WorldWideScience

Sample records for acquisition mechanisms nutrient

  1. Plant and pathogen nutrient acquisition strategies

    Fatima, Urooj; Senthil-Kumar, Muthappa

    2015-01-01

    Nutrients are indispensable elements required for the growth of all living organisms including plants and pathogens. Phyllosphere, rhizosphere, apoplast, phloem, xylem, and cell organelles are the nutrient niches in plants that are the target of bacterial pathogens. Depending upon nutrients availability, the pathogen adapts various acquisition strategies and inhabits the specific niche. In this review, we discuss the nutrient composition of different niches in plants, the mechanisms involved ...

  2. Mechanical damage to pollen aids nutrient acquisition in Heliconius butterflies (Nymphalidae).

    Krenn, Harald W; Eberhard, Monika J B; Eberhard, Stefan H; Hikl, Anna-Laetitia; Huber, Werner; Gilbert, Lawrence E

    2009-12-01

    Neotropical Heliconius and Laparus butterflies actively collect pollen onto the proboscis and extract nutrients from it. This study investigates the impact of the processing behaviour on the condition of the pollen grains. Pollen samples (n = 72) were collected from proboscides of various Heliconius species and Laparus doris in surrounding habitats of the Tropical Research Station La Gamba (Costa Rica). Examination using a light microscope revealed that pollen loads contained 74.88 ± 53.67% of damaged Psychotria pollen, 72.04 ± 23.4% of damaged Psiguria/Gurania pollen, and 21.35 ± 14.5% of damaged Lantana pollen (numbers represent median ± first quartile). Damaged pollen grains showed deformed contours, inhomogeneous and/or leaking contents, or they were empty. Experiments with Heliconius and Laparus doris from a natural population in Costa Rica demonstrated that 200 min of pollen processing behaviour significantly increased the percentage of damaged pollen of Psychotria compared to pollen from anthers (P = 0.015, Z = -2.44, Mann-Whitney U-test). Examination of pollen loads from green house reared Heliconius butterflies resulted in significantly greater amounts of damaged Psiguria pollen after 200 min of processing behaviour compared to pollen from flowers (P < 0.001, Z = -4.583, Mann-Whitney U-test). These results indicate that pollen processing functions as extra oral digestion whereby pollen grains are ruptured to make the content available for ingestion.

  3. Nutrient Acquisition and Metabolism by Campylobacter jejuni

    Martin eStahl

    2012-02-01

    Full Text Available The gastrointestinal pathogen Campylobacter jejuni is able to colonize numerous different hosts and compete against the gut microbiota. To do this, it must be able to efficiently acquire sufficient nutrients from its environment to support its survival and rapid growth in the intestine. However, despite almost 50 years of research, many aspects as to how C. jejuni accomplishes this feat remain poorly understood. C. jejuni lacks many of the common metabolic pathways necessary for the use of glucose, galactose, or other carbohydrates upon which most other microbes thrive. It does however make efficient use of citric acid cycle intermediates and various amino acids. C. jejuni readily uses the amino acids aspartate, glutamate, serine, and proline, with certain strains also possessing additional pathways allowing for the use of glutamine and asparagine. More recent work has revealed that some C. jejuni strains can metabolize the sugar L-fucose. This finding has upset years of dogma that C. jejuni is an asaccharolytic organism. C. jejuni also possesses diverse mechanisms for the acquisition of various transition metals that are required for metabolic activities. In particular, iron acquisition is critical for the formation of iron-sulphur complexes. C. jejuni is also unique in possessing both molybdate and tungsten cofactored proteins and thus has an unusual regulatory scheme for these metals. Together these various metabolic and acquisition pathways help C. jejuni to compete and thrive in wide variety of hosts and environments.

  4. Nutrient acquisition and secondary metabolites in plant pathogenic fungi

    Droce, Aida

    and infection processes of these two distinct phytopathogens are described with special attention on the importance of uptake and reallocation of nutrients. Nutrient uptake from host plant is crucial for fungi to grow and proliferate and during several developmental processes nutrient reallocation, a mechanism...... called autophagy, is crucial. In this ph.d project autophagy and dipeptide transport in Fg and Bgh is assessed with respect to pathology, developmental processes and mycotoxins production. Several techniques within molecular biology, bioinformatics, microbiology, analytical chemistry and plant pathology...

  5. Neurobiological Mechanisms of Language Acquisition. Review Article.

    Pulvermuller, Friedemann; Schumann, John H.

    1994-01-01

    Specifies language acquisition processes in terms of brain mechanisms to explain the variable success achieved by early and late learners and proposes a brain-based model for language acquisition on the basis of the literature. Two conditions for full acquisition of a language are motivation and grammatical ability. The neural underpinnings for…

  6. 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

  7. 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.

  8. The contribution of nutrient metal acquisition and metabolism to Acinetobacter baumannii survival within the host.

    Mortensen, Brittany L; Skaar, Eric P

    2013-01-01

    Acinetobacter baumannii is a significant contributor to intensive care unit (ICU) mortality causing numerous types of infection in this susceptible ICU population, most notably ventilator-associated pneumonia. The substantial disease burden attributed to A. baumannii and the rapid acquisition of antibiotic resistance make this bacterium a serious health care threat. A. baumannii is equipped to tolerate the hostile host environment through modification of its metabolism and nutritional needs. Among these adaptations is the evolution of mechanisms to acquire nutrient metals that are sequestered by the host as a defense against infection. Although all bacteria require nutrient metals, there is diversity in the particular metal needs among species and within varying tissue types and bacterial lifecycles. A. baumannii is well-equipped with the metal homeostatic systems required for the colonization of a diverse array of tissues. Specifically, iron and zinc homeostasis is important for A. baumannii interactions with biotic surfaces and for growth within vertebrates. This review discusses what is currently known regarding the interaction of A. baumannii with vertebrate cells with a particular emphasis on the contributions of metal homeostasis systems. Overall, published research supports the utility of exploiting these systems as targets for the development of much-needed antimicrobials against this emerging infectious threat.

  9. The contribution of nutrient metal acquisition and metabolism to Acinetobacter baumannii survival within the host

    Brittany L Mortensen

    2013-12-01

    Full Text Available Acinetobacter baumannii is a significant contributor to intensive care unit (ICU mortality causing numerous types of infection in this susceptible ICU population, most notably ventilator-associated pneumonia. The substantial disease burden attributed to A. baumannii and the rapid acquisition of antibiotic resistance make this bacterium a serious health care threat. A. baumannii is equipped to tolerate the hostile host environment through modification of its metabolism and nutritional needs. Among these adaptations is the evolution of mechanisms to acquire nutrient metals that are sequestered by the host as a defense against infection. Although all bacteria require nutrient metals, there is diversity in the particular metal needs among species and within varying tissue types and bacterial lifecycles. A. baumannii is well-equipped with the metal homeostatic systems required for the colonization of a diverse array of tissues. Specifically, iron and zinc homeostasis is important for A. baumannii interactions with biotic surfaces and for growth within vertebrates. This review discusses what is currently known regarding the interaction of A. baumannii with vertebrate cells with a particular emphasis on the contributions of metal homeostasis systems. Overall, published research supports the utility of exploiting these systems as targets for the development of much-needed antimicrobials against this emerging infectious threat.

  10. Learning: Statistical Mechanisms in Language Acquisition

    Wonnacott, Elizabeth

    The grammatical structure of human languages is extremely complex, yet children master this complexity with apparent ease. One explanation is that we come to the task of acquisition equipped with knowledge about the possible grammatical structures of human languages—so-called "Universal Grammar". An alternative is that grammatical patterns are abstracted from the input via a process of identifying reoccurring patterns and using that information to form grammatical generalizations. This statistical learning hypothesis receives support from computational research, which has revealed that even low level statistics based on adjacent word co-occurrences yield grammatically relevant information. Moreover, even as adults, our knowledge and usage of grammatical patterns is often graded and probabilistic, and in ways which directly reflect the statistical makeup of the language we experience. The current chapter explores such evidence and concludes that statistical learning mechanisms play a critical role in acquisition, whilst acknowledging holes in our current knowledge, particularly with respect to the learning of `higher level' syntactic behaviours. Throughout, I emphasize that although a statistical approach is traditionally associated with a strongly empiricist position, specific accounts make specific claims about the nature of the learner, both in terms of learning mechanisms and the information that is primitive to the learning system. In particular, working models which construct grammatical generalizations often assume inbuilt semantic abstractions.

  11. Words, rules, and mechanisms of language acquisition.

    Endress, Ansgar D; Bonatti, Luca L

    2016-01-01

    We review recent artificial language learning studies, especially those following Endress and Bonatti (Endress AD, Bonatti LL. Rapid learning of syllable classes from a perceptually continuous speech stream. Cognition 2007, 105:247-299), suggesting that humans can deploy a variety of learning mechanisms to acquire artificial languages. Several experiments provide evidence for multiple learning mechanisms that can be deployed in fluent speech: one mechanism encodes the positions of syllables within words and can be used to extract generalization, while the other registers co-occurrence statistics of syllables and can be used to break a continuum into its components. We review dissociations between these mechanisms and their potential role in language acquisition. We then turn to recent criticisms of the multiple mechanisms hypothesis and show that they are inconsistent with the available data. Our results suggest that artificial and natural language learning is best understood by dissecting the underlying specialized learning abilities, and that these data provide a rare opportunity to link important language phenomena to basic psychological mechanisms. For further resources related to this article, please visit the WIREs website.

  12. Solute restriction reveals an essential role for clag3-associated channels in malaria parasite nutrient acquisition.

    Pillai, Ajay D; Nguitragool, Wang; Lyko, Brian; Dolinta, Keithlee; Butler, Michelle M; Nguyen, Son T; Peet, Norton P; Bowlin, Terry L; Desai, Sanjay A

    2012-12-01

    The plasmodial surface anion channel (PSAC) increases erythrocyte permeability to many solutes in malaria but has uncertain physiological significance. We used a PSAC inhibitor with different efficacies against channels from two Plasmodium falciparum parasite lines and found concordant effects on transport and in vitro parasite growth when external nutrient concentrations were reduced. Linkage analysis using this growth inhibition phenotype in the Dd2 × HB3 genetic cross mapped the clag3 genomic locus, consistent with a role for two clag3 genes in PSAC-mediated transport. Altered inhibitor efficacy, achieved through allelic exchange or expression switching between the clag3 genes, indicated that the inhibitor kills parasites through direct action on PSAC. In a parasite unable to undergo expression switching, the inhibitor selected for ectopic homologous recombination between the clag3 genes to increase the diversity of available channel isoforms. Broad-spectrum inhibitors, which presumably interact with conserved sites on the channel, also exhibited improved efficacy with nutrient restriction. These findings indicate that PSAC functions in nutrient acquisition for intracellular parasites. Although key questions regarding the channel and its biological role remain, antimalarial drug development targeting PSAC should be pursued.

  13. Age of acquisition: its neural and computational mechanisms.

    Hernandez, Arturo E; Li, Ping

    2007-07-01

    The acquisition of new skills over a life span is a remarkable human ability. This ability, however, is constrained by age of acquisition (AoA); that is, the age at which learning occurs significantly affects the outcome. This is most clearly reflected in domains such as language, music, and athletics. This article provides a perspective on the neural and computational mechanisms underlying AoA in language acquisition. The authors show how AoA modulates both monolingual lexical processing and bilingual language acquisition. They consider the conditions under which syntactic processing and semantic processing may be differentially sensitive to AoA effects in second-language acquisition. The authors conclude that AoA effects are pervasive and that the neural and computational mechanisms underlying learning and sensorimotor integration provide a general account of these effects.

  14. 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

  15. Disentangling value creation mechanism in cross-border acquisitions

    Wang, Daojuan; Sørensen, Olav Jull; Moini, Hamid

    2016-01-01

    important strategic dimensions for realizing synergy and creating value in CBAs . Furthermore, mediation analysis shows that the two acquisition-based dynamic capabilities—value identification and resource reconfiguration—act as important mediators in how the joining firms’ resource base impacts acquisition......This study investigates the value creation mechanism in cross-border acquisitions ( CBAs ) by employing a structural equation modeling technique and surveying 103 CBAs performed by Nordic firms. The results reveal that resource possession, resource picking, and resource utilization are three...... outcomes. The results shed light on the mechanisms through which the constructs influence value creation in CBAs and highlight the procedural and dynamic character of these determinants. The results also indicate that an integrative and process perspective, such as the “input-process-output” model proposed...

  16. Mechanisms of rule acquisition and rule following in inductive reasoning.

    Crescentini, Cristiano; Seyed-Allaei, Shima; De Pisapia, Nicola; Jovicich, Jorge; Amati, Daniele; Shallice, Tim

    2011-05-25

    Despite the recent interest in the neuroanatomy of inductive reasoning processes, the regional specificity within prefrontal cortex (PFC) for the different mechanisms involved in induction tasks remains to be determined. In this study, we used fMRI to investigate the contribution of PFC regions to rule acquisition (rule search and rule discovery) and rule following. Twenty-six healthy young adult participants were presented with a series of images of cards, each consisting of a set of circles numbered in sequence with one colored blue. Participants had to predict the position of the blue circle on the next card. The rules that had to be acquired pertained to the relationship among succeeding stimuli. Responses given by subjects were categorized in a series of phases either tapping rule acquisition (responses given up to and including rule discovery) or rule following (correct responses after rule acquisition). Mid-dorsolateral PFC (mid-DLPFC) was active during rule search and remained active until successful rule acquisition. By contrast, rule following was associated with activation in temporal, motor, and medial/anterior prefrontal cortex. Moreover, frontopolar cortex (FPC) was active throughout the rule acquisition and rule following phases before a rule became familiar. We attributed activation in mid-DLPFC to hypothesis generation and in FPC to integration of multiple separate inferences. The present study provides evidence that brain activation during inductive reasoning involves a complex network of frontal processes and that different subregions respond during rule acquisition and rule following phases.

  17. Production compilation : A simple mechanism to model complex skill acquisition

    Taatgen, N.A.; Lee, F.J.

    2003-01-01

    In this article we describe production compilation, a mechanism for modeling skill acquisition. Production compilation has been developed within the ACT-Rational (ACT-R; J. R. Anderson, D. Bothell, M. D. Byrne, & C. Lebiere, 2002) cognitive architecture and consists of combining and specializing tas

  18. Unbalanced Bilingual Acquisition as a Mechanism of Grammatical Change

    Matthews, Stephen; Yip, Virginia

    2011-01-01

    Bilingual first language acquisition (BFLA) has been considered a possible mechanism of contact-induced change in several recent studies (Siegel, 2008, p. 117; Satterfield, 2005, p. 2075; Thomason, 2001, p. 148; Yip & Matthews, 2007, p.15). There is as yet little consensus on the question, with divergent views regarding both BFLA at the individual…

  19. Enhancement of faba bean competitive ability by arbuscular mycorrhizal fungi is highly correlated with dynamic nutrient acquisition by competing wheat

    Qiao, Xu; Bei, Shuikuan; Li, Chunjie; Dong, Yan; Li, Haigang; Christie, Peter; Zhang, Fusuo; ZHANG, JUNLING

    2015-01-01

    The mechanistic understanding of the dynamic processes linking nutrient acquisition and biomass production of competing individuals can be instructive in optimizing intercropping systems. Here, we examine the effect of inoculation with Funneliformis mosseae on competitive dynamics between wheat and faba bean. Wheat is less responsive to mycorrhizal inoculation. Both inoculated and uninoculated wheat attained the maximum instantaneous N and P capture approximately five days before it attained ...

  20. Plasticity in N uptake among sympatric species with contrasting nutrient acquisition strategies in a tropical forest.

    Andersen, Kelly M; Mayor, Jordan R; Turner, Benjamin L

    2017-03-06

    Nitrogen (N) availability influences the productivity and distribution of plants in tropical montane forests. Strategies to acquire soil N, such as direct uptake of organic compounds or associations with root symbionts to enhance N acquisition in exchange for carbon (C), may facilitate plant species coexistence and ecosystem N retention. Alternatively, rapid microbial turnover of soil N forms in tropical soils might promote flexible plant N-uptake strategies and mediate species coexistence. We tested whether sympatric plant species with divergent root symbiont associations, and therefore potentially different nutrient acquisition strategies, partition chemical forms of N or show plasticity in N uptake in a tropical pre-montane forest in Panama. We traced the movement of three (15) N forms into soil pools, microbes, and seedlings of eleven species differing in root traits. Seedlings were grown in a split-plot field transplant experiment, with plots receiving equimolar mixtures of ammonium, nitrate, and glycine, with one form isotopically labeled in each block. After 48-hours, more (15) N was recovered in microbes than in plants, while all pools (extractable organic and inorganic N, microbial biomass, and leaves) contained greater amounts of (15) N from nitrate than from ammonium or glycine. Furthermore, (13) C from dual-labeled glycine was not recovered in the leaves of any seedlings, suggesting the studied species do not directly take up organic N or transform organic N prior to translocation to leaves. Nitrogen uptake differed by root symbiont group only for nitrate, with greater (15) N recovery in plants with arbuscular mycorrhizal (AM) associations or proteoid roots compared to orchids. Some root trait groups differed in (15) N recovery among N forms, with greater nitrate uptake than ammonium or glycine by AM-associated and N2 -fixing plants. However, only five of eleven species showed differences in uptake among N forms. Our results indicate flexibility in

  1. 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

    Accurate predictions of nutrient acquisition by plant roots and mycorrhizas are critical in modelling plant responses to climate change.We conducted a field experiment with the aim to investigate root nutrient uptake in a future climate and studied root production by ingrowth cores, mycorrhizal...... 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....... 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...

  2. 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.

  3. Ecoenzymatic Stoichiometry of Microbial Organic Nutrient Acquisition in Soil and Sediment

    Terrestrial soils and freshwater sediments contain reserves of organic carbon estimated at 1500 Pg and 0.2 Pg, respectively. Mineralization of this organic matter by heterotrophic microorganisms drives global carbon and nutrient cycles, controlling plant production and atmospher...

  4. 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

  5. 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.

  6. Enhancement of faba bean competitive ability by arbuscular mycorrhizal fungi is highly correlated with dynamic nutrient acquisition by competing wheat.

    Qiao, Xu; Bei, Shuikuan; Li, Chunjie; Dong, Yan; Li, Haigang; Christie, Peter; Zhang, Fusuo; Zhang, Junling

    2015-01-01

    The mechanistic understanding of the dynamic processes linking nutrient acquisition and biomass production of competing individuals can be instructive in optimizing intercropping systems. Here, we examine the effect of inoculation with Funneliformis mosseae on competitive dynamics between wheat and faba bean. Wheat is less responsive to mycorrhizal inoculation. Both inoculated and uninoculated wheat attained the maximum instantaneous N and P capture approximately five days before it attained the maximum instantaneous biomass production, indicating that wheat detected the competitor and responded physiologically to resource limitation prior to the biomass response. By contrast, the instantaneous N and P capture by uninoculated faba bean remained low throughout the growth period, and plant growth was not significantly affected by competing wheat. However, inoculation substantially enhanced biomass production and N and P acquisition of faba bean. The exudation of citrate and malate acids and acid phosphatase activity were greater in mycorrhizal than in uninoculated faba bean, and rhizosphere pH tended to decrease. We conclude that under N and P limiting conditions, temporal separation of N and P acquisition by competing plant species and enhancement of complementary resource use in the presence of AMF might be attributable to the competitive co-existence of faba bean and wheat.

  7. Nutrient acquisition, soil phosphorus partitioning and competition among trees in a lowland tropical rain forest.

    Nasto, Megan K; Osborne, Brooke B; Lekberg, Ylva; Asner, Gregory P; Balzotti, Christopher S; Porder, Stephen; Taylor, Philip G; Townsend, Alan R; Cleveland, Cory C

    2017-03-06

    We hypothesized that dinitrogen (N2 )- and non-N2 -fixing tropical trees would have distinct phosphorus (P) acquisition strategies allowing them to exploit different P sources, reducing competition. We measured root phosphatase activity and arbuscular mycorrhizal (AM) colonization among two N2 - and two non-N2 -fixing seedlings, and grew them alone and in competition with different inorganic and organic P forms to assess potential P partitioning. We found an inverse relationship between root phosphatase activity and AM colonization in field-collected seedlings, indicative of a trade-off in P acquisition strategies. This correlated with the predominantly exploited P sources in the seedling experiment: the N2 fixer with high N2 fixation and root phosphatase activity grew best on organic P, whereas the poor N2 fixer and the two non-N2 fixers with high AM colonization grew best on inorganic P. When grown in competition, however, AM colonization, root phosphatase activity and N2 fixation increased in the N2 fixers, allowing them to outcompete the non-N2 fixers regardless of P source. Our results indicate that some tropical trees have the capacity to partition soil P, but this does not eliminate interspecific competition. Rather, enhanced P and N acquisition strategies may increase the competitive ability of N2 fixers relative to non-N2 fixers.

  8. [Effects of biochar on soil nutrients leaching and potential mechanisms: A review].

    Liu, Yu-xue; Lyu, Hao-hao; Shi, Yan; Wang, Yao-feng; Zhong, Zhe-ke; Yang, Sheng-mao

    2015-01-01

    Controlling soil nutrient leaching in farmland ecosystems has been a hotspot in the research field of agricultural environment. Biochar has its unique physical and chemical properties, playing a significant role in enhancing soil carbon storage, improving soil quality and increasing crop yield. As a kind of new exogenous material, biochar has the potential in impacting soil nutrient cycling directly or indirectly, and has profound influences on soil nutrient leaching. This paper analyzed the intrinsic factors affecting how biochar affects soil nutrient leaching, such as the physical and chemical properties of biochar, and the interaction between biochar and soil organisms. Then the latest literatures regarding the external factors, including biochar application rates, soil types, depth of soil layer, fertilization conditions and temporal dynamics, through which biochar influences soil nutrient (especially nitrogen and phosphorus) leaching were reviewed. On that basis, four related action mechanisms were clarified, including direct adsorption of nutrients by biochar due to its micropore structure or surface charge, influencing nutrient leaching through increasing soil water- holding capacity, influencing nutrient cycling through the interaction with soil microbes, and preferential transport of absorbed nutrients by fine biochar particles. At last future research directions for better understanding the interactions between biochar and nutrient leaching in the soil were proposed.

  9. 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.

  10. Nutrients and hydrology indicate the driving mechanisms of peatland surface patterning.

    Eppinga, Maarten B; de Ruiter, Peter C; Wassen, Martin J; Rietkerk, Max

    2009-06-01

    Peatland surface patterning motivates studies that identify underlying structuring mechanisms. Theoretical studies so far suggest that different mechanisms may drive similar types of patterning. The long time span associated with peatland surface pattern formation, however, limits possibilities for empirically testing model predictions by field manipulations. Here, we present a model that describes spatial interactions between vegetation, nutrients, hydrology, and peat. We used this model to study pattern formation as driven by three different mechanisms: peat accumulation, water ponding, and nutrient accumulation. By on-and-off switching of each mechanism, we created a full-factorial design to see how these mechanisms affected surface patterning (pattern of vegetation and peat height) and underlying patterns in nutrients and hydrology. Results revealed that different combinations of structuring mechanisms lead to similar types of peatland surface patterning but contrasting underlying patterns in nutrients and hydrology. These contrasting underlying patterns suggest that the presence or absence of the structuring mechanisms can be identified by relatively simple short-term field measurements of nutrients and hydrology, meaning that longer-term field manipulations can be circumvented. Therefore, this study provides promising avenues for future empirical studies on peatland patterning.

  11. 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

  12. 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.

  13. Arbuscular mycorrhiza and water and nutrient supply differently impact seedling performance of dry woodland species with different acquisition strategies

    Emiru Birhane, E.B.; Kuyper, T.W.; Sterck, F.J.; Gebrehiwot, K.; Bongers, F.

    2015-01-01

    Background: Arbuscular mycorrhizal (AM) fungi increase seedling survival and performance through enhancement of nutrient and water uptake under stress conditions. Acacia etbaica, A. senegal and Boswellia papyrifera dominate large areas in African drylands where both moisture and nutrients are limite

  14. 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.

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

    Byler, Kristen A; Carmi-Veal, Maya; Fine, Maoz; Goulet, Tamar L

    2013-01-01

    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.

  16. 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.

  17. Reconciling genetic evolution and the associative learning account of mirror neurons through data-acquisition mechanisms.

    Lotem, Arnon; Kolodny, Oren

    2014-04-01

    An associative learning account of mirror neurons should not preclude genetic evolution of its underlying mechanisms. On the contrary, an associative learning framework for cognitive development should seek heritable variation in the learning rules and in the data-acquisition mechanisms that construct associative networks, demonstrating how small genetic modifications of associative elements can give rise to the evolution of complex cognition.

  18. 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.

  19. 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.

  20. Nutrient Acquisition and Generation of Reactive Oxygen Species Via CREA, AREA, and NOXa are Important in Pathogenicity in Mycosphaerella Graminicola

    Mycosphaerella graminicola is an important wheat pathogen causing significant economic loss. M. graminicola is a hemibiotroph, indicating that a biotrophic stage with nutrient uptake and a necrotrophic stage associated with a possible toxin or reactive oxygen species (ROS) are important to pathogeni...

  1. Defining planktonic protist functional groups on mechanisms for energy and nutrient acquisition

    Mitra, Aditee; Flynn, Kevin J.; Tillmann, Urban

    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...... for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope...

  2. Effect of Cooperative Learning on the Acquisition of Second Language Rules and Mechanics.

    Ghaith, G. M.; Yaghi, H. M.

    1998-01-01

    Examined the effect of cooperative learning on Lebanese elementary students' acquisition of English-as-a-Second-Language rules and mechanics. Pretest and posttest comparison of experimental and control classes did not significantly favor cooperative learning as compared to individualistic instruction, though low achieving experimental class…

  3. Convergence of a specialized root trait in plants from nutrient-impoverished soils: phosphorus-acquisition strategy in a nonmycorrhizal cactus.

    Abrahão, A; Lambers, H; Sawaya, A C H F; Mazzafera, P; Oliveira, R S

    2014-10-01

    In old, phosphorus (P)-impoverished habitats, root specializations such as cluster roots efficiently mobilize and acquire P by releasing large amounts of carboxylates in the rhizosphere. These specialized roots are rarely mycorrhizal. We investigated whether Discocactus placentiformis (Cactaceae), a common species in nutrient-poor campos rupestres over white sands, operates in the same way as other root specializations. Discocactus placentiformis showed no mycorrhizal colonization, but exhibited a sand-binding root specialization with rhizosheath formation. We first provide circumstantial evidence for carboxylate exudation in field material, based on its very high shoot manganese (Mn) concentrations, and then firm evidence, based on exudate analysis. We identified predominantly oxalic acid, but also malic, citric, lactic, succinic, fumaric, and malonic acids. When grown in nutrient solution with P concentrations ranging from 0 to 100 μM, we observed an increase in total carboxylate exudation with decreasing P supply, showing that P deficiency stimulated carboxylate release. Additionally, we tested P solubilization by citric, malic and oxalic acids, and found that they solubilized P from the strongly P-sorbing soil in its native habitat, when the acids were added in combination and in relatively low concentrations. We conclude that the sand-binding root specialization in this nonmycorrhizal cactus functions similar to that of cluster roots, which efficiently enhance P acquisition in other habitats with very low P availability.

  4. 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

  5. Research on Compensation Mechanism of Land Acquisition in Rural Areas Based on the Practice of Anhui Province

    Huixian ZHOU; Zhongxiang YU

    2016-01-01

    With the continuous development of Chinese economy and rapid progress it has made,land demand for urban construction becomes larger and larger. Rural urbanization has a great relation to common prosperity and plays a key role in realizing the 21 st century great dream of Chinese people of all ethnic groups. Because of the complicated situation of land acquisition and compensation mechanism,we will conduct a systematic analysis on the compensation mechanism of land acquisition in Anhui Province and put forward the compensation methods to perfect the compensation mechanism according to the present compensation mechanism and the existing shortages of land acquisition in Anhui Province.

  6. From aquatic to terrestrial life: evolution of the mechanisms for water acquisition.

    Takei, Yoshio

    2015-01-01

    It is generally accepted that ancient fishes first experienced freshwater (FW), and then variably by lineage moved onto the land or re-entered the seas during evolution. As both land and sea are desiccating environments, animals must change their strategies for body fluid regulation from protecting against overhydration in FW to coping with dehydration in seawater (SW) or on land. The evolution of the mechanisms for acquisition of water surely must have accompanied these dramatic environmental changes. The major route for water acquisition is by oral drinking in terrestrial tetrapods (represented here by mammals) and in SW fishes (represented by teleosts as they are dehydrated in SW), but the regulation is contrasting between the two groups; mechanisms inducing thirst have developed in mammals, whereas inhibitory mechanisms are dominant in marine teleosts as observed in FW teleosts. Thus, the apparent difference was found not between hydrating and dehydrating habitat, but rather between terrestrial and aquatic habitats. This contrast is also reflected in regulatory hormones; dipsogenic hormones such as angiotensin II play pivotal roles in water homeostasis in mammals, whereas antidipsogenic hormones such as atrial natriuretic peptide are essential in teleosts. Imbibed water becomes body fluid only after absorption by the intestine, and there is a distinct difference in the mechanisms for water absorption between mammals and teleosts. Like regulation of drinking, we found that the inhibitory mechanisms are dominant for intestinal water absorption in teleosts. In the initial part of this short review, interesting differences in the body fluid regulation between mammals and teleosts are introduced, particularly with regard to water acquisition (drinking and intestinal absorption). Then an attempt was made to discuss the evolution of the mechanisms from the two perspectives; transitions from aquatic to terrestrial habitats and from hydrating (FW) to dehydrating (land

  7. 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...

  8. A simple nutrient-dependence mechanism for predicting the stoichiometry of marine ecosystems.

    Galbraith, Eric D; Martiny, Adam C

    2015-07-07

    It is widely recognized that the stoichiometry of nutrient elements in phytoplankton varies within the ocean. However, there are many conflicting mechanistic explanations for this variability, and it is often ignored in global biogeochemical models and carbon cycle simulations. Here we show that globally distributed particulate P:C varies as a linear function of ambient phosphate concentrations, whereas the N:C varies with ambient nitrate concentrations, but only when nitrate is most scarce. This observation is consistent with the adjustment of the phytoplankton community to local nutrient availability, with greater flexibility of phytoplankton P:C because P is a less abundant cellular component than N. This simple relationship is shown to predict the large-scale, long-term average composition of surface particles throughout large parts of the ocean remarkably well. The relationship implies that most of the observed variation in N:P actually arises from a greater plasticity in the cellular P:C content, relative to N:C, such that as overall macronutrient concentrations decrease, N:P rises. Although other mechanisms are certainly also relevant, this simple relationship can be applied as a first-order basis for predicting organic matter stoichiometry in large-scale biogeochemical models, as illustrated using a simple box model. The results show that including variable P:C makes atmospheric CO2 more sensitive to changes in low latitude export and ocean circulation than a fixed-stoichiometry model. In addition, variable P:C weakens the relationship between preformed phosphate and atmospheric CO2 while implying a more important role for the nitrogen cycle.

  9. 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

    2015-06-01

    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.

  10. Relative Roles of Soil Moisture, Nutrient Supply, Depth, and Mechanical Impedance in Determining Composition and Structure of Wisconsin Prairies.

    Wernerehl, Robert W; Givnish, Thomas J

    2015-01-01

    Ecologists have long classified Midwestern prairies based on compositional variation assumed to reflect local gradients in moisture availability. The best known classification is based on Curtis' continuum index (CI), calculated using the presence of indicator species thought centered on different portions of an underlying moisture gradient. Direct evidence of the extent to which CI reflects differences in moisture availability has been lacking, however. Many factors that increase moisture availability (e.g., soil depth, silt content) also increase nutrient supply and decrease soil mechanical impedance; the ecological effects of the last have rarely been considered in any ecosystem. Decreased soil mechanical impedance should increase the availability of soil moisture and nutrients by reducing the root costs of retrieving both. Here we assess the relative importance of soil moisture, nutrient supply, and mechanical impedance in determining prairie composition and structure. We used leaf δ13C of C3 plants as a measure of growing-season moisture availability, cation exchange capacity (CEC) x soil depth as a measure of mineral nutrient availability, and penetrometer data as a measure of soil mechanical impedance. Community composition and structure were assessed in 17 remnant prairies in Wisconsin which vary little in annual precipitation. Ordination and regression analyses showed that δ13C increased with CI toward "drier" sites, and decreased with soil depth and % silt content. Variation in δ13C among remnants was 2.0‰, comparable to that along continental gradients from ca. 500-1500 mm annual rainfall. As predicted, LAI and average leaf height increased significantly toward "wetter" sites. CI accounted for 54% of compositional variance but δ13C accounted for only 6.2%, despite the strong relationships of δ13C to CI and CI to composition. Compositional variation reflects soil fertility and mechanical impedance more than moisture availability. This study is the

  11. 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...

  12. [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.

  13. M2 pyruvate kinase provides a mechanism for nutrient sensing and regulation of cell proliferation.

    Morgan, Hugh P; O'Reilly, Francis J; Wear, Martin A; O'Neill, J Robert; Fothergill-Gilmore, Linda A; Hupp, Ted; Walkinshaw, Malcolm D

    2013-04-09

    We show that the M2 isoform of pyruvate kinase (M2PYK) exists in equilibrium between monomers and tetramers regulated by allosteric binding of naturally occurring small-molecule metabolites. Phenylalanine stabilizes an inactive T-state tetrameric conformer and inhibits M2PYK with an IC50 value of 0.24 mM, whereas thyroid hormone (triiodo-L-thyronine, T3) stabilizes an inactive monomeric form of M2PYK with an IC50 of 78 nM. The allosteric activator fructose-1,6-bisphosphate [F16BP, AC50 (concentration that gives 50% activation) of 7 μM] shifts the equilibrium to the tetrameric active R-state, which has a similar activity to that of the constitutively fully active isoform M1PYK. Proliferation assays using HCT-116 cells showed that addition of inhibitors phenylalanine and T3 both increased cell proliferation, whereas addition of the activator F16BP reduced proliferation. F16BP abrogates the inhibitory effect of both phenylalanine and T3, highlighting a dominant role of M2PYK allosteric activation in the regulation of cancer proliferation. X-ray structures show constitutively fully active M1PYK and F16BP-bound M2PYK in an R-state conformation with a lysine at the dimer-interface acting as a peg in a hole, locking the active tetramer conformation. Binding of phenylalanine in an allosteric pocket induces a 13° rotation of the protomers, destroying the peg-in-hole R-state interface. This distinct T-state tetramer is stabilized by flipped out Trp/Arg side chains that stack across the dimer interface. X-ray structures and biophysical binding data of M2PYK complexes explain how, at a molecular level, fluctuations in concentrations of amino acids, thyroid hormone, and glucose metabolites switch M2PYK on and off to provide the cell with a nutrient sensing and growth signaling mechanism.

  14. A Hierarchical of Security Situation Element Acquisition Mechanism in Wireless Sensor Network

    Li Fangwei

    2015-08-01

    Full Text Available In wireless sensor network, the processing ability of the sensor nodes is poor. And the security situational element acquisition is also a serious problem. Thus, this paper proposes a hierarchical framework of security situational elements acquisition mechanism. In this framework, support vector machine hyper sphere multi class algorithm is introduced as basic classifier. The method of attribute reduction uses non negative matrix factorization algorithm. The fuzzy classification algorithm used to initialize non negative matrix factorization, in order to avoid the local optimal which is caused by non negative matrix factorization random initialization. In the sink node classification rules and attribute reduction rules are formed by learning. The classification analyses respectively focus on the cluster head and sink node, which can reduce the requirement of the sensor node properties. Attribute reduction before the data transmission, which reduces communication consumption data transmission, improves the performance of classifiers. By simulation analysis, the scheme has preferably accuracy in the situation elements acquisiton, and smaller communication overhead in the process of information transmission.

  15. The acquisition of prepositions in Serbian: Factors and mechanisms of development

    Savić Maja

    2004-01-01

    Full Text Available The study proceeds from the results of the previous studies showing that the distributional characteristics (frequency of language input are crucial for the acquisition of prepositions (Savić & Anđelković, 2005, in preparation. The authors analyze deviations in the distribution of prepositions in children's spontaneous speech from the prediction made on the basis of the distributional characteristics of prepositions in adult language. The results show that, in comparison with adult language, only the prepositions "kod" (at, by, near, beside and "sa" (with, from, off deviate from the prediction. It was also found out that the unexpectedly early and frequent use of the preposition "kod" in child speech stemmed from the frequent use of this preposition in child-directed speech. On the other hand, the preposition "sa", which is very frequent in child-directed speech, is not present in children's production at the earliest age, because its homonymy makes it cognitively complex. The analysis of the reasons for such a deviation provided a basis for the discussion about the possible factors and mechanisms of development: the distributional characteristics of adult language are the major factor of acquisition, but the effects of conceptual and structural complexity were recorded as well.

  16. 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.

  17. Mechanisms for success after long-term nutrient enrichment in a boreal forest understory.

    Tess Nahanni Grainger

    Full Text Available Global levels of reactive nitrogen are predicted to rise in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Many plant communities respond strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that was initiated in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer added annually on a boreal forest understory community. We used this experiment to investigate why some species increase in abundance under nutrient enrichment whereas others decline. We focused on four species that differed in their responses to fertilization: Mertensia paniculata and Epilobium angustifolium increased in abundance, Achillea millefolium remained relatively constant and Festuca altaica declined. We hypothesized that the two species that were successful in the new high-nutrient, light-limited environment would be taller, have higher specific leaf area, change phenology by growing earlier in the season and be more morphologically plastic than their less successful counterparts. We compared plant height, specific leaf area, growth spurt date and allocation to leaves in plants grown in control and fertilized plots. We demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; M. paniculata has the highest specific leaf area of the four species whereas E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaves. These results indicate that rather than one strategy determining success when nutrients become available, a variety of traits and responses may contribute to a species' ability to persist in a nutrient-enriched boreal forest

  18. Mechanisms for success after long-term nutrient enrichment in a boreal forest understory.

    Grainger, Tess Nahanni; Turkington, Roy

    2013-01-01

    Global levels of reactive nitrogen are predicted to rise in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Many plant communities respond strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that was initiated in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer added annually) on a boreal forest understory community. We used this experiment to investigate why some species increase in abundance under nutrient enrichment whereas others decline. We focused on four species that differed in their responses to fertilization: Mertensia paniculata and Epilobium angustifolium increased in abundance, Achillea millefolium remained relatively constant and Festuca altaica declined. We hypothesized that the two species that were successful in the new high-nutrient, light-limited environment would be taller, have higher specific leaf area, change phenology by growing earlier in the season and be more morphologically plastic than their less successful counterparts. We compared plant height, specific leaf area, growth spurt date and allocation to leaves in plants grown in control and fertilized plots. We demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; M. paniculata has the highest specific leaf area of the four species whereas E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaves. These results indicate that rather than one strategy determining success when nutrients become available, a variety of traits and responses may contribute to a species' ability to persist in a nutrient-enriched boreal forest understory.

  19. Effect of the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum on the essential oil yield related characters and nutrient acquisition in the crops of different cultivars of menthol mint (Mentha arvensis) under field conditions.

    Gupta, M L; Prasad, Arun; Ram, Muni; Kumar, Sushil

    2002-01-01

    The effects of inoculation with vesicular-arbuscular mycorrhizal (VAM) fungus Glomusfasciculatum on the root colonization, growth, essential oil yield and nutrient acquisition of three cultivars of menthol mint (Mentha arvensis); Kalka, Shivalik and Gomti, were studied under field conditions. The VAM inoculation significantly increased the root colonization, plant height, fresh herbage and dry matter yield. oil content and oil yield as compared to non-inoculated cultivars. The effect of VAM inoculation on the root colonization, growth and yield of mint was more pronounced with the cv Shivalik than the cvs Kalka and Gomati, indicating Shivalik as a highly mycorrhizal dependent genotype. VAM inoculation significantly increased the uptake of N, P and K by shoot tissues of mint, but most markedly increased the uptake of P. The VAM-inoculated mint plants depleted the available N, P and K in the rhizosphere soil as compared to non-inoculated control plants, however the extent of nutrient depletion was greater for P than N and K. We conclude that the VAM inoculation could significantly increase the root colonization, growth, essential oil yield and nutrient acquisition of mint for obtaining economic production under field conditions.

  20. Different Mechanisms Confer Gradual Control and Memory at Nutrient- and Stress-Regulated Genes in Yeast

    Rienzo, Alessandro; Poveda-Huertes, Daniel; Aydin, Selcan; Buchler, Nicolas E.; Pascual-Ahuir, Amparo; Proft, Markus

    2015-01-01

    Cells respond to environmental stimuli by fine-tuned regulation of gene expression. Here we investigated the dose-dependent modulation of gene expression at high temporal resolution in response to nutrient and stress signals in yeast. The GAL1 activity in cell populations is modulated in a well-defined range of galactose concentrations, correlating with a dynamic change of histone remodeling and RNA polymerase II (RNAPII) association. This behavior is the result of a heterogeneous induction d...

  1. 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.

  2. Specific Roles for 17ß-Estradiol versus Gonad Development in Nutrient Partitioning and Regulation of Nutrient- and Growth-Related Mechanisms During Sexual Maturation in Rainbow Trout

    The contribution of sex steroids to nutrient partitioning and energy balance during gonad development was studied in rainbow trout (Oncorhynchus mykiss). Nineteen month old triploid (3N) female rainbow trout were fed a diet supplemented with 17ß-estradiol (E2) at 30 mg steroid/kg diet for a 1 month...

  3. 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...

