books most recently acquired by the Library, each one annotated and also marked with the Library call number. The second part consists of a list of annotated articles,…

  1. Assessing nutrient cycling in the soil/plant/animal system of semi-arid pasture lands

    Isotopic labelling is helpful in understanding the fate of nutrient fertilizers and determining the chemical and biochemical mechanisms that affect nutrient cycling through the soil/plant/animal system. Use of isotopic P and S in grassland systems is briefly discussed. Plant growth is discussed in response to nutrient levels in soil extracts and plant tissue. Optimizing plant growth will generally ensure high yields of quality forage that will result in good animal performance. (author)

  2. Mammary blood flow and nutrient uptake

    Farmer, Chantal; Trottier, N.L.; Dourmad, Jean-Yves

    2015-01-01

    Sow milk is the major source of nutrients for suckling piglets and taking into account the large litter sizes of our current sow genotypes, it is imperative to maximize nutrient use by the mammary gland. The amount of nutrients available to mammary tissue is dependent upon the concentrations of nutrients in blood and the rate of its flow to the lactating glands. Nutrient availability to the udder may be estimated by measuring mammary arteriovenous differences, and mammary blood flow can be me...

  3. A System for Managing Replenishment of a Nutrient Solution Using an Electrical Conductivity Controller

    Davis, D.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.

    1998-01-01

    Control of nutrient solution parameters is very important for the growth and development of plants grown hydroponically. Protocols involving different nutrient solution replenishment times (e.g. one-week, two-week, or two-day replenishment) provide manual periodic control of the nutrient solution's electrical conductivity (EC). Since plants take-up nutrients as they grow, manual control has a drawback in that EC is not held constant between replenishments. In an effort to correct this problem the Center for Food and Environmental Systems for Human Exploration of Space at Tuskegee University has developed a system for managing and controlling levels of EC over a plant's entire growing cycle. A prototype system is being tested on sweetpotato production using the nutrient film technique (NFT), and it is being compared to a system in which sweetpotatoes are grown using NFT with manual control. NASA has played an important role in the development of environmental control systems. They have become a forerunner in growing plants hydroponically with some control systems through the use of networked data acquisition and control using environmental growth chambers. Data acquisition systems which involve the use of real-time, calibration, set points, user panel, and graphical representation programming provide a good method of controlling nutrient solution parameters such as EC and pH [Bledsoe, 19931]. In NASA's Biomass Production Chamber (BPC) at Kennedy Space Center, control is provided by a programmable logic controller (PLC). This is an industrial controller which combines ladder computer logic which has the ability to handle various levels of electrical power. The controller controls temperature, light and other parameters that affect the plant's environment, in the BPC, the Nutrient Delivery System (NIX), a sub-system of the PLC, controls nutrient solution parameters such as EC, pH, and solution levels. When the nutrient EC measurement goes outside a preset range (120

  4. Sample Acquisition Techniques for Exobiology Flight Experiments

    Kojiro, Daniel R.; Carle, Glenn C.; Stratton, David M.; Valentin, Jose R.; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    Exobiology Flight Experiments involve complex analyses conducted in environments far different than those encountered in terrestrial applications. A major part of the analytical challenge is often the selection, acquisition, delivery and, in some cases, processing of a sample suitable for the analytical requirements of the mission. The added complications of severely limited resources and sometimes rigid time constraints combine to make sample acquisition potentially a major obstacle for successful analyses. Potential samples come in a wide range including planetary atmospheric gas and aerosols (from a wide variety of pressures), planetary soil or rocks, dust and ice particles streaming off of a comet, and cemetery surface ice and rocks. Methods to collect and process sample are often mission specific, requiring continual development of innovative concepts and mechanisms. These methods must also maintain the integrity of the sample for the experimental results to be meaningful. We present here sample acquisition systems employed from past missions and proposed for future missions.

  5. ROLES OF DOPAMINE D1 AND D2 RECEPTORS IN THE ACQUISITION AND EXPRESSION OF FAT-CONDITIONED FLAVOR PREFERENCES IN RATS

    Cruz, J.A.D. Dela; Icaza-Cukali, D.; Taybali, H.; Sampson, C.; Galanopoulos, V.; Bamshad, D.; Touzani, K.; Sclafani, A.; Bodnar, R.J.

    2012-01-01

    Sugars and fats elicit innate and learned flavor preferences with the latter mediated by flavor-flavor (orosensory) and flavor-nutrient (post-ingestive) processes. Systemic dopamine (DA) D1 (SCH23390: SCH) and D2 (raclopride: RAC), but not opioid antagonists blocked the acquisition and expression of flavor-flavor preferences conditioned by sugars. In addition, systemic D1, but not D2 or opioid antagonists blocked the acquisition of flavor-nutrient preferences conditioned by intragastric (IG) ...

  6. Enhancement of spilled oil biodegradation by nutrients of natural origin

    Ten years ago, Elf Aquitaine began developing the technologies for the acceleration of hydrocarbon biodegradation. The continuation of this work has involved the study of new additives to complement the oleophilic nutrient, INIPOL EAP 22. In particular, it has been shown in both laboratory and in situ tests that hydrocarbon degradation can be accelerated by animal meals, which are natural products. Preliminary laboratory studies carried out under batch conditions have shown that the use of these products has resulted in considerable growth of the bacteria, coupled with a notable increase in the biological degradation kinetics of the hydrocarbons. These results are comparable with the performance of the nutrient INIPOL EAP 22. In situ experiments undertaken on soils polluted by hydrocarbons have shown that by using animal meals, 50 percent biodegradation was obtained after six weeks and this increased to 80 percent when mechanical aeration was also employed. Under nutrient-free control conditions, 25 percent biodegradation was obtained with no aeration and 35 percent with mechanical aeration. In trials using coastal sandy sediments, the use of these nutrients has resulted in an increase of both the number of hydrocarbon specific bacteria and the hydrocarbon degradation. It can be concluded from these pilot experiments that in the development of bioremediation as an operational tool in the response to accidental oil spills, these nutrients of natural origin represent an interesting advance

  7. RF merger and acquisition market

    Evgeniya V. Vidishcheva

    2011-04-01

    Full Text Available The article gives brief characteristic of merger and acquisition market situation in Russia, brings in overview of bargains in 2009–2010. Russian merger and acquisition market is in early stage of development.

  8. RF merger and acquisition market

    Evgeniya V. Vidishcheva; Merab S. Sichinava; Marina V. Kogan

    2011-01-01

    The article gives brief characteristic of merger and acquisition market situation in Russia, brings in overview of bargains in 2009–2010. Russian merger and acquisition market is in early stage of development.

  9. Data acquisition instruments: Psychopharmacology

    Hartley, D.S. III

    1998-01-01

    This report contains the results of a Direct Assistance Project performed by Lockheed Martin Energy Systems, Inc., for Dr. K. O. Jobson. The purpose of the project was to perform preliminary analysis of the data acquisition instruments used in the field of psychiatry, with the goal of identifying commonalities of data and strategies for handling and using the data in the most advantageous fashion. Data acquisition instruments from 12 sources were provided by Dr. Jobson. Several commonalities were identified and a potentially useful data strategy is reported here. Analysis of the information collected for utility in performing diagnoses is recommended. In addition, further work is recommended to refine the commonalities into a directly useful computer systems structure.

  10. Amplitudes, acquisition and imaging

    Bloor, Robert

    1998-12-31

    Accurate seismic amplitude information is important for the successful evaluation of many prospects and the importance of such amplitude information is increasing with the advent of time lapse seismic techniques. It is now widely accepted that the proper treatment of amplitudes requires seismic imaging in the form of either time or depth migration. A key factor in seismic imaging is the spatial sampling of the data and its relationship to the imaging algorithms. This presentation demonstrates that acquisition caused spatial sampling irregularity can affect the seismic imaging and perturb amplitudes. Equalization helps to balance the amplitudes, and the dealing strategy improves the imaging further when there are azimuth variations. Equalization and dealiasing can also help with the acquisition irregularities caused by shot and receiver dislocation or missing traces. 2 refs., 2 figs.

  11. Unsupervised Language Acquisition

    De Marcken, C

    1996-01-01

    This thesis presents a computational theory of unsupervised language acquisition, precisely defining procedures for learning language from ordinary spoken or written utterances, with no explicit help from a teacher. The theory is based heavily on concepts borrowed from machine learning and statistical estimation. In particular, learning takes place by fitting a stochastic, generative model of language to the evidence. Much of the thesis is devoted to explaining conditions that must hold for this general learning strategy to arrive at linguistically desirable grammars. The thesis introduces a variety of technical innovations, among them a common representation for evidence and grammars, and a learning strategy that separates the ``content'' of linguistic parameters from their representation. Algorithms based on it suffer from few of the search problems that have plagued other computational approaches to language acquisition. The theory has been tested on problems of learning vocabularies and grammars from unse...

  12. Icy Soil Acquisition Device for the 2007 Phoenix Mars Lander

    Chu, Philip; Wilson, Jack; Davis, Kiel; Shiraishi, Lori; Burke, Kevin

    2008-01-01

    The Icy Soil Acquisition Device is a first of its kind mechanism that is designed to acquire ice-bearing soil from the surface of the Martian polar region and transfer the samples to analytical instruments, playing a critical role in the potential discovery of existing water on Mars. The device incorporates a number of novel features that further the state of the art in spacecraft design for harsh environments, sample acquisition and handling, and high-speed low torque mechanism design.

  13. Multiprocessor data acquisition system

    A multiprocessor data acquisition system has been built to replace the single processor systems at the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory. The multiprocessor system was needed to accommodate the higher data rates at IPNS brought about by improvements in the source and changes in instrument configurations. This paper describes the hardware configuration of the system and the method of task sharing and compares results to the single processor system

  14. Implementing acquisition strategies

    The objective of this paper is to address some of the strategies necessary to effect a successful asset or corporate acquisition. Understanding the corporate objective, the full potential of the asset, the specific strategies to be employed, the value of time, and most importantly the interaction of all these are crucial, for missed steps are likely to result in missed opportunities. The amount of factual information that can be obtained and utilized in a timely fashion is the largest single hurdle to the capture of value in the asset or corporate acquisition. Fact, familiarity and experience are key in this context. The importance of the due diligence process prior to title or data transfer cannot be overemphasized. Some of the most important assets acquired in a merger may be the people. To maximize effectiveness, it is essential to merge both existing staff and those that came with the new acquisition as soon as possible. By thinking together as a unit, knowledge and experience can be applied to realize the potential of the asset. Hence team building is one of the challenges, doing it quickly is usually the most effective. Developing new directions for the new enlarged company by combining the strengths of the old and the new creates more value, as well as a more efficient operation. Equally important to maximizing the potential of the new acquisition is the maintenance of the momentum generated by the need to grow that gave the impetus to acquiring new assets in the first place. In brief, the right mix of vision, facts and perceptions, quick enactment of the post-close strategies and keeping the momentum alive, are the principal ingredients of a focused strategy

  15. Competencies: requirements and acquisition

    Kuenn, A.C.; Meng, C.M.; Peters, Z.; Verhagen, A.M.C.

    2013-01-01

    Higher education is given the key task to prepare the highly talented among the young to fulfil highly qualified roles in the labour market. Successful labour market performance of graduates is generally associated with the acquisition of the correct competencies. Education as an individual investment in human capital is a viewpoint dating back to the 17th century and the writings of Sir William Petty (1662), and includes later work by Adam Smith (1776). The idea was formalized and brought in...

  16. Advanced Data Acquisition Systems

    Perotti, J.

    2003-01-01

    Current and future requirements of the aerospace sensors and transducers field make it necessary for the design and development of new data acquisition devices and instrumentation systems. New designs are sought to incorporate self-health, self-calibrating, self-repair capabilities, allowing greater measurement reliability and extended calibration cycles. With the addition of power management schemes, state-of-the-art data acquisition systems allow data to be processed and presented to the users with increased efficiency and accuracy. The design architecture presented in this paper displays an innovative approach to data acquisition systems. The design incorporates: electronic health self-check, device/system self-calibration, electronics and function self-repair, failure detection and prediction, and power management (reduced power consumption). These requirements are driven by the aerospace industry need to reduce operations and maintenance costs, to accelerate processing time and to provide reliable hardware with minimum costs. The project's design architecture incorporates some commercially available components identified during the market research investigation like: Field Programmable Gate Arrays (FPGA) Programmable Analog Integrated Circuits (PAC IC) and Field Programmable Analog Arrays (FPAA); Digital Signal Processing (DSP) electronic/system control and investigation of specific characteristics found in technologies like: Electronic Component Mean Time Between Failure (MTBF); and Radiation Hardened Component Availability. There are three main sections discussed in the design architecture presented in this document. They are the following: (a) Analog Signal Module Section, (b) Digital Signal/Control Module Section and (c) Power Management Module Section. These sections are discussed in detail in the following pages. This approach to data acquisition systems has resulted in the assignment of patent rights to Kennedy Space Center under U.S. patent # 6

  17. Competencies: requirements and acquisition

    Meng C.M.; Peters Z.; Verhagen A.M.C.; Künn-Nelen A.C.

    2013-01-01

    Higher education is given the key task to prepare the highly talented among the young to fulfil highly qualified roles in the labour market. Successful labour market performance of graduates is generally associated with the acquisition of the correct competencies. Education as an individual investment in human capital is a viewpoint dating back to the 17th century and the writings of Sir William Petty 1662, and includes later work by Adam Smith 1776. The idea was formalized and brought into m...

  18. Data Acquisition System

    The Data Acquisition System (DAS) is comprised of a Hewlett-Packard (HP) model 9816, Series 200 Computer System with the appropriate software to acquire, control, and archive data from a Data Acquisition/Control Unit, models HP3497A and HP3498A. The primary storage medium is an HP9153 16-megabyte hard disc. The data is backed-up on three floppy discs. One floppy disc drive is contained in the HP9153 chassis; the other two comprise an HP9122 dual disc drive. An HP82906A line printer supplies hard copy backup. A block diagram of the hardware setup is shown. The HP3497A/3498A Data Acquisition/Control Units read each input channel and transmit the raw voltage reading to the HP9816 CPU via the HPIB bus. The HP9816 converts this voltage to the appropriate engineering units using the calibration curves for the sensor being read. The HP9816 archives both the raw and processed data along with the time and the readings were taken to hard and floppy discs. The processed values and reading time are printed on the line printer. This system is designed to accommodate several types of sensors; each type is discussed in the following sections

  19. MDSplus data acquisition system

    MDSplus, a tree based, distributed data acquisition system, was developed in collaboration with the ZTH Group at Los Alamos National Lab and the RFX Group at CNR in Padua, Italy. It is currently in use at MIT, RFX in Padua, TCV at EPFL in Lausanne, and KBSI in South Korea. MDSplus is made up of a set of X/motif based tools for data acquisition and display, as well as diagnostic configuration and management. It is based on a hierarchical experiment description which completely describes the data acquisition and analysis tasks and contains the results from these operations. These tools were designed to operate in a distributed, client/server environment with multiple concurrent readers and writers to the data store. While usually used over a Local Area Network, these tools can be used over the Internet to provide access for remote diagnosticians and even machine operators. An interface to a relational database is provided for storage and management of processed data. IDL is used as the primary data analysis and visualization tool. IDL is a registered trademark of Research Systems Inc. copyright 1996 American Institute of Physics

  20. Conjoined Constraints and Phonological Acquisition

    Bonilha, Giovana

    2003-01-01

    Since the start of Optimality Theory (Prince & Smolensky, 1993), research on phonological acquisition has explored the explanatory potential of constraint theories. This study, also based on Optimality Theory, attempts to analyze the acquisition of CVVC syllable structure by Brazilian Portuguese children and addresses the issue of Local Conjunction (Smolensky, 1995, 1997) in research that deals with problems of phonological acquisition.

  1. First Language Acquisition and Teaching

    Cruz-Ferreira, Madalena

    2011-01-01

    "First language acquisition" commonly means the acquisition of a single language in childhood, regardless of the number of languages in a child's natural environment. Language acquisition is variously viewed as predetermined, wondrous, a source of concern, and as developing through formal processes. "First language teaching" concerns schooling in…

  2. 营养物质刺激肠道L细胞分泌GLP-1的机制%The mechanisms of nutrient-stimulated GLP-1 secretion from intestinal L-cells

    王晓兢; 武晓泓

    2011-01-01

    在营养物质的刺激作用下,肠上皮的L细胞分泌胰高血糖素样肽-1( GLP-1),后者具有控制餐后血糖和食欲的重要作用.这些营养物质包括糖类物质、蛋白质、脂类物质,其中糖类物质刺激L细胞分泌GLP-1的机制包括ATP敏感的K通道(KATP通道)、钠-葡萄糖协同转运体(SGLT)1、味觉受体通路;蛋白质刺激L细胞分泌GLP-1的机制可能为电压门控的Ca2通道、Na+ -K+-2CI -同向转运体、促离子型γ-氨基丁酸(GABA)受体、Na+耦联转运体所致的细胞膜去极化;脂类物质刺激L细胞分泌GILP-1的机制可能与脂肪酸敏感的G蛋白耦联受体(GRPs)有关.%In response to the stimulation of nutrients,glucagon-like peptide-1 (GLP-1) is secreted from the intestinal epithelial L-cells,which is important to postprandial plasma glucagon modulation and appetite control.The nutrients include carbohydrates,proteins and lipids.Carbohydrates stimulate GLP-1 release from L-cells by ATP-sensitive K+ channel( KATP channel),sodium-glucose cotransporter(SGLT) 1 and taste receptor pathways.Proteins stimulate GLP-1 release from L-cells by plasma membrane depolarization which is initiated by voltage gated Ca2 + -channels,Na+ -K + -2Cl - cotransporters,ionotropic GABA receptor and Na + -coupled transporters,while lipids stimulate GLP-1 release from L-cells by fatty acids-sensitive G-protein coupled receptors.