  4. Flow pathways and nutrient transport mechanisms drive hydrochemical sensitivity to climate change across catchments with different geology and topography

    J. Crossman

    2014-07-01

    Full Text Available Hydrological processes determine the transport of nutrients and passage of diffuse pollution. Consequently, catchments are likely to exhibit individual hydrochemical responses (sensitivities to climate change, which is expected to alter the timing and amount of runoff, and to impact in-stream water quality. In developing robust catchment management strategies and quantifying plausible future hydrochemical conditions it is therefore equally important to consider the potential for spatial variability in, and causal factors of, catchment sensitivity, as to explore future changes in climatic pressures. This study seeks to identify those factors which influence hydrochemical sensitivity to climate change. A perturbed physics ensemble (PPE, derived from a series of Global Climate Model (GCM variants with specific climate sensitivities was used to project future climate change and uncertainty. Using the Integrated Catchment Model of Phosphorus Dynamics (INCA-P, we quantified potential hydrochemical responses in four neighbouring catchments (with similar land use but varying topographic and geological characteristics in southern Ontario, Canada. Responses were assessed by comparing a 30 year baseline (1968–1997 to two future periods: 2020–2049 and 2060–2089. Although projected climate change and uncertainties were similar across these catchments, hydrochemical responses (sensitivity were highly varied. Sensitivity was governed by soil type (influencing flow pathways and nutrient transport mechanisms. Clay-rich catchments were most sensitive, with total phosphorus (TP being rapidly transported to rivers via overland flow. In these catchments large annual reductions in TP loads were projected. Sensitivity in the other two catchments, dominated by sandy-loams, was lower due to a larger proportion of soil matrix flow, longer soil water residence times and seasonal variability in soil-P saturation. Here smaller changes in TP loads, predominantly

  5. Runoff characteristics and nutrient loss mechanism from plain farmland under simulated rainfall conditions.

    Liu, Ruimin; Wang, Jiawei; Shi, Jianhan; Chen, Yaxin; Sun, Chengchun; Zhang, Peipei; Shen, Zhenyao

    2014-01-15

    In recent years, nonpoint source (NPS) pollution has become the main contributor to water quality problems. Research on nitrogen (N) and phosphorus (P) losses from farmland and the factors that influence these losses is very meaningful both for increasing the crop yield and for improving environmental water quality. To explore the mechanism by which N and P are lost from farmland in the North China Plain (NCP), 16 simulated rainfalls were conducted in 14 experimental fields (each of which had different conditions) in the NCP from July to August in 2010. The results showed that the rainfall intensity, the antecedent soil moisture content, and the vegetation cover status were the main factors that affected the surface runoff in the NCP. The runoff volume increased with the increasing rainfall intensity and the increasing soil moisture content, and decreased with the increasing vegetation cover. These factors also significantly affected the losses of P and N. The losses of P and N were positively correlated with the rainfall intensity and the antecedent soil moisture content, and negatively correlated with the vegetation cover. A longer and more intense rainfall resulted in a higher loss of N and P. Dissolved nitrogen was the predominant form of N loss. For phosphorous, the predominant loss form was greatly influenced by the rainfall intensity, the vegetation cover, and the antecedent soil moisture content. Most of phosphorus existed as dissolved phosphorus in Baizhuang (BZ) and as particulate phosphorus in Tangcheng (TC) and Fentai (FT). The minimum requirements for runoff occurrence in experimental regions were a rainfall depth of 5.1mm, a rainfall intensity of 50mm/h, and an antecedent soil moisture of approximately 29.6%.

  6. Shigella Iron Acquisition Systems and their Regulation.

    Wei, Yahan; Murphy, Erin R

    2016-01-01

    Survival of Shigella within the host is strictly dependent on the ability of the pathogen to acquire essential nutrients, such as iron. As an innate immune defense against invading pathogens, the level of bio-available iron within the human host is maintained at exceeding low levels, by sequestration of the element within heme and other host iron-binding compounds. In response to sequestration mediated iron limitation, Shigella produce multiple iron-uptake systems that each function to facilitate the utilization of a specific host-associated source of nutrient iron. As a mechanism to balance the essential need for iron and the toxicity of the element when in excess, the production of bacterial iron acquisition systems is tightly regulated by a variety of molecular mechanisms. This review summarizes the current state of knowledge on the iron-uptake systems produced by Shigella species, their distribution within the genus, and the molecular mechanisms that regulate their production.

  7. Drug-nutrient interactions.

    Chan, Lingtak-Neander

    2013-07-01

    Drug-nutrient interactions are defined as physical, chemical, physiologic, or pathophysiologic relationships between a drug and a nutrient. The causes of most clinically significant drug-nutrient interactions are usually multifactorial. Failure to identify and properly manage drug-nutrient interactions can lead to very serious consequences and have a negative impact on patient outcomes. Nevertheless, with thorough review and assessment of the patient's history and treatment regimens and a carefully executed management strategy, adverse events associated with drug-nutrient interactions can be prevented. Based on the physiologic sequence of events after a drug or a nutrient has entered the body and the mechanism of interactions, drug-nutrient interactions can be categorized into 4 main types. Each type of interaction can be managed using similar strategies. The existing data that guide the clinical management of most drug-nutrient interactions are mostly anecdotal experience, uncontrolled observations, and opinions, whereas the science in understanding the mechanism of drug-nutrient interactions remains limited. The challenge for researchers and clinicians is to increase both basic and higher level clinical research in this field to bridge the gap between the science and practice. The research should aim to establish a better understanding of the function, regulation, and substrate specificity of the nutrient-related enzymes and transport proteins present in the gastrointestinal tract, as well as assess how the incidence and management of drug-nutrient interactions can be affected by sex, ethnicity, environmental factors, and genetic polymorphisms. This knowledge can help us develop a true personalized medicine approach in the prevention and management of drug-nutrient interactions.

  8. 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.

  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. Flavor-nutrient learning is less rapid with fat than with carbohydrate in rats.

    Revelle, Christina Humphries; Warwick, Zoe S

    2009-06-22

    Flavor-nutrient learning occurs when the post-ingestive consequences of a food are associated with its flavor. As a signal of the food's energy density, flavor-nutrient associations have the potential to contribute to the regulation of meal size. While all calorie sources (fat, carbohydrate, protein, ethanol) can support flavor-nutrient learning, prior research has found that flavor-nutrient associations based on fat may require higher nutrient concentrations and more rigorous experimental protocols than are required to train carbohydrate (cho)-based associations. To further explore potential macronutrient-specific differences in flavor-nutrient learning, the present study compared the time course of acquisition of cho- and fat-based associations. Rats were trained to associate distinctive flavors with high-density (3.2 kcal/mL) and low-density (0.2 kcal/mL) orally-consumed solutions, either fat (corn oil emulsion) or carbohydrate (sucrose). For each nutrient, both within- and between-group designs were used to assess (via two-bottle preference testing) whether flavor-nutrient learning had occurred after 2, 4, or 6 training trial pairs. Rats trained with carbohydrate demonstrated preferential intake of the low-density paired flavor after only 2 training pairs; in contrast, rats trained with fat required 6 training pairs. These findings demonstrate differential rapidity of acquisition flavor-nutrient associations. The longer time course of acquisition of fat-based flavor-nutrient associations may be yet another mechanism by which high-fat foods promote overeating.

  11. 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.

  12. 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.

  13. Acquisition of an Instron Electropuls E3000 Instrument for Mechanical Testing

    2015-04-17

    determine the strain response of collagen in the form of Type I fascicles obtained from rat - tail tendons under dynamic loading conditions. A... rat - tail tendons have been done under load control (0.4 ± 0.3 N) at 0.5, 1, 2.5 and 5 Hz (see Fig. 3...I collagen fascicles under cyclic loading; P. Sundaram (Department of Mechanical Engineering). 7. Factors Influencing Formation or Inhibition of

  14. Mechanisms Involved in Acquisition of blaNDM Genes by IncA/C2 and IncFIIY Plasmids.

    Wailan, Alexander M; Sidjabat, Hanna E; Yam, Wan Keat; Alikhan, Nabil-Fareed; Petty, Nicola K; Sartor, Anna L; Williamson, Deborah A; Forde, Brian M; Schembri, Mark A; Beatson, Scott A; Paterson, David L; Walsh, Timothy R; Partridge, Sally R

    2016-07-01

    blaNDM genes confer carbapenem resistance and have been identified on transferable plasmids belonging to different incompatibility (Inc) groups. Here we present the complete sequences of four plasmids carrying a blaNDM gene, pKP1-NDM-1, pEC2-NDM-3, pECL3-NDM-1, and pEC4-NDM-6, from four clinical samples originating from four different patients. Different plasmids carry segments that align to different parts of the blaNDM region found on Acinetobacter plasmids. pKP1-NDM-1 and pEC2-NDM-3, from Klebsiella pneumoniae and Escherichia coli, respectively, were identified as type 1 IncA/C2 plasmids with almost identical backbones. Different regions carrying blaNDM are inserted in different locations in the antibiotic resistance island known as ARI-A, and ISCR1 may have been involved in the acquisition of blaNDM-3 by pEC2-NDM-3. pECL3-NDM-1 and pEC4-NDM-6, from Enterobacter cloacae and E. coli, respectively, have similar IncFIIY backbones, but different regions carrying blaNDM are found in different locations. Tn3-derived inverted-repeat transposable elements (TIME) appear to have been involved in the acquisition of blaNDM-6 by pEC4-NDM-6 and the rmtC 16S rRNA methylase gene by IncFIIY plasmids. Characterization of these plasmids further demonstrates that even very closely related plasmids may have acquired blaNDM genes by different mechanisms. These findings also illustrate the complex relationships between antimicrobial resistance genes, transposable elements, and plasmids and provide insights into the possible routes for transmission of blaNDM genes among species of the Enterobacteriaceae family.

  15. Mechanism of Children's Language Acquisition%儿童语言获得机制的研究

    刘晓峰

    2012-01-01

    语言是儿童生长过程中掌握的最复杂的符号系统,语言的发展几乎影响到儿童发展的所有方面。多年来,心理学家和语言学家们对儿童语言获得这一问题进行了持续的研究,从不同的角度试图解释儿童语言的获得。先后形成了经典条件作用范式观点、操作条件作用范式观点、认知发展的观点、普遍性观点、成熟观点、"先天论"的观点、精进或调谐理论等研究成果,而从人类进化的宏观视角阐述与分析儿童语言获得机制又给我们提供了一种新的方法论。%Language is the childreng growth process of mastering the most complex system of signs, language development, affecting vir- tually all aspects of child development. Over the years, psychologists and linguists on the issue of child language were sustained re- search, from different perspectives trying to explain child language acquisition. Has formed a classical conditioning paradigm point of view, the role of operating conditions paradigm point of view, cognitive development point of view, universal point of view, mature point of view, "nativism" point of view, streamlining or tuning theory research, macro - evolution from human Theoretical Perspective and analysis of child language acquisition mechanism gave us a new methodology.

  16. Mechanism of acquisition of chromosomal markers by plasmids in Haemophilus influenzae

    Setlow, J.K.; Cabrera-Juarez, E.; Griffin, K.

    1984-11-01

    The hybrid plasmid pNov1 readily acquired genetic information from the chromosome of wild-type, but not rec-2, cells. Most of the recombination had taken place 1 h after entrance of the plasmid into the cell, as judged by transformation of rec-2 by lysates made from wild-type cells exposed to pNova. Measurement of physical transfer from radioactively labeled cellular DNA to plasmids recombining in wild-type cells failed, since there was little more radioactivity in plasmids from such cells than from labeled rec-2 recipients, in which no recombination took place. EcoRI digestion of pNov1 divided the DNA into a 1.7-kilobase-pair fragment containing the novobiocin resistance marker and a 13-kilobase-pair fragment containing all of the original vector and considerable portions homologous to the chromosome. Transformation by the large fragment alone resulted in a plasmid the size of the original pNov1. The hypothesis to explain the data is that genetic transfer from chromosome to plasmid took place by a copy choice mechanism.

  17. Applying Aspects of the Expert Performance Approach to Better Understand the Structure of Skill and Mechanisms of Skill Acquisition in Video Games.

    Boot, Walter R; Sumner, Anna; Towne, Tyler J; Rodriguez, Paola; Anders Ericsson, K

    2016-11-20

    Video games are ideal platforms for the study of skill acquisition for a variety of reasons. However, our understanding of the development of skill and the cognitive representations that support skilled performance can be limited by a focus on game scores. We present an alternative approach to the study of skill acquisition in video games based on the tools of the Expert Performance Approach. Our investigation was motivated by a detailed analysis of the behaviors responsible for the superior performance of one of the highest scoring players of the video game Space Fortress (Towne, Boot, & Ericsson, ). This analysis revealed how certain behaviors contributed to his exceptional performance. In this study, we recruited a participant for a similar training regimen, but we collected concurrent and retrospective verbal protocol data throughout training. Protocol analysis revealed insights into strategies, errors, mental representations, and shifting game priorities. We argue that these insights into the developing representations that guided skilled performance could only easily have been derived from the tools of the Expert Performance Approach. We propose that the described approach could be applied to understand performance and skill acquisition in many different video games (and other short- to medium-term skill acquisition paradigms) and help reveal mechanisms of transfer from gameplay to other measures of laboratory and real-world performance.

  18. Pharmacological mechanisms and effects of amino acid nutrients%氨基酸型营养素药理学机制及作用

    田锋; 王新颖

    2013-01-01

    氨基酸型营养素不仅参与合成机体蛋白质,还调节患者免疫功能和代谢.氨基酸型营养素包括:谷氨酰胺,能改善肠屏障功能,减轻炎性反应,促进免疫功能恢复,但不同疾病的临床应用仍无一致结论;精氨酸,两种代谢方式相互竞争,对不同疾病具体影响仍需进一步研究;亮氨酸,主要促进肌肉蛋白质合成,对代谢的影响尚存争议;蛋氨酸和半胱氨酸,能促进伤口愈合,对脂质代谢的益处正受重视.本综述回顾上述氨基酸型营养素对机体作用的有益生理机制及其临床应用,并简单介绍不同营养素间及营养素同机体的相互影响.%Common amino acid nutrients mainly contain glutamine,arginine,leucine,methionine and cysteine,which are not only the components participating in body protein synthesis,but also regulate the patients' immune system and metabolism.Glutamine can improve the intestinal barrier,reduce inflammatory reaction,and promote immunity recovery,but the clinical effects of different patients with different diseases are still lack of clear conclusions.The catabolism of arginine can produce NO,promoting the inflammatory reaction,and can also generate omithine,alleviating inflammatory reaction and promoting wound healing.Two competing ways coexist,but the specific effects on different diseases have no clear conclusions yet.Leucine promotes muscle protein synthesis mainly through mTOR pathway,however,the influence on metabolism is still debating.Sulfurcontaining amino acids methionine and cysteine can promote the synthesis of connective tissue and collagen conducive to wound healing,and their beneficial effects on lipid metabolism are of value.The purpose of this review is to cover potential beneficial physiological mechanisms of amino acid nutrients,to describe their results of clinical applications and to evaluate the interactions among individual nutrients or between individual nutrients and body.

  19. 间套作改善作物矿质营养的机理研究进展%Advances in the mechanism of improving crop mineral nutrients in intercropping and relay intercropping systems

    付学鹏; 吴凤芝; 吴瑕; 刘丹

    2016-01-01

    [Objectives]Crop mineral nutrients can be improved in intercropping and relay intercropping systems. In recent years, productivity of crops has been investigated, and the mechanism of efficient utilization of mineral nutrients in intercropping and relay intercropping systems has been focused on.Dynamics of rhizosphere mineral nutrients contents and crop mineral nutrient acquisition in intercropping or relay intercropping systems were summarized in this paper.[Major advances]1 ) The ammonium nitrogen and amino acid nitrogen in the root exudates of crops is the nitrogen sources for the adjacent crops, and the nitrogen fixation of leguminous crops is enhanced attributing to the induction of root exudates, so as to increasing nitrogen nutrient content in rhizosphere. 2) Organic acids in root exudates can mobilize insoluble phosphorus, iron and potassium in the rhizosphere, and enhance the availabilities of mineral nutrients for crops.3) Root architecture and gene expression related to mineral nutrients uptakes are changed in intercropping or relay intercropping.The changes may be mediated by root exudates or above-ground interspecific interactions.The below-ground niche complementarity and enhanced gene expression may contribute to the efficient utilization of mineral nutrients.4 ) The arbuscular mycorrhizal which would potentially create networks originating from crops by means of hyphal anastomoses is facilitative for the nutrition transfer among crops.5 ) Soil biodiversity ( soil fauna and microbes ) which positively contributes to nutrients uptakes can be influenced by intercropping and relay intercropping.Some specific function microbes such as phosphorus-solubilizing bacteria are attracted and accumulated in the rhizosphere as a result of variation of microbes metabolism, thus increasing the mineral nutrients bioavailability.6) The soil enzyme activities ( such as urease, acid phosphatase and alkaline phosphatase) are increased in intercropping and relay

  20. Effects of Nitroglycerine on erythrocyte Rheology:A Novel Mechanism to Explain the Enhancement of Nutrient Blood Flow to Ischemic Zones

    2007-01-01

    Nitroglycerine (NTG) enhances coronary blood flow to compromised myocardium is important in relieving ischemia. However, the mechanism for this increase in myocardial blood flow (MBF) is not well defined. In small vessels and capillaries, relative blood viscosity plays a very important role in determining myocardial vascular resistance (MVR). MVR reduce is due partly to the increase in negative charge of erythrocyte surface. We therefore hypothesized that the enhancement of nutrient blood flow to zones of myocardial ischemia during NTG is partly secondary to reduced MVR and blood flow viscosity. The latter is affected by the negative charge of erythrocyte surface. Methods 6 dogs with LAD flow-limiting stenosis ( group 1 ) and 6 dogs with LAD flow-limiting stenosis and LCx occlusion(group 2) were studied. At baseline and during intracoronary infusions of NTG (0.3-0.6 μg · kg-1·min-1 ), hemodynamics, MBF (mL·min-1·g-1), whole blood viscosity (WBη, mPa. S), elongation index (EI), eletrophoretic mobility of erythocytes (EME, [ μ. S-1 )/(V. Cm-1 ) ] ) and percent wall thickening (% WT) were determined. MVR was calculated using driving pressure/MBF. Results As compared to baseline, no changes in hemodynamics were seen during NTG. MBF increased and MVR decreased significantly in normal bed, the central 25 % and the entire of stenosed bed (P < 0.05 ), with a decrease in WBη in both group 1 and group 2 dogs (18.6±9.7 % and 19.2±14.5 %, respectively). However, the % decrease in WBη was proportioned to the % increase in MBF or the % decrease in MVR only in the central 25% of stenosed bed ( r =0.87, P <0.001 ), but not in the entire stenosed bed and normal bed. EI did not show statistically significant differences between during NTG and at baseline, but EME did increase. And the % decrease in WBη during NTG was related to the % increase in EME ( r =0.83, P =0.01 ). Conclusions NTG reduced myocardial vascular resistance and blood viscosity due to the change of

  1. 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

  2. Mechanisms of inorganic carbon acquisition in two estuarine Rhodophyceans: Bostrychia scorpioides (Hudson) ex Kützing Montagne and Catenella caespitosa (Withering) L. M. Irvine.

    Ruiz-Nieto, Miriam; Fernández, José A; Niell, F Xavier; Carmona, Raquel

    2014-09-01

    Marine macroalgae possess a range of mechanisms to increase the availability of CO2 for fixation by ribulose-1,5-bisphosphate carboxylase/oxygenase. Of these, possession of a periplasmic or external carbonic anhydrase and the ability to use bicarbonate ions is widely distributed. The mechanisms of carbon acquisition were studied in two estuarine red macroalgae Bostrychia scorpioides and Catenella caespitosa using a range of techniques. pH-drift and CO2-depletion experiments at constant pH suggested that CO2 is the main source of inorganic carbon in both species. Inhibitors indicated that internal and external carbonic anhydrase were present in both species. Inhibitors also suggested that uptake of bicarbonate is unlikely to be present (P < 0.05).

  3. Early root overproduction not triggered by nutrients decisive for competitive success belowground.

    Francisco M Padilla

    Full Text Available BACKGROUND: Theory predicts that plant species win competition for a shared resource by more quickly preempting the resource in hotspots and by depleting resource levels to lower concentrations than its competitors. Competition in natural grasslands largely occurs belowground, but information regarding root interactions is limited, as molecular methods quantifying species abundance belowground have only recently become available. PRINCIPAL FINDINGS: In monoculture, the grass Festuca rubra had higher root densities and a faster rate of soil nitrate depletion than Plantago lanceolata, projecting the first as a better competitor for nutrients. However, Festuca lost in competition with Plantago. Plantago not only replaced the lower root mass of its competitor, but strongly overproduced roots: with only half of the plants in mixture than in monoculture, Plantago root densities in mixture were similar or higher than those in its monocultures. These responses occurred equally in a nutrient-rich and nutrient-poor soil layer, and commenced immediately at the start of the experiment when root densities were still low and soil nutrient concentrations high. CONCLUSIONS/SIGNIFICANCE: Our results suggest that species may achieve competitive superiority for nutrients by root growth stimulation prior to nutrient depletion, induced by the presence of a competitor species, rather than by a better ability to compete for nutrients per se. The root overproduction by which interspecific neighbors are suppressed independent of nutrient acquisition is consistent with predictions from game theory. Our results emphasize that root competition may be driven by other mechanisms than is currently assumed. The long-term consequences of these mechanisms for community dynamics are discussed.

  4. 羟基酪醇作为线粒体营养素的调控机制%The regulation mechanism of hydroxytyrosol as a mitochondrial nutrient

    罗成; 刘健康

    2012-01-01

    地中海饮食,特别是橄榄油,赋予了地中海周边国家人民对于退行性疾病的强力抵抗,尤其是心血管疾病和肿瘤的发生率以及致死率相对更低.羟基酪醇是橄榄油中的多酚类化合物之一,在防治紫外辐射、糖尿病、老年性视网膜黄斑病变、心血管疾病以及肿瘤等方面都具有重要的生物学效应.将具体阐述羟基酪醇作为一种线粒体营养素(如通过调节线粒体的动态变化以及Nrf2介导的抗氧化酶的诱导等)如何促进其有益功能.%Mediterranean diets, especially olive oil, play a vital role in resistance to degenerative diseases, particularly cardiovascular diseases and cancer, promoting a relatively lower incidence and mortality. As one of polyphenolic compounds in olive oil, hydroxytyrosol exhibits excellent biological effects on resistance to many diseases, such as UV radiation, diabetes, age-related macular disease, cardiovascular disease, and cancer, etc. This review will focus on the regulation mechanism of hydroxytyrosol as a mitochondrial nutrient through promoting mitochondrial dynamics and Nrf2-mediated antioxidant and detoxifying enzymes induction.

  5. 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

  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.

  7. Knowledge Transfers following Acquisition

    Gammelgaard, Jens

    2001-01-01

    Prior relations between the acquiring firm and the target company pave the way for knowledge transfers subsequent to the acquisitions. One major reason is that through the market-based relations the two actors build up mutual trust and simultaneously they learn how to communicate. An empirical...... 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...

  8. Nutrient cycling strategies.

    Breemen, van N.

    1995-01-01

    This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of their competitors. Higher or lower internal nutrient use efficiency positively feeds back into the nutrient cycle, and helps to increase or decrease soil fertili

  9. Lowbush blueberries, Vaccinium angustifolium, modulate the functional potential of nutrient utilization and DNA maintenance mechanisms in the rat proximal colon microbiota

    Alison Lacombe

    2012-06-01

    Full Text Available Background: The core gut microbiota encodes for a metabolic capacity that often surpasses the metabolic potential of its host. Lowbush wild blueberries (LWB are a rich source of bioactive compounds, and the gut microbiota is an important modulator of their activity. The objective of this research is to study the effect of a diet enriched with LWB on the gastrointestinal microbiota’s metabolic potential. Methods: Nine three-week-old male Sprague Dawley rats were randomly assigned to two groups. The control group (N=4 was placed on the AIN93 diet, and the treatment group (N=5 was fed the same diet with 8% (w/w LWB powder substituting for dextrose. The animals consumed the diets for six weeks, after which they were sacrificed. Functional profiles and metabolic potential of the colon microbiota in response to diet were analyzed using deep whole genome sequencing (WGS. Results: Proteins predicted from WGS DNA sequences were assigned to 3,746 COG, 5,577 KEGG, and 4,474 Pfam families. Statistical comparisons of the protein-coding genes revealed significant changes in 25 Gene Ontology (GO, 186 KEGG, and 20 Pfam protein families representing 2.1%, 3.3%, and 0.02% of all hits identified, respectively. Overall, the combined inquires into these databases represented an emphasis on membrane trafficking, DNA regulation, modification and repair, and nutrient metabolism. Protein families that significantly increased by the enrichment of LWBs were involved with amino acid metabolism, 2,4-dienoyl-CoA reductase, metal ion binding, glutamate synthase, REDOX homeostasis, and aryl transferases. In Functional Foods in Health and Disease 2012, 2(6:228-241 contrast, protein families involved with integrase/recombinase, reverse transcriptase, and transposon/transposase were at a lower abundance. Conclusions: The results from this study reflect the potential impact that LWBs have on the functional repertoire of bacterial communities in the proximal colon. The results

  10. 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 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.

  11. 机械产品专利作用结构知识提取方法研究%Acquisition Method for Principle Solution of Mechanical Patent

    薛驰; 邱清盈; 冯培恩; 邓坤

    2013-01-01

    机械产品专利包含了产品改进和创新的技术知识,对专利知识有效提取和合理表示是利用专利知识辅助产品创新的关键技术之一.分析了现有专利技术方案提取方法和知识表示所存在的问题,提出了针对英文专利包括技术对象和技术关系两方面提取任务的专利作用结构知识提取方法,建立了基于可扩展标记语言结构XSD表示和统一建模语言UML的专利作用结构知识表示模型.研究了机械产品专利语言的特点,采用最大熵原理和专利术语词典识别提取技术对象,通过建立组成类动词库识别核心动词提取技术关系.该专利作用结构知识表示模型具有表达直观和提取过程计算机自动处理等特点.结合专利实例,提出了从专利中提取专利作用结构知识,写入XSD结构化文档,最后转化为专利作用结构表示图的获取过程.%The problems of the existed acquisition method and representation method for patent technical solution were discussed. A new knowledge acquisition method for mechanical patent's principle solution including the acquisition task of technical object and technical relationship was proposed. Based on extensible markup language schema definition ( XSD) and unified modeling language ( UML) , the representation model of patent technical solution was built up. According to the characteristics of mechanical patent's text, technical object with the method of maximum entropy principle and patent term dictionary was acquired. The composition verb database was established and technical relationship was acquired. This method has some advantages such as the intuitionistic representation of the patent knowledge and the feature that the knowledge was automatically processed by computer. A whole process involved the steps like acquiring the principle knowledge from patent documents, writing the knowledge into XSD and transforming XSD to the representation model was illustrated with a

  12. Variation in nutrient resorption by desert shrubs

    Plant nutrient resorption prior to leaf senescence is an important nutrient conservation mechanism for aridland plant species. However, little is known regarding the phylogenetic and environmental factors influencing this trait. Our objective was to compare nitrogen and phosphorus resorption in a ...

  13. Mergers & Acquisitions

    Fomcenco, Alex

    and functioning of provisions of European federal corporate law and internationally accepted principles of the law of obligations. This book, however, is not about clarification of the reasons that urge for M&A operations, nor is it about judging the outcome of the transactions. It is about synthesizing......MERGERS & ACQUISITIONS: Counseling and Choice of Method describes and analyzes 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. The focus is aimed and maintained at application......, on the one hand, the methods of M&A and, on the other hand, several selected key elements. Any participating party - as well as their respective advisers - must be aware of these elements prior, throughout, and after the transaction: consideration, succession, taxes and fiscal neutrality, group...

  14. 生物质炭对土壤养分淋溶的影响及潜在机理研究进展%Effects of biochar on soil nutrients leaching and potential mechanisms: A review

    刘玉学; 吕豪豪; 石岩; 王耀锋; 钟哲科; 杨生茂

    2015-01-01

    soil nutrient (especially nitrogen and phosphorus) leaching were reviewed.On that basis,four related action mechanisms were clarified,including direct adsorption of nutrients by biochar due to its micropore structure or surface charge,influencing nutrient leaching through increasing soil waterholding capacity,influencing nutrient cycling through the interaction with soil microbes,and preferential transport of absorbed nutrients by fine biochar particles.At last future research directions for better understanding the interactions between biochar and nutrient leaching in the soil were pro-posed.

  15. 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.

  16. Improving crop nutrient efficiency through root architecture modifications

    Xinxin Li; Rensen Zeng; Hong Liao

    2016-01-01

    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.

  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.

  18. 75 FR 57690 - Acquisition Regulation: Sustainable Acquisition

    2010-09-22

    ... Parts 907, 923, 936, 952, and 970 RIN 1991-AB95 Acquisition Regulation: Sustainable Acquisition AGENCY... (DOE) is amending the Department of Energy Acquisition Regulation (DEAR) to implement Executive Order... to leverage agency acquisitions to foster markets for sustainable technologies and energy...

  19. Root morphology and mycorrhizal symbioses together shape nutrient foraging strategies of temperate trees.

    Chen, Weile; Koide, Roger T; Adams, Thomas S; DeForest, Jared L; Cheng, Lei; Eissenstat, David M

    2016-08-01

    Photosynthesis by leaves and acquisition of water and minerals by roots are required for plant growth, which is a key component of many ecosystem functions. Although the role of leaf functional traits in photosynthesis is generally well understood, the relationship of root functional traits to nutrient uptake is not. In particular, predictions of nutrient acquisition strategies from specific root traits are often vague. Roots of nearly all plants cooperate with mycorrhizal fungi in nutrient acquisition. Most tree species form symbioses with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EM) fungi. Nutrients are distributed heterogeneously in the soil, and nutrient-rich "hotspots" can be a key source for plants. Thus, predicting the foraging strategies that enable mycorrhizal root systems to exploit these hotspots can be critical to the understanding of plant nutrition and ecosystem carbon and nutrient cycling. Here, we show that in 13 sympatric temperate tree species, when nutrient availability is patchy, thinner root species alter their foraging to exploit patches, whereas thicker root species do not. Moreover, there appear to be two distinct pathways by which thinner root tree species enhance foraging in nutrient-rich patches: AM trees produce more roots, whereas EM trees produce more mycorrhizal fungal hyphae. Our results indicate that strategies of nutrient foraging are complementary among tree species with contrasting mycorrhiza types and root morphologies, and that predictable relationships between below-ground traits and nutrient acquisition emerge only when both roots and mycorrhizal fungi are considered together.

  20. 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...... the focus is aimed and maintained at application and functioning of provisions of European federal corporate law and internationally accepted principles of the law of obligations. This study, however, is not about clarification of the reasons that urge for M&A operations, nor is it about judging the results...... of the transactions. This study is about synthesizing, on the one hand, the methods of M&A, and, on the other hand, several selected key elements, which any participating party, as well as their respective advisers, must be aware of, prior, throughout, and after the transaction: consideration, succession, taxes...

  1. 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.

  2. 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...

  3. Defense Acquisition and the Case of the Joint Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a Mechanism for Adaptive Change

    2013-04-01

    provides for a rich and broad diversity of scholarly rigor mixed with a good blend of practitioner experience in the field of acquisition. We are...generated negative externalities, whereas industry transformation in Minnesota retained negative feedback brakes and avoided some of these effects

  4. Improving Acquisition Outcomes with Contextual Ambidexterity

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

    2015-01-01

    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...

  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 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...... transporters are also down-regulated within mycorrhizal roots by a mechanism not involving nutrient supply by the fungus. Carbon demand by the fungus may be one factor that can influence their expression within mycorrhizal roots....

  6. The Construction of Social Contradiction Dissolving Mechanism of Group Petition on Land-acquisition and Resident-resettlement%征地拆迁群访事件矛盾化解机制的构建

    柯楚将; 莫岳云

    2012-01-01

      The group petition on land-acquisition and resident-resettlement is a frequent social phenomenon in re -cent years.To build up unblocked channels for public interest expression and break the institutional barriers are the most urgent issues to dissolve the dilemma of frequent group petition on land -acquisition and resident-resettlement. This article brings the coping mechanism in three different stages according to the actual basis of group petition on land-acquisition and resident -resettlement, including the early warning mechanism before the event , the disposal and dissolving mechanism during the event and multiple -channel dissolving mechanism based on law after the e -vent, aiming to construct one long-time effective mechanism from the democratic and scientific views .%  征地拆迁群访事件是近年来频发的社会现象。疏通群众利益诉求渠道,破除体制性梗阻,是化解征地拆迁群访事件频发困局的当务之急。本文根据征地拆迁群访事件的实际,提出了事前、事中、事后三个不同阶段的应对机制,包括事前的预警机制、事中的处置和化解机制,以及事后以法律为核心的多渠道解决机制等,力图从民生和科学的角度构建行之有效的长效机制

  7. Mitochondria in response to nutrients and nutrient-sensitive pathways.

    Baltzer, Claudia; Tiefenböck, Stefanie K; Frei, Christian

    2010-11-01

    Mitochondria are abundant cellular organelles, and are required for the generation of energy through oxidative catabolism. Equally important, mitochondria also provide substrates for de novo synthesis of fatty acids and multiple amino acids. Mitochondrial functions must therefore be tightly linked to cellular nutrient availability. This review focuses on the current knowledge of how nutrients affect mitochondria. In particular, we describe how the transcriptional profile of the nucleus is altered to mediate this control, and the transcription factors that are involved. In addition, we summarize recent progress in our understanding of how transcription-independent mechanisms, most notably through the cellular energy sensor mTOR, are used to adapt mitochondrial functions in respect to cellular metabolic needs.

  8. First language acquisition.

    Goodluck, Helen

    2011-01-01

    This article reviews current approaches to first language acquisition, arguing in favor of the theory that attributes to the child an innate knowledge of universal grammar. Such knowledge can accommodate the systematic nature of children's non-adult linguistic behaviors. The relationships between performance devices (mechanisms for comprehension and production of speech), non-linguistic aspects of cognition, and child grammars are also discussed. WIREs Cogn Sci 2011 2 47-54 DOI: 10.1002/wcs.95 For further resources related to this article, please visit the WIREs website.

  9. Diagnosing oceanic nutrient deficiency

    Moore, C. Mark

    2016-11-01

    The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical-chemical-biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  10. Syntax acquisition.

    Crain, Stephen; Thornton, Rosalind

    2012-03-01

    Every normal child acquires a language in just a few years. By 3- or 4-years-old, children have effectively become adults in their abilities to produce and understand endlessly many sentences in a variety of conversational contexts. There are two alternative accounts of the course of children's language development. These different perspectives can be traced back to the nature versus nurture debate about how knowledge is acquired in any cognitive domain. One perspective dates back to Plato's dialog 'The Meno'. In this dialog, the protagonist, Socrates, demonstrates to Meno, an aristocrat in Ancient Greece, that a young slave knows more about geometry than he could have learned from experience. By extension, Plato's Problem refers to any gap between experience and knowledge. How children fill in the gap in the case of language continues to be the subject of much controversy in cognitive science. Any model of language acquisition must address three factors, inter alia: 1. The knowledge children accrue; 2. The input children receive (often called the primary linguistic data); 3. The nonlinguistic capacities of children to form and test generalizations based on the input. According to the famous linguist Noam Chomsky, the main task of linguistics is to explain how children bridge the gap-Chomsky calls it a 'chasm'-between what they come to know about language, and what they could have learned from experience, even given optimistic assumptions about their cognitive abilities. Proponents of the alternative 'nurture' approach accuse nativists like Chomsky of overestimating the complexity of what children learn, underestimating the data children have to work with, and manifesting undue pessimism about children's abilities to extract information based on the input. The modern 'nurture' approach is often referred to as the usage-based account. We discuss the usage-based account first, and then the nativist account. After that, we report and discuss the findings of several

  11. Root cortical senescence decreases root respiration, nutrient content, and radial water and nutrient transport in barley.

    Schneider, Hannah M; Wojciechowski, Tobias; Postma, Johannes A; Brown, Kathleen M; Lücke, Andreas; Zeisler, Viktoria; Schreiber, Lukas; Lynch, Jonathan P

    2017-02-06

    The functional implications of root cortical senescence (RCS) are poorly understood. We tested the hypotheses that RCS in barley: (1) reduces the respiration and nutrient content of root tissue; (2) decreases radial water and nutrient transport; (3) is accompanied by increased suberization to protect the stele. Genetic variation for RCS exists between modern germplasm and landraces. Nitrogen and phosphorus deficiency increased the rate of RCS. Maximal RCS, defined as the disappearance of the entire root cortex, reduced root nitrogen content by 66%, phosphorus content by 63%, and respiration by 87% compared to root segments with no RCS. Roots with maximal RCS had 90%, 92%, and 84% less radial water, nitrate, and phosphorus transport, respectively compared to segments with no RCS. The onset of RCS coincided with 30% greater aliphatic suberin in the endodermis. These results support the hypothesis that RCS reduces root carbon and nutrient costs and may therefore have adaptive significance for soil resource acquisition. By reducing root respiration and nutrient content, RCS could permit greater root growth, soil resource acquisition, and resource allocation to other plant processes. RCS merits investigation as a trait for improving the performance of barley, wheat, triticale, and rye under edaphic stress.

  12. Acquisition Support Program Overview

    2016-06-30

    Principles of Effective Acquisition © 2006 by Carnegie Mellon University page 31 Summary The SEI, through the Acquisition Support Program , works directly...2006 by Carnegie Mellon University page 1 Acquisition Support Program Overview Brian Gallagher Director, Acquisition Support Program 9 March, 2006...MAR 2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Acquisition Support Program Overview 5a. CONTRACT

  13. Nutrient sensing in the gastrointestinal tract: possible role for nutrient transporters.

    Raybould, H E

    2008-12-01

    Although it is well established that the presence of nutrients in the gut lumen can bring about changes in GI function, the mechanisms and pathways by which these changes occur has not been fully elucidated. It has been known for many years that luminal nutrients stimulate the release of hormones and regulatory peptides from gut endocrine cells and that luminal nutrients activate intrinsic and extrinsic neural pathways innervating the gut. Activation of gut endocrine cells and neural pathways by nutrients in the gut lumen is key in coordination of postprandial GI function and also in the regulation of food intake. Recent evidence suggests that these pathways can be modified by long term changes in diet or by inflammatory processes in the gut wall. Thus it is important to determine the cellular and molecular mechanisms underlying these processes not only to increase our understanding of as part of basic physiology but also to understand changes in these pathways that occur in the presence of pathophysiology and disease. This review summarizes some of the latest data that we have obtained, together with information from the other laboratories, which have elucidated some of the mechanisms involved in nutrient detection in the gut wall. The focus is on monosaccharides and protein hydrolysates as there is some evidence for a role for nutrient transporters in detection of these nutrients.

  14. Nutrient Control Seminars

    These Nutrient Control Seminars will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). These seminars will present ...

  15. 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…

  16. Study on the Government Guarantee Mechanism in the Information Acquisition Service for the Disabled%残疾人信息获取服务中的政府保障机制研究

    薛小婕

    2015-01-01

    Because of the limitation of physiological and psychological conditions, the disabled has been in a weak position in society, all kinds of barriers in access to information make it worse. The government has the responsibility and obligation to ensure access to information for the disabled. This paper introduces the existing government guarantee mechanism in the Information Acquisition Service for the disabled, and based on analyzing some problems existing in the information acquisition service for the disabled, puts forward the socialized mechanism guaranteed by the government, and expounds it on the detail.%残疾人由于生理、心理条件的限制,在社会中一直处于弱势地位,在获取信息时的种种障碍又使其雪上加霜,政府有责任和义务保障残疾人的信息获取. 介绍了现有残疾人信息获取服务中的政府保障机制,在分析其存在问题的基础上,提出了政府保障的社会化机制,并对其进行了详细的阐述.

  17. Nutrient synchrony in preruminant calves

    Borne, van den J.J.G.C.

    2006-01-01

    In animal nutrition, the nutrient composition of the daily feed supply is composed to match the nutrient requirements for the desired performance. The time of nutrient availability within a day is usually considered not to affect the fate of nutrients. The aim of this thesis was to evaluate effects

  18. 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...

  19. Maternal Nutrient Restriction Predisposes Ventricular Remodeling in Adult Sheep Offspring

    Ge, Wei; Hu, Nan; George, Lindsey A; Ford, Stephen P.; Peter W Nathanielsz; Wang, Xiaoming; Ren, Jun

    2013-01-01

    Maternal nutrient restriction during pregnancy is associated with the development of a “thrifty phenotype” in offspring, conferring increased prevalence of metabolic diseases in adulthood. To explore the possible mechanisms behind heart diseases in adulthood following maternal nutrient restriction, dams were fed a nutrient restricted (NR: 50%) or control (100%) diet from 28 to 78 d of gestation. Both groups were then fed 100% of requirements to lambing. At 6 yrs of age, female offspring of NR...

  20. 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.

  1. Software Acquisition Program Dynamics

    2011-10-24

    techniques to avoid these problems The Objective • Improve acquisition program staff decision-making, and thus improve acquisition program outcomes...classroom training, eLearning , certification, and more—to serve the needs of customers and partners worldwide.

  2. 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...

  3. Acquisition and Monitor of Mechanical Vibrations Signal Based on MSP430%基于MSP430的机械振动信号采集与监控系统

    张黠; 熊晓燕

    2012-01-01

    The high frequency signal of mechanical vibration designed a supervisory control and data acquisition system based on low power consumed MSP430FG4618 chip. The part of data acquisition was made up of the main control MSP430FG4618 chip, the radio chip of CC2420, and the tri-axial accelerometer of ADXL345. The part of control system used technology of WEB CGI, and it used the powerful data throughput of Ethernet to design a radio control system of CGI. The experiment shows the design of the system improves very well for the data acquisition and wireless data transmission reliability and stability, and it meets the requirements of the vibratory detection and monitoring for machinery and equipment.%基于低功耗单片机MSP430FG4618对高频机械振动信号设计出了数据采集与监控的一体化系统.对于振动信号的数据采集部分采用了主控芯片MSP430FG4618、无线发射芯片CC2420以及三轴加速度计ADXL345.在监控上采用WEB CGI(通用网关接口)技术,利用以太网强大的数据吞吐能力设计了监控系统.通过测试表明,系统对于信号采集和无线传输具有很高的可靠性和稳定性,能够满足机械设备的振动检测和监控要求.

  4. 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.