  3. Hunting Nutrients and Trapping Carbon

    Soil fertility is enhanced directly by arbuscular mycorrhizal fungi (AMF) efficiently absorbing the maximum amount of nutrients available and indirectly by formation of stabilized soil aggregates. Glomalin is sticky, not easily soluble substance, on AMF hyphae and provides a protective coating to b...

  4. Regulating nutrient allocation in plants

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  5. Nutrients for the aging eye

    Rasmussen HM

    2013-06-01

    Full Text Available Helen M Rasmussen,1 Elizabeth J Johnson2 1Educational Studies, Lesley University, Cambridge, MA, USA; 2Carotenoid and Health Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA Abstract: The incidence of age-related eye diseases is expected to rise with the aging of the population. Oxidation and inflammation are implicated in the etiology of these diseases. There is evidence that dietary antioxidants and anti-inflammatories may provide benefit in decreasing the risk of age-related eye disease. Nutrients of interest are vitamins C and E, β-carotene, zinc, lutein, zeaxanthin, and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. While a recent survey finds that among the baby boomers (45–65 years old, vision is the most important of the five senses, well over half of those surveyed were not aware of the important nutrients that play a key role in eye health. This is evident from a national survey that finds that intake of these key nutrients from dietary sources is below the recommendations or guidelines. Therefore, it is important to educate this population and to create an awareness of the nutrients and foods of particular interest in the prevention of age-related eye disease. Keywords: nutrition, aging, eye health

  6. Rhizosphere priming: a nutrient perspective

    Rhizosphere priming is the change in decomposition of soil organic matter (SOM) caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C) dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizospher...

  7. Impoverishment of Soil Nutrients in Gully Erosion Areas in Yuanmou Basin

    Zhang Jian-guo; Li Hui-xia; He Xiao-rong; Sheng Xin-ju; Fan Jian-rong; Zhu Bo

    2003-01-01

    The impoverishment of soil nutrients of nine gully head areas in Yuanmou Basin is assessed through an integrated evaluation method established on the basis of Fuzzy mathematics and multivariate mathematical theory. Results show that soil erosion of gully erosion area in Yuanmou basin has resulted in severe impoverishment of soil nutrients. All gully head areas are at high leves of impoverishment except for one at middle. By probing into and analyzing the mechanism of impoverishment of soil nutrients, we find that soil erosion has led to impoverishment of soil nutrients in a way of compacting soil, heightening position of obstacle horizon, and reducing the content of organic matter, as well as the direct loss of nutrient elements. Finally, this paper points out that soil and water conservation arming at the prevention of soil erosion is the most effective way against impoverishment of soil nutrients in Yuanmou basin.

  8. Digestate management in Flanders: nutrient removal versus nutrient recovery

    Lebuf, Viooltje; Vanelsacker, Sara; Accoe, Frederik; Vaneeckhaute, Céline; Meers, Erik; Michels, Evi

    2013-01-01

    Intensive livestock production combined with limited availability of land for manure disposal and fertilisation restrictions by the EU-legislation make Flanders (Belgium) a 100% Nitrate Vulnerable Zone. The Flemish Manure Decree has been implemented in order to take measures against nitrate and phosphate pollution in water, resulting from the produced nutrient excess. From the 39 anaerobic digestion plants operational in Flanders, most of the installations are co-digestion plants that proc...

  9. Data acquisition system DAPHNE

    DAPHNE is a data acquisition system which is being created to satisfy the needs of the accelerator based experimental research program of the division in particular the one at ATLAS. It is CAMAC based with a hardware front end consisting of multiple single board processors in a Multibus cage to provide a parallel processing capability. The host computer, a VAX 750, will provide for data logging, histogram memory space, and user interaction. The first DAPHNE system is being designed and constructed for use by ATLAS and is expected to be ready by late spring, 1985

  10. Early object rule acquisition.

    Pierce, D E

    1991-05-01

    The purpose of this study was to generate a grounded theory of early object rule acquisition. The grounded theory approach and computer coding were used to analyze videotaped samples of an infant's and a toddler's independent object play, which produced the categories descriptive of three primary types of object rules; rules of object properties, rules of object action, and rules of object affect. This occupational science theory offers potential for understanding the role of objects in human occupations, for development of instruments, and for applications in occupational therapy early intervention. PMID:2048625

  11. Nutrient management for rice production

    The nutrient removed by the crops far exceeds the amounts replenished through fertilizer, causing a much greater strain on the native soil reserves. The situation is further aggravated in countries like India, where sub-optimal fertilizer used by the farmers is a common phenomenon rather than an exception. The total consumption of nutrients of all crops in India, even though reached 15 million tons in 1997, remains much below the estimated nutrient removal of 25 million tons (Swarup and Goneshamurthy, 1998). The gap between nutrient removal supplied through fertilizer has widened further in 2000 to 34 million tons of plant nutrients from the soil against an estimated fertilizer availability of 18 million tons (Singh and Dwivedi, 1996). Nitrogen is the nutrient which limits the most the rice production worldwide. In Asia, where more than 90 percent of the world's rice is produced, about 60 percent of the N fertilizer consumed is used on rice (Stangel and De Dutta, 1985). Conjunctive use of organic material along with fertilizer has been proved an efficient source of nitrogen. Organic residue recycling is becoming an increasingly important aspect of environmentally sound sustainable agriculture. Returning residues like green manure to the soil is necessary for maintaining soil organic matter, which is important for favourable soil structure, soil water retention and soil microbial flora and fauna activities. Use of organic manures in conjunction or as an alternative to chemical fertilizer is receiving attention. Green manure, addition to some extent, helps not only in enhancing the yield but also in improving the physical and chemical nature of soils. The excessive application of chemical fertilizers made it imperative that a part of inorganic fertilizer may be substituted with the recycling of organic wastes. Organic manure has been recorded to enhance the efficiency and reduce the requirement of chemical fertilizers. Partial nitrogen substitution through organic

  12. Business valuation and pricing in merger and acquisition context : case study: Intel - Altera

    Nguyen Tuan, Viet

    2015-01-01

    Merger and acquisition play an important role in business landscape, and are often considered as mechanisms of a market economy to become more efficient and effective. A typical merger or acquisition deal is, however, a very timeconsuming, complicated process with many phases, involving many parties and built on a very complex structure. Proper valuation is one of the crucial keys to the success of every merger or acquisition deal. This thesis discusses merger and acquisition and introduce...

  13. Zinc: an essential but elusive nutrient123

    Janet C. King

    2011-01-01

    Zinc is essential for multiple aspects of metabolism. Physiologic signs of zinc depletion are linked with diverse biochemical functions rather than with a specific function, which makes it difficult to identify biomarkers of zinc nutrition. Nutrients, such as zinc, that are required for general metabolism are called type 2 nutrients. Protein and magnesium are examples of other type 2 nutrients. Type 1 nutrients are required for one or more specific functions: examples include iron, vitamin A,...

  14. Nutrient quality of fast food kids meals

    Exposure of children to kids’ meals at fast food restaurants is high; however, the nutrient quality of such meals has not been systematically assessed. We assessed the nutrient quality of fast food meals marketed to young children, i.e., "kids meals". The nutrient quality of kids’ meals was assessed...

  15. Portable data acquisition system

    Lawrence Livermore National Laboratory (LLNL) has developed a Portable Data Acquisition (DAQ) System that is basically a laboratory-scale of Program Logic Control (PLC). This DAQ system can obtain signals from numerous sensors (e.g., pH, level, pressure, flow meters), open and close valves, and turn on and off pumps. The data can then be saved on a spreadsheet or displayed as a graph/indicator in real-time on a computer screen. The whole DAQ system was designed to be portable so that it could sit on a bench top during laboratory-scale treatability studies, or moved out into the field during larger studies. This DAQ system is also fairly simple to use. All that is required is some working knowledge of LabVIEW 4.1, and how to properly wire the process equipment. The DAQ system has been used during treatability studies on cesium precipitation, controlled hydrolysis of water- reactive wastes, and other waste treatment studies that enable LLNL to comply with the Federal Facility Compliance Act (FFCAct). Improved data acquisition allows the study to be better monitored, and therefore better controlled, and can be used to determine the results of the treatment study more effectively. This also contributes to the design of larger treatment processes

  16. Aircraft Data Acquisition

    Elena BALMUS

    2016-03-01

    Full Text Available The introduction of digital systems instead of analog ones has created a major separation in the aviation technology. Although the digital equipment made possible that the increasingly faster controllers take over, we should say that the real world remains essentially analogue [4]. Fly-by-wire designers attempting to control and measure the real feedback of an aircraft were forced to find a way to connect the analogue environment to their digital equipment. In order to manage the implications of this division in aviation, data optimization and comparison has been quite an important task. The interest in using data acquisition boards is being driven by the technology and design standards in the new generation of aircraft and the ongoing efforts of reducing weight and, in some cases addressing the safety risks. This paper presents a sum of technical report data from post processing and diversification of data acquisition from Arinc 429 interface on a research aircraft platform. Arinc 429 is by far the most common data bus in use on civil transport aircraft, regional jets and executive business jets today. Since its introduction on the Boeing 757/767 and Airbus aircraft in the early 1980s hardly any aircraft has been produced without the use of this data bus. It was used widely by the air transport indu

  17. Nutrient needs of performance horses

    Laurie Lawrence

    2008-01-01

    In 1989, the National Research Council (NRC) Subcommittee on Horse Nutrition defined three categories of exercise: light, moderate or intense. In the 6th revised edition of "The Nutrient Requirements of Horses" (NRC, 2007), there are four categories for exercising horses: light exercise, moderate exercise, heavy exercise and very heavy exercise. Light exercise is described as 1 to 3 hours/week of mostly walking and trotting. Many horses kept for recreational riding would be included in the li...