  5. 不同营养下混合菌种微生物污垢生长机理与交互作用%Growth and interaction mechanism of multi-strain biofouling under different nutrient levels

    杨倩鹏; 陈晓东; 田磊; 史琳

    2013-01-01

    再生水源热泵能有效回用废热,但再生水换热器的微生物污垢问题一直没有完全解决,严重影响换热效率和系统安全.利用长期监测并且进行16S rRNA鉴定得到的再生水及其污垢中两种主要代表菌属芽孢杆菌属和气单胞菌属,在实验室内配制模拟流体进行混合菌种微生物污垢实验.通过在特制的机理流道上进行不同菌种比例和不同营养物质浓度的污垢生长实验,得出芽孢杆菌属和气单胞菌属的单独生长规律和混合生长规律,总结了混合生长时两种菌属的协同和抑制规律,同时考察了营养物质浓度对生长规律和交互作用的影响.结果表明:芽孢杆菌属成垢能力较强,细胞分裂速度高,耐贫营养能力强;气单胞菌属成垢能力弱于芽孢杆菌属,但分泌物生成速率高,可以与芽孢杆菌属协同生长;两种菌属交互作用在不同阶段和条件下,协同与抑制作用共存并轮流占据主导.%Heat pump system is an effective method for heat recovery of a treated sewage source, but biofouling on heat exchanger is still a problem to be solved, and may affect seriously efficiency and security of the system. By long term monitoring and 16S rRNA identification, two major bacteria genus, Bacillus sp. and Aeromonas sp. , were selected for multi-strain biofouling experiment of a model fluid in laboratory. By the experiment of foul growth performed on a purpose made channel at various bacteria ratios and nutrient levels, the regular patterns of single and mixed microbe growth of Bacillus sp. and Aeromonas sp. were revealed, their synergy and inhibition interaction summarized, and the effect of nutrient levels on their growth mechanism and interaction also investigated. The results indicated that the Bacillus sp. has strong ability in biofouling, in high multiple rates, and high tolerance to poor nutrient level. The biofouling of Aeromonas sp. is weak relatively, but high secretion rate that may

  6. Dietary Restriction and Nutrient Balance in Aging

    Júlia Santos

    2016-01-01

    Full Text Available Dietary regimens that favour reduced calorie intake delay aging and age-associated diseases. New evidences revealed that nutritional balance of dietary components without food restriction increases lifespan. Particular nutrients as several nitrogen sources, proteins, amino acid, and ammonium are implicated in life and healthspan regulation in different model organisms from yeast to mammals. Aging and dietary restriction interact through partially overlapping mechanisms in the activation of the conserved nutrient-signalling pathways, mainly the insulin/insulin-like growth factor (IIS and the Target Of Rapamycin (TOR. The specific nutrients of dietary regimens, their balance, and how they interact with different genes and pathways are currently being uncovered. Taking into account that dietary regimes can largely influence overall human health and changes in risk factors such as cholesterol level and blood pressure, these new findings are of great importance to fully comprehend the interplay between diet and humans health.

  7. 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

  8. 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.

  9. Excessive acquisition in hoarding.

    Frost, Randy O; Tolin, David F; Steketee, Gail; Fitch, Kristin E; Selbo-Bruns, Alexandra

    2009-06-01

    Compulsive hoarding (the acquisition of and failure to discard large numbers of possessions) is associated with substantial health risk, impairment, and economic burden. However, little research has examined separate components of this definition, particularly excessive acquisition. The present study examined acquisition in hoarding. Participants, 878 self-identified with hoarding and 665 family informants (not matched to hoarding participants), completed an Internet survey. Among hoarding participants who met criteria for clinically significant hoarding, 61% met criteria for a diagnosis of compulsive buying and approximately 85% reported excessive acquisition. Family informants indicated that nearly 95% exhibited excessive acquisition. Those who acquired excessively had more severe hoarding; their hoarding had an earlier onset and resulted in more psychiatric work impairment days; and they experienced more symptoms of obsessive-compulsive disorder, depression, and anxiety. Two forms of excessive acquisition (buying and free things) each contributed independent variance in the prediction of hoarding severity and related symptoms.

  10. Sistema de aquisição automatica de dados para o gerenciamento de operações mecanizadas Automatic data acquisition system for mechanization management

    Gastão Moraes da Silveira

    2005-01-01

    Full Text Available Para difundir e popularizar técnicas de gestão de informações na agricultura são necessários esforços para prover o usuário de ferramentas de análise e de avaliação operacional. A versatilidade do trator agrícola o torna uma enorme fonte de informações que, se bem obtidas, analisadas e interpretadas, podem subsidiar o gerenciamento operacional da propriedade agrícola. Este trabalho apresenta o desenvolvimento de um sistema de aquisição automática de dados projetados para o levantamento de informações de campo. O sistema foi concebido para determinar a posição do veículo através de sistema de posicionamento global (GPS, juntamente com o consumo de combustível, a rotação do motor e a velocidade de deslocamento. Foram realizados experimentos visando verificar o funcionamento do sistema, por meio de da confrontação com outras técnicas de determinação do consumo de combustível, da rotação do motor e da velocidade de deslocamento. Concluiu-se que o consumo de combustível, não exige correção de dados, e a determinação da rotação do motor requer calibração.To spread out and to popularize the information management techniques in agriculture, efforts are necessary to provide the user with analysis and operational evaluation tools. The versatility of agricultural tractor becomes an enormous source of information; if it is well obtained, analyzed and interpreted, it can subsidize the farm management. This work presents the development of an automatic acquisition data system projected for field information. The system was conceived to determine the position of the vehicle using global positioning system (GPS, fuel consumption , engine rotation, and forward speed. This data set permits the statistical control the operational parameters and generates reports with the main management indicators as field capacity, and work conditions. Its spatial treatment makes possible the creation of a database that associated to

  11. Nutrients in the nexus

    Davidson, Eric A.; Niphong, Rachel; Ferguson, Richard B.; Palm, Cheryl; Osmond, Deanna L.; Baron, Jill S.

    2016-01-01

    Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twenty-first century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers’ fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socio-economic innovations in agriculture. Two case studies presented here, one in sub-Saharan Africa and the other in Midwestern United States, demonstrate how management of nutrients, water, and energy is inextricably linked in both small-scale and large-scale food production, and that science-based solutions to improve the efficiency of nutrient use can optimize food production while minimizing pollution. To achieve the needed large increases in nutrient use efficiency, however, technological developments must be accompanied by policies that recognize the complex economic and social factors affecting farmer decision-making and national policy priorities. Farmers need access to affordable nutrient supplies and support information, and the costs of improving efficiencies and avoiding pollution may need to be shared by society through innovative policies. Success will require interdisciplinary partnerships across public and private sectors, including farmers, private sector crop advisors, commodity supply chains, government agencies, university research and extension, and consumers.

  12. Acquisition IT Integration

    Henningsson, Stefan; Øhrgaard, Christian

    2015-01-01

    The IT integration of acquisitions consists an important challenge for the many acquiring organizations. Complementing existing research, this paper searches for explanation to differences in acquirers’ abilities for acquisition IT integration in the external of the acquirer, by a study of the use...... of temporary agency workers. Following an analytic induction approach, theoretically grounded in the re-source-based view of the firm, we identify the complimentary and supplementary roles consultants can assume in acquisition IT integration. Through case studies of three acquirers, we investigate how...... of the acquisition IT integration team should consider the balance of these, in practice, commonly mutually excluding needs....

  13. Fire alters ecosystem carbon and nutrients but not plant nutrient stoichiometry or composition in tropical savanna.

    Pellegrini, Adam F A; Hedin, Lars O; Staver, A Carla; Govender, Navashni

    2015-05-01

    Fire and nutrients interact to influence the global distribution and dynamics of the savanna biome, but the results of these interactions are both complex and poorly known. A critical but unresolved question is whether short-term losses of carbon and nutrients caused by fire can trigger long-term and potentially compensatory responses in the nutrient stoichiometry of plants, or in the abundance of dinitrogen-fixing trees. There is disagreement in the literature about the potential role of fire on savanna nutrients, and, in turn, on plant stoichiometry and composition. A major limitation has been the lack of fire manipulations over time scales sufficiently long for these interactions to emerge. We use a 58-year, replicated, large-scale, fire manipulation experiment in Kruger National Park (South Africa) in savanna to quantify the effect of fire on (1) distributions of carbon, nitrogen, and phosphorus at the ecosystem scale; (2) carbon: nitrogen: phosphorus stoichiometry of above- and belowground tissues of plant species; and (3) abundance of plant functional groups including nitrogen fixers. Our results show dramatic effects of fire on the relative distribution of nutrients in soils, but that individual plant stoichiometry and plant community composition remained unexpectedly resilient. Moreover, measures of nutrients and carbon stable isotopes allowed us to discount the role of tree cover change in favor of the turnover of herbaceous biomass as the primary mechanism that mediates a transition from low to high 'soil carbon and nutrients in the absence of fire. We conclude that, in contrast to extra-tropical grasslands or closed-canopy forests, vegetation in the savanna biome may be uniquely adapted to nutrient losses caused by recurring fire.

  14. Language Acquisitional Universals: L1, L2, Pidgins, and FLT.

    Wode, Henning

    Human capacity for language acquisition is not strictly compartmentalized, with one acquisitional mechanism for the native language and others totally unrelated to it; rather, it consists of a unified mechanism flexible enough to handle various differences in external settings. This learning system operates on the formal properties of the…

  15. Hierarchical security situational element acquisition mechanism in wireless sensor networks%无线传感器网络中层次化安全态势要素获取机制

    李方伟; 汪岩; 朱江; 张海波

    2016-01-01

    In wireless sensor network ,the processing ability of the sensor nodes is poor .And the security situational element acquisition is also a serious problem .Thus ,a hierarchical framework of security situational elements acquisition mechanism was proposed .In this framework ,support vector machine hyper sphere multi classification algorithm was introduced as basic classi‐fier .The non‐negative matrix factorization algorithm was used as the method of attribute reduction .The fuzzy classification algo‐rithm was used to initialize non‐negative matrix factorization ,to avoid the local optimal caused by random initialization of non‐negative matrix factorization .In the sink node ,classification rules and attribute reduction rules were formed by learning .The classification analyses respectively focused on the cluster head and sink node ,which reduced the requirement of the sensor node properties .Attribute reduction was carried out before the data transmission ,reducing communication consumption of data trans‐mission and improving the performance of classifiers .Simulation results show ,the scheme has preferable accuracy on the situa‐tional elements acquisition ,and smaller communication overhead in the process of information transmission .%针对无线传感器网络中感知节点处理能力较差,获取网络安全态势要素困难的问题,提出一种层次化架构态势要素获取机制。在该架构中,采用支持向量机超球体多分类算法作为基分类器,非负矩阵分解算法作为属性约简的方法,采用模糊分类算法初始化该算法,解决随机初始化导致局部最优的缺陷。在汇聚节点完成对分类规则和属性约简规则的学习,分别在簇头和汇聚节点做分类分析,降低对感知节点性能要求。数据传输前进行属性约简,减小数据传输时的通信开销,提高分类器分类性能。仿真结果表明,该方案有较好的态势要素获取准确度和

  16. 灾害事件和灾害过程驱动下Charter数据获取机制研究%Data acquisition mechanism of international Charter based on disaster events and processes

    和海霞; 陈伟涛; 吴玮; 李亚飞

    2014-01-01

    通过回顾“空间与重大灾害冶国际宪章( Charter)的发展历程、启动方式、运行机制及数据政策等情况,深入分析了Charter启动情况和中国应用案例。在此基础上,总结了目前Charter机制存在的主要问题,包括多灾并发及重灾频发时,Charter机制中存在启动条件缺乏、专题数据服务范围有限、统一调度系统尚未建立以及智能空间数据库管理系统需要优化等问题,因此造成了遥感数据的获取时效低、类型单一和自动化程度不高等问题。据此,提出了一种灾害事件和灾害过程驱动下的针对特定目标、解除时间窗口约束的动态自动化数据获取优化方案。结果表明:该方案能统筹用户需求、加强卫星调度,保障了多源数据获取的时效性和准确性,避免了数据冗余。%The development,activation,operating mechanism and data policy of international Charter were described in this paper. The activation and application cases aimed at investigating the disaster in China were analyzed. Then the main problems existent in Charter were summarized in the situation of concurrent multi-disaster and frequent severe disaster, which include the lack of activation condition and uniform operation system, the insufficient thematic data service, and the imperfect intellectual space databases system. These problems have led to the low efficiency in data acquisition, simple data type, and lower degree of automation. In order to solve these problems, this paper presented a dynamic and automatic data acquisition program aimed at the specific target, which can release time window constrains during the different disaster events and disaster processes. The results indicated that this program can pay more attention to the satellite scheduling and users' needs so as to ensure the timeliness and accuracy of multi-source data acquisition and avoid the data redundancy.

  17. Second language acquisition

    Kootstra, G.J.; Dijkstra, A.F.J.; Starren, M.B.P.

    2015-01-01

    This contribution provides an overview of second language acquisition research from a psycholinguistic perspective. The overview is mainly focused on cross-language interactions during word and sentence production and comprehension at different points in the second-language acquisition process. The

  18. Coring Sample Acquisition Tool

    Haddad, Nicolas E.; Murray, Saben D.; Walkemeyer, Phillip E.; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Kriechbaum, Kristopher L.; Richardson, Megan; Klein, Kerry J.

    2012-01-01

    A sample acquisition tool (SAT) has been developed that can be used autonomously to sample drill and capture rock cores. The tool is designed to accommodate core transfer using a sample tube to the IMSAH (integrated Mars sample acquisition and handling) SHEC (sample handling, encapsulation, and containerization) without ever touching the pristine core sample in the transfer process.

  19. Acquisition Research Program Homepage

    2015-01-01

    Includes an image of the main page on this date and compressed file containing additional web pages. Established in 2003, Naval Postgraduate School’s (NPS) Acquisition Research Program provides leadership in innovation, creative problem solving and an ongoing dialogue, contributing to the evolution of Department of Defense acquisition strategies.

  20. Mergers and Acquisitions

    Risberg, Annette

    Introduction to the study of mergers and acquisitions. This book provides an understanding of the mergers and acquisitions process, how and why they occur, and also the broader implications for organizations. It presents issues including motives and planning, partner selection, integration......, 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...... by editorial commentaries and reflects the important organizational and behavioural aspects which have often been ignored in the past. By providing this in-depth understanding of the mergers and acquisitions process, the reader understands not only how and why mergers and acquisitions occur, but also...

  1. Late gestational nutrient restriction

    Tygesen, Malin Plumhoff; Nielsen, Mette Olaf; Nørgaard, Peder;

    2008-01-01

    We investigated the effect of 50% nutrient restriction during the last 6 weeks of gestation on twin-pregnant ewes' plasma glucose, non-esterified fatty acid, ß-hydroxybutyrate, insulin, IGF-1 and leptin concentrations and the effects on lamb birth weight and ewes' lactation performance. Plasma...... metabolite and hormone concentrations in restricted ewes suggest that maternal tissues were being mobilised. Despite the ewes' adaptations their lambs weighed significantly less at birth. Furthermore, colostrum and milk yields were markedly reduced up until the latest measurement at 3 weeks post partum...

  2. 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.

  3. STIS target acquisition

    Kraemer, Steve; Downes, Ron; Katsanis, Rocio; Crenshaw, Mike; McGrath, Melissa; Robinson, Rich

    1997-01-01

    We describe the STIS autonomous target acquisition capabilities. We also present the results of dedicated tests executed as part of Cycle 7 calibration, following post-launch improvements to the Space Telescope Imaging Spectrograph (STIS) flight software. The residual pointing error from the acquisitions are < 0.5 CCD pixels, which is better than preflight estimates. Execution of peakups show clear improvement of target centering for slits of width 0.1 sec or smaller. These results may be used by Guest Observers in planning target acquisitions for their STIS programs.

  4. 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...

  5. Software Switching for Data Acquisition

    CERN. Geneva; Malone, David

    2016-01-01

    In this talk we discuss the feasibility of replacing telecom-class routers with a topology of commodity servers acting as software switches in data acquisition. We extend the popular software switch, Open vSwitch, with a dedicated, throughput-oriented buffering mechanism. We compare the performance under heavy many-to-one congestion to typical Ethernet switches and evaluate the scalability when building larger topologies, exploiting the integration with software-defined networking technologies. Please note that David Malone will speak on behalf of Grzegorz Jereczek.

  6. 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 America,...

  7. 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...

  8. Acquisition IT Integration

    Henningsson, Stefan; Øhrgaard, Christian

    2015-01-01

    The IT integration of acquisitions consists an important challenge for the many acquiring organizations. Complementing existing research, this paper searches for explanation to differences in acquirers’ abilities for acquisition IT integration in the external of the acquirer, by a study of the use...... of temporary agency workers. Following an analytic induction approach, theoretically grounded in the re-source-based view of the firm, we identify the complimentary and supplementary roles consultants can assume in acquisition IT integration. Through case studies of three acquirers, we investigate how...... 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...

  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. Nutrients, neurodevelopment, and mood.

    Casper, Regina C

    2004-12-01

    Human neurodevelopment is the result of genetic and environmental interactions. This paper examines the role of prenatal nutrition relative to psychiatric disorders and explores the relationship among nutrients, mood changes, and mood disorders. Epidemiologic studies have found that adults who were born with a normal, yet low birth weight have an increased susceptibility to diseases such as coronary heart disease, diabetes, and stroke in adulthood. Prenatal caloric malnutrition, low birth weight, and prematurity also increase the risk for neurodevelopmental disorders, schizophrenia, affective disorders, and schizoid and antisocial personality disorders. Placebo-controlled studies in medicated patients suggest that add-on treatment with omega-3 fatty acids, particularly eicosapentaenoic acid, may ameliorate symptoms of major depressive disorder. Additional studies are necessary to confirm any benefits for bipolar disorders.

  11. Nutrients and neurodevelopment: lipids.

    González, Horacio F; Visentin, Silvana

    2016-10-01

    Nutrients, lipids in particular, make up the central nervous system structure and play major functional roles: they stimulate development, migration, and nerve cell differentiation. They are part of gray matter, white matter, nerve nuclei, and synaptogenesis. Breast milk contains lipids which are crucial for infant brain development. The lipid profile of breast milk was used as a guideline for the development of breast milk substitutes. However, to date, no substitute has matched it. Complementary feeding should include docosahexaenoic acid, arachidonic acid, other polyunsaturated fatty acids, saturated fatty acids, and complex lipids found in milk fat. The lipid composition of breast milk depends on maternal intake and nutritional status during pregnancy and breast-feeding. It has a great impact on development. Our goal is to review scientific literature regarding the role of lipids on infant brain development and the importance of breast milk lipid composition, maternal diet, and complementary feeding.

  12. 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

  13. 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.

  14. 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)

  15. Nutrient management in substrate systems

    Sonneveld, C.; Voogt, W.

    2009-01-01

    Speaking about nutrient solutions in soilless cultivation, different solutions can be discerned. Originally, in soilless culture only one nutrient solution was taken into account, being the solution in the containers in which the plants were grown. Such solutions were intensively moved by air bubbli

  16. Nutrient Removal in Wastewater Treatment

    Shah, Kanti L.

    1973-01-01

    Discusses the sources and effects of nutrients in wastewater, and the methods of their removal in wastewater treatment. In order to conserve water resources and eliminate the cost of nutrient removal, treated effluent should be used wherever possible for irrigation, since it contains all the ingredients for proper plant growth. (JR)

  17. The effects of leaf litter nutrient pulses on Alliaria petiolata performance

    Robert W. Heckman

    2015-08-01

    Full Text Available Nutrient pulses can facilitate species establishment and spread in new habitats, particularly when one species more effectively uses that nutrient pulse. Biological differences in nutrient acquisition between native and exotic species may facilitate invasions into a variety of habitats including deciduous forest understories. Alliaria petiolata (Bieb. Cavara & Grande is an important invader of deciduous forest understories throughout much of North America. These understory communities contain many species which perform the majority of their growth and reproduction before canopy closure in spring. Because A. petiolata is a wintergreen biennial that can be active during autumn and winter, it may utilize nutrients released from decaying leaf litter before its competitors. To investigate this we manipulated the timing of leaf litter addition (fall or spring and experimentally simulated the nutrient pulse from decaying leaves using artificial fertilizer. To determine whether A. petiolata affected the abundance of understory competitors, we also removed A. petiolata from one treatment. A. petiolata that received early nutrients exhibited greater growth. Treatments receiving fall leaf litter or artificial nutrients had greater A. petiolata adult biomass than plots receiving spring nutrient additions (leaf litter or artificial nutrients. However, fall leaf litter addition had no effect on the richness of competitor species. Thus, wintergreen phenology may contribute to the spread of A. petiolata through deciduous forest understories, but may not explain community-level impacts of A. petiolata in deciduous forests.

  18. Iron acquisition mechanisms of Flavobacterium psychrophilum

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

    2005-01-01

    strains and was lacking from negative strains. While a weak catechol reaction was detectable in CAS+ culture supernatants, the CAS reaction was, to some extent, heat sensitive, questioning whether the positive reaction was caused only by siderophores. The ability to grow in vitro under iron...

  19. Brain mechanisms in early language acquisition.

    Kuhl, Patricia K

    2010-09-09

    The last decade has produced an explosion in neuroscience research examining young children's early processing of language. Noninvasive, safe functional brain measurements have now been proven feasible for use with children starting at birth. The phonetic level of language is especially accessible to experimental studies that document the innate state and the effect of learning on the brain. The neural signatures of learning at the phonetic level can be documented at a remarkably early point in development. Continuity in linguistic development from infants' earliest brain responses to phonetic stimuli is reflected in their language and prereading abilities in the second, third, and fifth year of life, a finding with theoretical and clinical impact. There is evidence that early mastery of the phonetic units of language requires learning in a social context. Neuroscience on early language learning is beginning to reveal the multiple brain systems that underlie the human language faculty.

  20. Nutrient sensing and inflammation in metabolic diseases.

    Hotamisligil, Gökhan S; Erbay, Ebru

    2008-12-01

    The proper functioning of the pathways that are involved in the sensing and management of nutrients is central to metabolic homeostasis and is therefore among the most fundamental requirements for survival. Metabolic systems are integrated with pathogen-sensing and immune responses, and these pathways are evolutionarily conserved. This close functional and molecular integration of the immune and metabolic systems is emerging as a crucial homeostatic mechanism, the dysfunction of which underlies many chronic metabolic diseases, including type 2 diabetes and atherosclerosis. In this Review we provide an overview of several important networks that sense and manage nutrients and discuss how they integrate with immune and inflammatory pathways to influence the physiological and pathological metabolic states in the body.

  1. 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.

  2. Dis-integrating Perspectives of Language Acquisition.

    Jacobs, Bob

    1995-01-01

    Responds to L. Eubank and K. R. Gregg article (this issue), suggesting they have misinterpreted and misrepresented claims made by B. Jacobs and J. Schumann. Claims discussed include the micro- and macro-organization of neurobiology and language, the Explananda, Jacobs and Schumann's acquisition mechanism, and reductionism. The single acquisition…

  3. 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.

  4. VERITAS Data Acquisition

    Hays, E.

    VERITAS employs a multi-stage data acquisition chain that extends from the VME readout of custom 500 MHz 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.

  5. 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.

  6. 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.

  7. Nutrient biofortification of food crops.

    Hirschi, Kendal D

    2009-01-01

    Plant-based foods offer an array of nutrients that are essential for human nutrition and promote good health. However, the major staple crops of the world are often deficient in some of these nutrients. Traditional agricultural approaches can marginally enhance the nutritional value of some foods, but the advances in molecular biology are rapidly being exploited to engineer crops with enhanced key nutrients. Nutritional targets include elevated mineral content, improved fatty acid composition, increased amino acid levels, and heightened antioxidant levels. Unfortunately, in many cases the benefits of these "biofortified" crops to human nutrition have not been demonstrated.

  8. Nutrient limitation and physiology mediate the fine-scale (de)coupling of biogeochemical cycles.

    Appling, Alison P; Heffernan, James B

    2014-09-01

    Nutrients in the environment are coupled over broad timescales (days to seasons) when organisms add or withdraw multiple nutrients simultaneously and in ratios that are roughly constant. But at finer timescales (seconds to days), nutrients become decoupled if physiological traits such as nutrient storage limits, circadian rhythms, or enzyme kinetics cause one nutrient to be processed faster than another. To explore the interactions among these coupling and decoupling mechanisms, we introduce a model in which organisms process resources via uptake, excretion, growth, respiration, and mortality according to adjustable trait parameters. The model predicts that uptake can couple the input of one nutrient to the export of another in a ratio reflecting biological demand stoichiometry, but coupling occurs only when the input nutrient is limiting. Temporal nutrient coupling may, therefore, be a useful indicator of ecosystem limitation status. Fine-scale patterns of nutrient coupling are further modulated by, and potentially diagnostic of, physiological traits governing growth, uptake, and internal nutrient storage. Together, limitation status and physiological traits create a complex and informative relationship between nutrient inputs and exports. Understanding the mechanisms behind that relationship could enrich interpretations of fine-scale time-series data such as those now emerging from in situ solute sensors.

  9. Porphyroblast crystallization kinetics: the role of the nutrient production rate

    Schwarz, Jens-Oliver; Engi, Martin; Berger, Alfons

    2011-01-01

    , such as grain size distributions. In turn, data on porphyroblast textures for natural samples are used to infer which mechanism dominated during their formation. Whereas previous models assume that the rate-limiting step for a porphyroblast producing reaction is either transport or growth, the model advanced...... in this study considers the production of nutrients for porphyroblasts as a potentially rate-limiting factor. This production reflects the breakdown of (metastable) reactants, which at a specific pressure (P) and temperature (T) depends on the bulk composition of the sample. The production of nutrients...... that potentially contribute to the formation of porphyroblasts is computed based on thermodynamic models. The conceptual model assumes that these nutrients feed into some intergranular medium, and products form by nutrient consumption from that medium, with rates depending on reaction affinity. For any sequence...

  10. 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...

  11. 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...

  12. Second Language Acquisition.

    McLaughlin, Barry; Harrington, Michael

    1989-01-01

    A distinction is drawn between representational and processing models of second-language acquisition. The first approach is derived primarily from linguistics, the second from psychology. Both fields, it is argued, need to collaborate more fully, overcoming disciplinary narrowness in order to achieve more fruitful research. (GLR)

  13. Merger and acquisition medicine.

    Powell, G S

    1997-01-01

    This discussion of the ramifications of corporate mergers and acquisitions for employees recognizes that employee adaptation to the change can be a long and complex process. The author describes a role the occupational physician can take in helping to minimize the potential adverse health impact of major organizational change.

  14. Acquisition of Comparison Constructions

    Hohaus, Vera; Tiemann, Sonja; Beck, Sigrid

    2014-01-01

    This article presents a study on the time course of the acquisition of comparison constructions. The order in which comparison constructions (comparatives, measure phrases, superlatives, degree questions, etc.) show up in English- and German-learning children's spontaneous speech is quite fixed. It is shown to be insufficiently determined by…

  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 investme

  16. Interaction and Language Acquisition

    孙红叶

    2016-01-01

    Based on Long's Interaction Hypothesis (IH), the paper examines the aspects of interaction that might facilitate natu-ralistic language development and goes further to propose features of interaction that could encourage classroom second lan-guage acquisition, in the hope that improved classroom interation will enhance teaching effectiveness in language classroom.

  17. 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

  18. Theories of early language acquisition.

    Plunkett, K

    1997-07-01

    What features of brain processing and neural development support linguistic development in young children? To what extent is the profile and timing of linguistic development in young children determined by a pre-ordained genetic programme? Does the environment play a crucial role in determining the patterns of change observed in children growing up? Recent experimental, neuroimaging and computational studies of developmental change in children promise to contribute to a deeper understanding of how the brain becomes wired up for language. In this review, the muttidisciplinary perspectives of cognitive neuroscience, experimental psycholinguistics and neural network modelling are brought to bear on four distinct areas in the study of language acquisition: early speech perception, word recognition, word learning and the acquisition of grammatical inflections. It is suggested that each area demonstrates how linguistic development can be driven by the interaction of general learning mechanisms, highly sensitive to particular statistical regularities in the input, with a richly structured environment which provides the necessary ingredients for the emergence of linguistic representations that support mature language processing. Similar epigenetic principles, guiding the emergence of linguistic structure, apply to all these domains, offering insights into phenomena ranging from the precocity of young infant's sensitivity to speech contrasts to the complexities of the problem facing the young child learning the arabic plural.

  19. Maximizing root/rhizosphere efficiency to improve crop productivity and nutrient use efficiency in intensive agriculture of China.

    Shen, Jianbo; Li, Chunjian; Mi, Guohua; Li, Long; Yuan, Lixing; Jiang, Rongfeng; Zhang, Fusuo

    2013-03-01

    Root and rhizosphere research has been conducted for many decades, but the underlying strategy of root/rhizosphere processes and management in intensive cropping systems remain largely to be determined. Improved grain production to meet the food demand of an increasing population has been highly dependent on chemical fertilizer input based on the traditionally assumed notion of 'high input, high output', which results in overuse of fertilizers but ignores the biological potential of roots or rhizosphere for efficient mobilization and acquisition of soil nutrients. Root exploration in soil nutrient resources and root-induced rhizosphere processes plays an important role in controlling nutrient transformation, efficient nutrient acquisition and use, and thus crop productivity. The efficiency of root/rhizosphere in terms of improved nutrient mobilization, acquisition, and use can be fully exploited by: (1) manipulating root growth (i.e. root development and size, root system architecture, and distribution); (2) regulating rhizosphere processes (i.e. rhizosphere acidification, organic anion and acid phosphatase exudation, localized application of nutrients, rhizosphere interactions, and use of efficient crop genotypes); and (3) optimizing root zone management to synchronize root growth and soil nutrient supply with demand of nutrients in cropping systems. Experiments have shown that root/rhizosphere management is an effective approach to increase both nutrient use efficiency and crop productivity for sustainable crop production. The objectives of this paper are to summarize the principles of root/rhizosphere management and provide an overview of some successful case studies on how to exploit the biological potential of root system and rhizosphere processes to improve crop productivity and nutrient use efficiency.

  20. Therapeutic perspectives of epigenetically active nutrients

    Remely, M; Lovrecic, L; de la Garza, A L; Migliore, L; Peterlin, B; Milagro, F I; Martinez, A J; Haslberger, A G

    2015-01-01

    Many nutrients are known for a wide range of activities in prevention and alleviation of various diseases. Recently, their potential role in regulating human health through effects on epigenetics has become evident, although specific mechanisms are still unclear. Thus, nutriepigenetics/nutriepigenomics has emerged as a new and promising field in current epigenetics research in the past few years. In particular, polyphenols, as part of the central dynamic interaction between the genome and the environment with specificity at physiological concentrations, are well known to affect mechanisms underlying human health. This review summarizes the effects of dietary compounds on epigenetic mechanisms in the regulation of gene expression including expression of enzymes and other molecules responsible for drug absorption, distribution, metabolism and excretion in cancer, metabolic syndrome, neurodegenerative disorders and hormonal dysfunction. PMID:25046997

  1. Nutrient Administration and Resistance Training

    Leutholtz Brian

    2005-06-01

    Full Text Available Abstract Skeletal muscle tissue is tightly regulated throughout our bodies by balancing its synthesis and breakdown. Many factors are known to exist that cause profound changes on the overall status of skeletal muscle, some of which include exercise, nutrition, hormonal influences and disease. Muscle hypertrophy results when protein synthesis is greater than protein breakdown. Resistance training is a popular form of exercise that has been shown to increase muscular strength and muscular hypertrophy. In general, resistance training causes a stimulation of protein synthesis as well as an increase in protein breakdown, resulting in a negative balance of protein. Providing nutrients, specifically amino acids, helps to stimulate protein synthesis and improve the overall net balance of protein. Strategies to increase the concentration and availability of amino acids after resistance exercise are of great interest and have been shown to effectively increase overall protein synthesis. 123 After exercise, providing carbohydrate has been shown to mildly stimulate protein synthesis while addition of free amino acids prior to and after exercise, specifically essential amino acids, causes a rapid pronounced increase in protein synthesis as well as protein balance.13 Evidence exists for a dose-response relationship of infused amino acids while no specific regimen exists for optimal dosing upon ingestion. Ingestion of whole or intact protein sources (e.g., protein powders, meal-replacements has been shown to cause similar improvements in protein balance after resistance exercise when compared to free amino acid supplements. Future research should seek to determine optimal dosing of ingested intact amino acids in addition to identifying the cellular mechanistic machinery (e.g. transcriptional and translational mechanisms for causing the increase in protein synthesis.

  2. Matéria seca e acúmulo de nutrientes em genótipos de milho contrastantes quanto a aquisição de fósforo Dry matter and mineral nutrition in efficient corn genotypes in relation to phosphurus acquisition

    Edílson Carvalho Brasil

    2007-06-01

    Full Text Available Com o intuito de avaliar o efeito do estresse de P sobre atributos morfológicos do sistema radicular de genótipos de milho contrastantes quanto a eficiência na aquisição de fósforo, conduziu-se um experimento em casa-de-vegetação da Embrapa Milho e Sorgo, Sete Lagoas, MG, onde foram testados oito genótipos de milho, provenientes do programa de melhoramento da Empresa. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 8 x 2, com três repetições, correspondendo a oito genótipos (três linhagens: L1 = ineficiente, L2 e L3 = eficientes; e cinco híbridos: H1, H2 e H3 = eficientes, H4 e H5 = ineficientes e dois níveis de P (baixo e alto. As plantas foram crescidas em solução nutritiva com duas concentrações de P equivalentes a 2,3 µM e 129 µM. A composição da solução nutritiva foi a seguinte, em mg L-1: N-NO3 152; N-NH4 18,2; Ca 141,1; K 90,1; Mg 20,8; S 18,8; Fe 4,3; Mn 0,5; B 0,27; Cu 0,04; Zn 0,15; Mo 0,08; Na 0,04 e HEDTA 20,06. Aos 18 dias do transplantio, verificou-se que, sob condições de estresse de P em solução nutritiva, os híbridos H5, H1 e H2 apresentaram os maiores valores de massa seca total e da parte aérea, em relação aos demais. De modo geral, tanto os híbridos como as linhagens, quando foram crescidos em solução com baixo nível de P, apresentaram maior relação raiz/parte aérea, do que os materiais que cresceram em solução com alto nível do nutriente. A concentração de N na parte aérea das plantas foi significativamente superior no tratamento com baixo nível de P na solução nutritiva. Os híbridos H1 e H2 e a linhagens L3 acumularam as maiores quantidades de P na parte aérea, independentemente do nível de P na solução. Esses resultados foram influenciados pelas maiores produções de produção de matéria seca apresentadas pelos referidos materiais. Independente do nível de P houve variação no conteúdo do nutriente na parte aérea dos h

  3. 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.

  4. The Genome-Wide Interaction Network of Nutrient Stress Genes in Escherichia coli

    Jean-Philippe Côtôé

    2016-11-01

    Full Text Available Conventional efforts to describe essential genes in bacteria have typically emphasized nutrient-rich growth conditions. Of note, however, are the set of genes that become essential when bacteria are grown under nutrient stress. For example, more than 100 genes become indispensable when the model bacterium Escherichia coli is grown on nutrient-limited media, and many of these nutrient stress genes have also been shown to be important for the growth of various bacterial pathogens in vivo. To better understand the genetic network that underpins nutrient stress in E. coli, we performed a genome-scale cross of strains harboring deletions in some 82 nutrient stress genes with the entire E. coli gene deletion collection (Keio to create 315,400 double deletion mutants. An analysis of the growth of the resulting strains on rich microbiological media revealed an average of 23 synthetic sick or lethal genetic interactions for each nutrient stress gene, suggesting that the network defining nutrient stress is surprisingly complex. A vast majority of these interactions involved genes of unknown function or genes of unrelated pathways. The most profound synthetic lethal interactions were between nutrient acquisition and biosynthesis. Further, the interaction map reveals remarkable metabolic robustness in E. coli through pathway redundancies. In all, the genetic interaction network provides a powerful tool to mine and identify missing links in nutrient synthesis and to further characterize genes of unknown function in E. coli. Moreover, understanding of bacterial growth under nutrient stress could aid in the development of novel antibiotic discovery platforms.

  5. Language acquisition is model-based rather than model-free.

    Wang, Felix Hao; Mintz, Toben H

    2016-01-01

    Christiansen & Chater (C&C) propose that learning language is learning to process language. However, we believe that the general-purpose prediction mechanism they propose is insufficient to account for many phenomena in language acquisition. We argue from theoretical considerations and empirical evidence that many acquisition tasks are model-based, and that different acquisition tasks require different, specialized models.

  6. 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

  7. 干出和沉水不同条件下羊栖菜光合作用碳源获得机制比较%Comparative Mechanisms of Photosynthetic Carbon Acquisition in Hizikia fusiforme Under Submersed and Emersed Conditions

    邹定辉; 高坤山

    2004-01-01

    经济海洋褐藻羊栖菜(Hizikia fusiforme(Harv.)Okamura)低潮时常常周期性地暴露于空气中.为了认识这种海藻在潮汐循环背景下的光合特征,对其在高潮沉水和低潮干出不同条件下的光合作用碳素获得机制进行了比较.沉水时,羊栖菜主要利用海水中HCO3-作为外源无机碳源驱动光合作用;而在干出条件下,其光合作用的主要碳源为空气中的CO2.在这两种不同环境条件下,光合作用与pH值的关系不同:沉水状态时,羊栖菜在高pH值(10.0)下光合活性很弱;而在干出条件下,羊栖菜在高pH值时仍有较高的光合活性.然而,光合作用无论是在沉水还是在干出条件下,对外源碳源的获得都表现出对胞外碳酸酐酶(CA)强烈的依赖性,并且其光合速率都受周围环境中无机碳源水平的限制.此外,在沉水和干出两种环境条件下,羊栖菜光合作用都表现出对氧气的敏感性.这表明,在羊栖菜中,依赖胞外CA的碳源获得机制不能使细胞内CO2浓度提高到阻碍其光呼吸的程度.增加空气中或海水中无机碳的浓度,能促进羊栖菜的光合作用,进而增加这种海藻的水产养殖产量.%The economic seaweed Hizikia fusiforme (Harv.) Okamura (Sargassaceae, Phaeophyta) usually experiences periodical exposures to air at low tide. Photosynthetic carbon acquisition mechanisms were comparatively studied under submersed and emersed conditions in order to establish a general understanding of its photosynthetic characteristics associated with tidal cycles. When submersed in seawater,H. fusiforme was capable of acquiring HCO3- as a source of inorganic carbon (Ci) to drive photosynthesis,while emersed and exposed to air, it used atmospheric CO2 for photosynthesis. The pH changes surrounding the H. fusiforme fronds had less influence on the photosynthetic rates under emersed condition than under submersed condition. When the pH was as high as 10.0, emersed H. fusiforme could

  8. Locative Terms and Warlpiri Acquisition.

    Bavin, Edith L.

    1990-01-01

    Focuses on the influence of language specific properties in the acquisition of locative expressions. Some of the claims from literature on the acquisition of locative expressions are discussed and data from the acquisition of Warlpiri are presented and discussed in terms of these claims. (Author/CB)

  9. 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…

  10. 21 CFR 107.100 - Nutrient specifications.

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Nutrient specifications. 107.100 Section 107.100... FOR HUMAN CONSUMPTION INFANT FORMULA Nutrient Requirements § 107.100 Nutrient specifications. (a) An infant formula shall contain the following nutrients at a level not less than the minimum level...

  11. 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.

  12. 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.

  13. 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...

  14. Based on Private Benefits of Control Perspective to Study the Success of Mergers and Acquisitions Paradox Formation Mechanism%控制权私利下并购成功悖论形成机制研究

    于成永; 施建军

    2012-01-01

    The success paradox has been puzzling the enterprise M&A theory and practice for a long time. This article based on the perspective of the private benefits of control studied success paradox formation mechanism, and got three conclusions: First, no matter incentive based or selfinterest based consisting main ly of private benefits of control, it can be advantageous to people having the right of control, therefore, the company will actively implement M&A; Second is in the selfinterest of private benefits of control, M&A is not conducive to medi um and small shareholders interest, so the performance of merging enterprises is negative; Third is to stimulate mainly private benefits of control, M&A is not necessarily conducive to minority shareholders. Shareholders increase public bene fits is to improve the performance of mergers and acquisitions. The fact that the performance of merging enterprises is zero or negative implies that it is neces sary to redesign the system to enhance the total revenue sharing in line with the controlling interest.%并购成功悖论一直困绕着企业并购理论与实务界。本文从控制权私利视角研究了成功悖论形成机制,得到三点结论:一是无论激励为主还是自利为主的控制权私利均有利于控制权人,因而,控制人控制的企业会积极实施并购;二是在自利为主的控制权私利下,并购必然不利于中小股东利益,因而主并方并购绩效为负值;三是以激励为主的控制权私利下,并购并不必然有利于中小股东,提升大小股东共有收益,并保证中小股东得到应有收益份额才有利于改善并购绩效。主并方并购绩效多为零或负值说明制度上重新设计以保障提升共有收益更符合控制权人利益是必要的。

  15. Second language acquisition

    Indefrey, P.; Davidson, D.

    2014-01-01

    This article reviews neurocognitive evidence on second language (L2) processing at speech sound, word, and sentence levels. Hemodynamic (functional magnetic resonance imaging and positron emission tomography) data suggest that L2s are implemented in the same brain structures as the native language but with quantitative differences in the strength of activation that are modulated by age of L2 acquisition and L2 proficiency. Electrophysiological data show a more complex pattern of first and L2 ...

  16. Stock market driven acquisitions

    Shleifer, Andrei; Vishny, Robert W.

    2003-01-01

    We present a model of mergers and acquisitions based on stock market misvaluations of the combining firms. The key ingredients of the model are the relative valuations of the merging firms and the market’s perception of the synergies from the combination. The model explains who acquires whom, the choice of the medium of payment, the valuation consequences of mergers, and merger waves. The model is consistent with available empirical findings about characteristics and returns of merging firms,...

  17. Stock Market Driven Acquisitions

    Andrei Shleifer; Vishny, Robert W.

    2001-01-01

    We present a model of mergers and acquisitions based on stock market misvaluations of the combining firms. The key ingredients of the model are the relative valuations of the merging firms, the horizons of their respective managers, and the market's perception of the synergies from the combination. The model explains who acquirers whom, whether the medium of payment is cash or stock, what are the valuation consequences of mergers, and why there are merger waves. The model is consistent with a...

  18. Second language acquisition.

    Juffs, Alan

    2011-05-01

    Second language acquisition (SLA) is a field that investigates child and adult SLA from a variety of theoretical perspectives. This article provides a survey of some key areas of concern including formal generative theory and emergentist theory in the areas of morpho-syntax and phonology. The review details the theoretical stance of the two different approaches to the nature of language: generative linguistics and general cognitive approaches. Some results of key acquisition studies from the two theoretical frameworks are discussed. From a generative perspective, constraints on wh-movement, feature geometry and syllable structure, and morphological development are highlighted. From a general cognitive point of view, the emergence of tense and aspect marking from a prototype account of inherent lexical aspect is reviewed. Reference is made to general cognitive learning theories and to sociocultural theory. The article also reviews individual differences research, specifically debate on the critical period in adult language acquisition, motivation, and memory. Finally, the article discusses the relationship between SLA research and second language pedagogy. Suggestions for further reading from recent handbooks on SLA are provided. WIREs Cogni Sci 2011 2 277-286 DOI: 10.1002/wcs.106 For further resources related to this article, please visit the WIREs website.