  18. Spectral Quantitation Of Hydroponic Nutrients

    Schlager, Kenneth J.; Kahle, Scott J.; Wilson, Monica A.; Boehlen, Michelle

    1996-01-01

    Instrument continuously monitors hydroponic solution by use of absorption and emission spectrometry to determine concentrations of principal nutrients, including nitrate, iron, potassium, calcium, magnesium, phosphorus, sodium, and others. Does not depend on extraction and processing of samples, use of such surrograte parameters as pH or electrical conductivity for control, or addition of analytical reagents to solution. Solution not chemically altered by analysis and can be returned to hydroponic process stream after analysis.

  19. Nutrient cycling in mango trees

    Cinara Xavier de Almeida

    2014-02-01

    Full Text Available Estimates of nutrient amounts both shedding and demanding replacement in the maintenance of productivity of fruit trees require studies on element dynamics within the many ecosystem components generally made up of nutrient cycling. Thus, it was the objective of this study to evaluate the nutrient biochemical cycling in a mango tree (Mangifera indica L. orchard, Palmer variety. Macronutrients [nitrogen (N, phosphorus (P, potassium (K, calcium (Ca, magnesium (Mg, and sulfur (S] had their contents evaluated in leaves at different stages: new, mature, senescent, and litter. First exploratory analysis was performed for main components which preserve the multivariate structure shown by the data. It was possible to observe the association of new leaves with N, P, K, Mg, and S; senescent leaves and the leaves from the litter were associated to Ca, while mature leaves, to K. As a complement, taking the independent variables into consideration, Tukey test (p?0.01 showed that the averages of N, P, and Ca differ between the new and the mature leaves; average of Mg in new leaves differs from the others, and S does not differ along the stages. Also observed was the re-translocation of 41%, 63% and 57% of N, P, and K, respectively, when comparison was made among the contents of the elements in mature leaves as well as in litter, which indicates that the biochemical cycling is important for the mango tree cultivation.

  20. Proposal for a method to estimate nutrient shock effects in bacteria

    Azevedo Nuno F

    2012-08-01

    Full Text Available Abstract Background Plating methods are still the golden standard in microbiology; however, some studies have shown that these techniques can underestimate the microbial concentrations and diversity. A nutrient shock is one of the mechanisms proposed to explain this phenomenon. In this study, a tentative method to assess nutrient shock effects was tested. Findings To estimate the extent of nutrient shock effects, two strains isolated from tap water (Sphingomonas capsulata and Methylobacterium sp. and two culture collection strains (E. coli CECT 434 and Pseudomonas fluorescens ATCC 13525 were exposed both to low and high nutrient conditions for different times and then placed in low nutrient medium (R2A and rich nutrient medium (TSA. The average improvement (A.I. of recovery between R2A and TSA for the different times was calculated to more simply assess the difference obtained in culturability between each medium. As expected, A.I. was higher when cells were plated after the exposition to water than when they were recovered from high-nutrient medium showing the existence of a nutrient shock for the diverse bacteria used. S. capsulata was the species most affected by this phenomenon. Conclusions This work provides a method to consistently determine the extent of nutrient shock effects on different microorganisms and hence quantify the ability of each species to deal with sudden increases in substrate concentration.

  1. Nutrient Shielding in Clusters of Cells

    Lavrentovich, Maxim O; Nelson, David R

    2013-01-01

    Cellular nutrient consumption is influenced by both the nutrient uptake kinetics of an individual cell and the cells' spatial arrangement. Large cell clusters or colonies have inhibited growth at the cluster's center due to the shielding of nutrients by the cells closer to the surface. We develop an effective medium theory that predicts a thickness $\\ell$ of the outer shell of cells in the cluster that receives enough nutrient to grow. The cells are treated as partially absorbing identical spherical nutrient sinks, and we identify a dimensionless parameter $\

  2. Collection assessment and acquisitions budgets

    Lee, Sul H

    2013-01-01

    This invaluable new book contains timely information about the assessment of academic library collections and the relationship of collection assessment to acquisition budgets. The rising cost of information significantly influences academic libraries'abilities to acquire the necessary materials for students and faculty, and public libraries'abilities to acquire material for their clientele. Collection Assessment and Acquisitions Budgets examines different aspects of the relationship between the assessment of academic library collections and the management of library acquisition budgets. Librar

  3. Distributed Data Acquisition For Biomechanics Research

    Myklebust, J.; Geisler, M.; Prieto, T.; Weiss, R.

    1987-01-01

    Biomechanics research at the Medical College of Wisconsin is directed to the determination of the mechanisms of head and spine injury and the evaluation of surgical treatments for these injuries. This work involves mechanical testing of components of the spine (disks, vertebral bodies, and ligaments) as well as testing of composite spines and in situ evaluation of intact human cadavers (1,3). Other studies utilize experimental animals to measure neurologic and physiologic effects due to injury producing loads and accelerations (2). An integrated system has been developed to facilitate the acquisition and analysis of the diverse types of data from these experiments.

  4. Electronics and data acquisition

    High energy physics detectors span a wide range of applications with greatly differing requirements. Although the detector configurations are very different, the application of only a few basic signal acquisition principles is required. The LHC required novel designs, but built on a wide range of previous developments that had been completed for other experiments. The high luminosity drove up the event rates, but multiple interactions per bunch crossing also made occupancy a major challenge. The large scale of detector subsystems imposed efficient designs where cost was a major consideration, but the difficulty of accessing detector components added reliability to the list of more severe requirements. Radiation damage, especially in the inner detectors, added additional crucial constraints. This paper will discuss electronics requirements, the configurations of major LHC detectors, and the readout systems. After a discussion of front-end implementations and radiation effects, systems with extreme performance requirements are described in more detail, i.e. silicon strip and pixel systems.

  5. Plasmid acquisition in microgravity

    Juergensmeyer, Margaret A.; Juergensmeyer, Elizabeth A.; Guikema, James A.

    1995-01-01

    In microgravity, bacteria often show an increased resistance to antibiotics. Bacteria can develop resistance to an antibiotic after transformation, the acquisition of DNA, usually in the form of a plasmid containing a gene for resistance to one or more antibiotics. In order to study the capacity of bacteria to become resistant to antibiotics in microgravity, we have modified the standard protocol for transformation of Escherichia coli for use in the NASA-flight-certified hardware package, The Fluid Processing Apparatus (FPA). Here we report on the ability of E. coli to remain competent for long periods of time at temperatures that are readily available on the Space Shuttle, and present some preliminary flight results.

  6. Language Acquisition in Computers

    Belzner, Megan; Roman, Jorge H

    2012-01-01

    This project explores the nature of language acquisition in computers, guided by techniques similar to those used in children. While existing natural language processing methods are limited in scope and understanding, our system aims to gain an understanding of language from first principles and hence minimal initial input. The first portion of our system was implemented in Java and is focused on understanding the morphology of language using bigrams. We use frequency distributions and differences between them to define and distinguish languages. English and French texts were analyzed to determine a difference threshold of 55 before the texts are considered to be in different languages, and this threshold was verified using Spanish texts. The second portion of our system focuses on gaining an understanding of the syntax of a language using a recursive method. The program uses one of two possible methods to analyze given sentences based on either sentence patterns or surrounding words. Both methods have been i...