  19. Complexity in language acquisition.

    Clark, Alexander; Lappin, Shalom

    2013-01-01

    Learning theory has frequently been applied to language acquisition, but discussion has largely focused on information theoretic problems-in particular on the absence of direct negative evidence. Such arguments typically neglect the probabilistic nature of cognition and learning in general. We argue first that these arguments, and analyses based on them, suffer from a major flaw: they systematically conflate the hypothesis class and the learnable concept class. As a result, they do not allow one to draw significant conclusions about the learner. Second, we claim that the real problem for language learning is the computational complexity of constructing a hypothesis from input data. Studying this problem allows for a more direct approach to the object of study--the language acquisition device-rather than the learnable class of languages, which is epiphenomenal and possibly hard to characterize. The learnability results informed by complexity studies are much more insightful. They strongly suggest that target grammars need to be objective, in the sense that the primitive elements of these grammars are based on objectively definable properties of the language itself. These considerations support the view that language acquisition proceeds primarily through data-driven learning of some form.

  20. TOR Signaling and Nutrient Sensing.

    Dobrenel, Thomas; Caldana, Camila; Hanson, Johannes; Robaglia, Christophe; Vincentz, Michel; Veit, Bruce; Meyer, Christian

    2016-04-29

    All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth.

  1. Nutrient canal of the fibula

    Lee, Joo-Hyuk; Ehara, Shigeru; Tamakawa, Yoshiharu [Departments of Radiology, Iwate Medical University School of Medicine, Morioka (Japan); Horiguchi, Masahura [Department of Anatomy I, Iwate Medical University School of Medicine, Morioka (Japan)

    2000-01-01

    Objective. To investigate the radiological features of the nutrient canal in the fibula.Design and patients. One hundred and seventy-nine dried fibulae were studied regarding the type, number, location, and direction of the nutrient canal. They were classified into a usual type (type I: a radiolucent line confined to the cortex) and an atypical type (type II: a radiolucent line extending beyond the cortex).Results. Among the total of 230 nutrient canals seen on radiography, 197 (86%) were type I and 33 (14%) were type II. On CT scans, the ossified rim of the canal extended into the medullary cavity in type II canals. The most common site was the posteromedial aspect in both type I and type II canals. Type II canals were significantly more common in fibulae with two or three nutrient canals. The frequency of the upward direction was more common in type II canals.Conclusion. Nutrient canals with extension of the ossified rim into the medullary canal are the cause of linear lucency that may simulate a fracture. Their features are slightly different from those of usual canals. (orig.)

  2. Nutrient density: principles and evaluation tools.

    Drewnowski, Adam; Fulgoni, Victor L

    2014-05-01

    Nutrient profiling is the technique of rating or classifying foods on the basis of their nutritional value. Foods that supply relatively more nutrients than calories are defined as nutrient dense. Nutrient profile models calculate the content of key nutrients per 100 g, 100 kcal, or per serving size of food. For maximum effectiveness, nutrient profile models need to be transparent, based on publicly accessible nutrient composition data, and validated against independent measures of a healthy diet. These rigorous scientific standards were applied to the development of the Nutrient-Rich Foods (NRF) family of nutrient profile models. First, the NRF models included nutrients to encourage as well as nutrients to limit. Second, NRF model performance was repeatedly tested against the Healthy Eating Index (HEI), an independent measure of a healthy diet. HEI values were calculated for participants in the 1999-2002 NHANES. Models based on 100 kcal and serving sizes performed better than those based on 100 g. Formulas based on sums and means performed better than those based on ratios. The final NRF9.3 index was based on 9 beneficial nutrients (protein; fiber; vitamins A, C, and E; calcium; iron; potassium; and magnesium) and on 3 nutrients to limit (saturated fat, added sugar, and sodium). Higher NRF9.3 scores were associated with lower energy density and more nutrient-rich diets. The nutrient density of foods, paired with a comprehensive program of consumer education, can become the foundation of dietary recommendations and guidelines.

  3. Reduction of transpiration and altered nutrient allocation contribute to nutrient decline of crops grown in elevated CO(2) concentrations.

    McGrath, Justin M; Lobell, David B

    2013-03-01

    Plants grown in elevated [CO(2) ] have lower protein and mineral concentrations compared with plants grown in ambient [CO(2) ]. Dilution by enhanced production of carbohydrates is a likely cause, but it cannot explain all of the reductions. Two proposed, but untested, hypotheses are that (1) reduced canopy transpiration reduces mass flow of nutrients to the roots thus reducing nutrient uptake and (2) changes in metabolite or enzyme concentrations caused by physiological changes alter requirements for minerals as protein cofactors or in other organic complexes, shifting allocation between tissues and possibly altering uptake. Here, we use the meta-analysis of previous studies in crops to test these hypotheses. Nutrients acquired mostly by mass flow were decreased significantly more by elevated [CO(2) ] than nutrients acquired by diffusion to the roots through the soil, supporting the first hypothesis. Similarly, Mg showed large concentration declines in leaves and wheat stems, but smaller decreases in other tissues. Because chlorophyll requires a large fraction of total plant Mg, and chlorophyll concentration is reduced by growth in elevated [CO(2) ], this supports the second hypothesis. Understanding these mechanisms may guide efforts to improve nutrient content, and allow modeling of nutrient changes and health impacts under future climate change scenarios.

  4. Connectionist Models: Implications in Second Language Acquisition

    Farid Ghaemi

    2011-10-01

    Full Text Available In language acquisition, ‘Emergentists’ claim that simple learning mechanisms, of the kind attested elsewhere in cognition, are sufficient to bring about the emergence of complex language
    representations (Gregg, 2003. Connectionist model is one of the models among others proposed by emergentists. This paper attempts to clarify the basic assumptions of this model, its advantages, and the criticisms leveled at it.

  5. Terrestrial plants require nutrients in similar proportions.

    Knecht, Magnus F; Göransson, Anders

    2004-04-01

    Theoretical considerations based on nutrition experiments suggest that nutrient ratios of terrestrial plants are similar to the Redfield ratio found in marine phytoplankton. Laboratory experiments have shown that seedlings of many different plant species have similar nutrient concentration ratios when supplied with nutrients at free access. However, at free access, nutrients are likely to be taken up in amounts in excess of a plant's requirements for growth. In further experiments, therefore, the supply rate of each nutrient was reduced so that excessive uptake did not occur. Again, similar nutrient ratios were found among the plant species tested, although the ratios differed from those found in plants given free access to nutrients. Based on the law of the minimum, we suggest that optimum nutrient ratios be defined as the ratios found in plants when all nutrients are limiting growth simultaneously. The literature on nutrient concentrations was surveyed to investigate nutrient ratios in terrestrial ecosystems. Nutrients taken into consideration were nitrogen, phosphorus, potassium, calcium and magnesium. Based on the assumption that nitrogen is either the limiting nutrient or, when not limiting, is taken up only in small excess amounts, we calculated nutrient ratios from published data. The calculated ratios corresponded closely to the ratios determined in laboratory and field experiments.

  6. Saharan dust nutrients promote Vibrio bloom formation in marine surface waters

    Westrich, Jason R.; Ebling, Alina M.; Landing, William M.; Joyner, Jessica L.; Kemp, Keri M.; Griffin, Dale W.; Lipp, Erin K.

    2016-01-01

    Vibrio is a ubiquitous genus of marine bacteria, typically comprising a small fraction of the total microbial community in surface waters, but capable of becoming a dominant taxon in response to poorly characterized factors. Iron (Fe), often restricted by limited bioavailability and low external supply, is an essential micronutrient that can limit Vibrio growth. Vibrio species have robust metabolic capabilities and an array of Fe-acquisition mechanisms, and are able to respond rapidly to nutrient influx, yet Vibrio response to environmental pulses of Fe remains uncharacterized. Here we examined the population growth of Vibrioafter natural and simulated pulses of atmospherically transported Saharan dust, an important and episodic source of Fe to tropical marine waters. As a model for opportunistic bacterial heterotrophs, we demonstrated that Vibrio proliferate in response to a broad range of dust-Fe additions at rapid timescales. Within 24 h of exposure, strains of Vibrio cholerae and Vibrio alginolyticus were able to directly use Saharan dust–Fe to support rapid growth. These findings were also confirmed with in situ field studies; arrival of Saharan dust in the Caribbean and subtropical Atlantic coincided with high levels of dissolved Fe, followed by up to a 30-fold increase of culturable Vibrio over background levels within 24 h. The relative abundance of Vibrio increased from ∼1 to ∼20% of the total microbial community. This study, to our knowledge, is the first to describe Vibrio response to Saharan dust nutrients, having implications at the intersection of marine ecology, Fe biogeochemistry, and both human and environmental health.

  7. The NUSTAR data acquisition

    Loeher, B.; Toernqvist, H.T. [TU Darmstadt (Germany); GSI (Germany); Agramunt, J. [IFIC, CSIC (Spain); Bendel, M.; Gernhaeuser, R.; Le Bleis, T.; Winkel, M. [TU Muenchen (Germany); Charpy, A.; Heinz, A.; Johansson, H.T. [Chalmers University of Technology (Sweden); Coleman-Smith, P.; Lazarus, I.H.; Pucknell, V.F.E. [STFC Daresbury (United Kingdom); Czermak, A. [IFJ (Poland); Kurz, N.; Nociforo, C.; Pietri, S.; Schaffner, H.; Simon, H. [GSI (Germany); Scheit, H. [TU Darmstadt (Germany); Taieb, J. [CEA (France)

    2015-07-01

    The diversity of upcoming experiments within the NUSTAR collaboration, including experiments in storage rings, reactions at relativistic energies and high-precision spectroscopy, is reflected in the diversity of the required detection systems. A challenging task is to incorporate the different needs of individual detectors within the unified NUSTAR Data AcQuisition (NDAQ). NDAQ takes up this challenge by providing a high degree of availability via continuously running systems, high flexibility via experiment-specific configuration files for data streams and trigger logic, distributed timestamps and trigger information on km distances, all built on the solid basis of the GSI Multi-Branch System. NDAQ ensures interoperability between individual NUSTAR detectors and allows merging of formerly separate data streams according to the needs of all experiments, increasing reliability in NUSTAR data acquisition. An overview of the NDAQ infrastructure and the current progress is presented. The NUSTAR (NUclear STructure, Astrophysics and Reactions) collaboration represents one of the four pillars motivating the construction of the international FAIR facility. The diversity of NUSTAR experiments, including experiments in storage rings, reactions at relativistic energies and high-precision spectroscopy, is reflected in the diversity of the required detection systems. A challenging task is to incorporate the different needs of individual detectors and components under the umbrella of the unified NUSTAR Data AQuisition (NDAQ) infrastructure. NDAQ takes up this challenge by providing a high degree of availability via continuously running systems, high flexibility via experiment-specific configuration files for data streams and trigger logic, and distributed time stamps and trigger information on km distances, all built on the solid basis of the GSI Multi-Branch System (MBS). NDAQ ensures interoperability between individual NUSTAR detectors and allows merging of formerly separate

  8. Variations of nutrient elements and its effect on ecological environment off the Changjiang estuarine waters

    2001-01-01

    On the basis of the data obtained in two cruises during October 1997 and May 1998, the concentration distribution and the variation of present species of nutrient elements in the water masses are described. The transform mechanism of present species of nutrients and role of differmt water masses, frontal area and thermohaline transition layer on convergence or divergence and the biogeochemical cycle of nutrient elements off the Changjiang Estuary are studied. Meanwhile, the environmental capacityof nutrients is primarily estimated: they are 1.803 × 104t DIN and 6.18 × 102t PO43- - P in autumn, and 4.20 × 102t PO43- -p in spring.

  9. Data needs for nutrient balances

    Vinther, Finn Pilgaard

    2011-01-01

    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, countrie...

  10. 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

  11. 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.

  12. Nutrient resorption from seagrass leaves

    Stapel, J.; Hemminga, M.A.

    1997-01-01

    The resorption of nutrients (C, N and P) from senescent leaves of six seagrass species from nine different locations in tropical (Indonesia and Kenya), Mediterranean (Spain) and temperate (The Netherlands) regions has been investigated. Resorption was quantitatively assessed by calculating the diffe

  13. 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...

  14. Impact of glyphosate resistant corn, glyphosate applications, and tillage on soil nutrient ratios, exoenzyme activities, and nutrient acquisition ratios

    We report results of the last two years of a 7-year (2008-2014) field experiment designed to test the null hypothesis that applications of glyphosate on glyphosate resistant corn (Zea mays L.) as a routine weed control practice under both conventional and reduced tillage practices would have no effe...

  15. A smart market for nutrient credit trading to incentivize wetland construction

    Raffensperger, John F.; Prabodanie, R. A. Ranga; Kostel, Jill A.

    2017-03-01

    Nutrient trading and constructed wetlands are widely discussed solutions to reduce nutrient pollution. Nutrient markets usually include agricultural nonpoint sources and municipal and industrial point sources, but these markets rarely include investors who construct wetlands to sell nutrient reduction credits. We propose a new market design for trading nutrient credits, with both point source and non-point source traders, explicitly incorporating the option of landowners to build nutrient removal wetlands. The proposed trading program is designed as a smart market with centralized clearing, done with an optimization. The market design addresses the varying impacts of runoff over space and time, and the lumpiness of wetland investments. We simulated the market for the Big Bureau Creek watershed in north-central Illinois. We found that the proposed smart market would incentivize wetland construction by assuring reasonable payments for the ecosystem services provided. The proposed market mechanism selects wetland locations strategically taking into account both the cost and nutrient removal efficiencies. The centralized market produces locational prices that would incentivize farmers to reduce nutrients, which is voluntary. As we illustrate, wetland builders' participation in nutrient trading would enable the point sources and environmental organizations to buy low cost nutrient credits.

  16. Plant Nitrogen Acquisition Under Low Availability: Regulation of Uptake and Root Architecture.

    Kiba, Takatoshi; Krapp, Anne

    2016-04-01

    Nitrogen availability is a major factor determining plant growth and productivity. Plants acquire nitrogen nutrients from the soil through their roots mostly in the form of ammonium and nitrate. Since these nutrients are scarce in natural soils, plants have evolved adaptive responses to cope with the environment. One of the most important responses is the regulation of nitrogen acquisition efficiency. This review provides an update on the molecular determinants of two major drivers of the nitrogen acquisition efficiency: (i) uptake activity (e.g. high-affinity nitrogen transporters) and (ii) root architecture (e.g. low-nitrogen-availability-specific regulators of primary and lateral root growth). Major emphasis is laid on the regulation of these determinants by nitrogen supply at the transcriptional and post-transcriptional levels, which enables plants to optimize nitrogen acquisition efficiency under low nitrogen availability.

  17. 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.

  18. Data-acquisition systems

    Cyborski, D.R.; Teh, K.M.

    1995-08-01

    Up to now, DAPHNE, the data-acquisition system developed for ATLAS, was used routinely for experiments at ATLAS and the Dynamitron. More recently, the Division implemented 2 MSU/DAPHNE systems. The MSU/DAPHNE system is a hybrid data-acquisition system which combines the front-end of the Michigan State University (MSU) DA system with the traditional DAPHNE back-end. The MSU front-end is based on commercially available modules. This alleviates the problems encountered with the DAPHNE front-end which is based on custom designed electronics. The first MSU system was obtained for the APEX experiment and was used there successfully. A second MSU front-end, purchased as a backup for the APEX experiment, was installed as a fully-independent second MSU/DAPHNE system with the procurement of a DEC 3000 Alpha host computer, and was used successfully for data-taking in an experiment at ATLAS. Additional hardware for a third system was bought and will be installed. With the availability of 2 MSU/DAPHNE systems in addition to the existing APEX setup, it is planned that the existing DAPHNE front-end will be decommissioned.

  19. Unsupervised Language Acquisition

    de Marcken, Carl

    1996-11-01

    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 unsegmented text and continuous speech, and mappings between sound and representations of meaning. It performs extremely well on various objective criteria, acquiring knowledge that causes it to assign almost exactly the same structure to utterances as humans do. This work has application to data compression, language modeling, speech recognition, machine translation, information retrieval, and other tasks that rely on either structural or stochastic descriptions of language.

  20. [Response of fine roots to soil nutrient spatial heterogeneity].

    Wang, Qingcheng; Cheng, Yunhuan

    2004-06-01

    The spatial heterogeneity is the complexity and variation of systems or their attributes, and the heterogeneity of soil nutrients is ubiquitous in all natural ecosystems. The scale of spatial heterogeneity varies considerably among different ecosystems, from tens of centimeters to hundred meters. Some of the scales can be detected by individual plant. Because the growth of individual plants can be strongly influenced by soil heterogeneity, it follows that the inter-specific competition should also be affected. During the long process of evolution, plants developed various plastic responses with their root system, including morphological, physiological and mycorrhizal plasticity, to maximize the nutrient acquisition from heterogeneous soil resources. Morphological plasticity, an adjustment in root system spatial allocation and architecture in response to spatial heterogeneous distribution of available soil resources, has been most intensively studied, and root proliferation in nutrient rich patches has been certified for many species. The species that do respond may have an increased rate of nutrient uptake, leading to a competitive advantage. Scale and precision are two important features employed in describing the size and foraging behavior of root system. It was hypothesized that scale and precision is negatively related, i. e., the species with high scale of root system tend to be a less precise forager. The outcomes of different research work have been diverse, far from reaching a consensus. Species with high scale are not necessarily less precise in fine root allocation, and vice versa. The proliferation of fine root in enriched micro-sites is species dependent, and also affected by other factors, such as patch attributes (size and nutrients concentration), nutrients, and overall soil fertility. Beside root proliferation in nutrient enriched patches, plants can also adapt themselves to the heterogeneous soil environment by altering other root characteristics

  1. 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

  2. What a Dinner Party! Mechanisms and Functions of Interkingdom Signaling in Host-Pathogen Associations

    Melissa M. Kendall

    2016-05-01

    Full Text Available Chemical signaling between cells is an effective way to coordinate behavior within a community. Although cell-to-cell signaling has mostly been studied in single species, it is now appreciated that the sensing of chemical signals across kingdoms can be an important regulator of nutrient acquisition, virulence, and host defense. In this review, we focus on the role of interkingdom signaling in the interactions that occur between bacterial pathogens and their mammalian hosts. We discuss the quorum-sensing (QS systems and other mechanisms used by these bacteria to sense, respond to, and modulate host signals that include hormones, immune factors, and nutrients. We also describe cross talk between these signaling pathways and strategies used by the host to interfere with bacterial signaling, highlighting the complex bidirectional signaling networks that are established across kingdoms.

  3. Influence of nutrient delivery on gut structure and function.

    Bragg, L E; Thompson, J S; Rikkers, L F

    1991-01-01

    Food is an important stimulus for the growth of gastrointestinal mucosa. Gut structure is influenced by the route of nutrient administration, dietary composition and the availability of specific nutrients. The alterations in intestinal structure and function that occur when enteral nutrition is withheld suggests that the ingestion of food results in physiologic responses that are responsible for the maintenance of gut mass during the fed state. The mechanism of mucosal suppression that occurs during starvation, stress, and total parenteral nutrition is not completely understood but may involve the absence of luminal substrates, decreased pancreaticobiliary secretions and alterations in the endocrine or paracrine events that normally accompany eating, digestion, and absorption. Enterocytes prefer glutamine and ketone bodies as oxidative fuels, whereas colonocytes utilize short chain fatty acids. Although enteral delivery of nutrients is the preferred route for maintenance of intestinal mass, provision of specific nutrients and hormonal stimulation during parenteral alimentation has been shown to be important in maintaining mucosal structure and function. If not adequately maintained, the intestine becomes susceptible to a variety of injuries which may result in impaired ability to digest and absorb nutrients and loss of mucosal barrier function.

  4. 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...

  5. Cell cycle implication on nitrogen acquisition and synchronization in Thalassiosira weissflogii (Bacillariophyceae).

    Mocquet, Christophe; Sciandra, Antoine; Talec, Amélie; Bernard, Olivier

    2013-04-01

    The Michaelis-Menten model of nitrogen (N) acquisition, originally used to represent the effect of nutrient concentration on the phytoplankton uptake rate, is inadequate when other factors show temporal variations. Literature generally links diurnal oscillations of N acquisition to a response of the physiological status of microalgae to photon flux density (PFD) and substrate availability. This work describes how the cell cycle also constitutes a significant determinant of N acquisition and, when appropriate, assesses the impact of this property at the macroscopic level. For this purpose, we carried out continuous culture experiments with the diatom Thalassiosira weissflogii (Grunow) G. Fryxell & Hasle exposed to various conditions of light and N supply. The results revealed that a decrease in N acquisition occurred when a significant proportion of the population was in mitosis. This observation suggests that N acquisition is incompatible with mitosis and therefore that its acquisition rate is not constant during the cell cycle. In addition, environmental conditions, such as light and nutrient supply disrupt the cell cycle at the level of the individual cell, which impacts synchrony of the population.

  6. Theories of language acquisition.

    Vetter, H J; Howell, R W

    1971-03-01

    Prior to the advent of generative grammar, theoretical approaches to language development relied heavily upon the concepts ofdifferential reinforcement andimitation. Current studies of linguistic acquisition are largely dominated by the hypothesis that the child constructs his language on the basis of a primitive grammar which gradually evolves into a more complex grammar. This approach presupposes that the investigator does not impose his own grammatical rules on the utterances of the child; that the sound system of the child and the rules he employs to form sentences are to be described in their own terms, independently of the model provided by the adult linguistic community; and that there is a series of steps or stages through which the child passes on his way toward mastery of the adult grammar in his linguistic environment. This paper attempts to trace the development of human vocalization through prelinguistic stages to the development of what can be clearly recognized as language behavior, and then progresses to transitional phases in which the language of the child begins to approximate that of the adult model. In the view of the authors, the most challenging problems which confront theories of linguistic acquisition arise in seeking to account for structure of sound sequences, in the rules that enable the speaker to go from meaning to sound and which enable the listener to go from sound to meaning. The principal area of concern for the investigator, according to the authors, is the discovery of those rules at various stages of the learning process. The paper concludes with a return to the question of what constitutes an adequate theory of language ontogenesis. It is suggested that such a theory will have to be keyed to theories of cognitive development and will have to include and go beyond a theory which accounts for adult language competence and performance, since these represent only the terminal stage of linguistic ontogenesis.

  7. Modeling global nutrient export from watersheds

    Kroeze, C.; Bouwman, L.; Seitzinger, S.

    2012-01-01

    We describe how global models can be used to analyze past and future trends in nutrient export from watersheds and how such models can be used to analyze causes and effects of coastal eutrophication. Future nutrient inputs to coastal waters may be higher than today, and nutrient ratios may depart fr

  8. 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...

  9. Internal Control, Auditing, and the Automated Acquisitions System.

    Hawks, Carol Pitts

    1990-01-01

    Discusses issues and procedures involved in auditing the automated acquisitions system at Ohio State University Libraries. The audit process is explained, internal controls within the system are identified, general control mechanisms such as limited electronic access are discussed, and application control mechanisms that relate to specific…

  10. Rhizosphere priming: a nutrient perspective

    Feike Auke Dijkstra

    2013-07-01

    Full Text Available 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 in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P limited. Under P limitation, rhizodeposition may be used for mobilisation of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils.

  11. 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.

  12. Watching the brain during meaning acquisition.

    Mestres-Missé, Anna; Rodriguez-Fornells, Antoni; Münte, Thomas F

    2007-08-01

    Acquiring the meaning of a new word in a foreign language can be achieved either by rote memorizing or, similar to meaning acquisition during infancy, by extracting it from context. Little is known about the brain mechanisms involved in word learning. Here we demonstrate, using event-related brain potentials, the rapid development of a brain signature related to lexical and semantic processing during contextual word learning. Healthy volunteers engaged in a simple word-learning task were required to discover the meaning of a novel word from a context during silent reading. After 3 exposures, brain potentials to novel words in meaningful contexts were indistinguishable from real words, although this acquisition effect was not observed for novel words, for which sentence contexts allowed no meaning derivation. Furthermore, when the learned novel words were presented in isolation, an activation of their corresponding meaning was observed, although this process was slower than for real words.

  13. 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.

  14. 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.

  15. 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.

  16. Language Acquisition, Pidgins and Creoles.

    Wode, Henning

    1981-01-01

    Suggests that structural universals between different-based pidgins result from universal linguo-cognitive processing strategies which are employed in learning languages. Some of the strategies occur in all types of acquisition, and others are more applicable to L2 type acquisition. Past research is discussed, and some exemplary data are given.…

  17. Investment and Second Language Acquisition

    Pittaway, Daniel S.

    2004-01-01

    The article argues that Norton Peirce's (1995) concept of a language learner's investment should figure centrally in how instructors address the needs of adult learners in ESL classrooms. Investment is discussed in relation to second language acquisition research that addresses the role of social factors in second language acquisition. The article…

  18. 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.

  19. Universals of Second Language Acquisition.

    Eckman, Fred R., Ed.; And Others

    Works on second language acquisition theories, affective variables and communicative competence, and interlanguage were compiled as a result of a symposium on universals of second language acquisition at the University of Wisconsin, Milwaukee. The papers include: "On the Variability of Interlangauge Systems" (Elaine Tarone); "Memory, Learning, and…

  20. Markedness and Second Language Acquisition.

    Gil-Byeon, Ja

    1999-01-01

    Discusses whether markedness is at work in second-language acquisition in the same way it is in first-language acquisition when Korean speakers learn English as a second language and English speakers learn Korean as a second language. Results are discussed in terms of no access to universal grammar, partial access to universal grammar, and access…

  1. 48 CFR 873.105 - Acquisition planning.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Acquisition planning. 873.105 Section 873.105 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS DEPARTMENT... planning. (a) Acquisition planning is an indispensable component of the total acquisition process. (b)...

  2. 32 CFR 644.88 - Other acquisition.

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Other acquisition. 644.88 Section 644.88 National... HANDBOOK Acquisition Acquisition by Purchase, Donation, and Transfer § 644.88 Other acquisition. (a) Acquisition from other Federal departments and agencies—(1) Transfers. Transfers will be obtained from...

  3. 23 CFR 710.501 - Early acquisition.

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Early acquisition. 710.501 Section 710.501 Highways... REAL ESTATE Property Acquisition Alternatives § 710.501 Early acquisition. (a) Real property acquisition. The State may initiate acquisition of real property at any time it has the legal authority to...

  4. 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...

  5. 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...

  6. 48 CFR 3034.004 - Acquisition strategy.

    2010-10-01

    ... 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, HOMELAND... Acquisition strategy. See (HSAR) 48 CFR 3009.570 for policy applicable to acquisition strategies that...

  7. Nutrient Cycling in Piermont Marsh

    Reyes, N.; Gribbin, S.; Newton, R.; Diaz, K.; Laporte, N.; Trivino, G.; Ortega, J.; McKee, K.; Sambrotto, R.

    2011-12-01

    We investigate the cycling of nutrients through a brackish tidal wetland about 40 km north of Manhattan in the Hudson River estuary. As part of a long-term ecological study of Piermont Marsh, a NOAA reference wetland managed by the NY State DEC, we are measuring dissolved inorganic nutrients on the Marsh surface and its drainage channels. The marsh occupies 400 acres along the southwest corner of Haverstraw Bay with approximately 2 km frontage to the estuary. It is supplied with nutrient-rich water and drained primarily along several tidal creeks and the hundreds of rivulets that feed them. During most tidal cycles the silty berm bounding the marsh is not topped. Human influence in the marsh's surrounding area has had profound effects, one of the most fundamental of which has been the shift from native grass species, predominantly Spartina alterniflora, to an invasive genotype of common reed, Phragmites australis. Along with this shift there have been changes in the root bed, the effective marsh interior and berm heights, the hydroperiod and, as a result, the ability of the marsh to be utilized by various types of Hudson estuary fish. The vegetative shift is believed to be anthropogenic, but the connection is not well understood, and it is not known what role biogeochemical perturbations are playing. We present two field seasons of nitrate, phosphate and silicate measurements from Sparkill Creek, a freshwater stream draining the surrounding highlands constitutes the northern boundary, two tidally driven creeks transect the Marsh from West to East: the Crumkill and an unnamed creek we have dubbed the "Tidal", Ludlow Ditch, a no-longer-maintained drainage channel grading gently from the northern part of the marsh to the South terminates in a wide tidal outlet that is its southern boundary. Net tidal cycle fluxes and fluxes resulting from runoff events are presented. Deviations from Redfield ratios and limiting nutrients are analyzed. Piermont Marsh data is compared

  8. 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 ...

  9. 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 $\

  10. 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.

  11. Nutrient management strategies on Dutch dairy farms : an empirical analysis

    Ondersteijn, C.J.M.

    2002-01-01

    Key Words: MINAS; nitrogen surplus; phosphate surplus; nutrient efficiency; nutrient productivity; financial consequences; strategic management; perceived environmental uncertainty; nutrient management planning; dairy farming; The Netherlands.Agricultural nutrients are a possible pollutant of (groun

  12. 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....

  13. FOLIAR NUTRIENT CONTENTS AND FRUIT YIELD IN CUSTARD APPLE PROGENIES

    Paulo Sérgio Lima e Silva

    2009-01-01

    Full Text Available Foliar nutrient contents are evaluated in several fruit trees with many objectives. Leaf analysis constitutes a way of evaluating the nutritional requirements of crops. Due to the positive impact that fertilizers have on crop yields, researchers frequently try to evaluate the correlations between yield and foliar nutrient contents. This work's objective was to present fruit yields from the 4th to the 6th cropping seasons, evaluate foliar nutrient contents (on the 5th cropping season, and estimate the correlations between these two groups of traits for 20 half-sibling custard apple tree progenies. The progenies were evaluated in a random block design with five replicates and four plants per plot. One hundred leaves were collected from the middle third of the canopy (in height of each of four plants in each plot. The leaves were collected haphazardly, i.e., in a random manner, but without using a drawing mechanism. In the analysis of variance, the nutrient concentrations in the leaves from plants of each plot were represented by the average of four plants in the plot. Fruit yield in the various progenies did not depend on cropping season; progeny A4 was the most productive. No Spearman correlation was found between leaf nutrient concentrations and fruit yield. Increased nutrient concentrations in the leaves were progeny-dependent, i.e., with regard to Na (progenies FE5 and JG1, Ca (progeny A4, Mg (progeny SM7, N (progeny A3, P (progeny M, and K contents (progeny JG3. Spearman's correlation was negative between Na-Mg, Na-Ca, and Mg-P contents, and positive between Mg-Ca and N-K contents.

  14. Nutrientes minerales en alimentos industrializados

    Hernández F., Eloisa; Facultad de Farmacia y Bioquímica de la Universidad Nacional Mayor de San Marcos, Lima, Perú.; Quispe, Clara; Facultad de Farmacia y Bioquímica de la Universidad Nacional Mayor de San Marcos, Lima, Perú.; Alencastre M., Ana; Facultad de Farmacia y Bioquímica de la Universidad Nacional Mayor de San Marcos, Lima, Perú.

    2014-01-01

    Hasta el momento los alimentos industrializados que se consumen en nuestro medio aún no han sido estudiados por su contenido de nutrientes minerales. Se presenta los contenidos de fósforo, calcio, hierro, sodio, potasio, cobre y magnesio en 33 alimentos de procedencia nacional e importados. El 70% de estos alimentos son preferentemente consumidos por niños. Se ha empleado métodos oficiales de A.O.A.C.: para fósforo el método colorimétrico, los otros minerales mediante Absorción Atómica, Espec...

  15. Phosphorus physiological ecology and molecular mechanisms in marine phytoplankton.

    Lin, Senjie; Litaker, Richard Wayne; Sunda, William G

    2016-02-01

    Phosphorus (P) is an essential nutrient for marine phytoplankton and indeed all life forms. Current data show that P availability is growth-limiting in certain marine systems and can impact algal species composition. Available P occurs in marine waters as dissolved inorganic phosphate (primarily orthophosphate [Pi]) or as a myriad of dissolved organic phosphorus (DOP) compounds. Despite numerous studies on P physiology and ecology and increasing research on genomics in marine phytoplankton, there have been few attempts to synthesize information from these different disciplines. This paper is aimed to integrate the physiological and molecular information on the acquisition, utilization, and storage of P in marine phytoplankton and the strategies used by these organisms to acclimate and adapt to variations in P availability. Where applicable, we attempt to identify gaps in our current knowledge that warrant further research and examine possible metabolic pathways that might occur in phytoplankton from well-studied bacterial models. Physical and chemical limitations governing cellular P uptake are explored along with physiological and molecular mechanisms to adapt and acclimate to temporally and spatially varying P nutrient regimes. Topics covered include cellular Pi uptake and feedback regulation of uptake systems, enzymatic utilization of DOP, P acquisition by phagotrophy, P-limitation of phytoplankton growth in oceanic and coastal waters, and the role of P-limitation in regulating cell size and toxin levels in phytoplankton. Finally, we examine the role of P and other nutrients in the transition of phytoplankton communities from early succession species (diatoms) to late succession ones (e.g., dinoflagellates and haptophytes).

  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 TFP...

  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 TFP...

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Schizophrenia and second language acquisition.

    Bersudsky, Yuly; Fine, Jonathan; Gorjaltsan, Igor; Chen, Osnat; Walters, Joel

    2005-05-01

    Language acquisition involves brain processes that can be affected by lesions or dysfunctions in several brain systems and second language acquisition may depend on different brain substrates than first language acquisition in childhood. A total of 16 Russian immigrants to Israel, 8 diagnosed schizophrenics and 8 healthy immigrants, were compared. The primary data for this study were collected via sociolinguistic interviews. The two groups use language and learn language in very much the same way. Only exophoric reference and blocking revealed meaningful differences between the schizophrenics and healthy counterparts. This does not mean of course that schizophrenia does not induce language abnormalities. Our study focuses on those aspects of language that are typically difficult to acquire in second language acquisition. Despite the cognitive compromises in schizophrenia and the manifest atypicalities in language of speakers with schizophrenia, the process of acquiring a second language seems relatively unaffected by schizophrenia.

  3. 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...

  4. 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...

  5. Visceral perception: sensory transduction in visceral afferents and nutrients.

    Raybould, H E

    2002-07-01

    The possible mechanisms that may be involved in nutrient detection in the wall of the gastrointestinal tract are reviewed. There is strong functional and electrophysiological evidence that both intrinsic and extrinsic primary afferent neurones mediate mechano- and chemosensitive responses in the gastrointestinal tract. This review focuses on the extrinsic afferent pathways as these are the ones that convey information to the central nervous system which is clearly necessary for perception to occur.

  6. Language Acquisition and Language Learning

    蔡红

    2007-01-01

    Language is at the center of human life. This essay tries to seek similarities and differences between language acquisition and language learning from the theory achievements of some linguists. On this basis, it is pointed out that language acquisition is the effect of sub consciousness, while language learning is connected with conscious system. Thereby this paper analyzes the interaction between them and the influence on the present situation of foreign language teaching in China.

  7. Language Acquisition and Language Learning

    蔡红

    2007-01-01

    Language is at the center of human life.This essay tries to seek similarities and differences between language acquisition and language learning from the theory achievements of some linguists.On this basis,it is pointed out that language acquisition is the effect of sub consciousness,while language learning is connected with conscious system.Thereby this paper analyzes the interaction between them and the influence on the present situation of foreign language teaching in China.

  8. Ecological Theory of Language Acquisition

    Lacerda, Francisco; Klintfors, Eeva; Gustavsson, Lisa; Lagerkvist, Lisa; MARKLUND, ELLEN; Sundberg, Ulla

    2004-01-01

    This poster outlines an Ecological Theory of Language Acquisition (ETLA). The theory views the early phases of the language acquisition process as an emergent consequence of the interaction between the infant and its linguistic environment. The newborn infant is considered to be linguistically and phonetically naïve but endowed with the ability to register a wide range of multi-sensory inputs along with the ability to detect similarity between the multi-sensory stimuli it is exposed to. The i...

  9. Improving Tradecraft of Services Acquisition

    2015-08-01

    Logistics Management Services , Equipment Related Services , Electronics and Communication Services , Medical Services , and Facilities Related Defense AT&L...Acquisition University (DAU) Service Acquisition Process for standardization. This seven step, team-focused approach relies on market research...detailed in BBP 3.0. Training and Tools BBP 1.0 and 2.0 rightly noted that services are required and overseen by DoD personnel that often are not

  10. English Acquisition in Classroom Teaching

    周自强

    2013-01-01

    In the course of learning English in classroom, students cultivate their ability to use the language. But that ability does not mean they are able to acquire that language in a communicative way, because the acquisition of language in classroom is mainly for the purpose of learning. It starts and ends in a particular circumstance-the classroom. In that case, analyzed and dis-cussed is the universal feature of English acquisition in classroom and its effects on practical use respectively.

  11. Seasonal Variation of Nutrient Resorption in Nine Canopy Trees of a Wet Tropical Forest

    Wood, T. E.; Lawrence, D.

    2006-12-01

    Withdrawal of nutrients at the time of leaf abscission (nutrient resorption) is a nutrient conserving mechanism that could play an important role in stand-level nutrient economy. Currently data on nutrient resorption in wet tropical forests and on how this process varies temporally are sparse. We evaluated the N and P resorption efficiency of nine rain forest canopy tree species in both wet and dry season months. In addition, we measured short-term (bi-weekly) variation in nutrient resorption in the two dominant tree species, Pentaclethra macroloba and Laetia procera, over a 4-month period. We hypothesized that nutrient resorption would be more efficient during the dry season months and that resorption would be low during periods of high rainfall. Contrary to expectations, P resorption efficiency was higher in the wet season for four of the nine canopy tree species, while N resorption did not differ seasonally. The low dry season P resorption efficiency found in this study may be the result of drought stress during short periods of low rainfall, leading to incomplete nutrient resorption from senescing leaves. Nutrient resorption also varied significantly over the short-term. Both P and N resorption efficiency increased in P. macroloba and L. procera as the wet season progressed. The variability in resorption was not related to rainfall or temperature. Instead, the senesced leaf concentrations were a simple proportion of green leaf nutrient concentrations, with short punctuated periods of high resorption efficiency that may be reflective of species-specific phenological events, such as fruit and leaf production. The different timing of the seasonal increase in nutrient resorption between L. procera and P. macroloba supports this hypothesis, deserving of further study.

  12. Manganese acquisition by Lactobacillus plantarum

    Archibald, F.S.; Duong, M.N.

    1984-04-01

    Lactobacillus plantarum has an unusually high Mn(II) requirement for growth and accumulated over 30 mM intracellular Mn(II). The acquisition of Mn(II) by L. plantarum occurred via a specific active transport system powered by the transmembrane proton gradient. The Mn(II) uptake system has a K/sub m/ of 0.2 ..mu..M and a V/sub max/ of 24 nmol mg/sup -1/ of protein min/sup -1/. Above a medium Mn(II) concentration of 200 ..mu..M, the intracellular Mn(II) level was independent of the medium Mn(II) and unresponsive to oxygen stresses but was reduced by phosphate limitation. At a pH of 5.5, citrate, isocitrate, and cis-aconitate effectively promoted MN(II) uptake, although measurable levels of 1,5-(/sup 14/C)citrate were not accumulated. When cells were presented with equimolar Mn(II) and Cd(II), Cd(II) was preferentially taken up by the Mn(II) transport system. Both Mn(II) and Cd(II) uptake were greatly increased by Mn(II) starvation. Mn(II) uptake by Mn(II)-starved cells was subject to a negative feedback regulatory mechanism functioning less than 1 min after exposure of the cells to Mn(II) and independent of protein synthesis. When presented with a relatively large amount of exogenous Mn(II), Mn(II)-starved cells exhibited a measurable efflux of their internal Mn(II), but the rate was only a small fraction of the maximal Mn(II) uptake rate.

  13. Neural regulation of intestinal nutrient absorption.

    Mourad, Fadi H; Saadé, Nayef E

    2011-10-01

    The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function.

  14. Nutrients, satiety, and control of energy intake.

    Tremblay, Angelo; Bellisle, France

    2015-10-01

    In the context of the worldwide epidemic of obesity affecting men and women of all ages, it is important to understand the mechanisms that control human appetite, particularly those that allow the adjustment of energy intake to energy needs. Satiety is one important psycho-biological mechanism whose function is to inhibit intake following the ingestion of a food or a beverage. According to the classical theories of appetite control, satiety is influenced by macronutrient intake and/or metabolism. Satiety also seems to be modified by micronutrients, non-nutrients, and some bioactive food constituents. Under optimal conditions, satiety should be well connected with hunger and satiation in a way that spontaneously leads to a close match between energy intake and expenditures. However, the current obesity epidemic suggests that dysfunctions often affect satiety and energy intake. In this regard, this paper presents a conceptual integration that hopefully will help health professionals address satiety issues and provide the public with informed advice to facilitate appetite control.

  15. 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)

  16. Control of microorganisms in flowing nutrient solutions.

    Evans, R D

    1994-11-01

    Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

  17. Nutrient salvaging and metabolism by the intracellular pathogen Legionella pneumophila.

    Fonseca, Maris V; Swanson, Michele S

    2014-01-01

    The Gram-negative bacterium Legionella pneumophila is ubiquitous in freshwater environments as a free-swimming organism, resident of biofilms, or parasite of protozoa. If the bacterium is aerosolized and inhaled by a susceptible human host, it can infect alveolar macrophages and cause a severe pneumonia known as Legionnaires' disease. A sophisticated cell differentiation program equips L. pneumophila to persist in both extracellular and intracellular niches. During its life cycle, L. pneumophila alternates between at least two distinct forms: a transmissive form equipped to infect host cells and evade lysosomal degradation, and a replicative form that multiplies within a phagosomal compartment that it has retooled to its advantage. The efficient changeover between transmissive and replicative states is fundamental to L. pneumophila's fitness as an intracellular pathogen. The transmission and replication programs of L. pneumophila are governed by a number of metabolic cues that signal whether conditions are favorable for replication or instead trigger escape from a spent host. Several lines of experimental evidence gathered over the past decade establish strong links between metabolism, cellular differentiation, and virulence of L. pneumophila. Herein, we focus on current knowledge of the metabolic components employed by intracellular L. pneumophila for cell differentiation, nutrient salvaging and utilization of host factors. Specifically, we highlight the metabolic cues that are coupled to bacterial differentiation, nutrient acquisition systems, and the strategies utilized by L. pneumophila to exploit host metabolites for intracellular replication.

  18. 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.