  7. Generalized Nutrient Taxes Can Increase Consumer Welfare.

    Bishai, David

    2015-11-01

    Certain nutrients can stimulate appetite making them fattening in a way that is not fully conveyed by the calorie content on the label. For rational eaters, this information gap could be corrected by more labeling. As an alternative, this paper proposes a set of positive and negative taxes on the fattening and slimming nutrients in food rather than on the food itself. There are conditions under which this tax plus subsidy system could increase welfare by stopping unwanted weight gain while leaving the final retail price of food unchanged. A nutrient tax system could improve welfare if fattening nutrients, net of their effect on weight, are inferior goods and the fiscal cost of administering the tax is sufficiently low. More data on the price elasticity of demand for nutrients as well as data on how specific nutrients affect satiety and how total calorie intake would be necessary before one could be sure a nutrient tax would work in practice. PMID:25241653

  8. 翠菊根系养分捕获形态塑性及其生理机制%Root nutrient foraging of morphological plasticity and physiological mechanism in Callistephus chinensis

    董佳; 牟溥

    2012-01-01

    养分捕获塑性机制.%Aims Previous studies discovered unusual plasticity in root growth of Callistephus chinensis, in that fewer fine roots grow in pulse soil nutrient patches than in unfertilized patches. Our goal is to interpret this event via experimentation following the theory of plant physiological ecology. The experiment tested the following hypotheses: NO3 -, NH4+ and method of application 1) significantly affect root growth and 2) significantly affect root hormones and 3) root hormones (auxin (IAA), abscisic acid (ABA), and cytokinin (zeatin riboside + zeatin) (CK. (ZR + Z))) significantly affect root architecture (indicated by the length of the 1st order fine roots, the inter 1st order root length and the density of the 1st order fine lateral roots). Methods The water culture approach was employed with treatments of two fertilizers (NO3- and NH4+), two methods of application (stable vs. pulse, i.e., pulse shift to high N concentration from low and mid concentration) and low, mid and high concentrations of the fertilizers (NO3-: 0.2, 1.0 and 18.0 mmol·L-1; NH4+: 0.2, 4.0 and 20.0 mmol·L-1). The experiment lasted 35 days after the treatments, the plants were harvested by the end of the experiment and all concerned parameters were measured including root mass, the above-mentioned root architecture parameters and the contents of root hormones. Important findings The experimental treatments affected root mass and root hormones with different significances. The high concentrations of NO3- and NH4+ both greatly lowered the root mass and IAA. Values were lower in the NH4+ culture than in the NO3- one. Pulse shift treatment lowered both further. CK (ZR + Z) contents did not respond to the concentrations and the methods of application, but to NO3- or NH4+ the latter led much lower CK (ZR + Z) contents than the former. Root mass had positive regression relationships with 1st order root length and the density of the fine lateral roots, had a linear regression relationship with IAA, a negative

  9. Zinc piracy as a mechanism of Neisseria meningitidis for evasion of nutritional immunity.

    Stork, Michiel; Grijpstra, Jan; Bos, Martine P; Mañas Torres, Carmen; Devos, Nathalie; Poolman, Jan T; Chazin, Walter J; Tommassen, Jan

    2013-10-01

    The outer membrane of Gram-negative bacteria functions as a permeability barrier that protects these bacteria against harmful compounds in the environment. Most nutrients pass the outer membrane by passive diffusion via pore-forming proteins known as porins. However, diffusion can only satisfy the growth requirements if the extracellular concentration of the nutrients is high. In the vertebrate host, the sequestration of essential nutrient metals is an important defense mechanism that limits the growth of invading pathogens, a process known as "nutritional immunity." The acquisition of scarce nutrients from the environment is mediated by receptors in the outer membrane in an energy-requiring process. Most characterized receptors are involved in the acquisition of iron. In this study, we characterized a hitherto unknown receptor from Neisseria meningitidis, a causative agent of sepsis and meningitis. Expression of this receptor, designated CbpA, is induced when the bacteria are grown under zinc limitation. We demonstrate that CbpA functions as a receptor for calprotectin, a protein that is massively produced by neutrophils and other cells and that has been shown to limit bacterial growth by chelating Zn²⁺ and Mn²⁺ ions. Expression of CbpA enables N. meningitidis to survive and propagate in the presence of calprotectin and to use calprotectin as a zinc source. Besides CbpA, also the TonB protein, which couples energy of the proton gradient across the inner membrane to receptor-mediated transport across the outer membrane, is required for the process. CbpA was found to be expressed in all N. meningitidis strains examined, consistent with a vital role for the protein when the bacteria reside in the host. Together, our results demonstrate that N. meningitidis is able to subvert an important defense mechanism of the human host and to utilize calprotectin to promote its growth. PMID:24204275

  10. Zinc piracy as a mechanism of Neisseria meningitidis for evasion of nutritional immunity.

    Michiel Stork

    2013-10-01

    Full Text Available The outer membrane of Gram-negative bacteria functions as a permeability barrier that protects these bacteria against harmful compounds in the environment. Most nutrients pass the outer membrane by passive diffusion via pore-forming proteins known as porins. However, diffusion can only satisfy the growth requirements if the extracellular concentration of the nutrients is high. In the vertebrate host, the sequestration of essential nutrient metals is an important defense mechanism that limits the growth of invading pathogens, a process known as "nutritional immunity." The acquisition of scarce nutrients from the environment is mediated by receptors in the outer membrane in an energy-requiring process. Most characterized receptors are involved in the acquisition of iron. In this study, we characterized a hitherto unknown receptor from Neisseria meningitidis, a causative agent of sepsis and meningitis. Expression of this receptor, designated CbpA, is induced when the bacteria are grown under zinc limitation. We demonstrate that CbpA functions as a receptor for calprotectin, a protein that is massively produced by neutrophils and other cells and that has been shown to limit bacterial growth by chelating Zn²⁺ and Mn²⁺ ions. Expression of CbpA enables N. meningitidis to survive and propagate in the presence of calprotectin and to use calprotectin as a zinc source. Besides CbpA, also the TonB protein, which couples energy of the proton gradient across the inner membrane to receptor-mediated transport across the outer membrane, is required for the process. CbpA was found to be expressed in all N. meningitidis strains examined, consistent with a vital role for the protein when the bacteria reside in the host. Together, our results demonstrate that N. meningitidis is able to subvert an important defense mechanism of the human host and to utilize calprotectin to promote its growth.

  11. Tracer technology in nutrient management strategies for sustainable crop production

    The use of tracers in soil-plant studies has been found to provide quantitative and accurate data, which are essential for understanding the dynamics of soil nutrients and for evaluating the efficiency of fertilizer sources and other management practices. Although there is fairly good understanding of the management of inorganic fertilizers for crop production in acid soils, much less information is available on the management of organic forms of these nutrients, while data on interactions of the two forms is very much limited. Understanding the underlying processes in these strategies using conventional methods is most often difficult, but isotope tracers (both radioactive and stable isotopes) have been found to be useful in unraveling the mechanisms associated with nutrient availability, fertilizer use efficiency, losses and residual effects, as well as the role. of legumes in farming systems, and in identifying varietal differences in nutrient use efficiency. The first extensive use of isotope as tracers in plant nutrition was made in the 1940s. The radioactive isotope of P (32P) was used to study the utilization of P fertilizers by various crops in a series of greenhouse experiments (1) and field trials (2). In Malaysian, the use of isotopes to study nutrient management for crop production started in 1969 when the Rubber Research Institute was involved in study the root activity of rubber trees (3). The next attempt in using isotopes to study nutrient management problems only started in 1980s with the assistance of the International Atomic Energy Agency (IAEA) and the Malaysian Institute for Nuclear Technology Research (MINT). Some of the relevant findings and their links to the development and implementation of sustainable land, management strategies for crop production are highlighted. (Author)

  12. Merger and Acquisition Market: from World Experience to National Practice

    Hrechana Svitlana I.; Hrinchuk Kateryna S.

    2014-01-01

    The goal of the article lies in identification of tendencies and prospects of development of the merger and acquisition market of Ukraine in the context of influence of the world M and A experience upon this process under conditions of globalisation. In the result of the study the article analyses the most significant merger and acquisition operations that took place in the world practice and in Ukraine in recent years. The article reveals and deeply assesses the variety of motives and mechan...

  13. Nutrient needs of performance horses

    Laurie Lawrence

    2008-07-01

    Full Text Available In 1989, the National Research Council (NRC Subcommittee on Horse Nutrition defined three categories of exercise: light, moderate or intense. In the 6th revised edition of "The Nutrient Requirements of Horses" (NRC, 2007, there are four categories for exercising horses: light exercise, moderate exercise, heavy exercise and very heavy exercise. Light exercise is described as 1 to 3 hours/week of mostly walking and trotting. Many horses kept for recreational riding would be included in the light exercise category. Moderate exercise consists of 3 to 5 hours/week of mostly trotting with some walking, some cantering and possibly some jumping or other type of more difficult activity. Horses used for horse shows, ranch work and frequent recreational riding would fit into the moderate exercise category. Heavy exercise is described as 4 to 5 hours/week of trotting, cantering, galloping and some jumping, cattle work, etc. Horses engaged in three day eventing, polo, endurance racing or other competitive events would be in this category. The very heavy exercise category includes racehorses and a few other horses that compete at the elite level of endurance or three day eventing. The NRC (2007 provides recommendations for nutrient intakes by mature exercising horses and for yearlings and two year olds that are receiving regular exercise. Many of the recommendations are similar to those in the 1989 publication, but others have been increased or decreased. For example, crude protein recommendations for exercising horses are generally lower than in the last edition. However, lysine requirements are relatively similar and the publication suggests that protein quality should be emphasized more than in the past. The 2007 NRC contains more information about the factors that influence the requirements for each nutrient, making it easier for users to develop diets for individual horses.