  19. Research Progress of Soil Properties in Tea Gardens and the Absorption and Translocation Mechanisms of Nutrients and Other Elements in Tea Plant%茶园土壤性状及茶树营养元素吸收、转运机制研究进展

    刘美雅; 伊晓云; 石元值; 马立锋; 阮建云

    2015-01-01

    优质安全的茶叶离不开养分条件、环境安全和茶园的土、水、肥的管理。本文在茶园土壤、茶树养分功能和分子营养机制、茶树施肥技术、茶园土壤重金属及茶树累积特点和机制等方面,对近五年来国内外的研究进展进行了综述。在茶园土壤研究方面,除了关注植茶后茶园土壤有机质变化特点外,茶园碳储量在全球碳循环中所起的重要作用也引起了人们的重视,同时分子生物学技术也开始应用于茶园土壤微生物种群数量和演变的研究,并在茶园土壤质量评价、土壤酸化原因以及应用生物质改良酸化茶园土壤等方面取得了一定进展。在茶树养分功能和调控技术方面,对主要营养元素氮、磷、钾等的营养功能及其在茶叶品质成分代谢中的作用和茶树吸收特性等有了更深入的认识,在茶树养分转运子基因克隆、氮营养分子生理机制、抗环境胁迫的分子基础等方面的研究逐渐深入,在机械施肥、水肥一体化、控释肥施用等技术研究方面取得较大进展,施肥的环境效应特别是温室气体排放影响成为近年的研究热点。伴随着对食品安全问题的关注,茶叶产地土壤重金属和稀土等的安全状况、茶树累积特点等方面的研究也取得一定进展。%The soil conditions of tea plantations as well as the management of water and fertilizers are requisites for tea plant growth and quality construction. This paper reviewed the research progresses in the recent five years on the topics of the dynamics of soil properties of tea gardens, the functions of nutrients associating with the metabolism of tea quality related components and the underneath molecular mechanisms, the management technologies of nutrition, heavy metals and rare earth elements in tea soils and their accumulation in plants. In addition to the works of the dynamics of organic matter in tea soil following

  20. Genetic influences on the acquisition and inhibition of fear.

    Wendt, Julia; Neubert, Jörg; Lindner, Katja; Ernst, Florian D; Homuth, Georg; Weike, Almut I; Hamm, Alfons O

    2015-12-01

    As a variant of the Pavlovian fear conditioning paradigm the conditional discrimination design allows for a detailed investigation of fear acquisition and fear inhibition. Measuring fear-potentiated startle responses, we investigated the influence of two genetic polymorphisms (5-HTTLPR and COMT Val(158)Met) on fear acquisition and fear inhibition which are considered to be critical mechanisms for the etiology and maintenance of anxiety disorders. 5-HTTLPR s-allele carriers showed a more stable potentiation of the startle response during fear acquisition. Homozygous COMT Met-allele carriers, which had demonstrated delayed extinction in previous investigations, show deficient fear inhibition in presence of a learned safety signal. Thus, our results provide further evidence that 5-HTTLPR and COMT Val(158)Met genotypes influence the vulnerability for the development of anxiety disorders via different mechanisms.

  1. Smartphone forensics & data acquisition

    Παχύγιαννης, Παναγιώτης

    2015-01-01

    This study, both on a theoretical and a practical level, addresses the field of Digital Forensics as far as mobile devices are concerned and specifically the safety of Smartphone devices, which use the operating system of Androids (Mobile Android OS). Smartphone devices are evolving rapidly and their technology and usability outweigh their predecessors. However their main weakness is security. For the operation of Smartphone devices the activation of defense mechanisms is required in order...

  2. Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia.

    van der Wulp, Simon A; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J

    2016-09-30

    The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377m(3)s(-1) entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174tons and 14 to 60tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics.

  3. 外部知识获取影响企业创新绩效的作用机理%Effect Mechanism of External Knowledge Acquisition on Enterprise's Innovation Performance

    秦志华; 王冬冬; 赵婧

    2014-01-01

    从外部知识需要通过企业内部实践才能加以利用这一思路出发,基于中国489家大中型企业的调查数据,运用SPSS21.0软件实证探讨了内部沟通和创新激励对外部知识向创新绩效转化的影响机理。层级回归结果显示:外部知识获取对企业创新绩效的提升具有显著作用,内部沟通和创新激励在上述关系中起部分中介作用。%This paper ,based on the perspective that external knowledge needs to be internalized by internal firm practices ,explores the effect of intra‐firm communication and innovation incentive on the transformation from external knowledge to firm innovation performance by using 489 large and medium‐sized companies in China and SPSS21 .0 software .The hierarchical regression results show as follows :external knowledge ac‐quisition has the positive impact on firm's innovation performance ;intra‐firm communication and innovation incentive moderate the relationship between external knowledge acquisition and firms innovation performance .

  4. 48 CFR 7.402 - Acquisition methods.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Acquisition methods. 7.402... ACQUISITION PLANNING Equipment Lease or Purchase 7.402 Acquisition methods. (a) Purchase method. (1) Generally, the purchase method is appropriate if the equipment will be used beyond the point in time...

  5. Sustaining an Acquisition-based Growth Strategy

    Henningsson, Stefan; Toppenberg, Gustav; Shanks, Graeme

    complementarity, c) directing and governing the integration process, and d) post-acquisition evaluation of the achieved integration and proposing ways forward. Using the EA capability in the acquisition process improves Cisco’s ability to rapidly capture value from its acquisitions and to sustain its acquisition......-based growth strategy over time....

  6. 14 CFR 151.73 - Land acquisition.

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Land acquisition. 151.73 Section 151.73... FEDERAL AID TO AIRPORTS Project Programming Standards § 151.73 Land acquisition. (a) The acquisition of... forth typical eligible and ineligible items of land acquisition as covered by this section....

  7. 32 CFR 644.7 - Acquisition lines.

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Acquisition lines. 644.7 Section 644.7 National... HANDBOOK Project Planning Civil Works § 644.7 Acquisition lines. (a) Tentative acquisition lines. As indicated in § 644.6(c)(1)(iii)(K), tentative acquisition lines are shown on maps which are part of the...

  8. Acquisition in USTRANSCOM: An Organizational Assessment

    2009-12-01

    CRAF Civil Reserve Air Fleet DAPA Defense Acquisition Performance Assessment DAR Defense Acquisition Regulation DAS Defense Acquisition...ENVIRONMENT The current Defense Acquisition Environment consists of a triad between Congress, the Executive Branch, and Industry. The DoD Program...Manager (PM) fits directly in the middle of this triad and is constantly receiving and delivering information to the entities mentioned above

  9. 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.

  10. Interdependence of nutrient metabolism and the circadian clock system: Importance for metabolic health

    Aleix Ribas-Latre

    2016-03-01

    Major conclusions: Targeted use of specific nutrients based on chronotype has the potential for immense clinical utility in the future. Macronutrients and micronutrients have the ability to function as zeitgebers for the clock by activating or modulating specific clock proteins or accessory proteins (such as nuclear receptors. Circadian clock control by nutrients can be tissue-specific. With a better understanding of the mechanisms that support nutrient-induced circadian control in specific tissues, human chronotype and SNP information might eventually be used to tailor nutritional regimens for metabolic disease treatment and thus be an important part of personalized medicine's future.

  11. 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.

  12. 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.

  13. Acquisition Pros Keep the Gears Moving

    2015-06-01

    program folks and team members throughout the entire acquisition process. Acquisition Reform Part of acquisition reform includes resupplying the...Acquisition requires us to be critical thinkers (remem- ber to be inquisitive) and to be self-motivated professionals. All customers want to feel they are...involvement and open dialogue with the customer and other members of the acquisition team increase the chances for an execution success because the

  14. Nutrient Acquisition: The Generation of Bioactive Vitamin B12 by Microalgae.

    Grossman, Arthur

    2016-04-25

    Many microalgae acquire vitamin B12 from marine prokaryotes. A new study demonstrates that vitamin B12 is synthesized by planktonic cyanobacteria as pseudocobalamin, a form not bioactive in microalgae. However, some microalgae can remodel pseudocobalamin to the active cobalamin form, adding complexity to our assessment of active vitamin B12 in the environment.

  15. 77 FR 181 - Federal Acquisition Regulation; Federal Acquisition Circular 2005-55; Introduction

    2012-01-03

    ... Space Administration 48 CFR Chapter 1 Federal Acquisition Regulation; Final Rules #0;#0;Federal Register... Acquisition Regulation; Federal Acquisition Circular 2005-55; Introduction AGENCIES: Department of Defense (Do... Acquisition Regulation (FAR) rules agreed to by DoD, GSA, and NASA in this Federal Acquisition Circular...

  16. Fluid dynamic constraints on resource acquisition in small pelagic organisms

    Kiørboe, Thomas

    2016-01-01

    by the application of formal fluid physics. Here, I examine resource acquisition mechanisms in small aquatic organisms, ranging from uptake of dissolved molecules to feeding on suspended particulate prey, and examine how organism behaviors and morphologies may be shaped by the often non-intuitive small-scale fluid...

  17. Some aspects of interactions between heavy metals and plant mineral nutrients

    Anna Siedlecka

    2014-01-01

    Heavy metals are aggresive environmental pollutants. They are easily taken up by plants and they are strong stess factors for plant metabolism. Heavy metals influence includes also disturbances in plant mineral nutrition by competition with other nutrients. Typical symptoms of heavy metals toxicity are often similar or even the same like symptoms of some essential nutrients deficiency. The aim of this paper is to discuss mechanisms of some heavy metals uptake and possible ways of their influe...

  18. Parametric Variation in Acquisition and Diachronic Change: A Response to the Commentaries

    Meisel, Jurgen M.

    2011-01-01

    The starting hypothesis of the keynote article (KA) is that language acquisition plays an essential role in processes leading to grammatical change. Consequently, a minimal requirement, to be met by explanations of diachronic change is that they rely on mechanisms which are operative in acquisition. The KA is therefore an appeal for…

  19. Linguistic Diversity in First Language Acquisition Research: Moving beyond the Challenges

    Kelly, Barbara F.; Forshaw, William; Nordlinger, Rachel; Wigglesworth, Gillian

    2015-01-01

    The field of first language acquisition (FLA) needs to take into account data from the broadest typological array of languages and language-learning environments if it is to identify potential universals in child language development, and how these interact with socio-cultural mechanisms of acquisition. Yet undertaking FLA research in remote…

  20. Closed-Cycle Nutrient Supply For Hydroponics

    Schwartzkopf, Steven H.

    1991-01-01

    Hydroponic system controls composition and feed rate of nutrient solution and recovers and recycles excess solution. Uses air pressure on bladders to transfer aqueous nutrient solution. Measures and adjusts composition of solution before it goes to hydroponic chamber. Eventually returns excess solution to one of tanks. Designed to operate in microgravity, also adaptable to hydroponic plant-growing systems on Earth.

  1. Systematically enhanced subarctic Pacific stratification and nutrient utilization during glacials

    Knudson, K. P.; Ravelo, A. C.

    2015-12-01

    The modern subarctic North Pacific is characterized as a high-nitrate, low-chlorophyll (HNLC) area, but evidence for increased nutrient utilization during the last glacial indicates that this region is highly dynamic. As such, this HNLC area is of particular interest in regard to understanding changes in the biological pump and carbon sequestration and predicting how biogeochemical processes will influence, or be influenced by, future climate change. While it has been suggested that changes in iron supply and/or ocean stratification could explain fluctuations in nutrient utilization and productivity in the subarctic Pacific, short records of nutrient utilization have previously hindered the evaluation of these potential mechanisms over long timescales. Here we present new, high-resolution records of bulk sediment δ15N from 0-1.2 Ma from Integrated Ocean Drilling Program Exp. 323 Site U1342, which are used to calculate Δδ15N (U1342 δ15Nbulk - ODP Site 1012 δ15Nbulk) as a nitrate utilization proxy. The unprecedented length and resolution of this new record allows us, for the first time, to determine orbital-scale systematic behavior in subarctic Pacific nutrient utilization over many glacial/interglacial cycles. Spectral analyses demonstrate that enhanced nutrient utilization was paced by climate on Milankovitch orbital cycles since the Mid-Pleistocene Transition (MPT; ~800 ka). Nitrate utilization maxima is statistically correlated with glacial maxima and enhanced dust/iron availability (represented by existing records of EPICA ice core dust, Southern Pacific Ocean sediment iron, and China loess) but shows low correlation to primary productivity, suggesting that stratification has systematically exerted an important control on subarctic Pacific nutrient utilization since the MPT. These findings imply that the presence of iron helped to change the region into a nitrate-limited, rather than iron-limited, region during glacials and that stratification, which

  2. A lysosome-centered view of nutrient homeostasis.

    Mony, Vinod K; Benjamin, Shawna; O'Rourke, Eyleen J

    2016-01-01

    Lysosomes are highly acidic cellular organelles traditionally viewed as sacs of enzymes involved in digesting extracellular or intracellular macromolecules for the regeneration of basic building blocks, cellular housekeeping, or pathogen degradation. Bound by a single lipid bilayer, lysosomes receive their substrates by fusing with endosomes or autophagosomes, or through specialized translocation mechanisms such as chaperone-mediated autophagy or microautophagy. Lysosomes degrade their substrates using up to 60 different soluble hydrolases and release their products either to the cytosol through poorly defined exporting and efflux mechanisms or to the extracellular space by fusing with the plasma membrane. However, it is becoming evident that the role of the lysosome in nutrient homeostasis goes beyond the disposal of waste or the recycling of building blocks. The lysosome is emerging as a signaling hub that can integrate and relay external and internal nutritional information to promote cellular and organismal homeostasis, as well as a major contributor to the processing of energy-dense molecules like glycogen and triglycerides. Here we describe the current knowledge of the nutrient signaling pathways governing lysosomal function, the role of the lysosome in nutrient mobilization, and how lysosomes signal other organelles, distant tissues, and even themselves to ensure energy homeostasis in spite of fluctuations in energy intake. At the same time, we highlight the value of genomics approaches to the past and future discoveries of how the lysosome simultaneously executes and controls cellular homeostasis.

  3. Dissolved nutrient retention dynamics in river networks: A modeling investigation of transient flows and scale effects

    Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu; Basu, Nandita B.; Li, Hong-Yi; Wang, Shao-Wen

    2012-06-01

    We have used a dynamic hydrologic network model, coupled with a transient storage zone solute transport model, to simulate dissolved nutrient retention processes during transient flow events at the channel network scale. We explored several scenarios with a combination of rainfall variability, and biological and geomorphic characteristics of the catchment, to understand the dominant factors that control the transport of dissolved nutrients (e.g., nitrate) along channel networks. While much experimental work has focused on studying nutrient retention during base flow periods in headwater streams, our model-based theoretical analyses, for the given parameter combinations used, suggest that high-flow periods can contribute substantially to overall nutrient retention, and that bulk nutrient retention is greater in larger rivers compared to headwaters. The relative efficiencies of nutrient retention during high- and low-flow periods vary due to changes in the relative sizes of the main channel and transient storage zones, as well as due to differences in the relative strengths of the various nutrient retention mechanisms operating in both zones. Our results also indicate that nutrient retention efficiency at all spatial scales of observation has strong dependence on within-year variability of streamflow (e.g., frequency and duration of high and low flows), as well as on the relative magnitudes of the coefficients that govern biogeochemical uptake processes: the more variable the streamflow, the greater the export of nutrients. Despite limitations of the model parameterizations, our results suggest that increased attention must be paid to field observations of the interactions between process hydrology and nutrient transport and reaction processes at a range of scales to assist with extrapolation of understandings and estimates gained from site-specific studies to ungauged basins across gradients in climate, human impacts, and landscape characteristics.

  4. Computational models of syntactic acquisition.

    Yang, Charles

    2012-03-01

    The computational approach to syntactic acquisition can be fruitfully pursued by integrating results and perspectives from computer science, linguistics, and developmental psychology. In this article, we first review some key results in computational learning theory and their implications for language acquisition. We then turn to examine specific learning models, some of which exploit distributional information in the input while others rely on a constrained space of hypotheses, yet both approaches share a common set of characteristics to overcome the learning problem. We conclude with a discussion of how computational models connects with the empirical study of child grammar, making the case for computationally tractable, psychologically plausible and developmentally realistic models of acquisition. WIREs Cogn Sci 2012, 3:205-213. doi: 10.1002/wcs.1154 For further resources related to this article, please visit the WIREs website.

  5. Nutrient utilization with and without recycling within farming systems

    Seuri, Pentti

    2002-01-01

    Nutrient balances are used as a measure of nutrient utilization. It is, however, difficult to compare the nutrient utilization between farms, especially if their production systems are different. New analytical tools and methods of interpreting nutrient utilization based on nutrient balances are introduced.

  6. Current Status and Advancements in Research of Plantation Nutrient Cycling

    LI Run; ZHANG Changshun; SUN Yongyu

    2006-01-01

    This paper introduces concepts and current research status of plantation nutrients cyclings, and analyzes main contents of plantation nutrients cycling as nutrients contents, accumulation and distribution of nutrients elements, understory species and forest litter. At the same time, the paper summarizes the problems in plantation nutrients cycling and its prospects.

  7. Complex System Governance for Acquisition

    2016-04-30

    includes acquisition. In this paper, after an introduction of our perception of the problem space, we outline the nine essential meta functions and...implications for the wider acquisition field. ^Åèìáëáíáçå=oÉëÉ~êÅÜ=mêçÖê~ãW= `êÉ~íáåÖ=póåÉêÖó=Ñçê=fåÑçêãÉÇ=`Ü~åÖÉ= - 197 - Introduction As...capital markets : Wall Street and the Pentagon. An annotated brief. Boudreau, M. (2007). Acoustic rapid COTS insertion: A case study in modular open

  8. Motivation in Second Language Acquisition

    GAO Ya

    2015-01-01

    Second language acquisition is a complex process which involves various factors. The factors can be put into two cate⁃gories:social factors and learner factors. Each category includes a number of factors. The factors such as motivation, age, learning strategies and others such as personality, aptitude are also mutually related. Among all of those factors, motivation plays a very im⁃portant role in the second language acquisition. In this essay, the author will discuss the key factors that affect the outcome of the process.

  9. 76 FR 30362 - Federal Acquisition Regulation; Submission for OMB Review; Acquisition of Helium

    2011-05-25

    ... ADMINISTRATION [OMB Control No. 9000-0113; Docket 2011-0079; Sequence 5] Federal Acquisition Regulation; Submission for OMB Review; Acquisition of Helium AGENCY: Department of Defense (DOD), General Services... approved information collection requirement concerning acquisition of helium. Public comments...

  10. New actions for old nutrients

    Carlos Lifschitz

    2012-06-01

    Full Text Available The purpose of this review is to present information regarding new effects for certain nutrients other than those traditionally known. Zinc has been found to prevent and reduce the duration of common colds. In developing countries, zinc has been shown to reduce the duration and severity of diarrhea and even decrease relapses. Iron supplementation in iron defi cient children, has been shown to improve several aspects of brain function. In studies where iron was given to the mother, 3 of 5 randomized, controlled trials showed a benefi cial effect of iron supplementation on the Psychomotor Development Index at some time points, whereas 2 did not. The chances for infants supplemented with docosahexaenoic acid in the fi rst year of life of having at least 1 event of allergic manifestation or upper respiratory infection or at least 1 event of wheezing/asthma, wheezing/asthma/atopic dermatitis, any allergy, or an upper respiratory tract infection during the fi rst 3 years of life were signifi cantly lower than in the non supplemented group. Epidemiological studies have established a relationship between low levels of serum vitamin D and reduced lung function in healthy adults and asthma onset and severity in children. There was a trend for an independent association between higher levels of maternal circulating 25(OHD3 levels in pregnancy and decreased odds of lower respiratory tract infections in offspring.

  11. Effects of nutrient intake on sympathoadrenal activity and thermogenic mechanisms

    Astrup, A V; Christensen, N J; Simonsen, L

    1990-01-01

    Ingestion of carbohydrate results in a diphasic activation of the sympathoadrenal system. One component is an insulin-mediated activation of the sympathetic nervous system (SNS). This activation is partly a haemodynamic reflex, but it may cause a weak thermogenic effect via beta 1-adrenoceptors...... the physiological threshold for thermogenic effect. The target is mainly skeletal muscle where thermogenesis is stimulated via beta 2-adrenoceptors. Also the basal metabolic rate and the thermogenic responses to cold and heat exposure, mental stress and exercise, have facultative components. Inhibition...

  12. Control of Breast Carcinoma Angiogenesis by Nutrient Stress Mechanisms

    2004-08-01

    Wasa M, Souba WW, Abcouwer SF. Regulation of glutamine synthetase dihydroguaiaretic acid and in vitro cytotoxie effects on cancer cells. Cancer Lett...Abcouwer SF: Regulation of androgen-independent prostate cancer. Clinical Cancer Research glutamine synthetase in human breast carcinoma cells and 2000

  13. Mechanisms of deterioration of nutrients. [of freeze dried foods

    Karel, M.; Flink, J. M.

    1976-01-01

    Methods which produce freeze dried foods of improved quality were examined with emphasis on storage stability. Specific topics discussed include: microstructure of freeze dried systems, investigation of structural changes in freeze dried systems, artificial food matrices, osmotic preconcentration to yield improved quality freeze dried fruits, and storage stability of osmotically preconcentrated freeze dried fruits.

  14. Degradation of Soil Nutrients in Southeast China

    2000-01-01

    A total of 2190 soil nutrient data in the Second National Soil Survey of China were collected to assess the degradation of soil nutrients in the hilly region of Southeast China. The definition of soil nutrient degradation is suggested firstly, then the evaluation criteria are set up and the current status of degradation of red soil and latosol is assessed. The percentages of areas in four grades of soil nutrient degradation, i.e., slightly deficient, medium deficient, severely deficient and extremely deficient, were 21.3%, 43.3%, 16.2% and 3.0% for soil total N; 0.7%, 6.4%, 16.7% and 76.2% for soil available P; and 25.4%, 26.3%, 8.6% and 5.0% for soil available K, respectively. The severity of soil nutrient degradation was in the order of P > N > K. The major factors leading to the degradation of soil nutrients in quantity include soil erosion, leaching and the consumption by crops. And the principal factor affecting the degradation of soil nutrients in availability is the fixation of N, P and K, especially the fixation of phosphorus. The average amount of P fixed by soils is 408 mg kg-1, and upland soils can fix more P than paddy soils.

  15. Nutrient Lossed in Soils on Loess Plateau

    PENGLIN; WANGJI-ZENG; 等

    1995-01-01

    The soil nutrient losses due to excessive soil loss on Loess Plateau were studied by means of runoff plots and systematical determination of soil nutrients both in sediments and runoff.The results show that the amounts of nutrient losses depended on the amounts of ersoion sediments.Along with sediment,11-197kg nitrogen/hectare and 9-174kg phosphorus/hectare were lost,accounting for 92.46-99.47 percent of the total amount of nitrogen loss and 99.85-99.99 percent of the total amount of phosphorus loss respectively.The nutrient losses,very small in runoff,were mainly attributed to erosion of a few rainstorms during a year.The nutrient level in sediment was mostly higher than that in the original soil.Planting grass evidently redued the losses of soil nutrients.The N level was lower in runoff than in rainfall so that the N loss from runoff could be made up by rainfall.Fertilizer application to crops raised the nutrient level in runoff.

  16. Data Acquisition for Modular Biometric Monitoring System

    Chmiel, Alan J. (Inventor); Humphreys, Bradley T. (Inventor); Grodsinsky, Carlos M. (Inventor)

    2014-01-01

    A modular system for acquiring biometric data includes a plurality of data acquisition modules configured to sample biometric data from at least one respective input channel at a data acquisition rate. A representation of the sampled biometric data is stored in memory of each of the plurality of data acquisition modules. A central control system is in communication with each of the plurality of data acquisition modules through a bus. The central control system is configured to collect data asynchronously, via the bus, from the memory of the plurality of data acquisition modules according to a relative fullness of the memory of the plurality of data acquisition modules.

  17. Phosphate addition enhanced soil inorganic nutrients to a large extent in three tropical forests.

    Zhu, Feifei; Lu, Xiankai; Liu, Lei; Mo, Jiangming

    2015-01-21

    Elevated nitrogen (N) deposition may constrain soil phosphorus (P) and base cation availability in tropical forests, for which limited evidence have yet been available. In this study, we reported responses of soil inorganic nutrients to full factorial N and P treatments in three tropical forests different in initial soil N status (N-saturated old-growth forest and two less-N-rich younger forests). Responses of microbial biomass, annual litterfall production and nutrient input were also monitored. Results showed that N treatments decreased soil inorganic nutrients (except N) in all three forests, but the underlying mechanisms varied depending on forests: through inhibition on litter decomposition in the old-growth forest and through Al(3+) replacement of Ca(2+) in the two younger forests. In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively. These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return. Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests.

  18. The role of placental nutrient sensing in maternal-fetal resource allocation.

    Díaz, Paula; Powell, Theresa L; Jansson, Thomas

    2014-10-01

    The placenta mediates maternal-fetal exchange and has historically been regarded as a passive conduit for nutrients. However, emerging evidence suggests that the placenta actively responds to nutritional and metabolic signals from the mother and the fetus. We propose that the placenta integrates a multitude of maternal and fetal nutritional cues with information from intrinsic nutrient-sensing signaling pathways to match fetal demand with maternal supply by regulating maternal physiology, placental growth, and nutrient transport. This process, which we have called placental nutrient sensing, ensures optimal allocation of resources between the mother and the fetus to maximize the chances for propagation of parental genes without jeopardizing maternal health. We suggest that these mechanisms have evolved because of the evolutionary pressures of maternal undernutrition, which result in decreased placental growth and down-regulation of nutrient transporters, thereby limiting fetal growth to ensure maternal survival. These regulatory loops may also function in response to maternal overnutrition, leading to increased placental growth and nutrient transport in cases of maternal obesity or gestational diabetes. Thus, placental nutrient sensing modulates maternal-fetal resource allocation to increase the likelihood of reproductive success. This model implies that the placenta plays a critical role in mediating fetal programming and determining lifelong health.

  19. The Role of Placental Nutrient Sensing in Maternal-Fetal Resource Allocation1

    Díaz, Paula; Powell, Theresa L.; Jansson, Thomas

    2014-01-01

    ABSTRACT The placenta mediates maternal-fetal exchange and has historically been regarded as a passive conduit for nutrients. However, emerging evidence suggests that the placenta actively responds to nutritional and metabolic signals from the mother and the fetus. We propose that the placenta integrates a multitude of maternal and fetal nutritional cues with information from intrinsic nutrient-sensing signaling pathways to match fetal demand with maternal supply by regulating maternal physiology, placental growth, and nutrient transport. This process, which we have called placental nutrient sensing, ensures optimal allocation of resources between the mother and the fetus to maximize the chances for propagation of parental genes without jeopardizing maternal health. We suggest that these mechanisms have evolved because of the evolutionary pressures of maternal undernutrition, which result in decreased placental growth and down-regulation of nutrient transporters, thereby limiting fetal growth to ensure maternal survival. These regulatory loops may also function in response to maternal overnutrition, leading to increased placental growth and nutrient transport in cases of maternal obesity or gestational diabetes. Thus, placental nutrient sensing modulates maternal-fetal resource allocation to increase the likelihood of reproductive success. This model implies that the placenta plays a critical role in mediating fetal programming and determining lifelong health. PMID:25122064

  20. Input and Second Language Acquisition

    周笑盈

    2011-01-01

    The behaviorist, the mentalist and the interactionist have different emphases on the role input in Second Language Acquisition. In order to protrude the importance of second language teaching, it is indispensible to discuss the characteristics of input and to explore its effects.

  1. The SINQ data acquisition environment

    Maden, D. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    The data acquisition environment for the neutron scattering instruments supported by LNS at SINQ is described. The intention is to provide future users with the necessary background to the computing facilities on site rather than to present a user manual for the on-line system. (author) 5 figs., 6 refs.

  2. Survey design for blended acquisition

    Blacquière, G.; Berkhout, A.J.; Verschuur, D.J.

    2009-01-01

    When designing an acquisition geometry for the case of source blending, it is important that the blended source arrays are capable of transmitting a wavefield with a large spatial and temporal bandwidth: the wavefield must be incoherent. We call this incoherent shooting. Furthermore, the array must

  3. Defense Acquisitions Acronyms and Terms

    2012-12-01

    AMSDL Acquisition Management Systems Data List ANSI American National Standards Institute AO Operational Availability AoA Analysis of...Erasable Programmable Read-Only Memory EFA Engineering Field Activity EFD Engineering Field Division EI Enterprise Integration EIT External...Ground Intercept Point GNP Gross National Product GOCO Government-Owned, Contractor-Operated (Facility) GOGO Government-Owned, Government

  4. Soviet Studies in Language Acquisition

    Smith, Paul R., Jr.

    1973-01-01

    Article surveys the special theories and empirical studies of language acquisition carried out by Soviet psychologists, especially in the period since 1950. The basic principles of materialism, historicism and social reference characteristic of Soviet Marxist psychology are placed in contrast to certain current tendencies in American linguistics.…

  5. Employment effects of foreign acquisition

    Bandick, Roger; Karpaty, Patrik

    2011-01-01

    This paper investigates the employment effects of foreign acquisitions in acquired firms in Swedish manufacturing during the 1990s; a period characterized by a dramatic increase in foreign ownership. We find some evidence of positive employment effects in acquired firms and it seems...... by foreign MNEs, but not in acquired Swedish MNEs....

  6. More Mergers,More Acquisitions

    LAN XINZHEN

    2010-01-01

    @@ A new round of corporate mergers and acquisitions(M&As)is on the way.On September 6,the State Council announced that it would require companies in the automobile,iron and steel,cement,machinery manufacturing,electrolytic aluminum and rare earth industries to accelerate M&As.

  7. More Mergers,More Acquisitions

    2010-01-01

    China aims to maintain sound development of the national economy through M&As Anew round of corporate mergers and acquisitions (M&As) is on the way. On September 6, the State Council announced that it would require companies in the automobile, iron and steel, cement, machinery manufacturing, electro- lytic aluminum and rare earth industries to accelerate M&As.

  8. Acquisition streamlining: A cultural change

    Stewart, Jesse

    1992-01-01

    The topics are presented in viewgraph form and include the following: the defense systems management college, educational philosophy, the defense acquisition environment, streamlining initiatives, organizational streamlining types, defense law review, law review purpose, law review objectives, the Public Law Pilot Program, and cultural change.

  9. Language Acquisition and Language Revitalization

    O'Grady, William; Hattori, Ryoko

    2016-01-01

    Intergenerational transmission, the ultimate goal of language revitalization efforts, can only be achieved by (re)establishing the conditions under which an imperiled language can be acquired by the community's children. This paper presents a tutorial survey of several key points relating to language acquisition and maintenance in children,…

  10. Bilingualism and Third Language Acquisition.

    Garate, Jose Valencia; Iragui, Jasone Cenoz

    A study investigated the role of bilingualism (Basque/Spanish) and motivation in third (English) language acquisition in Spain's Basque country. Subjects were 321 secondary school students in two programs, one with instruction primarily in Spanish and one with instruction primarily in Basque. The following independent variables were analyzed in…

  11. Analog Input Data Acquisition Software

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  12. Data Acquisition and Flux Calculations

    Rebmann, C.; Kolle, O; Heinesch, B;

    2012-01-01

    In this chapter, the basic theory and the procedures used to obtain turbulent fluxes of energy, mass, and momentum with the eddy covariance technique will be detailed. This includes a description of data acquisition, pretreatment of high-frequency data and flux calculation....

  13. 企业国际并购知识吸收能力提升机制研究%Research on Exaltation Mechanism of Absorptive Capacity about Cross-border Mergers and Acquisitions

    梁力军; 孟凡臣

    2011-01-01

    Absorptive capacity is a research hotspot in recent years, and it is not only the core factor which could form and enhance technological capability of enterprises, but the key to obtain sustainable competitive advantage for modern enterprises. As complex organizations, cross-border mergers and acquisitions process is complex organizational behavior, coupled with cultural barriers, technical barriers, organizational barriers and knowledge distance, will affect directly or indirectly Absorptive capacity in cross-border M&As, thus affect the performance of knowledge transfer and M&As strategy. Under the cross-cultural, cross-organizational, cross-environmental background, it is critical to analyze objectively and systematically absorptive capacity status in cross-border M&As. Based on knowledge management, enterprises capacity, organizational learning, international M&As and complex theory, etc, the research proposed the absorptive capacity content, knowledge factors and effect factors in accordance with M&A characteristics. At the same time, the research employed system dynamics method to construct knowledge simulation model of absorptive capacity, further proposed future research directions and priorities.%知识吸收能力是近年来的研究热点,是形成和提升企业技术能力的核心要素,也是现代企业取得持续竞争优势的关键。由于国际并购是一种复杂性组织的复杂组织行为,加之文化障碍、技术障碍、组织障碍和知识距离的客观存在,将会对国际并购中的知识吸收能力产生直接或间接的影响,从而影响知识转移的效果和并购战略效果。在跨文化、跨组织、跨环境背景下,客观、系统地分析国际并购企业自身的知识吸收能力状况是至关重要的。研究将基于知识管理、企业能力、组织学习、国际并购和复杂性等学科理论,提出符合国际并购特点的知识吸收能力内涵、知识要素及影

  14. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    Liu, Tao; Li, Yingjun; Wang, Xiaodi

    2015-01-01

    Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I......, it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci...... in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence...

  15. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    Liu, Tao; Li, Yingjun; Wang, Xiaodi;

    2015-01-01

    , it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci......Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I...... in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence...

  16. Buffer gas acquisition and storage

    Parrish, Clyde F.; Lueck, Dale E.; Jennings, Paul A.

    2001-02-01

    The acquisition and storage of buffer gases (primarily argon and nitrogen) from the Mars atmosphere provides a valuable resource for blanketing and pressurizing fuel tanks and as a buffer gas for breathing air for manned missions. During the acquisition of carbon dioxide (CO2), whether by sorption bed or cryo-freezer, the accompanying buffer gases build up in the carbon dioxide acquisition system, reduce the flow of CO2 to the bed, and lower system efficiency. It is this build up of buffer gases that provide a convenient source, which must be removed, for efficient capture of CO2. Removal of this buffer gas barrier greatly improves the charging rate of the CO2 acquisition bed and, thereby, maintains the fuel production rates required for a successful mission. Consequently, the acquisition, purification, and storage of these buffer gases are important goals of ISRU plans. Purity of the buffer gases is a concern e.g., if the CO2 freezer operates at 140 K, the composition of the inert gas would be approximately 21 percent CO2, 50 percent nitrogen, and 29 percent argon. Although there are several approaches that could be used, this effort focused on a hollow-fiber membrane (HFM) separation method. This study measured the permeation rates of CO2, nitrogen (N2), and argon (Ar) through a multiple-membrane system and the individual membranes from room temperature to 193 K and 10 kPa to 300 kPa. Concentrations were measured with a gas chromatograph. The end result was data necessary to design a system that could separate CO2, N2, and Ar. .

  17. Buffer Gas Acquisition and Storage

    Parrish, Clyde F.; Lueck, Dale E.; Jennings, Paul A.; Callahan, Richard A.; Delgado, H. (Technical Monitor)

    2001-01-01

    The acquisition and storage of buffer gases (primarily argon and nitrogen) from the Mars atmosphere provides a valuable resource for blanketing and pressurizing fuel tanks and as a buffer gas for breathing air for manned missions. During the acquisition of carbon dioxide (CO2), whether by sorption bed or cryo-freezer, the accompanying buffer gases build up in the carbon dioxide acquisition system, reduce the flow of CO2 to the bed, and lower system efficiency. It is this build up of buffer gases that provide a convenient source, which must be removed, for efficient capture Of CO2 Removal of this buffer gas barrier greatly improves the charging rate of the CO2 acquisition bed and, thereby, maintains the fuel production rates required for a successful mission. Consequently, the acquisition, purification, and storage of these buffer gases are important goals of ISRU plans. Purity of the buffer gases is a concern e.g., if the CO, freezer operates at 140 K, the composition of the inert gas would be approximately 21 percent CO2, 50 percent nitrogen, and 29 percent argon. Although there are several approaches that could be used, this effort focused on a hollow-fiber membrane (HFM) separation method. This study measured the permeation rates of CO2, nitrogen (ND, and argon (Ar) through a multiple-membrane system and the individual membranes from room temperature to 193K and 10 kpa to 300 kPa. Concentrations were measured with a gas chromatograph that used a thermoconductivity (TCD) detector with helium (He) as the carrier gas. The general trend as the temperature was lowered was for the membranes to become more selective, In addition, the relative permeation rates between the three gases changed with temperature. The end result was to provide design parameters that could be used to separate CO2 from N2 and Ar.

  18. 48 CFR 307.104-70 - Acquisition strategy.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Acquisition strategy. 307... AND ACQUISITION PLANNING ACQUISITION PLANNING Acquisition Planning 307.104-70 Acquisition strategy... designated by the HHS CIO, DASFMP, the CAO, or the cognizant HCA) shall prepare an acquisition strategy...

  19. Nutrient profiling of foods: creating a nutrient-rich food index.

    Drewnowski, Adam; Fulgoni, Victor

    2008-01-01

    Nutrient profiling of foods, described as the science of ranking foods based on their nutrient content, is fast becoming the basis for regulating nutrition labels, health claims, and marketing and advertising to children. A number of nutrient profile models have now been developed by research scientists, regulatory agencies, and by the food industry. Whereas some of these models have focused on nutrients to limit, others have emphasized nutrients known to be beneficial to health, or some combination of both. Although nutrient profile models are often tailored to specific goals, the development process ought to follow the same science-driven rules. These include the selection of index nutrients and reference amounts, the development of an appropriate algorithm for calculating nutrient density, and the validation of the chosen nutrient profile model against healthy diets. It is extremely important that nutrient profiles be validated rather than merely compared to prevailing public opinion. Regulatory agencies should act only when they are satisfied that the scientific process has been followed, that the algorithms are transparent, and that the profile model has been validated with respect to objective measures of a healthy diet.

  20. Modeling the distinct phases of skill acquisition.

    Tenison, Caitlin; Anderson, John R

    2016-05-01

    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 calculation to retrieval). In the current study, we use hidden Markov modeling to identify transitions in the learning process. This method accounts for the gradual speedup in problem solving and also uncovers abrupt changes in reaction time, which reflect changes in the cognitive processes that participants are using to solve math problems. We find that as participants practice solving math problems they transition through 3 distinct learning states. Each learning state shows some speedup with practice, but the major speedups are produced by transitions between learning states. In examining and comparing the behavioral and neurological profiles of each of these states, we find parallels with the 3 phases of skill acquisition proposed by Fitts and Posner (1967): a cognitive, an associative, and an autonomous phase. (PsycINFO Database Record

  1. Fertilizer-dependent efficiency of Pseudomonads for improving growth, yield, and nutrient use efficiency of wheat (Triticum aestivum L.).

    Shaharoona, Baby; Naveed, Muhammad; Arshad, Muhammad; Zahir, Zahir A

    2008-05-01

    Acquisition of nutrients by plants is primarily dependent on root growth and bioavailability of nutrients in the rooting medium. Most of the beneficial bacteria enhance root growth, but their effectiveness could be influenced by the nutrient status around the roots. In this study, two 1-aminocyclopropane-1-carboxylate (ACC)-deaminase containing plant-growth-promoting rhizobacteria (PGPR), Pseudomonas fluorescens and P. fluorescens biotype F were tested for their effect on growth, yield, and nutrient use efficiency of wheat under simultaneously varying levels of all the three major nutrients N, P, and K (at 0%, 25%, 50%, 75%, and 100% of recommended doses). Results of pot and field trials revealed that the efficacy of these strains for improving growth and yield of wheat reduced with the increasing rates of NPK added to the soil. In most of the cases, significant negative linear correlations were recorded between percentage increases in growth and yield parameters of wheat caused by inoculation and increasing levels of applied NPK fertilizers. It is highly likely that under low fertilizer application, the ACC-deaminase activity of PGPR might have caused reduction in the synthesis of stress (nutrient)-induced inhibitory levels of ethylene in the roots through ACC hydrolysis into NH(3) and alpha-ketobutyrate. The results of this study imply that these Pseudomonads could be employed in combination with appropriate doses of fertilizers for better plant growth and savings of fertilizers.

  2. 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; Lemoine, Nathan P; Rosales, Stephanie; Fuchs, Corinne; Maynard, Jeffrey A; Thurber, Rebecca Vega

    2016-06-07

    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 pollution. These stressors increase turf and macroalgal cover, destabilizing microbiomes, elevating putative pathogen loads, increasing disease more than twofold and increasing mortality up to eightfold. Above-average temperatures exacerbate these effects, further disrupting microbiomes of unhealthy corals and concentrating 80% of mortality in the warmest seasons. Surprisingly, nutrients also increase bacterial opportunism and mortality in corals bitten by parrotfish, turning normal trophic interactions deadly for corals. Thus, overfishing and nutrient pollution impact reefs down to microbial scales, killing corals by sensitizing them to predation, above-average temperatures and bacterial opportunism.

  3. 48 CFR 434.004 - Acquisition strategy.

    2010-10-01

    ... information technology systems are included in the USDA Information Technology Capital Planning and Investment... manager will develop, in coordination with the Acquisition Executive or Major Information Technology... approval of the Acquisition Executive or Major Information Technology Systems Executive, a project...

  4. Kellwood Company Finalizes Acquisition of ADAM

    2010-01-01

    The Town and Country-based apparel company Kellwood Company announced its acquisition of ADAM according to Michael Kramer,Chief Executive Officer and President of Kellwood.This acquisition is the first in

  5. Nutrient enrichment increases mortality of mangroves.

    Catherine E Lovelock

    Full Text Available Nutrient enrichment of the coastal zone places intense pressure on marine communities. Previous studies have shown that growth of intertidal mangrove forests is accelerated with enhanced nutrient availability. However, nutrient enrichment favours growth of shoots relative to roots, thus enhancing growth rates but increasing vulnerability to environmental stresses that adversely affect plant water relations. Two such stresses are high salinity and low humidity, both of which require greater investment in roots to meet the demands for water by the shoots. Here we present data from a global network of sites that documents enhanced mortality of mangroves with experimental nutrient enrichment at sites where high sediment salinity was coincident with low rainfall and low humidity. Thus the benefits of increased mangrove growth in response to coastal eutrophication is offset by the costs of decreased resilience due to mortality during drought, with mortality increasing with soil water salinity along climatic gradients.

  6. Tree root systems and nutrient mobilization

    Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten;

    Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... of nutrient elements essential for forest growth and resilience. Research and techniques have signifi cantly advanced since Olof Tamm’s 1934 base mineral index for Swedish forest soils, and basic nutrient budget estimates for whole-tree harvesting systems of the 1970s. Recent research in areas that include...... sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations...

  7. Scaling laws in phytoplankton nutrient uptake affinity

    Lindemann, Christian; Fiksen, Øyvind; Andersen, Ken Haste

    2016-01-01

    Nutrient uptake affinity affects the competitive ability of microbial organisms at low nutrient concentrations. From the theory of diffusion limitation it follows that uptake affinity scales linearly with the cell radius. This is in conflict with some observations suggesting that uptake affinity...... scales to a quantity that is closer to the square of the radius, i.e. to cell surface area. We show that this apparent conflict can be resolved by nutrient uptake theory. Pure diffusion limitation assumes that the cell is a perfect sink which means that it is able to absorb all encountered nutrients...... to volume ratio. We show that there are two reasons for this. First, because the small cells need a higher transporter density in order to maximize their affinity, and second because the relative cost of a transporter is higher for a small than for a large cell. We suggest that this might explain why...

  8. Nutrient Enrichment Increases Mortality of Mangroves

    Lovelock, Catherine E.; Ball, Marilyn C.; Martin, Katherine C.; C. Feller, Ilka

    2009-01-01

    Nutrient enrichment of the coastal zone places intense pressure on marine communities. Previous studies have shown that growth of intertidal mangrove forests is accelerated with enhanced nutrient availability. However, nutrient enrichment favours growth of shoots relative to roots, thus enhancing growth rates but increasing vulnerability to environmental stresses that adversely affect plant water relations. Two such stresses are high salinity and low humidity, both of which require greater investment in roots to meet the demands for water by the shoots. Here we present data from a global network of sites that documents enhanced mortality of mangroves with experimental nutrient enrichment at sites where high sediment salinity was coincident with low rainfall and low humidity. Thus the benefits of increased mangrove growth in response to coastal eutrophication is offset by the costs of decreased resilience due to mortality during drought, with mortality increasing with soil water salinity along climatic gradients. PMID:19440554

  9. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  10. Food Sources of Important Nutrients (for Vegetarians)

    ... For Women For Seniors Food Sources of 5 Important Nutrients for Vegetarians Reviewed by Taylor Wolfram, MS, ... each meal increases iron absorption. Sources include: Fortified breakfast cereals Soybeans Some dark leafy greens including spinach ...

  11. Effect of two natural light regimes and nutrient addition on the forest herb Begonia decandra (Begoniaceae).

    Cordero, R A

    2000-01-01

    The effect of two natural light-growing conditions (understory versus light gaps) and the interaction with nutrient availability (through fertilization) were studied in the understory herb Begonia decandra, in the Luquillo Experimental Forest in Puerto Rico. Sixteen potted plants obtained from cuttings were randomly chosen and distributed in each of eighth forest environments (four light gaps and four understories), for a total of 128 plants. Fertilizer was applied to half of the plants in each site. After seven months in the two given microenvironments, increased light and fertilization resulted in greater growth and some changes in the biomass allocation patterns. All measured variables responded similarly to reported changes for tree seedlings and saplings from other tropical and subtropical regions. Total growth parameters (height, biomass and leaf area) were very sensitive to increases in the main resource (light). The addition of nutrients was less important in producing changes in the allocation variables (root to shoot ratio, leaf area ratio, and specific leaf mass) under conditions of high light availability. Changes due to nutrient levels were relatively greater on plants grown under under-story conditions. Also, small light differences among sites can cause significant changes in the variables related to total growth. Lastly, plant mortality in the nutrient treatments was found to be independent of mortality in two forest light environments. Some hypotheses about resource acquisition and plant growth are not supported by this data.

  12. Nutrient composition of important fish species in Bangladesh and potential contribution to recommended nutrient intakes

    Bogard, Jessica R.; Thilsted, Shakuntala H.; Marks, Geoffrey C.;

    2015-01-01

    Fish, in Bangladesh where malnutrition remains a significant development challenge, is an irreplaceable animal-source food in the diet of millions. However, existing data on the nutrient composition of fish do not reflect the large diversity available and have focused on only a few select nutrients....... The purpose of this study was to fill the gaps in existing data on the nutrient profiles of common fish in Bangladesh by analysing the proximate, vitamin, mineral and fatty acid composition of 55 fish, shrimp and prawn species from inland capture, aquaculture and marine capture fisheries. When comparing......, and all typically consumed whole with head and bones, could potentially contribute ≥25% of RNIs for three or more of these nutrients, simultaneously, from a standard portion. This illustrates the diversity in nutrient content of fish species and in particular the rich nutrient composition of small...

  13. Early-stage changes in natural (13)C and (15)N abundance and nutrient dynamics during different litter decomposition.

    Gautam, Mukesh Kumar; Lee, Kwang-Sik; Song, Byeong-Yeol; Lee, Dongho; Bong, Yeon-Sik

    2016-05-01

    Decomposition, nutrient, and isotopic (δ(13)C and δ(15)N) dynamics during 1 year were studied for leaf and twig litters of Pinus densiflora, Castanea crenata, Erigeron annuus, and Miscanthus sinensis growing on a highly weathered soil with constrained nutrient supply using litterbags in a cool temperate region of South Korea. Decay constant (k/year) ranged from 0.58 to 1.29/year, and mass loss ranged from 22.36 to 58.43 % among litter types. The results demonstrate that mass loss and nutrient dynamics of decomposing litter were influenced by the seasonality of mineralization and immobilization processes. In general, most nutrients exhibited alternate phases of rapid mineralization followed by gradual immobilization, except K, which was released throughout the field incubation. At the end of study, among all the nutrients only N and P showed net immobilization. Mobility of different nutrients from decomposing litter as the percentage of initial litter nutrient concentration was in the order of K > Mg > Ca > N ≈ P. The δ(13)C (0.32-6.70 ‰) and δ(15)N (0.74-3.90 ‰) values of residual litters showed nonlinear increase and decrease, respectively compared to initial isotopic values during decomposition. Litter of different functional types and chemical quality converged toward a conservative nutrient use strategy through mechanisms of slow decomposition and slow nutrient mobilization. Our results indicate that litter quality and season, are the most important regulators of litter decomposition in these forests. The results revealed significant relationships between litter decomposition rates and N, C:N ratio and P, and seasonality (temperature). These results and the convergence of different litters towards conservative nutrient use in these nutrient constrained ecosystems imply optimization of litter management because litter removal can have cascading effects on litter decomposition and nutrient availability in these systems.

  14. Nutrient dynamics and metabolism in Mediterranean streams affected by nutrient inputs from human activities

    2006-01-01

    A full understanding of nutrient cycling in lotic ecosystems is crucial given the increasing influence of human activities on the eutrophication of streams and rivers. However, existing knowledge about nutrient cycling in human-altered streams (i.e., receiving point and diffuse sources) is still limited. The general objective of this dissertation was to examine point source effects on stream functional attributes, such as nutrient retention, denitrification and metabolism rates. We also quant...

  15. Shoot Apex Demand Determines Assimilate and Nutrients Partitioning and Nutrient-uptake Rate in Tobacco Plants

    2007-01-01

    Our previous experiment revealed that apex-removed plants have larger root systems but a lower K+-uptake rates than intact tobacco plants.Since the apex is not only e center of growth and metabolism,but also an important place of auxin synthesis and export,the aims of this study were to distinguish whether the apex demand or auxin synthesized in the apex regulates assimilate and nutrients partitioning within plant,and to explain the reason for the lower K+-uptake rate of the apex-ramoved plant.In comparison with the control plant,covering the shoot apex with a black transparent plastic bag reduced net increases In dry matter and nutrients;however,the distribution of the dry matter and nutrients between shoot and roots and nutrient-uptake rates were not changed.Removal of the shoot apex shifted the dry mass and nutrients distributions to roots,and reduced the rate of nutrient uptake.Application of 1-naphthylacetic acid(NAA) could partly replace the role of the removed apex,stimulated assimilate and nutrient deposition into the treated tissue,and enhanced the reduced plasma membrane ATPase activity of roots to the control level.However,treatment of the apex-removed plants with NAA could not rescue the reduced nutrient uptake rate and the shifted assimilates and nutrients partitioning caused by excision of the apex.Higher nutrient uptake rate of the intact plants could not be explained by root growth parameters,such as total root surface area and number of root tips.The results from the present study indicate that strong apex demand determined assimilatas and nutrients partitioning and nutrient-uptake rate in tobacco(Nicotiana tabacum)plants.

  16. Acquisitions by EMNCs in Developed Markets

    Rabbiosi, Larissa; Elia, Stefano; Bertoni, Fabio

    2012-01-01

    in developed countries (south-north acquisitions). We test our hypotheses on a sample of 808 south-north acquisitions. The acquisitions were undertaken in Europe, Japan and North America (Canada and the US) between 1999 and 2008 by firms from the emerging economies of Brazil, Russia, India and China...

  17. 23 CFR 710.309 - Acquisition.

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Acquisition. 710.309 Section 710.309 Highways FEDERAL... ESTATE Project Development § 710.309 Acquisition. The process of acquiring real property includes... settlements, and condemnation. The State shall conduct acquisition and related relocation activities...

  18. 48 CFR 970.2301 - Sustainable acquisition.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Sustainable acquisition. 970.2301 Section 970.2301 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY..., Renewable Energy Technologies, Occupational Safety and Drug-Free Work Place 970.2301 Sustainable...

  19. Pidginization and Creolization as Language Acquisition.

    Andersen, Roger W., Ed.

    Pidginization and creolization are addressed from a language acquisition perspective. The 18 collected papers are organized around four areas of inquiry: (1) simplification in input to pidginization and second language acquisition, (2) simplification in interlanguage, (3) creolization and language acquisition, and (4) decreolization and language…

  20. Nutrient additions to mitigate for loss of Pacific salmon: consequences for stream biofilm and nutrient dynamics

    Marcarelli, Amy M.; Baxter, Colden V.; Wipfli, Mark S.

    2014-01-01

    Mitigation activities designed to supplement nutrient and organic matter inputs to streams experiencing decline or loss of Pacific salmon typically presuppose that an important pathway by which salmon nutrients are moved to fish (anadromous and/or resident) is via nutrient incorporation by biofilms and subsequent bottom-up stimulation of biofilm production, which is nutrient-limited in many ecosystems where salmon returns have declined. Our objective was to quantify the magnitude of nutrient incorporation and biofilm dynamics that underpin this indirect pathway in response to experimental additions of salmon carcasses and pelletized fish meal (a.k.a., salmon carcass analogs) to 500-m reaches of central Idaho streams over three years. Biofilm standing crops increased 2–8-fold and incorporated marine-derived nutrients (measured using 15N and 13C) in the month following treatment, but these responses did not persist year-to-year. Biofilms were nitrogen (N) limited before treatments, and remained N limited in analog, but not carcass-treated reaches. Despite these biofilm responses, in the month following treatment total N load was equal to 33–47% of the N added to the treated reaches, and N spiraling measurements suggested that as much as 20%, but more likely 2–3% of added N was taken up by microbes. Design of biologically and cost-effective strategies for nutrient addition will require understanding the rates at which stream microbes take up nutrients and the downstream distance traveled by exported nutrients.

  1. Photovoltaic module parameters acquisition model

    Cibira, Gabriel; Koščová, Marcela

    2014-09-01

    This paper presents basic procedures for photovoltaic (PV) module parameters acquisition using MATLAB and Simulink modelling. In first step, MATLAB and Simulink theoretical model are set to calculate I-V and P-V characteristics for PV module based on equivalent electrical circuit. Then, limited I-V data string is obtained from examined PV module using standard measurement equipment at standard irradiation and temperature conditions and stated into MATLAB data matrix as a reference model. Next, the theoretical model is optimized to keep-up with the reference model and to learn its basic parameters relations, over sparse data matrix. Finally, PV module parameters are deliverable for acquisition at different realistic irradiation, temperature conditions as well as series resistance. Besides of output power characteristics and efficiency calculation for PV module or system, proposed model validates computing statistical deviation compared to reference model.

  2. Music and Early Language Acquisition

    Anthony K. Brandt

    2012-09-01

    Full Text Available Language is typically viewed as fundamental to human intelligence. Music, while recognized as a human universal, is often treated as an ancillary ability—one dependent on or derivative of language. In contrast, we argue that it is more productive from a developmental perspective to describe spoken language as a special type of music. A review of existing studies presents a compelling case that musical hearing and ability is essential to language acquisition. In addition, the authors challenge the prevailing view that music cognition matures more slowly than language and is more difficult; instead, the authors present evidence that music learning matches the speed and effort of language acquisition. We conclude that music merits a central place in our understanding of human development.

  3. COLDEX New Data Acquisition Framework

    Grech, Christian

    2015-01-01

    COLDEX (COLD bore EXperiment) is an experiment of the TE-VSC group installed in the Super Proton Synchrotron (SPS) which mimics a LHC type cryogenic vacuum system. In the framework of the High Luminosity upgrade of the LHC (HL-LHC project), COLDEX has been recommissioned in 2014 in order to validate carbon coatings performances at cryogenic temperature with LHC type beams. To achieve this mission, a data acquisition system is needed to retrieve and store information from the different experiment’s systems (vacuum, cryogenics, controls, safety) and perform specific calculations. This work aimed to completely redesign, implement, test and operate a brand new data acquisition framework based on communication with the experiment’s PLCs for the devices potentially available over network. The communication protocol to the PLCs is based on data retrieval both from CERN middleware infrastructures (CMW, JAPC) and on a novel open source Simatic S7 data exchange package over TCP/IP (libnodave).

  4. A review of spelling acquisition

    Dich, Nadya; Cohn, Abigail C.

    2013-01-01

    literacy factors into modeling phonological knowledge. In this article, we show that the spelling acquisition data support and are best accounted for by models allowing for a hierarchy of representations, that learning to read and write has a profound effect on the phonological knowledge of an adult......This review article discusses how empirical data on the acquisition of spelling by children inform the question of the psycholinguistic validity of the phoneme, a concept central (at least implicitly) to most phonological theories. The paper reviews data on children's early spelling attempts...... as well as on the development of spelling proficiency. The evidence highlighted in the paper presents a number of challenges for many conceptions of the phoneme, which do not account for the complexity of the developmental data. A synthetic interpretation of the apparently contradictory evidence...

  5. DANSS Experiment Data Acquisition System

    Hons, Zdenek

    2016-01-01

    DANSS (Detector of the reactor AntiNeutrino based on Solid Scintillator) is a project aiming to measure a spectrum of reactor antineutrinos using inverse beta decay (IBD) in a plastic scintillator. The detector is located close to an industrial nuclear reactor core and is covered by passive and active shielding. It is expected to detect about 15000 IBD events per day. Light from the detector is sensed by PMT and SiPM. This paper describes the data acquisition system used for data readout of the 50 detector PMT channels and active shielding. Theoretical approach to the data acquisition is described and two possible solutions using QDCs and digitizers are discussed. Also described are the results of the DAQ performance during routine data taking operation of the detector.

  6. The ALICE data acquisition system

    Carena, F; Chapeland, S; Chibante Barroso, V; Costa, F; Dénes, E; Divià, R; Fuchs, U; Grigore, A; Kiss, T; Simonetti, G; Soós, C; Telesca, A; Vande Vyvre, P; Von Haller, B

    2014-01-01

    In this paper we describe the design, the construction, the commissioning and the operation of the Data Acquisition (DAQ) and Experiment Control Systems (ECS) of the ALICE experiment at the CERN Large Hadron Collider (LHC). The DAQ and the ECS are the systems used respectively for the acquisition of all physics data and for the overall control of the experiment. They are two computing systems made of hundreds of PCs and data storage units interconnected via two networks. The collection of experimental data from the detectors is performed by several hundreds of high-speed optical links. We describe in detail the design considerations for these systems handling the extreme data throughput resulting from central lead ions collisions at LHC energy. The implementation of the resulting requirements into hardware (custom optical links and commercial computing equipment), infrastructure (racks, cooling, power distribution, control room), and software led to many innovative solutions which are described together with ...

  7. 78 FR 80367 - Federal Acquisition Regulation; Federal Acquisition Circular 2005-72; Introduction

    2013-12-31

    ...This document summarizes the Federal Acquisition Regulation (FAR) rules agreed to by the Civilian Agency Acquisition Council and the Defense Acquisition Regulations Council (Councils) in this Federal Acquisition Circular (FAC) 2005-72. A companion document, the Small Entity Compliance Guide (SECG), follows this FAC. The FAC, including the SECG, is available via the Internet at......

  8. 76 FR 12357 - Federal Acquisition Regulation; Information Collection; Acquisition of Helium

    2011-03-07

    ...; Docket 2011-0079; Sequence 5] Federal Acquisition Regulation; Information Collection; Acquisition of... requirement concerning acquisition of helium. Public comments are particularly invited on: Whether this... cite OMB Control No. 9000-0113, Acquisition of Helium, in all correspondence. Dated: February 24,...

  9. 76 FR 11985 - Acquisition Regulation: Department of Energy Acquisition Regulation, Government Property

    2011-03-04

    ... Parts 908, 945, and 970 RIN 1991-AB86 Acquisition Regulation: Department of Energy Acquisition...: The Department of Energy (DOE) is proposing to amend the Department of Energy Acquisition Regulation (DEAR) to conform to the Federal Acquisition Regulation (FAR), remove out-of date government...

  10. Programmable fast data acquisition system

    Montebugnoli, S.; Bianchi, G.; Zoni, L.

    The goal of this work is to investigate the possibility to install on modern radiotelescopes a fast and programmable backend instead of several backends, each dedicated to a single acquisition task. Such an approach could lower the costs and make available a more compact and flexible back end. Exploiting the state-of-the-art of the FPGAs (Field Programmable Gate Arrays) and innovative architectures, a programmable system might be conceived.

  11. Data Acquisition and Mass Storage

    Vande Vyvre, P.

    2004-08-01

    The experiments performed at supercolliders will constitute a new challenge in several disciplines of High Energy Physics and Information Technology. This will definitely be the case for data acquisition and mass storage. The microelectronics, communication, and computing industries are maintaining an exponential increase of the performance of their products. The market of commodity products remains the largest and the most competitive market of technology products. This constitutes a strong incentive to use these commodity products extensively as components to build the data acquisition and computing infrastructures of the future generation of experiments. The present generation of experiments in Europe and in the US already constitutes an important step in this direction. The experience acquired in the design and the construction of the present experiments has to be complemented by a large R&D effort executed with good awareness of industry developments. The future experiments will also be expected to follow major trends of our present world: deliver physics results faster and become more and more visible and accessible. The present evolution of the technologies and the burgeoning of GRID projects indicate that these trends will be made possible. This paper includes a brief overview of the technologies currently used for the different tasks of the experimental data chain: data acquisition, selection, storage, processing, and analysis. The major trends of the computing and networking technologies are then indicated with particular attention paid to their influence on the future experiments. Finally, the vision of future data acquisition and processing systems and their promise for future supercolliders is presented.

  12. Data acquisition for sensor systems

    Taylor, H Rosemary

    1997-01-01

    'Data acquisition' is concerned with taking one or more analogue signals and converting them to digital form with sufficient accu­ racy and speed to be ready for processing by a computer. The increasing use of computers makes this an expanding field, and it is important that the conversion process is done correctly because information lost at this stage can never be regained, no matter how good the computation. The old saying - garbage in, garbage out - is very relevant to data acquisition, and so every part of the book contains a discussion of errors: where do they come from, how large are they, and what can be done to reduce them? The book aims to treat the data acquisition process in depth with less detailed chapters on the fundamental principles of measure­ ment, sensors and signal conditioning. There is also a chapter on software packages, which are becoming increasingly popular. This is such a rapidly changing topic that any review of available pro­ grams is bound to be out of date before the book re...

  13. Confidence-Based Feature Acquisition

    Wagstaff, Kiri L.; desJardins, Marie; MacGlashan, James

    2010-01-01

    Confidence-based Feature Acquisition (CFA) is a novel, supervised learning method for acquiring missing feature values when there is missing data at both training (learning) and test (deployment) time. To train a machine learning classifier, data is encoded with a series of input features describing each item. In some applications, the training data may have missing values for some of the features, which can be acquired at a given cost. A relevant JPL example is that of the Mars rover exploration in which the features are obtained from a variety of different instruments, with different power consumption and integration time costs. The challenge is to decide which features will lead to increased classification performance and are therefore worth acquiring (paying the cost). To solve this problem, CFA, which is made up of two algorithms (CFA-train and CFA-predict), has been designed to greedily minimize total acquisition cost (during training and testing) while aiming for a specific accuracy level (specified as a confidence threshold). With this method, it is assumed that there is a nonempty subset of features that are free; that is, every instance in the data set includes these features initially for zero cost. It is also assumed that the feature acquisition (FA) cost associated with each feature is known in advance, and that the FA cost for a given feature is the same for all instances. Finally, CFA requires that the base-level classifiers produce not only a classification, but also a confidence (or posterior probability).

  14. Foreign acquisition, plant survival, and employment growth

    Bandick, Roger; Görg, Holger

    2010-01-01

    endogeneity of acquisition using IV and propensity score matching approaches suggest that acquisition by foreign owners increases the lifetime of the acquired plants only if the plant was an exporter. The effect is robust to controlling for domestic acquisitions and differs between horizontal and vertical...... acquisitions. We find robust positive employment growth effects only for exporters and only if the takeover is vertical.......This paper analyzes the effect of foreign acquisition on survival and employment growth of targets using data on Swedish manufacturing plants.We separate targeted plants into those within Swedish MNEs, Swedish exporting non-MNEs, and purely domestic firms. The results, controlling for possible...

  15. Variation in nutrients formulated and nutrients supplied on 5 California dairies.

    Rossow, H A; Aly, S S

    2013-01-01

    Computer models used in ration formulation assume that nutrients supplied by a ration formulation are the same as the nutrients presented in front of the cow in the final ration. Deviations in nutrients due to feed management effects such as dry matter changes (i.e., rain), loading, mixing, and delivery errors are assumed to not affect delivery of nutrients to the cow and her resulting milk production. To estimate how feed management affects nutrients supplied to the cow and milk production, and determine if nutrients can serve as indexes of feed management practices, weekly total mixed ration samples were collected and analyzed for 4 pens (close-up cows, fresh cows, high-milk-producing, and low-milk-producing cows, if available) for 7 to 12 wk on 5 commercial California dairies. Differences among nutrient analyses from these samples and nutrients from the formulated rations were analyzed by PROC MIXED of SAS (SAS Institute Inc., Cary, NC). Milk fat and milk protein percentages did not vary as much [coefficient of variation (CV) = 18 to 33%] as milk yield (kg; CV = 16 to 47 %) across all dairies and pens. Variability in nutrients delivered were highest for macronutrient fat (CV = 22%), lignin (CV = 15%), and ash (CV = 11%) percentages and micronutrients Fe (mg/kg; CV = 48%), Na (%; CV = 42%), and Zn (mg/kg; CV = 38%) for the milking pens across all dairies. Partitioning of the variability in random effects of nutrients delivered and intraclass correlation coefficients showed that variability in lignin percentage of TMR had the highest correlation with variability in milk yield and milk fat percentage, followed by fat and crude protein percentages. But, variability in ash, fat, and lignin percentages of total mixed ration had the highest correlation with variability in milk protein percentage. Therefore, lignin, fat, and ash may be the best indices of feed management to include effects of variability in nutrients on variability in milk yield, milk fat, and milk

  16. Variation in wood nutrients along a tropical soil fertility gradient.

    Heineman, Katherine D; Turner, Benjamin L; Dalling, James W

    2016-07-01

    Wood contains the majority of the nutrients in tropical trees, yet controls over wood nutrient concentrations and their function are poorly understood. We measured wood nutrient concentrations in 106 tree species in 10 forest plots spanning a regional fertility gradient in Panama. For a subset of species, we quantified foliar nutrients and wood density to test whether wood nutrients scale with foliar nutrients at the species level, or wood nutrient storage increases with wood density as predicted by the wood economics spectrum. Wood nutrient concentrations varied enormously among species from fourfold in nitrogen (N) to > 30-fold in calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P). Community-weighted mean wood nutrient concentrations correlated positively with soil Ca, K, Mg and P concentrations. Wood nutrients scaled positively with leaf nutrients, supporting the hypothesis that nutrient allocation is conserved across plant organs. Wood P was most sensitive to variation in soil nutrient availability, and significant radial declines in wood P indicated that tropical trees retranslocate P as sapwood transitions to heartwood. Wood P decreased with increasing wood density, suggesting that low wood P and dense wood are traits associated with tree species persistence on low fertility soils. Substantial variation among species and communities in wood nutrient concentrations suggests that allocation of nutrients to wood, especially P, influences species distributions and nutrient dynamics in tropical forests.

  17. Acquisition system for the CLIC Module

    Vilalte, Sebastien

    2011-01-01

    The status of R&D activities for CLIC module acquisition are discussed [1]. LAPP is involved in the design of the local CLIC module acquisition crate, described in the document Study of the CLIC Module Front-End Acquisition and Evaluation Electronics [2]. This acquisition system is a project based on a local crate, assigned to the CLIC module, including several mother boards. These motherboards are foreseen to hold mezzanines dedicated to the different subsystems. This system has to work in radiation environment. LAPP is involved in the development of Drive Beam stripline position monitors read-out, described in the document Drive Beam Stripline BPM Electronics and Acquisition [3]. LAPP also develops a generic acquisition mezzanine that allows to perform all-around acquisition and components tests for drive beam stripline BPM read-out.

  18. Nonredundant Roles of Iron Acquisition Systems in Vibrio cholerae.

    Peng, Eric D; Wyckoff, Elizabeth E; Mey, Alexandra R; Fisher, Carolyn R; Payne, Shelley M

    2015-12-07

    Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, thrives in both marine environments and the human host. To do so, it must encode the tools necessary to acquire essential nutrients, including iron, under these vastly different conditions. A number of V. cholerae iron acquisition systems have been identified; however, the precise role of each system is not fully understood. To test the roles of individual systems, we generated a series of mutants in which only one of the four systems that support iron acquisition on unsupplemented LB agar, Feo, Fbp, Vct, and Vib, remains functional. Analysis of these mutants under different growth conditions showed that these systems are not redundant. The strain carrying only the ferrous iron transporter Feo grew well at acidic, but not alkaline, pH, whereas the ferric iron transporter Fbp promoted better growth at alkaline than at acidic pH. A strain defective in all four systems (null mutant) had a severe growth defect under aerobic conditions but accumulated iron and grew as well as the wild type in the absence of oxygen, suggesting the presence of an additional, unidentified iron transporter in V. cholerae. In support of this, the null mutant was only moderately attenuated in an infant mouse model of infection. While the null mutant used heme as an iron source in vitro, we demonstrate that heme is not available to V. cholerae in the infant mouse intestine.

  19. Nutrient omission in Bt cotton affects soil organic carbon and nutrients status

    Aladakatti, Y. R.; Biradar, D. P.; Satyanarayana, T.; Majumdar, K.; Shivamurthy, D.

    2012-04-01

    Studies carried out at the University of Agricultural Sciences, Dharwad, India, in medium black soils assessed the effect of nutrient omission in Bt cotton and its effect on the soil organic carbon (SOC) and available nutrients at the end of second consecutive year of nutrient omission. The study also assessed the extent of contribution of the macro and micronutrients towards seed cotton yield. The experiment consisting 11 treatments omitting a nutrient in each treatment including an absolute control without any nutrients was conducted in a Randomised Block Design with three replications. Cotton crop sufficiently fertilized with macro and micro nutrients (165 : 75 : 120 NPK kg ha-1 and 20 kg each of CaSO4, and MgSO4, 10 kg of S, 20 kg each of ZnSO4, FeSO4 and 0.1 per cent Boron twice as foliar spray) was taken as a standard check to assess the contribution of each nutrient in various nutrient omission treatments. Soils of each treatment were analysed initially and after each crop of cotton for SOC and available nutrient status. Results indicated that the SOC decreased after each crop of cotton in absolute control where no nutrients were applied (0.50 % to 0.38 %) and also in the N omission treatment (0.50 % to 0.35 %). But there was no significant impact of omission of P, K and other nutrients on soil organic carbon. Soil available N, P and K in the soil were reduced as compared to the initial soil status after first and second crop of cotton in the respective treatment where these nutrients were omitted. The soil available N, P and K were reduced to the extent of 61 kg ha-1, 7.1 kg ha-1 and 161.9 kg ha-1 in the respective nutrient omission treatment at end of second crop of cotton as compared to the initial status of these nutrients in the soil. This might be due to the mining of these nutrients from the soil nutrient pool with out addition of these nutrients extraneously. The nutrient status of N, P and K remained almost similar in omission of other nutrients

  20. Nutrient Requirements of Domestic Animals, Number 10: Nutrient Requirements of Laboratory Animals. Third Revised Edition, 1978.

    National Academy of Sciences - National Research Council, Washington, DC. Board on Agricultural and Renewable Resources.

    This report deals with the nutrient requirements of seven species of animals used extensively for biomedical research in the United States. Following an introductory chapter of general information on nutrition, chapters are presented on the nutrient requirements of the laboratory rat, mouse, gerbil, guinea pig, hamster, vole, and fishes. Each…

  1. Leaf nutrient resorption, leaf lifespan and the retention of nutrients in seagrass systems

    Hemminga, M.A.; Marbà, N.; Stapel, J.

    1999-01-01

    Efficient nutrient resorption from senescing leaves, and extended leaf life spans are important strategies in order to conserve nutrients for plants in general. Despite the fact that seagrasses often grow in oligotrophic waters, these conservation strategies are not strongly developed in seagrasses.

  2. Comparative mapping of rice root traits in seedlings grown in nutrient or non-nutrient solution

    XU Jichen; LI Xiaobo; ZHU Lihuang

    2004-01-01

    The component and amount of nutrient in the growth medium are the major factors affecting root growth.For the systematic dissection of root gene expression,evaluation of nutrient and non-nutrient solutions was conducted for their effect on root traits and quantitative trait loci(QTL)mapping.Three rice root parameters,maximum root length(MRL),root dry weight(RDW),and root/ shoot ratio of dry weight(RSR),were characterized within a double haploid(DH)population from a cross of ZYQ8(indica)and JX17(japonica).The value of the three root traits in two parents all decreased under the nutrient condition compared to those under the nonnutrient condition,of which RSR decreased up to 2.6-fold on average.In the DH population,more than 70 % lines in MRL,94 % lines in RDW,and all the lines in RSR were scored lower.In total,eight QTLs were identified in nutrient system(5 from JX17 alleles and 3 from ZYQ8 alleles)while five QTLs were detected in non-nutrient system(4 from JX17 alleles and 1 from ZYQ8 alleles).Of them,one QTL for RSR was shared by both culturing systems,seven QTLs were specific in nutrient system and the other four QTLs were specific in non-nutrient system.All 13 QTLs were distributed over 7 rice chromosomes-2,3,4,5,6,9 and 10,respectively.

  3. Fast Detection of Nutrient Limitation in Macroalgae and Seagrass with Nutrient-Induced Fluorescence

    den Haan, J.; Huisman, J.; Dekker, F.; ten Brinke, J.L.; Ford, A.K.; van Ooijen, J.; van Duyl, F.C.; Vermeij, M.J.A.; Visser, P.M.

    2013-01-01

    Background: Rapid determination of which nutrients limit the primary production of macroalgae and seagrasses is vital for understanding the impacts of eutrophication on marine and freshwater ecosystems. However, current methods to assess nutrient limitation are often cumbersome and time consuming. F

  4. Adaptation of carbon allocation under light and nutrient reduction

    Wegener, Frederik; Werner, Christiane

    2015-04-01

    The allocation of recently assimilated carbon (C) by plants depends on developmental stage and on environmental factors, but the underlying mechanisms are still a matter of debate. Whereas shifts in the allocation of photosynthates induced by reduced water availability, enhanced temperature and CO2 concentration were recently investigated in various studies, less is known about the response to light and nutrient reduction. We induced different allocation patterns in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analysed allocation parameters as well as morphological and physiological traits for 15 months. Finally, we conducted a 13CO2 pulse-labelling and followed the fate of recently assimilated carbon to eight different classes of plant tissues and respiration for 13 days. The results revealed a high intraspecific variability in C distribution to tissues and in respiration. Allocation changes even varied within leaf and stem tissue classes (e.g. more C in main stems, less in lateral stems). These results show that the common separation of plant tissues in only three classes, i.e. root, shoot and leaf tissues, can result in missing information about allocation changes. The nutrient reduction enhanced the transport of recently assimilated C from leaves to roots in terms of quantity (c. 200%) and velocity compared to control plants. Interestingly, a 57% light reduction enhanced photosynthetic capacity and caused no change in final biomass after 15 months. Therefore, our results support the recently discussed sink regulation of photosynthesis. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C loss from storage and structural C pools and therefore enhance the fraction of recent assimilates used for respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a control mechanism for C

  5. Facilitated Bioavailability of PAHs to Native Soil Bacteria Promoted by Nutrient Addition

    Pignatello, J. J.; Li, J.

    2006-12-01

    Facilitated bioavailability refers to the ability of an organism to have access to pools of non-labile chemical. Mechanisms proposed for this ability include release of biosurfactants, direct mining of adsorbed chemical, alteration of interfacial chemistry, and passive effects of attached biofilms on molecular diffusion. We investigated the biodegradation by indigenous organisms of a set of 16 standard polycyclic aromatic hydrocarbons (PAHs) in coal tar contaminated soil from a manufactured gas plant site in Connecticut in well- mixed aerobic reactors containing various additives over a 93-106 day period. Parallel desorption experiments were conducted in the presence of a biocide and an excess of Tenax-TA adsorbent beads to simulate desorption to infinite dilution (i.e., maximal concentration gradient for diffusion). Both biotransformation and desorption decreased with PAH ring size, as expected. Biodegradation by native organisms was strongly accelerated by addition of inorganic nutrients (N, P, K, and trace metals). In the absence of added nutrients, the biodegradation resistant fraction correlated well with the desorption resistant fraction. However, in the presence of added nutrients, the extent of biodegradation was greater than the extent of desorption except for the largest compounds, which neither degraded nor desorbed. The ability of nutrients to accelerate degradation of bioavailable PAHs by native cells indicates that the persistence of PAHs for many decades at this site is likely due to nutrient-limited natural attenuation. The surprising result of this study is that application of nutrients promotes `facilitated bioavailability' of PAHs in this soil to indigenous microorganisms.

  6. Nutrient solution cooling and its effect on temperature of leaf lettuce in hydroponic system.

    Nam, S W; Kim, M K; Son, J E

    1996-12-01

    The heat transfer characteristics of a hydroponic system were experimentally verified after theoretical establishment and the effect of nutrient solution cooling on the plant temperature was investigated. About 96 percent of the total heat flow transferred from culture bed to nutrient solution was the conductive heat through planting board and partitioning materials. The average and maximum temperatures of the leaf lettuce decreased 0.6 and 1.5 degrees C., respectively, with cooling of nutrient solution by 6 degrees C. A numerical model for prediction of cooling load of nutrient solution in a hydroponic greenhouse was developed, and the results from the simulation model showed a good agreement with those from experiments. A mechanical cooling system using the counter flow type with double pipes was developed for cooling the nutrient solution. Also the heat transfer characteristics of the system were analyzed experimentally and theoretically, and compared with the other existing cooling systems of nutrient solution. The cooling capacities of three different systems, which used polyethylene tube in solution tank, stainless tube in solution tank, and the counter flow type with double pipes, were comparatively evaluated.

  7. Effects of Nutrient Limitation on Pigments in Thalassiosira weissflogii and Prorocentrum donghaiense

    Jian-Jun Hou; Bang-Qin Huang; Zhen-Rui Cao; Ji-Xin Chen; Hua-Sheng Hong

    2007-01-01

    The response of Prorocentrum donghaiense and Thalassiosira weissflogii pigments under nitrate (N) and phosphate (P) limitation were studied using HPLC and in vlvo fluorescence protocols in batch cultures. For P. donghalense,the pigment ratio was kept stable under different nutrient conditions from the results of HPLC. For T. weissflogii,there was a lower ratio of chlorophyllide to Chi a during the exponential phase, but the reverse during the stationary phase. Different members of the phytoplankton had different pigments response mechanisms under nutrient limitation. From the results of in vivo fluorescence, the ratio of peridinin to Chl a for P. donghaiense increased in nutrient-free culture, while it was kept stable for nutrient-limited cultures during the exponential phase. For T.weissflogii, the ratio of fucoxanthin to Chl a for each culture increased during the exponential phase, but the ratio under N limitation was apparently lower than that for P limitation during the stationary phase. The results indicate that both pigment ratios from HPLC and In vivo fluorescence of T. weissflogii were changed greatly under different nutrient conditions, which suggests that both ratios could be used as indicators of algal physiological status in different nutrient conditions.

  8. Preliminary study on assessment of nutrient transport in the Taihu Basin based on SWAT modeling

    LAI; Geying; YU; Ge; GUI; Feng

    2006-01-01

    With the Taihu Basin as a study area, using the spatially distributed and mechanism-based SWAT model, preliminary simulations of nutrient transport in the Taihu Basin during the period of 1995~2002 has been carried out. The topography, soil, meteorology and land use with industrial point pollution discharge, the loss of agricultural fertilizers, urban sewerage, and livestock drainages were all considered in the boundary conditions of the simulations. The model was calibrated and validated against water quality monitoring data from 2001 to 2002. The results show that the annual total productions of nitrogen (TN) and phosphorus (TP) into Lake Taihu are 40000t and 2000t respectively. Nutrient from the Huxi Region is a major resource for Lake Taihu. The non-point source (surface source) pollution is the main form of catchment sources of nutrients into Lake Taihu,occupied TN 53% and TP 56% respectively. TN and TP nutrients from industrial point pollution discharge are 30% and 16%, and sewerage in both forms of point source and non-point source are TN 31% and TP 47%. Both the loss of agricultural fertilizers and livestock drainages from the catchment should be paid more attention as an important nutrient source. The results also show that SWAT is an effective model for the simulation of temporally and spatially nutrient changes and for the assessment of the trends in a catchment scale.

  9. Reproductive Hormone and Transcriptomic Responses of Pituitary Tissue in Anestrus Gilts Induced by Nutrient Restriction.

    Xu, Shengyu; Wang, Dingyue; Zhou, Dongsheng; Lin, Yan; Che, Lianqiang; Fang, Zhengfeng; Wu, De

    2015-01-01

    The onset of estrus is a critical sign of female sexual maturity. The pituitary plays a vital role in this process by the secretion of reproductive hormones. To investigate the effects of nutrient restriction on reproductive function and the underlying mechanisms involved, deep RNA sequencing of pituitary gland tissue was carried out to determine the differentially expressed genes (DEGs) between gilts in normal estrus, and gilts in which anestrus was induced by nutrient restriction. Gilts which had gone through two estrus cycles were fed a normal (CON, 2.86kg/d, n = 10) or nutrient restricted (NR, 1kg/d, n = 10) diet. The NR gilts experienced another three estrus cycles, but did not express estrus symptoms at the anticipated 6th and 7th cycles. Body weight gain in NR gilts was significantly decreased by nutrient restriction. Gilts were considered as anestrus when blood progesterone concentrations lower than 1.0 ng/mL from three consecutive blood samples were recorded. Circulating concentrations of progesterone (interaction", "GnRH signaling pathway" and "immune response system". Our findings provide a new perspective for understanding the nutrient restriction-induced reproductive impairment at the pituitary transcriptional level, and how this is linked to hormone secretion. Moreover, the transcriptomic changes in anestrus gilts associated with nutrient restriction could be a resource for targeted studies of genes and pathways potentially involved in the regulation of reproductive function and animal health.

  10. Nutrient Limitation in Central Red Sea Mangroves

    Almahasheer, Hanan

    2016-12-24

    As coastal plants that can survive in salt water, mangroves play an essential role in large marine ecosystems (LMEs). The Red Sea, where the growth of mangroves is stunted, is one of the least studied LMEs in the world. Mangroves along the Central Red Sea have characteristic heights of ~2 m, suggesting nutrient limitation. We assessed the nutrient status of mangrove stands in the Central Red Sea and conducted a fertilization experiment (N, P and Fe and various combinations thereof) on 4-week-old seedlings of Avicennia marina to identify limiting nutrients and stoichiometric effects. We measured height, number of leaves, number of nodes and root development at different time periods as well as the leaf content of C, N, P, Fe, and Chl a in the experimental seedlings. Height, number of nodes and number of leaves differed significantly among treatments. Iron treatment resulted in significantly taller plants compared with other nutrients, demonstrating that iron is the primary limiting nutrient in the tested mangrove population and confirming Liebig\\'s law of the minimum: iron addition alone yielded results comparable to those using complete fertilizer. This result is consistent with the biogenic nature of the sediments in the Red Sea, which are dominated by carbonates, and the lack of riverine sources of iron.

  11. Nutrients affecting brain composition and behavior

    Wurtman, R. J.

    1987-01-01

    This review examines the changes in brain composition and in various brain functions, including behavior, that can follow the ingestion of particular foods or nutrients. It details those that are best understood: the increases in serotonin, catecholamine, or acetylcholine synthesis that can occur subsequent to food-induced increases in brain levels of tryptophan, tyrosine, or choline; it also discusses the various processes that must intervene between the mouth and the synapse, so to speak, in order for a nutrient to affect neurotransmission, and it speculates as to additional brain chemicals that may ultimately be found to be affected by changes in the availability of their nutrient precursors. Because the brain chemicals best known to be nutrient dependent overlap with those thought to underlie the actions of most of the drugs used to treat psychiatric diseases, knowledge of this dependence may help the psychiatrist to understand some of the pathologic processes occurring in his/her patients, particularly those with appetitive symptoms. At the very least, such knowledge should provide the psychiatrist with objective criteria for judging when to take seriously assertions that particular foods or nutrients do indeed affect behavior (e.g., in hyperactive children). If the food can be shown to alter neurotransmitter release, it may be behaviorally-active; however, if it lacks a discernible neurochemical effect, the likelihood that it really alters behavior is small.

  12. Fishing down nutrients on coral reefs

    Allgeier, Jacob E.; Valdivia, Abel; Cox, Courtney; Layman, Craig A.

    2016-08-01

    Fishing is widely considered a leading cause of biodiversity loss in marine environments, but the potential effect on ecosystem processes, such as nutrient fluxes, is less explored. Here, we test how fishing on Caribbean coral reefs influences biodiversity and ecosystem functions provided by the fish community, that is, fish-mediated nutrient capacity. Specifically, we modelled five processes of nutrient storage (in biomass) and supply (via excretion) of nutrients, as well as a measure of their multifunctionality, onto 143 species of coral reef fishes across 110 coral reef fish communities. These communities span a gradient from extreme fishing pressure to protected areas with little to no fishing. We find that in fished sites fish-mediated nutrient capacity is reduced almost 50%, despite no substantial changes in the number of species. Instead, changes in community size and trophic structure were the primary cause of shifts in ecosystem function. These findings suggest that a broader perspective that incorporates predictable impacts of fishing pressure on ecosystem function is imperative for effective coral reef conservation and management.