  14. First and Second Language Acquisition

    任海燕

    2007-01-01

    Though there are similarities between child first language acquisition and adult second language acquisition,this paper explores the differences between these two processes from several aspects and gives the suggestions that how we language teachers teach L2 students well in language teaching.

  15. The COMPASS data acquisition system

    Fischer, H; Grünemaier, A; Heinsius, F H; Hoffmann, M; Karstens, F; Kastaun, W; Königsmann, K C; Niebuhr, M; Risken, R; Schmidt, T; Schmitt, H; Schweimler, A; Hodenberg, M V; Urban, H J

    2002-01-01

    A fully pipelined and massively parallel data acquisition system has been developed for the COMPASS experiment at CERN. The main requirements are to read 250000 detector channels at a trigger rate of up to 100 kHz. Such high rates are only possible when using a hit selection mechanism on the front-end combined with dead-time free readout. For this purpose, a time-to-digital converter (TDC) chip has been developed and is used for all time measurement applications in COMPASS. Distributed, field programmable gate array (FPGA)-based readout-driver modules handle parallel front-end initialization, synchronous trigger and control-signal distribution, and local event building at a processing speed of 160 Mbyte/s. Each of the 160 readout-driver modules connects to 16 front-end boards through independent twisted pair cables (CAT 7, 600 MHz) or optical fibers using an industrial (ESCON), self synchronizing link at 40 Mbyte/s. Automatic configuration through unique module and link identification ensures the flexibility ...

  16. A Lossless Network for Data Acquisition

    AUTHOR|(SzGeCERN)698154; The ATLAS collaboration; Lehmann Miotto, Giovanna

    2016-01-01

    The bursty many-to-one communication pattern, typical for data acquisition systems, is particularly demanding for commodity TCP/IP and Ethernet technologies. We expand the study of lossless switching in software running on commercial-off-the-shelf servers, using the ATLAS experiment as a case study. In this paper we extend the popular software switch, Open vSwitch, with a dedicated, throughput-oriented buffering mechanism for data acquisition. We compare the performance under heavy congestion on typical Ethernet switches to a commodity server acting as a switch. Our results indicate that software switches with large buffers perform significantly better. Next, we evaluate the scalability of the system when building a larger topology of interconnected software switches, exploiting the integration with software-defined networking technologies. We build an IP-only leaf-spine network consisting of eight software switches running on separate physical servers as a demonstrator.

  17. Smart data acquisition system for utilities metering

    Ileana, I.; Risteiu, M.; Tulbure, A.; Rusu, M.

    2009-01-01

    The paper approaches the task of automatically reading and recognition of registered data on the utility meters of the users and is a part of a more complex project of our team concerning the remote data acquisition from industrial processes. A huge amount of utility meters in our country is of mechanical type without remote acquiring facilities and as an intermediate solution we propose an intelligent optical acquisition system which will store the read values in desktop and mobile devices. The main requirements of such a system are: portability, data reading accuracy, fast processing and energy independence. The paper analyses several solutions (including Artificial Neural Networks approach) tested by our team and present the experimental results and our conclusions.

  18. Incidental Lexicon Acquisition through Playful Interaction

    Lukas Wilhelm Ansteeg

    2015-02-01

    Full Text Available This paper presents an educational game which aids learners with foreign lexicon acquisition while entertaining them at the same time. An overview over existing language learning tools is given, and a general platform for educational games for second language acquisition (SLA is described. It introduces a specific prototype video game which teaches Italian vocabulary to the user. The application puts learning at the core of its game mechanics and combines it with a narrative and role-playing elements. In a user study, the game is compared to two other learning methods with focus on long term retention of vocabulary and enjoyment of the exercise. The game is found to perform within 10% of the efficiency of pure vocabulary learning exercises, while being considerably more enjoyable to the user.

  19. DATA ACQUISITION (DAQ)

    Gerry Bauer

    The CMS Storage Manager System The tail-end of the CMS Data Acquisition System is the Storage Manger (SM), which collects output from the HLT and stages the data at Cessy for transfer to its ultimate home in the Tier-0 center. A SM system has been used by CMS for several years with the steadily evolving software within the XDAQ framework, but until relatively recently, only with provisional hardware. The SM is well known to much of the collaboration through the ‘MiniDAQ’ system, which served as the central DAQ system in 2007, and lives on in 2008 for dedicated sub-detector commissioning. Since March of 2008 a first phase of the final hardware was commissioned and used in CMS Global Runs. The system originally planned for 2008 aimed at recording ~1MB events at a few hundred Hz. The building blocks to achieve this are based on Nexsan's SATABeast storage array - a device  housing up to 40 disks of 1TB each, and possessing two controllers each capable of almost 200 MB/sec throughput....

  20. Brain foods: the effects of nutrients on brain function

    Gómez-Pinilla, Fernando

    2008-01-01

    It has long been suspected that the relative abundance of specific nutrients can affect cognitive processes and emotions. Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that are responsible for the action of diet on brain health and mental function. Several gut hormones that can enter the brain, or that are produced in the brain itself, influence cognitive ability. In addition, well-established regulators o...

  1. 48 CFR 3034.004 - Acquisition strategy.

    2010-10-01

    ... Acquisition strategy. See (HSAR) 48 CFR 3009.570 for policy applicable to acquisition strategies that consider... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Acquisition strategy. 3034.004 Section 3034.004 Federal Acquisition Regulations System DEPARTMENT OF HOMELAND SECURITY,...

  2. 48 CFR 234.004 - Acquisition strategy.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Acquisition strategy. 234..., DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION 234.004 Acquisition strategy. (1) See 209.570 for policy applicable to acquisition strategies that consider the use of lead...

  3. 48 CFR 34.004 - Acquisition strategy.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Acquisition strategy. 34... CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION General 34.004 Acquisition strategy. The program manager, as specified in agency procedures, shall develop an acquisition strategy tailored to the...

  4. 48 CFR 434.004 - Acquisition strategy.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Acquisition strategy. 434.004 Section 434.004 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE SPECIAL CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION General 434.004 Acquisition strategy. (a) The...

  5. 48 CFR 873.105 - Acquisition planning.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Acquisition planning. 873... planning. (a) Acquisition planning is an indispensable component of the total acquisition process. (b) For... particular acquisition expected to exceed the SAT. The team should consist of a mix of staff, appropriate...

  6. Nutrient and energy sensing in skeletal muscle

    Deshmukh, Atul S.

    2009-01-01

    Nutrient overload and physical inactivity often leads to the development of obesity and type 2 diabetes. Acute over-nutrition can induce insulin resistance, while physical exercise enhances skeletal muscle insulin sensitivity. Like every living cell, skeletal muscle senses nutrient and energy signals and to adjust metabolic flux. This thesis focuses on some of the key nutrient and energy sensing (exercise/contraction-induced) pathways in skeletal muscle that regulate metabol...

  7. Demand for Nutrients: The Household Production Approach

    Chung, Rebecca H.; Lee, Jonq-Ying; Mark G. Brown

    1998-01-01

    This study uses the household production theory to study the demand for nutrients, i.e., households purchase a combination of food items from the market and produce the needed nutrients from these food items. By following the traditional household production approach, shadow prices for nutrients in food consumption are calculated. The cost function that generates the shadow prices appears plausible in terms of its elasticities of substitution and factor demand. After obtaining the calculated ...

  8. Methane productivity and nutrient recovery from manure

    Moeller, H.B.

    2003-07-01

    The efficient recovery of energy and improvements in the handling of nutrients from manure have attracted increased research focus during recent decades. Anaerobic digestion is a key process in any strategy for the recovery of energy, while slurry separation is an important component in an improved nutrient-handling strategy. This thesis is divided into two parts: the first deals mainly with nutrient recovery strategies and the second examines biological degradation processes, including controlled anaerobic digestion. (au)

  9. 75 FR 8272 - Defense Federal Acquisition Regulation Supplement; Acquisition Strategies To Ensure Competition...

    2010-02-24

    ...DoD is issuing an interim rule amending the Defense Federal Acquisition Regulation Supplement (DFARS) to implement the Weapon Systems Acquisition Reform Act of 2009, section 202, Acquisition Strategies to Ensure Competition throughout the Lifecycle of Major Defense Acquisition...