  13. ASSESSING THE IMPACTS OF SALINITY AND NUTRIENT ...

    Healthy seagrass beds were once found throughout the shallow areas of Narragansett Bay, R.I. but have disappeared due to infilling, pollution and disease. In Greenwich Bay, a highly developed embayment within Narragansett Bay, Ruppia maritima has colonized an area on the northern shore once dominated by Zostera marina. This area is sandy, which may allow groundwater seepage. Ruppia is extremely salinity tolerant, and may also be more nutrient tolerant than Zostera. A six week microcosm experiment at two salinity (20 and 30 ppt) and 4 nutrient (0, 5, 10, and 30 µM inorganic N) levels to test their relative tolerance was conducted in 2014. Treatments were renewed daily to simulate tidal flushing and the exposure water was dosed with 15N for the first week of the experiment. At the end of the experiment, the plants were weighed and measured, and dried for later isotopic analysis. In the first experiment, Ruppia had significant structural responses to both nutrients and salinity; there was a slight decline in root weight and a decrease in the total number of shoots with increasing nutrients. Average Ruppia blade length decreased with increasing nutrients and this decrease was more evident at 30 ppt. In contrast, Zostera had no significant structural differences. For both species, there were no differences in shoot or root/rhizome weights in any treatment, nor were there differences in isotopic results due to salinity. However, δ15N in the tissue increase

  14. The potentials of multi-nutrient soil extraction with 0.01 M CaCl2 in nutrient management

    Erp, van P.J.

    2002-01-01

     Key words: 0.01 M CaCl 2 , soil testing, nutrient management, decision-making, multi-nutrientAim of this thesis is to improve the understanding of nutrient dynamics in soil and thereby to improve decision-making in nutrient management. There is a need for a more mechanistic

  15. Mussel farming as a nutrient reduction measure in the Baltic Sea: consideration of nutrient biogeochemical cycles.

    Stadmark, J; Conley, D J

    2011-07-01

    Nutrient loads from the land to the sea must be reduced to combat coastal eutrophication. It has been suggested that further mitigation efforts are needed in the brackish Baltic Sea to decrease nutrients, especially in eutrophic coastal areas. Mussel farming is a potential measure to remove nutrients directly from the sea. Mussels consume phytoplankton containing nitrogen (N) and phosphorus (P); when the mussels are harvested these nutrients are removed from the aquatic system. However, sedimentation of organic material in faeces and pseudo-faeces below a mussel farm consumes oxygen and can lead to hypoxic or even anoxic sediments causing an increased sediment release of ammonium and phosphate. Moreover, N losses from denitrification can be reduced due to low oxygen and reduced numbers of bioturbating organisms. To reveal if mussel farming is a cost-effective mitigation measure in the Baltic Sea the potential for enhanced sediment nutrient release must be assessed.

  16. Effects of nutrient addition on leaf chemistry, morphology, and photosynthetic capacity of three bog shrubs.

    Bubier, Jill L; Smith, Rose; Juutinen, Sari; Moore, Tim R; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash

    2011-10-01

    Plants in nutrient-poor environments typically have low foliar nitrogen (N) concentrations, long-lived tissues with leaf traits designed to use nutrients efficiently, and low rates of photosynthesis. We postulated that increasing N availability due to atmospheric deposition would increase photosynthetic capacity, foliar N, and specific leaf area (SLA) of bog shrubs. We measured photosynthesis, foliar chemistry and leaf morphology in three ericaceous shrubs (Vaccinium myrtilloides, Ledum groenlandicum and Chamaedaphne calyculata) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada, with a background deposition of 0.8 g N m(-2) a(-1). While biomass and chlorophyll concentrations increased in the highest nutrient treatment for C. calyculata, we found no change in the rates of light-saturated photosynthesis (A(max)), carboxylation (V(cmax)), or SLA with nutrient (N with and without PK) addition, with the exception of a weak positive correlation between foliar N and A(max) for C. calyculata, and higher V(cmax) in L. groenlandicum with low nutrient addition. We found negative correlations between photosynthetic N use efficiency (PNUE) and foliar N, accompanied by a species-specific increase in one or more amino acids, which may be a sign of excess N availability and/or a mechanism to reduce ammonium (NH(4)) toxicity. We also observed a decrease in foliar soluble Ca and Mg concentrations, essential minerals for plant growth, but no change in polyamines, indicators of physiological stress under conditions of high N accumulation. These results suggest that plants adapted to low-nutrient environments do not shift their resource allocation to photosynthetic processes, even after reaching N sufficiency, but instead store the excess N in organic compounds for future use. In the long term, bog species may not be able to take advantage of elevated nutrients, resulting in them being replaced by species that are better adapted to a higher nutrient environment.

  17. Nutrient exchange and release experiment and its simulation study in lake water-sediment interface

    XUE Lian-qing; HAO Zhen-chun

    2006-01-01

    The sediment distributed and insolated under lake was collected for experiments. The nutrient layer distribution conditions of sampled sediment and its physical and chemical characteristics were analyzed to simulate and assess the influence degree to lake water quality. Based on the dynamic water exchanging experiments the nutrient release process in sediment and influence mechanism to substance exchanging on water-sediment interface was studied, and the correlation between the changing content of total phosphors and total nitrogen in sediment and covered water were analyzed for setting up a simulation model. At the same time the influence degree is explained in detail. The experimental results indicated that even if clean water without nutrient contents was used for water exchangement so as to decrease pollution or prevent eutrophication, however owing to the vertical nutrient distribution in lake sediment, it will lead to the increasing release amount greatly especially when the organic nutrient contained in sediment turns into inorganic status because of isolation. Besides the release process of total phosphate (TP) and total nitrogen (TN) were modeled and each nutrient's exchanging equation at interface caused by covered water nutrient concentration changing was set up. According to the simulating prediction, TP and TN content of cover water will also sustain a steady higher level in a long period. The nutrient release amount of sediment is not only affected by the covered water concentration but also connects with accumulative time. The experiments provide the fundamental theoretical and practical basis for taking ecological restoration project. And research is helpful to prevent or restore lake eutrophication.

  18. SPATIAL DISTRIBUTION OF NUTRIENTS OF SHALLOW LAKE IN THE ZHALONG WETLAND

    WANG Lei; ZHANG Guang-Xin

    2006-01-01

    The Zhalong wetland, a Ramsar listed wetland in China, which is located in the lower reaches of the Wuyu'er River, perennially takes in lots of nutrient input of N and P from around the catchment.Nutrient substances were especially accumulated in the shallow lakes owning to the low-lying topography.The Xianhe Lake, where is located in buffer zone of the Zhalong wetland reserve, was chosen as our target area.The spatial variation of nutrient substances in the shallow lakes was discussed and its influence factors were pointed out.The results showed that nitrogen and phosphorus in the wetland water existed mainly in the form of organic ones.The concentration of total nitrogen (TN) ranged from 0.65 mg/L to 10.64 mg/L and total phosphorus (TP) ranged from 0.013 mg/L to 0.052 mg/L.Ratio of N/P was between 25.6 and 206.5.The water quality of the Xianhe Lake has been contaminated and is in heavy eutrophication.Total P has been acting as the major limiting factor.The distribution pattern of nitrogen and phosphorus in wetland water showed characteristics of internal release except for the stream mouth area.There, the vertical distributions of nitrogen and phosphorus nutrients were from both exterior source and internal release, and was mainly influenced by exterior source during flood period.Strong hydrodynamic disturb contributed to nitrogen and phosphorus nutrients suspending and releasing in the sediments.The nutrients distribution in the water varied independent on regional changes of different frequency of hydrodynamic disturb.Mineralization and denitrification might be promoted in high frequency hydrodynamic disturb area.In growing period, the absorption of Phragmites to nutrients was an important mechanism of nutrients descending and spatial variation in the shallow lake.

  19. Cryptococcus neoformans requires the ESCRT protein Vps23 for iron acquisition from heme, for capsule formation, and for virulence.

    Hu, Guanggan; Caza, Mélissa; Cadieux, Brigitte; Chan, Vivienne; Liu, Victor; Kronstad, James

    2013-01-01

    Iron availability is a key regulator of virulence factor elaboration in Cryptococcus neoformans, the causative agent of fungal meningoencephalitis in HIV/AIDS patients. In addition, iron is an essential nutrient for pathogen proliferation in mammalian hosts but little is known about the mechanisms of iron sensing and uptake in fungal pathogens that attack humans. In this study, we mutagenized C. neoformans by Agrobacterium-mediated T-DNA insertion and screened for mutants with reduced growth on heme as the sole iron source. Among 34 mutants, we identified a subset with insertions in the gene for the ESCRT-I (endosomal sorting complex required for transport) protein Vps23 that resulted in a growth defect on heme, presumably due to a defect in uptake via endocytosis or misregulation of iron acquisition from heme. Remarkably, vps23 mutants were also defective in the elaboration of the cell-associated capsular polysaccharide that is a major virulence factor, while overexpression of Vps23 resulted in cells with a slightly enlarged capsule. These phenotypes were mirrored by a virulence defect in the vps23 mutant in a mouse model of cryptococcosis and by hypervirulence of the overexpression strain. Overall, these results reveal an important role for trafficking via ESCRT functions in both heme uptake and capsule formation, and they further reinforce the connection between iron and virulence factor deployment in C. neoformans.

  20. Nutrient-dense food groups have high energy costs: an econometric approach to nutrient profiling.

    Maillot, Matthieu; Darmon, Nicole; Darmon, Michel; Lafay, Lionel; Drewnowski, Adam

    2007-07-01

    Consumers wishing to replace some of the foods in their diets with more nutrient-dense options need to be able to identify such foods on the basis of nutrient profiling. The present study used nutrient profiling to rank 7 major food groups and 25 subgroups in terms of their contribution to dietary energy, diet quality, and diet cost for 1332 adult participants in the French National INCA1 Study. Nutrient profiles were based on the presence of 23 qualifying nutrients, expressed as the percentage of nutrient adequacy per 8 MJ, and 3 negative or disqualifying nutrients, expressed as the percentage of the maximal recommended values for saturated fatty acids, added sugar, and sodium per 1.4 kg. Calculated cost of energy (euro/8 MJ) was based on the mean retail price of 619 foods in the nutrient composition database. The meat and the fruit and vegetables food groups had the highest nutritional quality but were associated with highest energy costs. Sweets and salted snacks had the lowest nutritional quality but were also one of the least expensive sources of dietary energy. Starches and grains were unique because they were low in disqualifying nutrients yet provided low-cost dietary energy. Within each major food group, some subgroups had a higher nutritient-to-price ratio than others. However, the fact that food groups with the more favorable nutrient profiles were also associated with higher energy costs suggests that the present structure of food prices may be a barrier to the adoption of food-based dietary guidelines, at least by low-income households.

  1. Language Change and Language Acquisition

    Thorbjörg Hróarsdóttir

    2004-01-01

    Full Text Available The aim of this paper is to present diachronic changes in terms of the conditions of first language acquisition. Grammars, seen as mental organs, may change between two generations. A change is initiated when (a population of learners converge on a grammatical system which differs in at least one parameter value from the system internalized by the speakers of the previous generation. Learnability issues then connect to both language acquisition and language change, and understanding language changes depends on understanding how children acquire their native language. Acquisition is a process in which Universal Grammar (UG interacts with a context-specific set of Primary Linguistic Data (PLD: the linguistic input to the child-learner and uses these PLD as the source for triggers or cues that map the innate (preexperience knowledge to a mature grammar. If a certain phenomenon has survived through many generations, it must have been reflected clearly in the PLD. Then, if we note that it has changed, something in the language performance of the previous generation must have changed, and thereby paved the way for a new interpretation. Innovation leading to linguistic variation in the PLD and gradual changes in PLD play a central role in the explanation here: the immediate cause of a grammar change must lie in some alternation in the PLD. We will look at how the language spoken in a certain community (E-language may gradually become different from the language that originally served as the triggering experience. These changes in the E-language also mean changes in the input available to the child-learners of the next generation and a motivation for a different parameter setting has arisen.

  2. Growth Culture Conditions and Nutrient Signaling Modulating Yeast Chronological Longevity

    Júlia Santos

    2012-01-01

    Full Text Available The manipulation of nutrient-signaling pathways in yeast has uncovered the impact of environmental growth conditions in longevity. Studies using calorie restriction show that reducing glucose concentration of the culture media is sufficient to increase replicative and chronological lifespan (CLS. Other components of the culture media and factors such as the products of fermentation have also been implicated in the regulation of CLS. Acidification of the culture media mainly due to acetic acid and other organic acids production negatively impacts CLS. Ethanol is another fermentative metabolite capable of inducing CLS reduction in aged cells by yet unknown mechanisms. Recently, ammonium was reported to induce cell death associated with shortening of CLS. This effect is correlated to the concentration of NH4+ added to the culture medium and is particularly evident in cells starved for auxotrophy-complementing amino acids. Studies on the nutrient-signaling pathways regulating yeast aging had a significant impact on aging-related research, providing key insights into mechanisms that modulate aging and establishing the yeast as a powerful system to extend knowledge on longevity regulation in multicellular organisms.

  3. Sinopec to Accelerate Overseas Acquisition

    2011-01-01

    As part of its strategic move to expand portfolio of overseas oil and gas reserves, Sinopec Group is now stepping up its efforts for acquisition of a Canadian oil and gas company. Daylight Energy Ltd. has recently agreed to be acquired by China's Sinopec International Petroleum Exploration and Production Corp. (SIPEPC) for about C$2.2 billion (US$2.1 billion). The deal for Calgary, Alberta-based Daylight is for C$10.08 per share.

  4. The role of submerged macrophytes and macroalgae in nutrient cycling: A budget approach

    Human, Lucienne R. D.; Snow, Gavin C.; Adams, Janine B.; Bate, Guy C.; Yang, Sheng-Chi

    2015-03-01

    This study used a budget approach to determine the effect of submerged macrophytes and macroalgae on the storage of N and P in an estuary. Above and below ground tissue content of nitrogen and phosphorus were determined for the various macrophyte species. The mouth of the estuary was artificially breached in February 2011 with a volume of 0.3 × 106 m3 and closed a week later. A 1:100 year flood with volume close to 3 × 106 m3 breached the mouth naturally in June 2011 flushing water and sediment out of the estuary. In order to track the change in the nutrient acquisition of the submerged macrophytes and macroalgae over a closed-mouth state, the nutrient budget was constructed for the period February 2011 to July 2011, from the time the mouth closed until it opened again. Relative to other inputs the sediment contributed 30% of the TN and 40% TP toward the nutrient budget, while the submerged macrophytes and macroalgae stored 20-30 % TN and 30-38 % TP. The river and precipitation contributed less than 3% of the TN and TP input. It was previously thought that the sediments of South African temporarily open/closed estuaries did not have the necessary organic stock to fuel primary production. However this research showed this to be incorrect. Submerged macrophytes and macroalgae significantly influenced nutrient cycling and this is the first detailed account of incorporating vegetation into a nutrient budget without relying solely on C:N:P ratios.

  5. Ectomycorrhizal fungal diversity, tree diversity and root nutrient relations in a mixed Central European forest.

    Lang, Christa; Polle, Andrea

    2011-05-01

    Knowledge is limited about whether root nutrient concentrations are affected by mixtures of tree species and interspecific root competition. The goal of this field study was to investigate root nutrient element concentrations in relation to root and ectomycorrhizal (EM) diversity in six different mixtures of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia sp.) in an old-growth, undisturbed forest ecosystem. Root biomass and nutrient concentrations per tree taxon as well as the abundance and identity of all EM fungi were determined in soil cores of a volume of 1 L (r=40 mm, depth=200 mm). Stand-level nutrient concentrations in overall root biomass and H' (Shannon-Wiener diversity) were obtained by pooling the data per stand. At stand level, Shannon H' for roots and aboveground tree species abundance were correlated. H' for roots and EM fungi were not correlated because of the contribution of ash roots that form only arbuscular mycorrhizal but no EM associations. Nutrient element concentrations in roots showed taxon-related differences and increased in the following order: beech ≤ lime tree diversity because of two effects: increasing contribution of ash roots to the mixture and increasing Ca accumulation in beech roots with increasing root diversity. On a small scale, increasing root diversity, but not EM diversity, was correlated with decreasing P concentrations in beech roots pointing to interspecific tree competition. Nitrogen (N) concentrations of beech roots were unaltered in relation to root and EM diversity. Opposing behavior was observed for lime and ash: the N concentrations in lime roots increased, whereas those in ash roots decreased with increasing EM diversity in a given soil volume. This suggests that EM diversity facilitates N acquisition of lime roots at the expense of non-EM ash.

  6. Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zhou, Jianmin

    2015-09-01

    Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the polyacrylate membrane, and hence to analyze the mechanism of nutrient release, Fourier transform mid-infrared spectroscopy, scanning electron microscopy, and atomic force microscopy were employed. The nutrient-release model of CRF post-treated at 30 °C was the inverse “L” curve, but an increased duration of the post-treatment had no effect. The nutrient-release model was “S” curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action. CRF equipped with specified nutrient-release behaviors can be achieved by optimizing the thermal post-treatment parameters, which can contribute to the development and application of waterborne polymer-coated CRF and controlled-release technologies.

  7. Modeling nutrient retention at the watershed scale: Does small stream research apply to the whole river network?

    Aguilera, Rosana; Marcé, Rafael; Sabater, Sergi

    2013-06-01

    are conveyed from terrestrial and upstream sources through drainage networks. Streams and rivers contribute to regulate the material exported downstream by means of transformation, storage, and removal of nutrients. It has been recently suggested that the efficiency of process rates relative to available nutrient concentration in streams eventually declines, following an efficiency loss (EL) dynamics. However, most of these predictions are based at the reach scale in pristine streams, failing to describe the role of entire river networks. Models provide the means to study nutrient cycling from the stream network perspective via upscaling to the watershed the key mechanisms occurring at the reach scale. We applied a hybrid process-based and statistical model (SPARROW, Spatially Referenced Regression on Watershed Attributes) as a heuristic approach to describe in-stream nutrient processes in a highly impaired, high stream order watershed (the Llobregat River Basin, NE Spain). The in-stream decay specifications of the model were modified to include a partial saturation effect in uptake efficiency (expressed as a power law) and better capture biological nutrient retention in river systems under high anthropogenic stress. The stream decay coefficients were statistically significant in both nitrate and phosphate models, indicating the potential role of in-stream processing in limiting nutrient export. However, the EL concept did not reliably describe the patterns of nutrient uptake efficiency for the concentration gradient and streamflow values found in the Llobregat River basin, posing in doubt its complete applicability to explain nutrient retention processes in stream networks comprising highly impaired rivers.

  8. A nutrient-sensitive interaction between Sirt1 and HNF-1α regulates Crp expression.

    Grimm, Andrew A; Brace, Cynthia S; Wang, Ting; Stormo, Gary D; Imai, Shin-ichiro

    2011-04-01

    Silent information regulator 2 (Sir2) orthologs are an evolutionarily conserved family of NAD-dependent protein deacetylases that regulate aging and longevity in model organisms. The mammalian Sir2 ortholog Sirt1 regulates metabolic and stress responses through the deacetylation of many transcriptional regulatory factors. To elucidate the mechanism by which Sirt1 controls gene expression in response to nutrient availability, we devised a bioinformatic screen combining gene expression analysis with phylogenetic footprinting to identify transcription factors as new candidate partners of Sirt1. One candidate target was HNF-1α, a homeodomain transcription factor that regulates pancreatic β-cell and hepatocyte functions and is commonly mutated in patients with maturity-onset diabetes of the young (MODY). Interestingly, Sirt1 physically interacts with HNF-1αin vitro but does so in vivo only in nutrient-restricting conditions. This interaction requires 12-24 h of nutrient restriction and is dependent on protein synthesis. Both nutrient restriction and Sirt1 suppress HNF-1α transcriptional activity and the expression of one of its target genes, C-reactive protein (Crp), in mouse primary hepatocytes. Pharmacological inhibition of Sirt1 blocks the suppression of Crp by nutrient restriction. Similarly, Crp expression is also suppressed in fasted and diet-restricted liver. Furthermore, Sirt1 and HNF-1α co-localize on two HNF-1α binding sites on the Crp promoter, leading to decreased acetylation of lysine 16 of histone H4 at these sites only in response to nutrient restriction. These findings reveal a novel nutrient-dependent interaction between Sirt1 and HNF-1α and provide important insight into the molecular mechanism by which Sirt1 mediates the anti-aging effects of diet restriction.

  9. Responses of plant nutrient resorption to phosphorus addition in freshwater marsh of Northeast China.

    Mao, Rong; Zeng, De-Hui; Zhang, Xin-Hou; Song, Chang-Chun

    2015-01-29

    Anthropogenic activities have increased phosphorus (P) inputs to most aquatic and terrestrial ecosystems. However, the relationship between plant nutrient resorption and P availability is still unclear, and much less is known about the underlying mechanisms. Here, we used a multi-level P addition experiment (0, 1.2, 4.8, and 9.6 g P m(-2) year(-1)) to assess the effect of P enrichment on nutrient resorption at plant organ, species, and community levels in a freshwater marsh of Northeast China. The response of nutrient resorption to P addition generally did not vary with addition rates. Moreover, nutrient resorption exhibited similar responses to P addition across the three hierarchical levels. Specifically, P addition decreased nitrogen (N) resorption proficiency, P resorption efficiency and proficiency, but did not impact N resorption efficiency. In addition, P resorption efficiency and proficiency were linearly related to the ratio of inorganic P to organic P and organic P fraction in mature plant organs, respectively. Our findings suggest that the allocation pattern of plant P between inorganic and organic P fractions is an underlying mechanism controlling P resorption processes, and that P enrichment could strongly influence plant-mediated biogeochemical cycles through altered nutrient resorption in the freshwater wetlands of Northeast China.

  10. Responses of plant nutrient resorption to phosphorus addition in freshwater marsh of Northeast China

    Mao, Rong; Zeng, De-Hui; Zhang, Xin-Hou; Song, Chang-Chun

    2015-01-01

    Anthropogenic activities have increased phosphorus (P) inputs to most aquatic and terrestrial ecosystems. However, the relationship between plant nutrient resorption and P availability is still unclear, and much less is known about the underlying mechanisms. Here, we used a multi-level P addition experiment (0, 1.2, 4.8, and 9.6 g P m-2 year-1) to assess the effect of P enrichment on nutrient resorption at plant organ, species, and community levels in a freshwater marsh of Northeast China. The response of nutrient resorption to P addition generally did not vary with addition rates. Moreover, nutrient resorption exhibited similar responses to P addition across the three hierarchical levels. Specifically, P addition decreased nitrogen (N) resorption proficiency, P resorption efficiency and proficiency, but did not impact N resorption efficiency. In addition, P resorption efficiency and proficiency were linearly related to the ratio of inorganic P to organic P and organic P fraction in mature plant organs, respectively. Our findings suggest that the allocation pattern of plant P between inorganic and organic P fractions is an underlying mechanism controlling P resorption processes, and that P enrichment could strongly influence plant-mediated biogeochemical cycles through altered nutrient resorption in the freshwater wetlands of Northeast China.

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

    Hrechana Svitlana I.

    2014-03-01

    Full Text Available 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 mechanisms of their realisation from the position of practice of developed countries and trans-national corporations and also domestic associations of enterprises. It shows that transactions of tough or forced character of acquisition prevail in Ukraine, specific features of which are not only the reduced cost but also direct belonging of buyers to oligarchic-political structures. It explains negative influence of these specific features upon volume and activity of the national M and A market. It formulates and offers a system of state and economic subjects measures, immediate application of which would allow creation of favourable conditions for development of the national merger and acquisition market.

  12. Sample Acquisition and Instrument Deployment (SAID)

    Boyd, Robert C.

    1994-11-01

    This report details the interim progress for contract NASW-4818, Sample Acquisition and Instrument Deployment (SAID), a robotic system for deploying science instruments and acquiring samples for analysis. The system is a conventional four degree of freedom manipulator 2 meters in length. A baseline design has been achieved through analysis and trade studies. The design considers environmental operating conditions on the surface of Mars, as well as volume constraints on proposed Mars landers. Control issues have also been studied, and simulations of joint and tip movements have been performed. A passively braked shape memory actuator with the ability to measure load has been developed. The wrist also contains a mechanism which locks the lid output to the bucket so that objects can be grasped and released for instrument deployment. The wrist actuator has been tested for operational power and mechanical functionality at Mars environmental conditions. The torque which the actuator can produce has been measured. Also, testing in Mars analogous soils has been performed.

  13. Blade life span, structural investment, and nutrient allocation in giant kelp.

    Rodriguez, Gabriel E; Reed, Daniel C; Holbrook, Sally J

    2016-10-01

    The turnover of plant biomass largely determines the amount of energy flowing through an ecosystem and understanding the processes that regulate turnover has been of interest to ecologists for decades. Leaf life span theory has proven useful in explaining patterns of leaf turnover in relation to resource availability, but the predictions of this theory have not been tested for macroalgae. We measured blade life span, size, thickness, nitrogen content, pigment content, and maximum photosynthetic rate (P max) in the giant kelp (Macrocystis pyrifera) along a strong resource (light) gradient to test whether the predictions of leaf life span theory applied to this alga. We found that shorter blade life spans and larger blade areas were associated with increased light availability. In addition, nitrogen and P max decreased with blade age, and their decrease was greater in shorter lived blades. These observations are generally consistent with patterns observed for higher plants and the prevailing theory of leaf life span. By contrast, variation observed in pigments of giant kelp was inconsistent with that predicted by leaf life span theory, as blades growing in the most heavily shaded portion of the forest had the lowest chlorophyll content. This result may reflect the dual role of macroalgal blades in carbon fixation and nutrient absorption and the ability of giant kelp to modify blade physiology to optimize the acquisition of light and nutrients. Thus, the marine environment may place demands on resource acquisition and allocation that have not been previously considered with respect to leaf life span optimization.

  14. Web-based data acquisition

    胡旭东; 俞红; 陈鹰

    2002-01-01

    The research work on Web-based long-distance data acquisition (DAQ) is valuable for application to tele-detection machine faults. With an expert system for machine fault detection, faults in a distantly located machine can be diagnosed through the internet. The distant user logs on to the expert system Web page, fills in the requirements, and starts-up the diagnose process. The system then connects to the DAQ server that is installed in the machine, samples data required for diagnoses through the internet, and sends back diagnose results. In such a long-distance system, Web-based DAQ plays an important role by automatic sampling and transferring of data through the internet. We have built an experimental data acquisition system using a National Instruments AT-MIO-16E-10 board running under Ch language environment. In this experimental example, the user can acquire data online. The principle of this experimental method is introduced in this paper. A detailed programming technique is described with an example.

  15. Acquisition of English comparative adjectives.

    Graziano-King, Janine; Cairns, Helen Smith

    2005-05-01

    Two experiments investigated the acquisition of English comparative adjective forms, Adj + er and more Adj. In Experiment 1, 72 children, four- and seven-years-old, indicated their preferences for the synthetic or periphrastic comparative form for 16 adjectives in a forced-choice judgement task; their responses were compared to those of a group of adults (Graziano-King, 2003). In Experiment 2, a group of 29 children, ranging in age from 5;1 to 10;9, and a group of 11 adults performed a forced-choice judgement task, similar to that of Experiment 1, and an elicited production task, responding to the same 32 adjectives for both tasks. The two studies together support an acquisition trajectory of three stages. In the first stage, children show no preference for either form of the comparative; in the second, they adopt a suffixation rule; and in the third, they abandon the general rule and become conservative learners, eventually reaching the adult target.

  16. Characterization of nutrient deficiency in Hancornia speciosa Gomes seedlings by omitting micronutrients from the nutrient solution

    Layara Alexandre Bessa

    2013-06-01

    Full Text Available Hancornia speciosa Gomes (Mangaba tree is a fruit tree belonging to the Apocynaceae family and is native to Brazil. The production of seedlings of this species is limited by a lack of technical and nutritional expertise. To address this deficiency, this study aimed to characterize the visual symptoms of micronutrient deficiency and to assess growth and leaf nutrient accumulation in H. speciosa seedlings supplied with nutrient solutions that lack individual micronutrients. H. speciosa plants were grown in nutrient solution in a greenhouse according to a randomized block design, with four replicates. The treatments consisted of a group receiving complete nutrient solution and groups treated with a nutrient solution lacking one of the following micronutrients: boron (B, copper (Cu, iron (Fe, manganese (Mn, zinc (Zn, and molybdenum (Mo. The visual symptoms of nutrient deficiency were generally easy to characterize. Dry matter production was affected by the omission of micronutrients, and the treatment lacking Fe most limited the stem length, stem diameter, root length, and number of leaves in H. speciosa seedlings as well as the dry weight of leaves, the total dry weight, and the relative growth in H. speciosa plants. The micronutrient contents of H. speciosa leaves from plants receiving the complete nutrient solution treatment were, in decreasing order, Fe>Mn>Cu>Zn>B.

  17. Data acquisition with direct memory access

    Iu. Guzun

    1999-08-01

    Full Text Available This paper is concerned about using Direct Memory Access (DMA transfer for real-time data acquisitions from a plug-in data acquisition board Aquarius DSP-1. Since the conversion speed of the modern Analog to Digital Converters is increasevealy, the using of the interrupts for reading of the conversion results becomes impossible. For the data acquisition system, presented in this paper, this speed is up to 100 kS/s. This problem can be successfully solved using DMA technique. We subsequently describe the hardware of the data acquisition board, which has been used to acquire data. Next, have been presented the functions, in C programming language, for programming a data acquisition via DMA. Finally, we present some results obtained using this kind of data acquisitions, and some conclusions.

  18. Acquisition of the Korean Imperfective Aspect Markers "-ko iss-" and "-a iss-" by Japanese Learners: A Multiple-Factor Account

    Ryu, Ju-Yeon; Horie, Kaoru; Shirai, Yasuhiro

    2015-01-01

    Although cross-linguistic research on second language tense-aspect acquisition has uncovered universal tendencies concerning the association between verbal semantics and tense-aspect markers, it is still unclear what mechanisms underlie this link. This study investigates the acquisition of two imperfective aspect markers ("-ko iss-" and…

  19. Review of L2 Vocabulary Acquisition Studies

    周先军

    2014-01-01

    Vocabulary is important in language and language acquisition, but it did not catch as much attention as it deserved for a long time. In this thesis, I’ll go through changes of vocabulary studied in linguistics and language teaching as well as rise of L2 vocabulary acquisition studies. Several aspects of L2 vocabulary acquisition studies will then be reviewed .Issues that need to be further studied will at last be put forward.

  20. On Vocabulary Acquisition by Chinese Learners

    崔莉; 南二丽

    2006-01-01

    It is admitted that vocabulary acquisition, as the smallest unit in English leaning, is the most basic, decisive yet difficult part. Yet vocabulary acquisition has always obsessed and fascinated Chinese learners of English. This paper mainly presents a discussion of English vocabulary acquisition by Chinese learners in the respect of vocabulary size and correct use. Through the analysis of the problems existing in the present vocabulary learning and teaching, author also presents some learning strategies to expand vocabulary size.

  1. Towards a Theory of Language Acquisition

    Kampen, Jacqueline van

    2008-01-01

    "We have seen at the workshop a diversity of measurements and a no less diverse amount of different phenomena. Shared areas were acquisition phenomena in Romance languages and more general: the beginnings for a true theory of language acquisition. I will not attempt to evaluate the various contributions here. All of this must get its time to sink in. Yet, the general point of our endeavors, - the theory of language acquisition -, may be underlined to gain a further outlook"

  2. Lexicon acquisition in an interdisciplinary learning context

    MARIA PAULA SANTOS SOARES DA SILVA LAGO

    2013-12-01

    Full Text Available This paper presents the questions that led to the field research, the theoretical frame, the subsequent methodology, and some of the results and conclusions. One of these conclusions is the need of specific tasks aimed at lexicon acquisition and of interdisciplinary work within that acquisition. Some strategies of minimizing failure and e learning enhancement will also be discussed, as well as the learning results achieved in the strict area of lexicon acquisition.

  3. Review of L2 Vocabulary Acquisition Studies

    周先军

    2014-01-01

    Vocabulary is important in language and language acquisition, but it did not catch as much attention as it deserved for a long time. In this thesis, I’ll go through changes of vocabulary studied in linguistics and language teaching as well as rise of L2 vocabulary acquisition studies. Several aspects of L2 vocabulary acquisition studies will then be reviewed.Issues that need to be further studied will at last be put forward.

  4. Technological Integration of Acquisitions in Digital Industries

    Henningsson, Stefan; Toppenberg, Gustav

    2015-01-01

    Acquisitions have become essential tools to retain the technological edge in digital industries. This paper analyses the technological integration challenges in such acquisitions. Acquirers in digital industries are typically platform leaders in platform markets. They acquire (a) other platform...... providers to extend the platform core and to derive network effects by consolidating platform user groups, and (b) complement providers to create monopoly positions for the complements and for innovation complementarity. To enable these acquisition benefits, acquirers face technological integration...

  5. Molecular mechanism of acquisition of the cholera toxin genes.

    Das, Bhabatosh; Bischerour, Julien; Barre, Francois-Xavier

    2011-02-01

    One of the major pathogenic determinants of Vibrio cholerae, the cholera toxin, is encoded in the genome of a filamentous phage, CTXφ. CTXφ makes use of the chromosome dimer resolution system of V. cholerae to integrate its single stranded genome into one, the other, or both V. cholerae chromosomes. Here, we review current knowledge about this smart integration process.

  6. Learning the manifold of quality ultrasound acquisition.

    El-Zehiry, Noha; Yan, Michelle; Good, Sara; Fang, Tong; Zhou, S Kevin; Grady, Leo

    2013-01-01

    Ultrasound acquisition is a challenging task that requires simultaneous adjustment of several acquisition parameters (the depth, the focus, the frequency and its operation mode). If the acquisition parameters are not properly chosen, the resulting image will have a poor quality and will degrade the patient diagnosis and treatment workflow. Several hardware-based systems for autotuning the acquisition parameters have been previously proposed, but these solutions were largely abandoned because they failed to properly account for tissue inhomogeneity and other patient-specific characteristics. Consequently, in routine practice the clinician either uses population-based parameter presets or manually adjusts the acquisition parameters for each patient during the scan. In this paper, we revisit the problem of autotuning the acquisition parameters by taking a completely novel approach and producing a solution based on image analytics. Our solution is inspired by the autofocus capability of conventional digital cameras, but is significantly more challenging because the number of acquisition parameters is large and the determination of "good quality" images is more difficult to assess. Surprisingly, we show that the set of acquisition parameters which produce images that are favored by clinicians comprise a 1D manifold, allowing for a real-time optimization to maximize image quality. We demonstrate our method for acquisition parameter autotuning on several live patients, showing that our system can start with a poor initial set of parameters and automatically optimize the parameters to produce high quality images.

  7. Acquisition in different and special subject areas

    Katz, Linda S

    2013-01-01

    Learn how acquisitions librarians successfully serve specialized users! In this book, you'll find profiles, methods, and processes for acquisitions in specialized subject areas, such as local and regional poetry, oceanography, educational information in electronic formats, popular fiction, regional and ethnic materials, and more. Seasoned acquisitions librarians share their experiences in gathering the hard-to-find materials their libraries' highly specialized clients need to access. You'll also examine issues surrounding the acquisition of new reference tools that are vital in today's emergi

  8. Pragmatic Transfer in Second Language Acquisition

    李婷

    2011-01-01

    Pragmatic.transfer is a common phenomenon that exists in Second Language Acquisition. It is an increasingly important .research of interlanguage pragmatics in the last two decades. Based on the characteristics , it plays an important role in the success of cultural communication and Second Language Acquisition. Based on presenting the concept of pragmatic transfer, this paper presents the concept of pragmatic transfer in second language acquisition and introduces the classification of pragmatic transfer. Then, this paper proposes some suggestions to avoid negative pragmatic transfer in second language acquisition. It is hoped that this paper can help second language learners to develop their communicative competence and avoid pragmatic failures in intercultural communication.

  9. IT Consultants in Acquisition IT Integration

    Henningsson, Stefan; Øhrgaard, Christian

    2016-01-01

    ’s IT following a corporate acquisition, presents a difficult but crucial IT challenge for the many acquiring organizations. Through a comparative case study of four acquirers, theoretically grounded in the resource-based view of the firm, it is analyzed how acquirers draw on external consultants to realize...... model, depicting the use of external consultants in acquisition IT integration, contributes to the literature on acquisition IT integration by providing an explanation for IT-based value creation in acquisition that is rooted in the external of the acquirer. In addition to adding to the limited...

  10. Biological Nutrient Removal in Compact Biofilm Systems

    Bassin, J.P.

    2012-01-01

    The removal of nutrients such as nitrogen and phosphorus from both domestic and industrial wastewaters is imperative since they potentially harm the environment. One of the main consequences of excessive availability of nitrogen and phosphorus in aquatic ecosystems (freshwater, marine and estuarine)

  11. Breast milk nutrient content and infancy growth

    Prentice, Philippa; Ong, Ken K.; Schoemaker, Marieke H.; Tol, van Eric A.F.; Vervoort, Jacques; Hughes, Ieuan A.; Acerini, Carlo L.; Dunger, David B.

    2016-01-01

    Aim: Benefits of human breast milk (HM) in avoiding rapid infancy weight gain and later obesity could relate to its nutrient content. We tested the hypothesis that differential HM total calorie content (TCC) or macronutrient contents may be associated with infancy growth. Methods: HM hindmilk sam

  12. NUTRIENTS AND EPIGENETICS IN BOVINE CELLS

    This is a chapter for a book titled “Livestock Epigenetics” edited by Dr. Hasan Khatib and published by Wiley-Blackwell. This chapter is focused on the research development in our laboratory in the area of interaction of nutrients and genomic phonotype in bovine cells. Briefly, the Research on nutri...

  13. Usefulness of Models in Precision Nutrient Management

    Plauborg, Finn; Manevski, Kiril; Zhenjiang, Zhou

    and mineral composition. Mapping of crop status and the spatial-temporal variability within fields with red-infrared reflection are used to support decision on split fertilisation and more precise dosing. The interpretation and use of these various data in precise nutrient management is not straightforward...

  14. Nutrient Digestion and Utilization in Farm Animals

    Kebreab, E.; Dijkstra, J.; Bannink, A.; Gerrits, W.J.J.; France, J.

    2006-01-01

    The purpose of this book is to present current research in modelling nutrient digestion and utilization in cattle, sheep, pigs, poultry and fish. The book is organised into six sections that cover a range of topics and modelling approaches; these are (i) absorption and passage; (ii) growth and devel

  15. Nutrient cycling and foodwebs in Dutch estuaries

    Nienhuis, P.H.

    1993-01-01

    In this review several aspects of the functioning of the Dutch estuaries (Ems-Dollard, Wadden Sea, Oosterschelde, Westerschelde, Grevelingen and Veerse Meer) have been compared. A number of large European rivers (especially Rhine) have a prevailing influence on the nutrient cycling of most Dutch est

  16. Autonomous Surface Sample Acquisition for Planetary and Lunar Exploration

    Barnes, D. P.

    2007-08-01

    network, and constitute the science targets for our autonomous sample acquisition work. Our PAT Lab. terrain has been designed to support our new rover chassis which is based upon the ExoMars rover Concept-E mechanics which were investigated during the ESA ExoMars Phase A study. The rover has 6 wheel drives, 6 wheels steering, and a 6 wheel walking capability. Mounted on the rover chassis is the UWA robotic arm and mast. We have designed and built a PanCam system complete with a computer controlled pan and tilt mechanism. The UWA PanCam is based upon the ExoMars PanCam (Phase A study) and hence supports two Wide Angle Cameras (WAC - 64 degree FOV), and a High Resolution Camera (HRC - 5 degree FOV). WAC separation is 500 mm. Software has been developed to capture images which form the data input into our on-board autonomous surface sample acquisition algorithms.

  17. Acquisition Management for System-of-Systems: Requirement Evolution and Acquisition Strategy Planning

    2012-04-30

    Director, Office of Acquisition Resources and Analysis ( ARA )  Deputy Assistant Secretary of the Navy, Acquisition & Procurement  Director of Open...geographically distributed, heterogeneous , collaborative systems that demonstrate operational and managerial independences. The collaboration can be

  18. Evaluation of nutrient specifications for broiler breeders.

    Wilson, H R; Harms, R H

    1984-07-01

    Two experiments were conducted to determine if previously suggested nutrient requirements of broiler breeders (23 g protein, 850 mg sulfur amino acids, 4.5 g calcium, and 750 mg phosphorus/bird/day) are in excess and could be reduced during the laying period. In Experiment 1, Cobb color-sex broiler breeders were fed daily nutrient allowances that were 100.0, 96.3, 92.5, 89.4, and 86.6% of the suggested requirements. In Experiment 2, Cobb feather-sex breeders were fed daily allowances that were 92.5, 89.4, 86.6, 83.4, and 80.9% of the suggested requirements. Birds on all diets were fed the same energy level; however, energy varied with season to maintain body weight. Egg production, fertility, hatchability, egg weight, and shell quality were not significantly affected by the reductions in nutrient intake in either experiment. The diet with the lowest nutrient level (80.9% of the suggested requirement) was adequate, indicating a considerable margin of safety for the stated requirements. Body weight was quite variable but tended to decrease with nutrient restriction. Weights of broilers hatched from treated breeders were not significantly affected at 49 days of age by the breeder dietary treatments. These results indicate that broiler breeder diets formulated to meet presently suggested requirements have a large margin of safety and a reduction of specifications by approximately 10% is suggested. The revised daily intakes recommended are: 20.6 g protein, 754 mg sulfur amino acids, 400 mg methionine, 938 mg lysine, 1379 mg arginine, 256 mg tryptophan, 4.07 g calcium, 683 mg total phosphorus, and 170 mg sodium.

  19. Nutrient Status of Adults with Cystic Fibrosis

    GORDON, CATHERINE M.; ANDERSON, ELLEN J.; HERLYN, KAREN; HUBBARD, JANE L.; PIZZO, ANGELA; GELBARD, RONDI; LAPEY, ALLEN; MERKEL, PETER A.