  10. Nutrient availability moderates transpiration in Ehrharta calycina.

    Cramer, Michael D; Hoffmann, Vera; Verboom, G Anthony

    2008-01-01

    Transpiration-driven 'mass-flow' of soil-water can increase nutrient flow to the root surface. Here it was investigated whether transpiration could be partially regulated by nutrient status. Seeds of Ehrharta calycina from nine sites across a rainfall gradient were supplied with slow-release fertilizer dibbled into the sand surrounding the roots and directly available through interception, mass-flow and diffusion (dubbed 'interception'), or sequestered behind a 40-microm mesh and not directly accessible by the roots, but from which nutrients could move by diffusion or mass-flow (dubbed 'mass-flow'). Although mass-flow plants were significantly smaller than interception plants as a consequence of nutrient limitation, they transpired 60% faster, had 90% higher photosynthesis relative to transpiration (A/E), and 40% higher tissue P, Ca and Na concentrations than plants allowed to intercept nutrients directly. Tissue N and K concentrations were similar for interception and mass-flow plants. Transpiration was thus higher in the nutrient-constrained 'mass-flow' plants, increasing the transport of nutrients to the roots by mass-flow. Transpiration may have been regulated by N availability, resulting in similar tissue concentration between treatments. It is concluded that, although transpiration is a necessary consequence of photosynthetic CO(2) uptake in C(3) plants, plants can respond to nutrient limitation by varying transpiration-driven mass-flow of nutrients. PMID:18537891

  11. Dynamics of soil nutrients in larch plantations

    Yan Deren; Chen Jinglian

    1999-01-01

    The annual dynamic changes of soil nutrients were measured in pure larch plantation and in mixed larch plantation in the arboretum of Inner Mongolia Academy of Forestry Science, Huhehaote. The results showed that soil nutrients in pure larch plantations changed rapidly in July and August. The variation of soil nutrients is more stable in mixed larch plantation. Compared with the pure larch plantation, the content of soil nutrients in mixed larch plantation obviously increased. The soil degradation occurred in the pure larch plantation, and related to the forest age.

  12. Vigorous Root Growth Is a Better Indicator of Early Nutrient Uptake than Root Hair Traits in Spring Wheat Grown under Low Fertility

    Wang, Yaosheng; Thorup-Kristensen, Kristian; Jensen, Lars Stoumann; Magid, Jakob

    2016-01-01

    A number of root and root hair traits have been proposed as important for nutrient acquisition. However, there is still a need for knowledge on which traits are most important in determining macro- and micronutrient uptake at low soil fertility. This study investigated the variations in root growth vigor and root hair length (RHL) and density (RHD) among spring wheat genotypes and their relationship to nutrient concentrations and uptake during early growth. Six spring wheat genotypes were gro...

  13. Automated ship image acquisition

    Hammond, T. R.

    2008-04-01

    The experimental Automated Ship Image Acquisition System (ASIA) collects high-resolution ship photographs at a shore-based laboratory, with minimal human intervention. The system uses Automatic Identification System (AIS) data to direct a high-resolution SLR digital camera to ship targets and to identify the ships in the resulting photographs. The photo database is then searchable using the rich data fields from AIS, which include the name, type, call sign and various vessel identification numbers. The high-resolution images from ASIA are intended to provide information that can corroborate AIS reports (e.g., extract identification from the name on the hull) or provide information that has been omitted from the AIS reports (e.g., missing or incorrect hull dimensions, cargo, etc). Once assembled into a searchable image database, the images can be used for a wide variety of marine safety and security applications. This paper documents the author's experience with the practicality of composing photographs based on AIS reports alone, describing a number of ways in which this can go wrong, from errors in the AIS reports, to fixed and mobile obstructions and multiple ships in the shot. The frequency with which various errors occurred in automatically-composed photographs collected in Halifax harbour in winter time were determined by manual examination of the images. 45% of the images examined were considered of a quality sufficient to read identification markings, numbers and text off the entire ship. One of the main technical challenges for ASIA lies in automatically differentiating good and bad photographs, so that few bad ones would be shown to human users. Initial attempts at automatic photo rating showed 75% agreement with manual assessments.

  14. Data acquisition techniques using PC

    Austerlitz, Howard

    1991-01-01

    Data Acquisition Techniques Using Personal Computers contains all the information required by a technical professional (engineer, scientist, technician) to implement a PC-based acquisition system. Including both basic tutorial information as well as some advanced topics, this work is suitable as a reference book for engineers or as a supplemental text for engineering students. It gives the reader enough understanding of the topics to implement a data acquisition system based on commercial products. A reader can alternatively learn how to custom build hardware or write his or her own software.

  15. SWRL: Rule Acquisition Using Ontology

    Plinere, D; Borisovs, A

    2009-01-01

    Nowadays rule-based systems are very common. The use of ontology-based systems is becoming ever more popular, especially in addition to the rule-based one. The most widely used ontology development platform is Protégé. Protégé provides a knowledge acquisition tool, but still the main issue of the ontologybased rule system is rule acquisition. This paper presents an approach to using SWRL rules Tab, a plug-in to Protégé, for rule acquisition. SWRL rules Tab transforms conj...

  16. Foreign Acquisition, Wages and Productivity

    Bandick, Roger

    This paper studies the effect of foreign acquisition on wages and total factor productivity (TFP) in the years following a takeover by using unique detailed firm-level data for Sweden for the period 1993-2002. The paper takes particular account of the potential endogeneity of the acquisition...... no effects on overall, skilled or less-skilled wage growth neither in targeted Swedish MNEs nor in targeted Swedish non-MNEs and neither if the acquisition was motivated by vertical or horizontal motives. However, the results indicate that both targeted Swedish MNEs and non-MNEs have better growth in...

  17. Foreign Acquisition, Wages and Productivity

    Bandick, Roger

    2011-01-01

    This paper studies the effect of foreign acquisition on wages and total factor productivity (TFP) in the years following a takeover by using unique detailed firm-level data for Sweden for the period 1993-2002. The paper takes particular account of the potential endogeneity of the acquisition...... no effects on overall, skilled or less-skilled wage growth neither in targeted Swedish MNEs nor in targeted Swedish non-MNEs and neither if the acquisition was motivated by vertical or horizontal motives. However, the results indicate that both targeted Swedish MNEs and non-MNEs have better growth in...

  18. Invertebrate response to nutrient-driven epiphytic load increase in Posidonia oceanica meadows

    Castejón-Silvo, Inés; Domínguez, Marta; Terrados, Jorge; Tomas, Fiona; Morales-Nin, Beatriz

    2012-10-01

    Nutrient increases in coastal systems are becoming a world-wide concern since they promote strong structural and functional changes in shallow ecosystems. Increased nutrient availability in the water column may strongly enhance the leaf epiphytic communities of key habitat-forming species such as seagrasses through a bottom-up mechanism, competing for light and nutrients with the leaves. Epiphytes support an abundant and diverse community of resident invertebrates which fuel higher trophic levels in Posidonia oceanica food webs. We evaluated the response of seagrass, epiphytes and the invertebrate community to an experimental increase of water column nutrient availability. Nutrient increase was followed by a rise of epiphyte biomass. The increase in epiphytic biomass promoted invertebrate abundance, but appeared to have negative effects on P. oceanica shoot size. On the other hand, the increase in invertebrate abundance did not seem to control epiphytic biomass, which was not reversed to pre-nutrient enrichment levels. This work suggests that the abundance of invertebrate populations is limited by epiphyte biomass, through food or habitat provision, in P. oceanica systems and points to nutrients as the main driver of epiphyte biomass during summer. The results illustrate the control mechanisms at community level in P. oceanica meadows and the possible responses of a threatened ecosystem to human impact such as eutrophication.

  19. Data needs for nutrient balances

    Vinther, Finn Pilgaard

    One of the tools for evaluating the results of environmental action plans or EU directives related to nutrients in the agricultural sector is to follow the development of annually estimated nitrogen (N) and phosphorus (P) balances and surplus. Unlike greenhouse gas and ammonia emissions, countries...... are not required to report N and P balances for agriculture as part of any international conventions. As a consequence, there is no organisation equivalent to the Intergovernmental Panel on Climate Change (IPCC) or United Nations Economic Commission for Europe (UNECE) who has responsibility for...... standardising and improving the methodology to calculate such balances. However, Eurostat and OECD have jointly established a standard for using a gross N balances, and the soil N balance calculated by the CAPRI model has gained acceptance in European policymaking. It can be mentioned that the Task Force on...

  20. Solar light, seawater temperature, and nutrients, which one is more important in affecting phytoplankton growth?

    Miao Zhenqing; Yang Dongfang

    2009-01-01

    Based on research results on the impacts of solar light, seawater temperature, and nutrient available to phytoplankton growth and changes in phytoplankton physiology and assemblage, we discussed the order of influence of these factors. By clarifying the mechanisms and processes of the impacts by these factors, we have determined the rising order of the importance as solar light, seawater temperature, and nutrient silicon (Si). Therefore, for human interests in sustaining economic development, the first thing to be considered is the input of nutrient Si into the ocean, followed by seawater temperature change.

  1. Gene Acquisition Convergence between Entomopoxviruses and Baculoviruses

    Julien Thézé

    2015-04-01

    Full Text Available Organisms from diverse phylogenetic origins can thrive within the same ecological niches. They might be induced to evolve convergent adaptations in response to a similar landscape of selective pressures. Their genomes should bear the signature of this process. The study of unrelated virus lineages infecting the same host panels guarantees a clear identification of phyletically independent convergent adaptation. Here, we investigate the evolutionary history of genes in the accessory genome shared by unrelated insect large dsDNA viruses: the entomopoxviruses (EPVs, Poxviridae and the baculoviruses (BVs. EPVs and BVs have overlapping ecological niches and have independently evolved similar infection processes. They are, in theory, subjected to the same selective pressures from their host’s immune responses. Their accessory genomes might, therefore, bear analogous genomic signatures of convergent adaption and could point out key genomic mechanisms of adaptation hitherto undetected in viruses. We uncovered 32 homologous, yet independent acquisitions of genes originating from insect hosts, different eukaryotes, bacteria and viruses. We showed different evolutionary levels of gene acquisition convergence in these viruses, underlining a continuous evolutionary process. We found both recent and ancient gene acquisitions possibly involved to the adaptation to both specific and distantly related hosts. Multidirectional and multipartite gene exchange networks appear to constantly drive exogenous gene assimilations, bringing key adaptive innovations and shaping the life histories of large DNA viruses. This evolutionary process might lead to genome level adaptive convergence.

  2. Rapid Material Appearance Acquisition Using Consumer Hardware

    Jiří Filip

    2014-10-01

    Full Text Available A photo-realistic representation of material appearance can be achieved by means of bidirectional texture function (BTF capturing a material’s appearance for varying illumination, viewing directions, and spatial pixel coordinates. BTF captures many non-local effects in material structure such as inter-reflections, occlusions, shadowing, or scattering. The acquisition of BTF data is usually time and resource-intensive due to the high dimensionality of BTF data. This results in expensive, complex measurement setups and/or excessively long measurement times. We propose an approximate BTF acquisition setup based on a simple, affordable mechanical gantry containing a consumer camera and two LED lights. It captures a very limited subset of material surface images by shooting several video sequences. A psychophysical study comparing captured and reconstructed data with the reference BTFs of seven tested materials revealed that results of our method show a promising visual quality. Speed of the setup has been demonstrated on measurement of human skin and measurement and modeling of a glue dessication time-varying process. As it allows for fast, inexpensive, acquisition of approximate BTFs, this method can be beneficial to visualization applications demanding less accuracy, where BTF utilization has previously been limited.

  3. Carbon rhizodeposition by plants of contrasting strategies for resource acquisition: responses to various nitrogen fertility regimes

    Baptist, Florence; Aranjuelo, I.; Lopez-Sangil, L.; Rovia, P.; Nogués, S.

    2010-05-01

    Rhizodeposition by plants is one of the most important physiological mechanisms related to carbon and nitrogen cycling which is also believed to vary along the acquisition-conservation continuum. However, owing to methodological difficulties (i.e. narrow zone of soil around roots and rapid assimilation by soil microbes), root exudation and variations between species are one of the most poorly understood belowground process. Although previous approaches such as hydroponic culture based system, permit the chemical analysis of exudates, the fact that this protocol is qualitative, conditions its utility (see review in Phillips et al. 2008). Others techniques based on pulse-labelling approach have been developed to quantify rhizodeposition but are rarely sufficient to uniformly label all plant inputs to soil. Consequently with this typical pulse chase methods, recent assimilates are labeled but the recalcitrant carbon will not be labeled and therefore the contribution of this carbon will not be considered. Hence, traditional pulse labelling is not a quantitative means of tracing carbon due to inhomogeneous labelling and so limits greatly comparative studies of rhizodeposition fluxes at the interspecific level. In this study we developped a new protocole based on a long-term (3 months) steady state 13C labelling in order (1) to quantify rhizodeposition fluxes for six graminoid species caracterized by contrasted nutrient acquisition strategies and (2) to investigate to what extent various level of nitrogen fertility regimes modulate rhizodeposition fluxes. This method will enable to quantify under natural soil conditions both the accumulation of 13C in the soil but also the quantity that has been respired by the microorganisms during a given time and so will give an integrated picture of rhizodeposition fluxes for each species under each nitrogen fertility level. Results are currently being processed and will be presented at the conference. References: Phillips RP, Erlitz

  4. BESII online data acquisition system

    The authors introduce the hardware configuration, software structure and upgrading of the BES online data acquisition system, and also report the run status and abilities of the online data monitor and analysis after upgrading

  5. New KENS data acquisition system

    In this report, the authors discuss a data acquisition system, KENSnet, which is newly introduced to the KENS facility. The criteria for the data acquisition system was about 1 MIPS for CPU speed and 150 Mbytes for storage capacity for a computer per spectrometer. VAX computers were chosen with their propreitary operating system, VMS. The Vax computers are connected by a DECnet network mediated by Ethernet. Front-end computers, Apple Macintosh Plus and Macintosh II, were chosen for their user-friendly manipulation and intelligence. New CAMAC-based data acquisition electronics were developed. The data acquisition control program (ICP) and the general data analysis program (Genie) were both developed at ISIS and have been installed. 2 refs., 3 figs., 1 tab

  6. Platform attitude data acquisition system

    Afzulpurkar, S.

    A system for automatic acquisition of underwater platform attitude data has been designed, developed and tested in the laboratory. This is a micro controller based system interfacing dual axis inclinometer, high-resolution digital compass...

  7. Portable Data Acquisition System Project

    National Aeronautics and Space Administration — Armstrong researchers have developed a portable data acquisition system (PDAT) that can be easily transported and set up at remote locations to display and archive...

  8. Microbial nutrient limitation in Arctic lakes in a permafrost landscape of southwest Greenland

    Burpee, B.; Saros, J. E.; Northington, R. M.; Simon, K. S.

    2016-01-01

    Permafrost is degrading across regions of the Arctic, which can lead to increases in nutrient concentrations in surface freshwaters. The oligotrophic state of many Arctic lakes suggests that enhanced nutrient inputs may have important effects on these systems, but little is known about microbial nutrient limitation patterns in these lakes. We investigated microbial extracellular enzyme activities (EEAs) to infer seasonal nutrient dynamics and limitation across 24 lakes in southwest Greenland during summer (June and July). From early to late summer, enzyme activities that indicate microbial carbon (C), nitrogen (N), and phosphorus (P) demand increased in both the epilimnia and hypolimnia by 74 % on average. Microbial investment in P acquisition was generally higher than that for N. Interactions among EEAs indicated that microbes were primarily P-limited. Dissolved organic matter (DOM, measured as dissolved organic carbon) was strongly and positively correlated with microbial P demand (R2 = 0.84 in July), while there were no relationships between DOM and microbial N demand. Microbial P limitation in June epilimnia (R2 = 0.67) and July hypolimnia (R2 = 0.57) increased with DOM concentration. The consistency of microbial P limitation from June to July was related to the amount of DOM present, with some low-DOM lakes becoming N-limited in July. Our results suggest that future changes in P or DOM inputs to these lakes are likely to alter microbial nutrient limitation patterns.

  9. Influence of Physiological Stress on Nutrient Stoichiometry in Larval Amphibians.

    Kirschman, Lucas J; Haslett, Savhannah; Fritz, Kelley A; Whiles, Matt R; Warne, Robin W

    2016-01-01

    Exposure to environmental stressors alters animal phenotypes as well as nutrient metabolism, assimilation, and excretion. While stress-induced shifts in nutrient processes are known to alter organismal carbon (C) and nitrogen (N) stoichiometry, there has been little exploration of how environmental factors influence phosphorous (P). A better understanding of how P cycling varies with animal physiological state may provide insight into across-scale processes, because P is essential to animal function and ecological processes such as production and decomposition. We tested the effects of predator stress and exogenous glucocorticoids on C∶N∶P stoichiometry of larval amphibians. Glucocorticoids altered nutrient stoichiometry, apparently by modulating ossification and renal function. This reduced whole-body P and significantly increased N∶P. Additionally, elevated glucocorticoids caused a long-term reduction in P excretion. This reduction may reflect an initial unmeasured loss of P that glucocorticoids induce over acute timescales. In contrast, exposure to predator cues had no effect on larval C∶N∶P stoichiometry, which highlights that different stressors have varied effects on the endocrine stress response. Predation, in particular, is ubiquitous in the environment; thus, larvae responding to predators have conserved mechanisms that likely prevent or minimize physiological disruption. These results demonstrate the differing physiological roles of N and P, distinct nutrient demands associated with amphibian metamorphosis, and the contrasting effects that different environmental factors have on the physiological stress response. Our results also suggest that anthropogenic changes to the environment that induce chronic stress in amphibians could affect the biogeochemistry of nutrient-poor environments where they may act as keystone species. PMID:27327181

  10. Overfishing and nutrient pollution interact with temperature to disrupt coral reefs down to microbial scales

    Zaneveld, Jesse R.; Burkepile, Deron E.; Shantz, Andrew A.; Pritchard, Catharine E.; McMinds, Ryan; Payet, Jérôme P.; Welsh, Rory; Correa, Adrienne M. S.; Nathan P Lemoine; Rosales, Stephanie; Fuchs, Corinne; Maynard, Jeffrey A; Thurber, Rebecca Vega

    2016-01-01

    International audience Losses of corals worldwide emphasize the need to understand what drives reef decline. Stressors such as overfishing and nutrient pollution may reduce resilience of coral reefs by increasing coral–algal competition and reducing coral recruitment, growth and survivorship. Such effects may themselves develop via several mechanisms, including disruption of coral microbiomes. Here we report the results of a 3-year field experiment simulating overfishing and nutrient pollu...