    2011-01-01

    Nutrition is thought to influence disease status in patients with cystic fibrosis (CF). This cross-sectional study sought to evaluate nutrient intake and anthropometric data from 64 adult outpatients with cystic fibrosis. Nutrient intake from food and supplements was compared with the Dietary Reference Intakes for 16 nutrients and outcomes influenced by nutritional status. Attention was given to vitamin D and calcium given potential skeletal implications due to cystic fibrosis. Measurements included weight, height, body composition, pulmonary function, and serum metabolic parameters. Participants were interviewed about dietary intake, supplement use, pulmonary function, sunlight exposure, and pain. The participants’ mean body mass index (±standard deviation) was 21.8±4.9 and pulmonary function tests were normal. Seventy-eight percent used pancreatic enzyme replacement for malabsorption. Vitamin D deficiency [25-hydroxyvitamin D (25OHD)<37.5 nmol/L] was common: 25 (39%) were deficient despite adequate vitamin D intake. Lipid profiles were normal in the majority, even though total and saturated fat consumption represented 33.0% and 16.8% of energy intake, respectively. Reported protein intake represented 16.9% of total energy intake (range 10%–25%). For several nutrients, including vitamin D and calcium, intake from food and supplements in many participants exceeded recommended Tolerable Upper Intake Levels. Among adults with cystic fibrosis, vitamin D deficiency was common despite reported adequate intake, and lipid profiles were normal despite a relatively high fat intake. Mean protein consumption was adequate, but the range of intake was concerning, as both inadequate or excessive intake may have deleterious skeletal effects. These findings call into question the applicability of established nutrient thresholds for patients with cystic fibrosis. PMID:18060897

  20. Plant traits mediate consumer and nutrient control on plant community productivity and diversity.

    Eskelinen, Anu; Harrison, Susan; Tuomi, Maria

    2012-12-01

    The interactive effects of consumers and nutrients on terrestrial plant communities, and the role of plant functional traits in mediating these responses, are poorly known. We carried out a six-year full-factorial field experiment using mammalian herbivore exclusion and fertilization in two habitat types (fertile and infertile alpine tundra heaths) that differed in plant functional traits related to resource acquisition and palatability. Infertile habitats were dominated by species with traits indicative of a slow-growing strategy: high C:N ratio, low specific leaf area, and high condensed tannins. We found that herbivory counteracted the effect of fertilization on biomass, and that this response differed between the two habitats and was correlated with plant functional traits. Live biomass dominated the treatment responses in infertile habitats, whereas litter accumulation dominated the treatment responses in fertile habitats and was strongly negatively associated with resident community tannin concentration. Species richness declined under herbivore exclusion and fertilization in fertile habitats, where litter accumulation was greatest. Community means of plant C:N ratio predicted treatment effects on diversity: fertilization decreased and herbivory increased dominance in communities originally dominated by plants with high C:N, while fertilization increased and herbivory diminished dominance in communities where low C:N species were abundant. Our results highlight the close interdependence between consumer effects, soil nutrients, and plant functional traits and suggest that plant traits may provide an improved understanding of how consumers and nutrients influence plant community productivity and diversity.

  1. Context-specific comparison of sleep acquisition systems in Drosophila

    David S. Garbe

    2015-11-01

    Full Text Available Sleep is conserved across phyla and can be measured through electrophysiological or behavioral characteristics. The fruit fly, Drosophila melanogaster, provides an excellent model for investigating the genetic and neural mechanisms that regulate sleep. Multiple systems exist for measuring fly activity, including video analysis and single-beam (SB or multi-beam (MB infrared (IR-based monitoring. In this study, we compare multiple sleep parameters of individual flies using a custom-built video-based acquisition system, and commercially available SB- or MB-IR acquisition systems. We report that all three monitoring systems appear sufficiently sensitive to detect changes in sleep duration associated with diet, age, and mating status. Our data also demonstrate that MB-IR detection appeared more sensitive than the SB-IR for detecting baseline nuances in sleep architecture, while architectural changes associated with varying life-history and environment were generally detected across all acquisition types. Finally, video recording of flies in an arena allowed us to measure the effect of ambient environment on sleep. These experiments demonstrate a robust effect of arena shape and size as well as light levels on sleep duration and architecture, and highlighting the versatility of tracking-based sleep acquisition. These findings provide insight into the context-specific basis for choosing between Drosophila sleep acquisition systems, describe a novel cost-effective system for video tracking, and characterize sleep analysis using the MB-IR sleep analysis. Further, we describe a modified dark-place preference sleep assay using video tracking, confirming that flies prefer to sleep in dark locations.

  2. Language acquisition is language change.

    Crain, Stephen; Goro, Takuya; Thornton, Rosalind

    2006-01-01

    According to the theory of Universal Grammar, the primary linguistic data guides children through an innately specified space of hypotheses. On this view, similarities between child-English and adult-German are as unsurprising as similarities between cousins who have never met. By contrast, experience-based approaches to language acquisition contend that child language matches the input, with nonadult forms being simply less articulated versions of the forms produced by adults. This paper reports several studies that provide support for the theory of Universal grammar, and resist explanation on experience-based accounts. Two studies investigate English-speaking children's productions, and a third examines the interpretation of sentences by Japanese speaking children. When considered against the input children are exposed to, the findings of these and other studies are consistent with the continuity hypothesis, which supposes that child language can differ from the language spoken by adults only in ways that adult languages can differ from each other.

  3. CEBAF Distributed Data Acquisition System

    Allison, Trent

    2005-01-01

    There are thousands of signals distributed throughout Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) that are useful for troubleshooting and identifying instabilities. Many of these signals are only available locally or monitored by systems with small bandwidths that cannot identify fast transients. The Distributed Data Acquisition (Dist DAQ) system will sample and record these signals simultaneously at rates up to 40 Msps. Its primary function will be to provide waveform records from signals throughout CEBAF to the Experimental Physics and Industrial Control System (EPICS). The waveforms will be collected after the occurrence of an event trigger. These triggers will be derived from signals such as periodic timers or accelerator faults. The waveform data can then be processed to quickly identify beam transport issues, thus reducing down time and increasing CEBAF performance. The Dist DAQ system will be comprised of multiple standalone chassis distributed throughout CEBAF. They will be i...

  4. Early passive acquisition in Inuktitut.

    Allen, S E; Crago, M B

    1996-02-01

    Passive structures are typically assumed to be one of the later acquired constructions in child language. English-speaking children have been shown to produce and comprehend their first simple passive structures productively by about age four and to master more complex structures by about age nine. Recent crosslinguistic data have shown that this pattern may not hold across languages of varying structures. This paper presents data from four Inuit children aged 2;0 to 3;6 that shows relatively early acquisition of both simple and complex forms of the passive. Within this age range children are productively producing truncated, full, action and experiential passives. Some possible reasons for this precociousness are explored including adult input and language structure.

  5. The Acquisition Experiences of Kazoil

    Minbaeva, Dana; Muratbekova-Touron, Maral

    2016-01-01

    This case describes two diverging post-acquisition experiences of KazOil, an oil drilling company in Kazakhstan, in the years after the dissolution of the Soviet Union. When the company was bought by the Canadian corporation Hydrocarbons Ltd in 1996, exposed to new human resource strategies...... and corporate culture and management style, it seemed to adapt more successfully than in 2005, when China Petrol acquired the assets. The case opens up with Nurlan - a company’s long-time employee - reflecting on the recently introduced changes by the Chinese management, wondering how he should adapt in order...... to ensure employee’s motivation despite the lack of corporate spirit. The case can be taught in a broad range of university level courses, covering the spectrum from pure strategy and human resources management to cross-cultural management courses. The lecturer should use this case to sharpen awareness...

  6. Optimality theory in phonological acquisition.

    Barlow, J A; Gierut, J A

    1999-12-01

    This tutorial presents an introduction to the contemporary linguistic framework known as optimality theory (OT). The basic assumptions of this constraint-based theory as a general model of grammar are first outlined, with formal notation being defined and illustrated. Concepts unique to the theory, including "emergence of the unmarked," are also described. OT is then examined more specifically within the context of phonological acquisition. The theory is applied in descriptions of children's common error patterns, observed inter- and intrachild variation, and productive change over time. The particular error patterns of fronting, stopping, final-consonant deletion, and cluster simplification are considered from an OT perspective. The discussion concludes with potential clinical applications and extensions of the theory to the diagnosis and treatment of children with functional phonological disorders.

  7. Electric vehicle data acquisition system

    Svendsen, Mathias; Winther-Jensen, Mads; Pedersen, Anders Bro

    2014-01-01

    and industrial applications, e.g. research in electric vehicle driving patterns, vehicle substitutability analysis and fleet management. The platform is based on a embedded computer running Linux, and features a high level of modularity and flexibility. The system operates independently of the make of the car......, by using the On-board Diagnostic port to identify car model and adapt its software accordingly. By utilizing on-board Global Navigation Satellite System, General Packet Radio Service, accelerometer, gyroscope and magnetometer, the system not only provides valuable data for research in the field of electric......A data acquisition system for electric vehicles is presented. The system connects to the On-board Diagnostic port of newer vehicles, and utilizes the in-vehicle sensor network, as well as auxiliary sensors, to gather data. Data is transmitted continuously to a central database for academic...

  8. Deeper snow alters soil nutrient availability and leaf nutrient status in high Arctic tundra

    Semenchuk, Philipp R.; Elberling, Bo; Amtorp, Cecilie;

    2015-01-01

    Nitrogen (N) mineralization, nutrient availability, and plant growth in the Arctic are often restricted by low temperatures. Predicted increases of cold-season temperatures may be important for plant nutrient availability and growth, given that N mineralization is also taking place during the cold...... season. Changing nutrient availability may be reflected in plant N and chlorophyll content and lead to increased photosynthetic capacity, plant growth, and ultimately carbon (C) assimilation by plants. In this study, we increased snow depth and thereby cold-season soil temperatures in high Arctic......, Bistorta vivipara, and Luzula arcuata at peak season. Nutrient availability was significantly higher with increased snow depth in the two mesic meadow vegetation types, but not in the drier heath vegetation. Nitrogen concentrations and delta N-15 values of Salix leaves were significantly higher in all...

  9. Biological wastewater treatment. II Nutrient elimination; Tratamiento biologico de aguas residuales. II Eliminacion de nutrientes

    Arnaiz, C.; Isac, L.; Lebrato, J. [Universidad de Sevilla (Spain)

    2000-07-01

    Most biological wastewater processes are designed for carbonaceous compounds removal. In some cases, nutrient removal is required. In this work, biodiversity and microbial interactions of nitrogen and phosphorus removal are described. (Author) 12 refs.

  10. Plasticity of the Arabidopsis root system under nutrient deficiencies.

    Gruber, Benjamin D; Giehl, Ricardo F H; Friedel, Swetlana; von Wirén, Nicolaus

    2013-09-01

    Plant roots show a particularly high variation in their morphological response to different nutrient deficiencies. Although such changes often determine the nutrient efficiency or stress tolerance of plants, it is surprising that a comprehensive and comparative analysis of root morphological responses to different nutrient deficiencies has not yet been conducted. Since one reason for this is an inherent difficulty in obtaining nutrient-deficient conditions in agar culture, we first identified conditions appropriate for producing nutrient-deficient plants on agar plates. Based on a careful selection of agar specifically for each nutrient being considered, we grew Arabidopsis (Arabidopsis thaliana) plants at four levels of deficiency for 12 nutrients and quantified seven root traits. In combination with measurements of biomass and elemental concentrations, we observed that the nutritional status and type of nutrient determined the extent and type of changes in root system architecture (RSA). The independent regulation of individual root traits further pointed to a differential sensitivity of root tissues to nutrient limitations. To capture the variation in RSA under different nutrient supplies, we used principal component analysis and developed a root plasticity chart representing the overall modulations in RSA under a given treatment. This systematic comparison of RSA responses to nutrient deficiencies provides a comprehensive view of the overall changes in root plasticity induced by the deficiency of single nutrients and provides a solid basis for the identification of nutrient-sensitive steps in the root developmental program.

  11. Nutrient deifciency limits population development, yield formation, and nutrient uptake of direct sown winter oilseed rape

    WANG Yin; LIU Tao; LI Xiao-kun; REN Tao; CONG Ri-huan; LU Jian-wei

    2015-01-01

    Direct-sowing establishment method has great signiifcance in improving winter oilseed rape (Brassica napus L.) production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape (DOR) performance and population development dynamic are stil not wel understood. Therefore, ifve on-farm experiments were conducted in the reaches of the Yangtze River (RYR) to determine the effects of nitrogen (N), phosphorus (P), and potassium (K) deifciencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment (NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1) and three nutrient deifciency treatments based on the NPK treatment, i.e.,–N,–P, and–K. The results indicated that DOR population density declined gradual y throughout the growing season, especial y at over-wintering and pod-development stages. Nutrient deifciency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deifciency treatment. Averaged across al the experiments, seed yield reduced 61% by N deifciency, 38.3% by P deifciency, and 14.4% by K deifciency. The negative effects of nutrient deifciency on DOR performances fol owed the order of–N>–P>–K, and the effects were various among different nutrient deifciencies. Although N deifciency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deifciency signiifcantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deifciency mainly decreased individual growth and yield, but

  12. 77 FR 19975 - VA Acquisition Regulation: Simplified Acquisition Procedures for Health-Care Resources (Section...

    2012-04-03

    ... acquisition of health-care resources, consisting of commercial services or the use of medical equipment or... Service (003A2A), Office of Acquisition, Logistics and Construction, Department of Veterans Affairs, 810... rule only applies to competitive acquisitions of commercial services or the use of medical equipment...

  13. 76 FR 44293 - Defense Acquisition Regulations System; Defense Federal Acquisition Regulation Supplement; Only...

    2011-07-25

    ... presented by the Under Secretary of Defense for Acquisition, Technology, & Logistics in a memorandum dated... offered price. These provisions must also be used in acquisitions of commercial items conducted using part...--ACQUISITION OF COMMERCIAL ITEMS 4. Add new section 212.205 to read as follows: 212.205 Offers. (c) When...

  14. 75 FR 8272 - Defense Federal Acquisition Regulation Supplement; Acquisition Strategies To Ensure Competition...

    2010-02-24

    ... Regulation Supplement; Acquisition Strategies To Ensure Competition Throughout the Life Cycle of Major... Reform Act of 2009, section 202, Acquisition Strategies to Ensure Competition throughout the Lifecycle of... requirements. Section 202 directs the Secretary of Defense (SECDEF) to ensure that the acquisition strategy...

  15. The Status of Functional Categories in Child Second Language Acquisition: Evidence from the Acquisition of CP.

    Haznedar, Belma

    2003-01-01

    Examines the status of the functional categories in child second language (L2) acquisition of English. Results from longitudinally-collected data are reported, presenting counterevidence for recent hypotheses on early L2 acquisition that assume the following: (1) structure building approach according to which the acquisition of functional…

  16. 78 FR 13544 - Defense Federal Acquisition Regulation Supplement: Acquisition of Tents and Other Temporary...

    2013-02-28

    ... Acquisition Regulation Supplement: Acquisition of Tents and Other Temporary Structures (DFARS Case 2012-D015... the National Defense Authorization Act for Fiscal Year 2012 that address the acquisition of tents and... contracts that provide the best value, when acquiring tents and other temporary structures, regardless...

  17. Perception of Teachers and Administrators on the Teaching Methods That Influence the Acquisition of Generic Skills

    Audu, R.; Bin Kamin, Yusri; Bin Musta'amal, Aede Hatib; Bin Saud, Muhammad Sukri; Hamid, Mohd. Zolkifli Abd.

    2014-01-01

    This study is designed to identify the most significant teaching methods that influence the acquisition of generic skills of mechanical engineering trades students at technical college level. Descriptive survey research design was utilized in carrying out the study. One hundred and ninety (190) respondents comprised of mechanical engineering…

  18. The acquisition of phototrophy: adaptive strategies of hosting endosymbionts and organelles.

    Johnson, Matthew D

    2011-01-01

    Many non-photosynthetic species of protists and metazoans are capable of hosting viable algal endosymbionts or their organelles through adaptations of phagocytic pathways. A form of mixotrophy combining phototrophy and heterotrophy, acquired phototrophy (AcPh) encompasses a suite of endosymbiotic and organelle retention interactions, that range from facultative to obligate. AcPh is a common phenomenon in aquatic ecosystems, with endosymbiotic associations generally more prevalent in nutrient poor environments, and organelle retention typically associated with more productive ones. All AcPhs benefit from enhanced growth due to access to photosynthetic products; however, the degree of metabolic integration and dependency in the host varies widely. AcPh is found in at least four of the major eukaryotic supergroups, and is the driving force in the evolution of secondary and tertiary plastid acquisitions. Mutualistic resource partitioning characterizes most algal endosymbiotic interactions, while organelle retention is a form of predation, characterized by nutrient flow (i.e., growth) in one direction. AcPh involves adaptations to recognize specific prey or endosymbionts and to house organelles or endosymbionts within the endomembrane system but free from digestion. In many cases, hosts depend upon AcPh for the production of essential nutrients, many of which remain obscure. The practice of AcPh has led to multiple independent secondary and tertiary plastid acquisition events among several eukaryote lineages, giving rise to the diverse array of algae found in modern aquatic ecosystems. This article highlights those AcPhs that are model research organisms for both metazoans and protists. Much of the basic biology of AcPhs remains enigmatic, particularly (1) which essential nutrients or factors make certain forms of AcPh obligatory, (2) how hosts regulate and manipulate endosymbionts or sequestered organelles, and (3) what genomic imprint, if any, AcPh leaves on non

  19. Consumer-driven nutrient dynamics in freshwater ecosystems: from individuals to ecosystems.

    Atkinson, Carla L; Capps, Krista A; Rugenski, Amanda T; Vanni, Michael J

    2016-12-23

    The role of animals in modulating nutrient cycling [hereafter, consumer-driven nutrient dynamics (CND)] has been accepted as an important influence on both community structure and ecosystem function in aquatic systems. Yet there is great variability in the influence of CND across species and ecosystems, and the causes of this variation are not well understood. Here, we review and synthesize the mechanisms behind CND in fresh waters. We reviewed 131 articles on CND published between 1973 and 1 June 2015. The rate of new publications in CND has increased from 1.4 papers per year during 1973-2002 to 7.3 per year during 2003-2015. The majority of investigations are in North America with many concentrating on fish. More recent studies have focused on animal-mediated nutrient excretion rates relative to nutrient demand and indirect impacts (e.g. decomposition). We identified several mechanisms that influence CND across levels of biological organization. Factors affecting the stoichiometric plasticity of consumers, including body size, feeding history and ontogeny, play an important role in determining the impact of individual consumers on nutrient dynamics and underlie the stoichiometry of CND across time and space. The abiotic characteristics of an ecosystem affect the net impact of consumers on ecosystem processes by influencing consumer metabolic processes (e.g. consumption and excretion/egestion rates), non-CND supply of nutrients and ecosystem nutrient demand. Furthermore, the transformation and transport of elements by populations and communities of consumers also influences the flow of energy and nutrients across ecosystem boundaries. This review highlights that shifts in community composition or biomass of consumers and eco-evolutionary underpinnings can have strong effects on the functional role of consumers in ecosystem processes, yet these are relatively unexplored aspects of CND. Future research should evaluate the value of using species traits and abiotic

  20. Nutrient Storage and Release Following Perturbation of an Experimental Forest Ecosystem

    Havig, J. R.; Keller, C. K.

    2001-12-01

    Chemical weathering and chemical denudation are being studied in a "sandbox" red pine ecosystem at the Hubbard Brook Experimental Forest. The sandbox is a 7.5 m x 7.5 m x 1.5 m granitic sand-filled lysimeter with suction porewater samplers installed at 15 cm, 35 cm, and 95 cm depths, and a tipping-bucket drainage collector at the bottom. In May of 1998, photosynthetic input to the subsurface was halted by removal of the above-ground portions of the 15-year-old trees. The purpose of this perturbation was to study subsurface hydrology and decomposition in the absence of physical disturbance, and their effects on nutrient loss from the system. Elimination of transpiration has increased water and nutrient export while drainage concentrations have remained the same if not increased. The greatest concentration increases for all ions occur at the 15 cm porewater depth. Potassium and chloride both show large increases shortly after the tree cut, and calcium, magnesium and nitrate all show large increases the second growing season after the tree cut. Sodium and fluoride concentrations have shown little change in response to the cut. For all ions, concentrations are markedly independent of discharge and porewater residence time, i.e. there is little evidence of kinetic water-mineral reactions. Nutrient mass balances and nutrient ratios in drainage indicate that most of the nutrients released are from the litter layer. Results of this study suggest that a combination of soil-chemical and decomposition mechanisms along subsurface flow pathways can attenuate nutrient loss from perturbed sites, whereas surface runoff pathways may amplify nutrient loss.

  1. Soil microbial nutrient constraints along a tropical forest elevation gradient: a belowground test of a biogeochemical paradigm

    A. T. Nottingham

    2015-04-01

    Full Text Available Aboveground primary productivity is widely considered to be limited by phosphorus (P availability in lowland tropical forests and by nitrogen (N availability in montane tropical forests. However, the extent to which this paradigm applies to belowground processes remains unresolved. We measured indices of soil microbial nutrient status in lowland, sub-montane and montane tropical forests along a natural gradient spanning 3400 m in elevation in the Peruvian Andes. With increasing elevation there were marked increases in soil concentrations of total N, total P, and readily-extractable P, but a decrease in N mineralization determined by in situ resin bags. Microbial carbon (C and N increased with increasing elevation, but microbial C:N:P ratios were relatively constant, suggesting homeostasis. The activity of hydrolytic enzymes, which are rich in N, decreased with increasing elevation, while the ratios of enzymes involved in the acquisition of N and P increased with increasing elevation, further indicating a shift in the relative demand for N and P by microbial biomass. We conclude that soil microorganisms shift investment in nutrient acquisition from P to N between lowland and montane tropical forests, suggesting that different nutrients regulate soil microbial metabolism and the soil carbon balance in these ecosystems.

  2. Nutrient release, recovery and removal from waste sludge of a biological nutrient removal system.

    Wang, Yi; Zheng, Shu-Jian; Pei, Li-Ying; Ke, Li; Peng, Dang-Cong; Xia, Si-Qing

    2014-01-01

    The uncontrolled release of nutrients from waste sludge results in nitrogen and phosphorus overloading in wastewater treatment plants when supernatant is returned to the inlet. A controlled release, recovery and removal of nutrient from the waste sludge of a Biological Nutrient Removal system (BNR) are investigated. Results showed that the supernatant was of high mineral salt, high electrical conductivity and poor biodegradability, in addition to high nitrogen and phosphorus concentrations after the waste sludge was hydrolysed through sodium dodecyl sulphate addition. Subsequently, over 91.8% of phosphorus and 10.5% of nitrogen in the supernatants were extracted by the crystallization method under the conditions of 9.5 pH and 400 rpm. The precipitate was mainly struvite according to X-ray diffraction and morphological examination. A multistage anoxic-oxic Moving Bed Biofilm Reactor (MBBR) was then adopted to remove the residual carbon, nitrogen and phosphorus in the supernatant. The MBBR exhibited good performance in simultaneously removing carbon, nitrogen and phosphorus under a short aeration time, which accounted for 31.25% of a cycle. Fluorescence in situ hybridization analysis demonstrated that nitrifiers presented mainly in floc, although higher extracellular polymeric substance content, especially DNA, appeared in the biofilm. Thus, a combination of hydrolysis and precipitation, followed by the MBBR, can complete the nutrient release from the waste sludge of a BNR system, recovers nutrients from the hydrolysed liquor and removes nutrients from leftovers effectively.

  3. Bioactive Nutrients and Nutrigenomics in Age-Related Diseases

    Tania Rescigno

    2017-01-01

    Full Text Available The increased life expectancy and the expansion of the elderly population are stimulating research into aging. Aging may be viewed as a multifactorial process that results from the interaction of genetic and environmental factors, which include lifestyle. Human molecular processes are influenced by physiological pathways as well as exogenous factors, which include the diet. Dietary components have substantive effects on metabolic health; for instance, bioactive molecules capable of selectively modulating specific metabolic pathways affect the development/progression of cardiovascular and neoplastic disease. As bioactive nutrients are increasingly identified, their clinical and molecular chemopreventive effects are being characterized and systematic analyses encompassing the “omics” technologies (transcriptomics, proteomics and metabolomics are being conducted to explore their action. The evolving field of molecular pathological epidemiology has unique strength to investigate the effects of dietary and lifestyle exposure on clinical outcomes. The mounting body of knowledge regarding diet-related health status and disease risk is expected to lead in the near future to the development of improved diagnostic procedures and therapeutic strategies targeting processes relevant to nutrition. The state of the art of aging and nutrigenomics research and the molecular mechanisms underlying the beneficial effects of bioactive nutrients on the main aging-related disorders are reviewed herein.

  4. Nutrigenomics: the role of nutrients in gene expression.

    Dang, Tarana Singh; Walker, Mark; Ford, Dianne; Valentine, Ruth A

    2014-02-01

    Improved understanding of the mechanism behind periodontal tissue destruction, the potential protective role of nutrients and the advent of modern genomic measurement tools has led to an increased interest in the association between nutrition and periodontal disease. To date, evidence for a direct link between periodontal disease and nutrition has come mainly from large observational cross-sectional studies or very small double-blind randomized supplementation trials, with a large proportion finding no significant association between the nutrient being analyzed and markers of periodontal disease status. The advent of the 'genomic era' has introduced the concept of nutrigenomic studies, which aim to reveal the relationship between nutrition and the genome to provide a scientific basis for improved public health through dietary means. Used alongside relatively inexpensive high-throughput technology, this will allow the effect of diet on the etiology of periodontal disease to be studied in greater detail. As it is extremely likely that interactions between genotype and diet are important in determining the risk of the most common complex diseases, it is highly probable that these interactions will be important in determining periodontal disease risk. Numerous nutritional genetic studies where the outcome measures have been markers of disease risk, most notably cardiovascular disease and cancer, provide proof of principle, highlight the importance of understanding these interactions and illustrate where the effect of dietary modification on periodontal disease progression may have been overlooked previously by observational studies.

  5. Nutrient retranslocation in forest species in the Brazilian Amazon

    Murilo Rezende Machado

    2016-01-01

    Full Text Available Internal retranslocation is an important mechanism for nutrient conservation in plants, which depends on different factors. However, there are little data about this subject, especially on tropical forest species. This study aimed to evaluate the macronutrient retranslocation dynamic and the influence of ecological (P: pioneer x NP: non-pioneer and phenological (ND: non-deciduous x D: semideciduous / deciduous characteristics on the macronutrient content of leaves of five tree species on monospecific plantations in the Brazilian Amazon: Acacia mangium Willd., Parkia decussata Ducke, Dipteryx odorata (Aublet Willd., Jacaranda copaia (Aubl. D. Don and Swietenia macrophylla King. Photosynthetically active green leaves and senescent leaves (leaf litter were collected. Retranslocation was estimated through an equation proposed by Attiwill, Guthrie and Leuning (1978. The pioneer species presented higher foliar contents of N; the non-pioneer species presented higher contents of K, Ca and S; and the results were inconclusive for P and Mg. The deciduous species presented higher foliar contents of K and of P, whereas the foliar contents of N, Ca, Mg and S were virtually identical between the phenological groups. The internal retranslocation of foliar nutrients in pioneer and non-deciduous species was higher than that of non-pioneer and deciduous species.

  6. Salinization Enhances Mobilization of Nutrients from Sediments to Streams

    Haq, S.; Kaushal, S.; Hohman, S.; Coplin, J.; Duan, S.

    2015-12-01

    Many regions of the U.S. and elsewhere are experiencing increased salinization of freshwater due to the widespread application of road salts. Increased salinization has the potential to release stored nutrients from sediments, decrease biodiversity, and perturb water quality. We conducted laboratory experiments to investigate the potential effects of road salt (NaCl) on nutrient mobilization from sediments to stream water. Sediments and stream water were incubated from 2 urbanizing watersheds of the Chesapeake Bay in the Baltimore-Washington Metropolitan area. Stream sediment was incubated from 11 routinely monitored streams exhibiting a land use gradient within the Baltimore Ecosystem Study Long-Term Ecological Research (BES LTER) site and Anacostia River watershed. Our results indicate that salinization increased the release of soluble reactive phosphorus and total dissolved nitrogen at all sites. The release of dissolved organic carbon and dissolved inorganic carbon varied between sites, and these differential responses may be due to: stream sediment composition, organic matter content, and ambient water quality. The magnitude and frequency of road salt application may be amplified in the near future due to the interactive effects of climate variability and urbanization, and our research suggests this can have water quality and ecological implications for freshwater ecosystems. Further research is necessary to elucidate driving mechanisms of changes in sediment biogeochemical cycles in response to salinization and the temporal response of freshwater ecosystems.

  7. Host control and nutrient trading in a photosynthetic symbiosis.

    Dean, Andrew D; Minter, Ewan J A; Sørensen, Megan E S; Lowe, Christopher D; Cameron, Duncan D; Brockhurst, Michael A; Jamie Wood, A

    2016-09-21

    Photosymbiosis is one of the most important evolutionary trajectories, resulting in the chloroplast and the subsequent development of all complex photosynthetic organisms. The ciliate Paramecium bursaria and the alga Chlorella have a well established and well studied light dependent endosymbiotic relationship. Despite its prominence, there remain many unanswered questions regarding the exact mechanisms of the photosymbiosis. Of particular interest is how a host maintains and manages its symbiont load in response to the allocation of nutrients between itself and its symbionts. Here we construct a detailed mathematical model, parameterised from the literature, that explicitly incorporates nutrient trading within a deterministic model of both partners. The model demonstrates how the symbiotic relationship can manifest as parasitism of the host by the symbionts, mutualism, wherein both partners benefit, or exploitation of the symbionts by the hosts. We show that the precise nature of the photosymbiosis is determined by both environmental conditions (how much light is available for photosynthesis) and the level of control a host has over its symbiont load. Our model provides a framework within which it is possible to pose detailed questions regarding the evolutionary behaviour of this important example of an established light dependent endosymbiosis; we focus on one question in particular, namely the evolution of host control, and show using an adaptive dynamics approach that a moderate level of host control may evolve provided the associated costs are not prohibitive.

  8. What drives interannual variability of hypoxia in Chesapeake Bay: Climate forcing versus nutrient loading?

    Li, Ming; Lee, Younjoo J.; Testa, Jeremy M.; Li, Yun; Ni, Wenfei; Kemp, W. Michael; Di Toro, Dominic M.

    2016-03-01

    Oxygen depletion in estuaries is a worldwide problem with detrimental effects on many organisms. Although nutrient loading has been stabilized for a number of these systems, seasonal hypoxia persists and displays large year-to-year variations, with larger hypoxic volumes in wetter years and smaller hypoxic volumes in drier years. Data analysis points to climate as a driver of interannual hypoxia variability, but nutrient inputs covary with freshwater flow. Here we report an oxygen budget analysis of Chesapeake Bay to quantify relative contributions of physical and biogeochemical processes. Vertical diffusive flux declines with river discharge, whereas longitudinal advective flux increases with river discharge, such that their total supply of oxygen to bottom water is relatively unchanged. However, water column respiration exhibits large interannual fluctuations and is correlated with primary production and hypoxic volume. Hence, the model results suggest that nutrient loading is the main mechanism driving interannual hypoxia variability in Chesapeake Bay.

  9. Towards a Theory of Language Acquisition

    Kampen, Jacqueline van

    2008-01-01

    "We have seen at the workshop a diversity of measurements and a no less diverse amount of different phenomena. Shared areas were acquisition phenomena in Romance languages and more general: the beginnings for a true theory of language acquisition. I will not attempt to evaluate the various contribut

  10. Application of Krashen's L2 Acquisition Hypothesis

    范丽

    2008-01-01

    In the search for better approaches to teaching in China,Krashen's second language acquisition theory comes into their sight.In this essay some problems with existing teaching practice are first of all listed.Then Krmhen's second language acquisition theories are introduced.In the third part,a detailed instruction of the theory is given.

  11. Webpage Segments Classification with Incremental Knowledge Acquisition

    Guo, Wei; Kim, Yang Sok; Kang, Byeong Ho

    This paper suggests an incremental information extraction method for social network analysis of web publications. For this purpose, we employed an incremental knowledge acquisition method, called MCRDR (Multiple Classification Ripple-Down Rules), to classify web page segments. Our experimental results show that our MCRDR-based web page segments classification system successfully supports easy acquisition and maintenance of information extraction rules.

  12. Academic Listening: A Source of Vocabulary Acquisition?

    Vidal, Karina

    2003-01-01

    Presents a study of the acquisition of English-as-a-Foreign-Language vocabulary through academic listening. Explored the effects of EFL proficiency and lecture comprehension on vocabulary acquisition as well as the relationship between vocabulary gain and the following factors: frequency of occurrence, types of word, type of word elaboration, and…

  13. Acquisition Initiatives Review-Phase 2

    2006-02-01

    Actions to Strengthen the TRA Process................................. II-9 III. Improving Acountability in the Acquisition Workforce A. Clear Command...BETTER ACOUNTABILITY IN THE ACQUISITION WORKFORCE In its simplest terms, the Packard Commission recommended that DoD implement an industry model with...evaluation staff. II-10 This page is intentionally left blank. III-1 III. IMPROVING ACOUNTABILITY IN THE

  14. Risk Management Programs for Defense Acquisition Systems

    2007-11-02

    The audit objective was to evaluate the effectiveness of risk management programs for Defense acquisition systems. Specifically, we determined whether DoD risk management policies and procedures for Defense acquisition systems were effectively implemented and what impact risk management programs bad on reducing program risks and costs. We also reviewed management controls as they applied to the audit objectives.

  15. 75 FR 10567 - Commerce Acquisition Regulation (CAR)

    2010-03-08

    ... Commerce 48 CFR Chapter 13 Commerce Acquisition Regulation (CAR); Final Rule #0;#0;Federal Register / Vol. 75, No. 44 / Monday, March 8, 2010 / Rules and Regulations#0;#0; ] DEPARTMENT OF COMMERCE 48 CFR Chapter 13 RIN 0605-AA26 Commerce Acquisition Regulation (CAR) AGENCY: Department of Commerce...

  16. 78 FR 45168 - Acquisition Regulations: Export Control

    2013-07-26

    ... Parts 925, 952 and 970 RIN 1991-AB99 Acquisition Regulations: Export Control AGENCY: Department of... Department of Energy Acquisition Regulation (DEAR) to add export control requirements applicable to the... business August 23, 2013. ADDRESSES: You may submit comments, identified by ``DEAR: Export Control and...

  17. Programmatic Ahistoricity in Second Language Acquisition Theory.

    Thomas, Margaret

    1998-01-01

    Suggests that, despite some perceptions, second language acquisition theory has a history. Disputes arguments that might be formulated to support the notion that second language acquisition theory has no relevant earlier history, enumerates consequences of maintaining this belief, and speculates about benefits to the field that might accrue from…

  18. The Acquisition of L2 Phonology

    Wojtaszek, Adam; Arabski, Janusz

    2011-01-01

    The Acquisition of L2 Phonology is a wide-ranging new collection which focuses on various aspects of the acquisition of an L2 phonological system. The authors are researchers and practitioners from five different countries. The volume has been divided into three major sections. Phonetic Analysis presents five studies of language learners in both…

  19. 78 FR 35195 - Acquisition Regulations: Export Control

    2013-06-12

    ... Parts 925, 952, and 970 RIN 1991-AB99 Acquisition Regulations: Export Control AGENCY: Department of... amend the Department of Energy Acquisition Regulation (DEAR) to add export control requirements... ``DEAR: Export Control and RIN 1991-AB99,'' by any of the following methods: Federal eRulemaking...

  20. Student Modelling for Second Language Acquisition.

    Bull, Susan

    1994-01-01

    Describes the student model of an intelligent computer-assisted language learning (CALL) system that is based on current theories in the field of second-language acquisition. Highlights include acquisition order of the target rules; language learning strategies; language transfer; language awareness; and student reactions. (Contains seven…

  1. Teacher Trainees' Information Acquisition in Lesson Planning

    Tanni, Mikko

    2012-01-01

    Introduction: Few studies have addressed teacher trainees' information acquisition in the context of a task. The paper reports findings from an empirical study on teacher trainees' use of information (seeking) channels and sources, and their modes of information acquisition in lesson planning. Method: Semi-structured (retrospectively held)…

  2. Managing in a merger and acquisition era.

    Holdren, R C

    1990-01-01

    Medical group administrators are quickly learning what big business has known for years-mergers and acquisitions represent a new and powerful option. If this option is to be employed successfully, however, group management has to understand the terms and be prepared well before merger or acquisition talk begins.

  3. Learning Strategies in Acquisition of Medical Vocabulary

    田俊英; 蒋东坡

    2016-01-01

    Medical vocabulary consists of so many words and terms.Medical students are often terrified by large vocabulary.The paper aimed to analyze the problems lie in acquisition of medical vocabulary,review literature of learning strategies of medical vocabulary,and offers a few simple rules for students to follow to facilitate their acquisition of medical vocabulary.

  4. 16 CFR 801.4 - Secondary acquisitions.

    2010-01-01

    ... corporation. B's voting securities are cancelled, and B's shareholders are to receive cash in return. Since S... acquired, by virtue of § 801.2(d)(2) “A” is an acquiring person only. The acquisition of the minority... thereby gains control of that subsidiary, B will make secondary acquisitions of any minority holdings...

  5. EBT data acquisition and analysis system

    Burris, R.D.; Greenwood, D.E.; Stanton, J.S.; Geoffroy, K.A.

    1980-10-01

    This document describes the design and implementation of a data acquisition and analysis system for the EBT fusion experiment. The system includes data acquisition on five computers, automatic transmission of that data to a large, central data base, and a powerful data retrieval system. The system is flexible and easy to use, and it provides a fully documented record of the experiments.

  6. Distributed multiprotocol acquisition network for environmental data

    Barone, Fabrizio; De Rosa, Rosario; Milano, Leopoldo; Qipiani, Ketevan

    2003-03-01

    The acquisition and storage of large amount of data coming from distributed environmental sensors of different kind can be solved with the aid of a network between the acquisition subsystems, but problems can arise if they are not homogeneous. In this case the network should be as flexible as possible to ensure modularity and connectivity. In this work we describe the development and testing of a network based acquisition system. The network uses, where possible, commercial products, based on different standards, in order to increase the availability of its components, as well as its modularity. In addition it is completely independent from proprietary hardware and software products. In particular we tested an acquisition network based on multiple transmission protocol, like wireless and cabled RS232 and Fast Ethernet, which includes the acquisition, archiving and data analysis systems. Each acquisition subsystem can get time from satellite using GPS, and is able to monitor seismic activity, temperature, pressure, humidity and electromagnetic data. The sampling frequency and the dynamics of the acquired data can be matched to the characteristics of each probe. All the acquisition stations can use different platform as well as different operating systems. Tests have been performed to evaluate the capability of long acquisition periods and the fault tolerance of the whole system.

  7. Input and Intake in Language Acquisition

    Gagliardi, Ann C.

    2012-01-01

    This dissertation presents an approach for a productive way forward in the study of language acquisition, sealing the rift between claims of an innate linguistic hypothesis space and powerful domain general statistical inference. This approach breaks language acquisition into its component parts, distinguishing the input in the environment from…

  8. Multilingual Language Acquisition in Canada and Germany.

    Hufeisen, Britta

    1995-01-01

    Examines multilingual settings in Canada and Germany and explores the differentiation between second- and third-language acquisition as well as the differentiation between acquisition and learning. The article outlines priority areas for further research and presents the prospects for a greater recognition of multilingualism as a resource in…

  9. Acquisitions and Real Options : The Greenfield Alternative

    Brouthers, Keith D.; Dikova, Desislava

    2010-01-01

    P>Although acquisitions are a popular way to enter new markets, empirical evidence tends to indicate few benefits accrue to acquiring firms. This might be the case because firms use acquisitions when they should be employing an alternative mode of expansion. Applying real options theory to this issu

  10. Child Second Language Acquisition of Syntax.

    Lakshmanan, Usha

    1995-01-01

    Reviews recent research in universal grammar-based child second language acquisition (SLA) research, arguing that child SLA studies can better explore the role of biological factors in language acquisition and strengthen the links between SLA and linguistic theory. (129 references) (MDM)

  11. Studies in First and Second Language Acquisition.

    Eckman, Fred R., Ed.; Hastings, Ashley J., Ed.

    Papers presented at a 1977 symposium on language acquisition held at the University of Wisconsin/Milwaukee are included. Contents are as follows: "Assumptions, Methods and Goals in Language Acquisition Research" (Sheldon); "The Mother as LAD: Interaction between Order and Frequency of Parental Input and Child Production"…

  12. Second Language Acquisition and Universal Grammar.

    White, Lydia

    1990-01-01

    Discusses the motivation for Universal Grammar (UG), as assumed in the principles and parameters framework of generative grammar (Chomsky, 1981), focusing on the logical problem of first-language acquisition and the potential role of UG in second-language acquisition. Recent experimental research regarding the second-language status of the…

  13. 40 CFR 35.2210 - Land acquisition.

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Land acquisition. 35.2210 Section 35.2210 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2210 Land acquisition....

  14. Integration and Reuse in Cognitive Skill Acquisition

    Salvucci, Dario D.

    2013-01-01

    Previous accounts of cognitive skill acquisition have demonstrated how procedural knowledge can be obtained and transformed over time into skilled task performance. This article focuses on a complementary aspect of skill acquisition, namely the integration and reuse of previously known component skills. The article posits that, in addition to…

  15. Gerber Technology Announces Acquisition of Yunique Solutions

    2009-01-01

    On Dec.4, 2009, Gerber Technology, announced the strategic acquisition of Yunique Solutions, Inc., developer of the fashion industry’s top-ranked PLM solution. This acquisition will ensure that Gerber provides an innovative end-to-end solution with user productivity and enterprise connectivity at its core.

  16. Leading Nonferrous Enterprises Kicked Off Acquisitions Frequently

    2015-01-01

    The huge adjustment in the stock market since June inadvertently opened another door:In the sluggish nonferrous industry,a number of"long stagnant"asset acquisition projects have kicked off.Recently,Xiamen Tungsten disclosed details of its acquisition of Jiangxi Tungsten assets,

  17. A Three—Stage Knowledge Acquisition Method

    曹存根; 刘薇

    1995-01-01

    This paper presents and analyzes three fundamental problems in knowledge acquisition,and proposes a general method for tackling them.The method divides the whole process of knowledge acquisition into a set of almost independent pieces,each of which can be finished by knowledge engineers,experts and assistants,respectively.

  18. 32 CFR 21.605 - Acquisition.

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Acquisition. 21.605 Section 21.605 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE DoD GRANT AND AGREEMENT REGULATIONS DoD GRANTS AND AGREEMENTS-GENERAL MATTERS Definitions § 21.605 Acquisition. The acquiring (by purchase,...

  19. The Acquisition of English Pronunciation: Learners' Views.

    Cenoz, Jasone; Lecumberri, Ma Luisa Garcia

    1999-01-01

    Describes English learners' views on the acquisition of the phonetic component of English by focusing on (1) their awareness of the difficulty and importance of English pronunciation, and (2) their beliefs about influential factors in the acquisition of pronunciation and their attitudes towards English accents. Examines differences in phonetic…

  20. Data-Acquisition Systems for Fusion Devices

    van Haren, P. C.; Oomens, N. A.

    1993-01-01

    During the last two decades, computerized data acquisition systems (DASs) have been applied at magnetic confinement fusion devices. Present-day data acquisition is done by means of distributed computer systems and transient recorders in CAMAC systems. The development of DASs has been technology driv